An evaluation and comparison of shear bond strength of composite resin to dentin, using newer dentin bonding agents

The purpose of this study was to assess the shear bond strength of Total etch Prime and Bond NT and self etch newer dentin bonding agents Clearfil S3, Xeno III Bond, Clearfil Protect Bond and G Bond used to bond composite resin to dentin, and to compare the difference in the shear bond strengths of the self etch newer dentin bonding agents. Hundred freshly extracted noncarious human maxillary premolar teeth were selected. The occlusal surfaces of each tooth were ground to prepare flat dentin surfaces at a depth of 1.5 mm and were randomly grouped, with twenty specimens in each: Group I - Prime and Bond NT, Group II - Clearfil Protect Bond, Group III - Xeno III Bond, Group IV - Clearfil S3 Bond, Group V - G Bond. Each group was treated with its respective bonding agents, as per the manufacturers' instructions Clearfill – Kuraray, Japan, G bond – GC Tokyo, Japan, Xeno- De Trey Densply, Germany. Blocks or Cylinders of composite resin were built up using Teflon mold and cured. Shear bond strengths were tested using Instron Universal testing machine and recorded in Mpa. The results were statistically analyzed using One-way anova and Tukeys HSD test. The total etch adhesive showed higher shear bond strength than self etching adhesives (P < 0.001). Within the limitations of this in vitro study, it can be concluded that all the adhesive agents evaluated showed optimal shear bond strength 17-20 Mpa, except G bond. However, shear bond strength of composite resin to dentin is better with one bottle total etch adhesive than with the newer self etching bonding agents.