• The Journal of Advanced Prosthodontics
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• 제4권2호
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• pp.109-115
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• 2012

PURPOSE. The purpose of this clinical study was to evaluate the frequency and type of prosthetic complications in relation to type and properties of removable dentures and to investigate the influence of these complications and several data about the existing dentures on patient satisfaction. MATERIALS AND METHODS. Ninety nine patients (44 males and 55 females) wearing removable dentures have been included in the study. The complications of the patients were recorded; patient satisfaction was determined with a Visual Analog Scale (VAS) and the relationship of complications and patient satisfaction with several data about the dentures such as denture age, type of denture, centric relation and vertical dimension was investigated. Kruskal Wallis, Mann Whitney U and Chi square tests were used for statistical analyses. The results were evaluated statistically at a significance level of $P$ <.05. RESULTS. Need for addition of artificial teeth for dentures with correct centric relations was found to be significantly lower than dentures with wrong centric relations ($P$ <.01). Loss of retention, ulcerations and high vertical dimension affected the VAS chewing ability scores negatively and ulcerations affected the VAS phonation scores negatively ($P$ <.05). CONCLUSION. Considering the results of this study, it can be concluded that loss of retention, ulcerations and high vertical dimension caused patient dissatisfaction. Additionally, dentures with wrong centric relations caused need for addition of artificial teeth.

• 대한치과보철학회지
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• 제58권3호
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• pp.251-256
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• 2020

최근 치과 분야에서 디지털 기술의 발전으로 DMLS (Direct Metal Laser Sintering) 기술을 사용하여 의치의 금속구조물 제작이 가능하다. 이 방법에서 인상은 구강 스캔이나 모델 스캔으로 대체 할 수 있으며, 기존 주조 소환 방법에서 왁스 패턴은 CAD 소프트웨어에서 설계되고, 설계된 STL (standard template library) 파일을 DMLS 기법을 통해 국소의치의 최종 구성 요소를 제작할 수 있다. 치과 분야에서 디지털 기술 이용의 장점은 적합도와 정확성에 있다. 본 증례에서 지지 및 간접 유지 역할을 하는 교합면 레스트의 파절이 발생한 환자에서 DMLS 기술과 레이저 용접 기술을 사용하여 국소의치를 수리하였으며, 기능적, 심미적으로 만족스러운 결과를 보였다.

• The Journal of Advanced Prosthodontics
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• 제15권2호
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• pp.55-62
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• 2023

PURPOSE. The aim of this study is to evaluate the accuracy of removable partial denture (RPD) frameworks produced using different digital protocols. MATERIALS AND METHODS. 80 frameworks for RPDs were produced using CAD-CAM technology and divided into four groups of twenty (n = 20): Group 1, Titanium frameworks manufactured by digital metal laser sintering (DMLS); Group 2, Co-Cr frameworks manufactured by DMLS; Group 3, Polyamide PA12 castable resin manufactured by multi-jet fusion (MJF); and Group 4, Metal (Co-Cr) casting by using lost-wax technique. After the digital acquisition, eight specific areas were selected in order to measure the Δ-error value at the intaglio surface of RPD. The minimum value required for point sampling density (0.4 mm) was derived from the sensitivity analysis. The obtained Δ-error mean value was used for comparisons: 1. between different manufacturing processes; 2. between different manufacturing techniques in the same area of interest (AOI); and 3. between different AOI of the same group. RESULTS. The Δ-error mean value of each group ranged between -0.002 (Ti) and 0.041 (Co-Cr) mm. The Pearson's Chi-squared test revealed significant differences considering all groups paired two by two, except for group 3 and 4. The multiple comparison test documented a significant difference for each AOI among group 1, 3, and 4. The multiple comparison test showed significant differences among almost all different AOIs of each group. CONCLUSION. All Δ-mean error values of all digital protocols for manufacturing RPD frameworks optimally fit within the clinical tolerance limit of trueness and precision.

• 대한치과보철학회지
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• 제43권3호
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• pp.322-330
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• 2005

Statement of problem. In distal extension removable partial denture, the preservation of health of abutment teeth is very important, but abutment teeth are subjected to unfavorable stress. Purpose. The purpose of this study was to investigate the biomechanical effects of mandibular removable partial dentures with various prosthetic designs using strain gauge analysis. Material and methods. Artificial teeth of both canines were anchored bilaterally in a mandibular edentulous model made of resin. Bilateral distal extension removable partial dentures with splinted and unsplinted abutments were fabricated. Group 1 : Clasp-retained mandibular removable partial denture with unsplinted abuhnents Group 2 : Clasp-retained mandibular removable partial denture with splinted abutments by 6-unit bridge Group 3 : Bar-retained mandibular removable partial denture Strain gauges were bonded on the labial plate of the mandibular resin model, approximately 2 mm close to the abutments. Two vertical experimental loadings (100N and 200N) were applied subsequently via two miniature load cells that were placed at mandibular first molar regions. Strain measurements were performed and simultaneously monitored from a computer connected to data acquisition system. For within-group evaluations, t-test was used to compare the strain values and for between-group comparisons, a one-way analysis of variance (ANOVA) was used and Duncan test was used as post hoc comparisons. Results. Strain values increased as the applied load increased from 100N to 200N for all groups (p<.05). The strain values of group 1 and 2 were tensile under loadings. In contrast, strain values of group 3 were compressive in nature. Under 100N loading, group 1 showed higher strain values than group 3 in absolute quantity (p<.05). Under 200N loading, group 3 showed higher strain values than group 1 and 2 in absolute quantity (p<.05). Group 1 showed higher strain values than group 2 (p<.05). Conclusion. Splinting of two isolated abutments by bridge reduced the peri-abutment strain in comparison with unsplinted abutments. Strain of bar-retained removable partial denture increased much more as applied load increased, but was compressive in nature.

• 구강회복응용과학지
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• 제38권2호
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• pp.110-119
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• 2022

부분 무치악 환자의 가철성 국소의치 수복 시 지대치가 항상 유리한 위치에 존재하지는 않는다. 이로 인하여 잘 맞게 제작된 가철성 국소의치임에도 불구하고 환자는 가철성 국소의치의 안정과 지지에 대하여 만족하지 못하는 경우가 발생하게 된다. 이 때, 소수의 임플란트 크라운을 이용한 가철성 국소의치가 부분 무치악 환자에게 좋은 대안이 될 수 있다. 소수의 임플란트를 위치시키고 지대치로 이용하여 가철성 국소의치의 안정과 지지를 증가시킬 수 있다. 본 증례는 하악 편측에 잔존치를 갖는 환자에서 두개의 임플란트를 전략적으로 위치시켜 지대치를 양측으로 분포시켰다. 최종 가철성 국소의치 수복 이후 환자는 저작 기능에 만족감을 보였으며 국소의치 사용시 편안함을 나타내었다.

• 대한치과보철학회지
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• 제56권3호
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• pp.218-226
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• 2018

부분 무치악 환자에게 소수의 임플란트를 전략적인 위치에 식립하여 추가적인 유지와 지지를 얻는 임플란트 보조 국소의치(Implant-assisted removable partial denture, IARPD)를 제작할 수 있다. 최근 이러한 임플란트 보조 국소의치로 치료한 여러 증례와 임상가이드라인을 보면 후방 무치악 부위에 임플란트를 식립하는 것이 추천된다. 그러나 실제 임상에서는 구치부의 심한 치조골 흡수나 해부학적 이유로 외과적 수술(상악동거상술, 골 이식술 등)이 부가적으로 필요한 경우가 많다. 이에 대해 후방의 무치악 부위는 가철성 국소의치로 수복하되, 소수의 치아가 잔존하는 전방 무치악 부위는 임플란트 고정성 보철물로 수복하여 지대주로 활용하는 치료방법이 대안으로 제시될 수 있다. 본 증례는 상악 구치부 치아의 상실과 잔존치열에 중등도 이상의 마모를 보이는 환자에 대한 증례로 상악 전방부에 3개의 임플란트를 식립하고 잔존하는 상악 전치부 자연치와 더불어 각각 써베이드 고정성 보철물을 제작하였으며 상악 후방연장 국소의치를 제작하였다. 그와 함께 손상된 하악 자연치는 고정성 보철물로 전악수복하였다. 이로써 감소된 수직고경 및 붕괴된 교합평면을 회복하여 기능적, 심미적으로 향상되었으며 지속적인 경과관찰 중이다. 본 증례를 통해 전방부 임플란트 써베이드 고정성 보철물과 후방연장 국소의치에 의한 보철치료 증례의 3년 경과관찰 결과를 보고하고자 한다.

• 대한치과보철학회지
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• 제36권1호
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• pp.81-103
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• 1998

The purpose of this study was to compare and evaluate the differences in masticatory performance, muscle activity, and patterns of occlusal contact between persons with natural dentition and removable partial denture wearers. Twenty healthy adult subjects with more than 28 teeth and thirteen removable partial denture wearers that classified Kennedy classification I was selected. The degree of pulverized rice and peanut was measured and analyzed by means of sieving method to compare the masticatory performance. For the muscle activity, EMG was recorded in selected muscles(Temporalis and masseter muscle) during mastication and resting state. The occlusal record in maximal intercuspation was taken with a silicone occlusal bite registration material for analysis of the patterns of occlusal contact. The obtained results were as follows: 1. When chewed peanuts, masticatory performance ratio at 10-sieve size was 81.31% in natural dentition group. In removable partial denture wearer, 27.01% without RPD and 69.09% with RPD. When chewed rice, 42.04%, 11.87%, and 21.58%, respectively. The differences of masticatory performance ratio between groups were statistically significant at the 0.05 level. 2. The mean EMG value in resting state was $1.06{\mu}V$ on temporal muscle, $0.98{\mu}V$ on masseter muscle in natural dentition group. In removable partial denture wearers, $1.13{\mu}V$ on temporal muscle, $1.05{\mu}V$ on masseter muscle without RPD and $1.11{\mu}V$ on temporal muscle, $1.04{\mu}V$ on masseter muscle with RPD. 3. The mean EMG value during mastication was $45.64{\mu}V$ in natural dentition group, and in removable partial denture wearers, $22.06{\mu}V$ without RPD and $31.01{\mu}V$ with RPD when chewed peanuts. When chewed rice, $45.24{\mu}V,\;25.53{\mu}V\;and\;32.14{\mu}V$, respectively. The differences of mean masticatory EMG value between groups were statistically significant at the 0.05 level. 4. The number of posterior occlusal contact point was 20.15 in natural dentition group and 11.92 in removable partial denture wearers. The area of perforated surface was $16.50mm^2$ in natural dentition group and $6.06mm^2$ in removable partial denture wearers. The area of contact surface was $78.93mm^2,\;51.52mm^2$, respectively. 5. The area of contact surface was effective to masticatory performance ratio in natural dentition group and removable partial denture wearers (p<0.05). From these results, it is concluded that in partially edentulous patient, masticatory efficiency can be improved by removable partial denture wearing, and for efficient mastication, tight occlusal contact surface shoud be maintained by maximum support that is provided from mucosa.

• 대한치과보철학회:학술대회논문집
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• 대한치과보철학회 1999년도 Asian Academy of Prosthodntics. Korean Academy of Prosthodontics
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• pp.58-58
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• 1999

• 대한치과보철학회:학술대회논문집
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• 대한치과보철학회 1999년도 창립 40주년 기념 추계학술대회
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• pp.105-105
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• 1999

• 대한치과보철학회지
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• 제33권2호
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• pp.241-268
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• 1995

Splint therapy, the immobilization of teeth, has been done for patient's masticatory comforts and an adjunctive aid in periodontal therapy. Mandibular premolars are frequently splinted in many distal extension removable partial denture cases. But splinting is an extensive restoration that may not be conservative of tooth structure and may prove to be quite costly to the patient. The two dimensional finite element analysis method was used to determine the magnitude and mode of distribution of the stresses of the periodontal ligament and supporting alveolar bone when abutments with different periodontal supports were splinted and distal-extension removable partial denture was subjected to different loading schemes. The results were as follows : 1. When abutments were splinted, stresses moved from apico-distal to apico-mesial of terminal abutment on a vertical force and from disto-alveolar crest to apex on a distally directed force. But stresses were generally diminished on a mesially directed force. 2. As vertical bone loss was proceeding, most of stresses were transmitted to residual ridge and the rest of stresses were concentrated on apex of distal abutment. But these apical stresses were minimized when abutments were splinted. 3. As mesially inclined bone loss was proceeding, it seemed to be dangerous that many stresses were concentrated on the distal alveolar crest, especially in the distally directed load case. Abutments splinting decreased the alveolar crestal stresses but not enough. 4. For all vertical stresses were effectively decreased on splinting, stresses were concentrated as highly on apico-mesial area of distal abutment in distally directed load cases as the distal inclination of bone level was severe. 5. The directions and magnitudes of abutment movements were decreased with teeth splinting.