• Restorative Dentistry and Endodontics
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• 제20권1호
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• pp.113-128
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• 1995

The purpose of this study was to investigate the effect of stannous fluoride on the dentin bonding with three kinds of commercially available dentin bonding systems containing different adhesive monomers. Dentin specimens with exposed labial dentin prepared from freshly extracted bovine mandibular anterior teeth were divided into experimental and control groups. The specimens of experimental groups were bonded with dentin bonding systems and composite resins including All bond 2 ㅡ& Bisfil, Scotchbond Multi-Purpose & Z100, and Denthesive II Charisma after 2 % stannous& fluorided application for S minutes and washing for 1 minute. The specimens of control groups were bonded with the same dentin bonding systems and composite resins as used in the experimental groups. After bonded specimens were stored in $37^{\circ}C$ distilled water for 24 hours, the tensile bond strength and cohesive failure rate were measured, and then the pretreated dentin surfaces and the fractured dentin surfaces were examined under scanning electron microscope. The results were as follows : Mean bond strength of stannous fluoride applied groups of All bond 2, Scotchbond MP, and Denthesive II were 2.5MPa, 1.1MPa, and 1.1MPa respectively, and those of control groups were 7.5MPa, 8.1MPa, and 4.6MPa. Bond strength values of stannous fluoride applied groups were significantly lower than those of the control groups(p<0.05). SEM findings of dentin surfaces after stannous fluoride application demonstrated an appearance of partially remained smear layer and smear plugs inspite of pretreatment with 10 % phosphoric aicd or maleic acid solution, and an appearance of smear layer covered surface under Denthesive II priming. But those of control groups commonly showed clean dentin surfaces without smear layer and smear plugs. On SEM observation of the fractured dentin-resin interface, while most of the specimens of stannous fluoride applied groups showed adhesive failure mode, those of All bond 2 and Scotchbond MP control groups showed mainly adhesive-cohesive mixed failure mode, and mainly adhesive failure mode in Denthesive II control group.

• 한국치위생학회지
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• 제10권5호
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• pp.947-953
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• 2010

Objectives : The purpose of this investigation was to evaluate the remineralization and acid resistance in fluoride varnish by Micro-computed tomography (micro CT). Methods : Specimens of bovine teeth enamel were embedded in resin, polished and randomly divided into 3 groups (a control group, a NaF solution group, a fluoride varnish group). Each group has 3 specimens that was standardized according to Vickers hardness number (VHN). Specimens were immersed in demineralization solution for 72 hours. The control group had no treatment, the NaF solution group was treated by a 5% NaF solution for 4 minutes, and the fluoride varnish group was treated by a fluoride varnish for one hour. All specimens were subjected to a chemical pH cycling method for 14 days. After a chemical pH cycling method, the density were measured using micro CT. Then, specimens were immersed in each demineralization solution for 72 hours. After demineralization processed, the density were measured using micro CT. Results : 1. The density was significantly higher in the fluoride varnish and 5% NaF solution group than that of the control group after 14 days cycling (p<0.05). And the density value of the fluoride varnish group was higher than that of the 5% NaF solution, with no significant difference. 2. The differences of density after acid resistance treatment were statistically significant among 3 groups(p<0.05). Conclusions : It is suggested that fluoride varnish showed the remineralizing effect and acid resistance effect on the enamel, and micro CT could be used to evaluate the change of enamel lesion.

• Journal of Periodontal and Implant Science
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• 제36권3호
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• pp.757-765
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• 2006

Human periodontal ligament fibroblasts (hPDLF) are very important for curing the periodontal tissue because they can be differentiated into various cells. A tissue engineering approach using a cell-scaffold is essential for comprehending today's periodontal tissue regeneration procedure. This study examined the possibility of using an acellular dermal matrix as a scaffold for human periodontalligament fibroblast (hPDLF). The hPDLF was isolated from the middle third of the root of periodontally healthy teeth extracted for orthodontic reasons. The cells were cultured in a medium containing Dulbecco's modified Eagle medium supplemented with 10% fetal bovine serum at $37^{\circ}C$ in humidified air with 5% $CO_2$. The acellular dermal matrix(ADM) was provided by the US tissue banks(USA). Second passage cells were used in this study. The hPDLF cells were cultured with the acellular dermal matrix for 2 days, and the dermal matrix cultured by the hPDLF was transferred to a new petri dish and used as the experimental group. The control group was cultured without the acellular dermal matrix, The control and experimental cells were cultured for six weeks. The hPDLF cultured on the acellular dermal matrix was observed by Transmission Electron microscopy (TEM). Electron micrography shows that the hPDLF was proliferated on the acellular dermal matrix. This study suggests that the acellular dermal matrix can be used as a scaffold for hPDLF.

• 대한소아치과학회지
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• 제29권1호
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• pp.30-37
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• 2002

치아 수복 후 나타날 수 있는 술 후 동통과 치수 병변의 주원인은 수복재 자체의 독성보다는 박테리아의 침투에 의한 것으로 알려져 있으며, 와동내 항균제 처리는 잔존 박테리아를 제거하여 제 증상을 완화하는데 효과적이지만, 상아질면이나 상아 세관에 잔유물을 남겨 상아질 결합제와 치질간의 긴밀한 결합을 방해하여, 미세누출을 증가시키고, 결합강도를 약화시킬 수 있다고 알려져 있다. 2% 클로르헥시던 도포가 접착성 수복물과 치질과의 결합강도 및 미세누출에 미치는 영향을 평가하기 위하여, 건전한 소의 전치 상아질을 노출시키고 와동을 형성한 후, 클로르헥시딘을 도포하고 복합레진, 컴포머 그리고 글라스아이오노머를 각 제조사의 지시에 따라 각각 충전하고, 1000회 열순환 처리 후 전단 결합 강도와 미세누출 양상을 비교 평가하였다. 상아질 전단 결합 강도와 수복재 변연 미세누출 양상에서 실험군과 대조군간에 통계학적 유의차를 보이지 않았다.

• Journal of Periodontal and Implant Science
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• 제30권1호
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• pp.167-180
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• 2000

The present study evaluated the effects of guided tissue regeneration using biodegradable membrane, with and without calcium-phosphate thin film coated deproteinated bone powder in beagle dogs. Contralateral fenestration defects(6 × 4 mm) were created 4 mm apical to the buccal alveolar crest on maxillary canine teeth in 5 beagle dogs. Ca-P thin film coated deproteinated bone powder was implanted into one randomly selected fenestration defect(experimental group). Biodegradable membranes were used to provide bilateral GTR. Tissue blocks including defects with overlying membranes and soft tissues were harvested following a four- & eight-week healing interval and prepared for histologic analysis. The results of this study were as follows. 1.......The regeneration of new bone, new periodontal ligament, and new cementum was occurred in experimental group more than control group. 2.......The collapse of biodegradable membranes into defects were showed in control group and the space for regeneration was diminished. In experimental group, the space was maintained without collapse by graft materials. 3........In experimental group, the graft materials were resorbed at 4 weeks after surgery and regeneration of bone surrounding graft materials was occurred at 8 weeks after surgery. 4.......Biodegradable membranes were not resorbed at 4 weeks and partial resorption was occurred at 8 weeks but the framework and the shape of membranes were maintained. No inflammation was showed at resorption. In conclusion, the results of the present study suggest that Ca-P thin film coated deproteinated bone powder has adjunctive effect to GTR in periodontal fenestration defects. Because it has osteoconductive property and prohibit collapse of membrane into defect, can promote regeneration of much new attachment apparatus.

• 대한치과보철학회지
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• 제32권4호
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• pp.593-607
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• 1994

The purpose of this study is to evaluate the effect of the bone morphogenetic protein, bone matrix gelatin and collagen matrix on the amount and shape of generating new bone adjacent to the implant. Implants were inserted in the mandible of adult dogs at 2 months after teeth extraction. Artificial bony defects, 3mm in width and 4mm in depth were made at the mesial and distal side of implant. Experimental groups were divided into three groups ; Group 1 : Defects filled with collagen matrix and bone morphogenetic protein, Group 2 : Defects filled with bone matrix gelatin. Control group : Defects filled with only collagen matrix. After implantation, the animals were sacrificed at 1,3,5 and 10 weeks for light microscopic examination. For the fluorescent microscopic examination. each tertracycline Hcl and calcein were injected at 1, 3, 5, 8 and 10 weeks after implantation. The results obtained were as follows : 1. The molecular weight of bovine BMP was about 18,100 by hydroxyapatite chromatography. 2. Osseointegration was observed in experimental groups 1 & 2, and BMG and BMP had an excellent bone forming capability as a filling materials to the repair of the bone defects. 3. The degree of healing of bone defect area, the experimental group 1 showed more prominent bone formation than control group, and the control group showed fibrous connective tissue between the implant and the bone. 4. In the fluorescent microscopic findings, bone remodelling was observed regenerative lamellar bone at defect area in experimental group 1, and partial remodelling in experimental group 2, In the control group, fibrous connective tissue was observed between the implant and bone surface and sign of remodelling was not apperaed. Above results suggest that BMP has rapid osteoinductive property and can be used clinically as a bone substitute on bone defects around implants.

• Restorative Dentistry and Endodontics
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• 제26권1호
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• pp.41-50
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• 2001

The purpose of this study was to examine the influences of camphoroquinone on the properties of five experimental composites. The contents of camphoroquinone were varied as 0.2%, 0.3%, 0.4%, 0.5%, and 0.6%, with silanized filler 75% and tertiary amine 0.2%. Five kinds of experimental composites were prepared, and diametral tensile strength, shear bond strength, depth of cure and yellowish discoloration were tested as a measurement. Specimen numbers of 10 were applied to all test items and experimental groups. Specimens for testing the diametral tensile strengths with internal diameter of 6mm in diameter and 3mm in height were filled with 5 experimental composites which were crushed with 1mm/min cross-head speed on Instron universal testing machine (Model No. 4467). Shear bond strength was measured on specimens attached to bovine teeth enamel etched with 37% phosphoric acid. Depth of cure was measured by the measurement of height of specimens which were removed the un-polymerized portion with acetone. Yellowness measurements were made by chromometer(Minolta Co. Japan) using L$^*$a$^*$b$^*$ values. ANOVA and Multiple range tests were used analyzed data with confidence level at 95%. The mean value of the shear bond strengths ranged from 31.03MPa to 39.49MPa. Following results were obtained ; 1. Diametral tensile strength was highest in experimental group 3, then was not affected by the contents of camphoroquinone ($r^2$=0.0422). 2. Composite resins containing 0.4% camphoroquinone showed the highest shear bond strength, but there was no statistical significance (p=0.3718). 3. Camphoroquinone reduces the depth of cure in the composite resins (p=0.0004, $r^2$=0.9483). 4. Camphoroquinone made the composites yellowish ($r^2$=0.9815). These results mean that increased content of camphoroquinone reduces the depth of cure, and that camphoroquinone make composites yellowish.

• Restorative Dentistry and Endodontics
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• 제21권2호
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• pp.585-601
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• 1996

The purpose of this study was to elucidate the effect of blood-and saliva-contamination during dentin pretreatment procedure on tensile bond strength, and to investigate the effect of contaminant-removing treatments on the recovery of bond strength of dentin bonding agents. Dentin specimens prepared from freshly extracted bovine mandibular anterior teeth were divided into non-contaminated control and contaminated experimental groups. The specimens of the contaminated group were contaminated with saliva or blood after etching or priming procedure, followed by contaminant-removing treatments. All the specimens were bonded with All Bond$^{(R)}$ 2 dentin bonding agent and Bisfil$^{TM}$ composite resin or Scotchbond$^{TM}$ Multipurpose and Z100. After all the bonded specimens were stored in $37^{\circ}C$ distilled water for 24 hours, tensile bond strengths were measured. The contaminated dentin and fractured dentin surfaces were examined under the scanning electron microscope. The results were as follows : Contaminated specimens showed lower bond strength than non-contaminated ones regardless of the kind of contaminant, contamination time and contaminant-removing treatments, except specimens which were acid-etched following saliva contamination after etching in All Bond$^{(R)}$ 2 groups (p<0.05). Blood contaminant resulted in much bond strength decrease than saliva ones (p<0.01), and contamination after priming resulted in much decrease in bond strength than after etching (p<0.01). Re-etching resulted in increase of bond strength in the specimens contaminated with saliva after etching but not in blood contaminated ones. Re-priming resulted in increase of bond strength in the specimens contaminated after priming regardless of the kind of contaminant.

• 대한치과재료학회지
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• 제44권1호
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• pp.21-31
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• 2017

The purpose of this study was to fabricate a biocompatible fluoride varnish with sustained fluoride release, and to compare it with commercial fluoride varnishes. For the experimental fluoride varnish, bis-GMA (BG) or two types of rosin (KR-610: K0, KR-612: K2) were used as bases. Either ethyl acetate or ethanol was added as solvent and 5 wt% NaF was used. 5 mg of experimental F- varnishes and 2 commercial products, Cavity shield (CS) and Flor-opal (FO), were applied on a labial surface of bovine teeth ($10mm{\times}7mm$). The amount of fluoride release was measured at 1 hr, 2 hrs, 3 hrs, 4 hrs, 8 hrs, 12 hrs, 1 day, 3 days, 5 days, 10 days, 15 days, 20 days and 30 days. MTT test was done with diluted F- varnishes using ethanol. Statistical analysis was done with one-way ANOVA and Duncan multiple range test (${\alpha}=0.05$). BG showed the highest fluoride release at 1 hr (P<0.05), while that of K0 was highest at 2 hrs (P<0.05). From 1 day to 5 days, experimental fluoride varnishes showed higher fluoride release than the commercial products (P<0.05), and there were no significant differences after 5 days (P>0.05). For MTT test, K0 and FO showed higher cell viability than other experimental groups (P<0.05), with no significant differences with K2 (P>0.05). Considering the sustained fluoride release and cell viability of the experimental rosin-based fluoride varnishes compared with commercial products, it will be appropriate for clinical application.

• Journal of Periodontal and Implant Science
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• 제49권2호
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• pp.90-104
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• 2019

Purpose: The aim of this study was to evaluate clinical and radiographic changes and the survival rate after periodontal surgery using deproteinized bovine bone mineral (DBBM) with 10% collagen or DBBM with a collagen membrane in endo-periodontal lesions. Methods: A total of 52 cases (41 patients) with at least 5 years of follow-up were included in this study. After scaling and root planing with or without endodontic treatment, periodontal regenerative procedures with DBBM with 10% collagen alone or DBBM with a collagen membrane were performed, yielding the DBBM + 10% collagen and DBBM + collagen membrane groups, respectively. Changes in clinical parameters including the plaque index, bleeding on probing, probing pocket depth, gingival recession, relative clinical attachment level, mobility, and radiographic bone gains were evaluated immediately before periodontal surgical procedures and at a 12-month follow-up. Results: At the 12-month follow-up after regenerative procedures, improvements in clinical parameters and radiographic bone gains were observed in both treatment groups. The DBBM + 10% collagen group showed greater probing pocket depth reduction ($4.52{\pm}1.06mm$) than the DBBM + collagen membrane group ($4.04{\pm}0.82mm$). However, there were no significant differences between the groups. Additionally, the radiographic bone gain in the DBBM + 10% collagen group ($5.15{\pm}1.54mm$) was comparable to that of the DBBM + collagen membrane group ($5.35{\pm}1.84mm$). The 5-year survival rate of the teeth with endo-periodontal lesions after periodontal regenerative procedures was 92.31%. Conclusions: This study showed that regenerative procedures using DBBM with 10% collagen alone improved the clinical attachment level and radiographic bone level in endo-periodontal lesions. Successful maintenance of the results after regenerative procedures in endo-periodontal lesions can be obtained by repeated oral hygiene education within strict supportive periodontal treatment.