Bond strength of adhesive systems to dentin and enamel—Human vs. bovine primary teeth in vitro

Objectives This in vitro study compared the bonding performance of four adhesive luting agents to dentin and enamel of human and bovine primary teeth, in order to evaluate the suitability of primary bovine hard tissues for replacement of those of human origin for bond testing. Methods A composite (Clearfil AP-X) was bonded to specimens from 167 extracted human (n = 88) and bovine (n = 88) primary teeth using the following adhesive systems: Syntac Assortment (SY), Adaper Prompt L-Pop (PLP), iBond Gluma inside (IB) and Clearfil Protect Bond (PB). After 24 h storage in distilled water, shear bond strength was determined according to ISO/TS 11405:2003. The data (n = 11 per group) were statistically analyzed with the Mann–Whitney U-test and the error-rates method (ERM). The fracture modes were analyzed with the χ2-test. Results Bond strength data (ERM) and fracture modes (χ2-test) using human primary teeth were, in general, not statistically different from those of bovine origin. With few exceptions, pair wise comparisons showed the same results. The bond strength data for SY, PLP and PB bonded to primary human and bovine enamel were higher than those to primary human and bovine dentin, for IB vice versa. Significance Bovine teeth may be considered as a suitable alternative to human teeth in bond strength tests for primary dentition.