• Journal of Periodontal and Implant Science
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• 제39권3호
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• pp.303-310
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• 2009

Purpose: The aerosol generated by ultrasonic scaler can contain bacteria or virus which can penetrate into body through respiratory systems of dentists, dental hygienist or patients. The aim of this study is to evaluate the effect of chlorhexidine digluconate as preoperative mouthrinse or lavage for ultrasonic scaler on the reduction of viable organisms in aerosol produced during periodontal treatment using ultrasonic scaler. Methods: 30 patients with moderate chronic periodontitis were included and divided into 3 groups: Control (no preoperative mouthrinse and tap water as lavage), CHG (preoperative mouthrinse with 0.1% chlorhexidine digluconate and tap water as lavage), CHL (no preoperative mouthrinse and 0.1% chlorhexidine digluconate as lavage). Each patient received scaling or subgingival curettage for 30 min. In CHG group, mouthrinse with chlorhexidine digluconate was performed for 1 min. before treatment. Before, during and after scaling or subgingival curettage, air sampling was performed for 7 min. each (1000 L/7 min.) with trypticase-soy agar plate. Agar plates were incubated in $37^{\circ}C$ aerobically. The numbers of colony-forming units (CFU) were counted and compared. Results: The numbers of CFUs of the samples obtained during treatment were $97{\pm}14.0$ in control, $73.1{\pm}14.9$ in CHG group and $44.5{\pm}9.0$ in CHL group. The difference among the 3 groups was determined to be statistically significant (one-way ANOVA with Bonferroni's correction, p-value: 0.0003). In contrast, the numbers of CFU of samples obtained before and after treatment were not significantly different among the groups. Conclusions: Chlorhexidine digluconate used as preoperative mouthrinse or lavage for ultrasonic scaler can reduce the microorganisms in aerosol produced during periodontal treatment using ultrasonic scaler. Less number of microorganisms were detected when chlorhexidine was used as lavage for ultrasonic scaler.

• 대한치주과학회:학술대회논문집
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• 대한치주과학회 2007년도 제47회 종합학술대회 연제초록
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• pp.58-58
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• 2007

• 한국기계가공학회지
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• 제15권1호
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• pp.1-7
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• 2016

In the dentistry field, an ultrasonic surgery unit is widely used in bone cutting and scaling to reduce operation time and minimize hemorrhage. The purpose of this study was to evaluate bone cutting and the effect of a specimen's temperature on the two-type ultrasonic surgery unit using a handpiece moving system(HMS). A HMS, which can cut the bone, was developed to perform the experimental procedure with precision of motion control. Bone specimens were prepared from a combination of epoxy-hardener and cortical bone of bovine leg. Through the bone-cutting experiment, the cutting depth was evaluated by not only scanning electron microscopy, but also Vernier calipers. Also, the temperature distribution was measured by a thermo-graphic camera. This study may be applied methodically in various experimental evaluations on a performance test by a HMS.

• Journal of Periodontal and Implant Science
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• 제29권2호
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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.

• Journal of Periodontal and Implant Science
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• 제42권3호
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• pp.88-94
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• 2012

Purpose: The use of appropriate instruments to clean surfaces with minimal change, is critical for the successful maintenance of a dental implant. However, there is no consensus about the type and methodology for such instruments. The aim of this study was to characterize changes in the roughness of titanium surfaces treated by various scaling instruments. Methods: Thirty-seven identical disks (5 mm in diameter) were investigated in this study. The specimens were divided into eight groups according to the types of instrumentation and the angle of application. Ultrasonic scaling systems were applied on a titanium disk to simulate standard clinical conditions. The equipment included a piezoelectric ultrasonic scaler with a newly developed metallic tip (NS group), a piezoelectric ultrasonic scaler with a conventional tip (CS group), a piezoelectric root planer ultrasonic scaler with a conventional tip (PR group), and a plastic hand curette (PH group). In addition, the sites treated using piezoelectric ultrasonic scaler systems were divided two sub-groups: 15 and 45 degrees. The treated titanium surfaces were observed by scanning electron microscopy (SEM), and the average surface roughness (Ra) and mean roughness profile depth (Rz) were measured with a profilometer. Results: SEM no significant changes in the titanium surfaces in the NS group, regardless of the angle of application. The PH group also showed no marked changes to the titanium surface, although some smoothening was observed. All CS and PR sites lost their original texture and showed irregular surfaces in SEM analysis. The profilometer analysis demonstrated that the roughness values (Ra and Rz) of the titanium surfaces increased in all, except the PH and NS groups, which showed roughness decreases relative to the untreated control group. The Ra value differed significantly between the NS and PR groups (P<0.05). Conclusions: The results of this study indicated that changes in or damage to titanium surfaces might be more affected by the hardness of the scaler tip than by the application method. Within the limitations of this study, the newly developed metallic scaler tip might be especially suitable for peri-implant surface decontamination, due to its limited effects on the titanium surface.

• Coupled systems mechanics
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• 제10권1호
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• pp.39-60
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• 2021

The present paper is concerned with the study of nonlinear ultrasonic waves in a magneto thermo (MT) elastic armchair single-walled carbon nanotube (ASWCNT) resting on polymer matrix. The analytical formulation is developed based on Eringen's nonlocal elasticity theory to account small scale effect. After developing the formal solution of the mathematical model consisting of partial differential equations, the frequency equations have been analyzed numerically by using the nonlinear foundations supported by Winkler-Pasternak model. The solution is obtained by ultrasonic wave dispersion relations. Parametric work is carried out to scrutinize the influence of the non local scaling, magneto-mechanical loadings, foundation parameters, various boundary condition and length on the dimensionless frequency of nanotube. It is noticed that the boundary conditions, nonlocal parameter, and tube geometrical parameters have significant effects on dimensionless frequency of nano tubes. The results presented in this study can provide mechanism for the study and design of the nano devices like component of nano oscillators, micro wave absorbing, nano-electron technology and nano-electro- magneto-mechanical systems (NEMMS) that make use of the wave propagation properties of armchair single-walled carbon nanotubes embedded on polymer matrix.

• Journal of Periodontal and Implant Science
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• 제42권6호
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• pp.243-247
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• 2012

Purpose: The effects of magnetostrictive and piezoelectric devices on tooth surfaces seem to differ with regard to the root surface roughness they produce. This study aimed to compare the results of scaling using magnetostrictive and piezoelectric devices on extracted teeth. Methods: Forty-four human extracted teeth were assigned to four study groups (n=11). In two groups (C100 and C200), the teeth were scaled using a magnetostrictive device and two different lateral forces: 100 g and 200 g, respectively. In the other two groups (P100 and P200), the teeth were scaled with a piezoelectric device with 100 g and 200 g of lateral force, respectively. The teeth were scaled and the data on the duration of scaling and the amount of surface were collected and analyzed using the t-test. Results: The mean time needed for instrumentation for the piezoelectric and magnetostrictive devices was 50:54 and 41:10, respectively, but their difference was not statistically significant (P=0.171). For root surface roughness, we only found a statistically significantly poorer result for the C200 group in comparison to the P200 group (P=0.033). Conclusions: This study revealed that applying a piezoelectric scaler with 200 g of lateral force leaves smoother surfaces than a magnetostrictive device with the same lateral force.

• 보존과학회지
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• 제34권3호
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• pp.167-177
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• 2018

캄보디아 앙코르 보존소에 소재하는 관음보살은 13세기 바이욘 양식의 석상으로, 중립의 장석질 잡사암으로 조성되었으며 석재 표면에 형성된 담갈색 풍화면에서는 방해석이 관찰되었다. 석상의 상태평가 결과, 박리와 균열의 중첩발생으로 인한 파편화 및 박락으로 인한 물리적 훼손이 심각하였다. 특히 물리적 훼손부 및 주변은 초음파속도가 낮아 입자의 결합력을 향상시킬 수 있는 보존처리가 필요한 상태였다. 이에 따라 석상의 보존환경을 고려한 염풍화의 방재 및 물리적 안정성 확보를 위하여 에틸 실리케이트계 강화제 및 석재와 유사성분의 석분을 배합하여 충전하고 노후된 보수물질을 교체하였다.

• Journal of Periodontal and Implant Science
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• 제43권6호
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• pp.301-307
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• 2013

Purpose: This in vitro study was performed to assess the adherence of Porphyromonas gingivalis to a resorbable blast media (RBM) titanium surface pretreated with an ultrasonic scaler or toothbrush and to evaluate the effects of the treatment of the RBM titanium discs on the bacterial removal efficiency of brushing by crystal violet assay and scanning electron microscopy. Methods: RBM titanium discs were pretreated with one of several ultrasonic scaler tips or cleaned with a toothbrush. Then the titanium discs were incubated with P. gingivalis and the quantity of adherent bacteria was compared. The disc surfaces incubated with bacteria were brushed with a toothbrush with dentifrice. Bacteria remaining on the disc surfaces were quantified. Results: A change in morphology of the surface of the RBM titanium discs after different treatments was noted. There were no significant differences in the adherence of bacteria on the pretreated discs according to the treatment modality. Pretreatment with various instruments did not produce significant differences in the bacterial removal efficiency of brushing with dentifrice. Conclusions: Within the limits of this study, various types of mechanical instrumentation were shown to cause mechanical changes on the RBM titanium surface but did not show a significant influence on the adherence of bacteria and removal efficiency of brushing.

• Journal of Periodontal and Implant Science
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• 제35권4호
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• pp.1109-1116
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• 2005

The purpose of this study was to observe the effects of periodontal therapy, including nonsurgical periodontal therapy with azithromycin, surgical therapy, and maintenace therapy on the drug-induced gingival enlargement, by means of measuring gingival thickness. The test group of 18 patients with drug-induced gingival enlargement received scaling, root planing with azithromycin for 5 days, with or without surgical periodontal treatment. The control group of 18 patients who had not taken any medication, received scaling and root planing, with or without surgical periodontal treatment. Both groups received supportive periodontal therapy every 3 months for 2 years. The mean period of total treatment is 32 months in the test group and 31 months in the control group. The thickness of the buccal gingiva was measured using an ultrasonic device of $SDM^{(R)}$(Krupp Corp., Essen, Germany). The results revealed that the test $group(1.21{\pm}0.51mm)$ showed statistically thicker buccal gingiva than the control $group(1.01{\pm}0.3mm)$. In the test group, the buccal gingiva was thickest on 2nd molars and was thinnest on canines of both dental arches. In the control group, the buccal gingiva was thickest on central incisors in the maxilla and 2nd molars in the mandible, while the thinnest areas were on canines in the maxilla and 1st premolars in the mandible. It would be concluded that the periodontal treatment with azithromycin aids in decreasing the degree of the gingival enlargement but cannot prevent the recurrence completely.