RESUMO
Statement of the Problem: There are some concerns regarding the effect of Chlorhexidine [CHX] applied for cavity disinfection on the bond strength of adhesive restorations to dentin
Purpose: This study sought to assess the effect of CHX on the shear strength [SBS] of Equia resin-modified glass ionomer cement [RMGIC] to dentin in permanent teeth
Materials and Method: In this experimental study, the buccal surface of 84 freshly extracted human premolars was ground to expose the flat dentin. The samples were randomly assigned to four groups [n=21]. The steps were as following in the group I[a]: conditioning, Equia RMGIC, 500 thermal cycles; group Ib: conditioning, Equia RMGIC, 6000 thermal cycles; group II[a]: conditioning, CHX, Equia RMGIC, 500 thermal cycles, and group II[b]: conditioning, CHX, Equia RMGIC, and 6000 thermal cycles. Twenty samples from each group were subjected to SBS test and one sample was inspected under a scanning electron microscope. Data were analyzed using two-way ANOVA and t-test
Results: The SBS was significantly different among the groups [p= 0.007]. The groups subjected to 500 thermal cycles showed significantly higher SBS to dentin when they were treated with CHX [p= 0.000]. There was no significant difference between samples thermocycled for 6000 cycles with and without application of CHX [p= 0.269]
The SBS in the groups that were thermocycled for 6000 cycles [I[b] and II[b]] was lower than those thermocycled for 500 cycles [I[a] and II[a]]. This difference between II[a] and lib was statistically significant [p= 0.007]
Conclusion: Chlorhexidine can positively affect the short term SBS of Equia RMGIC to dentin