Evaluation of Marginal Adaptation of Direct and Semi-direct Resin Restorations Using Stereomicroscopy: An In Vitro Study

Objective: This study aimed to evaluate the marginal adaptation at the tooth-restoration interface of Class II box-type cavities restored using direct and semi-direct techniques with two different types of composite materials. Materials and Methods: Class II box-shaped cavities were prepared in 28 extracted maxillary premolar teeth, which were randomly divided into two experimental groups, each consisting of 14 samples. • Group I: Direct composite restorations • Group II: Semi-direct composite restorations Each group was further subdivided into two subgroups (A and B), comprising 7 samples each based on the type of composite material employed, specifically Nova Compo C and Estelite Sigma Quick, along with their corresponding adhesive systems. Following restoration, all samples were longitudinally sectioned in a mesiodistal direction to create two halves (buccal and lingual). Marginal adaptation was assessed by measuring gaps at the toothrestoration interface under a 40X stereomicroscope, supplemented by a 10X digital camera and specialized software. The gingival floor was analyzed at four distinct points on the buccal and lingual halves, with gap measurements taken at each site. The collected data were tabulated, and statistical significance was determined using the T-test (p < 0.05). Results: The findings indicated no statistically significant differences in marginal adaptation along the gingival floor between the direct and semi-direct restorative techniques. However, among the composite materials examined, Estelite Sigma Quick demonstrated superior adaptability compared to Nova Compo C. Conclusion: This study concluded no significant difference in marginal adaptation between the direct and semi-direct restoration techniques along the gingival floor. However, the type of composite resin utilized significantly affected marginal adaptation, with Estelite Sigma Quick exhibiting reduced gap formation compared to Nova Compo C