CLINICAL
Composite inlays as an alternative in the posterior region Dr Sanzio Marques and Dr Márcia Marcondes Guimarães
T
oday, composite restorations are regarded as a reliable alternative for the posterior region and combine both aesthetics and longevity. However, for the success of any restoration, it is fundamental that the dentist has a good command of the technique and materials. This article shows, step by step, the chairside fabrication of an indirect composite restoration on a molar. This is followed by a discussion of the indications, advantages and properties of this technique which not only cuts costs but which is also high in quality and simple to use.
Introduction The adhesion of restorations on the remaining dental hard tissue represented a major turning point for conservative treatment. The introduction of new materials not only helped to improve aesthetics, but also facilitated the restoration of the shape, strength and function of carious and traumatised teeth. And all this combined with the major advantage of the restorations being conservative and minimally invasive, without having to remove large amounts of tooth substance as was previously necessary with cavity preparations, e.g., for amalgam restorations. It is also general knowledge that the composites frequently used in the posterior region are subject to polymerisation shrinkage which, in the case of the incorrect use or disregard of this property common to all restorative composites, can lead to internal tension. If this tension exceeds the strength of the bond, this can result in marginal deficiencies or even cracks in the dental hard tissue and restoration. This occurs predominantly with larger cavities as a greater amount of composite materials increases the shrinkage tension (Davidson & DeGee, 1984; Lambrechts et al., 1977; Dietschi & Spreafico, 1997). Thus in the posterior region, particularly with larger cavities, the restoration result may be compromised. This is because this area is harder to access, which can cause problems when preparing the cavity margins and contouring the anatomy and also when creating physiological approximal contacts (Imparato et al., 1999). In light of these well-known factors, many dentists opt for indirect restorations produced in laboratories to treat larger cavities. This allows the restoration to be fabricated without having to deal with intraoral difficulties, thus offering improved contouring and the easier creation of correct approximal contacts with the optimal physical properties of the restoration material. However, there are a number of disadvantages associated with indirect methods, these include the need for a large number of sessions, the production of temporary restorations and higher costs due to the laboratory work (Bussadori et al., 1995). A very good alternative for the above-mentioned cases is the comparatively easy restoration technique using a chairside-produced inlay which combines the advantages of direct techniques with those of indirect techniques and is also associated with a reduction in costs and reduced time requirements. The clinical case below describes, step by step, the restoration of a posterior tooth using this technique.
Clinical case The female patient had an insufficient fractured amalgam restoration in tooth 16 (Fig. 1). She complained of discomfort in this tooth. The planned treatment comprised the replacement of the amalgam restoration with a chairside-produced indirect composite inlay, since this was a larger restoration. The GrandioSO Inlay System (VOCO) was selected for the creation of the inlay; this system includes all the necessary and coordinated material components. The amalgam restoration was firstly removed and a base layer was applied using the glass ionomer composite cement Ionoseal (VOCO) in order to smooth over the floor of the cavity and achieve an adapted cavity shape (Fig. 2). The cavity was prepared with special diamond burrs so that no undercut areas remaine Then an impression of the cavity and adjacent teeth was taken with alginate (Hydrogum, Zhermack) (Fig. 3). After the alginate had set, a silicone model was created using special A-silicone (die silicone, VOCO) (Figs. 4 and 5). The next step involved the application and modelling of the nanohybrid composite GrandioSO (VOCO, Fig. 6). Here every single layer, including the interior surface, was light-cured for 20 seconds. The pigments ochre and brown (Kolor+Plus, Kerr) were used for the surface characterisation of the fissures. The diamond-interspersed silicone polisher, Dimanto (VOCO, Fig. 8), a goat hair brush, Opal paste (Renfert) and a wool wheel were used one after the other for finishing and polishing. After the site had been dried completely, the steps for adhesive cementation of the restoration were performed. The prepared cavity was firstly cleaned with a Robson mini brush and a water-based pumice stone paste.
Fig. 4 – Filling of the alginate impression using the die silicone
Fig. 5 – Silicone model after curing (3 minutes) and demoulding.
Fig. 6 – Application in layers and modelling of the composite GrandioSO (VOCO) in shade A3
After the chemical curing of Bifix QM, the rubber dam was removed, the occlusion was ground and the restoration margins were polished using Dimanto (VOCO), brushes and felt polishers. The final inlay is characterised by its optimal aesthetics and shape which ensures ideal functionality (Fig. 12).
Discussion The composites which are available on the dental market are ideal for performing restorations given their aesthetic, adhesive and mechanical properties as well as their ease of handling. Since Buonocore developed the enamel etching technique in 1955 and Bowen introduced the composite based on BisGMA (Bisphenol A-glycidyl methacrylate) in 1963, composites have seen a continuous development not only in terms of their mechanical properties but also their aesthetic qualities, which is why they are now increasingly indicated as restoratives. The direct and indirect or direct-indirect restoration techniques with composites have both their indications and advantages and disadvantages, as is evident from the wealth of research work found in specialist dental literature. However, according to Porter (1990), the direct-indirect technique achieves a more resilient marginal seal as well as greater restoration strength and, in addition, facilitates the creation of the contact points and the correct shading which serves to ensure improved aesthetics. Another important perspective relates to the contraction forces which arise from the polymerisation of excessively large composite increments and can impair their adhesion to the tooth. Various authors consider this to be an important factor when selecting a restorative technique and point out that when treating larger defects, the direct-indirect technique enables greater control over polymerization shrinkage of the composite which, in turn, leads to a reduction in some of the problems which are seen after placement of a restoration, e.g., hypersensitivity, pain and masticatory problems (Davidson & DeGee, 1984; Lambrechts et al., 1977; Dietschi & Spreafico, 1997). Chaim & Baratieri (1998) described that the semi-direct restorative technique offers the advantages of the indirect technique and, at the same time, allows work to be concluded in a single session. The adhesive technique also enables a significant amount of healthy dental hard tissue to be preserved which probably delays the need for more complex, extended and expensive restorations (Chaim & Baratieri (1998), Dietschi & Spreafico, 1997).
Fig. 7 – Careful removal of the inlay from the Fig. 8 – Finishing and polishing with the silicone model diamond-interspersed polisher Dimanto (VOCO)
Fig. 9 – The adhesive Futurabond DC (VOCO) is applied in the cavity.
Figs. 10 and 11 – Direct application of the luting cement Bifix QM (VOCO) in the prepared cavity and careful placement of the composite inlay.
Literature 1. DAVIDSON, C.L. & DEGEE, A. J.: Realization of polymerization contraction stresses by flow in dental composites. J Dent Res, 1948, v.63, p.146-148. 2. LAMBRECHTS, M.; BRAEM, M; VANHERLE, G.: Evaluation of clinical performance for posterior composite resins and dentin adhesives. Oper Dent 1987; v.12, p.53-78. 3. DIETSCHI, D. & SPREAFICO, R.: Adhesive metal-free restorations: current concepts for the esthetic treatment of posterior teeth. 1a. Ed. German: Quintessence, 1997. 4. IMPARATO, J.C.P. et al.: Reconstrução de molares decíduos através da técnica restauradora indireta com resina composta – acompanhamento clínico e radiográfico de dois anos. RPG, 1998, v.5, n.2, p. 133-137. 5. BUSSADORI, S. C; IMPARATO, J.C.P.; GUEDES-PINTO, A, C.: Manual de materiais dentários e técnicas em dentística odontopediátrica. São Paulo: Banco de Boston, 1995. 6.BUONOCORE, M. G.: A simple method of increasing the adhesion of acrylic filling materials to enamel surface. J. Dent. Res., 1955, v. 34, p. 849. 7. BOWEN, R.L.: Properties of a sílica-reinforced polymer for dental restorations. J. Am Dent Assoc., 1963, v.66, p.57-64. 8. PORTER, K.H.: Posterior composite resin inlays and onlays: a comparison of avaible systems. Tex Dent J, 1990, v.107, n.5, p.9-11. 9. LAMBRECHTS, M.; BRAEM, M; VANHERLE, G.: Evaluation of clinical performance for posterior composite resins and dentin adhesives. Oper Dent 1987; v.12, p.53-78. 10. CHAIM, M.C. & BARATIERI, L.N.: Restaurações indiretas de resina composta em dentes posteriores, in: CHAIM, M.C. & BARATIERI, L.N.: Restaurações estéticas com resina composta em dentes posteriores. São Paulo: Artes Médicas, 1998, p.131-168. 11. MONELLI, R.F. et al.: Conservative approach to restore the first molar with extensive destruction: A 30-month follow-up. Quintessence Int, 2013, v.44, n.6, p.385-91.
The tooth was cleaned and then rinsed thoroughly with water and the cavity was gently dried with air. A not too thin layer of the self-conditioning adhesive Futurabond DC (VOCO) was applied inside the cavity and rubbed in for 20 seconds (Fig. 9). In order to accelerate evaporation of the solvent, the adhesive was gently dried with a stream of air. This was followed by light polymerisation for at least 10 seconds. The dual-curing composite cement Bifix QM (VOCO) was applied directly to the cavity surfaces (Fig. 10), the inlay was carefully put into place and held down by applying pressure (Fig. 11); the excess cement was removed with a brush and dental floss. Every tooth surface was then polymerised with light.
Fig. 2 – Cavity lined with Ionoseal (VOCO) for smoothing the cavity walls and postpreparation.
Fig. 1 – Initial situation with the fractured and insufficient amalgam restoration on tooth 16
Fig. 2 – Cavity lined with Ionoseal (VOCO) for smoothing the cavity walls and postpreparation.
Fig. 12 – The final result with the chairside-produced composite inlay
Information on the authors Dr Sanzio Marques is a practising dentist and specialises in conservative dentistry and prosthodontics in Belo Horizonte, Brazil. He also lectures at the Federal University of Minas Gerais and at the University of São Paulo. He is the author of various reference books and is a course instructor at several specialist institutions. Contact details: www.sorrisobelo.com.br Márcia Marcondes Guimarães is a dentist at the School of Dentistry at the University of São Paulo and specialises in implantology, periodontology and prosthodontics. Grandio®SO Inlay System Set for chairside fabrication of indirect composite inlays VOO has extended its successful GrandioSO line by adding an innovative set for chairside fabrication of indirect composite inlays. The GrandioSO Inlay System makes VOCO the only manufacturer to offer such an all-in-one solution. The system set makes 15 indirect composite inlays, with chairside fabrication being equally simple and quick, making it unnecessary to involve a laboratory in the process. There is also no requirement for the use of expensive CAD/CAM equipment in order to create high-quality inlays. All components contained in the set are optimally matched and make it possible to extraorally fabricate, in just one sitting, composite inlays that are as stable as they are aesthetic. In addition to the tried and tested products GrandioSO, Futurabond DC, Bifix QM and Dimanto, the system set also contains a new, specially developed addition-curing silicone material for the fabrication of model teeth. This silicone is a high-definition material with high final hardness. Using conventional techniques, it produces realistic models that are ideal for use in the fabrication of inlays. The composite inlay is created extraorally, according to the principles applying to the placement of fillings, and the restoration is then inserted into the cavity lege artis. The patient is thus treated with a high-quality composite inlay in just one sitting. Manufacturer: VOCO GmbH, PO Box 767, 27457 Cuxhaven, Germany, www.voco.com, info@voco.com
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