One of the fundamental causes of periodontal disease is accumulation of bacterial plaque and calculus and most effective method of removing these plaque and calculus are scaling and root planning using hand curet and ultrasonic scaler. Many studies concerning residual degenerated mineral content after periodontal therapies have been carried out, but some problems about these studies were also known. This research studies mineral concents and distribution of residual root surfaces after perfoming hand curet and ultrasonic scaler on root surfaces of single rooted teeth which were extracted for periodontal reasons. EPMA were used to avoid errors from chemical quantative analysis and in addition SEM observation was also performed.

The results were as follows.

1. No differences were found between curet group andultrasonic scaler group in Ca, P, Mg and Na level.

2. Concentration level was decreased in the sequence of Ca, P, Mg and Na.

3. Ca and P level were decreased as going to apical portion at curet group and ultrasonic scaler group.

4. More cementum was removed at cervical portion compared to other portion at curet group and ultrasonic scaler group.

5. Ca, P, Mg level was higher in dentin compared to cememtum.

There was no difference in mineral level for Ca, P, Mg and Na between root surfaces treated with hand curet and ultrasonic scaler.