• The Journal of the Korean dental association
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• v.41 no.9 s.412
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• pp.631-636
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• 2003

Bacteria play a major role in the etiology of apical periodontitis. Traditionally it has been held the microorganisms are present in necrotic tissue in the root canal system and in tubules of the root dentin whereas the periapical tissues are free of bacteria. However, it is reported the presence of bacterial in the periapical lesions. They may form the biofilm and survive in the periapical tissues. Especially high incidence of biofilm is reported in the refractory periapical lesions. treatment was presented in the left maxillary first premolar with a long-standing fistula and apical calculus. Also. the role of biofilm and its treatment were discussed.

• Journal of Periodontal and Implant Science
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• v.27 no.3
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• pp.621-631
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• 1997

To verify the effect of subgingival calculus on the periodontal tissues in periodontitis and the effectiveness of supragingival scaling to remove the calculus, 30 teeth from healthy group (Probing pocket depth:$PPD{\leq}mm$: HP group), 15 teeth from moderate group ($4{\leq}PD<7mm$:MP group), 30 teeth from advanced group (PPD>7mm: AP group) were selected and supragingival scaling was performed before extraction of all experimental teeth. After careful extraction, the teeth were cleaned with saline and disclosed with toluidine blue and carefully examined the relationship and distance between the calculus attached on the root surface and periodontal tissues. As a result, it was; 1. The calculus was not discovered on the root surface of teeth in HP group, but was in MP and AP group, mostly on interproximal surface and furca area. The shape of the attached calculus was ovoid, trepazoid and polygonal and the calculus was distributed randomly over the root surface. 2. PPD was more than the distance between the gingival margin to the level of attached connective tissue in AP group rather than in HP and MP group. 3. The length of calculus was $2.7mm{\pm}.44mm$ in HP group and $4.1{\pm}.89in$ AP group. 4. The distance between the apical margin of calculus and the level of attached connective tissue was $2.4{\pm}.33mm$ in MP group and $3.4{\pm}.89mm$ in AP group. 5. The length of subgingival calculus was tended to increase in relation to the probing pocket depth. Therefore, it can be concluded, the calculus in periodontal pocket can not be removed completely with supragingival scaling. As the terminal part of calculus was far away with limited distance from the periodontal tissue, it can be said that the calculus was not a direct factor in destroying the periodontal tissue. In this study, the extent of the plaque was not verified but the location of calculus can be used in clinical practice for complete removal of calculus when the distance relation bewteen calculus and plaque will be known.

• Journal of Periodontal and Implant Science
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• v.29 no.2
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• pp.387-400
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• 1999

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.

• The Journal of the Korean dental association
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• v.19 no.7 s.146
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• pp.625-634
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• 1981

A Scanning Electron Microscopic Study of the root surface changes was carried out in advanced periodontal disease. The results obtained were summerized as follow; 1. The root surface of cementoenamel junction of healthy root showed smooth surface, while the root surface of diseased state showed covering of deposits which regareded as a course of calcification. 2. At the mid-portion of the root, the regular cemental projection were observed on the healthy root surface and on the root surface of diseased state, cemental projection showed relatively irregular pattern. 3. On the root surface which consist of wall of periodontal pocket, there were various deposits which could be considered as subgingival calculus, bacterial plaque and epithelial attachment remnant. 4. The bottom area of the pathologic pocket, tearing altered collagen fibers were seen on the root surface. 5. At the apical portion of root surface, calcified fibers ran parallel to the root surface in healthy tooth and the fiber bundles of periodontal ligament were seen in the diseased state.