Enhancing bond strength on demineralized dentin by pre-treatment with selective remineralising agents

Bonding to demineralized dentin of a diseased tooth has shown to be a significant clinical issue. This study evaluated the effect of 0.2% NaF-(NaF), MI Paste™-(CPP-ACP) and the self-assembling peptide 'P11−4′ (Ace-QQRFEWEFEQQ-NH2) contained in Curodont™ Repair, have on microtensile bond strength-(µTBS) of two different adhesive systems (Adper™ Single Bond-(SB) or Clearfil™ SE Bond (CSE)) and wettability of demineralized dentin slices after remineralising agents were applied. The highest µTBS were found for the demineralized dentin-(DD) treated with CPP-ACP; both adhesives systems (p < 0.05) did not significantly difference from P11-4 treatment associated with SB, and also presented higher values than sound dentin-(SD/SB) (p < 0.01). DD treated with P11−4 associated with CSE did not differ from DD/CSE (p > 0.05). The NaF treatment associated with CSE recovered the bond strength values of SD/CSE and associated with CSE demonstrated lower µTBS than other groups, although significantly higher than DD (p < 0.05). P11−4 and CPP-ACP increased significantly the wettability of demineralized dentin (p < 0.05); etching acid improved wettability for all groups (p < 0.05), whilst NaF did not affect the wettability of demineralized dentin (p > 0.05). Morphological analysis of the dentin surface and dentin-resin interface revealed unique features of the applied remineralizing agent. The results indicated that self-assembling peptide P11−4 associated with SB and CPP-ACP associated with SB or CSE significantly enhanced the bond strength to demineralized dentin (p < 0.05). We conclude that by modifying the dentine surface and restoring conditions found on sound dentin, this can enhance the interfacial bonding.