• The Journal of Korean Academy of Prosthodontics
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• 제37권4호
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• pp.399-415
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• 1999

임플랜트 보철 환자의 하악 운동에 관한 연구를 위해 완전 고정성 보철 치료를 한 8명의 환자와 상하악 총의치를 장착한 8명의 환자, 그리고 5명의 자연치아 피검자를 대상으로 Sirognathograph(Siemens, Benshiem, Germany)와 BioPAK program(BioResearch, Milwaukee, U.S.A.)으로 한계운동과 당근시편에 대한 편측 저작운동에 대한 검사를 시행하였다. 편측 저작 운동은 전두면에서의 저작운동의 높이와 폭, 전두면에서의 저작각도, 시상면에서의 절치기준점의 최대 이동거리, 시상면에서의 저작운동의 전후방 이동거리, 최대개구속도, 최대폐구속도의 기준점으로 각 저작주기의 성적을 평균처리 하여 다음과 같은 결론을 얻었다. 1. 전두면에서의 저작운동의 높이는 자연치, 총의치, 임플랜트 군간에 유의성있는 차이가 없었다(p>0.05). 2. 전두면에서의 저작운동의 폭은 임플랜트 군이 자연치, 총의치 군에 비해 유의성있게 작은 수치를 보였다(p<0.05). 3. 전두면에서의 저작각도 분석시 임플랜트 군과 자연치 군, 임플랜트 군과 총의치 군간에 유의성있는 차이가 없었다(p>0.05). 4. 시상면에서의 절치기준점의 최대 이동거리 분석시 임플랜트 군과 자연치 군, 임플랜트 군과 총의치군간에 유의성 있는 차이가 없었다(p>0.05). 5. 시상면에서의 전후방이동거리는 자연치 군이 임플랜트 군, 총의치 군에 비해 유의성 있게 크게 나타났다(p<0.05). 6. 최대개구속도는 자연치 군이 총의치 군과 임플랜트 군에 비해 유의성 있게 작은 수치를 보였다(p<0.05). 7. 최대폐구속도는 각 군간에 유의성 있는 차이가 없었다(p>0.05). 8. 저작운동은 개인간의 차이가 커서 명확한 결론을 유추하기가 어려웠다.

• The Journal of Korean Academy of Prosthodontics
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• 제46권2호
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• pp.157-168
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• 2008

Statement of problem: Over the past two decades, implant supported fixed prosthesis have been widely used. However, there are few studies conducted systematically and intensively on the splinting effect of implant systems in mandible. Purpose: The purpose of this study was to investigate the changes in stress distributions in the mandibular implants with splinting or non-splinting crowns by performing finite element analysis. Materials and methods: Cortical and cancellous bone were modeled as homogeneous, transversely isotropic, linearly elastic. Perfect bonding was assumed at all interfaces. Implant models were classified as follows. Group 1: $Br{{\aa}}nemark$ length 8.5mm 13mm splinting type Group 2: $Br{{\aa}}nemark$ length 8.5mm 13mm Non-splinting type Group 3: ITI length 8.5mm 13mm splinting type Group 4: ITI length 8.5mm 13mm Non-splinting type An load of 100N was applied vertically and horizontally. Stress levels were calculated using von Mises stresses values. Results: 1. The stress distribution and maximum von Mises stress of two-length implants (8.5mm, 13mm) was similar. 2. The stress of vertical load concentrated on mesial side of implant while the stress of horizontal load was distributed on both side of implant. 3. Stress of internal connection type was spreading through abutment screw but the stress of external connection type was concentrated on cortical bone level. 4. Degree of stress reduction was higher in the external connection type than in the internal connection type.

• 대한치과보철학회:학술대회논문집
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• 대한치과보철학회 1998년도 추계학술대회
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• pp.41-41
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• 1998

• The korean journal of orthodontics
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• 제40권3호
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• pp.167-175
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• 2010

Objective: The aim of this study was to validate the Periotest values for the prediction of orthodontic mini-implants' stability. Methods: Sixty orthodontic mini-implants (7.0 mm $\times$ $\emptyset1.45$ mm; ACR, Biomaterials Korea, Seoul, Korea) were inserted into the buccal alveolar bone of 5 twelve month-old beagle dogs. Insertion torque (IT) and Periotest values (PTV) were measured at the installation procedure, and removal torque (RT) and PTV were recorded after 12 weeks of orthodontic loading. To correlate PTV with variables, the cortical bone thickness (mm) and bone mineral density (BMD) within the cortical bone and total bone area were calculated with the help of CT scanning. Results: The BMD and cortical bone thickness in mandibular alveolus were significantly higher than those of the maxilla (p < 0.05). The PTV values ranged from -3.2 to 4.8 for 12 weeks of loading showing clinically stable mini-implants. PTV at insertion was significantly correlated with IT (-0.51), bone density (-0.48), cortical bone thickness (-0.42) (p < 0.05) in the mandible, but showed no correlation in the maxilla. PTV before removal was significantly correlated with RT (-0.66) (p < 0.01) in the mandible. Conclusions: These results show that the periotest is a useful method for the evaluation of mini-implant stability, but it can only be applied to limited areas with thick cortical and high density bone such as the mandible.

• Journal of Periodontal and Implant Science
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• 제32권2호
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• pp.379-388
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• 2002

For the success of dental implant, accurate radiographic evaluation is prerequisite for planning the location of the osseointegrated implants and avoiding injury to vital structures. CT/MPR(computed tomography/multiplanar reformation) shows improved visualization of inferior alveolar canal. In order to obtain cross-sectional images parallel to the teeth, the occlusal plane is used to orientate for the axial plane. If the direction of axial plane is not parallel to the occlusal plane, the reformatted cross-sectional scans will be oblique to the planned fixture direction and will not show the actual dimension of the planned fixture's location. If the available bone height which measured in the cross-sectional view is much greater than the actual available bone height, penetration of canal may occur. The aim of this study is to assess the effect of the axial plane to measurement of available bone height for dental implant in computed tomography of the mandible. 40 patients who had made radiographic stents and had taken CT were selected. The sites that were included in the study were 45 molar regions. In the central panoramic scan, the length from alveolar crest to superior border of inferior alveolar canal(available bone height, ABH) was measured in direction of reformatted cross-sectional plane(uncorrected ABH). Then, length from alveolar crest to superior border of canal was measured in direction of stent(corrected ABH). The angle between uncorrected ABH and corrected ABH was measured. From each ABH, available fixture length was decided by $Br{{\aa}}nemark$ system. The results were following ; the difference between two ABHs was statistically significant in both first and second molar(p< 0.01). The percentage of difference more than 1 mm was 8.7% in first molar and 15.5% in second molar. The percentage of difference more than 2 mm was 2.0% in first molar and 6.6% in second molar. The maximum value of difference was 2.5 mm in first molar and 2.2 mm in second molar. The correlations between difference of 2 ABHs and angle was positive correlations in both first and second molar. The correlation coefficient was 0.534 in first molar and 0.728 in second molar. The second molar has a stronger positive correlation. The percentage of disagreement between 2 fixture lengths from two ABHs was 24.4% in first molar and 28.9% in second molar.

• 대한치주과학회:학술대회논문집
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• 대한치주과학회 1998년도 제38회 종합학술대회 연제초록
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• pp.97-98
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• 1998

• 대한치과보철학회:학술대회논문집
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• 대한치과보철학회 2004년도 춘계학술대회
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• pp.72-72
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• 2004

• 대한치과보철학회:학술대회논문집
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• 대한치과보철학회 1997년도 추계학술대회
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• pp.28-28
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• 1997

• 대한치과보철학회:학술대회논문집
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• 대한치과보철학회 2000년도 춘계학술대회
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• pp.44-44
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• 2000

• The korean journal of orthodontics
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• 제38권6호
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• pp.416-426
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• 2008

The purpose of this study was to evaluate the mobility and ratio of the bone-implant contact (BIC) of a sandblasted, large grit and acid-etched (SLA) orthodontic micro-implant. Methods: Ninety-six micro-implants (48 SLA and 48 machined) were implanted in the upper and lower buccal alveolar bone, and palatal bone of four beagle dogs. Two weeks after surgery, orthodontic force (150-200 g) was applied. Two beagles were sacrificed at 4-weeks and the other two at 12-weeks. Histomorphometric comparisons were made between the SLA experimental group and the machined micro-implant as a control group to determine the ratio of contact between the bone and implant. Micro-implant mobility was also evaluated using $Periotest^{(R)}$. Results: Periotest values showed no statistically significant difference in the upper alveolar and palatal bone between groups except for the lower buccal area. BIC in the upper buccal area showed no significant difference between groups both at 4-weeks and 12-weeks. However, both the groups showed a significant difference in BIC ratio in the rest of the experimental areas between 4 weeks and 12 weeks. The experimental group showed active bone remodeling around the bone-implant interface compared to the control group. Conclusions: There were significant differences in the BIC and the Periotest values between the surface-treated and machined micro-implants according to bone quality in the early stage.