Abstract
Fourty Class 1 and Class 5 cavities were made on extracted primary teeth using the air-powder abrasive system KCP-2001J.
For the purpose of observing the outline form and detailof the cavity, replicas of the cavities were made using composite resins with or without etching, primer and bonding agent, The replica was observed by SEM.
The following conclusions were obtained.
1. The Replicas of the air-powder prepared cavities, showed the following characteristics, a slight rounded carvo-surface margin and a smooth cavity wall, without a distinct line angle on the cavity wall to the cavity floor. No smear layer was observed on the cavity floor.
2. Two types of outline form of the replica were observed, with one peak on the central portion of the cavity floor and with two peaks on the mesial and distal portion of the cavity floor.
3. In the experimental group with the primer and bonding agent, penetration of resin into the dentinal tubles was observed in detail.
4. In the experimental group with the etching agent, resin tags were observed on the carvo-surface enamel. Rather long resin penetration into the dentinal tubles was also observed in detail on the cavity floor.
5. Etching of the cavity is considered also useful for the adheasion of resin to enamel and dentin even in air-powder abrasive cavity preparation.
