Restaurações de resina composta em dentes posteriores - efetividade de contato proximal e efeito de associação com cimento de ionômero de vidro nas tensões residuais

Abstract

This study aimed to evaluate the biomechanics performance of resin composite restorations in posterior teeth by two general objectives: analyzing the proximal contact forces influenced by resin composite type and aging; and the effects of associations with resin modified glass ionomer base under different thicknesses and mechanical properties in the shrinkage stress. This thesis is structured in three specific objectives: Objective 1: To measure the proximal contact force (N) of incremental and bulk fill class II resin composite restorations from proximal contact with implant molar teeth and with adjacent premolar teeth simulating the periodontal ligament. Objective 2: To evaluate the post-gel shrinkage (Shr), compressive strength (CS), diametral tensile strength (DTS), flexural strength (FS), elastic modulus (E), and radiopacity of resin-modified glass ionomer (RMGIC) and bulk fill resin composite (BFRC) used for restoring posterior teeth. Objective 3: Evaluates the effect of resin-modified glass ionomer filling the pulp chamber on stress distribution in young molar treated endodontically and restored with bulk fill resin composite, using patient-specific finite element analysis (FEA). I t can be concluded that the proximal contact force decreased after 5 years of simulated occlusal fatigue. The bulk-fill technique showed proximal contact force similar to the incremental technique. The different compositions of RMGICs and resin composites bulk-fill can influence their mechanical and physical properties. RMGIC, which have a lower elastic modulus and less post-gel shrinkage when used as base materials for resin composite bulk-fill restorations, which have a higher elastic modulus, result in less stress in the dental structures. The 3.0 mm thickness of the RMGIC inserted into the pulp chamber caused less stress on the remaining tooth structure. The general context of this study demonstrated that the proximal contact force of posterior restorations with resin composite bulk-fill is similar to the proximal contact forces of conventional resins; RMGIC and resin composite bulk-fill have different mechanical properties and, when well combined, are a viable option for restoring endodontically treated posterior teeth, generating less stress on the tooth structure.