Permeability of Modified Dentinal Surfaces

Objectives: The aim of this study was to investigate the sealing ability of three adhesives bonded to modified dentinal surfaces after short and long storage periods. Methods: Three adhesives were used in this study; two-step etch-and-rinse “Adper Single Bond 2”, two-step self-etch “AdheSE” and one-step self-etch “G-Bond” adhesives. Modifications of the dentinal surface was performed by application of adhesives after oxalate application, application of adhesive after oxalate application to sodium hypochlorite (NaOCl)-deproteinized dentinal surface, compared to control groups (application of adhesive without any surface pretreatment). Dentinal sealing was investigated by measuring dentin permeability, using a fluid transport apparatus, after two storage periods; 24 hours and 2 months. Results: After 24 hours, the control group bonded with “Adper Single Bond 2” without any surface treatment had the highest permeability (25.3%) followed by “G-Bond” (16.2%) and finally “AdheSE” (11%). Significant reductions in permeability values were observed on application of oxalate in conjunction with both “Adper Single Bond 2” and “AdheSE” (11.7% and 2.6% respectively). Further significant reductions in permeability values of those two adhesives were noted when the combined NaOCl and oxalate pretreatments were used (5.7% and 0.8% respectively). Permeability means for all groups increased after storage for 2 months. Conclusions: Dentin surface deproteinization plus oxalate application produced the best dentin sealing for two step adhesives. Key words: Etch-and-rinse adhesives, self-etching adhesives, oxalate-desensitizing agent, NaOCl-deproteinizing agent, dentin permeability.