• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.38 no.6
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• pp.371-378
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• 2012

Many longitudinal studies have reported the successful osseointegration of dental implants, with survival rates approaching 90-95%. However, implants regarded as a "success" may have also failed to undergo osseointegration. A variety of complications and failures have been observed, including implant fracture - a rare and delayed biomechanical complication with serious clinical outcomes. Given the increasing popularity of dental implants, an increase in the number of failures due to late fractures is expected. This study sought to determine the rate of implant fractures and factors associated with its development. This retrospective evaluation analyzed implants placed at Wonkwang Dental Hospital (from 1996 to the present). In our study we found that the frequency of dental implant fractures was very low (0.23%, 8 implant fractures out of 3,500 implants placed). All observed fractures were associated with hybrid-surface threaded implants (with diameter of 4.0 or 3.75 mm). Prosthetic or abutment screw loosening preceded implant fracture in a majority of these cases.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.49 no.3
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• pp.114-124
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• 2023

Dental implants have been utilized for many years to treat individuals with missing teeth. To optimize the long-term success rate of such implants, new designs, surfaces, and materials have been analyzed. It is important for the clinician to have a background in the field of implant surface design, to be familiar with the strengths and limitations of the available options, and to be aware of the alterations in surface structure that may occur following installation. This article provides a detailed review of the structure and the surface characteristics of dental implants, the modifications of implant surface, as well as the methods of evaluating implant surface structure. Moreover, it provides information concerning the structural changes that may take place at the time of dental implant placement. It is important for clinicians to be aware of such changes to plan and execute implant procedures with the highest possible success and implant survival rates.

• Journal of Periodontal and Implant Science
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• v.49 no.5
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• pp.287-298
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• 2019

Purpose: The aim of this retrospective study was to determine the prevalence of early implant failure using a single implant system and to identify the factors contributing to early implant failure. Methods: Patients who received implant treatment with a single implant system ($Luna^{(R)}$, Shinhung, Seoul, Korea) at Dankook University Dental Hospital from 2015 to 2017 were enrolled. The following data were collected for analysis: sex and age of the patient, seniority of the surgeon, diameter and length of the implant, position in the dental arch, access approach for sinus-floor elevation, and type of guided bone regeneration (GBR) procedure. The effect of each predictor was evaluated using the crude hazard ratio and the adjusted hazard ratio (aHR) in univariate and multivariate Cox regression analyses, respectively. Results: This study analyzed 1,031 implants in 409 patients, who comprised 169 females and 240 males with a median age of 54 years (interquartile range [IQR], 47-61 years) and were followed up for a median of 7.2 months (IQR, 5.6-9.9 months) after implant placement. Thirty-five implants were removed prior to final prosthesis delivery, and the cumulative survival rate in the early phase at the implant level was 95.6%. Multivariate regression analysis revealed that seniority of the surgeon (residents: aHR=2.86; 95% confidence interval [CI], 1.37-5.94) and the jaw in which the implant was placed (mandible: aHR=2.31; 95% CI, 1.12-4.76) exerted statistically significant effects on early implant failure after adjusting for sex, age, dimensions of the implant, and type of GBR procedure (preoperative and/or simultaneous) (P<0.05). Conclusions: Prospective studies are warranted to further elucidate the factors contributing to early implant failure. In the meantime, surgeons should receive appropriate training and carefully select the bone bed in order to minimize the risk of early implant failure.

• Journal of Korean Dental Science
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• v.1 no.1
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• pp.4-9
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• 2008

Purpose : This study sought to examine the aspects of crestal bone resorption and to evaluate the clinical outcomes of the TiUnite$^{(R)}$ (Nobel Biocare, Sweden) anodized implant system. Materials and Methods : Among the 67 patients (211 fixtures) who were treated using TiUnite(r) implants at Seoul National University Bundang Hospital between March 2004 and January 2007, 26 (91 fixtures) were considered in this study. Initial and secondary stabilities were measured using Periotest$^{(R)}$ and Ostell(tm) Mentor. The radiographic evaluation of crestal bone resorption was carried out by measuring the change in crestal bone level at the time of surgery compared to that 1 year after loading. Panoramic radiograph and periapical radiograph were used. Based on the radiographic findings, the shapes of crestal bone resorption were classified. Results : The average amount of crestal bone resorption after 1 year of functional implant loading was 0.30 mm. There was no saucerization in 40 implant fixtures (43.9%), although more than 1 thread were exposed in 51 implant fixtures (56.6%). The success rate of the implants was 94.5%, and the survival rate was 100%. Conclusions : Good clinical outcomes and minor crestal bone resorption were noted in this study. Saucerization for the establishment of biological width was not a general finding in the TiUnite$^{(R)}$ anodized implant system.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.35 no.5
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• pp.367-371
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• 2009

Purpose: The purpose of this study was to evaluate the feasibility of the outfracture osteotomy sinus graft technique with the evaluation of 5-year survival rate of the implants placed in the atrophic edentulous posterior maxillary area. Materials and methods: One hundred and thirteen cases of 96 patients who visited our center from Aug 2004 to July 2009 and were diagnosed as atrophic edentulous maxillary alveolar ridge, were selected and underwent augmentation sinus surgery with outfracture osteotomy technique. Feasibility of the outfracture osteotomy technique was investigated with clinical and radiographic evaluation to assess the survival rate of the total dental implants in augmentation sinus surgery of this new kind. Total fixture number available in follow-up period was 179, in which the lost 10 patients were excluded out of 96 patients. Results: Five-year cumulative survival rate was 97.2% with 5 failures of total 179 fixtures. The average follow-up period was 29 and a half months, with the minimum and maximum follow-up periods of 4 months 21 days and 59 months 14 days, respectively. Conclusion: Traditional infracture technique is a popular method for an augmentation sinus surgery. The authors modified this classical method by outfracturing and readapting the bony window after sinus graft, with excellent treatment results evidenced by high survival rate of 97.2% (174 out of 179 fixtures), which proves the feasibility of the newly-designed outfracture osteotomy sinus graft technique.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.38
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• pp.50.1-50.6
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• 2016

Background: The aim of this study was to evaluate the clinical outcomes of implants that were placed within the maxillary sinus that has a perforated sinus membrane by the lateral window approach. Methods: We examined the medical records of the patients who had implants placed within the maxillary sinus that has a perforated sinus membrane by the lateral approach at the Department of Oral and Maxillofacial Surgery of Chonnam National University Dental Hospital from January 2009 to December 2015. There were 41 patients (male:female = 28:13). The mean age of patients was $57.2{\pm}7.2years$ at the time of operation (range, 20-76 years). The mean follow-up duration was 2.1 years (range, 0.5-5 years) after implant placement. Regarding the method of sinus elevation, only the lateral approach was included in this study. Results: Ninety-nine implants were placed in 41 patients whose sinus membranes were perforated during lateral approach. The perforated sinus membranes were repaired with a resorbable collagen membrane. Simultaneous implant placements with sinus bone grafting were performed in 37 patients, whereas delayed placements were done in four patients. The average residual bone height was $3.4{\pm}2.0mm$ in cases of simultaneous implant placement and $0.6{\pm}0.9mm$ in cases of delayed placement. Maxillary bone graft with implant placement, performed on the patients with a perforated maxillary sinus membrane did not fail, and the cumulative implant survival rate was 100%. Conclusions: In patients with perforations of the sinus mucosa, sinus elevation and implant placement are possible regardless of the location and size of membrane perforation. Repair using resorbable collagen membrane is a predictable and reliable technique.

• The Journal of the Korean dental association
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• v.47 no.9
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• pp.585-595
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• 2009

Purpose : The aim of this study was to compare surgical complications between simple implant placement and implant placement combined with complicated surgical procedures. We also evaluated prosthetic complications according to the specific types of prosthesis. Material and Method : A retrospective analysis of dental chart of patients who was performed implant therapy during the period from June 2003 to December 2005 was carried out. This study was performed on 408 patients (208 male, 200 female). In addition, 1671 implants were performed. Based on their medical record and radiographs, the authors evaluated surgical and prosthetic complications, surgical procedures accompanied at the time of implant, risk factors of implant failure etc. Result : Surgical complications were developed on 358 implants(21.4% on total placed implants) and wound dehiscence was most prevalent complication. On maxillary posterior area, surgical complications developed more frequently on implants with major surgery and showed a significant difference. And complication rate of implants accompanied with GBR was higher than that of simple implants placement and also showed significant difference. The implant supported prosthesis showed no statistical difference in the occurrence of complications according to the types of prosthesis, and food retention was the most common post-prosthetic complication. Also we speculated that length and width of implant showed significant correlation to the failure of implant primary osseointegration. Conclusion : Based on the result, clinician should provide more careful maintenance for patients with implant placement accompanied by complicated surgical procedure. And periodic maintenance for the patient is requested for long-term survival of implant therapy.

• The Journal of Advanced Prosthodontics
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• v.8 no.4
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• pp.313-320
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• 2016

PURPOSE. The aim of this study was to evaluate the clinical findings and patient satisfaction on implant overdenture designed with Locator implant attachment or Locator bar attachment in mandibular edentulous patients. MATERIALS AND METHODS. Implant survival rate, marginal bone loss, probing depth, peri-implant inflammation, bleeding, plaque, calculus, complications, and satisfaction were evaluated on sixteen patients who were treated with mandibular overdenture and have used it for at least 1 year (Locator implant attachment: n=8, Locator bar attachment: n=8). RESULTS. Marginal bone loss, probing depth, plaque index of the Locator bar attachment group were significantly lower than the Locator implant attachment group (P<.05). There was no significant difference on bleeding, peri-implant inflammation, and patient satisfaction between the two denture types (P>.05). The replacement of the attachment components was the most common complication in both groups. Although there was no correlation between marginal bone loss and plaque index, a significant correlation was found between marginal bone loss and probing depth. CONCLUSION. The Locator bar attachment group indicates lesser marginal bone loss and need for maintenance, as compared with the Locator implant attachment group. This may be due to the splinting effect among implants rather than the types of Locator attachment.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.42 no.3
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• pp.139-143
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• 2016

Objectives: If teeth are missing, super-eruption of teeth in the opposing arch can occur in the area and can change the occlusal plane. When missing teeth are replaced with implants, the oral surgeon must determine whether or not the super-erupted teeth need to be treated in order to normalize the occlusal plane. In this study, we evaluated the clinical prognosis of dentition after implant placement and prosthetic treatment were completed in an occlusal plane altered by super-erupted teeth in the opposing arch without additional treatment of the super-erupted teeth. Materials and Methods: Twenty-two patients (9 males, 13 females) were treated with implants and prosthetics without addressing the super-erupted opposing dentition from April 2004 to August 2012 at Seoul National University Bundang Hospital. A total of 33 implants were placed. Values of crestal bone loss, survival rates, and surgical and prosthetic complications for an average of 29.6 months after prosthetic loading were recorded. Results: In one case, the cover screw was exposed after implant surgery. The mean crestal bone loss was $0.09{\pm}0.30mm$. Of the 33 implants, 31 survived, a survival rate of 93.94%. A prosthetic complication occurred in one case but functioned well after correction. Conclusion: Favorable clinical results from prosthetic complications, crestal bone loss, and implant survival rates were exhibited in implants next to a super-erupted opposing tooth.

• Korean Journal of Cleft Lip And Palate
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• v.5 no.2
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• pp.85-93
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• 2002

Simultaneous implant installation with bone graft was performed in 15 cases. Four cases were cleft alveolus patients. 56 implants were placed immediately with block bone grafts. 2 cases were cranial bone grafts and the others were iliac bone grafts. Three of 56 implants were lost(94.6% Survival rate). One of three was cleft alveolus case. The cleft alveolus patients with simultaneous implants installation showed functional and esthetic results without infraocclusion and positional changes. Bergland index was considered to be type I after 12 months later. Immediate implant installation with bone graft is one of choice of treatment in closing cleft alveolus hoping simultaneous implant installation could be related with function which might result in less resorption of graft. Functional and esthetic results are satisfaction ; there was no infraocclusion and positional changes.