• The korean journal of orthodontics
• /
• v.25 no.3 s.50
• /
• pp.235-245
• /
• 1995

The purpose of this paper is to review two recently reported, long-term studies of several chemical methods to control gingivitis and decalcification in adolescent orthodontic patients. The first study(gingivitis study) was designed to determine whether conventional toothbrushing and twice daily use of a brush-on 0.4 per cent $SnF_2$ gel containing more than 90 per cent available $Sn^{2+}$ would be more effective for controlling plaque accumulation and gingivitis in the presence of orthodontic appliances than conventional toothbrushing alone. The second study(decalcification study) was designed to compare the effectiveness of controlling decalcification in orthodontic patients with either a II00 ppm F tooth paste used alone, this same toothpaste and a 0.05 percent NaF rinse or this toothpaste and a 0.4 percent $SnF_2$ gel. In the gingivitis study, sixty-five consecutively treated adolescents who were to receive full-mouth fixed orthodontic appliances were assigned to two groups according to age and sex criteria. In the decalcification study an additional 30 subjects(95 total) were similarly assigned to a third group. The first group(control, n=35) used only toothbrushing with a standard fluoride(1100 ppm F) toothpaste. The second group used toothbrushing with a similar dentifrice supplemented with a 0.4 percent $SnF_2$ gel($SnF_2$ gel group, n=30) used twice daily for the entire 18-month study period. The third group(in the decalcification study only) used a similar toothpaste and 0.05 percent NaF rinse(NgF rinse group, n=30). Clinical assessments of plaque accumulation using the Plaque Index, gingival inflammation using the Gingival Index, and coronal staining were completed single-blinded before appliances were placed and 1, 3, 6, 9, 12 and 18 months after appliances were placed. Decalcification was assessed single blind on all labial surfaces of all erupted teeth before appliances were placed and 3 months after appliances were removed. The results of the gingivitis study indicated that the $SnF_2$ gel gorup had significantly lower scores for the Plaque Index(p<0.01) and Gingival Index(p<0.001) at all examinations during orthodontic treatment than did the control group. In the $SnF_2$ gel group, one subject developed mild coronal staining and two subjects developed moderate staining. In the decalcification study, when pre-treatment levels of decalcification were subtracted from post-treatment values, significantly lower decalcification scores(p<0.05) were found for both whole mouth and first molars in the NaF rinse and gel groups as compared with the control gorup(toothpaste alone). Although the gel group consistently had less decalcification than the rinse group, this difference only approached statistical significance.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.32 no.3
• /
• pp.454-460
• /
• 2005

The purpose of study was to observe the effect of calcium and citric acid on the dental erosion of human premolar enamel. Enamel specimens were demineralized in 0.1%, 0.3%, 0.5%, or 1.0% citric acid solutions with 0.05%, 0.1%, or 0.2% calcium for 5, 15, 30, and 60 minutes, and then the surface microhardness of the enamel was measured. The hardness decreased as the concentration of citric acid and the demineralization time increased. Hardness after 5 minutes was 76~90% in case of no calcium and the inhibition of dental erosion by calcium addition was 2??15%. Hardness after 15 minutes was 65~84% in case of no calcium and the inhibition of dental erosion by calcium addition was 3~17%. Hardness after 30 minutes was 53~72% in case of no calcium and the inhibition of dental erosion by calcium addition was 6~22%. Hardness after 60 minutes was 43~66% in case of no calcium and the inhibition of dental erosion by calcium addition was 7~19%. The inhibition was the highest in 1.0% citric acid and 0.2% calcium. In 0.1% citric acid the inhibition increased as the demineralization time increased, but in 0.3% to 1.0% citric acid the inhibition was most high at 30 minutes and decreased a little at 60 minutes. These results suggest that calcium has a inhibitory effect on the citric acid induced dental erosion.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.27 no.2
• /
• pp.7-13
• /
• 1997

조직학적으로 유용성이 입증된 산탈회법을 이용한 인접면 비교적 초기 치아 우식의 병소를 형성하여 진단율을 조사하였다. 산 용액을 이용하여 20개 인접면 치아우식을 20개 소구치에 형성하였고, 37개 인접면 치아우식을 30개 대구치에 형성하였다. 건전한 소구치 20개, 대구치 30개를 포함하여 총 96개 치아를 4개씩 나누어 24개의 블록을 형성하였고, 각각 2개 블록의 교합면을 교합시켜서, 교익촬영을 하였다. 촬영 결과를 36명의 치과의사들이인접면 치아우식의 유무를 기록하고, 동시에 및 ROC 분석을 위한 5 개 범주의 판독 기준으로 판독하여 기록하였다. 인접면 치아우식증 유, 무만으로 판독한 결과 진단의 sensitivity는 0.71, specificity는 0.78 이였다. ROC 분석 한 결과의 곡선도표 아래부분의 평균 면적은 약 0.806 이였다. 치아우식증 유무만으로 진단한 결과는 특정한 sensitivity와 specificity 만을 나타내지만, ROC 분석 결과는 주관적 진단 기준과 구별되는 고유의 진단 능력을 표시하는 1-specificity(False Positive)의 변화에 따른 sensitivity(True Positive)의 변화를 연속적으로 나타내어 주었다.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.31 no.3
• /
• pp.506-515
• /
• 2004

The objective of this study was to compare the rate of in vitro demineralization of bovine permanent (BP), human deciduous (HD) and human permanent (HP) enamel. Twenty aye flattened and polished enamel samples for each group (BP, HD, HP) were immersed in a demineralizing solution (0.1 mol/L lactic acid, 0.2% Carbopol 907, and 50% saturated hydroxyapatite) for 1, 2, 4 or 8 days. All 25 samples from each group were subjected to Quantitative light induced fluorescence analysis (QLF) and 5 samples from each group were randomly selected for Transverse Microradiography analysis (TMR). Integrated mineral loss (IML) and lesion depth (LD) were determined by TMR. The fluorescence radiance (FR) of sound enamel $(FR_S)$, demineralized enamel $(FR_D)$ were determined by QLF and FR ratio $(FR_D/FR_S)$ was calculated. Bovine enamel samples showed significant correlation between FR ratio and lesion depth(p<0.05) and deciduous enamel samples does not showed significant correlation between FR ratio and lesion depth(p>0.05). Permanent enamel samples showed significant correlation between FR ratio and lesion depth(p<0.05) The constant of demineralization time between FR ratio from regression analysis were as follows: bovine enamel was -4.643(p<0.05) deciduous enamel was -5.421(p<0.05) and permanent enamel was -4.435(p<0.05).

• Journal of the korean academy of Pediatric Dentistry
• /
• v.30 no.2
• /
• pp.320-325
• /
• 2003

The purpose of study was to investigate the effect of carbon dioxide laser on demineralization inhibition and rehardening of primary tooth enamel according to its power and irradiation time. 2mm diameter circle on the primary enamel surface was irradiated by defocused $10.6{\mu}m$ superpulse carbon dioxide laser at 6 Watt 2 seconds or at 3 Watt 8 seconds, before or after demineralization by Coca-Cola for 24 hours. Enamel surface change was measured by the Diagnodent. The results were analyzed with the former study results of 3 Watt 4 seconds and 6 Watt and 4 seconds. Diagnodent scores increased significantly after demineralization of irradiated enamel at 6W 2s or 3W 8s (P<0.05). Among the four groups, only 6W 4s group showed obvious demineralization inhibition effect. Diagnodent scores reduced significantly after 6W 2s or 3W 8s irradiation of demineralized enamel(P<0.05). Among the four groups, 6W 4s showed nearly complete rehardening effect, and the other groups showed partial effect. Tooth discoloration only occurred at 6W 4s. It seemed that caries inhibition and tooth discoloration depend on laser power more than total irradiation energy.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.10 no.9
• /
• pp.2523-2529
• /
• 2009

The purpose of this study was to observe the demineralization effects of children's range beverage on bovine enamel. 15 bovine teeth without dental caries were divided into 4 experimental groups (n=12) and control group (n=3). All samples immersed in beverages maintained 48 hours by $37^{\circ}C$ in incubate respectively. The surface microhardness values(${\Delta}VHN$) between before and after 48 hours treatment decreased and DIGNOdent value increased because enamel surface were corroded by experimentation beverage. Especially, there was statistical significantly difference in the carbonated drink. Morphological changes by scanning electron microscope were indicated that children's range beverage cause significant enamel demineralization effects on bovine tooth surface among five beverages.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.38 no.1
• /
• pp.52-59
• /
• 2022

Decalcification of the buccal surface of the teeth often occurs during fixed orthodontic treatment. This case report describes two cases in which cervical decalcificated teeth that occurred during orthodontic treatment were treated with direct resin veneer restoration. Early lesions without caries can be remineralized through periodic fluoride application, diet control, and oral hygiene improvement. As it progresses, appropriate repair treatment is required, and it is more preferable to focus on prevention rather than treatment after the occurrence of the lesion.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.42 no.3
• /
• pp.218-225
• /
• 2015

This study used sodium fluorescein to improve imaging diagnostic ability by increasing the fluorescence difference between sound enamel and caries lesions. It also made it easier to discriminate between stain and caries lesions using quantitative light-induced fluorescence (QLF). Half of the specimen surface was covered with nail varnish as a control. Specimens were divided randomly in six decalcification groups and decalcified for different lengths of time. Then, ${\Delta}F$ was measured using QLF-D. After applying 0.075% sodium fluorescein, we measured ${\Delta}F$ again and compared it with the initial value. After cutting the central portion of the specimen, we measured the lesion depth using scanning electron microscopy. The lesion surfaces observed with QLF were darker than normal enamel, whereas they were lighter than normal enamel after applying fluorescein. Longer decalcification time was associated with greater fluorescent dye penetration. The ${\Delta}F$ measured after applying fluorescein was higher than the initial value (p < 0.05). Due to QLF measurement using fluorescein being more sensitive for diagnosing early decalcification, this approach will enable early diagnosis of dental caries before the cavity formation stage, allowing the treatment of early caries lesions. With QLF and sodium fluorescein, we can easily discriminate between stain and caries lesions.

• The korean journal of orthodontics
• /
• v.26 no.1 s.54
• /
• pp.17-32
• /
• 1996

It is important to understand the operating mechanism and force system of fixed appliance that most effective for individual tooth movement in various orthodontic appliances. The archwire system of fixed appliance is devided into 3 types, which is continuous arch, segmented arch and sectional arch. The last two types have longer interbracket distance and simple force operating points, so it is easy to control force system by operator. But the continuous arch has shorter interbracket distance and various bracket geometry, so it is hard to control and anaylze the force system. The purpose of this study was three dimentional force and moment analysis of continuous arch system by finite element method, which is similar situation to three dimentional elastic beam in structural engineering. Several sample form of various bracket geometry and artificial lower crowding typodont made by author were constructed, analyzed and compared each other. The results were as follows : 1. The force magnitude is linear proportional to the degree of displacement or tilting of the bracket. 2. The force magnitude is inversely non-linear proportional to the interbracket distance. 3. In three dimensional typodont model, while the force can be compared with that of the sample form in the area where adjacent bracket geometry is simple, the force is much more than the expected value in the area where adjacent bracket geometry is complex.

• Proceedings of the KACD Conference
• /
• 2003.05a
• /
• pp.290-290
• /
• 2003

지난 20세기 동안, 치아 우식에 대한 치료는 G.V. Black이 제안한 '예방 확대' 개념에 따른 와동형성 원칙에 따라 외과적 치칠 삭제의 형태로 수행되어져 왔다. 즉, 치아 우식 병소에 발견되면 치과의사들은 망설임 없이 핸드 피스를 들고 우식 부위 치질을 삭제하며, 수복재료에 따라 적합한 형태로 건전한 치질을 삭제하여 수복 와동을 형성하였다. 그러나 치아 우식에 대한 많은 연구 결과, 원인균과 산 생산 및 탈회와 재석회화 등에 대한 정보가 알려졌고, 접착 수복이 비약적 발전을 하여 임상 적용이 일반화되면서, 지난 10여년 이래 치아 우식에 대한 치료 개념이 점차 최소 치질 삭제와 건전 치질 보존으로 전환되어 왔고 이러한 개념을 통칭하여 Minimal Intervention Dentistry라 하고 있다. 21세기에는 치아 우식에 대한 치료가 minimal intervention dentistry의 개념 하에 점차 폭넓게 임상에 적용될 것으로 예상되며, 다음과 같은 원칙들이 제시되고 있다.(중략)