Effects of calcium-containing desensitizers on the bonding stability of an etch-and-rinse adhesive against long-term water storage and pH cycling

This study aimed to evaluate the effects of two calcium-containing desensitizing pastes on the bonding stability of an etch-and-rinse (E&R) adhesive to dentine. After dentine hypersensitivity model established, dentine surfaces were assigned one of the following pretreatment: Group 1, no desensitizer; Group 2, CPP-ACP; and Group 3, Novamin. Specimens were then bonded with an E&R adhesive. Beams from each tooth were randomly divided into three subgroups and then subjected to microtensile bond strength (MTBS) test after 24 h; 12 months of water storage; or 15 runs of pH cycling. Failure modes, nanoleakage, and tubule-occluding effectiveness were analyzed. Results showed that CPP-ACP- or Novamin-pretreated specimens mainly preserved the bonding strength after 12 months of water storage, while effective tubule occlusion could be observed. The results suggested that the calcium containing desensitizers were compatible pretreatment for bonding with E&R adhesives to obtain reliable long-term bonding strength and prevention of post-operative sensitivity.