• 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.

• Journal of Periodontal and Implant Science
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• 제37권3호
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• pp.647-653
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• 2007

Rapid crestal bone resorption following maxillary tooth loss is further accentuated in the posterior regions because of pneumatization and enlargement of the maxillary sinuses. A treatment rationale that allows preservation and augmentation of vertical available bone at the time of posterior maxil-lary tooth extraction may offer numerous therapeutic benefits which are more short courses of ther-apy and no needs of additional surgical augmentation. The present study comprised 3 patients who had 4 posterior maxillary teeth with no evident bone between the tooth apex and sinus floor, as estimated through preoperative radiographic analysis. Sinus floor augmentation at the time of tooth extraction was chosen for the ltreatment of these patients. After the tooth was carefully extracted, the empty alveolus was thoroughly debrided and a trephine approach was performed. Particulated autogenous bone was gently pushed beyond the empty alveolus to elevate the sinus membrane using an osteotome. The distance between bone crest and si-nus floor was radiographically estimated 4 months after the first procedure. Another procedure was then carried out to place the implants of 11 mm length without another augmentation procedure. All implant were clinically stable, with no sign of infection. The presented surgical procedure performed at the time of extraction of posterior maxillary teeth in close proximity to the sinus floor allowed placement of implants of proper length.

• 구강회복응용과학지
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• 제18권2호
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• pp.127-144
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• 2002

There is an increasing appreciation of the vital role that biomechanics play in the performance of oral implant. The aim of this article is to provide some basic principles that will allow a clinician to formulate a biomechanically valid treatment plan. However, at this point in the history of oral implantology, the clinician should realize that we do not know enough to provide absolute biomechanical rules that will guarantee success of all implants in all situations. To examine the biomechanical questions, one must begin with an analysis of the distribution of biting forcess to implants. Related topics, such as stress transfer to surrounding tissues and interrelationships between bone biology and mechanical loading are major subjects, deserving a separate discussion. Once rigid fixation, angulation, crestal bone level, contour, and gingival health are achieved, stress beyond physiologic limits is the primary cause of initial bone loss around implants. The restoring dentist has specific responsibilities to reduce overload to the bone-implant interface. These include proper diagnosis, leading to a treatment plan designed with adequate retention and form, and progressive loading to improve the amount and density of bone and further reduce the risk of stress beyond physiologic limits. The major remaining factor is the development of occlusal concept in harmony with the rest of the stomagnetic system.

• Journal of Periodontal and Implant Science
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• 제46권2호
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• pp.72-83
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• 2016

Purpose: The goal of this study was to evaluate the long-term success of horizontal alveolar crest augmentation of the retromolar region of the mandible with particulated bone, as well as factors affecting subsequent peri-implant bone loss. Methods: A total of 109 patients (68 female, 41 male) suffering from alveolar ridge deficiencies of the maxilla and mandible were included in this study. All patients were treated with particulated retromolar bone grafts from the mandible prior to the insertion of endosseous dental implants. Mesial and distal peri-implant crestal bone changes were assessed at six time points. Several parameters, including implant survival and the influence of age, gender, localisation of the implant, diameter, covering procedures, and time points of implant placement, were analysed to identify associations with bone level changes using the Mann-Whitney U-test, the Kruskal-Wallis test, and Spearman's rank-order correlation coefficient. Results: A total of 164 dental implants were placed in the maxilla (n=97) and in the mandible (n=67). The mean observation period was $105.26{\pm}21.58$ months after implantation. The overall survival rate was 97.6% after 10 years. Overall, peri-implant bone loss was highest during the first year, but decreased over time. The mean amount of bone loss after 10 years was 2.47 mm mesially and 2.50 mm distally. Bone loss was significantly influenced by implant type and primary stability. Conclusions: The use of particulated autologous retromolar bone grafts is a reliable technique for the horizontal reconstruction of local alveolar ridge deficiencies. Our results demonstrate that implants placed in augmented bone demonstrated similar bone level changes compared to implants inserted in non-augmented regions.

• 대한치과보철학회지
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• 제58권1호
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• pp.23-29
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• 2020

목적: 이번 후향적 연구의 목적은 수압을 이용하는 방식을 변형한 방식인 S-reamer 와 겔 형태의 이식재를 이용한 상악동 거상술을 시행한 임플란트의 5년 이상 추적 관찰을 함으로써 성공률과 생존률을 조사하여 이 술식에 대한 평가를 하는데 있다. 재료 및 방법: 2008년에서 2014년까지 환자들을 추적 관찰하였다. 관찰된 환자는 59명이었고 식립 임플란트는 117개였다. 남성 34명, 여성 25명이고 연령대는 다양하였다. 잔존 수직 골의 골 량은 1 - 6 mm로 다양하였다. 상악동 거상술은 막의 천공없이 상악동을 천공하는데 S-reamer를 사용하였고 막을 거상하는데 겔 형태의 이식재를 사용하여 상악동 거상술을 시행하였다. 모든 임플란트는 거상과 동시에 식립하였고 5 - 6개월 치유 기간 후 보철물을 장착하였다. 방사선 검사는 추적 검사 할 때와 식립 후 바로 찍은 방사선 검사를 비교하였다 그리고 탐침을 통하여 화농여부, 염증여부, 출혈여부 등등 임상 검사를 통하여 검진 평가 하였다. Buser의 성공 기준을 참고하였고 모든 임플란트를 성공 임플란트, 생존 임플란트, 실패 임플란트로 분류하였다. 결과: 실패하여 제거한 임플란트는 5개였고 골 소실을 동반한 급성 염증 치료를 했거나 염증을 보인 임플란트가 4개였다. 생존율은 95.7%이고 성공률은 92.3%였다. 결론: S-reamer와 겔 형태의 이식재를 이용한 상악동 거상술이 1 - 6 mm 잔존 골이 있는 상황에서 막 천공이 없이 상악동을 거상할 수 있는 성공적인 술식임을 알 수 있었다.

• 구강회복응용과학지
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• 제25권4호
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• pp.417-429
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• 2009

골유착성 임플란트가 소개된 이후로 부분 및 무치악 부위에서 사용되어 높은 성공률과 함께 예지성 있는 결과를 보여주는 치료방법으로 인정받고 있다. 그러나 국내에서 개발된 임플란트에 대해서는 임상적이고 객관적인 연구 자료가 불충분하다. 본 연구에서는 31명의 환자에게서 임플란트 경부에 미세나사를 지닌 임플란트 식립 후 평균 21개월의 기간 동안 임플란트의 생존율에 관한 조사를 시행하였고 부하가 가해지는 시점을 기준으로 12개월 간 변연골의 변화를 파노라마사진을 이용하여 측정 관찰하여 다음의 결과를 도출하였다. 총 96개의 임플란트에서 3개의 임플란트가 실패하여 96.9%의 생존율을 보였다. 50대 환자에서 85.7%로 가장 작은 생존율을 보였으며 성별 및 연령에 따른 생존율 및 변연골 흡수량에 대한 통계적 유의성은 존재하지 않았다. 상악에서는 95.7% 하악에서는 100%의 생존율을 보였다. 골이식 여부, 보철물의 종류, 매식체의 길이 및 직경에 따른 생존율의 차이는 통계적으로 유의한 차이를 보이지 않았다. 기능 부하 후 임플란트 변연골 흡수량은 단일 금관 보철물이 연결 고정 보철물에 비해 증가된 양상을 보였으나 임플란트의 직경, 길이, 골이식의 유무, 식립위치에 의해서는 통계적으로 유의한 차이를 보이지 않았다. 이 연구를 통해 경부에 미세나사를 지닌 임플란트 식립 후에 임플란트 변연골 흡수량은 비교적 적게 일어났으며 또한 안정적으로 유지되는 것이 관찰될 수 있었고 이에 따른 장기적인 추적관찰이 필요할 것으로 사료된다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제38권1호
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• pp.2-8
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• 2012

Introduction: Auto-tooth bone graft material consists of 55% inorganic hydroxyapatite (HA) and 45% organic substances. Inorganic HA possesses properties of bone in terms of the combining and dissociating of calcium and phosphate. The organic substances include bone morphogenetic protein and proteins which have osteoinduction capacity, as well as the type I collagen identical to that found in alveolar bone. Auto-tooth bone graft material is useful as it supports excellent bone regeneration capacity and minimizes the possibility of foreign body reaction,genetic diseases and disease transmission. Materials and Methods: Implant placement combined with osteoinductive regeneration,preservation of extraction socket, maxillary sinus augmentation, and ridge augmentation using block type,powder type, and block+powder type autobone graft materialwere performed for 250 patients with alveolar bone defect and who visited the Department of Oral and Maxillofacial Surgery, College of Dentistry, Dankook University from September 2009 to August 2011. Results: Clinical assessment: Among the 250 patients of auto-tooth bone graft, clinical assessment was performed for 133 cases of implant placement. The average initial stabilization of placed implants was 74 implant stability quotient (ISQ). Radiological assessment: The average loss of crestal bone in the mandible as measured 6 months on the average after the application of prosthesis load was 0.29 mm, ranging from 0 mm to 3.0 mm. Histological assessment: In the histological assessment, formation of new bone, densified lamellated bone, trabecular bones, osteoblast, and planting fixtures were investigated. Conclusion: Based on these results, we concluded that auto-tooth bone graft material should be researched further as a good bone graft material with osteoconduction and osteoinduction capacities to replace autogenous bone, which has many limitations.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제31권3호
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• pp.237-242
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• 2009

Implant-supported fixed and removable prostheses provide a proper treatment modality with reliable success. The SS $II^{(R)}$ Implants is a one-stage nonsubmerged threaded titanium implants with Resorbable Blasting Media (RBM) surface developed by Osstem company (Busan, Korea) in October of 2002. This study is to evaluate the survival rate of the SS $II^{(R)}$ Implants for 4 years using radiographic parameters and to review the retrieved implants by the cytotoxicity tests. Since September 2003, 439 SS $II^{(R)}$ implants had been used for 173 patients at Ewha Womans University Medical Center in Korea. Patients consisted of 91 females (52.6 %) and 82 males (47.4 %). The patients' mean age was $42\;{\pm}16$ years, ranging from 21 to 83 years. The follow-up period ranged from 9 to 46 months (mean F/U $24.2\;{\pm}\;10.2$ months). The results are as follows; 1. Of 439 implants, 17 implants were removed and 4-year cumulative survival rate was 96.1%. 2. 82.3% of 17 failed implants were founded during healing phase, and 94.1% of failed fixtures were removed within 5 months after implantation. 3. Crestal bone around the implants was resorbed to 1 mm in 89.0%, to 1 - 2 mm loss of the marginal bone in 8.3%, and the bone loss over 2 mm was occurred in 2.7%. 4. Microscopic examination of the retrieved implants disclosed Grade 0 cytotoxicity in 4 and Grade 1 cytotoxicity in 2 of 6 groups divided according to LOT numbers. Inhibition rate with optical density was acceptable as low as ISO standard.

• Imaging Science in Dentistry
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• 제53권1호
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• pp.1-9
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• 2023

Purpose: The aim of this study was to evaluate 3-dimensional cone-beam computed tomography (CBCT) images of alveolar bone changes in patients who underwent minimally invasive periodontal surgery-namely, the pinhole surgical technique (PST). Materials and Methods: Alveolar bone height was measured and compared on CBCT images of 254 teeth from 23 consecutive patients with Miller class I, II, or III recession who had undergone PST. No patient with active periodontal disease was selected for surgery. Two different methods were used to assess the alveolar bone changes postoperatively. In both methods, the distance between the apex of the tooth and the mid-buccal alveolar crestal bone on pre- and post-surgical CBCT studies was measured. Results: An average alveolar bone gain >0.5 mm following PST was identified using CBCT(P=0.05). None of the demographic variables, including sex, age, and time since surgery, had any significant effect on bone gain during follow-up, which ranged from 8 months to 3 years. Conclusion: PST appears to be a promising treatment modality for recession that results in stable clinical outcomes and may lead to some level of resolution on the bone level. More long-term studies must be done to evaluate the impact of this novel technique on bone remodeling and to assess sustained bone levels within a larger study population.

• 대한치과보철학회지
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• 제46권1호
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• pp.53-64
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• 2008

임플랜트 주위 변연골의 흡수는 임플랜트의 기능적 및 심미적 성공에 큰 장애가 되는 요인이다. Adell은 임플랜트에 지대주 연결 후 첫 1년간 평균적으로 1.5mm의 변연골 소실을 보이고, 이 후에는 매년 0.1mm이하의 변연골 흡수가 있었다고 하였다(Adell et al.,1981). 이러한 변연골 흡수를 막기위한 많은 노력들이 행해져 왔다. 특히 임플랜트 collar의 특징에 따라서 변연골의 흡수가 달라질 수 있다. 본 연구의 목적은 임플랜트 collar에서의 laser microtexturing(microgroove)이 변연골 흡수에 미치는 영향에 대해 알아보고자 하는 것이다. 4종류의 임플랜트 총 101개를 식립한 환자 53명에서 임플랜트 식립시부터 보철물 장착한 후 평균 6개월 후 정기 검사 시까지의 임플랜트 주위 변연골의 흡수를 측정하여 비교하였다. 생물학적 폭경을 충분히 확보한 임플랜트(ITI standard)와 생물학적 폭경이 부족한 임플랜트 (ITI esthetic plus, Silhouette IC Laser-$Lok^{TM}$, Silhouette IC)에서 변연골 흡수의 차이를 비교하였고, 임플랜트 주위 변연골의 흡수에 대한 laser를 이용한 미세나사산의(Silhouette IC Laser-$Lok^{TM}$) 영향을 알아보았다. 다음의 결과를 얻었다. 1. ITI standard와 Silhouette IC Laser-$Lok^{TM}$ 이 ITI esthetic plus 와 Silhouette IC 보다 임플랜트 주위 변연골의 흡수가 적었고 (p<0.05), ITI standard 와 Silhouette IC Laser-$Lok^{TM}$ 사이에는 변연골의 흡수가 유의차가 없었고(P>0.05), ITI esthetic plus와 Silhouette IC 사이에도 변연골의 흡수가 유의차가 없었다(P>0.05). 2. 사용된 임플랜트 전체에 대한 상하악의 비교에서는 상하악 사이에서 임플랜트 주위 변연골의 흡수는 통계학적으로 유의한 차이가 없었다(p>0.05). 3. 흡수각도에 대한 비교에서도 4종류 임플랜트 그룹 간에 통계학적으로 유의한 차이는 없었다(P>0.05). 본 연구에서 제한이 있긴 하지만, 임플랜트 디자인에서 생물학적 폭경이 부족한 경우(ITI esthetic plus, Silhouette IC)에는 생물학적 폭 경 보상을 위한 임플랜트 주위 변연골의 흡수가 있었음을 보여주고 있으나, laser를 이용한 microgroove 가 부여된 임플랜트에서는 collar의 거칠기와 laser microtexturing 등의 특징에 의해 임플랜트 주위 변연골의 흡수가 적게 일어난 것이 관찰되었다. 심미적인 요구도가 높은 전치부에서 충분한 생물학적 폭경이 확보된 임플랜트를 식립할 경우 변연골의 흡수에 따른 치은퇴축에 의해 metal collar의 노출이 우려되기에 충분한 생물학적 폭경이 부여되지 않은 임플랜트를 선정하게 되는데 이때 collar에서의 laser microtexturing은 변연골의 유지에 도움이 되었다. 이것은 조직의 단단한 부착으로 인한 안정화로 추정해 볼 수 있는데, 이에 대해서는 더 장기간의 연구와 더 많은 수의 임플랜트를 대상으로 한 연구와 조직학적인 연구도 필요할 것으로 사료된다.