• Journal of Oral Medicine and Pain
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• 제20권2호
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• pp.317-325
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• 1995

This study was performed to investigate the mean life expectancy of dental prosthetic restorations. The author has examined 352 dental prosthesis clinically and radiologically, and decided the success(survival) and failure(mortality) of the dental prosthesis. The dental prosthesis which had been treated in the Seoul National University Dental Hospital, two private clinics in Seoul, one university dental hospital, and two private clinics in local province were included in this study. The survival analysis using product limit estimator was used and the mean life expectancy of each type of dental prosthesis was calculated. The results were as follows : 1. The life expectancies were 10.5 years in gold crown and bridge, 8.5 years in porcelain fused to metal crown and bridge, 8.3 years in nonprecious metal crown and bridge, 8.1 years in removal partial denture, and 7.7 years in full denture. 2. The causes of mortality were in the order of dental caries(24.6%), fracture of dental prosthesis(19.2%), periodontal problems(18.6%), chronic chewing difficulty and dysfunction due to dental prosthesis(15.0%), excessive exposure of abutments due to the marginal defect of dental prosthesis(14.4%), abnormal occlusion due to severe attrition of artificial teeth in dentures(3.0%), periapical problems(2.4%), perforation of dental prosthesis(1.8%), and loose contacts with neighboring tooth(1.2%). 3. Among survival cases, 66.5% showed normal chewing ability and 31.9% showed partial chewing ability. However, 1.6% of them complained loss of chewing ability. 4. Among failure cases, 6.6% showed normal chewing ability and 38.9% showed partial chewing ability. However, 54.5% of them complained loss of chewing ability.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제47권2호
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• pp.149-150
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• 2021

Bruxism is defined as a parafunctional activity during sleep or while awake that includes locking and grinding of teeth and clenching. It generates excessive occlusal force that may lead to implant failure. Therefore, diagnosis of bruxism and providing specific protocols such as occlusal splint and/or injection of botulinum toxin before implant installation are important to prevent increases the risk of implant failure in bruxism patients.

• 대한심미치과학회지
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• 제27권2호
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• pp.105-115
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• 2018

치과기공사는 구강 모델에 기초하여 보철물을 제작하기 때문에 안모와의 부조화가 되는 경우가 있다. 안모와의 부조화에 기인한 보철물의 실패를 예방하기 위해서는 진료실과 기공소 간의 소통에 기반한 모델 진단, 안면 및 구강사진을 참고하여 제작해야한다. 그리고 치과기공사는 색과 형태에 대한 이해를 위해 자연치 관찰이 필요하며 Kuraray Noritake의 internal stain 및 투명감을 부여해 주는 powder를 이용하면 자연감 있는 보철물을 제작하데 용이하다.

• 대한치과보철학회지
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• 제54권4호
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• pp.423-430
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• 2016

임플란트 보철물은 나사 유지형 보철물과 시멘트 유지형 보철물로 나눌 수 있다. 각 방법은 장점과 함께 임플란트를 유지 관리하는데 불리한 단점을 가지고 있다. 이러한 단점을 극복하기 위해 개선된 설측 고정 나사 시스템(T-screw system)이 개발되었다. T-screw system은 설측 방향의 나사를 이용하여 임플란트 보철물을 유지하는 방법으로, 보철물의 탈부착이 쉽고, 수동적 적합이 가능하며, 심미적이고 기능적인 교합면을 형성할 수 있다는 장점이 있다. 기존의 수평 나사를 이용한 보철은 기공 과정이 어려워 다수 유닛의 보철물의 경우 제작이 쉽지 않았고, 완전 도재를 이용한 보철물에서는 사용할 수 없다는 한계를 가지고 있었다. 본 증례에서 T-screw system을 이용하여 임플란트 보철물을 제작함으로써 유지 관리가 용이하고 심미적, 기능적으로 우수한 결과를 얻었다. 또한 다수 유닛의 임플란트 보철 및 완전 도재를 이용한 임플란트 보철에서 T-screw system을 이용하는 방법을 보고하고자 한다.

• The Journal of Advanced Prosthodontics
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• 제12권2호
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• pp.67-74
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• 2020

PURPOSE. This study evaluated the influence of prosthesis weight and number of implants on the bone tissue microstrain. MATERIALS AND METHODS. Fifteen (15) fixed full-arch implant-supported prosthesis designs were created using a modeling software with different numbers of implants (4, 6, or 8) and prosthesis weights (10, 15, 20, 40, or 60 g). Each solid was imported to the computer aided engineering software and tetrahedral elements formed the mesh. The material properties were assigned to each solid with isotropic and homogeneous behavior. The friction coefficient was set as 0.3 between all the metallic interfaces, 0.65 for the cortical bone-implant interface, and 0.77 for the cancellous bone-implant interface. The standard earth gravity was defined along the Z-axis and the bone was fixed. The resulting equivalent strain was assumed as failure criteria. RESULTS. The prosthesis weight was related to the bone strain. The more implants installed, the less the amount of strain generated in the bone. The most critical situation was the use of a 60 g prosthesis supported by 4 implants with the largest calculated magnitude of 39.9 mm/mm, thereby suggesting that there was no group able to induce bone remodeling simply due to the prosthesis weight. CONCLUSION. Heavier prostheses under the effect of gravity force are related to more strain being generated around the implants. Installing more implants to support the prosthesis enables attenuating the effects observed in the bone. The simulated prostheses were not able to generate harmful values of peri-implant bone strain.

• 구강회복응용과학지
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• 제29권3호
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• pp.290-298
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• 2013

치아와 치주 조직 및 이를 이용하는 보철물을 포함한 구강 내 환경을 실시간으로 감시할 수 있다면, 보철 치료의 성공과 실패를 예측하고 임상적 합병증을 방지할 수 있을 것이다. 본 논문에서는 미세전자기계시스템(MEMS) 및 생체감지(Biosensing)와 관련된 문헌 고찰을 통해 구강 내 특정 인자들을 모니터링 하는 지능형 보철물의 개념을 소개하고 그 구현 가능성을 살펴보고자 하였다.

• 대한심미치과학회지
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• 제23권2호
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• pp.77-79
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• 2014

There are several factors affected fractures of full contour zirconia (FCZ) dental prosthesis in laboratory process. First, residual moisture can cause zirconia cracks. Complete dry is requisite before zirconia sintering to prevent zirconia cracks. Second, slow cooling rate is essential to prevent cracks during zirconia sintering process. Cracks in bridge pontic area, thick dental implant prosthesis can be prevented by slow cooling rate such as 3 degree Celsius per minute during zirconia sintering. Third, slow heating rate and slow cooling rate during staining and glazing procedure is necessary to inhibit thermal shock of sintered dental zirconia. Lower preheat temperature of porcelain furnace is recommended. Finally, using diamond disc to open embrasure can lead cracks.

• 대한치과의사협회지
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• 제47권4호
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• pp.184-190
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• 2009

OBJECTIVE The purpose of clinical study was to evaluate the survival of dental implants used in restoring patients with implant supported removable partial dentures (ISRPDs) of different configurations. MATERIALS AND METHODS The sample consisted of 20 consecutively treated partially edentulous patients, who, between 2003 and 2008, had a total of 84implants placed in different arch sites and who were treated with ISRPDs. The mean age was 57 years. Mean follow up time from delivery of ISRPDs was 3 years 2 months (range, 1 to 6 years). Osseointegration failure, postoperative complication of dental prosthesis, and the success rate of ISRPDs were retrospectively evaluated using clinical and radiographic examination. RESULT The overall implant survival rate was 100%. During follow up, the one clasp of removable partial denture was broken in 1 year11 months after prosthesis delivery. All patients were satisfied with their prosthesis. CONCLUSIONS Implant supported removable partial dentures could serve as favorable prognosis. Careful patient selection, with an appropriate maintenance and recall system, is recommended to obtain satisfactory results.

• Journal of Periodontal and Implant Science
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• 제52권3호
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• pp.230-241
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• 2022

Purpose: The purpose of this study was to evaluate failed implants and reimplantation survival and to identify the relative risk factors for implant re-failure. Methods: Ninety-one dental implants were extracted between 2006 and 2020 at the National Health Insurance Service Ilsan Hospital, including 56 implants in the maxilla and 35 implants in the mandible that were removed from 77 patients. Patient information (e.g., age, sex, and systemic diseases) and surgical information (e.g., the date of surgery and location of the implants and bone grafts) were recorded. If an implant prosthesis was used, prosthesis information was also recorded. Results: In total, 91 first-time failed dental implants in 77 patients were analyzed. Of them, 69 implants in 61 patients received reimplantation after failure. Sixteen patients (22 implants) refused reimplantation or received reimplantation at a different site. Eight of the 69 reimplants failed again. The 1-year survival rate of the 69 reimplants was 89.4%. Age at reimplantation and smoking significantly increased the risk of reimplantation failure. However, a history of taking anti-thrombotic agents showed a statistically significant negative association with reimplantation failure. Of the failed implants, 66% showed early failure and 34% showed late failure of the initial implantation. All 8 re-failed implants showed early failure. Only 3 of these 8 failed reimplants were re-tried and the second reimplants all survived. Conclusions: The total survival rate of implants, which included reimplants and second reimplants was 99.2%, although the survival rate of the initial implantations was 96.3%. Previous failure did not affect the success of the next trial. Reimplantation failure was more strongly affected by patient factors than by implant factors. Therefore, each patient's specific factors need to be meticulously controlled to achieve successful reimplantation.

• 대한치과의사협회지
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• 제47권9호
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• pp.585-595
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• 2009

Purpose : The aim of this study was to compare surgical complications between simple implant placement and implant placement combined with complicated surgical procedures. We also evaluated prosthetic complications according to the specific types of prosthesis. Material and Method : A retrospective analysis of dental chart of patients who was performed implant therapy during the period from June 2003 to December 2005 was carried out. This study was performed on 408 patients (208 male, 200 female). In addition, 1671 implants were performed. Based on their medical record and radiographs, the authors evaluated surgical and prosthetic complications, surgical procedures accompanied at the time of implant, risk factors of implant failure etc. Result : Surgical complications were developed on 358 implants(21.4% on total placed implants) and wound dehiscence was most prevalent complication. On maxillary posterior area, surgical complications developed more frequently on implants with major surgery and showed a significant difference. And complication rate of implants accompanied with GBR was higher than that of simple implants placement and also showed significant difference. The implant supported prosthesis showed no statistical difference in the occurrence of complications according to the types of prosthesis, and food retention was the most common post-prosthetic complication. Also we speculated that length and width of implant showed significant correlation to the failure of implant primary osseointegration. Conclusion : Based on the result, clinician should provide more careful maintenance for patients with implant placement accompanied by complicated surgical procedure. And periodic maintenance for the patient is requested for long-term survival of implant therapy.