Microtensile Bond Strength of Three Different Adhesive Systems to Primary Enamel: An In Vitro Study

The purpose of this in vitro study was to assess and compare the microtensile bond strength of three adhesive systems to primary enamel. This laboratory study involved the preparation of 16 primary molars, randomly distributed over three groups, using the following adhesive systems: GI-Prime&Bond^® XP (PBXP); GII-Clearfil™ SE Protect Bond (CSEPB); and GIII-Clearfil™ S3Bond Plus (CSB). After applying each adhesive system on enamel as recommended, Ceram. X™ Universal composite blocks were built. Samples were then cross-sectioned into quadrangular test specimens and subjected to microtensile tests. Fracture patterns were classified by optical microscopy examination. Statistical analysis was performed using IBM SPSS 24.0 software (five percent significance level). PBXP showed statistically higher levels of microtensile adhesion than CSEPB and CSB, which, in turn, did not significantly differ from each other. Fracture patterns observed were, for the majority, adhesive fractures across all groups. There was no statistically significant association between group and type of failures. Bond strength of the etch-rinse adhesive to primary prepared enamel was statistically higher than for the two self-etch systems tested, which, in turn, did not significantly differ from each other.