• The Journal of Advanced Prosthodontics
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• 제6권6호
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• pp.491-497
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• 2014

PURPOSE. This study evaluated the influence of abutment materials on the stability of the implant-abutment joint in internal conical connection type implant systems. MATERIALS AND METHODS. Internal conical connection type implants, cement-retained abutments, and tungsten carbide-coated abutment screws were used. The abutments were fabricated with commercially pure grade 3 titanium (group T3), commercially pure grade 4 titanium (group T4), or Ti-6Al-4V (group TA) (n=5, each). In order to assess the amount of settlement after abutment fixation, a 30-Ncm tightening torque was applied, then the change in length before and after tightening the abutment screw was measured, and the preload exerted was recorded. The compressive bending strength was measured under the ISO14801 conditions. In order to determine whether there were significant changes in settlement, preload, and compressive bending strength before and after abutment fixation depending on abutment materials, one-way ANOVA and Tukey's HSD post-hoc test was performed. RESULTS. Group TA exhibited the smallest mean change in the combined length of the implant and abutment before and after fixation, and no difference was observed between groups T3 and T4 (P>.05). Group TA exhibited the highest preload and compressive bending strength values, followed by T4, then T3 (P<.001). CONCLUSION. The abutment material can influence the stability of the interface in internal conical connection type implant systems. The strength of the abutment material was inversely correlated with settlement, and positively correlated with compressive bending strength. Preload was inversely proportional to the frictional coefficient of the abutment material.

• 구강회복응용과학지
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• 제31권3호
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• pp.186-194
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• 2015

목적: 임플란트 위치와 길이가 하악 후방연장 가철성 국소의치(DERPD)와 연관된 임플란트의 응력 분포와 변위에 미치는 영향을 알아보는 것이다. 연구 재료 및 방법: #35, 36, 37이 소실된 시상절단면의 후방연장모형과 가철성 국소의치를 기본모형으로 사용했다. NX 9.0으로 7개의 모델을 디자인했다. 모델 A, B, C에서 각각 11, 6, 4 mm 길이의 임플란트가 #37 인공치 하방에 위치되었다. 모델 D, E, F에서 각각 11, 6, 4 mm의 임플란트가 #36 인공치 하방에 위치되었다. 모델 G는 임플란트가 없었다. 수직하중(250 N)을 #36의 중심와에 가했고, 유한요소 분석프로그램을 이용해 von Mises stress와 변위를 관찰했다. 결과: #37에 위치한 임플란트는 #36에 위치한 것과 비교시 주변골에 더 낮은 응력집중도를, #36에 위치한 임플란트는 #37에 위치한 것보다 더 적은 변위를 보였다. 결론: 임플란트 지지형 가철성 국소의치에서 후방부에 위치한 임플란트는 전방부에서보다 더 이점을 가지며, 길이가 더 긴 임플란트의 사용은 응력분산을 위해서 중요하다.

• Journal of Periodontal and Implant Science
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• 제42권1호
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• pp.13-19
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• 2012

Purpose: The aim of this study was to examine whether a previous peri-implantitis site can affect osseointegration, by comparing implant placement at a site where peri-implantitis was present and at a normal bone site. A second aim of this study was to identify the tissue and bone reaction after treating the contaminated implant surface to determine the optimal treatment for peri-implant diseases. Methods: A peri-implant mucositis model for dogs was prepared to determine the optimal treatment option for peri-implant mucositis or peri-implantitis. The implants were inserted partially to a length of 6 mm. The upper 4 mm part of the dental implants was exposed to the oral environment. Simple exposure for 2 weeks contaminated the implant surface. After 2 weeks, the implants were divided into three groups: untreated, swabbed with saline, and swabbed with $H_2O_2$. Three implants from each group were placed to the full length in the same spot. The other three implants were placed fully into newly prepared bone. After eight weeks of healing, the animals were sacrificed. Ground sections, representing the mid-buccal-lingual plane, were prepared for histological analysis. The analysis was evaluated clinically and histometrically. Results: The untreated implants and $H_2O_2$-swabbed implants showed gingival inflammation. Only the saline-swabbed implant group showed re-osseointegration and no gingival inflammation. There was no difference in regeneration height or bone-to-implant contact between in situ implant placement and implant placement in the new bone site. Conclusions: It can be concluded that cleaning with saline may be effective in implant decontamination. After implant surface decontamination, implant installation in a previous peri-implant diseased site may not interfere with osseointegration.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제31권4호
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• pp.306-313
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• 2009

Objectives: The aim of the present review was to evaluate survival rate and various factors associated with survival of osseointegrated implants. Patients and methods: The clinical comparisons were performed to evaluate survival rate of 794 endosseous implants that had been inserted between 2004 through 2008 in relation to sex and age of patients, position of implant, implant system and surface characteristics, length and diameter of implant, and bone graft technique. Results: The survival rate of implant was 94.3% in posterior area of maxilla and 98.6% in posterior area of mandible by position of implant, a statistically significant difference. As to diameter of implant, survival rate was 98.4% between the 4.0 and 4.5 mm and 75.0% in larger than 5.0 mm, that was statistically significant difference. There was a statistically significant difference regard to bone graft and surgical technique. The implant survival rate was 89.0% in a placement site which performed sinus lifting, and in case of implant placement with guided bone regeneration technique and without bone grafting was 97.6% and 100% each. Conclusion: According to these findings, this study establishes a relationship between survival rate of implant and position, surface characteristics, diameter of implant and bone graft technique.

• The Journal of Advanced Prosthodontics
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• 제2권4호
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• pp.128-133
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• 2010

PURPOSE. The purpose of this study was to compare the accuracy of the implant master cast according to the type (pick-up, transfer) and the length (long, short) of the impression copings. MATERIALS AND METHODS. The metal master cast was fabricated with three internal connection type implant analogs (Osstem GS III analog), embedded parallel and with $10^{\circ}$ of mesial angulation to the center analog. Four types of impression coping were prepared with different combinations of types (transfer, pick-up) and lengths (long, short) of the coping. The impressions were made using vinyl polysiloxane (one step, heavy + light body) with an individual tray, and 10 impressions were made for each group. Eventually, 40 experimental casts were produced. Then, the difference in the distance between the master cast and the experimental cast were measured, and the error rate was determined. The analysis of variance was performed using the SPSS (v 12.0) program (${\alpha}$= .05), and the statistical significance was set at P < .05. RESULTS. The ANOVA showed that the pick-up type impression coping exhibited a significantly lower error rate than the transfer type. However, no significant difference was observed with respect to the length of the impression coping. Additionally, no significant difference was observed between the parallel and mesial angulated groups. CONCLUSION. Within the limitations of this study, the pick-up type impression coping exhibited a more accurate implant master cast than the transfer type in parallel group. The accuracy of the implant master cast did not differ for different lengths of impression coping of at least 11 mm. Additionally, the accuracy of the implant cast was not different for the parallel and $10^{\circ}$ mesial angulated groups.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제34권6호
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• pp.440-448
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• 2012

Purpose: The purpose of this study was to evaluate marginal bone loss of the alveolar crest on implants with or without guided bone regeneration and variables that have influenced. Methods: The clinical evaluation were performed for survival rate and marginal bone loss of 161 endosseous implants installed with guided bone regeneration (GBR) in 83 patients from September 2009 to October 2010 in relation to sex and age of patients, position of implant, implant system, length and diameter of implant. Study group (n=42) implant with GBR procedure, control group (n=41) implant without GBR technique. Simultaneous GBR approach using resorbable membranes combined with autogenous bone graft or freeze-dried bone allograft or combination. Radiographic examinations were conducted at healing abutment connection and latest visit. Marginal bone level was measured. Results: Mean marginal bone loss was 0.73 mm in study group, 0.63 mm in control group. Implants in maxillary anterior area (1.21 mm) were statistically significant in study group (P<0.05), maxillary posterior area (0.81 mm) in control group (P<0.05). Mean marginal bone loss 1.47 mm for implants with diameter 3.4 mm, 0.83 mm for implants of control group with diameter 4.0 mm (P<0.05). Some graft materials showed an increased marginal bone loss but no statistically significant influence of sex, implant type or length. Conclusion: According to these findings, this study demonstrated the amount of marginal bone loss around implant has maintained a relative stable during follow-up periods. We conclude that implants with GBR had similar survival rate and crestal bone level compared with implants in native bone.

• Journal of Oral Medicine and Pain
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• 제39권4호
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• pp.133-139
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• 2014

Purpose: There have been reports regarding the various factors associated with the level of discomfort and recovery from neurosensory symptoms in patients with trigeminal nerve injury. However, the contributing factors remain uncertain and poorly understood. The purpose of this paper was to investigate the possible association between various factors expected to affect neurosensory discomfort and recovery in patients with mandibular nerve injury after dental implant surgery. Methods: Eighty-nine post-dental implant surgery patients with mandibular nerve injury were enrolled in this retrospective analysis. A medical records review of the patients was done to determine if the patients' improvement was related to pain intensity, the length of time between the injury and removal of the implant or the depth of penetration of the implant into the mandibular canal as determined by cone-beam computed tomography. Results: There was no significant linear relationship between pain intensity and symptomatic improvement (p=0.319). There was no significant linear relationship between the level of mandibular canal penetration and either pain intensity (p=0.588) or symptomatic improvement (p=0.760). There was a statistically significant linear relationship between length of time before the injury was treated, both with pain intensity (p=0.004), and symptomatic improvement (p=0.024). Conclusions: Our findings indicate that the length of time between nerve injury and initiation of conservative treatment is more closely related to the pain intensity and symptomatic improvement than other factors, including the level of mandibular canal invasion. Additionally, increased pain intensity and decreased symptomatic improvement can be expected over time, because of this linear trend. Therefore, although direct injury to the nerve is the most important factor contributing to a neurosensory disturbances, early neurosensory assessment and initiation of conservative treatment should be done to optimize recovery.

• 대한치과보철학회지
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• 제30권4호
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• pp.611-621
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• 1992

저자는 두개의 브로네마트 임플란트를 지대치로 하는 가공의치를 제작할 때 임플란트의 길이에 따른 임플란트 주위 조직의 응력분산양상을 평가하기 위하여 임플란트의 길이가 각각 10mm, 7mm, 5mm인 여섯가지의 실험모형을 제작하고 가공의치 중아부에 64kg의 수직하중을 가하여 2차원적 광탄성응력분석 실험을 행하여 비교 분석 해본 바, 다음과 같은 결론을 얻었다. 1. 여섯가지 실험모형 중 응력분산 양상은 실험모형 I (10mm, 10mm)일 경우가 가장 좋았다. 2. 근심과 원심에 같은 길이의 임플란트를 매식하였을 경우, 응력은 대체로 임플란트 표면적의 감소에 비례하여 증가하였다. 3. 근심과 원심에 다른 길이의 임플란트를 매식하였을 경우, 짧은 쪽 임플란트의 경부에 응력이 집중되었다.

• 대한치과의사협회지
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• 제48권8호
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• pp.615-620
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• 2010

Purpose: The short dental implant is considered as possible solution in the alveolar bone height deficient cases. The aim of this study was to evaluate clinical availability of short implants by measuring the marginal bone loss of short length implants and comparing with that of conventional length implants. Materials and Methods: The groups were composed of patients who had received at least one implant. The samples of this study were selected from patients who with functional loading after prosthetic treatment for 1 year follow up period. The implants with a length of 5.7 mm and 6mm were considered short. (Bicon Dental implants, USA). The experiment group was composed of $4.5{\times}6mm$, $5{\times}6mm$, $6{\times}5.7mm$ implants (total 18 implants were placed in 14 patients, 8 on maxilla, 10 on mandible). The control group was composed of $4.5{\times}8mm$, $5{\times}8mm$, $4.5{\times}11mm$, $5{\times}11mm$. All implants were selected only by implants placed on molar area. We evaluated marginal bone loss in radiographic images at baseline (implant loading) and 3, 6, 12 months after loading. Additionally, crown-to-implant ratio was evaluated, and marginal bone loss according to crown-to-implant ratio after functional loading was analyzed. Results: The short implant group had a mean marginal bone level of $-0.52{\pm}0.69mm$; the 8mm group, $-0.22{\pm}0.82mm$; and the II mm group, $-0.10{\pm}1.09mm$ after I year of functional loading. But significant differences were not detected between three groups at every follow-up period. Crown-to-implant ratio in short implant group was $1.55{\pm}0.23$; 8mm group was $1.15{\pm}0.18$; and 11mm group was $0.92{\pm}0.15$. Additionally, significant differences between three groups were founded. (P<.0001) The greatest marginal bone loss after 1 year follow-up was founded at crown-to-implant ratio 1~1.49 range in short implant. Conclusion: The marginal bone loss of short implants was comparable to that of long implants. So, the short implants can be a clinically acceptable option.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제27권1호
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• pp.39-47
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• 2005

The purpose of this study is to review the prognosis of the TG Osseotite implant(3i Co, USA) placed in partial edentulous area of oral cavity and to suspect the possible causes leading to failure. 124 TG Osseotite implants that had been inserted between 2000 - 2002 were followed up for 2 years(avg : 9.5 months) in function. Medical records, and radiographs were evaluated and analyzed by the over all success rate, gender and age factor, general disease, implant fixture length and diameter, implant site, bone density, and various surgical methods. Chi square test was used statistically. Of the 124 TG Osseotite implants, 9 implants(7.3%) were removed in early phase and 3 implants(2.4%) were in late phase. The cumulative survival rate was 90.2%. The failure of the TG Osseotite implant was closely related with the use of bone graft techniques such as sinus elevation or immediate implantation and not with the age, sex, general disease, implant site, bone density of implanted site. The failure of the TG Osseotite implant was well developed when it was the wide type of implant and it was inserted for single tooth replacement. The developement of peri-implantitis was the most important factor in the failure of the TG Osseotite implant.