Method: 16 non-caries mandibular third molar teeth were selected. Crowns of the teeth were ground flat to expose pulp chamber. The teeth were cut bucco-lingually equal in two pieces. These pieces were divided into two groups. Group 1 included distal and Group 2 included mesial halves of the teeth. Group 1 was filled with wax until the remaining depth of pulp chamber was 4 mm and group 2 was filled with wax till the depth was 2mm. These groups were divided into two subgroups (n=8) carefully. Subgroups are treated respectively with self-etch (Clearfil SE Bond) and total-etch (Scotchbond XT) adhesives. Pulp chambers were restorated with a packable composite resin (Filtek Z250) incrementally. The level of composite restorations were finished 2 mm above the occlusal surface. Specimens were embedded in acrylic blocks and kept in 100% humidity for 24 hours. Each specimen was submitted to the microshear test device and 1 mm/min crosshead speed was aplied until seperations were occured. The data was recorded, calculated as MPa and was statistically analyzed using kolmogorov-simirniv normality test and the non parametric data were analyzed using Mann-Whitney U test with bonferroni correction.
Result: Self etched group which had 4mm pulp chamber in depth showed the highest shear bond strength. Significant difference was found between the total etched group which had 2mm pulp chamber in depth and self-etched group which had 4 mm pulp chamber in depth (p<0.05).
Conclusion: In the limitation of this in vitro study, it could be claimed that deeper pulp chambers are needed for better resistance.