• 대한치과의사협회지
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• 제48권9호
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• pp.654-663
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• 2010

The success in periodontal-prosthetic therapy lies in patient satisfaction with subjective and customized treatment regimen that has been refined for individual needs. To fulfill these requirements, multiple predictors may have to be taken into consideration in the comprehensive treatment planning. Incorporation of complex factors that guarantee the evidence-based therapy would include, but not limited to, osseous morphology, biotype of gingival around abutment, bone morphology of interdental bone and those around furcation area, abutment or bridge mobility. The periodontal-restorative interface should be of mutually protective. Also strategic and esthetic value of abutment teeth to be restored should also be taken into consideration. Taken together, all these should work in concert to enhance the predictability and longevity of abutment teeth in periodontal-prosthetic therapy.

• 대한심미치과학회지
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• 제21권1호
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• pp.51-60
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• 2012

• The Journal of Advanced Prosthodontics
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• 제6권3호
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• pp.233-240
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• 2014

PURPOSE. To evaluate the effects of different abutment geometries in combination with varying luting agents and the effectiveness of different cleaning methods (prior to re-cementation) regarding the retentiveness of zirconia copings on implants. MATERIALS AND METHODS. Implants were embedded in resin blocks. Three groups of titanium abutments (pre-fabricated, height: 7.5 mm, taper: $5.7^{\circ}$; customized-long, height: 6.79 mm, taper: $4.8^{\circ}$; customized-short, height: 4.31 mm, taper: $4.8^{\circ}$) were used for luting of CAD/CAM-fabricated zirconia copings with a semi-permanent (Telio CS) and a provisional cement (TempBond NE). Retention forces were evaluated using a universal testing machine. Furthermore, the influence of cleaning methods (manually, manually in combination with ultrasonic bath or sandblasting) prior to re-cementation with a provisional cement (TempBond NE) was investigated with the pre-fabricated titanium abutments (height: 7.5 mm, taper: $5.7^{\circ}$) and SEM-analysis of inner surfaces of the copings was performed. Significant differences were determined via two-way ANOVA. RESULTS. Significant interactions between abutment geometry and luting agent were observed. TempBond NE showed the highest level of retentiveness on customized-long abutments, but was negatively affected by other abutment geometries. In contrast, luting with Telio CS demonstrated consistent results irrespective of the varying abutment geometries. Manual cleaning in combination with an ultrasonic bath was the only cleaning method tested prior to re-cementation that revealed retentiveness levels not inferior to primary cementation. CONCLUSION. No superiority for one of the two cements could be demonstrated because their influences on retentive strength are also depending on abutment geometry. Only manual cleaning in combination with an ultrasonic bath offers retentiveness levels after re-cementation comparable to those of primary luting.

• 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.

• The Journal of Advanced Prosthodontics
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• 제10권5호
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• pp.388-394
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• 2018

PURPOSE. To measure axial displacement of different implant-abutment connection types and materials during screw tightening at the recommended torque by using a contact scanner for two-dimensional (2D) and three-dimensional (3D) analyses. MATERIALS AND METHODS. Twenty models of missing mandibular left second premolars were 3D-printed and implant fixtures were placed at the same position by using a surgical guide. External and internal fixtures were used. Three implant-abutment internal connection (INT) types and one implant-abutment external connection (EXT) type were prepared. Two of the INT types used titanium abutment and zirconia abutment; the other INT type was a customized abutment, fabricated by using a computer-controlled milling machine. The EXT type used titanium abutment. Screws were tightened at $10N{\cdot}cm$, simulating hand tightening, and then at the manufacturers' recommended torque ($30N{\cdot}cm$) 10 min later. Abutments and adjacent teeth were subsequently scanned with a contact scanner for 2D and 3D analyses using a 3D inspection software. RESULTS. Significant differences were observed in axial displacement according to the type of implant-abutment connection (P<.001). Vertical displacement of abutments was greater than overall displacement, and significant differences in vertical and overall displacement were observed among the four connection types (P<.05). CONCLUSION. Displacement according to connection type and material should be considered in choosing an implant abutment. When adjusting a prosthesis, tightening the screw at the manufacturers' recommended torque is advisable, rather than the level of hand tightening.

• 대한치과보철학회지
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• 제54권2호
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• pp.146-151
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• 2016

상악 완전 무치악에 6개 이상의 임플란트가 식립된 경우 임플란트-지지형 피개의치 제작이 가능하다. 임플란트-지지 피개의치에 사용되는 다양한 부착장치 중에 milled-bar의 경우 의치의 회전을 허용하지 않고, 안정성이 뛰어나며, 여러 개의 임플란트를 연결 고정하는 효과를 가진다는 장점이 있다. 본 증례에서는 전치부에 심한 골소실을 동반한 상악 완전 무치악 환자에서 세 가지 다른 시스템으로 구성된 7개의 임플란트 상부에 CAD/CAM 맞춤형 지대주와 시멘트 접착형의 milled bar를 이용한 피개의치를 제작하여 상실된 심미와 기능을 효과적으로 회복하였다.

• The Journal of Advanced Prosthodontics
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• 제8권1호
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• pp.62-69
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• 2016

PURPOSE. The purpose of this study was to evaluate the effects of abutment screw length and cyclic loading on the removal torque (RTV) in external hex (EH) and internal hex (IH) implants. MATERIALS AND METHODS. Forty screw-retained single crowns were connected to external and internal hex implants. The prepared titanium abutment screws were classified into 8 groups based on the number of threads (n = 5 per group): EH 12.5, 6.5, 3.5, 2.5 and IH 6.5, 5, 3.5, 2.5 threads. The abutment screws were tightened with 20 Ncm torque twice with 10-minute intervals. After 5 minutes, the initial RTVs of the abutment screws were measured with a digital torque gauge (MGT12). A customized jig was constructed to apply a load along the implant long axis at the central fossa of the maxillary first molar. The post-loading RTVs were measured after 16,000 cycles of mechanical loading with 50 N at a 1-Hz frequency. Statistical analysis included one-way analysis of variance and paired t-tests. RESULTS. The post-loading RTVs were significantly lower than the initial RTVs in the EH 2.5 thread and IH 2.5 thread groups (P<.05). The initial RTVs exhibited no significant differences among the 8 groups, whereas the post-loading RTVs of the EH 6.5 and EH 3.5 thread groups were higher than those of the IH 3.5 thread group (P<.05). CONCLUSION. Within the limitations of this study, the external hex implants with short screw lengths were more advantageous than internal hex implants with short screw lengths in torque maintenance after cyclic loading.

• 구강회복응용과학지
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• 제28권2호
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• pp.201-212
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• 2012

임플란트 주위조직과 치아 주위조직은 조직학, 형태학적으로 유사한 면이 있다. 특히 functional ankylosis라 불리는 티타늄과 연조직의 직접적인 상피부착은 치아주위 조직의 접합상피처럼 염증세포의 치근단으로의 이행 및 그로 인한 골흡수를 막는 역할을 한다. 그러나 반복적인 지대주의 착탈은 임플란트 주위 연조직의 mucosal barrier를 파괴하여 골흡수를 야기할 수 있다. 만일 지대주의 반복적인 착탈 없이 수술 시에 보철 지대주를 채결한다면 골흡수의 양을 줄일 수 있을 것이다. 이는 기존의 수술방법으로는 한계가 있었으나 Cone Beam Computed Tomography(CBCT)를 이용한 guided surgery를 이용함으로써 임플란트 식립의 3차원적 정확성의 비약적인 향상으로 이런 술식이 가능하게 되었다. 본 증례는 정밀한 CBCT를 통한 분석 후 지르코니아 맞춤 지대주를 미리 제작하고 수술 시에 즉시 지대주와 임시보철물을 연결한 경우로 임상적으로 만족할만한 결과를 얻어 이를 보고하는 바이다.

• 대한치과보철학회지
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• 제39권3호
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• pp.306-312
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• 2001

Achieving an aesthetic implant-supported restoration in the single tooth missing case can be challenging when the implant site is in e anterior region. The objective of this report is to focus on presurgical evaluation of implant site and systematic development of related prosthetic modalities. An accurate diagnostic evaluation, a systematically developed pesurgical plan, and knowledge and clinical skill of the various related therapeutic modalities are indispensible. Collection of patient's information, appropriate abutment selection, soft tissue contour, implant axis, and occlusion need to be discussed for aesthetic clinical outcome. For aesthetic restoration, such as surgical guide stent for precise implant positioning customized provisional restoration for development of optimal periimplant soft tissue contours, and fabrication customized abutment (mesiostructure) for veriable emergence profile, are recommended.

• 구강회복응용과학지
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• 제31권4호
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• pp.364-370
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• 2015

최근 구치부 부분 무치악 환자의 임플란트 보철 수복은 기능적뿐만 아니라 심미적으로도 환자의 만족을 이끌어내야 하는 과제를 안고 있다. 이렇게 환자의 요구가 높아지면서 상실된 자연치아와 유사한 형태의 임플란트 보철을 사용한 구강회복이 보철수복의 중요한 이슈가 되고 있다. 이를 위해서는 기성 지대주 보다는 더 넓은 customized CAD/CAM 지대주를 사용함으로써 자연스러운 출현윤곽을 재현할 수 있다. 넓은 지대주를 지지해주기 위해서는 충분한 폭과 높이를 가지는 각화치은이 존재해야 하는데, 만약 긴 치아상실기간이나 골이식술 등으로 인해 임플란트 주위에 각화치은이 부족한 경우에는 연조직 증대술을 시행하는 것이 추천된다. 이러한 과정을 통해 심미적이고 기능적인 임플란트 보철 제작이 가능하며 구강위생관리를 용이하게 하고 향후 임플란트 주위염의 발생 가능성을 감소시킨다. 본 증례는 구치부 부분 무치악 환자에서 골이식술, 상악동 이식술, 임플란트 식립술 및 연조직 이식술을 사용하여 부족한 치조골과 각화치은 및 협측전정을 회복하였으며, customized CAD/CAM 지대주와 지르코니아 보철물을 이용하여 수복한 증례로 주기적인 내원 및 검사를 통해 기능적, 심미적으로 만족할만한 결과를 얻었기에 이 사례를 보고하고자 한다.