X-Ray Microtomography Analysis of Gaps and Voids in the Restoration of Non-Carious Cervical Lesions with Different Composite Resins

Abstract

Context (Background): Resin composites are the most widely used material for restoring cervical defects. However, the high failure rate of these restorations is still a concern. Aims: The aim of this in vitro study was to evaluate, using microtomography (μCT), the interfacial gap and voids formation in Class V cavities in premolars restored with materials with lower polymerization shrinkage combined with different restorative techniques. Settings and Design: Cervical defects were created in 30 intact premolar and were randomly distributed to be restored by one of the following techniques (n = 6): Composite resin with two increments (CR), organic modified polymer (ORMOCER) with single (OR1) or two increments (OR2, or low viscosity bulk-fill composite resin with single (BF1) or two increments (BF2). Methods and Material: Each tooth was scanned before filling to determine the volume of interest (VOI) to be applied in the second μCT after restoration and to control the cavity volume among the groups. In the μCT after filling, the volume of interfacial gaps and voids was calculated for each group. Statistical Analysis: The groups were compared using one-way and Tukey HSD post hoc test (α = 0.05). Results: It was possible to identify higher gap formation in the OR1 group and higher void formation in CR group (P < 0.05). OR2 group showed better results than the group with one increment. BF2 showed the best filling capacity. Conclusions: It was possible to conclude that the material and the number of increments directly influenced the internal adaptation and voids formation of Class V restorations.