Scientific Highlights
SHORT OVERVIEWS ON RECENTLY PUBLISHED SCIENTIFIC EVIDENCE.
September – October 2019
Edited by Dr Marcin Maj
In this issue
In this issue… in this issue
Enamel matrix derivative improves root coverage and keratinized tissue width in the treatment of periodontal recession.
(Mercado F et al. 2019)
Computer-guided surgery for allograft ring placement and simultaneous implant insertion.
(Simpson KT et al. 2019)
Stress distribution in ceramic and titanium implants in alveolar sockets.
(Ferraz CC et al. 2019)
Editor’s choice
Int J Periodontics Restorative Dent. 2019 Sep/Oct 39(5):633-641
Preservation of peri-implant hard tissues following immediate postextraction implant placement. Part I: Radiologic evaluation.
Cardaropoli D, Tamagnone L, Roffredo A, De Maria A, Gaveglio L
Study objectives
This study evaluated the insertion of implants in intact fresh extraction sockets in the anterior maxilla. The bone-to-implant gap was accurately grafted with a bovine bone mineral prior to implant engagement, and an immediate screw-retained restoration was delivered After 3 months, the provisional crown was replaced with the definitive ceramic crown. After 1 year, marginal bone levels and horizontal ridge dimension (at three levels using CBCT scans) were evaluated.
Results
• Marginal bone levels remained stable after 1 year.
• The horizontal width of the postextraction crest was well-preserved independently from the thickness of the buccal bone plate at baseline.
Adapted from Cardaropoli D et al., Int J Periodontics Restorative Dent. 2019 Sep/Oct 39(5):633-641, for more info about this publication click HERE
Highlights
J Periodontol. 2019 Sep 27
Subepithelial connective tissue graft with or without enamel matrix derivative for the treatment of multiple Class III-IV recessions in lower anterior teeth: A 3-year randomized clinical trial.
Mercado F, Hamlet S, Ivanovski S
Study objectives
The aim of this randomized study was to compare clinical and patient-centered outcomes of subepithelial connective tissue graft (CTG) with and without enamel matrix derivative (EMD) in the treatment of multiple Class III-IV Miller periodontal recession (REC) defects on mandibular anterior teeth. In total 41 patients were evaluated at 3 years follow-up. A total of 156 teeth were divided into two groups: test (CTG-EMD: n=79 teeth) and control (CTG only: n=77 teeth). Clinical REC, keratinized tissue (KT) width, percentage of root coverage and patient-centered outcomes were compared between the two groups.
Results
• Patient-level analysis showed that REC in the test group reduced significantly (5.71 ±0.58 mm to 1.57 ±0.85 mm) compared with the control group (5.94 ±0.46 mm to 2.51 ±0.62 mm) (p<0.001)
• KT width increased in the test group (1.51 ±0.26 mm to 4.18 ±0.34 mm) and was significantly greater than the control group (1.65 ±0.21 mm to 2.90 ±0.20 mm) (p<0.001).
• Tooth-level analysis (Class III and Class IV groups) found less residual REC and increased KT in the test group compared with the control group (p<0.01).
• At 2, 7, and 14 days follow-up post-surgery, significantly less pain was reported in the test group compared to the control group (p<0.001)
Conclusions
• The addition of EMD to CTG improved root coverage outcomes and increased KT width 36 months after treatment of Class III-IV REC on mandibular anterior teeth.
• The adjunctive use of EMD resulted in significantly reduced pain post-surgery
Adapted from Mercado F et al., J Periodontol. 2019 Sep 27, for more info about this publication click HERE
Clin Adv Periodontics. 2019 Sep 12
Computer-guided surgery using the "allograft ring technique" with simultaneous implant placement: a case report.
Simpson KT, Bryington M, Agusto M, Harper M, Salman A, Schincaglia GP
Study objectives
This case report describes a modified protocol for simultaneous placement of implant and allograft ring graft using a computer-guided surgery technique. The patient's chief complaint was to replace a missing lateral incisor. The implant site presented both vertical and horizontal tissue deficiencies. Study models and wax-ups were digitally scanned to stl files and merged with the existing CBCT data in the implant planning software. A 3D representation of an allograft ring was developed, and two digitally designed guides were created: a 5 mm sleeve guide for the implant site and a 7 mm sleeve guide for the allograft ring trephine. Both the implant site and the allograph ring recipient site were prepared using the computer-generated guides. Once the ring was adapted into the recipient site, the implant was inserted through the allograft ring. The healing was monitored and the implant was restored at 12 months.
Results
• The accuracy of implant placement was measured and the difference in the final positioning was as follows: 0.6 mm at entry point, 0.55 mm vertical displacement, 1.94 mm at the apex and 6.1° angle discrepancy.
Conclusions
• The use of computer-guided technology for planning and placement of an allograft bone block with simultaneous implant insertion allows for a prosthetically driven approach to compromised site grafting
• Further, this guided technique improves precision and accuracy compared to non-guided techniques.
Adapted from Simpson KT et al., Clin Adv Periodontics. 2019 Sep 12, for more info about this publication click HERE
J Clin Exp Dent. 2019 Oct 1 11(10):e850-e857
Analysis of stress distribution in ceramic and titanium implants in alveolar sockets of the anterior region of the maxilla.
Ferraz CC, Barros RM, Ferraz FC, Mundstock ÁA, Maior BS
Study objectives
This study aimed to investigate stress distribution in zirconia and titanium implants and their biomechanical response in alveolar sockets of the anterior region of the maxilla through 3D finite element analysis. From computed tomography scans of a reference patient, three models of the maxillary dental arches were designed with Rhinoceros 5.0 software (McNeel Europe™, Barcelona, Spain). In each model, a dental implant replaced the maxillary left central incisor. The implants consisted of Zirconia Pure Ceramic Implant Monotype (M1), Zirconia Pure Ceramic ZLA (M2), or Titanium Bone Level - Roxolid SLA (M3). Ceramic crowns were installed in all the implants. Implants and prostheses were loaded with 50 N oblique and axial forces. Von-Mises and Mohr Coulomb criteria were used to assess stress distribution in the implant systems and perimplantar bone, respectively
Results
• Traction was detected in the cervical region of the palatal bone surface of all the models.
• Compression was found in the cervical region of the vestibular bone surfaces
Conclusions
• Zirconia Pure Ceramic Implant Monotype (M1) had the best response under oblique force loading.
• Ceramic implants may be an alternative to replace titanium implants in fresh alveolar sockets in the anterior region of the maxilla
Adapted from Ferraz CC et al., J Clin Exp Dent. 2019 Oct 1 11(10):e850-e857, for more info about this publication click HERE
Clin Oral Implants Res. 2019 Nov 30(11):1142-1154
Excessive occlusal load on chemically modified and moderately rough titanium implants restored with cantilever reconstructions. An experimental study in dogs.
Lima
LA, Bosshardt DD, Chambrone L, Araújo MG, Lang NP
Study objectives
The aim of this study in dogs was to evaluate the outcomes of excessively loaded implants Mandibular premolars were extracted in 5 dogs. After 3 months, each dog received 6 implants (SLA®: n=3; SLActive®: n=3) at Day 0 Four weeks after surgery, both types of implants were restored with either one single crown with stable occlusal contacts (SC), one crown and a cantilever unit with excessive occlusal contacts (OL), or a non-loaded implant (NL). The following treatment modalities were evaluated: (1) SC SLA®; (2) OL SLA®; (3) NL SLA®; (4) SC SLActive®; (5) OL SLActive®; and (6) NL SLActive® Bleeding-onprobing (BoP), relative attachment level (AL), mucosal marginal position (GM) were assessed. Resonance frequency analysis (RFA) was assessed weekly. Standardized X-rays were taken at Day 0, and at 4 and 24 weeks.
Results
• Similar findings were observed for SLA® and SLActive® implants regarding modified plaque index (PlI), modified bleeding index (GI), GM, AL, and bone level (BL)
• No significant differences were detected between implant loading and the 24-week follow-up or between treatment modalities for all clinical parameters (p>0.05).
• Six months after loading, RFA values were significantly greater than at implant placement; no significant differences between treatment modalities were found.
• Linear radiographic measurements yielded similar results between SLA® and SLActive® implants.
• OL SLA® implants yielded a statistically significant gain on peri-implant bone density over all other groups (p=0.012).
• Technical complications: Loosened occlusal screws occurred in 13.3% (SC: 3.3%; OL: 10%), while abutment fractures totalized 23.3% (SC: 6.6%; OL: 16.6%)
Conclusions
• Excessive occlusal load applied to implants (SLA® or SLActive®) restored with cantilevers did not cause loss of osseointegration or significant changes in their clinical, radiographic, or histologic outcomes.
• Early excessive occlusal load on SLA® implants promoted a gain in peri-implant bone density.
• Excessively loaded implants showed more technical complications
Adapted from Lima LA et al., Clin Oral Implants Res. 2019 Nov 30(11):1142-1154, for more info about this publication click HERE
Eur J Prosthodont Restor Dent. 2019 Oct 17
Evaluation of marginal and internal adaptation of endocrowns fabricated from three different CAD/CAM materials.
Hasanzade M, Moharrami M, Alikhasi M
Study objectives
This in vitro study aimed to compare the internal and marginal discrepancies of endocrowns fabricated from different ceramics before and after adjustment. In total 36 endocrowns were fabricated from lithium disilicate (IPS e-max CAD), zirconiareinforced lithium silicate (Suprinity), and polymer-infiltrated ceramic network (Enamic) using a CEREC intraoral scanner and milling unit. A reference point matching scan protocol was used to measure the endocrowns’ fit.
Results
• There was no significant interaction between the fabrication materials and adjustment (p>0.05).
• Type of the materials did not change discrepancies at cavosurface, line angle, cavity wall, and pulpal floor (p>0.05); on the contrary, adjustment significantly decreased the discrepancies at all four sites (p<0.001).
• There were significant differences between every two sites before adjustment (p<0.001).
• After adjustment, except for cavosurface and cavity wall (p=0.058), the differences between other sites remained significant (p<0.001)
Conclusions
• IPS e-max CAD, Suprinity, and Enamic endocrowns were not significantly different regarding internal and marginal discrepancies.
• However, it is suggested to adjust these materials to fall in a clinically acceptable range of discrepancies to minimize the risk of caries and periodontal disease
Adapted from Hasanzade M et al., Eur J Prosthodont Restor Dent. 2019 Oct 17, for more info about this publication click HERE
Braz Oral Res. 2019 Sep 30 33(suppl 1):e063
Prevalence of peri-implant diseases - a critical review on the current evidence.
Cosgarea
R, Sculean A, Shibli JA, Salvi GE
Study objectives
The objective of this review was to evaluate the current evidence reporting on the prevalence of peri-implantitis and to determine the influencing factors. An electronic search for articles published until February 2019 reporting on the prevalence of peri-implantitis was performed in MEDLINE. Included papers were analyzed for factors affecting the reported prevalence values for peri-implantitis.
Results
• In total 25 papers were included and the reported prevalence of peri-implantitis varied widely.
• Significant factors contributing to the observed range of prevalence values were the definition of peri-implantitis with various thresholds for bone loss, and reporting on patient- or implant-level
• Additionally, different follow-up times and populations may have influenced the prevalence values.
Conclusions
• A wide range for reporting the prevalence of peri-implantitis can be found and no real estimation of the global burden of the disease can be made.
• Applying accurate case definitions for peri-implantitis is the most important factor for reporting the prevalence and should be strictly followed in future reports.
Adapted from Cosgarea R et al., Braz Oral Res. 2019 Sep 30 33(suppl 1):e063, for more info about this publication click HERE
Int J Oral Maxillofac Implants. 2019 Sep 18
Critical peri-implant buccal bone wall thickness revisited: An experimental study in the beagle dog.
Monje A, Chappuis V, Monje F, Muñoz F, Wang HL, Urban IA, Buser D
Study objectives
This randomized, two-arm in vivo study in healthy beagle dogs aimed to identify the critical buccal bone wall thickness for minimizing bone resorption during physiologic and pathologic bone remodeling A total of 72 implants were placed in healed mandibular ridges of 12 beagle dogs. Two groups were defined; Group 1: 36 implants were placed in sites with a thin buccal bone wall (<1.5 mm), and Group 2: 36 implants were placed in sites with a thick buccal bone wall (≥1.5 mm). Group 1 was sacrificed 8 weeks after implant placement for histomorphometric examination of postsurgical resorption of the buccal bone wall. Group 2 was monitored during three ligature-induced peri-implantitis episodes and a spontaneous progression episode
Results
• No implants failed during the study period.
• For the great majority of the histomorphometric parameters, a critical buccal bone wall thickness of at least 1.5 mm seemed to be essential for maintaining the buccal bone wall during physiologic and pathologic bone resorption.
• Suppuration and mucosal recession were more often associated with implants placed in sites with a thin buccal bone wall
Conclusions
• A critical buccal bone wall thickness of 1.5 mm at implant placement is advised, since a thicker peri-implant buccal bone wall is associated with significantly less physiologic and pathologic bone loss compared to a thinner buccal bone wall.
Adapted from Monje A et al., Int J Oral Maxillofac Implants. 2019 Sep 18, for more info about this publication click HERE
Int Dent J. 2019 Sep 69 Suppl 2:18-22
Surgical treatment of peri-implantitis - Consensus report of working group 4.
Khoury F, Keeve PL, Ramanauskaite A, Schwarz F, Koo KT, Sculean A, Romanos G
Study objectives
This is a consensus report based on four background reviews The surgical treatment of peri-implantitis is indicated in cases where non-surgical treatment failed, with recurrence of bleeding and suppuration. The aim of this review was to systematically screen the literature for possible surface decontamination techniques and materials during surgical treatment, the surgical regenerative and non-regenerative treatments of peri-implantitis, radiological and clinical outcomes, the importance of the presence of fixed and/or keratinized peri-implant gingiva, and to determine predictable therapeutic options for the clinical surgical management of peri-implantitis lesions.
Results
• Existent clinical, radiographic and microbiological data do not favor any decontamination approach and fail to show an influence of any particular decontamination protocol on surgical therapy.
• Using implantoplasty in surgical non-regenerative treatment leads to a significant decrease in bleeding on probing and probing depth, and may result in improvement of clinical and radiographic parameters up to 3 years after surgery, compared with mechanical debridement alone.
• Surgical augmentative peri-implantitis therapy resulted in improved clinical and radiographic treatment outcomes compared with the baseline in the majority of studies with 6 months to 7-10 years of follow-up.
• There is no evidence to support the superiority of a specific material, product or membrane in terms of long-term clinical benefits.
• The best treatment modality to improve the width of keratinized attached mucosa, bleeding and plaque scores, and to sustain the peri-implant marginal bone level, is the use of an apically positioned flap combined with a free gingival graft.
Adapted from Khoury F et al., Int Dent J. 2019 Sep 69 Suppl 2:18-22, for more info about this publication click HERE
J Periodontol. 2019 Sep 1
Extracellular matrix-based scaffolding technologies for periodontal and peri-implant soft tissue regeneration.
Tavelli L, McGuire MK, Zucchelli G, Rasperini G, Feinberg SE, Wang HL, Giannobile WV
Study objectives
The aim of this review was to discuss the properties, clinical application, and limitations of extracellular matrix (ECM)-based scaffold technologies in periodontal and peri-implant soft tissue augmentation when used as alternatives to autogenous soft tissue grafts
Key points
• Different processing methods for the creation of cell-free constructs resulting in preservation of the extracellular matrices influence the characteristics and behavior of scaffolding biomaterials
Adapted from Tavelli L et al., J Periodontol. 2019 Sep 1, for more info about this publication click HERE
Periodontol 2000. 2019 Oct 81(1):124-138
Soft tissue-related complications and management around dental implants.
Chackartchi T, Romanos GE, Sculean A
Study objectives
This review provides an overview of the most important aspects related to the prevention and management of soft tissuerelated complications in conjunction with implant therapy.
Key points
• The current literature indicates that the presence of an adequate width of keratinized attached mucosa around dental implants may lead to better soft and hard tissue stability, less plaque accumulation, limited soft tissue recession, and lower incidence of peri-implant mucositis.
• Proper implant positioning by carefully considering appropriate mesio-distal and bucco-lingual dimensions and implant angulation may prevent the loss of interdental soft tissues and development of soft tissue recessions.
• To optimize the width of keratinized attached mucosa, the appropriate soft tissue augmentation protocol should be selected for each particular indication.
• When the use of autogenous soft tissue grafts is planned, a thorough knowledge of the anatomical structures is mandatory in order to harvest soft tissue grafts of an appropriate quality and quantity and to avoid/minimize postoperative complications.
• The clinician needs to master the necessary steps in order to manage complications related to extensive bleeding and tissue necrosis that may occur in conjunction with soft tissue augmentation procedures
Adapted from Chackartchi T et al., Periodontol 2000. 2019 Oct 81(1):124-138, for more info about this publication click HERE
Periodontol 2000. 2019 Oct 81(1):64-75
Anatomic factors as contributing risk factors in implant therapy.
Ramanauskaite A, Becker J, Sader R, Schwarz F
Study objectives
The aim of this review was to summarize the anatomic structures and their variations in the mandible and maxilla as contributing risk factors in implant therapy.
Key points
• Damage to critical anatomic structures during dental implant placement may occur when the anatomic features of the major blood vessels and their anastomoses, neurovascular bundles, and alveolar ridge contour are not properly investigated prior to the surgery.
• Proper knowledge of specific anatomic factors is key to avoiding intra- and postsurgical complications
Adapted from Ramanauskaite A et al., Periodontol 2000. 2019 Oct 81(1):64-75, for more info about this publication click HERE
References
Cardaropoli D et al., Int J Periodontics Restorative Dent. 2019 Sep/Oct 39(5):633-641 | Mercado F et al., J Periodontol. 2019 Sep 27 | Simpson KT et al., Clin Adv Periodontics. 2019 Sep 12 | Ferraz CC et al., J Clin Exp Dent. 2019 Oct 1 11(10):e850-e857 | Lima LA et al., Clin Oral Implants Res. 2019 Sep 1 | Ali K et al., Evid Based Dent. 2019 Sep 20(3):97-98 | Hasanzade M et al., Eur J Prosthodont Restor Dent. 2019 Oct 17 | Papaspyridakos P et al., J Prosthodont. 2019 Oct 24 | Cosgarea R et al., Braz Oral Res. 2019 Sep 30 33(suppl 1):e063 | Monje A et al., Int J Oral Maxillofac Implants. 2019 Sep 18 | Khoury F et al., Int Dent J. 2019 Sep 69 Suppl 2:18-22 | Tavelli L et al., J Periodontol. 2019 Sep 1 | Chackartchi T et al., Periodontol 2000. 2019 Oct 81(1):124-138 | Ramanauskaite A et al., Periodontol 2000. 2019 Oct 81(1):64-75| source: www.pubmed.gov | Dr Maj holds a position of Senior Global Professional Relationships Manager at Institute Straumann in Basel, Switzerland
