Saliva contamination and resin micromorphological adaptation to cavity walls using single-bottle adhesives

Purpose: To examine and compare the effect of saliva contamination on the resin micromorpholgic adaptation of four single-bottle adhesives. Materials and Methods: Prime & Bond 2.1, One-Step, Tenure Quik with fluoride and Syntac Single Component adhesives were evaluated. Sixty sound molars were divided into three subgroups for each of the four adhesives; Class V cavities were prepared with gingival margins at cementum. Each adhesive was tested under: Normal conditions (Group 1), contamination of the cavity with fresh whole saliva for 20 seconds and removing the excess (Group 2), and contamination of the cavity with fresh whole saliva for 20 seconds and rinsing the saliva for 20 seconds before adhesive application (Group 3). After curing the adhesive, the cavities were filled with Z100 composite, fixed in 2.0% glutaraldehyde and sectioned into two halves. The sectioned halves were fixed again and rinsed with 0.2 M sodium cacodylate buffer. The cut surfaces were wet ground, polished and sonicated in distilled water. The specimens were immersed in decalcifying solution, deprotenized, serially dehydrated, mounted on aluminum stubs, sputter coated and examined under the SEM. Results: The four adhesives formed hybrid layer with resin tags penetration into the dentin. P & B 2.1 showed usually funnel-shaped resin tags; One-Step, cylindrical shape; Tenure Quik and Syntac SC, variable shapes. Saliva contamination did not prevent hybrid layer formation or resin penetration into the dentin tubules. Only Syntac SC displayed a relatively thin hybrid layer with the unwashed saliva-contaminated group.