Dissolution behavior and early bone apposition of calcium phosphate-coated machined implants

황지완,이은웅,이중석,정의원,이인섭,최성호 대한치주과학회 2013 Journal of Periodontal & Implant Science Vol.43 No.6

Purpose: Calcium phosphate (CaP)-coated implants promote osseointegration and survival rate. The aim of this study was to(1) analyze the dissolution behavior of the residual CaP particles of removed implants and (2) evaluate bone apposition of CaPcoatedmachined surface implants at the early healing phase. Methods: Mandibular premolars were extracted from five dogs. After eight weeks, the implants were placed according to drillingprotocols: a nonmobile implant (NI) group and rotational implant (RI) group. For CaP dissolution behavior analysis, 8 implantswere removed after 0, 1, 2, and 4 weeks. The surface morphology and deposition of the coatings were observed. For boneapposition analysis, block sections were obtained after 1-, 2-, and 4-week healing periods and the specimens were analyzed. Results: Calcium and phosphorus were detected in the implants that were removed immediately after insertion, and the otherimplants were composed mainly of titanium. There were no notable differences between the NI and RI groups in terms ofthe healing process. The bone-to-implant contact and bone density in the RI group showed a remarkable increase after 2 weeksof healing. Conclusions: It can be speculated that the CaP coating dissolves early in the healing phase and chemically induces early boneformation regardless of the primary stability.

신속 구강 점막 도말 HIV 항체 검사에 대한 일반인/의료진의 사용 후 반응도 연구

황지완(Ji-Wan Hwang),박정철(Jung-Chul Park),최성호(Seong-Ho Choi),김선종(Sun-Jong Kim),강희정(Hee-Jung Kang),이종호(Jong-Ho Lee),신승철(Seung-Chul Shin),차영주(Young-Joo Cha) 대한치과의사협회 2011 대한치과의사협회지 Vol.49 No.1

The aim of this study is to evaluate the patient’s and clinician’s response to rapid oral HIV screening test. Attitude assessment survey was carried out on patients test with rapid oral HIV screening test and clinicians who conducted the test. The patients and clinicians were present at the dental hospital and clinics which were participating in the research project, between March and May 2010. Rapid oral HIV screening test is safe and efficient to the patients. It also demonstrated reliability to accuracy and confidentiality, and high recommendation to rapid oral HIV screening test. The clinician survey revealed high test convenience and high appraisal to patient satisfaction. In conclusion, if rapid oral HIV screening test becomes more common, patients will receive safe and convenient and high reliable HIV infection test, while clinicians will be able to create safe dental care environment.

Development of the implant surgical technique and assessment rating system

박정철,황지완,이중석,정의원,최성호,조규성,채중규,김창성 대한치주과학회 2012 Journal of Periodontal & Implant Science Vol.42 No.1

Purpose: There has been no attempt to establish an objective implant surgical evaluation protocol to assess residents’ surgical competence and improve their surgical outcomes. The present study presents a newly developed assessment and rating system and simulation model that can assist the teaching staffs to evaluate the surgical events and surgical skills of residents objectively. Methods: Articles published in peer-reviewed English journals were selected using several scientific databases and subsequently reviewed regarding surgical competence and assessment tools. Particularly, medical journals reporting rating and evaluation protocols for various types of medical surgeries were thoroughly analyzed. Based on these studies, an implant surgical technique assessment and rating system (iSTAR) has been developed. Also, a specialized dental typodont was developed for the valid and reliable assessment of surgery. Results: The iSTAR consists of two parts including surgical information and task-specific checklists. Specialized simulation model was subsequently produced and can be used in combination with iSTAR. Conclusions: The assessment and rating system provided may serve as a reference guide for teaching staffs to evaluate the residents’ implant surgical techniques.

Surface characteristics of a novel hydroxyapatite-coated dental implant

정의원,황지완,최다예,허경석,권미경,최성호,김희진 대한치주과학회 2012 Journal of Periodontal & Implant Science Vol.42 No.2

Purpose: This study evaluated the surface characteristics and bond strength produced using a novel technique for coating hydroxyapatite (HA) onto titanium implants. Methods: HA was coated on the titanium implant surface using a super-high-speed (SHS) blasting method with highly purified HA. The coating was performed at a low temperature, unlike conventional HA coating methods. Coating thickness was measured. The novel HA-coated disc was fabricated. X-ray diffraction analysis was performed directly on the disc to evaluate crystallinity. Four novel HA-coated discs and four resorbable blast medium (RBM) discs were prepared. Their surface roughnesses and areas were measured. Five puretitanium, RBM-treated, and novel HA-coated discs were prepared. Contact angle was measured. Two-way analysis of variance and the post-hoc Scheffe’s test were used to analyze differences between the groups, with those with a probability of P<0.05 considered to be statistically significant. To evaluate exfoliation of the coating layer, 7 sites on the mandibles from 7 mongrel dogs were used. Other sites were used for another research project. In total,seven novel HA-coated implants were placed 2 months after extraction of premolars according to the manufacturer’s instructions. The dogs were sacrificed 8 weeks after implant surgery. Implants were removed using a ratchet driver. The surface of the retrieved implants was evaluated microscopically. Results: A uniform HA coating layer was formed on the titanium implants with no deformation of the RBM titanium surface microtexture when an SHS blasting method was used. Conclusions: These HA-coated implants exhibited increased roughness, crystallinity, and wettability when compared with RBM implants.

토끼 두개골 결손부에서 가교화된 제 1형 콜라겐 차폐막의 초기 골형성 효과

이은웅,양혜주,황지완,Otgonbayar Unursaikhan,정은주,이중석,정의원,김창성,조규성,최성호 한국생체재료학회 2012 생체재료학회지 Vol.16 No.3

The aim of this study was to evaluate early healing processes in guided bone regeneration using a cross-linked type-I collagen membrane of 1-ethyl-3-(3- dimethyl aminopropyl) carbodiimide (EDC) at rabbit calvarial defects. Eight male New Zealand rabbits were used and four circular calvarial defects were created. Each of the four defects was filled with different graft materials: 1) collagen membrane, 2) biphasic calcium phosphate, 3) collagen membrane with biphasic calcium phosphate, and 4) nothing as control. The animals were sacrificed following two and four weeks of healing periods. Between two healing periods, collagen membrane was resorbed 28.5% and maintained its original shape and marginal integrity. The collagen membrane group resulted in significantly better defect closure compared to control group (p < 0.05). The augmented area was significantly higher in bone graft material applied groups (p < 0.05). There was no statistical difference in new bone formation between all groups at all healing periods, but vascularization was seemed to be promoted and more new bone formation was observed in superficial layer in collagen membrane applied groups. Within the limits of this study, the cross linked collagen membrane maintained its structural integrity and promoted bone regeneration especially in superficial layer.

Role of collagen membrane in lateral onlay grafting with bovine hydroxyapatite incorporated with collagen matrix in dogs

정의원,이중석,이근,이인경,황지완,김민수,최성호,채중규 대한치주과학회 2013 Journal of Periodontal & Implant Science Vol.43 No.2

Purpose: The objective of this study was to elucidate the role of collagen membranes (CMs) when used in conjunction with bovine hydroxyapatite particles incorporated with collagen matrix (BHC) for lateral onlay grafts in dogs. Methods: The first, second, and third premolars in the right maxilla of mongrel dogs (n=5) were extracted. After 2 months of healing, two BHC blocks (4 mm×4 mm×5 mm) were placed on the buccal ridge, one with and one without the coverage by a CM. The animals were sacrificed after 8 weeks for histometric analysis. Results: The collagen network of the membranes remained and served as a barrier. The quantity and quality of bone regeneration were all significantly greater in the membrane group than in the no-membrane group (P<0.05). Conclusions: The use of barrier membranes in lateral onlay grafts leads to superior new bone formation and bone quality compared with bone graft alone.

Periodontal regenerative effect of a bovine hydroxyapatite/collagen block in one-wall intrabony defects in dogs: a histometric analysis

정의원,최성호,이정석,박원영,차재국,황지완,박정철,김창성,조규성,채중규 대한치주과학회 2011 Journal of Periodontal & Implant Science Vol.41 No.6

Purpose: The aim of this study was to elucidate the effect of a bovine hydroxyapatite/collagen (BHC) block in one-wall intrabony periodontal defects in dogs. Methods: A one-wall intrabony periodontal defect (4 mm wide and 5 mm deep) was prepared bilaterally at the mesial side of the mandibular fourth premolar in five beagle dogs. After thorough root planing, block-type BHC (4×5×5 mm) was placed on one side. The contralateral defect area did not receive any material as a sham-surgery control. Histological analysis of the sites was performed after an 8-week healing period. Results: Two of five samples in the experimental group healed well without dissipation of the graft materials, and histological analysis revealed excellent regeneration of the periodontal tissues. However, most of the grafted materials had been displaced in the other three samples, leaving only a small portion of the graft. The measured parameters exhibited large standard deviations,and the mean values did not differ significantly between the experimental and sham-surgery control sides. Conclusions: The application of BHC alone-without a barrier membrane-to wide, one-wall intrabony periodontal defects yielded inconsistent results regarding both periodontal regeneration and substantivity of the graft materials. Thus, the use of a barrier membrane for noncontained-type defects is recommended to improve the stability of the grafted material, and to condense it.

흡연 환자에서의 치주치료와 임플란트 수술

박정철(Jung-Chul Park),정의원(Ui-Won Jung),조규성(Kyoo-Sung Cho),황지완(Ji-Wan Hwang),최성호(Seong-Ho Choi),김창성(Chang-Sung Kim) 대한치과의사협회 2011 대한치과의사협회지 Vol.49 No.10

Cigarette smoking is a significant risk factor for periodontaldiseases and implant treatments. Smoking control is regarded as a key to the success of dental treatments as well as the well-being of the patients. The aim of this study was to reviewthe effects of smoking on periodontal health, and the results of periodontal therapy and implant treatments. Also, in vitro, microbiological, immunological and epidemiological relationships were studied. In vitro studies show that smoking interferes with normal healing process and increased tissue destruction. There is still controversy on the population of microbes of smokers. Smokers showed significantly less gingival inflammation and bleeding on probing compared with non-smokers. After periodontal treatments, a compromised clinical outcome was noted for smokers in terms of pocket depth reduction and gain in attachment levels. In conclusion, data from in vitro, epidemiological, cross-sectional and case?control studiesstrongly suggest that quitting smoking is beneficial to patients before periodontal and implant treatments.