Effect of Cavity Dimentions with the Same C-Factor on Micro Leakage of Composite Resin Cavities

Abstract Background and aim: Given the prevalence of microleakage in composites and their known complications and lack of reporting of the influence of cavity depth and diameter on the same c-factor on the microleakage of composite cavities, this study investigated the effect of microleakage on composite cavities in identical C Factors. Materials and Methods: In this experimental study on 40 specimen (4 group of 10 each ) Cylindrical cavities with different volumes were prepared using diamond bur no. 006 in buccal surface of teeth (c-factor = 5). Height and width of cavities, respectively: Group I: Height and diameter 2 mm. groupII: height 2 and diameter 4 mm. Group III: height 4 and diameter 2 mm. Group IV: height and diameter 4 mm. All teeth were then restored with the same procedure. The specimens were then placed in a thermocyclic machine.The microleakage was  evaluated using 50% weight silver nitrate findings were statishtically evaluated with kruscallwallis test considering significant level of 0.05. Result: There was no significant difference between Gingival leakages in 4 groups (p = 0.163). There was a significant difference between 4 groups in occlusal leakage and groups 1 with 2, 2 with 3 and 2 with 4 revealed differences significantly.(P=0.019) Comparing gingival and occlusal microleakage between groups 1,3,4. :there was not significant difference. (P>0.05)  Group 2, there was significant difference between occlusal and gingival microleakage at p = 0.004 and gingival leakage rate was significantly greater than occlusal leakage. (P<0.05) Conclusion: There was no significant direct correlation between C- factor and microleakage, but it seems, microleakage was increased with increasing the cavity dimention.