• The korean journal of orthodontics
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• v.41 no.1
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• pp.25-35
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• 2011

Objective: The purpose of this study was to optimize the thread pattern of orthodontic microimplants. Methods: In search of an optimal thread for orthodontic microimplants, an objective function stability quotient (SQ) was built and solved which will help increase the stability and torsional strength of microimplants while reducing the bone damage during insertion. Selecting the AbsoAnchor SH1312-7 microimplant (Dentos Inc., Daegu, Korea) as a control, and using the thread height (h) and pitch (p) as design parameters, new thread designs with optimal combination of hand p combination were developed. Design soundness of the new threads were examined through insertion strain analyses using 3D finite element simulation, torque test, and clinical test. Results: Solving the function SQ, four new models with optimized thread designs were developed (h200p6, h225p7, h250p8, and h275p8). Finite element analysis has shown that these new designs may cause less bone damage during insertion. The torsional strength of two models h200p6 and h225p7 were significantly higher than the control. On the other hand, clinical test of models h200p6 and h250p8 had similar success rates when compared to the control. Conclusion: Overall, the new thread designs exhibited better performance than the control which indicated that the optimization methodology may be a useful tool when designing orthodontic microimplant threads.

• Journal of Dental Rehabilitation and Applied Science
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• v.27 no.3
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• pp.293-304
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• 2011

The purpose of this study was to investigate the displacement and pattern of stress distribution on periodontal ligaments of maxillary first and second molar, and on orthodontic mini-implant (OMI) surface, according to three different insertion angles to the bone surface of OMI using Dragon helix appliance, which is a newly introduced scissors-bite correcting appliance. OMI were placed between second premolar and first molar with three different insertion angles (45, 60, 90 degrees). Displacement and maximum stress distribution area (MSDA) were analyzed by finite element analysis. When the insertion angle to the alveolar bone surface was 90 degrees, maxillary first and second molar both exhibited MSDA at the palatal root apex. Maxillary first molar did not show any significant displacement, while the second molar exhibited intrusive and palatal displacement. On the OMI, as the insertion angle decreased, the MSDA shifted towards the tip, and the amount of displacement had increased. When the OMI was inserted at a 90 degree angle, anchor loss was minimized and scissors-bite correcting effect was maximized.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.3
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• pp.167-174
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• 2018

Purpose: The purpose of present study was to retrospectively analyze the survival rate of implant placed after alveolar ridge preservation by initial stability and radiographic measurements. Materials and Methods: In total, 19 patients who received 21 sandblasted, large-grit, acid-etched (SLA) implants were enrolled in this retrospective study. Implants placed after alveolar ridge preservation technique (ARP) 2 - 3 months healing period, Periotest value (PTV) measured at implant placement and before placed prosthodontics. Marginal bone level (MBL) was measured at implant placement and final recall check. Results: Overall survival rate of implant was 100%. Mean PTV at implant placement was $-0.06{\pm}8.33$ and mean PTV before placed prosthodontics was $-5.75{\pm}1.7$. The range of MBL change was from -0.55 mm to 1.6 mm (Mean: $0.19{\pm}0.58mm$). Conclusion: The findings of present study suggest that the implant paced after alveolar ridge preservation appear high survival rates and stable MBL.

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.4
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• pp.391-401
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• 2009

The successful outcome of dental implants is mainly the result of intial implant stability following placement. The aim of this study was to investigate the effect of a self-tapping blades and implant design on initial stability of two tapered implant systems in poor bone quality. The two different implant systems included one with self-tapping blades and one without self-tapping blades. D4 bone model using Solid Rigid Polyurethane Form was used to simulate poor bone densities. The insertion torque during implant placement was recorded. Resonance frequency Analysis (RFA), measured as the implant stability quotient (ISQ), was assessed immediately after insertion. Finally, the implant-bone specimen was transferred to an Universal Testing Machine to measure the axial pull-out force. Insertion torque values and maximum pull-out torque value of the non self-tapping implants were significantly higher than those in the self-tapping group (P = 0.008). No statistically differences were noted between the two implant designs in RFA. Within the each implant system, no correlation among insertion torque, maximum pull-out torque and RFA value could be determined. Higher insertion torque of the non-self-tapping implants appeared to confirm higher clinical initial stability. In conclusion, implants without self-tapping blades have higher initial stability than implants with self-tapping blades in poor bone quality.

• The korean journal of orthodontics
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• v.36 no.3 s.116
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• pp.171-177
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• 2006

The purpose of this study was to evaluate the light microscopic features and the maximum insertional and removal torque value of microimplants, made from titanium grade 2 or 4, in the tibia of 6 rabbits. First, the maximum torque values of microimplants at implantation were measured. After 2, 8, and 12 weeks of healing time, the microimplant-containing segments of tibia of 2 rabbits were removed and the maximum removal torque of each microimplant were measured. Comparisons of histologic examination and insertional and removal torque values were carried out for the two groups of microimplants. Removal torque values were significantly increased in both groups after 8 and 12 weeks as compared to 2 weeks after implantation. Other values measured did not show any statistically significant differences and there were no histological differences between grade 2 and 4 titanium. Based on these results, this study showed that there were no significant differences between grade 2 and 4 titanium. It seems better to use grade 4 titanium for making microimplants because grade 4 titanium is mechanically harder than grade 2 titanium and has similar retention.

• The korean journal of orthodontics
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• v.39 no.3
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• pp.146-158
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• 2009

Objective: The purpose of this study was to reveal the position of the incisive foramen in relation to the incisive papilla and cusp tips. Methods: Plaster models and CT images of 25 adult orthodontic patients were used to measure the width of the incisive canal and positions of the anterior and posterior borders of the incisive foramen in relation to the incisive papilla. Results: The palatal surface distance from the interdental papilla between the maxillary central incisors to the posterior border of the incisive foramen along the palatal surface was 1.7 fold of the distance from the interdental papilla between the central incisors to the posterior border of the incisive papilla. The distance between the posterior border of the incisive papilla and posterior border of the incisive foramen along the palatal surface was 6.15 ${\pm}$ 1.75 mm. The anteroposterior position of the posterior border of the incisive foramen was slightly anterior to the lingual cusp tips of the maxillary 1st premolars. The width of the incisive foramen was 4.03 ${\pm}$ 0.64 mm, therefore it is recommended to position the mini-implant more than 3 mm laterally when placing a mini-implant lateral to the incisive foramen, from the center. Conclusions: These results can be used as a reference in presuming the position of the incisive foramen when placing mini-implant in the anterior palate area.

• Journal of Periodontal and Implant Science
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• v.35 no.3
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• pp.609-621
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• 2005

1. 목적 Osteotome 상악동거상술(Bone Added Odteotome Sinus Floor Elevation ; 이하 BAOSFE) 과 동시에 식립한 임프란트($Br{\aa}nemark$, ITI)의 예상 생존율에 대해 현재까지 정확히 알려진 바는 없었으며, $Br{\aa}nemark$ Ti-Unite 과 ITI SLA 임프란트의 표면에 대한 비교 연구 또한없었다. 이번 연구는 BAOSFE 술식과 동시에 식립한 $Br{\aa}nemark$ Ti-Unite 과 ITI SLA 임프란트의 임상 결과를 비교, 평가하고 초기 치유기간 동안의 이식골 높이의 변화를 방사선학적으로 관찰하여 두 가지 임프란트 시스템을 비교해 보고자 한다. 2. 방법 위축된 상악 구치부를 갖는 22명의 환자를 대상으로, BAOSFE술식과동시에 $Br{\aa}nemark$ Ti-Unite(11명, 13 임프란트)임프란트와 ITI SLA(11명, 18 임프란트)임프란트를 식립하였다. 수술 전, 임프란트 식립 직후, 술후 6개월의 파노라마 방사선 사진을 촬영하여 비교 및 평가에 사용하였다. 각 임프란트 시스템의 생존율을 측정하고, 술전 상악동저 높이와 식립된 임프란트 길이를 참고하여 이식골 높이의 방사선학적 변화를 평가하였다. 3. 결과 평균12개월의 추적기간 결과, $Br{\aa}nemark$ Ti-Unite 임프란트의 생존율은 100%(13/13 임프란트)이었으며, ITI SLA 임프란트의 생존율은 94.4%(17/18 임프란트)이었다. 초기 치유 기간인 6개월 동안 평균 이식골 높이의 감소는 $Br{\aa}nemark$ Ti-Unite 임프란트에서 0.67mm(10.73%), ITI SLA 임프란트에서는 0.55mm(8.18%)로 나타났다. 두 가지 임프란트 시스템 간의 유의성 있는 차이는 보이지 않았다. 4. 고찰 BAOSFE 술식과 동시식립한 $Br{\aa}nemark$ Ti-Unite 과 ITl SLA 임프란트는 위축된 상악 구치부를 갖는 환자에서 효과적인 치료방법이 될 수 있으며, 임프란트 표면에 따른 이식골의 치유 반응은 두 가지 임프란트 시스템에서 유사한 양상으로 일어남을 알 수 있었다.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.2
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• pp.193-200
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• 2008

Statement of problem: There have been a few studies about unsplinted implant retainted maxillary overdenture. Purpose: The purpose of this study was to examine the effect of different position of implant for 2 implants-retained maxillary overdenture. Materials and methods: Three-dimensional finite element models were used to reproduce an edentulous human maxilla with an implant-retained overdenture. Two implants in the canine tooth positions on both side and in the second premolar tooth positions on both side models were examined. Axial loads of 100 N were applied to the occlusal surface at the right first molar tooth positions. Maximum stress at the implant-bone interface and stress at the cortical bone surface just under the loading point were observed. Results and conclusion: Within the limits of this study, maximum stresses were concentrated around implant of canine position at loading side. The second premolar area was thought to be more favorable to distribution of stress on mucosa, alveolar bone and implants than canine area for maxillary overdenture.

• The Journal of Korean Academy of Prosthodontics
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• v.55 no.3
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• pp.286-291
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• 2017

Maintaining the blood supply of the interdental alveolar bone is crucial for preserving the interdental papilla. Rebuilding the interimplant papilla between adjacent implants is more difficult than rebuilding the interdental papilla between the natural tooth and implant. Therefore, preserving the interimplant tissue is necessary when adjacent implants are closely placed. In this case report, three effective methods for maintaining the surrounding tissue, namely strategic serial extraction, immediate implantation, and provisionalization of adjacent maxillary central incisors, were performed. The marginal gingiva and interimplant papilla were well maintained for 24 months.

• The Journal of the Korean dental association
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• v.53 no.5
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• pp.326-347
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• 2015

목적: 노인 환자에서 식립된 임플란트의 생존율을 조사하고 다양한 요인에 따라 생존율에 미치는 영향을 후향적으로 평가하고자 하였다. 재료 및 방법: 2001년 1월부터 2007년 12월까지 조선대학교 치과병원 치주과에 내원한 65세 이상 노인 환자 56명에게 식립된 138개의 임플란트를 대상으로 하였다.(남자 38명, 여자 18명, 평균 연령$69.38{\pm}3.91$세) 임플란트 생존율은 환자 성별 및 연령, 전신질환 유무, 치아 상실 원인, 식립 위치, 임플란트 직경 및 길이, 골질, 골이식 여부, 상부 보철물 유형에 따라 조사되었다. Kaplan-Meier survival analysis을 통해 각 요인에 따른 누적 생존율을 조사하였고, chi-square test를 통해 누적 생존율과 각각의 요인 간의 통계학적 유의성을 평가하였다. 결과: 보철물 시적 후 5 ~ 140개월 간 추적 관찰을 시행하였다. 65세 이상 노인 환자 56명에게 식립된 총 138개의 임플란트 중 추적 관찰 기간 동안 5개의 임플란트가 실패하였다. 그 중 63개의 임플란트는 환자가 정기적인 내원 약속에 응하지 않아 도중에 조사대상에서 제외되었으며, 결과적으로 5년간 누적 생존율은 94.9%였다. 임플란트 생존율에 영향을 미치는 다양한 요인 중 골질 (P=0.037) 및 상부 보철물 유형 (P=0.015) 간에 누적 생존율이 통계적으로 유의한 차이가 있었다. 그외 연령, 성별, 전신질환 유무, 치아상실 원인, 식립 위치, 임플란트 직경 및 길이, 골이식 유무 관련 요인과 누적 생존율 사이에는 통계적으로 유의한 차이가 없었다. 결론: 여러 한계가 있었지만 노인 환자의 무치악 부위에 있어 임플란트는 장기간에 걸쳐 예지성 있고 받아들여질 만한 치료이면서 적은 합병증과 실패율을 가진다.