• Journal of Periodontal and Implant Science
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• 제32권2호
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• pp.371-378
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• 2002

이번 연구에서는 19명 환자의 40개 상아질 지각과민 치아를 조사하였다. 지각과민증을 평가하기 위하여 기계, 온도 및 전기적 자극을 사용하였다. 상아질 지각과민증의 치료제로는 Gluma(R) Desensitizer (Heraeus Kulzer GmbH & Co., Germany)를 사용 하였다. 연구 방법은 다음과 같다: 지각과민증의 치료 전에 협면의 치관 $\frac{1}{3}$ 부위에서 전기치수검사를 시행하여 치수 생활력을 조사하였고, 그 측정치를 기록하였다. 그리고 기계 및 온도 자극을 이용한 검사를 시행하여 지각과민증의 유무를 확인하였다. 지각과민증이 존재함을 확인한 후에 지각과민증의 마모부에서 전기치수검사를 실시하였다. 치약을 전해질로 사용하였고 반응시의 숫자를 기록하였다. 이후 Gluma(R) Desensitizer를 이용하여 지각과민증을 치료하였다. 치료 후 마모 부위에서 기계, 온도 및 전기 검사를 다시 실시하고 그 결과를 기록하였다. 기계 및 온도 자극에 대해 40개 치아 모두에서 지각과민증 치료 전에는 반응을 보였으며 치료 후에는 반응을 보이지 않았다. 치관 $\frac{1}{3}$ 부위에서 전기치수검사를 실시하였을 때 모든 치아는 31에서 65 (48.9${\pm}$7.2)의 범위에서 반응하였다. 상아질 지각과민증의 치료 전에 전기치수검사를 실시하였을 때 34개의 치아는 2에서 반응하였고 나머지 6개의 치아는 17에서 25 범위에서 반응하였다. 치료 후에는 40개 치아 모두가 12에서 27 (19.6${\pm}$3.5)의 범위에서 반응하였다. 치료 전에 2보다 큰 숫자에서 반응을 보인 여섯개의 치아는 18에서 23의 범위에서 반응하였다. 이번 연구의 범위 내에서 다음과 같은 결론을 도출할 수 있다. 상아질 지각과민증을 보이는 치아가 기계 및 온도 자극에 반응을 보인다면 그 치아는 마모된 면에서 낮은 전기저항을 보인다. 반면 상아질 지각과민증을 치료하여 기계 및 온도 자극에 반응하지 않는다면 그 치아는 마모면에서 증가된 전기저항을 보인다. 전기치수검사는 상아질 지각과민의 진단에 활용될 수 있다. 나아가 전기치수검사는 상아질 지각과민증의 치료 결과를 평가하는 데 유용할 것이다. 하지만 전기치수검사는 상아질 지각과민을 측정하는 데에는 적절하지 못하다.

• Restorative Dentistry and Endodontics
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• 제14권2호
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• pp.65-76
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• 1989

The purpose of this study was to observe the effect on the removal of dentinal smear layer and morphological changes of reduced dentin surfaces by various dentin surface conditioners. Thirty-two healthy human premolars extracted due to periodontal or orthodontic reasons were used. The teeth were cross-sectioned to expose dentin at the middle portion of the crown with diamond rotary saw. The specimens were then divided into 8 groups. The sectioned dentin surfaces in group 1 to 4 were grinded with No. 400 grit silicone abrasive paper and those in group 5 to 8 were cut with #700 carbide bur under air-water spray. The grinded or cut dentin surfaces were conditioned with 3% $H_2O$, Dentin Conditioner(GC Inter. Corp., Japan), and Scotchprep(3M Dent Prod., U.S.A) according to manufacturer's directions. All the specimens were dried in room temperature for 48 hours, and gold-coated with Eiko ion coater(Eik-engineering Co.), and observed in Hitachi S-450 Scanning electron microscope at 15-25 KV. The following results were obtained; 1. The dentin surfaces grinded with the silicon abrasive paper were rougher in texture and heavier in amount of smear layer than those cut with the carbide bur. 2. Scrubbing of 3% $H_2O_2$ was not effective in removing dentinal smear layer. 3. 20-second conditioning of Dentin Conditioner (GC Inter. Corp) resulted in the removal of a significant amount of the smear layer without removing the tubular plugs and dissolving the peritubular dentin. 4. Scotchprep removed the smear layer very effectively. But at the same time it dissolved the peritubular dentin. 5. Irrespective of the uses of the silicon carbide abrasive paper or the carbide bur the morphological changes of dentin surfaces treated with the same conditioning agents were similar.

• Journal of Periodontal and Implant Science
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• 제37권2호
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• pp.201-208
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• 2007

The purpose of this study was to evaluate the effect of diode laser & desensitizing agents to overcome hypersensitizing root surfaces problem after periodontal treatment. 20 patients(60 teeth) presented were volunteered in this study. Diode laser & MS coat was respectively applied on hypersensitizing root surfaces after periodontal treatments. Following application they were evaluated immediately. The results were as follows: 1. The frequency and degree of root surface hypersensitivity levels were measured by the sequence of tactile and air stream. 2. Reduction of root surfaces hypersensitivity by tactile were for Diode laser and Ms coat application respectively $3.0294{\pm}2.0224$ and $3.2692{\pm}1.6139$. 3. Reduction of root surfaces hypersensitivity by air stream were for Diode laser and Ms coat apapplication respectively $3.0294{\pm}2.0224$ and $2.2692{\pm}1.6139$. 4, It could be said that Diode Laser and Ms coat application were significantly effective in reducing dentin hypersensitivity as far as concerned effect, Ms coat applicatio showed more effective than Diode laser. In conclusion, both methods were significantly effective in reducing dentinal hypersensitivity. Therefore, it was recommended that Diode laser and desensitizing agents could be used routinely for patients dentinal hypersensitivity following periodontal treatment.

• Restorative Dentistry and Endodontics
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• 제48권1호
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• pp.8.1-8.8
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• 2023

Objectives: This study was designed to evaluate the parameters of bonding performance to root dentin, including push-out bond strength and dentinal tubular biomineralization, of a hydraulic bioceramic root-end filling material premixed with dimethyl sulfoxide (Endocem MTA Premixed) in comparison to a conventional powder-liquid-type cement (ProRoot MTA). Materials and Methods: The root canal of a single-rooted premolar was filled with either ProRoot MTA or Endocem MTA Premixed (n = 15). A slice of dentin was obtained from each root. Using the sliced specimen, the push-out bond strength was measured, and the failure pattern was observed under a stereomicroscope. The apical segment was divided into halves; the split surface was observed under a scanning electron microscope, and intratubular biomineralization was examined by observing the precipitates formed in the dentinal tubule. Then, the chemical characteristics of the precipitates were evaluated with energy-dispersive X-ray spectroscopic (EDS) analysis. The data were analyzed using the Student's t-test followed by the Mann-Whitney U test (p < 0.05). Results: No significant difference was found between the 2 tested groups in push-out bond strength, and cohesive failure was the predominant failure type. In both groups, flake-shaped precipitates were observed along dentinal tubules. The EDS analysis indicated that the mass percentage of calcium and phosphorus in the precipitate was similar to that found in hydroxyapatite. Conclusions: Regarding bonding to root dentin, Endocem MTA Premixed may have potential for use as an acceptable root-end filling material.

• Journal of Periodontal and Implant Science
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• 제27권1호
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• pp.191-203
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• 1997

Recently, alteration on chemical treatment on the root and removal of pathologic bacteria, which is the main reason for periodontal disease, by complete removal of infected cementum layer was been emphasied In this study, teeth extracted due to periodontal disease were root planed using periodontal curette and roto bur. Then they were treated with different concentration of Tetracycline HCI at different time. The state of root surface and change in the pre and post treatment was observed. The results were as follows. 1. The group treatment with periodontal curette and saline showed remaining plaque, debris and irregular surface and no dentianl tubule orifice could be seen. 2. The group treatment with periodontal curette and tetracycline HCI showed process compoed with decacified material and there was concanity seemed to be a lacunae of cementocyte. 3. The group treatment with roto bur and saline, there was no remaning plaque and partial dentinal tubule orifice could be seen but smear layer covering them.4. The group treatment with roto bur and tetracycline HCI showed various shape and size dentinal tubule orifice could be seen. From the results, roto bur showed cleaner surfaces than treatment with periodontal curette. But still smear layer existed. Thus for regeneration of periodontal tissue, chemical treatment using tetracycline HCI should follow roto bur treatment. And it is considered that the treatment time is more important than the concentration of tetracycline HCl.

• Restorative Dentistry and Endodontics
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• 제20권2호
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• pp.463-486
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• 1995

The effect of moistening and air-drying of acid-conditioned dentin before priming on the formation of resin-dentin hybrid zone was investigated, Freshly extracted human molars were used and divided at random into 5 groups, Groups 1 - 3 consisted of specimens conditioned with 10 % phosphoric acid for 20 seconds; Group 1 served as a control in which the conditioned dentin was simply blot-dried with a damp facial tissue; Group 2 was air dried for 30 seconds ; Group 3 was air dried for 30 seconds and immediately remoistened for 10 seconds with air-water syringe. and then the specimen was blot-dried with a damp facial tissue. Groups 4-5 were not acid conditioned ; In group 4, the smear layer on the dentin was blot dried before primer placement; Group 5 was air dried only for 30 seconds, The acetone-based primer and bonding agent of All Bond 2 (Bisco. Inc., USA) and composite resin (Z-100, 3M Dental products, USA) were applied for acid conditioned dentin and non-conditioned dentin. The morphologic ultrastructure of resin-dentin hybrid zone was examined by the use of SEM and TEM. and the existence of inorganic material and analysis of Ca/P weight-percent ratio in the resin-dentin hybrid zone were revealed by the EDAX, The results were as follows : 1. In the moistened specimens from acid-conditioned groups, the resin penetrated about 3-$4{\mu}m$ into dentin and the denatured collagen smear layer was not present at the surface. The resin tag was formed to a thickeness of 3-$4{\mu}m$ at the upper part of dentinal tubule and compactively connected to each other by means of many lateral branching. 2. In the air-dried specimens from acid-conditioned groups, the resin penetrated about 2.0-$2.5\;{\mu}m$ into dentin and an upper thin black layer to a thickness of 30-35nm was identified between adhesive resin and demineralized collagen layer. The resin tag to have a diameter of $2.5{\mu}m$ was formed at the upper part of dentinal tubule. However the funnel shape of the tag was not notable compared to the moistened specimens. 3. In the remoistened specimens from acid conditioned groups, the resin penetrated about 2.0-$2.5{\mu}m$ into dentin and an upper black layer was not present. The resin tag at the upper part of dentinal tubule was formed less than $2{\mu}m$ and was weakly connected to each other by means of few lateral branching. 4. In the non-conditioned groups, the smear layer was formed to a thickness of $0.5{\mu}m$ at dentin surface. However, the resin-dentin hybrid zone was not identified by TEM. The evidence of resin penetration into intertubular and intratubular dentin did not show. 5. All the acid-conditioned groups showed that the detected calcium and phosphorus weight percent ratios at the $2{\mu}m$ upper portion from the resin-dentin interface into the resin were much higher than that at the $2{\mu}m$ lower portion from the resin-dentin interface to dentin. (P<0.01).

• Restorative Dentistry and Endodontics
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• 제18권1호
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• pp.73-83
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• 1993

산 처리방법에 따른 상아질 접착을 평가하고 표면처리 후의 상아질 표면의 성상변화 및 파단면의 양상을 관찰하기 위해 발거된 구치 에 10% polyacrylic acid (GC Dental Industrial Corp., U. S. A.), 10 % 인산(Bisco Inc., U. S. A.) 및 10-3 용액 (Parkell Bio-Materials, U. S. A.)을 사용하여 상아질 표면을 처리하고 모든 시편에 상아질 접착제인 All Bond 2$^{(R)}$(Bisco Inc., U.S.A.)를 도포하였으며 복합레진 (Silux Plus$^{(R)}$, 3M Co., U.S.A.)을 첨가한 후 접착강도를 측정하고 상아질 표면 및 파단면을 주사 전자현미경으로 관찰, 비교하여 다음과 같은 결과를 얻었다. 1. 접착강도는 상아질 표면을 산 처리한 군이 무처리한 대조군에 비해 높게 나타났고, 산처리를 시행한 군들 간에는 10-3 용액으로 처리한 군이 가장 높았으며 10% 인산으로 처리한 군, 10% polyacrylic acid로 처리한 군의 순이었다(p<0.01). 2. 상아질 표면의 관찰에서, 무 처리의 상아질 면은 상아세관이 개방되지 않은 채 도말층으로 덮혀 있었고, 10% polyacrylic acid로 처리한 상아질 면은 도말충이 제거되고 상아세관이 개방되어 있었으나 상아세관 내에 smear plug이 일부 남아 있었으며, 10% 인산또는 10-3 용액으로 처리한 상아질 면은 도말층 및 smear plug이 모두 제거되고 상아세관이 완전히 개방되어 있음이 관찰되었다. 3. 파단면의 관찰에서, 무 처리군에서는 도말층 내에서 파단이 일어났으며, 10% polyacrylic acid로 처리한 군에서는 상아세관 내 잔존 레진 tag이 관찰되지 않았으나 10% 인산 및 10-3 용액으로 처리한 군에서는 상아세관 내의 잔존 레진 tag이 관찰되었다. 4. 파단 양상에 있어서, 접착강도가 큰 군일수록 응집성 파단의 빈도가 증가되어 나타났으며, 각 시편에서 구한 접착강도와 응집 파단율의 상관 계수는 0.71이었다.

• Restorative Dentistry and Endodontics
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• 제7권1호
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• pp.65-69
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• 1981

This study was conducted to evaluate the cleansing effect of RC-Prep (10% Urea-peroxide, 15% EDTA) on apical third of root canal. Thirty single rooted human teeth were divided into three groups, and ten canals in each group were all enlarged three sizes greater than their original diameter with K-type files and irrigated with each of three irrigants. The three used irrigants were RC-prep (Premier Co.) in combination with 3.5% Sodium hypochlorite, Normal saline, 3.5% Na OCL. In each group, one of three irrigants were used in conjunction with instrumentation as they would be during clinical condition. After final irrigation, the canals were dried with paper points and the teeth were split longitudinally. The cleanness of canal walls iii the apical region were examined with Scanning Electron Microscope. The following results were drawn. 1. The use of Rc-Prep in combination with 3.5% NaOCl showed more clean canal surface than the use of other two irrigants. 2. The canals used RC-Prep in combination with 3.5% NaOCl revealed remnants of pulp tissue and smeared layer, but the openings of dentinal tubules were relatively clean and wide. 3. There was no significant difference in the debridement effect of 3.5% NaOCl and Saline solution. 4. The use of Saline solution showed great amount of remnants of pulp tissue which couldn't find in the use of 3.5% NaOCl.

• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2001년도 춘계학술대회
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• pp.243-244
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• 2001

Root resorption is conventionally divided into internal and external varieties. Internal resorption occurs where there is loss of the internal wall of the root canal. and is usually associated with a localized area of necrotic pulp(Trope '||'&'||' Chivian 1984). External resorption occurs where there is loss of the external surface of the root and the resorption may be either transient or progressive(Tronstad 1988). External inflammatory resorption usually occurs following damage to the periodontal ligament or where there is communication between the periodontal ligament and a necrotic pulp. via open dentinal tubules or accessory canals. This type of resorption is usually progressive until root canal treatment is instituted (Barclay 1993).

• Journal of Periodontal and Implant Science
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• 제27권3호
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• pp.495-514
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• 1997

The purpose of this study was to evaluate the in vitro effects of Nd:YAG laser irradiation on removal of a root surface smear layer after root planing in comparison with Tetracycline HCl. The 60 extracted human teeth due to severe periodontal disease were vigorously scaled and root planed with Gracey curet. Thirty specimen($5{\times}5{\times}2mm$) were obtained from root planed surface of 30 human teeth and assigned randomly to one of three groups : root planed group(5 specimen), Tetracycline HCI group(5 specimen, burnished for 5 minutes), and Nd:YAG laser group(25 specimen, German Dental Laser, Fotona Twinlight). Nd:YAG laser group was divided into 4 subgroups according to power of 1W, 1.5W, 2W, 3W at frequency to 10Hz. The specimen were then fixed, and examed by Scanning electron microscopic study. 30 of 60 human teeth used to measurement of the intrapulpal temperature rise during laser irradiation. Laser-irradiated surface exhibited various surface texture from relative flat surface to irregular surface with patent dentinal tubules of various shape and size. In some area, the root surface alteration which are carbonization, pit and crater formation and melting and resolidification were observed. The number of exposed dentinal tubules per unit($100_{\mu}m^2$) on tetracycline HCI group was more than that in the laser group below 1.5W of power(150mJ/pulse) and was significantly less than that in laser group above 2W of power(200mJ/pulse)(P<0.OOl). As power increased the intrapulpal temperature rise also increased. The result suggested that the parameter which effectively remove root surface smear layer than tetracycline HCI may cause thermal damage to pulp and root surface alteration result from laser exposure would indicate need for additional instrumentation. Thus, Nd:YAG laser irradiation in these parameter may not be appropriate for clinical use as adjunct to conventional periodontal therapy.