• 대한치과보철학회지
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• 제42권4호
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• pp.397-411
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• 2004

Purpose: The purpose of this study was to determine the effect of anchorage systems and palatal coverage of denture base on load transfer in maxillary implant-supported overdenture. Material and methods: Maxillary implant -supported overdentures in which 4 implants were placed in the anterior region of edentulous maxilla were fabricated, and stress distribution patterns in implant supporting bone in the case of unilateral vertical loading on maxillary right first molar were compared with each other depending on various types of anchorage system and palatal coverage extent of denture base using three-dimensional photoelastic stress analysis. Two photoelastic overdenture models were fabricated in each anchorage system to compare with the palatal coverage extent of denture base, as a result we got eight models : Hader bar using clips(type 1), cantilevered Hader bar using clips(type 2), Hader bar using clip and ERA attachments(type 3), cantilevered milled-bar using swivel-latchs and frictional pins(type 4). Result: 1. In all experimental models, the highest stress was concentrated on the most distal implant supporting bone on loaded side. 2. In every experimental models with or without palatal coverage of denture base, maximum fringe orders on the distal ipsilateral implant supporting bone in an ascending order is as follows; type 3, type 1, type 4, and type 2. 3. Each implants showed compressive stresses in all experimental models with palatal coverage of denture base, but in the case of those without palatal coverage of denture base, tensile stresses were observed in the distal contralateral implant supporting bone. 4. In all anchorage system without palatal coverage of denture base, higher stresses were concentrated on the most distal implant supporting bone on loaded side. 5. The type of anchorage system affected in load transfer more than palatal coverage extent of the denture base. Conclusion: To the results mentioned above, in the case of patients with unfavorable biomechanical conditions such as not sufficient number of supporting implants, short length of the implant, and poor bone quality, selecting a resilient type attachment or minimizing the distal cantilevered bar is considered to be an appropriate method to prevent overloading on implants by reducing cantilever effect and gaining more support from the distal residual ridge.

• 대한치과보철학회지
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• 제53권2호
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• pp.150-156
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• 2015

부분 혹은 완전 무치악 환자에서 임플란트 치료가 보편화됨에 따라, 복합적인 전신질환이 있는 고령 환자들도 전통적인 총의치보다 임플란트-지지-고정성 보철물이나, 임플란트-유지-가철성 보철물을 선호하는 경향이 높아지고 있다. 본 증례의 환자는 77세 여성 환자로, 내원 당시 만성 고혈압으로 아스피린을 포함한 혈압약과 bisphosphonate 계열의 골다공증 약을 장기 복용 중이었으며, 상 하악 치조골 흡수량이 상당하였고 비대칭이 심하였다. 또한 2년 전 뇌졸중 진단을 받은 후, 우측 상반신마비로 인하여 좌측의 편측 저작만 가능하며, 팔 또한 좌측만 사용할 수 있는 상태(hemi-syndrome)이다. 초진 시 하악 총의치의 재제작만을 원하였으나, 상악 역시 잔존 치아들의 상태가 불량하여 치근을 이용할 수 있는 2개 치아를 제외한 나머지 치아들을 발거 후 치근에 의해 유지되는 피개의치를 계획하였으며, 하악에는 임플란트를 식립 후 그에 유지되는 피개의치를 계획하였다. 유지장치로는, 한 손으로도 쉽게 의치의 착탈이 가능한 자석을 선택하였다. 복용 중인 약의 전략적 중단을 통해 상악의 발치와 하악의 임플란트 식립을 시행하였고, 3개월 후 평가에서 임플란트가 주위 변연골 소실 없이 잘 유지되고 있어 자석을 이용한 피개의치를 제작, 장착하였다. 5개월 정기 검진까지 시행한 결과, 주목할 만한 합병증 없이 저작 기능 및 발음, 심미면에서 만족할 만한 결과를 얻었기에 보고하는 바이다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제33권3호
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• pp.249-255
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• 2011

Purpose: Placement of endosseous implants in the atrophic maxilla is often restricted because of the lack of supporting bone. In this article, augmentation of the maxillary sinus floor with deproteinized bovine bone to enable insertion of endosseous implants is described. The technique is aimed at providing a cortical layer on top of the graft to ensure a reliable seal of the maxillary sinus and to achieve optimal stability of the bone graft in case of simultaneously placement of dental implants. Methods: The procedure was used in 200 patients (839 implants), using deproteinized bovine bone. The mean follow-up was 28.5 months. No inflammation of the bone grafts nor of the maxillary sinus occurred. The patients received implant supported overdentures or bone-anchored bridges. Results: The survival rate of implant restoration of this study was 97.6%. The total average of marginal bone loss in radiographs was $0.20{\pm}0.38$ mm. Insufficient primary stability, bony quality, and infection were thought to be associated factors in the failed cases. Conclusion: This study documented that deproteinized bovine bone, when used as a grafting material for augmentation of the sinus floor, may lead to proper osseointegration of a endosseous implant.

• Journal of Periodontal and Implant Science
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• 제43권1호
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• pp.12-17
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• 2013

The purpose of this review is to examine the performance of attachments used in implant-supported overdenture (IOD) in both clinical and in vitro settings and report the compiled findings, comparisons, and trends in the research literature. Articles published in PubMed on IOD attachment systems and performance were reviewed. Non-original articles were excluded. For each article included, the type of study, number of implants, number of attachment systems, and study outcome were recorded. Of the 283 articles found, 158 met the inclusion criteria. Ninety-four articles were clinical studies and 64 articles were in vitro studies. Studies on retention were the most common for in vitro studies, and four or more attachment systems were compared in most articles with significant differences in outcome. A clinical outcome of one attachment system was most common for clinical studies, while most studies had neutral outcomes overall. Ball attachment was the most commonly tested IOD attachment system. The trend in the literature showed that there is a large discrepancy between the study designs and outcomes between the clinical and the in vitro studies for IOD. Further clinical studies that can validate in vitro research should be encouraged to address this discrepancy between the two areas.

• The Journal of Advanced Prosthodontics
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• 제7권1호
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• pp.32-38
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• 2015

PURPOSE. The aim of this study was to compare the durability and retention of 4 types of attachments placed over computer aided design/computer aided manufacturing (CAD/CAM) titanium bars when subjected to different pH conditions. MATERIALS AND METHODS. Four commercially available attachments were investigated: Hader Yellow, Hader Red, Ackerman Gold and Ackerman Stainless Steel. These attachments and Ackerman CAD/CAM titanium bars were placed in 2 vessels containing different artificial saliva solutions (pH 7/pH 4) at $37^{\circ}C$ for one month to simulate corrosion conditions, and they were then subjected to mechanical testing (5400 cycles of insertion and removal). RESULTS. The results revealed that there were significant differences in the average values of insertion/removal force due to the pH (F (1, 24)=9.207, P<.05) and the type of attachment (F (3, 24)=11.742, P<.05). CONCLUSION. More acidic pH values were found to have a negative influence on the retention capacity of the attachments.

• The Journal of Advanced Prosthodontics
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• 제5권3호
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• pp.333-340
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• 2013

PURPOSE. This study was accomplished to assess the biomechanical state of different retaining methods of bar implant-overdenture. MATERIALS AND METHODS. Two 3D finite element models were designed. The first model included implant overdenture retained by Hader-clip attachment, while the second model included two extracoronal resilient attachment (ERA) studs added distally to Hader splint bar. A non-linear frictional contact type was assumed between overdentures and mucosa to represent sliding and rotational movements among different attachment components. A 200 N was applied at the molar region unilaterally and perpendicular to the occlusal plane. Additionally, the mandible was restrained at their ramus ends. The maximum equivalent stress and strain (von Mises) were recorded and analyzed at the bone-implant interface level. RESULTS. The values of von Mises stress and strain of the first model at bone-implant interface were higher than their counterparts of the second model. Stress concentration and high value of strain were recognized surrounding implant of the unloaded side in both models. CONCLUSION. There were different patterns of stress-strain distribution at bone-implant interface between the studied attachment designs. Hader bar-clip attachment showed better biomechanical behavior than adding ERA studs distal to hader bar.

• 대한치과보철학회지
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• 제37권1호
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• pp.93-103
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• 1999

Stress distribution on mandibular implants supporting overdentures were registered in vitro experimental model by means of 4 rosette gauges which were placed around the implant. The overdenture attachments used in this study were the Resilient Dolder bar, Rigid Bolder bar, Round bar, Hader bar & Dal-Ro attachment. An occlusal jig was placed on the overdenture and the loading sites were 3 points which mimicked working, balancing, and median relations. With 5 and 10kg loading, strains were measured by strain indicator(P-3500, Measurement group, Raleigh, USA), and using these data, maximum and minimum principal stresses and Von Mises stress were calculated and evaluated. The results were as follows : There was a tendency of high stress concentration in the lingual side of the implant, and in the buccal side low stress was developed regardless of the attachment systems. The resilient Bolder bar concentrated highest stress among the attachment systems, and the Round bar and the Dal-Ro attachment provided comparatively low stresses around the implant. The rigid Bolder bar concentrated high stress in the mesial side, and the Dal-Ro attachment developed tensile stress patterns in the lingual and distal sides of the implant at the balancing relation.

• 대한치과보철학회지
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• 제59권1호
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• pp.36-42
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• 2021

하악 무치악 환자에게 치과용 임플란트를 이용한 피개의치가 우선적으로 추천된다. 그러나 많은 환자들은 경제적, 건강상태를 이유로 전통적인 총의치를 선택하기도 한다. 전통적인 방법으로 제작된 총의치는 치조골 흡수가 심한 환자에서 간혹 유지 및 안정에 한계를 보인다. 이런 한계를 극복하기 위해서 폐구인상법을 이용한 흡착의치가 사용되고 있다. 그러나 기존의 방법은 Frame cut back tray, Centric tray, Gnathometer M이 필요하다. 본 논문은 진료실에서 흔히 사용되는 치과재료를 이용한 하악 흡착의치 제작과정을 소개하고자 한다.

• 대한치과기공학회지
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• 제45권3호
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• pp.61-66
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• 2023

Purpose: The current study examined the retention and wear resistance of stud-type attachments made of high-performance polyetheretherketone (PEEK) or polyetherketoneketone (PEKK) from the polyaryletherketones (PAEKs) family. Methods: The study sample included 10 PEEK or PEKK attachments that were mounted onto their male parts, designed on the upper aspect of the attachment, with a load of 30 N. Tensile stress was applied using an Instron machine to separate the male and female parts, and the maximum tensile stress to be applied was determined based on the retention force observed. The wear resistances of PEEK and PEKK were evaluated by measuring the inner diameter of the inserted female part 10 times. Results: The maximum tensile stresses of PEEK and PEKK were 56.26±0.58 and 69.12±0.92 N, respectively, with the maximum stress required to remove the PEKK specimens from the abutment being 12.86 N higher than that required to remove the PEEK specimens. Furthermore, PEKK exhibited higher wear resistance than PEEK. Conclusion: This study evaluated custom-made removable implant-retained attachment components for overdentures, wherein the female parts were made of PEEK or PEKK. The retention stress and wear resistance were evaluated based on the type of attachment material, and the results showed that both types of attachment inserts demonstrated clinically acceptable results in terms of retention.

• 구강회복응용과학지
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• 제24권1호
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• pp.91-104
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• 2008

최근에, 의치의 유지, 안정성, 지지를 개선시키기 위해 골유착 임플란트가 사용되고 있다. 여러 연구에서 하악에 두 개의 임플란트를 식립한 후 제작된 피개의치가 환자 보철에서 기능과 만족의 유의한 증가를 나타내고 있다. stud, magnet, 그리고 bar attachment를 포함하여 다양한 attachment 시스템을 사용해 임상적으로 예상 가능하고 효과적인 것이 증명되었다. 본 증례에서 2개의 임플란트를 이용한 피개의치가 무치하악의 치료를 위한 고려의 기본이 될 수 있다는 것을 나타낸다.