• The Journal of Korean Academy of Prosthodontics
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• v.48 no.1
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• pp.8-15
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• 2010

Purpose: The purpose of this study was to evaluate the effect of various methods of dentin bonding agent application and air abrasion pretreatment on microtensile bond strength between dentin and resin, using a self-etching adhesive system. Material and methods: Thirty freshly extracted human molars were obtained and divided into 6 groups of 5 teeth. A 2-step self etching adhesive system (Clearfil SE Bond) was used for all groups. The control specimens were prepared using a direct immediate bonding technique. The delayed dentin sealing specimens were prepared using an indirect approach without dentin prebonding. The immediate dentin sealing specimens were prepared using dentin prebonding immediately following preparation. Immediate dentin sealing teeth and delayed dentin sealing teeth had provisional restorations using Fermit for two weeks. Then all specimens of each group were divided into two groups of three, depending on air abrasion pretreatment. Composite "crowns" were incrementally built on and specimens were stored in water for 24 hours. All teeth were prepared for a microtensile bond strength test. Bond strength data were analyzed with a one-way ANOVA test, and post hoc comparison was done using the Scheffe's test. Results: The mean microtensile bond strengths of all groups were not statistically different from each other. Conclusion: When preparing teeth for indirect restorations, IDS and DDS with Clearfil SE bond, have no difference on the microtensile bond strength between dentin and resin. Air abrasion pretreatment did not affect the microtensile bond strength when using IDS and DDS with Clearfil SE bond.

• Restorative Dentistry and Endodontics
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• v.35 no.5
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• pp.313-320
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• 2010

Objectives: The aim of this study was to examine changes in the dentinal fluid flow (DFF) during desensitizing agent application and to compare permeability after application among the agents. Materials and Methods: A Class 5 cavity was prepared to exposure cervical dentin on an extracted human premolar which was connected to a sub-nanoliter fluid flow measuring device (NFMD) under 20 cm water pressure. DFF was measured from before application of desensitizing agent (Seal&Protect, SP; SuperSeal, SS; BisBlock, BB; Gluma desensitizer, GL; Bi-Fluoride 12, BF) through application procedure to 5 min after application. Results: DFF rate after each desensitizing agent application was significantly reduced when compared to initial DFF rate before application (p < 0.05). SP showed a greater reduction in DFF rate than GL and BF did (p < 0.05). SS and BB showed a greater reduction in DFF rate than BF did (p < 0.05). Conclusions: Characteristic DFF aspect of each desensitizing agent was shown in NFMD during the application procedure.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.4
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• pp.372-380
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• 2008

Purpose: The purpose of this study was to evaluate the effect of various methods of dentin bonding agent application on microtensile bond strength between dentin and resin, using a 2-step etch-and-rinse dentin bonding agent. Material and methods: Twenty freshly extracted human molars were obtained and divided into 4 groups of 5 teeth. 2-step etch-and-rinse dentin bonding agent was used for all groups. The control specimens were prepared using a direct immediate bonding technique. The delayed dentin sealing (A, C) specimens were prepared using an indirect approach with delayed dentin sealing. For group A, resin was built-up on uncured dentin bonding agent, and for group C, resin was built-up on pre-cured dentin bonding agent. Preparation of the immediate dentin sealing (B) specimens also used an indirect approach with immediate dentin sealing immediately following preparation. All teeth were prepared for a microtensile bond strength test. Specimens were stored in water for 24 hours. Ten beams (1.0 ${\times}$ 1.0 ${\times}$ 11 mm) from each tooth were selected for testing. Bond strength data (MPa) were analyzed with a one-way ANOVA test, and post hoc comparison was done using the Scheffe's test. Results: The mean microtensile bond strengths of control group, B and C (DDS with pre-cure) were not statisticaaly different from each other at 32.7, 33.3, 34.2 MPa. the bond strength for group A (DDS without pre-cure), 19.5 MPa, was statistically different (P < .01) from the other 3 groups. Conclusion: When preparing teeth for indirect bonded restorations, DDS with pre-curing dentin bonding agent and IDS results in the same bond strength between dentin and resin. On the contrast, the bond strength was decreased when DDS without pre-curing dentin bonding agent was used.

• Journal of Periodontal and Implant Science
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• v.32 no.2
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• pp.371-378
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• 2002

In this study, 40 hypersensitive teeth of 19 patients were investigated. The procedures performed were as follows: Before desensitization, EPT at occlusal third of buccal surface was done for the evaluation of pulp vitality and the EPT value was recorded for the reference value. And mechanical and thermal test was executed for the test of hypersensitivity. If the tooth responded to the above tests, we did EPT at the exposed surface, using toothpaste as a electrolite medium and recorded the EPT value at patient's response. After the tests had been done, desensitization procedures with Gluma(R) Desensitizer were performed according to the manufacturer's instructions. After desensitization, the same tests except EPT at occlusal third were repeated. All the 40 teeth responded positive before desensitization and negative after desensitization procedures. The EPT value at occlusal third ranged from 31 to 65 (48.9${\pm}$7.2). Before desensitization 34 teeth responded at EPT value of 2 and the remaining 6 teeth was in the range of 17 to 25. After desensitization all 40 teeth responded from 12 to 27 (19.6${\pm}$3.5). The 6 teeth responded at greater number than 2 before desensitization was in the range of 18 to 23. Within the limitations of this study we can conclude that: When a tooth with dentinal hypersensitivity responds to mechanical and thermal stimulation, the tooth shows very low resistance to electricity at the exposed surface while when a tooth is desensitized and doesn't show respond to mechanical and thermal stimuli, the tooth shows increased level of resistance to electric stimulation at the exposed surface. EPT can be used for the diagnosis of dentinal hypersensitivity. Furthermore EPT will be useful to evaluate the outcome of desensitization procedures. However, EPT is not a valid tool for measuring dentinal hypersensitivity.

• Restorative Dentistry and Endodontics
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• v.33 no.1
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• pp.9-19
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• 2008

The purpose of this study was: (1) to compare nanoleakage patterns of a conventional 3-step etch and rinse adhesive system and two experimental hydrophobic adhesive systems and (2) to investigate the change of the nanoleakage patterns after load cycling. Two kinds of hydrophobic experimental adhesives, ethanol containing adhesive (EA) and methanol containing adhesive (MA), were prepared. Thirty extracted human molars were embedded in resin blocks and occlusal thirds of the crowns were removed. The polished dentin surfaces were etched with a 35 % phosphoric acid etching gel and rinsed with water. Scotchbond Multi-Purpose (MP), EA and MA were used for bonding procedure. Z-250 composite resin was built-up on the adhesive-treated surfaces. Five teeth of each dentin adhesive group were subjected to mechanical load cycling. The teeth were sectioned into 2 mm thick slabs and then stained with 50 % ammoniacal silver nitrate. Ten specimens for each group were examined under scanning electron microscope in backscattering electron mode. All photographs were analyzed using image analysis software. Three regions of each specimen were used for evaluation of the silver uptake within the hybrid layer. The area of silver deposition was calculated and expressed in gray value. Data were statistically analyzed by two-way ANOVA and post-hoc testing of multiple comparisons was done with the Scheffe's test. Silver particles were observed in all the groups. However, silver particles were more sparsely distributed in the EA group and the MA group than in the MP group (p < .0001). There were no changes in nanoleakage patterns after load cycling.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.4
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• pp.553-565
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• 2001

One-bottle adhesive system was recently developed in order to simplify the clinical skills and save chair time after continuous improvements on dentin bonding agents. To test the shear bond strength of a new "one-bottle adhesive" system to bovine dentin various commercially available one-bottle adhesives(Prime & Bond $2.1^{(R)}$, One Coat $Bond^{(R)}$, Syntac $Sprint^{(R)}$, Single $Bond^{(R)}$) were included for comparison. And we observe the interfacial morphology by scanning electron microscope. The results were as follows; 1. Group II (One Coat $Bond^{(R)}$) showed higher shear bond strength than group I (Prime & Bond $2.1^{(R)}$), group III(Syntac $Sprint^{(R)}$), and group IV(Single $Bond^{(R)}$), but no statistically significant difference was founded between groups(p>.05). 2. Relating reverse-cone shape resin tags were observed in samples of all groups under SEM. We could observed hybrid layer, resin tag and many lateral branches in every group. But, we observed in group III rare lateral branched than other three groups, and discontinuous hybrid layer.

• Restorative Dentistry and Endodontics
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• v.30 no.5
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• pp.402-408
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• 2005

The purpose of this study was to investigate the effects of estrogen deficiency on pulpodentinal complex of tooth in ovariectomized rats. Thirty female Sprague-Dawley rats, 10 weeks old, were used. Rats were grouped into two groups. One group (n = 15) was subjected to sham surgery (SHAM) and the other group (n = 15) was ovariectomized bilaterally (OVX). Animals were sacrificed 12 weeks later, and their mandibular molars and associated periodontal supporting tissues were dissected out, and fixed in $10\%$ buffered formalin. For comparison of groups, immunostained for osteonectin. Histomorphometrical measurement of change of teeth was performed using an image analysis system and paired t-test was used and the level of significance for overall differences was set at p < 0.05. In immunostaining of osteonectin, they were significantly different from each other. The predentin thickness in OVX rats was wider than in SHAM rats. And in SHAM rats, osteonectin was more specifically stained in predentin areas than in OVX rats. These results indicate that estrogen deficiency increased the unmineralized predentin areas and decreased osteonectin content in pulpal tissues in rats. If our result is applicable to human studies, odotoblast is affected by estrogen deficiency.

• Restorative Dentistry and Endodontics
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• v.36 no.6
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• pp.490-497
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• 2011

Objectives: This study examined the effect of the uncured dentin adhesives on the bond interface between the resin inlay and dentin. Materials and Methods: Dentin surface was exposed in 24 extracted human molars and the teeth were assigned to indirect and direct resin restoration group. For indirect resin groups, exposed dentin surfaces were temporized with provisional resin. The provisional restoration was removed after 1 wk and the teeth were divided further into 4 groups which used dentin adhesives (OptiBond FL, Kerr; One-Step, Bisco) with or without light-curing, respectively (Group OB-C, OB-NC, OS-C and OS-NC). Pre-fabricated resin blocks were cemented on the entire surfaces with resin cement. For the direct resin restoration groups, the dentin surfaces were treated with dentin adhesives (Group OB-D and OS-D), followed by restoring composite resin. After 24 hr, the teeth were assigned to microtensile bond strength (${\mu}TBS$) and confocal laser scanning microscopy (CLSM), respectively. Results: The indirect resin restoration groups showed a lower ${\mu}TBS$ than the direct resin restoration groups. The ${\mu}TBS$ values of the light cured dentin adhesive groups were higher than those of the uncured dentin adhesive groups (p < 0.05). CLSM analysis of the light cured dentin adhesive groups revealed definite and homogenous hybrid layers. However, the uncured dentin adhesive groups showed uncertain or even no hybrid layer. Conclusions: Light-curing of the dentin adhesive prior to the application of the cementing material in luting a resin inlay to dentin resulted in definite, homogenous hybrid layer formation, which may improve the bond strength.

• Journal of Oral Medicine and Pain
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• v.23 no.1
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• pp.11-20
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• 1998

저자는 치과용 레이저를 이용한 상아질지각과민증 치료효과를 임상적으로 평가하고자 상아질지각과민증환자 24명을 대상으로 각 환자마다 상아질 지각과민 치아 중 레이저로 치료 할 치아1개(실험군)와 치료하지 않을 치아 1개(대조군)를 선정하여, 치과용 air-syringe에 의한 냉자극과 치과용 탐침자에 의한 기계적 자극을 가한 후 Visual Analogue Scale(VAS)을 통해 지각과민증 정도를 평가하였으며, 이후 실험군 치아의 치경부 마모면에 광섬유 레이저에너지 전달방식의 펄스형 Nd:YAG 레이저의 일종인 Sunlase Master(Sunrise Technologies Inc., U.S.A., 파장 1064nm, 펄스지속시간 120(sec, 광섬유직경 320(m)를 사용하여, 0.3-1.0W, 10Hz 조건으로 환자의 반응에 따라 1회2분을 초과하지 않는 범위 내에서 비접촉식과 접촉식을 병행하여 3회에 걸쳐(초진 당일, 1일후, 3일후) 레이저를 조사한 후 처음조사 직후, 그리고 초진 1일후, 3일후, 7일후, 14일후 VAS를 채득하여 조사전과 비교, 분석, 평가하였던 바, 상아질 지각과민증이 각각 약 50%, 약36%, 약45%, 약 53% 감소하였으나 (p(0.05) 경시적으로는 유의한 차이를 보이지 않았다. 그리고 24명중 9명에 대해서는 초진 30일 후 까지 레이저조사치료효과를 평가하였던 바, 상아질지각과민증이 처음조사 직후, 감소하였으며 (p(0.05)역시 경시적으로는 유의한 차이를 보이지 않았다. 초진 30일 후 상아질지각과민증이 초진 14일 후에 비해 약간 증가되는 경향을 보여, 레이저조사 치료효과가 약화되는 경향인지 여부에 대해 향후 추가적인 연구가 필요할 것으로 사료된다.안되었다.기란 현실적으로 불가능하므로, 본 연구에서는 이러한 제약점을 극복할 수 있는 근사적인 지체시간을 계산하는 방법을 제시한 점에서 의미를 갖을 수 있다.수들은 직업의 선택이나 소득을 예측하기 위한 요소들로 포함될 수 없었다. 따라서 후속연구에서는 이를 보완해야 할 것이며, 최근 들어 우리 나라에서도 재택근무에 대한 관심이 대두되고 있으나 아직 개념정의나 그 중요성과 가치, 그리고 실태 파악과 같은 연구가 활발히 이루어지지 못하고 있으므로 이에 대한 심층적인 연구가 행해져야 할 것이다.d similar flower proceeding dates in all branches. but "Daepung" showed similar flower proceeding dates in all branches.est in HB. Mean period of wetting duration was in the order of DS＞HB＞MB, while the dew point depression was greatest in DS.ANCOVA, Pearson correlation을 이용하여 분석하였으며, 그 결과는 다음과 같다. 캠프 프로그램은 소아 당뇨병 환자의 자기 효능을 증진시키고 환자 역할 행위 이행을 높여주는데 효과적 이었다. 소아 당뇨병 환자의 자기 효능은 환자 역할 행위 이행과 순 상관 관계가 있어, 자기 효능이 증진될수록 환자 역할 행위 이행 정도가 높아졌다. 무조건 사주지 않는다(8.0%), 무조건 사준다(3.1%)로 식품광고에 나오는 식품 요구시 부모의 70.3%가 거절하는 것으로 나타났다. 거절 이유는 건강에 나쁘다는 것이 가장 큰 이유였으며 강남과 강북 어린이간에 유의적인 차이가 있었다(p＜0.001).

• Journal of dental hygiene science
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• v.15 no.3
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• pp.295-300
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• 2015

Odontoclasts and osteoclasts resorb tooth root and alveolar bone, respectively. Many studies have focused on osteoclast formation in periodontitis, but effect of periodontitis on odontoclast formation is not clearly clarified. In this study, we observed formation of odontoclasts as well as osteoclasts in rats with ligature-induced periodontitis. To induce periodontitis, ligatures were placed around the first molars in left mandibles of rats. Rats were sacrificed at days 1, 3, and 10 after ligation. After tartrate resistant acid phosphatase (TRAP) staining in mandible section, the number of TRAP-positive odontoclasts and osteoclasts were histologically counted along the root and the alveolar bone surfaces of tooth, respectively. Odontoclasts increased until day 10 in mesial and furcation root surface, but did not increase in distal root surface. When compared odontoclast formation to osteoclast formation in mesial surface, osteoclasts peaked at day 3, and then decreased gradually, whereas odontoclasts were continuously increased until day 10. The number of odontoclasts was lower than that of osteoclasts before and after periodontitis induction. These indicate that periodontitis increased formation of odontoclasts as well as osteoclasts, but odontoclast formation occurs slower and weaker than that of osteoclasts.