Adhesive strength of composite restorations of the cervical region

AIM: To study the adhesive strength of composite restoration with hard tissues in laboratory samples of the frontal and chewing groups of teeth before and after thermal cycling. METHODS: Preparation of test samples. Laboratory methods - determination of the adhesive strength of samples of compressive restorations: 2.1 Before thermal cycling; 2.2 After thermal cycling. Statistical data processing in the SPSS Statistics program RESULTS: The results of a comparative assessment of the adhesive compressive strength showed that in the samples of teeth of the frontal group before thermal cycling in groups 1Fa and 2Fa amounted to 1663.6 (1574.6; 2175.1) N and 2151.5 (967.9; 3970.3) N, respectively. The difference between them is unreliable (p=0.538), which confirms the homogeneity of the groups. After thermal cycling in groups 1Fb and 2Fb, the adhesive compressive strength indicators were 1353.3 (1219.2; 2096.8) N and 1620.7 (847.2; 2434.7) N, respectively. The difference between groups 1Fb and 2Fb is unreliable (p=0.868). The adhesion strength indicators before and after thermal cycling in groups 1Fa and 1Fb (p=0.017) and in groups 2Fa and 2Fb (p=0.017) are statistically significant. In the samples of teeth of the chewing group, the adhesive strength indicators before thermal cycling in groups 1Cha and 2ChA were 4100.0 (2818.1; 48401.4) N and 3800.0 (2000.0; 4500.0) N, respectively. The difference between groups 1Cha and 2Cha is unreliable (p= 0.476), which indicates the effectiveness of adhesion of various adhesives. In the samples of teeth of the chewing group, the adhesive strength after thermal cycling in groups 1Chb and 2Chb amounted to 3479.5(2708.8; 3995.6) N and 1999.0 (1646.3; 3120.8) N, respectively. The difference between them is unreliable (p=0.153), which confirms the effectiveness of adhesion and the safety of the restoration-tooth complex. CONCLUSIONS: The chewing group of teeth can withstand a heavy load in comparison with the teeth of the frontal group. In all groups, there is a decrease in the strength of the joint after thermal cycling. This is due not only to the type of adhesive system, but also to the features of the anatomical structure of the teeth of the chewing group, their shape, area, and surface relief.