Effect of a Resin Coating on Prevention of Root Caries

Objectives: The aim of this study was to evaluate the effect of a resin coating using the self-etching primer adhesive systems; Clearfil SE Bond (SE), Clearfil Tri-S Bond (TB, Kuraray Medical, Japan), G- Bond (GB, GC, Japan) and Hybrid Bond (HB, Sun Medical, Japan) on prevention of root surface caries.

Method: Twenty-one roots of human premolars were ground with #600 SiC to flatten the dentin surface. For root surface coating, a single coat of the adhesive system was applied on the root surface and light cured in SE, TB and GB, while a single/double coat of HB was applied on the dentin surface. The root dentin surface without resin coating was used as a control. The specimens were then stored in water for 1day. In addition, they were stored in an artificial demineralizing solution adjusted at pH4.5 for 3.5 days. They were then sectioned into two halves along to the long axis of the root and polished down to 0.25 ìm with a diamond paste. Depth of thedemineralization of the root dentin was examined for each specimen using a comfocal laser scanning microscopy (1LM21, Elionix, Tokyo, Japan) and nano-indentation(ENT-1100,Elionix,Tokyo,Japan).

Results: Thick demineralization (215.5±2.5µm ) was created at the underlying dentin in the control group, while demineralization was limited in a single coating of HB (42.7±1.1µm). However, the demineralization was completely prevented in a single coat of SB, TB and GB, and a double coat of HB. Conclusion: The resin coating on root surface using the self-etching primer adhesive systems demonstrated good potential to prevent root dentin caries.

Key Words: resin coating, root dentin caries, CLSM, Nano-indentation