• The Journal of Advanced Prosthodontics
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• 제9권2호
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• pp.99-103
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• 2017

PURPOSE. The purpose of this study was to achieve more retention and stability and to delay or prevent screw loosening. MATERIALS AND METHODS. Twenty implants (Implantium 3.4 mm, Dentium, Seoul, Korea) were divided into 2 groups (n = 20). In the first group, an adhesive material was applied around the screw of the abutments (test group). In the second group, the screws are soaked in saliva (control group). All the screws were torqued under 30 N/cm, Then, the samples were gone through a cyclic fatigue loading process. After cyclic loading, we detorqued screws and calculated detorque value. RESULTS. In comparison with the control group, all the implant screws in the test group were smeared with the adhesive material, showing significant higher detorque value. CONCLUSION. There are significantly higher detorque values in the group with adhesive. It is recommended to make biocompatible adhesive to reduce screw loosening.

• 구강회복응용과학지
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• 제22권4호
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• pp.341-348
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• 2006

Accurate fit of the implant prosthesis is important in ensuring long term success of osseointegrated implant. Inaccurate fit of the implant prosthesis may give rise to complications and mechanical failure. To evaluate fite of the implant prosthesis, the development of the methods of analyzing the degree of misfit is important in clinical practice. To analyze the degree of the misfit of implant prosthesis, modal testing was used. A 2-dimensional finite element modal testing was accomplished. Four 2-dimensional finite element models with various levels of misfit of implant prostheses were constructed. Thickness gauges were simulated to make misfit in the implant prostheses. With eigenvalue analysis, the natural frequencies of the models were found in the frequency domain representation of vibration. According to the difference of degree of misfit, natural frequencies of the models were changed.

• 구강회복응용과학지
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• 제22권3호
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• pp.251-260
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• 2006

Accurate fit of the implant prosthesis is important in ensuring long term success of osseointegrated implant. Inaccurate fit of the implant prosthesis may give rise to complications and mechanical failure. To evaluate fite of the implant prosthesis, the development of the methods of analyzing the degree of misfit is important in clinical practice. To analyze the degree of the misfit of implant prosthesis, modal testing was used. A 2-dimensional finite element modal testing was accomplished. Four 2-dimensional finite element models with various levels of misfit of implant prostheses were constructed. Thickness gauges were simulated to make misfit in the implant prostheses. With eigenvalue analysis, the natural frequencies of the models were found in the frequency domain representation of vibration. According to the difference of degree of misfit, natural frequencies of the models were changed.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제27권2호
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• pp.178-183
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• 2001

Since the introduction of the concept of osseointegration, the success rate of dental implant has increased dramatically. So, the uses of dental implant in the treatment of partially or fully edentulous patients have played an important role in dental rehabilitation. Regardless of high success rate of dental implant, some amounts of fixtures cannot help failing. We can classify dental implant failure according to timing, causative factor, etc. This study is focused on dental implant fixture failure, occurring during preprosthetic stage. There are various reasons that cause implant failure on this periods, such as improper patient selection, poor bone quality, and periimplantitis, etc. We investigate the survival rate of 1058 fixtures, which installed in 306 patients in our clinic from January 1997 to December 1999, according to type, sex, location, fixture length and width, using Kaplan-Meier product-limit method and to compare each other with log-rank test. Overall survival rate was 96.80%, and 33 implants failed over the preprosthetic stage. Our survey data identified posterior location of mandible as being associated with implant failure(P<0.05).

• Archives of Plastic Surgery
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• 제36권2호
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• pp.161-166
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• 2009

Purpose: Using the implant for the breast reconstruction still remains the options, despite the breast reconstruction using autologous tissue is an ideal method. In this study, we used AlloDerm$^{(R)}$ to extend subpectoral pocket for covering implants to reduce implant related complications. Met hods : From January 2005 to June 2007, 18 breasts in 16 patients were reconstructed using implant and AlloDerm$^{(R)}$ immediately after mastectomy. Hospital records, database files, and clinical photographs were reviewed. A ten - point scale was used to evaluate the patient's satisfaction, with a range from 2(poor) to 10(excellent). Results: Mean age of the patients was 38.7 years at the time of operation. Mean weight of removed breast tissue was 287g. AlloDerm$^{(R)}$ was used to extend subpectoral coverage. Any systemic complication was not reported. Breast complication was developed in 4 cases. Implant removal or change was not experienced. Conclusion: Immediate breast reconstruction using Implant is useful methods for certain conditions, when donor tissue is insufficient and breast is non ptotic with round shape. In those cases, extension of muscle coverage using AlloDerm$^{(R)}$ could reduce complications and lead more acceptable results.

• Journal of Korean Dental Science
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• 제17권2호
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• pp.53-63
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• 2024

Purpose: To investigate the effects of simultaneous soft and hard tissue augmentation and the addition of polydeoxyribonucleotide (PDRN) on regenerative outcomes. Materials and Methods: In five mongrel dogs, chronic ridge defects were established in both mandibles. Six implants were placed in the mandible, producing buccal dehiscence defects. The implants were randomly allocated to one of the following groups: 1) control: no treatment; 2) GBR: guided bone regeneration (GBR) only; 3) GBR/PDRN: GBR+PDRN application to bone substitute particles; 4) GBR/CTG: GBR+connective tissue grafting (CTG); 5) GBR/VCMX: GBR+soft tissue augmentation using volume stable collagen matrix (VCMX); and 6) group GBR/VCMX/PDRN: GBR+VCMX soaked with PDRN. The healing abutments were connected to the implants to provide additional room for tissue regeneration. Submerged healing was achieved. The animals were euthanized after four months. Histological and histomorphometric analyses were then performed. Results: Healing abutments were gradually exposed during the healing period. Histologically, minimal new bone formation was observed in the dehiscence defects. No specific differences were found between the groups regarding collagen fiber orientation and density in the augmented area. No traces of CTG or VCMX were detected. Histomorphometrically, the mean tissue thickness was greater in the control group than in the other groups above the implant shoulder (IS). Below the IS level, the CTG and PDRN groups exhibited more favorable tissue thickness than the other groups. Conclusion: Failure of submerged healing after tissue augmentation deteriorated the tissue contour. PDRN appears to have a positive effect on soft tissues.

• Archives of Plastic Surgery
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• 제49권5호
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• pp.580-586
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• 2022

Background Appropriate position of the nipple-areolar complex (NAC) is crucial following nipple-sparing mastectomy (NSM). The prevention of NAC malposition in two-stage implant-based breast reconstruction has not been well described, and the efficacy of the techniques has not been evaluated. This study aimed to evaluate the efficacy of our technique to prevent NAC malposition in patients who underwent implant-based breast reconstruction after NSM. Methods Patients who underwent two-stage implant-based breast reconstruction with NSM between January 2012 and December 2019 were included. We used a surgical technique to fix the NAC to the rigid base, assuming a pocket-like appearance, with pectoralis major muscle and lateral adipofascial flap at the time of tissue expander (TE) insertion. Patients were classified into two groups based on the performance of the technique for the prevention of NAC malposition. Results In 35 patients who underwent implant-based breast reconstruction after NSM, the clavicle-to-nipple distance ratio was 96.0±5.0% in those who underwent NAC fixation and 86.1±11.5% in those who did not undergo NAC fixation. Conclusions Using our technique, NAC malposition could be prevented in two-stage implant-based breast reconstruction. NAC fixation during TE insertion was found to be extremely effective. This procedure successfully prevented NAC malposition without the formation of extra scars.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제38권
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• pp.19.1-19.4
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• 2016

Background: Implant surgery has become popular with the advance of surgical techniques such as sinus lifting, guided bone regeneration, and block bone graft. However, there were no data about the frequency of bone graft during implant surgery. The purpose of this study was to report the frequency and types of bone graft depending on dental implant patients' profile to complement the database regarding implant surgery. Methods: The implant operations had been performed from January 2006 to October 2014. The upper and lower jaws were divided into six sextants. A total of 792 sextants were included in this study. Patient information including sex, age, sites, bone graft, and types of bone were investigated. Results: A total of 1512 implants had been placed. Male and female sextants were 421 and 371, respectively (M:F = 1:0.88). Average age was 54.3 (ranging from 20 to 88 years old). Implants were placed in the posterior maxilla (322 sextants, 40.7 %), posterior mandible (286 sextants, 36.1 %), anterior maxilla (127 sextants, 16.1 %), and anterior mandible (57 sextants, 7.2 %). Bone graft was performed in 50.3 % of the sextants. Among the bone grafted sites, sinus lifting with lateral approach (22.1 %) and guided bone regeneration (22.7 %) were performed most frequently. Conclusions: Bone graft in implant surgery was necessary to augment defects. More than half of the sextants needed bone graft for implant installation.

• Journal of Periodontal and Implant Science
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• 제37권3호
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• pp.535-542
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• 2007

Background : Repeated dis/re-connection of implant abutment caused bone loss around implant fixtures due to the new formation of biologic width of the mucosal-implant barrier. The aim of this clinical study was to evaluate whether the repeated dis/re-connection of implant abutment cause bone loss clinically and the effect of cleansing methods on a bone loss during the early healing period. Methods : A total 50 implants were installed in 20 patients and repeated dis/re-connection of abutment was performed at the time of surgery and once per week for 12 weeks. 0.9% normal saline solution as group1 and 0.1% chlorhexidine solution as group 2 was used to clean abutments. All patients had radiographs taken at the placement of implant and 4, 8, and 12 weeks postoperatively. The data for bone loss around implant were analyzed. Results: The marginal bone loss at 12 weeks were $1.28{\pm}0.51mm$, $1,32{\pm}0,57mm$ in the mesial and distal sides in group1, $1.94{\pm}0.75mm$, $1.81{\pm}0.84mm$ in group 2, respectively. In view of marginal bone loss, there was not a significant statistical difference between groups. Conclusions : Repeated dis/re-connection of implant abutment may not cause marginal bone loss around implant fixture although limited samples and short-term observation period. In spite of more bone loss in group 2, there was no statistical significant difference between groups. In context of those results, the clinical significance of the repeated dis/re-connection of implant abutment and the cleansing method of abutments is debatable when it comes to marginal bone loss during early healing period.

• Archives of Plastic Surgery
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• 제37권1호
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• pp.26-30
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• 2010

Purpose: Common complications of immediate breast reconstruction with implant are capsular contracture, malposition of implant, hematoma and seroma. Especially, the most severe complication is implant exposure caused by inflammation or necrosis of skin flap margin of mastectomy site. This article reports the experience of cases of salvage in such an exposure of implant. Methods: From July, 2002 to Feb., 2009, sixty-five patients who underwent immediate breast reconstruction with implant were retrospectively analyzed. Exposure of implant was happened in 5 of 65 patients and they were treated at out patient district. Two of five patients were reconstructed with saline implnt and all of them underwent the enveloping of the implant with AlloDerm$^{(R)}$ and Serratus muscle flap. Remaning three patients were reconstructed with silicone implant and all of them underwent the enveloping of the implant with AlloDerm$^{(R)}$. Results: In the group of patients who underwent reconstruction with saline implant, implant exposure was found in one patient due to partial necrosis of the margin of skin flap and debridement and primary repair were done. In the other one patient, dressing with antibiotic ointment were done. And debridement and primary repair were proceeded. In the group of patients who underwent reconstruction with silicone implant, implant exposure was found in one patient. After removal of the implant, tissue expansion was done and a new silicone implant was inserted. Implant exposure were found in the other two patients, antibiotics ointment application and primarily repaired. Conclusion: It was the common knowledge that the exposed implant should be removed. But salvage of the exposed implants may be possible with proper treatment. Four of five patients (80%) with exposed breast implant were salvaged with conservative management.