• 대한소아치과학회지
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• 제39권2호
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• pp.145-152
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• 2012

소아치과 임상의는 유구치의 수복 치료에 있어 기성 금속관을 사용할 때, 실제 치아의 크기와 형태가 유사한 기성 금속관을 사용하는 것이 중요하다. 유치 치관의 크기와 형태는 인종에 따라 많은 차이를 보이며, 현재 많이 사용되고 있는 기성금속관은 외국 아동의 기준에 맞춰 제작된 제품으로 한국 아동의 유구치에 적용 시 실제 치아와 차이가 있을 것으로 생각된다. 하지만 최근에는 국산 제품의 기성금속관이 개발되었으며, 이는 한국 아동 유치의 형태학적 특징을 반영하였을 것으로 기대되고 있다. 본 연구에서는 부산, 경남 지역 아동 263명의 상, 하 제 1, 2 유구치 각각의 근원심경, 협설경을 측정한 자료를 바탕으로 한국 아동의 유구치 치관 크기에 대한 계측치를 현재 사용되고 있는 3종의 기성금속관(3M ESPE Stainless Steel Primary Molar Crown, Kids Crown, Sankin Anatom Primary Crown)과 회귀분석을 통해 비교 연구하여 다음과 같은 결과를 얻었다. 1. 세가지 기성금속관 모두에서 근원심경에 대한 협설경의 비율이 실제 치아보다 더 컸다. 2. 근원심경에 대한 협설경의 비율에 있어 3M ESPE Stainless Steel Primary Molar Crown과 Kids Crown은 대체로 비슷했으며, Sankin Anatom Primary Crown은 앞의 두 기성금속관과 차이가 났다. 그리고 이러한 차이는 하악 유구치에서 더욱 두드러졌다. 3. 실제 치아의 근원심경이 평균값과 가까울수록 기성금속관과의 적합도는 더 높으며, 반대로 평균값에서 멀어질수록 적합도는 낮아진다. 4. 실제 치아와 기성금속관 간에 가장 차이가 많이 나는 치아는 하악 제1유구치, 상악 제1유구치이다.

• The Journal of Advanced Prosthodontics
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• 제12권3호
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• pp.173-180
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• 2020

PURPOSE. This study compared digital (reference point matching) and replica methods for measuring marginal and internal fit of full coverage restorations. MATERIALS AND METHODS. A maxillary left first molar typodent was fixed on to an aluminum base and prepared to receive all-ceramic full coverage restoration. The model was scanned with an intraoral scanner (CEREC Omnicam, Sirona, York, PA, USA). Twelve crowns were fabricated from lithium disilicate blocks (IPS emax CAD, Ivoclar Vivadent) and then crystalized. Marginal and internal fit of each restoration was measured by two examiners using replica and a new digital three-dimensional technique. Reliability between the two methods and two examiners was assessed by correlation and Cronbach's Alpha coefficient (P<.05). A Bland-Altman assessment for agreement was used to compare the two methods. RESULTS. Bland-Altman assessment showed that the mean of difference for marginal, absolute marginal, and axial gap was respectively -1.04 ㎛, -41.9 ㎛, and -29.53 ㎛ with limit of agreement (LOA) between -37.26 to 35.18 ㎛ for marginal, -105.85 to 22.05 ㎛ for absolute marginal and -80.52 to 22.02 ㎛ for axial gap. Positive correlation for repeatability (P<.05) in determining marginal and internal gaps by the two examiners in both techniques was revealed. Reliability of both techniques in all sites of measurements was at least good (0.8 ≤ α < 0.9). CONCLUSION. Both measuring techniques appeared highly reliable for evaluating fit of fixed dental restorations, while reference point matching provided higher values in axial and absolute marginal gap assessment.

• 구강회복응용과학지
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• 제33권4호
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• pp.299-306
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• 2017

본 증례는 완전한 디지털 workflow로 단일 치아 임플란트 지지형 보철물을 즉시 부하하여 수복한 증례이다. 하악 제1대 구치 상실로 내원한 환자로, 구강 스캐너로 구내 디지털 인상채득 후, CT데이터와 디지털 스캔 데이터를 통해 제작한 수술용 가이드를 이용하여 임플란트를 식립하였다. 술 후 1주일 후, 맞춤형 지대주와 임시치아를 체결하여 즉시부하 하였다. 술 후 8주 후 지대주 레벨에서 구강스캐너를 이용하여 디지털 인상채득 후, 술 후 3개월에 지르코니아 최종 보철물을 장착하였다. 본 증례는 환자의 만족도 및 정확성 면에서 만족할 만한 결과를 나타내었으며, 완전한 디지털 과정을 통한 수복 결과 정확성, 심미성, 기능성 면에서 만족할 만한 결과를 나타내었기에 보고하는 바이다.

• 대한치과기공학회지
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• 제41권4호
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• pp.271-278
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• 2019

Purpose: To quantify the effect of the crystallization process on lithium disilicate ceramic crowns that are fabricated using a computer-aided design/computer-aided manufacturing(CAD/CAM) system, and to determine whether they are clinically acceptable by comparing values before and after the crystallization process. Methods: The maxillary first molar was selected as the abutment for the experiments. Ten working models were prepared. Marginal and internal gap of 4 groups of lithium disilicate crowns(n=10) fabricated with conventional method. Comparison was performed using the silicone replica technique and 3D superimposition analysis. The marginal and internal gaps of the restoration were measured before and after the crystallization process of this prosthesis. The average value of each part(the average of values measured before and after the crystallization) was statistically analyzed using paired t-test(α=0.05). Results: The results from the second phase of this research, which compared the average value of the gap between the marginal and internal fits of the lithium disilicate single crown before and after the crystallization process, indicated that the marginal gap was larger and the internal gap was smaller after the crystallization process, and this difference was statistically significant (P<0.05) in all the parts evaluated. Conclusion: While the shrinkage that occurs during crystallization does affect the marginal and internal fit of the prosthesis, it cannot be concluded to be a major effect because the resultant distortion was within the clinically acceptable range.

• Journal of Oral Medicine and Pain
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• 제24권1호
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• pp.81-94
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• 1999

This study intends to find usefulness of the computer assisted dental identification in mass disaster. The variety of dental characteristics was investigated through the research of dental records of 508 adults. And a computer assisted simulation program was used to evaluate the selectivity of dental identification. Findings were as follows : 1. Combinations of dental characteristics were found 155 types. The most various dental characteristic was showed on the mandibular first molar. 99.0% of subjects had dental characteristics for dental identification. 2. The posterior teeth, in comparison with anterior teeth, showed higher selectivity in dental identification which was enhanced by information on the material, type and cavity of the restoration. 3. The variety of dental characteristics was mainly found on the combinations of missing tooth with the material, type and cavity of the restoration. 4. The computer assisted dental identification program, with informa- tion about one's tooth state, made individual identification possible when there was only a part of the teeth in a corpse. 5. The computer assisted dental identification had considerably high selectivity based on the variety of dental characteristics. And it was also performed faster and preciser than the existing identification methods. Based on the results of this study, there are various combinations of the feature of the tooth itself with dental characteristics caused by a certain type of treatment on the teeth. And using the computer assisted dental identification program based on this, dental identification can be more efficient economically and more useful than any other forensic identification methods.

• Restorative Dentistry and Endodontics
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• 제25권3호
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• pp.313-320
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• 2000

The purpose of this study was to evaluate on the interfacial morphology between dentin and restorative materials. In this in vitro study, the cavity wall restorated with 3 different kinds of tooth colored restorative materials [resin-modified Glass Ionomer cement (Fuji II LC), composite resin (Z-100), compomer (Dyract)]. The thirty extracted human molar teeth without caries and/or restorations are used. The experimental teeth were randomly divided into three groups of ten teeth each. In each group, Wedge shaped cavities (width: 3mm, length: 2mm, depth: 1.5mm) were prepared at the cementoenamel junction on buccal and lingual surfaces. The adhesive of composite resin were mixed with rhodamine B. Primer of composite resin, Prime & Bond 2.1 of Dyract and liquid of Fuji II LC were mixed with fluorescein. In group 1, the cavity wall was treatment with dentin conditioner, and then restorated with Fuji II LC. In group 2, the cavity wall was treatment with Prime & Bond 2.1 and then restorated with Dyract. In group 3, the cavity wall was etching with 10% maleic acid, applied with primer and bonding agent and then restorated with Z-100. The interface between dentin and restorative materials was observed by fluoresence imaging with a confocal laser scanning microscope. The results were as follows : 1. In Glass ionomer group, adaptation of resin modified Glass-ionomer restoration against cavity wall is tight, but the crack formed inside of restoration were observed. 2. In Dyract group, the penetration of resin tag is shorter and the width of hybrid layer is narrower than composite resin group. 3. In Z-100 group, primer penetrated deeply through dentinal tubule. Also bonding agent was penetrated along the primer, but the penetration length is shorter than primer part, and in 3-D image, the resin tag is conical shape and lateral branch is observed.

• Composites Research
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• 제23권6호
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• pp.39-46
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• 2010

치아의 와동에 수복된 치과용 복합레진을 광(LED) 조사를 통해 정화 수축시키면서 음향방출(acoustic emission, AE) 신호를 검출하였다. 비모수 통계법인 Mann-Whitney법과 Kruskal-Wallis법을 이용하여 시편의 재질과 계면의 접착조건에 따른 AE hit event 수와 최대진폭을 비교 평가하였다. PMMA와 치아시편으로부터 검출된 선호의 최대진폭은 정착조건에 따른 차이가 없었지만 스테인리스 시편으로부터 검출된 신호는 접착조건에 따라 최대 진폭의 차이가 있었다(p<0.05). AE hit event 수는 양호한 접착조건에서 시편의 재질에 따라 차이가 있었고(p<0.05), 세가지 재질의 시편 모두 접착조건이 양호한 실험에서 AE 신호가 적게 검출되었다. SEM을 이용하여 계면에 생성된 캡을 측정한 결과 AE가 많이 검출되고 검출된 신호의 최대 진폭이 큰 시편에서 갱의 폭이 넓고 형성 비율이 높았다.

• The Journal of Advanced Prosthodontics
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• 제12권6호
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• pp.344-350
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• 2020

PURPOSE. Recently introduced hybrid and reinforced glass ceramic computer-aided design/computer-aided manufacturing (CAD/CAM) materials have been used for full-coverage restorations. However; the effect of adjustment and type of materials on internal and marginal adaptation are unknown. This study aimed to evaluate and compare the marginal and internal adaptations of crowns made of three different CAD/CAM materials before and after adjustment. MATERIALS AND METHODS. One acrylic resin maxillary first molar was prepared and served as the master die. Thirty-six restorations were fabricated using CAD/CAM system (CEREC Omnicam, MCXL) with three materials including lithium disilicate (IPS e.max CAD), zirconia-reinforced lithium silicate (Suprinity), and hybrid ceramic (Enamic). Internal and marginal adaptations were evaluated with the reference point matching technique before and after adjustment. The data were analyzed using mixed ANOVA considering α=.05 as the significance level. RESULTS. The effect of adjustment and its interaction with the restoration material were significant for marginal, absolute marginal, and occlusal discrepancies (P<.05). Before adjustment, Suprinity had lower marginal discrepancies than IPS e.max CAD (P=.18) and Enamic (P=.021); though no significant differences existed after adjustment. CONCLUSION. Within the limitations of this study, crowns fabricated from IPS e.max CAD and Suprinity resulted in slightly better adaptation compared with Enamic crowns before adjustment. However, marginal, axial, and occlusal discrepancies were similar among all materials after the adjustment.

• Composites Research
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• 제22권6호
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• pp.45-51
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• 2009

치아의 와동에 수복된 치과용 복합레진을 광(LED) 조사를 통해 경화 수축시키면서 음향방출(acoustic emission, AE)법을 이용하여 와동 벽면과 복합레진 사이의 계면상태를 실시간 해석하였다. 복합레진의 중합 수축에 의해 AE 신호들이 검출되었는데 계면 접착 상태가 나쁜 경우, 경화 수축률이 큰 초기 1분 동안 많은 AE 사상들이 관측되었으며, 이들 AE는 주파수범위가 주로 100-200kHz인 돌발형이었다. 인간치아 재질의 시편에서 발생된 AE 사상수는 스테인리스 스틸 시편보다 적었으나, PMMA 시편보다는 많았고 접착제의 도포 상태가 양호할수록 검출되는 AE 사상수는 적었다. AE 파라미터의 특성은 복합레진과 링재 사이의 접착부에서 발생하는 인장형 균열전파 및 복합레진의 수축에 따른 링재의 압축거동과 관련되었으며, 음향방출법이 치아 수복물의 접착성에 대한 비파괴 검사법으로써 유효함을 알았다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제38권
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• pp.28.1-28.6
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• 2016

Backgrounds: Insufficient intermaxillary space is caused by non-restoration following tooth extraction in the past, and this involves eruption of the opposing teeth and changes of the arch structure. Such cases are difficult just by a simple prosthetic approach, and diversified treatment plans should be established. Among these, posterior maxillary segmental osteotomy (PMSO) is an efficient treatment option than extraction of opposing teeth as it surgically repositions multiple erupted teeth and alveolar bone. PMSO can preserve the natural teeth; therefore, it is being regarded as a treatment method which can improve insufficient intermaxillary space significantly. Case presentation: In this case report, the first patient received PMSO in order to place an implant in the mandibular edentulous space after decreased vertical dimension is restored, and the second patient received PMSO along with orthodontic treatment to obtain the intermaxillary space and balance the interarch molar width. Conclusion: PMSO is the treatment of choice when occlusion is compromised in the presence of decreased vertical dimension or arch length discrepancy.