Comparison of tensile failure load of composite restorations in class III cavities of primary anterior teeth with different preparation techniqes (conventional, air - abrasion and labial surface level)

Abstract

Cl III restorations in anterior primary teeth have limited durability due to poor retention of the composite material. Aim.To compare the effect of air abrasion on tensile failure load of composite restorations in different preparation techniques in class III cavities of anterior primary teeth. Design. 100 extracted human anterior primary teeth were divided into four groups of 25 each on the basis of the method of preparations: conventional (A), labial surface bevel (B), conventional + air abrasion (C), and labial surface bevel + air abrasion (D). After restoring cavities, tensile failure load of samples was measured in Newton by Universal testing machine at a crosshead speed of 1 mm per minute. The data were analyzed by Kruskal-Wallis and Mann Whitney U tests using SPSS software. Results. There were statistically significant differences between groups A and C (P = 0.003), groups A and B (P < 0.001), groups A and D (P < 0.001), groups B and C (P = 0.028), groups B and D (P = 0.027) and also groups C, D (P < 0.001). Group D demonstrated highest mean tensile failure load. Conclusions. Labial surface bevel treated by air abrasion showed more retention of composite resin in anterior primary teeth.