A Novel Technique for Bulk-Fill Resin-Based Restorations: Achieving Function and Esthetics in Posterior Teeth

Hindawi Case Reports in Dentistry Volume 2017, Article ID 9408591, 5 pages https://doi.org/10.1155/2017/9408591 Case Report A Novel Technique for Bulk-Fill Resin-Based Restorations: Achieving Function and Esthetics in Posterior Teeth Gerardo Durán Ojeda,1 Ismael Henrı́quez Gutiérrez,1 José Pablo Tisi,1 and Abelardo Báez Rosales2 1 2 Facultad de Ciencias de la Salud, Universidad Arturo Prat, Iquique, Chile Restorative Dentistry Department, University Andrés Bello, Viña del Mar, Chile Correspondence should be addressed to Gerardo Durán Ojeda; Received 21 July 2017; Accepted 22 October 2017; Published 26 November 2017 Academic Editor: Michelle A. Chinelatti Copyright © 2017 Gerardo Durán Ojeda et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Advances in the mechanical properties of composite resins have allowed for their use in posterior teeth. Conventional resins have several problems associated with polymerization shrinkage stress. The development of “bulk-fill” resins has allowed for their use in single increments up to depths of 4 mm, with very low polymerization shrinkage stress. Nevertheless, differences in anatomy and the desire for optimal esthetics present unique difficulties. This article describes a step-by-step technique using flowable bulk-fill resin as a substitute for dentin in a single increment, together with a high-reflective-index resin to restore enamel and decrease clinical time, obtaining anatomically and esthetically acceptable results without detriment to the mechanical properties required to restore the functionality of the posterior teeth. 1. Introduction Posterior teeth represent a scenario of variable complexity when clinicians are performing a direct or indirect restoration using adhesive-resin-based materials. The application of conventional resins using the stratification technique is associated with the risk of incorporating bubbles and impurities, longer clinical time, and polymerization shrinkage stress [1–3]. Additionally, subsequent problems arising from polymerization shrinkage stress can occur, such as microleakage at the margins [1], cuspal deflection and enamel cracks [4–6], an increased predisposition to the formation of secondary caries, and postoperative sensitivity [7, 8]. Despite issues with the stratification technique in the posterior teeth, the longevity of these restorations has been examined in previous reports with high rates of clinical success based on randomized and retrospective longitudinal studies, with results showing survival times of up to 18–20 years [9–12]. Given the problems associated with polymerization shrinkage stress, new composite resins, termed “bulk-fill” resins, are now available on the dental market for use in single-increment applications up to 4–5 mm [13]. These resins initially had a flowable consistency for use as base materials or liners, which are then complemented with a final layer of a conventional composite resin. The first of these materials was SureFil® SDR® flow (DENTSPLY, Konstanz, Germany), which used “stress decreasing resin” (SDR) technology and provided greater flexibility, allowing for dissipation of stress during the polymerization reaction [14]. The present case report details a step-by-step procedure to restore two molars with old failed amalgam restorations classified as “Charlie” according to the Modified United States Public Health Service (USPHS) Ryge Criteria for Direct Clinical Evaluation of Restoration, which presented color mismatch, marginal discoloration, loss of restorative substance in the anatomic contour, microleakage, and secondary caries. This led to the decision to restore with a new restoration instead to repair both amalgams and the remaining tooth structure. The technique of choice in this case includes a mix of a flowable bulk-fill resin, with the anatomical completion of the enamel using a conventional restorative resin. An 18-month follow-up allowed for evaluation of the results. 2 Figure 1: Failed OV amalgam filling in tooth 36 and an old occlusal amalgam restoration in tooth 37. Case Reports in Dentistry base surface of both tooth preparations in single-layer increments until the dentin was completely full, leaving sufficient space (approximately 1 mm) to apply an enamel resin material (Figure 4). Once this layer was placed, it was polymerized for 20 sec. To complete the occlusal morphology of both teeth, a conventional stratification resin was selected (UE1, ENA HRi, Micerium S.P.A., Avegno, GE, Italy) that was applied in single-layer increments to complete the final anatomy of the lost enamel, after which it was light-cured for 40 sec (Figures 5 and 6). To characterize these teeth, flowable resin pigmentations were applied (Brown2, Micerium S.P.A., Avegno, GE, Italy) (Figure 7). A final polymerization through a layer of glycerin was performed for 40 sec for each tooth to eliminate the polymerization inhibition layer. Finally, finishing and polishing were performed. In this case, the procedure started with Enhance diamond points (Enhance®, DENTSPLY, Konstanz, Germany) for prepolishing, together with diamond polishing pastes (Shiny A and Shiny B, Micerium S.P.A., Avegno, GE, Italy) and a final aluminum oxide paste (Shiny C, Micerium S.P.A., Avegno, GE, Italy). An immediate control image is shown in Figure 8 and 18-month follow-up in Figure 9. 3. Discussion Figure 2: Elimination of the failed 36 OV amalgam and the occlusal amalgam in tooth 37 under rubber dam isolation. 2. Case Report A 52-year-old female patient presented to the private practice of one of the authors with a main complaint of two old failed amalgam restorations in teeth 36 (OV) and 37 (O), requesting that these restorations be replaced with new composite resins. After a complete clinical examination, it was determined that both teeth were vital (Figure 1). Under rubber dam isolation, the elimination of the old amalgams was performed with carbide burs (H4MCL.314.012, Komet, Gebr. Brasseler GmbH & Co., Germany), attempting to spare a healthier dental structure (Figure 2). Once the tooth preparations were completed, the adhesive technique was performed on both teeth in the same manner. Initially, the enamel was etched with 37.5% phosphoric acid (Gel Etchant, Kerr, Orange, CA, USA) for 15 sec, after which the dentin was etched for 15 sec. The acid was then rinsed off with an air/water spray for 30 sec and air-dried, taking care not to desiccate the dentin. After the tooth surface had been treated, a first layer of primer was applied to the dentin and rubbed using a microbrush for 20 sec (Primer, OptiBond FL, Kerr, Orange, CA, USA). For the enamel, primer was applied gently without rubbing. An air jet allowed for primer runoff and solvent volatilization, after which a thin layer of bonding was applied an (...truncated)