• 대한심미치과학회지
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• 제29권2호
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• pp.66-74
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• 2020

환자를 위한 보철물들은 사실 하나도 빠짐없이 'custom'한 보철물입니다. 임플란트보철물 제작시 기성 abutment를 사용한다고 하더라도 최종결과물은 여전히특정 환자만을 위한 'custom'보철물입니다. 환자에게 정말 잘 맞춤(custom)된 보철물을 제작하는데 있어 치과의사와 치과기공사간의 소통과 협업이중요하다는 것은 누구나 알고 있는 사실입니다. 하지만 이러한소통과 협업이 제대로 이루어지려면 먼저 양쪽이 치료방법 및 결과 등에 대한 공통된 임상의 '상식'을 공유하고 있어야 합니다. 아이러니하게도 치과의사와 치과기공사간에 서로 다른 '상식'을 갖고 있음을 확인하게 되는 경우가 의외로 많은 것 같습니다. 임플란트 보철물의 emergence profile은 치주적 건강도나 심미성에 있어 아주 중요한 연결고리임에도 불구하고, 이에 관하여 문헌상에서 명확한 가이드라인이 제시된 바가 없습니다. 자연치아와 임플란트간의 태생적 차이에서 오는 문제들을 인지하고 이를 해결하기 위한 방법들이 치과의사와 치과기공사 모두에게 '상식'으로 공유될 수 있을 때 비로소 환자에게 제대로 맞춤된 보철물이 제작될 수 있습니다.

• 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.

• 대한치과보철학회지
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• 제31권1호
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• pp.129-150
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• 1993

Since the restoration or masticatory function is the most important aim of implants, it should be substituted for the role of natural teeth and deliver the stress to the bone under the continous load during function. In natural teeth, stress distribution can be obtained through enamel, dentin and cementum and the elasticity of the periodontal ligament play a role of buffering action. In contrast, implant prosthesis has a very unique characteristics that it delvers the load directly to bone through the implant and superstructure. This fact arise the needs to evaluate the stress distribution of the implant in the mechnical aspects, which has a similar role of natural teeth but different pathway of stress. With 3 kinds of implant in prevalent use, 2 types of experimental PEA implant models were made, axisymmetric and 2-dimensional type. In axisymmetric model, the stiffness of the part including the prosthesis and implant which extrude out of bony surface could be calculated with displacement of the superstructure un er 100N vertical load and then damping effects could be determined through this stiffness. In axisymmetric FEA model, load to the bone could be deduced by evaluation the stress distribution of the designed surface under the 100N vertical force and in 2-dimensional model, 100N eccentric vertical load and 20N horizontal loda. The result are as follows. 1. In every implant, stress to the bone tends to be concenturated on the cortical bone. 2. Though the stress of the cancellous bone is larger at the apex of implants, it is less compared with cortical bone. 3. Under 20N horizontal load, stress of the left and right sides of implant shows a symmetrical pattern. But under 100N eccentric vertical load, loaded side shows much larger stress value. 4. In the 1mm interface, stress distribution among implants tend to have a similar pattern. But under 20N horizontal load apposite side of being loaded shows less stress in IMZ. 5. In the case of screw type implant, stress tends to vary along with screw shape. 6. According to the result determined with microstrain, cancellous bone id generally under the condition of overload, while cortical bone is usually within the limitation of physiologic load. 7. In the Branemark implant, maximum stress to the cortical bone is larger than any other implant except for the condition of 20N horizontal force and 0.05mm interface. 8. Damping effects of implants is maximum in IMZ.

• 대한치과보철학회지
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• 제56권4호
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• pp.323-329
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• 2018

후방 무치악 부위를 수복하는데 있어서 선택할 수 있는 전통적인 치료방법으로는 가철성 국소의치와 임플란트 고정성 보철물이 있다. 최근, 환자의 전신 건강과 심미적 요구사항, 치료 비용, 잔존 치조골 상태 등을 고려하여, 두가지 치료가 결합된 임플란트 융합 국소의치(implant assisted RPD)개념이 이용되고 있다. 임플란트 융합 국소의치는 치조골 결손부가 큰 경우나, 생역학적으로 불리한 경우에 전통적인 가철성 국소의치보다 유지력과 안정성을 증진시킬 수 있으며 심미적이라는 장점이 있다. 또한 치조골 양이 상대적으로 많은 부위에 전략적으로 임플란트를 식립하여 전통적인 국소의치 디자인의 한계를 개선할 수 있을 뿐 아니라, 다수의 임플란트 식립을 통한 고정성 보철물에 비해 환자의 수술 부담을 줄여줄 수 있으며, 비용 절감 효과도 기대할 수 있다. 본 증례의 환자는 하악 양측 소구치부에 단일 임플란트를 식립하여, 임플란트 고정성 보철물을 지대치로 하는 양측성 후방연장 국소의치를 제작하여 치료를 진행하였다. 최종 보철물 장착 후 환자는 저작 기능 및 심미에 대해 만족도를 나타내었다. 이후 1년 이상 주기적인 관찰을 통해 예후를 관찰 중이다. 하악 부분 무치악 환자에서 임플란트를 이용한 가철성 국소의치 수복을 통해 증진된 지지와 안정을 얻었기에 이를 보고하는 바이다.

• Journal of Periodontal and Implant Science
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• 제42권6호
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• pp.231-236
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• 2012

Purpose: The aim of this study was to evaluate the influence of the crown-to-implant (C/I) ratio on the change in marginal bone level around the implant and to determine the site-related factors influencing the relationship between the C/I ratio and periimplant marginal bone loss. Methods: A total of 259 implants from 175 patients were evaluated at a mean follow-up of five years. Implants were divided into two groups according to their C/I ratios: ${\leq}$ 1, and >1. Site-related factors having an influence on the relationship between C/I ratio and periimplant marginal bone loss were analyzed according to the implant location, implant diameter, implant manufacturer, prosthesis type, and guided bone regeneration (GBR) procedure. Results: It was found that 1) implants with a C/I ratio below 1 exhibited greater periimplant marginal bone loss than implants with a C/I ratio more than 1, 2) site-related factors had an effect on periimplant marginal bone loss, except for the implant system used, 3) the C/I ratio was the factor having more dominant influence on periimplant marginal bone loss, compared with implant diameter, prosthesis type, implant location, and GBR procedure, 4) implants with a C/I ratio below 1 showed greater periimplant marginal bone loss than implants with a C/I ratio greater than 1 in the maxilla, but not in the mandible, 5) and periimplant marginal bone loss was more affected by the implant system than the C/I ratio. Conclusions: Within the limitations of this study, implants with a higher C/I ratio exhibited less marginal bone loss than implants with a lower C/I ratio in the posterior regions. The C/I ratio was a more dominant factor affecting periimplant marginal bone loss in the maxilla than the mandible. Meanwhile, the implant system was a more dominant factor influencing periimplant marginal bone loss than the C/I ratio.

• 대한치과보철학회지
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• 제59권4호
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• pp.469-477
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• 2021

상악 전치부 임플란트의 성공적인 수복을 위해서는 pink esthetics와 white esthetics가 모두 충족되어야 한다. Pink esthetics 부분의 경우 적절한 임시보철물의 역할이 중요하고, white esthetics 부분의 경우에는 최종 보철물의 색상과 형태가 중요하다. 다층 지르코니아는 기존의 단일구조 지르코니아에 비해 절단 부위의 투명도가 높기 때문에 추가적인 도재 축성 없이 자연스러운 보철물 제작이 가능하다. 따라서 본 증례에서는 상악 전치를 상실한 환자에서 적절한 임시보철물을 통해 기능과 심미성을 충분히 회복한 후 다층 지르코니아를 통해 white esthetics를 달성하였다.

• The Journal of Advanced Prosthodontics
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• 제10권6호
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• pp.430-439
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• 2018

The treatment of craniofacial anomalies has been challenging as a result of technological shortcomings that could not provide a consistent protocol to perfectly restore patient-specific anatomy. In the past, wax-up and impression-based maneuvers were implemented to achieve this clinical end. However, with the advent of computer-aided design and computer-aided manufacturing (CAD/CAM) technology, a rapid and cost-effective workflow in prosthetic rehabilitation has taken the place of the outdated procedures. Because the use of implants is so profound in different facets of restorative dentistry, their placement for craniofacial prosthesis retention has also been widely popular and advantageous in a variety of clinical settings. This review aims to effectively describe the well-rounded and interdisciplinary practice of craniofacial prosthesis fabrication and retention by outlining fabrication, osseointegrated implant placement for prosthesis retention, a myriad of clinical examples in the craniofacial complex, and a glimpse of the future of bioengineering principles to restore bioactivity and physiology to the previously defected tissue.

• 구강회복응용과학지
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• 제20권1호
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• pp.57-70
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• 2004

The significance of occlusion has regained its popularity in dentistry with the introduction of implant therapy. Literature has reported that the clinical success and longevity of dental implants can be achieved by biomechanically controlled occlusion. Occlusal overload is known to be one of the main causes for implant failure. Evidences have suggested that occlusal overload contribute to early implant bone loss as well as deosseointegration of successfully integrated implants. Unlike natural teeth, osseointegrated implants are ankylosed to surrounding bone without the periodontal ligament (PDL) which provides mechanoreceptors as well as shock-absorbing function. Moreover, the crestal bone around dental implants may act as a fulcrum point for lever action when a force (bending moment) is applied, indicating that implants/implant prosthesis could be more susceptible to crestal bone loss by applying force. Hence, it is essential for clinicians to understand inherent differences between teeth and implants and how force, either normal or excessive force, may influence on implants under occlusal loading. The purposes of this paper are to review the importance of implant occlusion, to establish the optimum implant occlusion with biomechanical rationale, to provide clinical guidelines of implant occlusion and to discuss how to manage complications related to implant occlusion.

• 대한치과의사협회지
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• 제58권8호
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• pp.496-504
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• 2020

The osseointegrated implants react biomechanically in a different pattern to occlusal force, due to lack of the periodontal ligament unlike the natural teeth. The implants show markedly less movement and limited tactile sensitivity compared with the natural teeth. The implant occlusion concept aims to avoid overloading on the implants and to direct occlusal loads along the longitudinal axis of the implants, in order to compensate for the different biomechanics of the implants. Although many guidelines and theories on implant occlusion have been proposed, few have provided strong supportive evidence. Moreover, the outcome of treatment often quite successful in spite of different concepts of occlusion and there is an increasing tendency to doubt about the strict theoretical implant-specific occlusion concept. The purpose of this article is to review the previous reports about the concept of implant occlusion and discuss clinical occlusal considerations in implant rehabilitations.

• 대한치과의사협회지
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• 제56권5호
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• pp.263-276
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• 2018

Long-term survival and prognosis of narrow-diameter implants have been reported to be adequate to consider them a safe method for treating a deficient alveolar ridge. The objective of this study was to perform case report of narrow-diameter implants with a trapezoid-shape in anterior teeth alveolar bone. A 50-year-old male patient presented with discomfort due to mobility of all of the maxillary teeth and mandibular incisors. Due to destruction of alveolar bone, four anterior mandibular teeth were extracted. Soft tissue healing was allowed for approximately 3 months after the extraction, and a new design of implant placement was planned for the mandibular incisor area, followed by clinical and radiological evaluation. Implant placement was determined using an R2GATE surgical stent. The stability of the implants was assessed by ISQ measurements at the first and second implant surgery and after prosthetic placement. At 1 and 3 months and 1 year after implantation of the prosthesis, clinical and radiological examinations were performed. Another 50-year-old male patient presented with discomfort due to mobility of the mandibular central incisors. For the same reason as in the first patient, implant placement was carried out in the same way after extraction. ISQ measurements and clinical and radiological examinations were performed as in the previous case. In these two clinical cases, 12 months of follow-up revealed that the implant remained stable without inflammation or additional bone loss, and there was no discomfort to the patient. In conclusion, computer-guided implant surgery was used to place an implant in an optimal position considering the upper prosthesis. A new design of a narrow-diameter implant with a trapezoid-shape into anterior mandibular alveolar bone is a less invasive treatment method and is based on the contour of the deficient alveolar ridge. Through all of these procedures, we were able to reduce the number of traumas during surgery, reduce the operation time and total treatment period, and provide patients with more comfortable treatment.