• 대한치과보철학회지
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• 제45권5호
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• pp.579-588
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• 2007

Statement of problem: A tenderness of the dentin after tapering of teeth for dental prosthesis is a common phenomenon. In practice, the alternative desensitizer may be used for minor pain after tapering of teeth. Purpose: In this study, the desensitizers were used to investigate the affect decreasing of shear bond strength according to the use of various cement, such as resin, Glass Ionomer, and phosphate cement. Material and method: Three different desensitizers were used on this study Compositions of two dentin desensitizers were HEMA(hydroxyethylmethacrylate) and glutaraldehyde. The other one is oxalic acid. Three dentin desensitizers applied on 12 degrees taper teeth. Then, Ni-Cr crowns were bonded with Resin cement, Zinc Phosphate (ZPC) cement and Glass Ionomer (GIC) cement. 120 human premolar teeth were used for specimens. The specimens were divided into four group as the reference and the empirical each with thirty specimens, then further divided into 12 group according to type of desensitizers and cement types. The shear bond strength were measured by Instron multi task instrument. Results: According to the result, the measured shear bond strength in order from the weakest to the strongest in general was ZPC, Resin, and GIC. And it is found that the application of desensitizers on dentin surface does not affect the shear bond strength. Conclusion: Dentin desensitizers that alleviate or prevent a dentin tenderness, usually contains HEMA and glutaraldehyde compounds. Such desensitizers are widely used in clinical studies. By applying the dentin desensitizer on the exposed dentin surface, the dentin capillary are blocked and periodontal membrane and cementum can not be drawn in pulp cavity. Since HEMA and glutaraldehyde may cause harm to the pulp cavity, an alternative desensitizer was developed.

• 구강회복응용과학지
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• 제30권1호
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• pp.81-92
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• 2014

상악 전치부에 임플란트를 이용해 심미적으로 수복 하는 것은 많은 어려움이 따른다. 이는 치조골 흡수와 치간 유두 수축 등과 같은 임플란트 주변 경, 연조직 문제와 금속지대주 및 금속도재관의 변연노출과 낮은 광투과도 등의 보철적 한계 때문이다. 이에 본 증례에서는 경, 연조직의 증대술 및 성형술, 발치 후 즉시 식립 등과 함께 임시수복물의 장기간 사용 및 수정으로 임플란트 주위 연조직의 형태와 건강을 형성한 후, 맞춤형 인상 코핑을 사용하여 이를 최종 모형에 재현하였다. 또한 맞춤형 지르코니아 지대주와 완전 도재관을 이용해 최종 수복함으로써 기능적이고 심미적인 결과를 얻었기에 이를 보고하고자 한다.

• 대한치과보철학회지
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• 제33권1호
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• pp.75-84
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• 1995

This study was designed as a reference of vertical dimension in prosthetic treatment. The author analyzed six facial measurements, namely, (1) the height of lower face at maximum intercuspal position, (2) the height of lower face at resting position, (3) midface, (4) external ear and lateral wall of orbit, (5) interpupillary distance, (6) distance between pupil and mouth in the 100 Won-kwang Univ. Dental collage students(50 : male, 50 : female), who have normal occlusion, no posterior prosthesis, no experience of orthodontic treatment, and no deformity of facial soft tissue and no temporomandibular dysfunction. The results of this study were as follows : 1. The length of midface was shortest and the inter-pupillary distance was longest in both male and female. 2. The length difference with the length of midface and lower face at maximum intercuspal position was 5.64mm in male and 2.23mm in female, so the lower face was longer, 3. The facial measuring component, similar to lower face at maximum intercuspation, was the length of between medial wall of external ear and lateral wall of orbit. It's difference was 1.3mm in male, 1.77mm in female, and the lower face was shorter. 4. The difference of lower facial length in resting position and maximum intercuspation was 2.48mm in male, 2.24mm in female, the length of resting position was therefore longer. 5. The most clost correlation with the height of maximum intercuspal positioning lower face was resting lower face in both groups.

• 대한치과보철학회지
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• 제38권4호
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• pp.544-551
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• 2000

A fabrication method of inner and outer crown using CAD/CAM is presented. The information of abutment teeth is transferred to a computer through a 3-dimensional scanner. A Konus inner and outer crown is designed on a computer and a real crown is machined based on this design using CAM. This method can save laboratory time and reduce inaccuracies compare to conventional casting procedure. A stone model with six prepared abutment teeth from a patient was used in this study. Three dimensional information from the model was transferred to a computer using a contact type 3-dimensional scanner with a $25{\mu}m$ accuracy. All margins were identified on a computer image where there is a change in surface taper of a model. To provide a cement space, the image of a inner sur face of a Konus inner crown was duplicated $25{\mu}m$ apart from the surface of a prepared abutment teeth image. The cement space was $20{\mu}m$ at the cervical margin. All Konus crowns were machined with a $10{\mu}m$ accuracy. It was concluded that this method can reduce working-time for the laboratory process and increase accuracy. A further research is required to make a simplified process for a more complex prosthesis.

• 구강회복응용과학지
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• 제32권3호
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• pp.214-223
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• 2016

임플란트를 보조적으로 이용함으로써 후방 연장 국소의치에 부가적으로 유지와 지지를 얻는 임플란트 보조 국소의치(implant-assisted RPD, IARPD)에 대한 관심이 증가하고 있다. 본 증례는 장기간 후방연장 국소의치의 사용으로 인하여 심하게 기울어진 교합평면을 가진 부분 무치악 환자에서 상악의 고정성 보철 수복과 하악의 지르코니아 교합면을 가지는 임플란트 보조 국소의치를 이용하여 심미적이며 장기적으로 안정적인 교합평면을 가지도록 전악 수복하였으며, 기능적으로 만족스러운 결과를 얻었기에 이를 보고하고자 한다.

• 대한심미치과학회지
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• 제25권1호
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• pp.25-34
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• 2016

상실한 하악 4전치에서의 치료 계획은 어느 다른 부위보다 수술의 성공률이나 보철치료시 유리한 환경을 지니고 있다고 흔히 생각되는 부위이다. 하지만 하악 전치들의 M-D 사이즈나 crowding으로 인한 공간적 제한, 임시치아 문제, 치조골 흡수로 인해 생기는 심미적인 문제 등 의외로 까다로운 경우가 종종 발생하는 부위기도 한다. 본문에서는 하악 4전치 상실 시의 치료 계확에 대해서 케이스를 통해 알아 보겠다. 하악 4전치 상실시 가능한 옵션들: 하나 혹은 4전치중 일부 상실의 경우나 잔존 치조골의 흡수가 거의 없어 임플란트 위치 관계가 심미적으로 중요하다고 판단되는 경우라면 직경이 작은 임플란트들을 원래 발치와 중앙에 식립(Narrow type 이나 One body mini implant type) 최종 보철물 형태가 Pink porcelain을 포함하는 이미 광범위한 치조골의 흡수가 일어난 경우 즉 임플란트 식립 위치가 덜 중요한 상황이라면 regular size의 임플란트들을 측절치와 중절치의 사이 Interseptal bone위치에 식립 4전치중 하나 혹은 일부가 상실됐고 남아 있는 전치들의 예후가 불량하다고 의심되나 환자가 당장 나머지 전치들의 발치에는 동의하지 않을 때 남아 있는 전치들이 발치 될 때까지의 Tentative restoration로서 Resin Bonded Bridge(Resin Retained Bridge/Resin Bonded Fixed Partial Denture)의 적용.

• The Journal of Advanced Prosthodontics
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• 제4권4호
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• pp.218-226
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• 2012

PURPOSE. The purpose of this study was to propose finite element (FE) modeling methods for predicting stress distributions on teeth and mandible under chewing action. MATERIALS AND METHODS. For FE model generation, CT images of skull were translated into 3D FE models, and static analysis was performed considering linear material behaviors and nonlinear geometrical effect. To find out proper boundary and loading conditions, parametric studies were performed with various areas and directions of restraints and loading. The loading directions are prescribed to be same as direction of masseter muscle, which was referred from anatomy chart and CT image. From the analysis, strain and stress distributions of teeth and mandible were obtained and compared with experimental data for model validation. RESULTS. As a result of FE analysis, the optimized boundary condition was chosen such that 8 teeth were fixed in all directions and condyloid process was fixed in all directions except for forward and backward directions. Also, fixing a part of mandible in a lateral direction, where medial pterygoid muscle was attached, gave the more proper analytical results. Loading was prescribed in a same direction as masseter muscle. The tendency of strain distributions between the teeth predicted from the proposed model were compared with experimental results and showed good agreements. CONCLUSION. This study proposes cost efficient FE modeling method for predicting stress distributions on teeth and mandible under chewing action. The proposed modeling method is validated with experimental data and can further be used to evaluate structural safety of dental prosthesis.

• The Journal of Advanced Prosthodontics
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• 제5권1호
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• pp.21-28
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• 2013

PURPOSE. This study examined the effects of the abutment types and dynamic loading on the stability of implant prostheses with three types of implant abutments prepared using different fabrication methods by measuring removal torque both before and after dynamic loading. MATERIALS AND METHODS. Three groups of abutments were produced using different types of fabrication methods; stock abutment, gold cast abutment, and CAD/CAM custom abutment. A customized jig was fabricated to apply the load at $30^{\circ}$ to the long axis. The implant fixtures were fixed to the jig, and connected to the abutments with a 30 Ncm tightening torque. A sine curved dynamic load was applied for $10^5$ cycles between 25 and 250 N at 14 Hz. Removal torque before loading and after loading were evaluated. The SPSS was used for statistical analysis of the results. A Kruskal-Wallis test was performed to compare screw loosening between the abutment systems. A Wilcoxon signed-rank test was performed to compare screw loosening between before and after loading in each group (${\alpha}$=0.05). RESULTS. Removal torque value before loading and after loading was the highest in stock abutment, which was then followed by gold cast abutment and CAD/CAM custom abutment, but there were no significant differences. CONCLUSION. The abutment types did not have a significant influence on short term screw loosening. On the other hand, after $10^5$ cycles dynamic loading, CAD/CAM custom abutment affected the initial screw loosening, but stock abutment and gold cast abutment did not.

• 대한치과교정학회지
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• 제49권6호
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• pp.413-426
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• 2019

This study was performed to describe the longitudinal management of recurrent temporomandibular joint (TMJ) ankylosis from infancy to adulthood in perspective of surgical and orthodontic treatment. A 2-year-old girl was referred with chief complaints of restricted mouth opening and micrognathia due to bilateral TMJ ankylosis. For stage I treatment during early childhood (6 years old), high condylectomy and interpositional arthroplasty were performed. However, TMJ ankylosis recurred and symptoms of obstructive sleep apnea (OSA) developed. For stage II treatment during early adolescence (12 years old), gap arthroplasty, coronoidectomy, bilateral mandibular distraction osteogenesis, and orthodontic treatment with extraction of the four first premolars were performed. However, TMJ ankylosis recurred. Because the OSA symptoms reappeared, she began to use a continuous positive airway pressure device. For stage III treatment after completion of growth (20 years old), low condylectomy, coronoidectomy, reconstruction of the bilateral TMJs with artificial prostheses along with counterclockwise rotational advancement of the mandible, genioglossus advancement, and orthodontic treatment were performed. After stage III treatment, the amount of mouth opening exhibited a significant increase. Mandibular advancement and ramus lengthening resulted in significant improvement in the facial profile, Class I relationships, and normal overbite/overjet. The OSA symptoms were also relieved. These outcomes were stable at the one-year follow-up visit. Since the treatment modalities for TMJ ankylosis differ according to the duration of ankylosis, patient age, and degree of deformity, the treatment flowchart suggested in this report could be used as an effective guideline for determining the appropriate timing and methods for the treatment of TMJ ankylosis.

• 대한치과보철학회지
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• 제60권2호
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• pp.187-194
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• 2022

완전 무치악 환자의 가철성 보철 수복 치료에서 잔존 치조제의 흡수가 심한 경우 임플란트를 이용하면 부가적인 지지, 유지 및 안정을 제공할 수 있다. 환자의 상태에 대한 정확한 진단 및 평가 없이 보철물을 제작하게 되면 생역학적, 기능적, 심미적으로 불리한 치료 결과를 야기하게 된다. 본 증례의 환자는 개인치과의원에서 상·하악 임플란트 피개의치를 제작하였으나 연조직 통증 및 기존 의치 유지력 저하로 재치료를 위해 내원하였다. 진단 결과 기존 의치의 수직고경이 다소 낮게 설정되어 있어 이를 거상하고, milled bar와 부가적인 attachment를 이용한 임플란트 피개의치를 제작하였다. 이를 통해 증진된 구강위생과 기능적, 심미적인 면에서 만족할 만한 결과를 얻었기에 보고하는 바이다.