Abstract
This study was attempted in order to investigate the tooth-adhesive resin penetration into the etched normal and carious primary dentin through a scanning electron microscope. Extracted or exfoliated teeth (noncarious: 84 cases, caries extended into the dentin: 26 cases) were used. Cavities were prepared dry with the diamond bars, softened dentin was removed with the steel bars and a hand instrument. The commercially available resins used in this study were Adaptic, Silar and Clearfil F. The dentin was etched for l minute, then rinsed with water for 30 seconds and desiccated with compressed air for 30 seconds. The following observations were obtained.
1. Using the bonding agents, the length of the resin tags into the carious decayed dentin is shorter than that into the noncarious dentin. Also the length of the resin tags into the carious decayed dentin with bonding agents is almost the same as the resin tags into the noncarious dentin without bonding.
2. The shape differences of the resin tags were variable between noncarious teeth and carious decayed teeth, and also according to various commercially available resins.
3. Clearfil F showed the best penetration into the dentinal tubles.
4. The resin penetration into the carious decayed primary dentin was lower than that into the normal primary dentin
