GAP Australasian Dentist Sept Oct 2020

Category 46 Australasian Dentist Introduction Bioactive direct composite resin materials like the next generation high strength injectables and low shrinkage packable composites when used with advanced matrix systems provides clinicians with an opportunity to adopt a minimally invasive patient-centric treatment approach while preserving sound tooth structure. Material selection is an important step in treatment planning for posterior restorations. The use of bioactive composites under strict isolation with rubber dam helps achieve aesthetics and function with long term success while minimizing the risk of secondary caries. Clinicians often find it challenging to restore multiple posterior teeth with direct resin in an efficient and predictable manner. Key to success lies in achieving a well-sealed restoration with good contact and contours. Therefore, restoration of interproximal areas on posterior teeth requires stringent preoperative evaluation of tooth & defect size, location of contact & tightness, adjacent tooth position & contours and gingival location. This article aims to provide a simple and predictable protocol when dealing with adjacent Class II direct resin restorations in routine clinical practice. Patient Case A 21-year-old female visited the dental office with a chief complaint of food lodgment and pain when consuming sweet or cold food in tooth #46. Radiographic examination with IOPA reveled old composite restoration in tooth #46 and #45 decayed distally without involving marginal ridge. Upon clinical examination, Class II cavities on tooth #46 & #45 were identified (Pic 01). The most suitable treatment approach in this situation was direct restorations with bioactive composite resins. Prior to caries removal, proper quadrant isolation was done with placement of rubber dam and pre-wedging with Garrison small FXBL wedge. Pre-wedging creates momentary tooth separation to help achieve a more accurate proximal seal with ideal contact after placement of the final restoration and the teeth return to their original position. In addition, it also helps to protect the rubber dam when removing the caries in the cervical area. Caries removal was completed with a blue stripped high speed small round bur followed by slow speed round carbide bur. Caries detection dye was applied to ensure complete removal of active decayed tooth structure. Old composite was removed from occlusal and buccal pit area of tooth #46. For tooth #45, decay was initially removed mesially without touching the occlusal surface, however as the marginal ridge area was left with very thin structure, the proximal box was later extended to the occlusal surface (C shaped preparation) to avoid excessive stress that could lead to restoration failure. (Pic 02) adhesive monomers resulting in a weaker bond. To achieve reliable adhesion, I prefer to use a 6th generation adhesive system (Shofu FL- Bond) combined with selective etching as the outcome is predictable compared to current 7th generation and universal adhesive systems in the market. Even if you etch dentin, the primer is able to replace water without collapsing collagen and facilitate effective monomer penetration into the demineralized area. To maintain a humid dentinal substrate, a generous amount of primer should be applied and left undisturbed for 10 seconds and air dried for 5 seconds to ensure the solvent evaporates and mild acid primes the dentin. The bonding agent should be carefully applied as an even layer on the entire restorative surface and light-cured for 10 sec or longer in case of deep cavities. Garrison 3D Fusion orange sectional matrix ring (FX500) was selected according to the height of the cavity, in this case we selected FX150 band for premolar and FX175 for the molar. Both bands should be placed simultaneously and secured with suitable wedges. The wedges should be placed and inserted from the buccal side at an angle by holding the bands with a finger to avoid the bands from being displaced from its ideal location. Always good to double check the fit and seating of the bands specially in the proximal box to ensure complete seal when placing the composite resin material. (Pic 03) Simplified protocol for adjacent Class II direct resin restorations clinical Figure 2 – Pre-wedging with removal of active decay for the both teeth Figure 3 After cavity preparation and caries removal, smooth enamel margins were achieved with Super fine diamond bur (yellow band) and proximal walls were finished with Super-Snap Violet disk, to ensure a perfect bonding to the enamel and avoid detachment of unsupported enamel or potential micro leakage. The wedge was removed & selective etching technique was used with 35% phosphoric acid followed by abundant rinsing with water. Avoid over drying the dentin with strong airflow as a completely dried surface will cause collapse of collagen affecting the penetration of Garrison FX150 band for premolar and FX175 for the molar is placed and secured with the Garrison 3D Fusion Blue Wedge along with Garrison 3D Fusion Orange Ring (FX500) was selected according to the height of the cavity. Tip: When restoring adjacent teeth, place both matrix bands at once to avoid Figure 1 – #46 showing MO Class II cavity along with old composite restoration.