Page 1

VerĂśffentlichungen Published Papers on

ossceram

Literatursammlung Ăźber synthetisches Knochenersatzmaterial. Literature list about synthetic bone substitude material.


SOLUTION ossceram

Lösungen für die orale Rehabilitation ... bredent group

brecision implant REF 000 302 0D

whiteSKY REF 000 168 0D

whiteSKY Manual REF 000 288 0D

2

mini1SKY FRP REF 000 298 0D

SKY fast & fixed REF 000 200 0D

SKY uni.fit REF 000 280 0D

SKYplanX REF 000 269 0D

Systemvorstellung SKY REF 000 250 0D

SKY esthetic line REF 000 267 0D

alveoprotect REF 000 306 0D

ossceram nano REF 000 301 0D

UVE REF 000 169 0D

Tel. (+49) 0 73 09 / 8 72-6 00 | Fax (+49) 0 73 09 / 8 72-6 35 | www.bredent-medical.com | e-mail info-medical@bredent.com


ossceram nano Eine Analyse veröffentlichter Literatur über synthetisches Knochenersatzmaterial Seite 4

A analysis of published papers about synthetic bone substitude material Page 6

Dr. Jörg Neugebauer, Universität Köln / University of Cologne

3


ossceram Dr. Jörg Neugebauer, Universität Köln Eine Literaturanalyse mit den Suchbegriffen TCP, HA, BCP in Kombination mit dentaler Knochenaugmentationstechnik wurde durchgeführt. Knochenersatzmaterialien werden seit Jahrzehnten in der Kieferchirurgie und der Implantologie zur Defektdeckung oder zum Ausgleich von unzureichendem Knochenangebot verwendet (7, 16, 17, 21, 30). Die Erfolgswahrscheinlichkeiten der Implantate und die histologische Aufarbeitung ist dabei am besten für die Indikation der Sinusbodenelevation beschrieben (16, 17, 30, 33, 47). Für die laterale Augmentation mit Knochenersatzmaterialien können bei entsprechender Indikationsstellung vergleichbare Ergebnisse erzielt werden, sofern die Indikation und das operative Vorgehen der jeweiligen Defektgeometrie angepasst ist (16, 34). Bei der Augmentation von Defekten bei der Periimplantitistherapie werden für die angewendeten Verfahren und Materialien unterschiedliche Ergebnisse vorgestellt (5, 22). Unter den verschiedenen Materialien haben sich in den letzten Jahren zwei Gruppen durch Zellkulturuntersuchungen, tierexperimentelle und klinische Studien als besonders erfolgversprechend herauskristallisiert (2, 7, 24). Dies hat unter anderem dazu geführt, dass die Zulassungsbedingungen für TCP-Knochenersatzmaterialien in den USA gelockert wurden (26). Da bei einem synthetischen Material die Zusammensetzung im Herstellungsprozess genau gesteuert werden kann, ist nicht von antigenen Reaktionen auszugehen(39), so dass die Biokompatibilität dieser mineralisch basierten Knochenersatzmaterialien gegeben ist (36, 38) Zur Beurteilung der Knochenersatzmaterialien sind zum einen die physikochemischen Eigenschaften zu berücksichtigen (27), aber auch das Verhalten in der Zellkultur (19), um die Wechselwirkungen bei der initialen Wundheilung durch die Osteoblastenaktivität zu verifizieren. Die Knochenregeneration ist an die gleichen Prinzipien wie die Implantateinheilung mit dem Erreichen der Osteointegration zu beurteilen (46, 48). Daher ist es notwendig, dass ein modernes Knochenersatzmaterial, ähnlich wie eine Implantatoberfläche, eine bimodale Struktur aufweist. Diese ermöglicht den Osteoblastenausläufern in der initialen Differenzierungsphase die Brückenbildung zwischen mehreren Zellen und Granula, so dass die Proliferation und Differenzierung unterstützt wird. Die intrinsche Stimulation der Knochenneubildung wird dabei durch die Aktivierung der mesenchymalen Stammzellen und der Anlagerung der Osteoblasten unterstützt, die auf Grund neuerer Arbeiten auch durch die Struktur im Nano-Bereich bestimmt wird (12, 15, 18). Das letztendliche Ziel ist ein vollständiges Einscheiden mit voll aus differenzierten Osteoblasten, dass im weiteren Verlauf die Knochenmatrixproduktion unterstützt werden kann (31). Dazu ist eine unterschiedliche Porenstruktur mit Nano-, Mikro- und Makroporen notwendig, dass je nach Anlagerung und Einlagerungsverhalten der Zellen eine entsprechende Rezeptorstelle am Knochenersatzmaterial vorhanden ist (18, 38, 42). Die initiale Wundheilung des Knochens wird durch das vorhandene Kalziumphosphat des Knochenersatzmaterials gestützt (46). Da die Kalziumphosphatpräparate unterschiedliche physikochemische Eigenschaften mit der entsprechenden mechanischen Stabilität besitzen, ist es notwendig für die jeweiligen Stadien der Knochenneubildung unterschiedliche Eigenschaften anzubieten. Die Anwendung von Hydroxylapatitstrukturen konnte im Tierversuch zeigen, dass eine hohe Volumenstabilität und geringe Degradation im Vergleich Tricalziumphosphaten erreicht werden kann (10, 37). TCP wird schnell resorbiert und ermöglicht gleichzeitig einen höheren Anteil an neugebildetem Knochen im Vergleich zu Hydroxylapatitpräparaten, der mit autologen Knochen vergleichbar ist (45). Aufgrund der schnellen Degradation zeigt TCP jedoch einen Nachteil in der Volumenstabilität, da der neugebildete Knochen nicht diese Stabilität aufbauen kann, um ein Volumen aufrecht zu erhalten (35).

4

Tel. (+49) 0 73 09 / 8 72-6 00 | Fax (+49) 0 73 09 / 8 72-6 35 | www.bredent-medical.com | e-mail info-medical@bredent.com


Daher empfehlen neuere Studien ein Gemisch aus Hydroxylapatit und TCP zu verwenden (32), damit zum einen eine Leitstruktur für die neue Knochenbildung gegeben ist, zum anderen das Volumen durch die Hydroxylapatitbestandteile gesichert wird (20, 45). Diese Arbeiten aus tierexperimentellen Studien konnten auch inzwischen durch humane Biopsien und klinische Studien bestätigt werden (6, 9). Da durch die chirurgisch bedingte Entzündung es im OP-Areal zu einem ph-Wert-Abfall kommt, wird das erhöhte Infektionsrisiko der Knochenersatzmaterialen durch die damit verbundene Bakterienbesiedelung diskutiert. Dafür ist jedoch wiederum die Porengröße verantwortlich, die jedoch bei BCP-Materialien eine solche Ausprägung besitzt, dass diese nicht zu einer erhöhten Staphylococcenadhärenz führt (3). Bei der Verwendung der Knochenersatzmaterialien zeigen Präparate mit Partikeln mit einer Korngröße von 0,02 mm eine erhöhte inflammatorische Reaktion, die als Risikofaktor für die Knochenneubildung diskutiert wird (19). Deshalb wird i.d.R. bei neuen Knochenersatzmaterialien eine Korngröße ab 0,5 mm gewählt. Die Knochenneubildung in einem porösen Material mit interkonnektierenden Poren stellt per se die Voraussetzung für eine Knochenkonduktion, da in einem inerten Material das Einwachsen von Knochen in die Matrix ermöglicht wird (43). Eine Knocheninduktion durch das Knochenersatzmaterial wird allenfalls indirekt erreicht, indem durch die günstige Differenzierung der Osteoblasten damit auch simultan die pluripotenten Stammzellen stimuliert werden und somit die Knochenneubildung unterstützen (8, 14, 25, 40). Die Zugabe von knochenbildenden Proteinen ist bis heute noch nicht in einem abgesicherten praxisreifen Verfahren verfügbar, da die Wundheilungskaskade nicht auf lediglich ein Protein oder Wachstumsfaktor reagieren, sondern jeweils eine Kaskade durch verschiedenste Faktoren durchlaufen wird, damit neuer Knochen entstehen kann (11, 13). Bei der Knochenneubildung ist ferner zwischen Osteoid, Geflechtknochen und dem lammillären Knochen zu unterscheiden. In der ersten Phase bildet sich Geflechtknochen mit einer disorganisierten Struktur, der weich und eine relativ geringe mechanische Stabilität aufweist. Diese Knochenneubildung erfolgt im Bereich von 30 – 60 µm/Tag. Die Ausdifferenzierung des Knochens als lammillär strukturierte Spongiosa und Kortikalis erfordert einen umfangreichen Knochenumbau mit der Reorganisation der Kollagenfasern und Mineralstruktur, die in der Kortikalis im Bereich von 0,6-1 µm und in der Spongiosa mit einer Geschwindigkeit von 1-2 µm/Tag erfolgt (4, 28, 29) Knochen stellt sich als komplexes dynamisches Gewebe dar und besteht aus ca. 60 bis 65 % Hydroxylapatit, 25 bis 30% organische Matrix und ca. 10% Wasser, wobei sich der Anteil der organischen Matrix mit zunehmenden Alter verändert (44). Neben der mineralischen Struktur sind die organischen Komponenten vor allem Kollagen Typ 1 und verschiedene Proteine wie Osteocalzin, Osteopontin, Fibronektin und die verschiedenen Transforming Growth Faktoren für die biologische Stabilität verantwortlich. Daher muss es gewährleistet sein, dass bei der Anwendung von Knochenersatzmaterial, dass per se avital ist, ein Kontakt zu vitalem Knochen notwendig ist, damit eine Neoangiogenese zur Vaskularisierung des aufgebauten Areal erfolgt (1, 23). Dies erfordert eine schnelle Knochenheilung mit Geflechtknochen. Diese kann leicht im TCP Material erreicht werden. Für die Ausdifferenzierung des Knochens ist dann eine Volumenstabilität und Ausschluss einer mechanischen Belastung notwendig (41). Eine Vergleichsstudie zur Beurteilung der unterschiedlichen Mischungsverhältnisse von HA zur TCP im Verhältnis 60:40, 80:20, 20:80 zeigte, dass die Variante mit 60:40 das stabilste Verhältnis der Knochenneubildung über einen Zeitraum von 1 Jahr im Tierversuch ergab (10).

5


ossceram Dr. JĂśrg Neugebauer, University Cologne/Germany An analysis of the literature with the search terms TCP, HA, BCP in combination with dental bone augmentation technology was carried out. Bone replacement materials have been used for decades in maxillary surgery and for defect coverage or to even out inadequate bone surface (7, 16, 17, 21, 30). The prospects for the success of the implants and the histological reconditioning have been best described for the indication of sinus oor elevation (16, 17, 30, 33, 47). For lateral aug-mentation with bone replacement material, if there are corresponding indications, comparable results can be achieved, to the extent that the indication and the surgical procedure is adapted to the respective defect geometry (16, 34). In the augmentation of defects in the treatment of peri-implantitis, various results are presented for the pro-cedures and materials used (5, 22). Among the various materials, over the last few years, cell culture studies, animal-experimental and clinical studies have singled out two groups as particularly promising (2, 7, 24). This has led, among other things, to the loosening of approval requirements for TCP bone replacement materials in the US (26). Since for a synthetic material, the composition can be precisely controlled in the manufacturing process, no antigen reactions need be taken into consideration (39), so that the biocompatibility of these mineral-based bone replacement materials can be assumed (36, 38) In order to evaluate the bone replacement materials, one must consider on the one hand the physicochemical properties (27), but also behavior in cell cultures (19), in or-der to verify the interactions in the initial wound healing through osteoblast activity. Bone regeneration must be evaluated under the same principles as the implant heal-ing, with the achievement of osteointegration (46, 48). It is therefore necessary that a modern bone replacement material, like an implant surface, exhibit a bimodal struc-ture. This allows the osteoblast offshoots in the initial differentiation phase to build bridges among several cells and granules so that proliferation and differentiation are supported. The intrinsic stimulation of the new bone formation is thus supported by the activation of the mesenchymal stem cells and the adsorption of, which, based on recent work is also supported by the structure in the nano range (12, 15, 18). The ďŹ nal goal is a complete splitting with fully-differentiated osteoblasts, that will con-tinue to allow support of the bone matrix production (31). For this, a variable pore structure with nano-, micro-, and macro-pores is needed, so that, depending on adsorption and deposit characteristics of the cells, a corresponding receptor cell is present in the bone replacement material (18, 38, 42). The initial wound healing of the bone is supported by the calcium phosphate present in the bone replacement material (46). Since calcium phosphate preparations have varying physico-chemical properties with the corresponding mechanical stability, it is necessary to offer varying properties for the respective stages of new bone formation. The use of hydroxylapatite structures showed in animal studies that a high volume stability and low degradation can be attained in comparison to tricalcium phosphates (10, 37). TCP is quickly resorbed and allows at the same time for a larger proportion of newly-formed bone in comparison to hydroxylapatite preparations, which is compa-rable to autologous bone(45). Due to its quick degradation, however, TCP does pre-sent a disadvantage in volume stability, since the newly-formed bone cannot build up this stability in order to maintain the volume (35). For this reason, more recent studies suggest the use of a mixture of hydroxylapatite and TCP(32), so that on the one hand, there is a lead for the new bone formation, and at the same time, the volume 6

Tel. (+49) 0 73 09 / 8 72-6 00 | Fax (+49) 0 73 09 / 8 72-6 35 | www.bredent-medical.com | e-mail info-medical@bredent.com


is secured by the hydroxylapatite components (20, 45). This work in animal experimental studies has meanwhile been confirmed in human biopsies and clinical studies (6, 9). Since there is a decrease in pH value as a result of the surgically-induced irritation in the surgical area, the increased risk of infection of the bone replacement materials through the associated bacterial colonization is discussed. Here, too, the pore size is critical; however, in BCP materials this is so distinctive that it does not lead to increased adherence of staphylococci (3). In the use of bone replacement materials, preparations with micro-particles 20 µm exhibit an increased inflammatory reaction, which is discussed as a risk factor for new bone formation (19). New bone formation in a porous material with interconnect-ing pores is in itself a precondition for bone conduction, since an inert material facili-tates the bone growing into the matrix (43). However, bone induction by means of the bone replacement material is nevertheless achieved indirectly, in that by means of the favorable differentiation of osteoblasts, the pluripotent stem cells are also simultaneously stimulated, and new bone forma-tion is supported (8, 14, 25, 40). The addition of bonebuilding proteins is not yet currently available in a safe, practice-ready procedure, since the wound healing cascades do not react to only one protein or growth factor, but each cascade will run through the most varied factors, so that new bone can be created (11, 13). In new bone formation, one must also differentiate among osteoid, primitive bone and lamellar bone. In the first phase, primitive bone with a disorganized structure is formed, which is soft and exhibits a relatively low mechanical stability. The new bone formation takes place in the range of 30 – 60 µm/day. The differentiation of the bone as lamellar-structured spongy bone and cortical bone requires extensive bone restructuring with reorganization of the collagen fibers and mineral structure, which takes place in the cortical bone in the range of 0,6-1 µm and in the spongy bone at a rate of 1-2 µm/day (4, 28, 29) Bone constitutes a complex and dynamic tissue and consists of approximately 60 to 65 % hydroxylapatite, 25 to 30% organic matrix and approximately 10% water, whe-reby the percentage of the organic matrix changes with advancing age (44). In addition to the mineral structure, the organic components, primarily type 1 collagen and various proteins such as osteocalcine, osteopontine, fibronectin and the various transforming growth factors, are responsible for the biological stability. It must therefore be assured in the use of bone replacement material, which is by nature non-vital, that there is a contact to vital bone so that the formation of new blood vessels (neoangiogenesis) occurs for the vascularization of the rebuilt area (1, 23). This demands fast bone healing with primitive bone. This can easily be achieved in the TCP material. Then, for the differentiation of the bone, volume stability and the prevention of any mechanical stress is required (41). A comparative study to assess the varying mixing rations of HA to TCP in ratios of 60:40, 80:20, 20:80 showed that the 60:40 variant resulted in the most stable ratio of new bone formation over a period of 1 year in animal experiments (10).

7


ossceram

Literatursammlung 端ber synthetisches Knochenersatzmaterial

Literature list about synthetic bone substitude material

8

Tel. (+49) 0 73 09 / 8 72-6 00 | Fax (+49) 0 73 09 / 8 72-6 35 | www.bredent-medical.com | e-mail info-medical@bredent.com


1 J Orthop Res, 2009;27:155-61 Subcutaneous-induced membranes have no osteoinductive effect on mac-roporous HA-TCP in vivo. Catros S, Zwetyenga N, Bareille R, Brouillaud B, Renard M, Amedee J, Fricain JC. Seite / Page 12 2 J Biomed Mater Res B Appl Biomater, 2009;88:611-8 Micro-computed tomographic analysis of bone healing subsequent to graft placement. Chopra PM, Johnson M, Nagy TR, Lemons JE. Seite / Page 12 3 J Med Microbiol, 2009;58:132-7 Influence of surface porosity and pH on bacterial adherence to hydroxyapatite and biphasic calcium phosphate bioceramics. Kinnari TJ, Esteban J, Martin-de-Hijas NZ, Sanchez-Munoz O, Sanchez-Salcedo S, Colilla M, Vallet-Regi M, Gomez-Barrena E. Seite / Page 12 4 Clin Implant Dent Relat Res, 2009;11:41-51 Peri-implant bone organization under immediate loading conditions: collagen fiber orientation and mineral density analyses in the minipig model. Traini T, Neugebauer J, Thams U, Zoller JE, Caputi S, Piattelli A. Seite / Page 13 5 J Clin Periodontol, 2008;35:316-32 Surgical treatment of peri-implantitis. Claffey N, Clarke E, Polyzois I, Renvert S. Seite / Page 13 6 Clin Oral Implants Res, 2008;19:796-803 Maxillary sinus grafting with Bio-Oss or Straumann Bone Ceramic: histomorphometric results from a randomized controlled multicenter clinical trial. Cordaro L, Bosshardt DD, Palattella P, Rao W, Serino G, Chiapasco M. Seite / Page 13 7 Cochrane Database Syst Rev, 2008:CD003607 Interventions for replacing missing teeth: bone augmentation techniques for dental implant treatment. Esposito M, Grusovin MG, Kwan S, Worthington HV, Coulthard P. Seite / Page 14 8 Biomaterials, 2008;29:1177-88 Osteogenicity of biphasic calcium phosphate ceramics and bone autograft in a goat model. Fellah BH, Gauthier O, Weiss P, Chappard D, Layrolle P. Seite / Page 14

9 A pilot study. Int J Periodontics Restorative Dent, 2008;28:273-81 Histomorphometric comparison of a biphasic bone ceramic to anorganic bovine bone for sinus augmentation: 6- to 8-month postsurgical assessment of vital bone formation. Froum SJ, Wallace SS, Cho SC, Elian N, Tarnow DP. Seite / Page 15 10 J Biomed Mater Res B Appl Biomater, 2008 Comparative study of biphasic calcium phosphates with different HA/TCP ratios in mandibular bone defects. A long-term histomorphometric study in minipigs. Jensen SS, Bornstein MM, Dard M, Bosshardt DD, Buser D. Seite / Page 15 11 Clin Oral Implants Res, 2008;19:539-45 Effect of platelet-rich plasma on bone regeneration in dentistry: a systematic review. Plachokova AS, Nikolidakis D, Mulder J, Jansen JA, Creugers NH. Seite / Page 15 12 Acta Biomater, 2008 Calcium phosphate-based particles influence osteo genic maturation of human mesenchymal stem cells. Saldana L, Sanchez-Salcedo S, Izquierdo-Barba I, Bensiamar F, Munuera L, Vallet-Regi M, Vilaboa N. Seite / Page 16 13 Clin Periodontol, 2008;35:168-72 Advances in bone augmentation to enable dental implant placement: Consensus Report of the Sixth European Workshop on Periodontology. Tonetti MS, Hammerle CH. Seite / Page 16 14 Acta Biomater, 2008 Effect of surface structure on protein adsorption to biphasic calcium-phosphate ceramics in vitro and in vivo. Zhu XD, Fan HS, Xiao YM, Li DX, Zhang HJ, Luxbacher T, Zhang XD. Seite / Page 16 15 J Mater Sci Mater Med, 2008;19:2819-25 Preparation and characterization of biphasic calcium phosphate ceramics of desired composition. Zyman ZZ, Tkachenko MV, Polevodin DV. Seite / Page 17

9


ossceram 16 Int J Oral Maxillofac Implants, 2007;22 Suppl:49-70 Which hard tissue augmentation techniques are the most successful in furnishing bony support for im plant placement? Aghaloo TL, Moy PK. Seite / Page 17 17 Clin Implant Dent Relat Res, 2007;9:166-77 A literature review on biomaterials in sinus augmentation procedures. Browaeys H, Bouvry P, De Bruyn H. Seite / Page 17 18 Nanosci Nanotechnol, 2007;7:808-13 Surface structural biomimetics and the osteoinduction of calcium phosphate biomaterials. Fan H, Ikoma T, Tanaka J, Zhang X. Seite / Page 18 19 J Mater Sci Mater Med, 2007;18:287-94 Inflammatory reaction in rats muscle after implantation of biphasic calcium phosphate micro particles. Fellah BH, Josselin N, Chappard D, Weiss P, Layrolle P. Seite / Page 18 20 Clin Oral Implants Res, 2007;18:752-60 Evaluation of a novel biphasic calcium phosphate in standardized bone defects: a histologic and histomorphometric study in the mandibles of minipigs. Jensen SS, Yeo A, Dard M, Hunziker E, Schenk R, Buser D. Seite / Page 18 21 J Periodontol, 2007;78:377-96 Bone augmentation techniques. McAllister BS, Haghighat K. Seite / Page 19 22 Swed Dent J Suppl, 2007:7-66 Long time follow up of implant therapy and treatment of peri-implantitis. Roos-Jansaker AM. Seite / Page 19 23 Folia Morphol (Warsz), 2006;65:63-5 The ultrastructure and processing properties of Straumann Bone Ceramic and NanoBone. Dietze S, Bayerlein T, Proff P, Hoffmann A, Gedrange T. Seite / Page 20 24 Int J Oral Maxillofac Implants, 2006;21:696-710 The efficacy of various bone augmentation procedures for dental implants: a Cochrane systematic review of randomized controlled clinical trials.

10

Krekmanov L. Seite / Page 20 25 J Biomed Mater Res A, 2006;77:747-62 Osteoinduction by biomaterials--physicochemical and structural influences. Habibovic P, Sees TM, van den Doel MA, van Blitterswijk CA, de Groot K. Seite / Page 20 26 Final rule. Fed Regist, 2005;70:21947-50 Dental devices; reclassification of tricalcium phosphate granules and classifi-cation of other bone grafting material for dental bone repair. Seite / Page 21 27 Biomaterials, 2005;26:5313-20 The inflammatory potential of biphasic calcium phosphate granules in osteoblast/macrophage co-culture. Curran JM, Gallagher JA, Hunt JA. Seite / Page 21 28 J Biomed Mater Res B Appl Biomater, 2005;74:636-42 Quantitative evaluation of the fibrin clot extension on different implant surfaces: an in vitro study. Di Iorio D, Traini T, Degidi M, Caputi S, Neugebauer J, Piattelli A. Seite / Page 21 29 J Biomed Mater Res B Appl Biomater, 2005;74:448-57 Maxillary sinus augmentation with Bio-Oss particles: a light, scanning, and transmission electron microscopy study in man. Orsini G, Traini T, Scarano A, Degidi M, Perrotti V, Piccirilli M, Piattelli A. Seite / Page 21 30 Int J Periodontics Restorative Dent, 2004;24:565-77 Systematic review of survival rates for implants placed in the grafted maxillary sinus. Del Fabbro M, Testori T, Francetti L, Weinstein R. Seite / Page 22 31 J Mater Sci Mater Med, 2003;14:195-200 Current state of the art of biphasic calcium phosphate bioceramics. Daculsi G, Laboux O, Malard O, Weiss P. Seite / Page 22 32 J Mater Sci Mater Med, 2003;14:201-9 Biphasic calcium phosphate bioceramics: preparation, properties and applications. LeGeros RZ, Lin S, Rohanizadeh R, Mijares D, LeGeros JP. Seite / Page 22

Tel. (+49) 0 73 09 / 8 72-6 00 | Fax (+49) 0 73 09 / 8 72-6 35 | www.bredent-medical.com | e-mail info-medical@bredent.com


33 Ann Periodontol, 2003;8:328-43 Effect of maxillary sinus augmentation on the survival of endosseous dental implants. A systematic review. Wallace SS, Froum SJ. Seite / Page 23 34 J Clin Periodontol, 2002;29 Suppl 3:226-31; discussion 232-3 A systematic review of the survival of implants in bone sites augmented with barrier membranes (guided bone regeneration) in partially edentulous patients. Hammerle CH, Jung RE, Feloutzis A. Seite / Page 23 35 J Biomed Mater Res, 2002;63:115-21 Degradation characteristics of alpha and beta tri-calcium-phosphate (TCP) in minipigs. Wiltfang J, Merten HA, Schlegel KA, Schultze-Mosgau S, Kloss FR, Rupprecht S, Kessler P. Seite / Page 24 36 J Mater Sci Mater Med, 2003;14:195-200 Influence of dosage on cell biocompatibility of hydroxyapatite/tricalcium phos-phate. Zhang Z, Lu XF, Wang ZM, Lu B, Cheng JQ, Li YP. Seite / Page 24 37 Clin Implant Dent Relat Res, 2001;3:87-96 Histologic analysis of clinical biopsies taken 6 months and 3 years after maxillary sinus floor aug mentation with 80% bovine hydroxyapatite and 20% autogenous bone mixed with fibrin glue. Hallman M, Lundgren S, Sennerby L. Seite / Page 24 38 J Mater Sci Mater Med, 2001;12:305-11 Hydroxyapatite spheres with controlled porosity for eye ball prosthesis: processing and characterization. Rivera-Munoz E, Diaz JR, Rogelio Rodriguez J, Brostow W, Castano VM. Seite / Page 25 39 Biomaterials, 2001;22:1599-606 Analysis of the risk of transmitting bovine spongiform encephalopathy through bone grafts derived from bovine bone. Wenz B, Oesch B, Horst M. Seite / Page 25

41 Adv Dent Res, 1999;13:99-119 In vivo bone response to biomechanical loading at the bone/dental-implant interface. Brunski JB. Seite / Page 26 42 J Mater Sci Mater Med, 1999;10:199-204 Elaboration conditions influence physicochemical properties and in vivo bioactivity of macroporous biphasic calcium phosphate ceramics. Gauthier O, Bouler JM, Aguado E, Legeros RZ, Pilet P, Daculsi G. Seite / Page 26 43 J Mater Sci Mater Med, 1999;10:111-20 Role of interconnections in porous bioceramics on bone recolonization in vitro and in vivo. Lu JX, Flautre B, Anselme K, Hardouin P, Gallur A, Descamps M, Thierry B. Seite / Page 26 44 Gerodontology, 1998;15:25-34 Age changes in bone. Boyde A, Kingsmill VJ. Seite / Page 27 45 Clin Oral Implants Res, 1998;9:137-50 Evaluation of filling materials in membrane-protected bone defects. A comparative histomor phometric study in the mandible of miniature pigs. Buser D, Hoffmann B, Bernard JP, Lussi A, Mettler D, Schenk RK. Seite / Page 27 46 Int J Prosthodont, 1998;11:391-401 Mechanisms of endosseous integration. Davies JE. Seite / Page 27 47 Int J Oral Maxillofac Implants, 1998;13 Suppl:11-45 Report of the Sinus Consensus Conference of 1996. Jensen OT, Shulman LB, Block MS, Iacono VJ. Seite / Page 27 48 Anat Rec, 1996;245:426-45 In vitro modeling of the bone/implant interface. Davies JE. Seite / Page 28

40 Biomaterials, 2001;22:2617-23 Material-dependent bone induction by calcium phosphate ceramics: a 2.5-year study in dog. Yuan H, Yang Z, De Bruij JD, De Groot K, Zhang X. Seite / Page 25

11


ossceram 1. J Orthop Res, 2009;27:155-61 Subcutaneous-induced membranes have no osteoinductive effect on mac-roporous HA-TCP in vivo. Catros S, Zwetyenga N, Bareille R, Brouillaud B, Renard M, Amedee J, Fricain JC. Summary: Induced Membranes Technique was first described to enhance bone reconstruction of large osseous defects. Previous in vitro studies established their osteoin pose of this study was to test in vivo the osteoinductive properties of induced membranes on a macroporous HA-TCP in a nonosseous subcutaneous site. Sub-cutaneous-induced membranes were obtained in 21 rabbits; 1 month later, the membranes were filled with a biphasic calcium phosphat and immunohistochemical studies were per-formed on membrane biopsies. Undecalcified and decalcified sections were qualitatively and quantitatively analyzed. (45)Ca uptake was observed and quantified on the sections using microimager analysis. Dense vascularity was found in the induced membranes. New bone formation was detected in the HA-TCP + autograft samples and increased significantly from 3 to 6 months (p < 0.05). No placed in a nonosseous site have no osteoinductive properties on a macroporous bi-phasic calcium phosphate biomaterial. 2. J Biomed Mater Res B Appl Biomater, 2009;88:611-8 Micro-computed tomographic analysis of bone healing subsequent to graft placement. Chopra PM, Johnson M, Nagy TR, Lemons JE. Summary: A micro-computed tomographic (muCT) analysis of bone healing subsequent to graft (tri calcium phosphate/TCP) placement in the maxillary sinus prior to dental endosteal implant placement was the focus of the current study. Ten trephined rod shaped human bone cores were obtained three months after the placement of particulate graft material. Using the muCT, samples were evaluated at 6 and 20 mum resolutions. The images exhibited regions of different grey scale (GL) magnitudes for bone and graft allowing a differentiation and quantification of the two sample regions. The GL threshold magnitudes at 20 mum resolution were determined to be less than 235 for or-ganic and fluid, 235-450 for bone, 400600 for bone ity of the TCP material, the mean bone volume was 25.50 (11.28) ranging from 5.66 to 37.9 and the mean graft volume was 0.42 (0.37) ranging from 0.01 to 1.17. The mean graft to bone volume ratio was 0.015 (0.01) with a range from 0.002 to 0.024. The structural data and observations from two- and anatomy of the TCP grafting b implant treatments. 3. J Med Microbiol, 2009;58:132-7 Influence of surface porosity and pH on bacterial adherence to hydroxyapatite and biphasic calcium phosphate bioceramics. Kinnari TJ, Esteban J, Martin-de-Hijas NZ, Sanchez-Munoz O, Sanchez-Salcedo S, Colilla M, Vallet-Regi M, Gomez-Barrena E Summary: Hydroxyapat osteoconductive structure. Their porosity and the lowering of surrounding pH as a result of surgical trauma may, however, predispose these materials to bacterial infections. For this reason, the influence of porosity and pH on the adherence of common Gram-positive bacteria to the surfaces of t both bioce 200 nm. Moreover, total porosity was 20 % for HA and 50 % for BCP. Adherence of Staphylococcus aureus and Staphylococcus epi-dermidis was studied at a physiological pH of 7.4 and at a pH simulating bone infection of 6.8. Moreover, the effect of pH on the zeta potential of HA, BCP and o to HA and BCP surfaces decreased significantly, although at the same time the negative zeta-potential values of the ceramic surfaces and both . A decrease in pH to 6.8 pores sufficiently large to allow the internalization of staphylococci. Their anti-adherent properties seemed to improve when pH value decreased, suggesting that HA and BCP bioceramics are not compro-mised upon orthopaedic use.

12

Tel. (+49) 0 73 09 / 8 72-6 00 | Fax (+49) 0 73 09 / 8 72-6 35 | www.bredent-medical.com | e-mail info-medical@bredent.com


4. Clin Implant Dent Relat Res, 2009;11:41-51 Peri-implant bone organization under immediate loading conditions: collagen fiber orientation and mineral density analyses in the minipig model. Traini T, Neugebauer J, Thams U, Zoller JE, Caputi S, Piattelli A. Summary: BACKGROUND: Mechanical properties of bones are greatly influenced by percentages of organic and mineral constituents. Nevertheless, information about mineralization level on a microscopic scale and collagen fiber organization in peri-implant bone after immediate loading is scarce. PUR-POSE: The aim of this work was to analyze and compare the degree of miner-alization and collagen fiber orientation in alveolar bone (AB) and peri-implant bone of immediately loaded (IL) and unloaded (NL) implants. MATERIALS AND METHODS: A total of 25 dental implants of 3.8 mm in diameter and 11 mm in length were used in the present study. In five minipigs, three premolars and the first molar were removed from the left side of the mandible. Three months later, five implants for each animal were inserted. Four implants were loaded immediately with a fixed restoration, while one implant was left unloaded. After a 4-month healing period, all implants were retrieved. C implant and AB retrieved 5 mm from the implant. RESULTS: The bone/imp statistically significant (p = 0.554). In the peri-implant bone, the area related to transverse collagen fibers was 112,453 +/- 4,605 pixels for IL implants and 87,256 +/- 2,428 pixels for NL implants. In the AB, the area re-lated to transverse collagen fibers was 172,340 +/- 3,892 pixels. The differ-ence between groups was statistically significant (p < .001). The degree of mineralization of peri-implant bone was 137 +/- 19 gray level for IL implants and 115 +/- 24 gray level for NL implants, while in the AB, the degree of min-eralization was 125 +/- 26 gray level. This difference was statistically signifi-cant (p < .001). CONCLUSION: In this study, it was found that IL and NL im-plants showed the same degree of osseointegration. The bone matrix around IL implants had a higher quantity of transverse collagen fibers and presented a higher level of mineralization. 5. J Clin Periodontol, 2008;35:316-32 Surgical treatment of peri-implantitis. Claffey N, Clarke E, Polyzois I, Renvert S. Summary: OBJECTIVES: To review the literature on surgical treatment of peri-implantitis. MATERIAL AND METHODS: A search of Pu 2007 were included. RESULTS: A total of 43 studies were selected for the review. Only 13 of these were studies in humans and only one study directly addressed disease resolution. Thus the available evidence for surgical treatment of peri-implantitis is extremely limited. ANIMAL STUDIES: Re-osseointeg gration. No single surface decontamination method appears to be distinctly superior. Open debridement with surface decontamination can achieve resolution. HUMAN STUDIES: Access surge decontamination (chemical agents, air abrasives and lasers) was found to be superior. The use of regenerative procedures such as bone graft techniques with or without the use of barrier membranes has been reported with various degrees of success. However, it must be stressed that such techniques do not address disease resolution but rather merely attempt to fill the osseous defect. 6. Clin Oral Implants Res, 2008;19:796-803 Maxillary sinus grafting with Bio-Oss or Straumann Bone Ceramic: histomorphometric results from a randomized controlled multicenter clinical trial. Cordaro L, Bosshardt DD, Palattella P, Rao W, Serino G, Chiapasco M. Summary: INTRODUCTION: This investigation was designed to compare the histomorphometric results from sinus floor augmentation with anorganic bovine bone (ABB) and a new biphasic calcium phosphate, Straumann Bone Ceramic (BCP). MATERIALS AND METHODS: Forty-eight sinus augmentat

13


ossceram assigned to th tomorphometric region; (2) contact between the graft substitute material and new bone. RESULTS: Measurable biopsies were available from 56% of the test and 81.8% of the control sites. Histology showed close contact between new bone and graft particles for both groups, with no significant differences in the amount of mineralized bone (21.6+/-10.0% for BCP vs. 19.8+/-7.9% for ABB; P=0.53) in the biopsy treat-ment compartment of test and control site. The bone-to-graft contact was found to be significantly greater for ABB (48.2+/-12.9% vs. 34.0+/-14.0% for BCP). Significantly less remaining percentage of graft substitute material was found in the BCP group (26.6+/-5.2% vs. 37.7+/-8.5% for ABB; P=0.001), with more soft tissue components (46.4+/-7.7% vs. 40.4+/-7.3% for ABB; P=0.07). However, the amount of soft tissue components for both groups was found not to be greater than in the residual alveolar ridge. DISCUSSION: Both ABB an able for sinus a resorption characteristics of BCP requires further investigation. 7. Cochrane Database Syst Rev, 2008:CD003607 Interventions for replacing missing teeth: bone augmentation techniques for dental implant treatment. Esposito M, Grusovin MG, Kwan S, Worthington HV, Coulthard P. Summary: BACKGROUND: Dental implants require sufficient bone to be adequately stabilised. For some patients implant treatment would not be an option without bone augmentation. A variety of materials and surgical techniques are available for bone augmentation. OBJECTIVES: General objectives: To test the null hypothesis of no difference in the success, function, morbidity and patient satisfaction between different bone augmentation techniques for dental implant treatment. Specific objectives: (A) to test whether and when augmentation procedures are necessary; (B) to test which is the most effective augmentation technique for specific clinical indications. Trials were divided into three broad categories accor (2) implants placed in extraction sockets; (3) fenestrated implants. SEARCH STRATEGY: The Cochrane Oral Health Group‘s Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE were searched. Severa More than 55 implant manufacturing companies were also contacted. Last electronic search was conducted on 9th January 2008. SELECTION CRITERIA: Randomised controlled trials (RCTs) of different techniques and materials for augmenting bone for implant treatment reporting the outcome of implant therapy at least to abutment connection. DATA COLLECTION AND ANALYSIS: Screening of in duplicat for continuous outcomes and odd ratios for dichotomous outcomes with 95% confidence intervals. The statistical unit of the analysis was the patient. MAIN RESULTS: Seventeen RCT niques were evaluated in different trials, no meta-analysis could be performed. Ten trials evaluated different techniques for vertical or horizontal bone aug-men trials evaluated different techniques to treat bone dehiscence or fenestrations around implants. AU-THORS‘ CONCLUSIONS: Major bone grafting procedures of resorbed mandi-bles may not be justified. Bone substitutes (Bio-Oss or Cerasorb) may replace autogenous bone for sinus lift procedures of atrophic maxillary sinuses. Vari-ous techniques can augment bone horizontally and vertically, but it is unclear which is the most efficient. It is unclear whether augmentation procedures at immediate single implants placed in fresh extraction sockets are needed, and which is the most effective augmentation procedure, however, sites treated with barrier plus Bio-Oss showed a higher position of the gingival margin when compared to sites treated with barriers alone. Non-resorbable barriers at fen-estrated implants regenerated more bone than no barriers, however it remains unclear whether such bone is of benefit to the patient. It is unclear which is the most effective technique for a Bio-Oss. Titanium may be preferable to resorbable screws to fix-ate onlay bone grafts. The use of particulate autogenous bone from intraoral locations, also taken with dedicated aspirators, might be associated with an increased risk of infective complications. These findings are based on few tri-als including few patients, sometimes having short follow up, and often being judged to be at high risk of bias. 8. Biomaterials, 2008;29:1177-88 Osteogenicity of biphasic calcium phosphate ceramics and bone autograft in a goat model. Fellah BH, Gauthier O, Weiss P, Chappard D, Layrolle P. Summary: The aim of topic sites. Biphasic calcium phosphate (BCP) granules composed of hydroxyapatite (HA) and beta-tricalcium phosphate (beta-TCP) in a 60/40 ratio were sintered at 1050, 1125 and 1200 degrees C, producing different microporosities. Either BCP ceramic granules or autologous bone

14

Tel. (+49) 0 73 09 / 8 72-6 00 | Fax (+49) 0 73 09 / 8 72-6 35 | www.bredent-medical.com | e-mail info-medical@bredent.com


chips (n=7) we 6 or 12 weeks in the ectopic sites. Hollow and bored polytetrafluoroethylene (PTFE) cylinders were filled with autologous bone, BCP granules or left empty, then i not minerali with the BCP1050 and BCP1125 granules in the femoral sites after 6 weeks. The amount of bone after 12 weeks was 5.6+/-7.3 and 9.6+/-6.6% for BCP1050 and BCP1125, respectively. Very little bone forma-tion was observed with the BCP1200 implants (1.5+/-1.3% at 12 weeks). In both the ectopic and study shows that bone defects. 9. A pilot study. Int J Periodontics Restorative Dent, 2008;28:273-81 cal assessment of vital bone formation.

-

Froum SJ, Wallace SS, Cho SC, Elian N, Tarnow DP. Summary: This blinded, randomized, controlled pilot investigation is the first to histomorphometrically compare vital bone formation following bilateral sinus gra 8 months following graft placement. Twelve patients were selected. Following elevation of the lateral sinus walls, one material was placed in the right sinu same time fr obtained from 21 healed sinuses in 12 patients. Nine patients provided bilateral cores. Histomorphometric analysis of 10 BCP cores and 11 ABBM cores revealed an average vital bone content of 28.35% and 22.27%, respectively. The average percentage of residual graft particles was 28.4% in the BCP cores and 26.0% in the ABBM cores. The difference in vital bone formation was not significantly different (n = 9 patients, paired t test) be-tween bilateral sinuses treated with the BCP and those treated with the ABBM. Histologically, both materials appeared to be osteoconductive and support new bone formation. Future studies are needed to confirm the ability of this regenerated bone to support dental implant maintenance over time. 10. J Biomed Mater Res B Appl Biomater, 2008 Comparative study of biphasic calcium phosphates with different HA/TCP ratios in mandibular bone defects. A long-term histomorphometric study in minipigs. Jensen SS, Bornstein MM, Dard M, Bosshardt DD, Buser D. Summary: Three biphasic calcium phosphate (BCP) bone substitute materials with hydroxyapatite (HA)/tricalcium phosphate (TCP) ratios of 20/80, 60/40, and 80 bone defect 13, 26, and 52 weeks, respectively. The histologic and histomorphometric evaluation focused on dif-ferences in amount and pattern of bone formation, filler degradation, and the interface between bone and filler. Collapse of the expanded polytetrafluoro-ethylene barrier membrane into the coagulum defects underlined the necessity of a filler material to maintain the augmented volume. Quantitatively, BCP 20/80 showed bone formation and degradation of the filler material similar to autografts, whereas BCP 60/40 and BCP 80/20 rather equaled DBBM. Among the three BCP‘s, the amount of bone formation and degradation of filler mate-rial seemed to be inversely proportional to the HA/TCP ratio. The fraction of filler early healing phase. TRAP-positive multinucleated cells were identified on BCP and DBBM surfaces without showing typical signs of resorption lacunae. (c) 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009. 11. Clin Oral Implants Res, 2008;19:539-45 Effect of platelet-rich plasma on bone regeneration in dentistry: a systematic review. Plachokova AS, Nikolidakis D, Mulder J, Jansen JA, Creugers NH. Summary: OBJECTIVE: To review systematically the reported effects of platelet-rich plasma (PRP) on bone regeneration. MATERIAL AND METHODS: Up to June 20 ‚dentistry‘ and their PRP (test) or without PRP (control), including at least five patients with a follow-up period of more than 3 months and using clinical assessment, radiography, histo out independently by two readers. RESULTS: The literature search revealed 108 references, of which 17 were selected for further analysis. Finally, nine articles fulfilling the inclusion criteria were selected for systematically review. Owing the substantial heterogeneity of the studies it was not possible to analyze the data statistically. An attempt was made to compare results from studies that used similar outcome measures by calculating and adding confidence intervals to the

15


ossceram data presented in significant (ranging from 0.8 to 3.2 mm). The reported effects of PRP in sinus elevation (compared with their controls) were <10%. CONCLUSION: We found evidence for beneficial effects of PRP in the treatment of periodontal defects. Evidence for beneficial effects of PRP in sinus elevation appeared to be weak. No conclusions can be drawn about other applications of PRP in dentistry. 12. Acta Biomater, 2008 Calcium phosphate-based particles influence osteogenic maturation of human mesenchymal stem cells. Saldana L, Sanchez-Salcedo S, Izquierdo-Barba I, Bensiamar F, Munuera L, Vallet-Regi M, Vilaboa N. Summary: Biphasic cal or additives to which oblast phenotype. This study analyses the influence of BCP particles and their precursors, calcium-deficient apatite (CDA) particles, on in vitro hMSC behaviour. Both types of particles were efficiently internalized by hMSC. Cell viability, morphology and actin cytoskeleton reorganization were unaffec bone matrix mineralization to a lesser extent than CDA, as assayed by evaluation of alkaline phosphatase activity, osteopontin secretion and mineralized nodule formation. The ability of bioceramic particles to affect osteogenic maturation through modification of soluble factors in me-dia was assa teogeni ciency in its composition pre-vented Ca(2+) uptake, allowing the development of a functional osteoblast phenotype. 13. J Clin Periodontol, 2008;35:168-72 Advances in bone augmentation to enable dental implant placement: Consensus Report of the Sixth European Workshop on Periodontology. Tonetti MS, Hammerle CH. Summary: BACKGROUND: Bone augmentation procedures to enable dental implant placement are frequently performed in practice. METHODS: In this session the European Workshop on Periodontology discussed the evidence in support of the procedures and examined both adverse events and implant the conclusions that could be drawn were limited by elements of design and/or reporting that are amenable to improvement. RESULTS: With regar nized the potential these data to a wider array of operators and clinical settings. With regards to sinus floor augmentation, perforation of the sinus membrane, graft infection and graft loss resulting in inability of implant placement were the major reported adverse events. In cases with <6 mm of residual bone height, 17% of subjects experienced implant loss in the first 3 years following lateral window augmentation. After trans-alveolar sinus floor augmentation 11% of subjects experienced implant loss over 3 years. Significant research activity (both pre-clinical and clinical) was identified in the area of growth factors-induced bone augmentation. Initial clinical trials support the potential of BMP-2. CONCLUSIONS: Clinically, the consensus highlighted that bone augmentation procedures can fail and that implants placed in these areas do not necessarily enjoy the questions on: (i augmented or pristine sites; and (iii) the clinical benefits of bone augmentation with respect to alternative treatments. 14. Acta Biomater, 2008 Effect of surface structure on protein adsorption to biphasic calcium-phosphate ceramics in vitro and in vivo. Zhu XD, Fan HS, Xiao YM, Li DX, Zhang HJ, Luxbacher T, Zhang XD. Summary: Protein adsorptio rials determine the behavior of protein adsorption. In the present study, two biphasic calcium-phosphate ceramics (BCPs) with different surface structures wer protein adsorption on them was investigated. Porous BCP showed higher ability to adsorb proteins, and transforming growth factor-beta1 (TGFbeta1) adsorption notably increased with increasing in vivo implantation time. The strong affinity of BCP to TGF-beta1 might provide important information for exploring the mechanism of the osteoinduction of calcium phosphates.

16

Tel. (+49) 0 73 09 / 8 72-6 00 | Fax (+49) 0 73 09 / 8 72-6 35 | www.bredent-medical.com | e-mail info-medical@bredent.com


15. J Mater Sci Mater Med, 2008;19:2819-25 Preparation and characterization of biphasic calcium phosphate ceramics of desired composition. Zyman ZZ, Tkachenko MV, Polevodin DV. Summary: A modifie composition (hydroxyapatite (HA)/beta-tricalcium phosphate (beta-TCP) ratio) has been developed. The principal idea of the route was combining a precipitation and a solid phase methods. First, a nonstoichiometric (slightly carbonated calcium-deficient) HA (CdHA) precipitate was synthesized b to the amount resulting in a stoichiometric HA) under definite conditions, and a powder of the precipitate was prepared and calcinated in air (860 degrees C, 1.5 h). In the second stage, a BCP ceramics of the composition determined by the calcium-deficiency in a calcinated powder (the acid abund degrees C, 2h). A calibrating dependence of the HA/beta-TCP ratio in the ceramics on the acid abundance has been plotted which enabled a controlled pr BCP materials was found. Using the correlation, the process of CdHA --> beta-TCP transformation could be easily monitored. The density and micro-hardness of the BCP ceramics neglectly depended on the composition, how-ever, the compressive strength did: the lower the HA/beta-TCP ratio, the higher the strength in the dense materials. 16. Int J Oral Maxillofac Implants, 2007;22 Suppl:49-70 Which hard tissue augmentation techniques are the most successful in furnishing bony support for implant placement? Aghaloo TL, Moy PK. Summary: PURPOSE: A variety of tec of this systemat support long-term survival. METHODS: A system and 200 2 anatomic site identified and categorized, including guided bone regeneration (GBR), onlay/veneer grafting (OVG), combinations of onlay, veneer, interpositional inlay grafting (COG lar in-terpositional grafting (MI), and socket preservation (SP). All identified articles were evaluated and screened by 2 independent reviewers to meet strict inc ed a total of 526 ar titles cient data for extraction and analysis. RESULTS: For the maxill 102 month allogeneic/nonautogenous composite grafts, 81% for implants placed into alloplast and alloplast/xenograft materials, and 95.6% for implants placed into xenog 74 months. The implant survival rate was 95.5% for GBR, 90.4% for OVG, 94.7% for DO, and 83.8% for COG. Other techniques, such as DD, RS, SP, and MI, were difficult to analyze because of the small sample size and data heteroge-neity within and across studies. CONCLUSIONS: The maxilla placed, regardless of graft material(s) used, compares favorably to implants placed conventionally, with no grafting procedure, as reported in other systematic reviews. Alveolar ridge augmenta-tion techniques do not have detailed documentation or long-term follow-up studies, with the exception of GBR. However, studies that met the inclusion criteria seemed to be comparable and yielded favorable results in supporting dental implants. The function of resi provide fur-ther insight into augmentation procedures to support dental implant survival. 17. Clin Implant Dent Relat Res, 2007;9:166-77 A literature review on biomaterials in sinus augmentation procedures. Browaeys H, Bouvry P, De Bruyn H. Summary: BACKGROUND: Sinus augme Although the pat

17


ossceram the grafting procedure. PURPOSE: The overall objective of this review was to assess the efficacy of different graft materials used in sinus augmentation procedures as demonstrated in animal studies. MATERIALS AND METHODS: A specific a 1995 and 2004 and kept updated until 2006. RESULTS: Twenty-six tomorphometric follow-up, and lack of specific integration or loading period, a comparison of the studies and the biomaterials used was dif-ficult. CONCLUSIONS: In general, a highly osteoconductive and less dependent on sinus floor endosteal bone migration. The addition of bovine bone mineral to autogenous bone can be beneficial for graft success because it acts as a slowly resorbing space maintainer. Porous hydroxyapatite is suitable when mixed with autogenou demineralized based on hist 18. J Nanosci Nanotechnol, 2007;7:808-13 Surface structural biomimetics and the osteoinduction of calcium phosphate biomaterials. Fan H, Ikoma T, Tanaka J, Zhang X. Summary: From the point of function. T cal functions. To process. In this study, the porous biphasic calcium phosphate (BCP) ceramic was used to study the relationship of surface micro/nano structure and the biological function of osteoinductivity. Surface structural biomimetic was achieved by a soft technology of surface treating with simulated body fluid (SBF) or SBF containing protein molecules (BSA-SBF). The biological function of osteoinduction was tested by studying the bone form re-construct the surface charthe protein molecules and showed higher osteoinductivity. The study gave the evidence of material sur-face structural biomimetic to promote biological function of biomaterials with certain biological function. 19. J Mater Sci Mater Med, 2007;18:287-94 Inflammatory reaction in rats muscle after implantation of biphasic calcium phosphate micro particles. Fellah BH, Josselin N, Chappard D, Weiss P, Layrolle P. Summary: Several s vestigating the inflammatory response towards biphasic calcium phosphate (BCP) ceramic micro particles. BCP composed of hydroxyapatite (HA) and beta-tricalcium phosphate, HA/beta -TCP ratio of 50/50, were prepared by sintering at 1200 degrees C for 5 h. After crushing, 3 fractions of BCP micro pa (XRD), scanning electron microscopy (SEM) and laser scattering. The inflammatory reactions induced by BCP micro particles implanted in quadriceps muscles of rats for 7, 14 and 21 days were studied by histology (n = 8/group). A fibrous tissue encapsulation of the BCP micro particles implanted in muscle tissue was observed and fibrosis was similar for the 3 groups of micro particles. The comparison of the cellular response indicated that the total number of cells was significantly higher for BCP < 20 micro m than for 40-80 and 80-200 micro m (p < 0.0001). The number of macrophages was relatively higher for the smallest than for the intermediate and largest fractions (p < 0.0001). The relative percentage of giant cell for the 3 fractions and after the 3 delays. Therefore, the BCP micro particles < 20 micro m initiated an inflammatory response which might play an important role in osteogenesis. 20. Clin Oral Implants Res, 2007;18:752-60 Evaluation of a novel biphasic calcium phosphate in standardized bone defects: a histologic and histomorphometric study in the mandibles of minipigs. Jensen SS, Yeo A, Dard M, Hunziker E, Schenk R, Buser D. Summary: OBJECTIVE: A novel biphasic calcium phosphate (CaP) granulate consisting of hydroxyapatite (HA) and beta-tricalciumphosphate (TCP) was compared with

18

Tel. (+49) 0 73 09 / 8 72-6 00 | Fax (+49) 0 73 09 / 8 72-6 35 | www.bredent-medical.com | e-mail info-medical@bredent.com


pure HA and pure TCP and with autograft as positive control. MATERIALS AND METHODS: Four s CP (60% : 40%), or TCP. Histologic and histomorphometric analysis of bone formation and graft degradation followed healing periods of 2, 4, 8, and 24 weeks. RESULTS: 2 weeks: more bone formation in defects filled with autograft than with the three CaP materials (P<0.05). 4 weeks: bone formation differed significantly (P<0.05) between all four materials (autograft>TCP>HA/TCP>HA). 8 weeks: more bone formation in defects with autograft and TCP than with HA/TCP (P<0.05), and HA/TCP had more bone formation than HA (P<0.05). 24 weeks: no difference in bone formation between the groups. Autograft and TCP resorbed quickly and almost com-pletely over 8 weeks, whereas HA/TCP and HA showed limited degradation over 24 weeks. CONCLUSIO bone formation corresponded to the content of TCP in the CaP materials. 21. J Periodontol, 2007;78:377-96 Bone augmentation techniques. McAllister BS, Haghighat K. Summary: BACKGROUND: The advent of o restoration of part such as infect driven dental implant therapy, reconstruction of the alveolar bone through a variety of regenerative surgical procedures has become predictable; it may be neces prognosis METHODS: A broad overview of the published findings in the English literature related to various bone augmentation techniques is outlined. A comprehensive comp with non-peer-reviewed articles eliminated as much as possible. RESULTS: The techniqu substitutes, genesis. CONCLUSIONS: Many diff c procedures to being developed for bone augmentation cases. 22. Swed Dent J Suppl, 2007:7-66 Long time follow up of implant therapy and treatment of peri-implantitis. Roos-Jansaker AM. Summary: Dental implant . Until recently few reports incl infections a ing number of patients have had their implants for a long time (>10 years). Data on treatment of peri-implant le-sions are scarce leaving the clinician with of peri-implant specific charact Studies I-III in-cluded 218 patients and 1057 implants followed for 9-14 years evaluating prevalence of, and factors related to implant loss (Paper I) and prevalence of peri-implant infections and related factors (Paper I-III). Study IV is a review describing different treatment modalities of peri-implant i with or withou combination implants are hig at remain-ing teeth before implant placement. (Paper I) Peri-implantitis is a common clinical entity after 9-14 years. (Paper II) Using the implant as the statistic was used as a statistical unit a history of periodontitis and smoking were explanatory for peri-implantitis. (Pa-per III) Animal research has demonstrated that re-osseointegration can occur. The majority of human studies were found to be case reports. Using sub-merged healing and bone transplants, bone fill can occur in peri-implant de-fects. (Paper IV) Surgical treatment of peri-implantitis using a bone substitute with or without a resorbable membrane resulted in similar pocket depth reduc-tion, attachment gain and defect fill. (Paper V) Bone substitute in combination with a resorbable membrane and a submerged healing resulted in defect fill > or =2 threads (1.2 mm) in 81% of the implants. (Paper

19


ossceram VI) In conclusion: 9-14 years after implant installation peri-implant lesions are a common clinical en-tity. Smokers and patients with a history of periodontal disease are at higher risk to develop peri-implantitis. Clinical improvements and defect fill can be ob-tained with various surgical techniques using a bone substitute. 23. Folia Morphol (Warsz), 2006;65:63-5 The ultrastructure and processing properties of Straumann Bone Ceramic and NanoBone. Dietze S, Bayerlein T, Proff P, Hoffmann A, Gedrange T. Summary: The ultrastructure, fundamental chemistry, and processing modes of fully synthetic bone grafting materials are relevant to the reconstruction of osseous defects. Rapid progress in the profitable market of biomaterials has led to the development of various bone substitutes. Despite all these efforts, an i Bone Cer with well-vascularised bone. 24. Int J Oral Maxillofac Implants, 2006;21:696-710 The efficacy of various bone augmentation procedures for dental implants: a Cochrane systematic review of randomized controlled clinical trials. Krekmanov L. Summary: PURPOSE: To test (a cific clinical indications. Trials were divided into 3 categories: (1) major vertical or horizontal bone augmentation (or both); (2) implants placed in extraction sockets; (3) fenestrated implants. MATERIALS AND METHODS: An exhaustive search was conducted for all randomized controlled clinical trials (RCTs) comparing different techniques and materials for augmenting b applied. The last electronic search was conducted on October 1, 2005. RESULTS: Thirteen RCTs of 30 for vertical an and 3 trials evaluated techniques to treat fenestrated implants. CONCLUSIONS: Major bone grafting procedures of extremely resorbed mandibles may not be justified. Bone substitutes may replace autogenous bone for sinus lift procedure bone vertically, but it is unclear which is the most efficient. It is unclear whether augmentation procedures are needed at imme-diate single implants placed in fresh extraction sockets; however, sites treated with barrier + Bio-Oss showed a higher position of the gingival margin than sites treated however, it remains unclear whether such bone is of benefit to the patient. Bone morpho-genetic proteins may enhance bone formation around implants grafted with Bio-Oss, but there was no reliable evidence supporting the efficacy of other active agents, such as platelet-rich plasma, in conjunction with implant treat-ment. 25. J Biomed Mater Res A, 2006;77:747-62 Osteoinduction by biomaterials--physicochemical and structural influences. Habibovic P, Sees TM, van den Doel MA, van Blitterswijk CA, de Groot K. Summary: Osteoinducti phenomenon is, however, still largely unknown. This in vivo study in goats was performed to get insight into processes governing the phenomenon of osteoinduction by biomaterials and had four main goals: (i) to further inves-tigate the influence of physicochemical properties and structure on biomaterial osteoinductive potential, (ii) to investigate the influence of implant size on the amount of induced bone, (iii) to investigate implantati implantati bonated apatite ceramic, indicated that, for a maximal osteoinductive potential, there is an optimal specific surface area for each material type. It was further shown that a decrease of the implant size with a half significantly decreased the relative amount of induced bone. In addition, subcutaneo muscularly. Ana specific surface area leads to more surface reactivity, which is hypothesized to be essential for osteoinductivity by bioma-terials.

20

Tel. (+49) 0 73 09 / 8 72-6 00 | Fax (+49) 0 73 09 / 8 72-6 35 | www.bredent-medical.com | e-mail info-medical@bredent.com


26. Final rule. Fed Regist, 2005;70:21947-50 Dental devices; reclassification of tricalcium phosphate granules and classifi-cation of other bone grafting material for dental bone repair. Summary: The Food and Drug Administration (FDA) is reclassifying tricalcium phosphate (TCP) granules for dental bone repair from class III to class II (special controls), classifying into class II (special controls) other bone grafting material for dental indications, and revising the classification name and identification of the device type. Bone grafting materials that contain a drug that is a therapeutic biologic will remain in class III and continue to require a premarket approval application. The classification identification includes materials such as hydroxyapatite, tricalcium phosphate, polylactic and polyglycolic acids, or collagen. This action is being taken to establish sufficient regulatory controls that will provide reasonable assurance of the safety and effectiveness of these devices. Elsewhere in this issue of the Federal Register, FDA is announcing the availability of the guidance document that will serve as the special control for the class II devices. 27. Biomaterials, 2005;26:5313-20 The inflammatory potential of biphasic calcium phosphate granules in osteoblast/macrophage co-culture. Curran JM, Gallagher JA, Hunt JA. Summary: Some biological properties of a range of biphasic calcium phosphate (BCP) granules were quantified using a co-culture model of primary unstimulated human osteoblasts and macrophages. The BCP granules were classified in terms of diameter and the ratio of tricalcium phosphate (TCP) and macroph quantified by the assessment of viable cell adhesion to the substrate, using lactate dehydrogenase assay, and the production and release of the cytokines; interle cell adhesion on all BCP granules was significantly lower than the tissue culture polystyrene control. Higher content TCP materials, (80% and 100% TCP) did not support viable cell adhesion after 1 day, lower content TCP materials, (20% and 50% TCP) granules did support viable cell adhesion throughout the time period. The percentage content of TCP was a more significant factor than granule size within the test conditions at all time points. 28. J Biomed Mater Res B Appl Biomater, 2005;74:636-42 Quantitative evaluation of the fibrin clot extension on different implant surfaces: an in vitro study. Di Iorio D, Traini T, Degidi M, Caputi S, Neugebauer J, Piattelli A. Summary: The aim of the present study was a quantitative evaluation of the in vitro fibrin clot extension on different implant surfaces. Forty-five diskshaped present study. For the quantitative evaluation of the fibrin clot, 30 specimens were used (10 per group); human whole blood was employed. Venous bloo time was 5 min at room temperature; then the samples were rinsed with saline solution and fixed in a buffered solution of glutaraldehyde and paraforma were observed under SEM at a magnification of 1000x. From each sample, 50 random micrographs were collected in .tif format with an N x M 1024 x 768 grid of pixels. Quantitative analysis of fibrin clot extension showed the following results: in machined samples fibrin clot extension was 345987.2 +/- 63747.7 pixels(2) (mean +/- SD), in DPS samples fibrin clot extension was 375930.9 +/- 54726.86 pixels(2) (mean +/- SD), and in Plus samples, fibrin clot extension was 612333.6 +/- 46268.42 pixels(2) (mean +/- SD). With ANOVA it was possible to find that there were significant differences among the groups. The Tukey test revealed that the extension of the fibrin clot of Plus samples was statistically higher com surface morphology and fibrin clot extension. Improvement in surface micro-texture complexity seems to determine the formation of a more extensive and three dimensionally complex fibrin scaffold. Further investigations are neces-sary to explain in more detail the mechanisms that regulate the fibrin clot for-mation on different implant surfaces. 29. J Biomed Mater Res B Appl Biomater, 2005;74:448-57 Maxillary sinus augmentation with Bio-Oss particles: a light, scanning, and transmission electron microscopy study in man. Orsini G, Traini T, Scarano A, Degidi M, Perrotti V, Piccirilli M, Piattelli A. Summary: Biological in sterilized bo scannin procedures. Under light micros-copy, most of the particles were surrounded by newly formed bone, while in a few cases, at the interface of some

21


ossceram particles it was possible to observe marrow spaces and biological fluids. Under scanning electron microscopy, in most cases, the particle perimeter appeared lined by bone that was tightly adherent to the biomaterial surface. Transmission electron microscopy showed that the bone tissue around the biomaterial showed all the phases of the bone healing process. In some areas, randomly organized collagen fibers were present, while in other areas, newly formed compact bone was present. In the first bone lamella collagen fibers contacting the Bio-Oss surface were oriented at 243.73 +/ a statistically sig-nificant difference of 44.32 degrees (p < 0.001). In the same areas the inten-sity of gray value was 172.56 +/- 18.15 (mean +/- SD) near the biomaterial surface and 158.71 +/- 21.95 (mean +/- SD) in the other part of the lamella with an unstatistically significant difference of 13.79 (p = 0.071). At the bone-biomaterial interface there was also an electron-dense layer similar to cement lines. This layer had a variable morph do not interfer

30. Int J Periodontics Restorative Dent, 2004;24:565-77 Systematic review of survival rates for implants placed in the grafted maxillary sinus. Del Fabbro M, Testori T, Francetti L, Weinstein R. Summary: Based on a systematic review of the literature from 1986 to 2002, this study sought to determine the survival rate of root-form dental implants placed in the simultaneous of the most relevant journals. All relevant articles were screened according to specific inclusion criteria. Selected papers were reviewed for data extraction. The se for qualitative data an was 91.49%. The database included 6,913 implants placed in 2,046 subjects with loaded follow-up time ranging from 12 to 75 months. Implant survival was 87.70% with grafts of 100% autogenous bone, 94.88% when combining autogenous bone with various bone substitutes, and 95.98% with b 95.98%, respectively. Simultaneous and delayed procedures displayed similar survival rates of 92.17% and 92.93%, respectively. When implants are placed in gra as effective are needed to further validate the findings. 31. J Mater Sci Mater Med, 2003;14:195-200 Current state of the art of biphasic calcium phosphate bioceramics. Daculsi G, Laboux O, Malard O, Weiss P. Summary: We have developed 15 years ago, with the collaboration of Lynch, Nery, and LeGeros in the USA, a bioactive concept based on biphasic calcium phosphate (BCP) ceramics. The concept is determined by an optimum balance of the more stable phase of HA and more soluble TCP. The material is soluble and gradually dissolves in the body, seeding new bone formation as it releases calcium and phosphate ions into the biological medium. The bioac-tive concept based on the dissolution/transformation processes of HA and TCP has been applied to both Bulk, Coating and Injectable Biomaterial processes, crystal/proteins in-teractions, cells and tissue colonization, bone remodeling, finally contributing to the unique strength of such interfaces. An imp performance of BCP concept. This type of artificial bone used from a long time in preclinical and in clinical trial, revealed the effi-ciency for bone filling, performance for bone reconstruction and efficacy for bone ingrowth at the expense of the micro macroporous BCP bioceramics. 32. J Mater Sci Mater Med, 2003;14:201-9 Biphasic calcium phosphate bioceramics: preparation, properties and applications. LeGeros RZ, Lin S, Rohanizadeh R, Mijares D, LeGeros JP. Summary: Biphas hydroxyapatite (HA), Ca(10)(PO(4))(6)(OH)(2), and beta-tricalcium phosphate (beta-TCP), Ca(3)(PO(4))(2), of varying HA/beta-TCP ratios. BCP is obtained when a synthetic or biologic calcium-deficient apatite is sintered at temperatures at and above 700 degrees C. Calcium deficiency depends on TCP ratio is determined by the calcium deficiency of the unsintered apatite (the higher the deficiency, the lower the ra-tio) and the sintering temperature. Properties of BCP bioceramics relating to their medical applications include: macroporosity, microporosity, compressive strength, bioreactivity ( ity. Due to the preferential dissolution of the beta-TCP component, the bioreactiv-ity is inversely proportional to the HA/beta-TCP ratio. Hence, the bioreactivity of BCP bioceramics can be controlled by manipulating the composition (HA/beta-TCP ratio) and/or the crystallinity of the BCP. Currently, BC It is available in the form of par-ticulates, blocks, customized designs for specific applications and as an in-jectible biomaterial in a polymer

22

Tel. (+49) 0 73 09 / 8 72-6 00 | Fax (+49) 0 73 09 / 8 72-6 35 | www.bredent-medical.com | e-mail info-medical@bredent.com


carrier. BCP cer on

-

33. Ann Periodontol, 2003;8:328-43 Effect of maxillary sinus augmentation on the survival of endosseous dental implants. A systematic review. Wallace SS, Froum SJ. Summary: BACKGROUND: Grafting the floor of the maxillary sinus has become the most common surgical intervention for increasing alveolar bone height prior to the placement of endosseous dental implants in the posterior maxilla. Outcomes of this procedure may be affected by specific surgical techniques, simultaneous versus delayed implant placement, use of barrier membranes over the lateral window, selection of graft material, and the surface characte-ristics and the length and width of the implants. RATIONALE: The primary objective of this systematic review was to determine the efficacy of the sinus augmentation procedure and compare the results achieved with various surgical techniques, grafting materials, and implants. FOCUSED QUESTION: In patients requ in the non-grafted posterior maxilla? SEARCH PROTOCOL: MEDLINE, the Cochrane Oral Health Group Specialized Trials Register, and the Database of Abstracts and Reviews of Effectiveness were searched for articles pu Maxillofacial Implants, and the Inter-national Journal of Periodontics & Restorative Dentistry and the bibliographies of all relevant papers and review articles. In accepted for publication were available. SELECTION CRITE-RIA: INCLUSION CRITERIA: Hum survival, and published in English, regardless of the evidence level, were considered. EXCLUSION CRITERIA: Studies involvi supplied by the study authors were excluded. DATA COLLECTION AND ANALYSIS: Where adequa branes) were isolated and subjected to meta-regression, a form of meta-analysis. MAIN RESULTS: 1. Forty-three studies, 3 randomized controlled clinical trials (RCTs), 5 controlled trials (CTs), 12 case series (CS), and 23 retrospective analyses (RA) were identified. Thirty-four were lateral window interventions, 5 were osteotome interventions, 2 were lo-calized management of the sinus floor, and 2 involved the crestal core tech-nique. 2. Meta-regre graft material, and the use of a membrane over the lateral window. 3. The survival rate of implants placed in sinuses augmented with the lateral window tech-nique varied between 61.7% and 100%, with an average survival rate of 91.8%. For lateral window technique: 4. Implant survival rates reported i 5. Rough-s in sinuses aug survival rates were higher when a membrane was placed over the lateral window. 8. The utilization of grafts consisting of 100% autogenous bone or the incl ence between publication, and the evidence level of the study. REVIEWERS‘ CONCLUSIONS: Insufficient data were pre-sent to statistically evaluate the effects of smoking, residual crestal bone height, screw versus press-fit implant design, or the effect of implant surface micromorphology other than machined versus rough surfaces. There are insuf-ficient data to recommend the use of platelet-rich plasma in sinus graft sur-gery. 34. J Clin Periodontol, 2002;29 Suppl 3:226-31; discussion 232-3 A systematic review of the survival of implants in bone sites augmented with barrier membranes (guided bone regeneration) in partially edentulous patients. Hammerle CH, Jung RE, Feloutzis A. Summary: The aim regeneration ( least 1 porting mater in the respective study), absence of clinical implant mobility, absence of implant fracture, absence of progressive peri-implant crestal bone loss as assessed search and a hand search of relevant scientific journals were conducted including studies from the year 1990 to May 2001. A total of 11 stu-dies could be identified fulfilling the inclusion criteria. All studies except two had the characteristics of case series or cross-sectional surveys. The two dif-ferent studies had both test and control implants included in their analysis and qualified as controlled clinical trials. Cumulative success

23


ossceram or survival rates, re-spectively, for implants in regenerated bone ranged from 100% after 5 years to 79.4% after 5 years of function. Regarding survival data, no significant differ-ences were found in the controlled clinical trials between implants in regener-ated compared to implants in non-regenera sions can be 79% and 100% present sysaugmentation. 35. J Biomed Mater Res, 2002;63:115-21 Degradation characteristics of alpha and beta tri-calcium-phosphate (TCP) in minipigs. Wiltfang J, Merten HA, Schlegel KA, Schultze-Mosgau S, Kloss FR, Rupprecht S, Kessler P. Summary: In seven Goet filled with alpha-TCP or beta-TCP (tricalciumphosphate). ITI implants (Straumann, Freiburg, Germany) of 3.2 x 12-mm length were inserted into the underlying ceramic substitutes. Two additional pigs were used as control. Within the periods of observation (4, 16, 20, 28, 46, 68, and 86 weeks) fluorescent dyes were applied. Nondecalcified thin-sliced sections were examined by means of light and fluorescence microscopy. In addition mi the angiogenetic reossification pattern. Resorption was due to a hydrolytic and cellular degradation process. After 46 weeks histomorphological evaluation than 25%. After 86 weeks 95--97% of both alpha- and beta-TCP were resorbed. Ceramic residuals stayed within the newly formed trabeculae thus resisting further degradation until remodeling occurred. Both alpha- and beta-TCP show a comparable degradation process. At the 86-week postoperativ functional orientation. In comparison control defects showed only sparse reossification. The beta-TCP material shows an accelerated degradation mode and h classified as bone-rebuilding materials. 36. J Mater Sci Mater Med, 2003;14:195-200 Influence of dosage on cell biocompatibility of hydroxyapatite/tricalcium phos-phate. Zhang Z, Lu XF, Wang ZM, Lu B, Cheng JQ, Li YP. Summary: OBJECTIVE: To investigate the influence of different dose levels of hydroxyapatite/tricalcium phosphate (HA/TCP) on the proliferation and alkaline phosphatase (ALP) activity of rabbit osteoblasts. METHODS: Three different dose levels of HA/TCP (10%, 40%, 70%) were co-cultivated with rabbit osteoblasts respectively. The proliferation and ALP expression capacity of osteoblasts were examined with MTT method and enzyme histochemistry on-ce every normal control; polyvinylchloride as positive control; titanium alloy as negative control. RE-SULTS: There was remarkable time-effect relationship in the proliferation of osteoblasts. Ten percent HA/TCP did not affect osteoblasts growth while 40% HA/TCP coul co-cultivated with 70% HA/TCP. On the other hand, 10% HA/TCP could cause reversible dam-age on ALP activity of osteoblasts, whereas when th 0%, 40%, 70%) had no effect on the proliferation or ALP activity of osteoblasts. CONCLUSION: Dosage is an ed upon e 37. Clin Implant Dent Relat Res, 2001;3:87-96 Histologic analysis of clinical biopsies taken 6 months and 3 years after maxillary sinus floor augmentation with 80% bovine hydroxyapatite and 20% autogenous bone mixed with fibrin glue. Hallman M, Lundgren S, Sennerby L. Summary: BACKGROUND: Bovine hydroxyapatite (Bio-Oss, Geistlich Pharmaceutical, Wollhausen, Switzerland) has been suggested to be used in maxillary sinus floor augmentation procedures prior to or in conjunction with implant placement. However, the long-term histologic fate of this material is not well understood. P tite (BH), autogenous bone, and fibrin glue 6 months and 3 years after a maxillary sinus floor augmentation procedure. MATERIALS AND METHOD: Biopsies were taken from a group of 20 consecutive patients 6 months (n = 16) and 3 years (n = 12) after maxillary sinus floor augmentation with a mixture of BH (80%), autogenous bone (20%), and fibrin glue and prepared for histologic analysis. RESULTS: Light microscopy and morphomet

24

Tel. (+49) 0 73 09 / 8 72-6 00 | Fax (+49) 0 73 09 / 8 72-6 35 | www.bredent-medical.com | e-mail info-medical@bredent.com


+/- 12.6% nonmineralized tissue, followed by 21.2 +/- 24.5% lamellar bone, 14.5 +/- 10.3% BH particles, and 10.2 +/- 13.4% woven bone. The nonmineralize resorption o parti-cles. Afte The sur area occupied by BH particles, was 12.4 +/- 8.7% and had not changed from 6 months (not significant). Mo-reover, the sizes of the particles were simil +/- 28.8% after 3 years (p < .05). CONCLUSION: Histology of specimens from maxillary sinuses augmented with 80% BH particles, 20% autogenous bone, and fibrin glue showed a positive bone tissue response af-ter 6 months and 3 years after augmentation of the maxillary sinus floor prior to implant placement in a group fo 20 patients replaced by mature lamellar bone filling the interparti-cle space as observed in the 3-year specimens. Moreover, bone-integrated BH particles seem to be resi bone graft are available. 38. J Mater Sci Mater Med, 2001;12:305-11 Hydroxyapatite spheres with controlled porosity for eye ball prosthesis: processing and characterization. Rivera-Munoz E, Diaz JR, Rogelio Rodriguez J, Brostow W, Castano VM. Summary: Porous hydroxyapatite spheres were prepared by a modified gelcasting method producing a ceramic prosthesis with controled porosity. The spheres are approximately 2.2 cm in diameter with a relatively homogeneous pore size distribution from 10 to 40 microm in diameter. The samples wer both prior t microscopy (SEM), while surface area measurements were carried out by the BET technique. 39. Biomaterials, 2001;22:1599-606 Analysis of the risk of transmitting bovine spongiform encephalopathy through bone grafts derived from bovine bone. Wenz B, Oesch B, Horst M. Summary: Bone substitutes of bovine origin are widely used for treatment of bone defects in dental and orthopedic surgery. Due to the occurrence of BSE and the new varian Risk anal bone substitutes ( inactivation c these materials does not carry a risk of transmitting BSE to patients. 40. Biomaterials, 2001;22:2617-23 Material-dependent bone induction by calcium phosphate ceramics: a 2.5-year study in dog. Yuan H, Yang Z, De Bruij JD, De Groot K, Zhang X. Summary: Bone induction by different calcium phosphate biomaterials has been reported previously. With regard to (1) whether the induced bone would disappear with growth, a long-time investigation of porous hydroxyapatite ceramic (HA), porous biphasic calcium phosphate ceramic (TCP/HA, BCP), porous alpha-tricalcium phosphate ceramic (alpha-TCP) and porous beta-tricalcium phosphate ceramic (beta-TCP) was performed in dorsal muscles of dog, for 2.5 y on thin un-decalcified sections of retrieved samples. Normal compact bone with bone marrow was found in all HA implants (n = 4) and in all BCP implants (n = 4), 48 +/- 4% pore area was filled with bone in HA implants and 41 +/- 2% in BCP implants. Bo-ne-like tissue, which was a mineralised bone matrix with osteocytes but lacked osteoblasts and bone marrow, was found in all beta-TCP implants (n = 4) and in one of the four alpha-TCP implants. Both normal bone and bone-like tissues were confined inside the pores of the implants. The results show that calcium phosphate bone in both HA and BCP ceramics did neither disappear nor grow uncontrollably during the period as long as 2.5 years.

25


ossceram 41. Adv Dent Res, 1999;13:99-119 In vivo bone response to biomechanical loading at the bone/dental-implant interface. Brunski JB. Summary: Since dental ing would aid imp understanding implant loading as an aid to case planning. (2) At least for several months after surgery, bone healing in gaps between implant and bone as we environment. patite (HA). Since cement lines in normal bone have been identified as weak interfaces, a cement line at a bone-biomaterial inter-face may also be a weak point. tion early after implantation interferes with local bone healing and predisposes to a fibrous tissue interface instead of osseointegration. (5) Large strains interfacial overload physiology, re experiments, w bone (e.g., 42. J Mater Sci Mater Med, 1999;10:199-204 Elaboration conditions influence physicochemical properties and in vivo bioactivity of macroporous biphasic calcium phosphate ceramics. Gauthier O, Bouler JM, Aguado E, Legeros RZ, Pilet P, Daculsi G. Summary: Two different (HA) and beta-tricalcium phosphate (beta-TCP) powders, and BCP2 from calcination of a calcium-deficient apatite (CDA). The structural, physicochem MBCP2) imp showed that MBCP1 implants had a significantly higher degradation rate (P<0.0001) than MBCP2 implants. This was probably caused by the presence of calcium oxide impurities in BCP1 and the more intimate mixture and stable ultrastructure of BCP2. No significant difference about the newly formed bone rate in these two BCP preparations was observed. Very slight variations in sintering conditions appeared to influence the biodegradation behavior of the two MBCP implants despite their identical HA/-TCP ratios and similar porosity. Precise and com-plete in vitro characterization enabled us to understand and predict in vivo degradation behavior. 43. J Mater Sci Mater Med, 1999;10:111-20 Role of interconnections in porous bioceramics on bone recolonization in vitro and in vivo. Lu JX, Flautre B, Anselme K, Hardouin P, Gallur A, Descamps M, Thierry B. Summary: The inter favour bone i hydroxyapatite (HA) and beta-tricalcium phosphate (beta-TCP) with the same porosity of about 50% and a mean pores size of 100-300 microm and a mean interconnection size of 30-100 microm. In vitro, four discs for osteoblast culture were studied after 14 and 28 days of incubation. The results sho but the most fa weeks. Th group the rate of calcification and bone ingrowth do not differ, and chondroid tissue is observed inside pores. But in beta-TCP, the calcification rate and the bone ingrowth increased significantly. At week 12 significant correlation between new bone ingrowth and the size of the interconnections i size only al new bone ingrowth inside the pores. We propose the concept of „interconnection density“ which expresses the quantity of links between pores of porous materials rials, pore density densities are equally important.

26

Tel. (+49) 0 73 09 / 8 72-6 00 | Fax (+49) 0 73 09 / 8 72-6 35 | www.bredent-medical.com | e-mail info-medical@bredent.com


44. Gerodontology, 1998;15:25-34 Age changes in bone. Boyde A, Kingsmill VJ. Summary: Changes in bone structure as a function of age have been studied by simple inspection, x-ray imaging, stereo-photography, deep field optical microscopy, circularly polarised light microscopy, and scanning electron microscopy (SEM), including both topographic and compositional backscattered elec modelling and remodelling processes in context. The study of ultra-flat block surfaces permits the acquisition of data from an effectively very thin layer in the block face, and to examine bone as a spectrum of tissue types varying in the degree of mineralisation. Particular attention has been paid in o bones. Recently, we have compared findings from these sites with observations on the mandible. We conclude, from our new imaging data, that common generalisations about the changes in bone in ageing and osteoporosis are too simplified, and that the mandible differs sufficiently from post-cranial skeletal sites that it would be unwise to extrapolate from findings in the jaw to the cir-cumstances elsewhere. 45. Clin Oral Implants Res, 1998;9:137-50 Evaluation of filling materials in membrane--protected bone defects. A comparative histomorphometric study in the mandible of miniature pigs. Buser D, Hoffmann B, Bernard JP, Lussi A, Mettler D, Schenk RK. Summary: In recent outcome of bone reconstructive therapy for defects in the alveolar process. In the present study, 4 different filling materials were evaluated in bone defects of s with barrier programm or subs tive propert In addition, 87% of the graft surfaces were already covered by bo-ne at this time. Both values were significantly higher for autografts than for the 4 alternative bone fillers (P < or = 0.05). At 12 weeks, these differences were no longer apparent, with all 5 filling materials showing similar values. Among the tested bone substitutes, tricalcium phosphate (TCP) showed a significantly higher percentage of bone fill at 24 weeks of healing. It can be concluded that sites filled with autografts clearly demonstrated the best results underneath barrier membranes in the early phase of healing. As far as degradation and substitution are concerned, TCP showed the most promising results. This filler, however, needs to be tested further in a mo freeze-dried bone allografts. 46. Int J Prosthodont, 1998;11:391-401 Mechanisms of endosseous integration. Davies JE. Summary: Although the cl sight into th endosseous implants is believed to be critical in developing biologic design criteria for implant surfaces. RESULTS AND DISCUSSION: This discussion paper enologically subdivided into three distinct phases that can be addressed experimentally. The first, os-teoconduction, relies on the migration of differentiating ost surface is a fun that seen in ceme facial bone formed interface comprising de novo bone formation. CONCLUSION: Treatment outcomes in dental implantology will be critically dependent on implant surface designs that optimize the biologic response during each of these three distinct integration mechanisms. 47. Int J Oral Maxillofac Implants, 1998;13 Suppl:11-45 Report of the Sinus Consensus Conference of 1996. Jensen OT, Shulman LB, Block MS, Iacono VJ. Summary: Retrospective data from sinus floor augmentation bone grafts were collected from 38 surgeons for 1007 sinus grafts that involved the placement of 2997 implants over a 10-year period, with the majority of the implants followed for 3 years or more postrestoration. There were 229

27


implant failures reported. Various root-form implants and grafting modalities were used. A consensus conference was organized to evaluate the data an in sinus grafts analyzed. However, the database was so multi-variate and multifactorial that it was difficult to draw definitive conclusions; these must await controlled pr review for bone gra tions, prosthetics, and nomenclature. Several consensus sta-tements were obtained, the most significant being that the sinus graft should now be considered a highly predictable and effective therapeutic modality. 48. Anat Rec, 1996;245:426-45 In vitro modeling of the bone/implant interface. Davies JE. Summary: BACKGROUND: The purpose o candidate implant materials. METHODS: The central ob surfaces. It should be that cell culture retrospective, it is shown that primary differentiating osteogenic cell cultures, derived from bone marrow, illustrate a sequence of extracellular matrix el surfaces events. In each case the first biologically derived matrix at these sites is a morphologically distinct collagen fibre-free extracellular matrix, which, in bone histology has been referred to for > 100 years as a cement line. RESULTS: The sequenc bone sialoprot morphologically identifiable collagen fibres. This is clearly contrary to the dogma that collagen is necessary for mineralization of bone, but is in agreement with specific cases of other, particularly dental, calcified connective tissues. Although collagen is synthesized by the differentiating osteogenic cells t ment line matrix, collagen fibre assembly occurs and is then mineralized to produce morphologically identifiable bone matrix. CONCLUSION: Key elemen these in vi surfaces. However, distinction is drawn between the events of new bone formation at implant surfaces and other bone/implant morphologies, which are unrelated to de novo bone formation at the implant surface. Finally, this new information emerging from bone marrow cell culture studies demands a re-examination of the concepts of bone-bonding and non-bonding implant materials.

bredent medical GmbH & Co.KG | Weissenhorner Str. 2 | 89250 Senden | Germany Tel. (+49) 0 73 09 / 8 72-6 00 | Fax (+49) 0 73 09 / 8 72-6 35 | www.bredent-medical.com | e-mail info-medical@bredent.com Irrtum und Änderungen vorbehalten / Subject to changes 05/09 000365EX 3

ossceram nano  

Dr. Jörg Neugebauer, University Cologne/Germany An analysis of the literature with the search terms TCP, HA, BCP in combination with dental...