The long-term consequence of salivary contamination at various stages of adhesive application and clinically feasible remedies to decontaminate

OBJECTIVE To analyse the bond quality in dentine post-ageing after salivary contamination and decontamination at different stages of dental adhesive application. MATERIALS AND METHODS A total of 1120 human dentine specimens were randomly allocated to 14 groups for four intervals (n = 20) to be treated with a self-etching (SE) and universal (U) adhesive. The saliva contamination and decontamination were implemented after surface preparation, after primer application (for SE) and after adhesive curing. The decontamination groups were either rinsed and air-dried or rinsed, air-dried and reapplied with adhesive. They were stored (37°C, distilled water) for four intervals (1 week, 1 month, 3 months and 1 year) and subjected to shear bond strength (SBS) test at a crosshead speed of 0.5 mm/min. RESULT One-way ANOVA with Tukey’s test (α = 0.05) revealed significant reduction in SBS in all the groups in U adhesive compared with the control group at 1 week (p < 0.0001) and in SE when the contamination took place after primer application. However, decontamination improved the SBS in SE but not in U adhesive. The univariate analysis confirmed significant influences (p < 0.0001) seen by treatment procedure (η2p=0.075), type of adhesive (η2p = 0.328), ageing (η2p = 0.13), experimental groups (η2p = 0.518), and the stage of influence (η2p = 0.60). CONCLUSION Saliva contamination is detrimental after primer application in SE but, decontamination regained the SBS and maintained it over time. In U adhesive, SBS deteriorated over time irrespective of the contamination. CLINICAL RELEVANCE Salivary contamination showed different influences on SBS at various stages of restoration with contemporary dental adhesives