• The Journal of Korean Academy of Prosthodontics
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• v.47 no.2
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• pp.240-246
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• 2009

Statement of problem: Insertion of endosseous implants in the atrophic maxilla is often complicated because of lack of supporting bone. Augmentation of the floor of the maxillary sinus with autogenous bone & bone substitute graft has been proven to be a reliable treatment modality, at least in the short term. The aim of this study is to evaluate the factors of implant survival rate associated with maxillary sinus lift with grafts. Material and methods: The sinus floor was augmented with bone grafts derived from modified Caldwell-luctechnique(71 subject, 93 sinus, 180 implants), the autogenous bone or autogenous+Bio-oss. Before implant installation the width and height of the alveolar crest were increased in the first stage procedure in 10 patients while in the other 61 patients augmentation and implant installation could be performed simultaneously width and height of the alveolar crest > 4 mm) or delayed installation. Results: In all case bone volume was sufficients for implant insertion. 14 of 180 inserted implants were lost during follow up and the healing period Patient received implant supported overdenture(5 patients) or fixed bridge(62 patients). Conclusion: Within the limit of the result of this study, we conclude that bone grafting of the floor of the maxillary sinus floor with bone for the insertion of implants might be a reliable treatment modality and the autogenous bone graft and delayed installation method might be the factors for good results.

• The Journal of Korean Academy of Prosthodontics
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• v.33 no.3
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• pp.550-568
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• 1995

The purpose of this study was to observe the effects of early functional on bone formation around titanium plsama sprayed IMZ implants. 15 IMZ implants were inserted on the mandibular premolar areaa in 5 mondgrel dogs. The inplants were divided into 4 groups according to it’s loading schedule : Temporary abutments were connected for functional loading 6weeks, 9weeks, and 12weeks after implants installation in group I, II, and III, respectively. Abutments were not connected in the control group. After polyfluorochrome sequential labeling, all animals were sacrificed and bone sections includig implants and the 1st. molar were removed and processed for histologic evaluation. From light and fluorescence microscopic evaluation as well as histomorphometric and EPMA analysis, following results were obtained : 1. Light microscopically, the osteoid tissues were observed much in the compact bone of unloaded group, and cancellous bone formation observed more in early loaded group. 2. Calcification and remodeling of bone took place faster in loaded group, especially in 6 weeks group. 3. Moderate to severe marginal bone resorption was observed in 6 weeks group, mainly on buccal crest. 4. There was no difference in the percentages of bone-to-metal contact among the experimental groups. 5. In quantitative analysis using EPMA, there was no difference in the content of calcium and phosphorus among the experimental groups, regardless of distance.

• Korean Journal of Cleft Lip And Palate
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• v.9 no.2
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• pp.71-78
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• 2006

The case records of 24 patients in Seoul National University Hospital who had bone grafting of 29 alveolar clefts between 2001 and 2004 were examined. Details were recorded of age, sex, preoperative orthodontictreatment, the time of bone grafting, the type of donor site, cleft width, functional load applicationand the success of grafting as established by lowest marginal bone levels. Using this results and review of literature, we concluded that secondary bone graft with iliac bone before canine eruption with root development of 1/2 to 1/3 provide more favorable results and the functional load introduced to the grafted bone lower the resorption rates.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.38
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• pp.30.1-30.6
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• 2016

Background: The prognosis of wide implants tends to be controversial. While wider implants were initially expected to result in a larger osseointegration area and have higher levels of primary stability, they were reported to have a relatively high rate of failure. The clinical outcome of ultrawide implants of more than 6 mm in diameter was evaluated through a retrospective study. Methods: The investigation was conducted on patients who had received ultrawide implant (${\geq}6mm$ diameter) placements in Seoul National University Bundang Hospital from January 2008 to December 2013. Complications were investigated during the maintenance period, and marginal bone loss was measured using periapical radiography. Primary stability immediately after the implant placement and second stability after second surgery or during impression were measured using $Osstell^{(R)}$ Mentor (Osstell, Sweden) as an implant stability quotient (ISQ). Results: Fifty-eight implants were placed in 53 patients (30 male, 23 female), and they were observed for an average of $50.06{\pm}23.49$ months. The average ISQ value increased from $71.22{\pm}10.26$ to $77.48{\pm}8.98$ (P < 0.005). The primary and secondary stability shows significantly higher at the mandible than at the maxilla (P < 0.001). However, mean survival rate shows 98.28 %. Average marginal bone loss of 0.018 and 0.045 mm were measured at 12 and 24 months after the loading and 0.14 mm at final follow-up date (mean 46.25 months), respectively. Also in this study, the bone loss amount was noticeably small compared to regular implants reported in previous studies. Conclusions: The excellent clinical outcome of ultrawide implants was confirmed. It was determined that an ultrawide implant can be used as an alternative when the bone quality in the posterior teeth is relatively low or when a previous implant has failed.

• The Journal of Advanced Prosthodontics
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• v.8 no.5
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• pp.396-403
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• 2016

PURPOSE. Early loading of implant can be determined by excellent primary stability and characteristic of implant surface. The implant system with recently improved surface can have load application 4-6 weeks after installing in maxilla and mandible. This study evaluated the effect of healing period to the stability of hydrophilic tapered-type implant at maxillary posterior area. MATERIALS AND METHODS. This study included 30 patients treated by hydrophilic tapered-type implants (total 41 implants at maxilla) and classified by two groups depending on healing period. Group 1 (11 patients, 15 implants) was a control group and the healing period was 12 weeks, and Group 2 (19 patients, 26 implants) was test group and the healing period was 6 weeks. Immediately after implant placement, at the first impression taking, implant stability was measured using Osstell Mentor. The patients also took periapical radiographs after restoration delivery, 12 months after restoration and final followup period. The marginal bone loss around the implants was measured using the periapical radiographs. RESULTS. All implants were survived and success rate was 97.56%. The marginal bone loss was less than 1mm after 1 year postoperatively except the one implant. The stabilities of the implants were not correlated with age, healing period until loading, insertion torque (IT), the diameter of fixture and the location of implant. Only the quality of bone in group 2 (6 week) was correlated with the stability of implant. CONCLUSION. Healing period of 6 weeks can make the similar clinical prognosis of implants to that of healing period of 12 weeks if bone quality is carefully considered in case of early loading.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.23 no.2
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• pp.265-275
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• 1993

The purpose of this study was to compare the interpretation results of the panoramic radiographs with those of intraoral radiographs in evaluation of alveolar bone loss. All radiographs were obtained from 100 patients who had visited the Dental Infirmary of Kyungpook National University Hospital for periodontal state evaluation. The results were as follows: The percentages of interpretable sites were 95.9%(94.6% in maxilla, 97.4% in mandible) on the intraoral radiographs, and 90.7%(84.0% in maxilla, 97.3% in mandible) on the panoramic radiographs. The concordance of interpretation scores of marginal bone loss between intraoral and panoramic radiographs was 66.3%(65.6% in maxilla, 66.8% in mandible). And according to the site, the highest concordance was in the distal surface of the mandibular 2nd premolar at 82.0%, and the distal surface of the mandibular 1st premolar(76.8%), the distal surface of the maxillary central incisor(75.8%), the mesial surface of the 2nd premolar (75.0%) in descending order of frequency. According to the interpretation scores of the marginal bone loss, the percentages of concordance between intraoral and panoramic radiographs were the highest on the score 10 at 76.4%, and the lowest on the score 8, 9. And the percentages of concordance were inverse proportional rate from the score 5 to the score 9. Number of the observed sites of the furcation involvement in bitewing and panoramic radiographs were 268 sites, and the percentage of interpretable sites was 92.9% in bitewing radiographs and 86.6% in panoramic radiographs. And the concordance rate of interpretation was 79.5%.

• The Journal of Advanced Prosthodontics
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• v.14 no.2
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• pp.108-121
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• 2022

PURPOSE. The purpose of this study was to evaluate survival rates and marginal bone loss (MBL) of implants in IC-RPDs. MATERIALS AND METHODS. Seventy implants were placed and used as surveyed crowns in 30 RPDs. The survival rates and MBL around implants based on multiple variables, e.g., position, sex, age, opposing dentitions, splinting, type of used retainer, and first year bone loss, were analyzed. Patient reported outcome measures (PROMs) regarding functional/esthetic improvement after IC-RPD treatment, and complications were also inspected. RESULTS. The 100% implant survival rates were observed, and 60 of those implants showed MBL levels less than 1.5 mm. No significant differences in MBL of implants were observed between implant positions (maxilla vs. mandible; P = .341) and type of used retainers (P = .630). The implant MBL of greater than 0.5 mm at 1 year showed significantly higher MBL after that (P < .001). Splinted implant surveyed crowns showed lower MBL in the maxilla (splinted vs. non-splinted; P = .037). There were significant esthetic/functional improvements observed after treatment, but there were no significant differences in esthetic results based on implant position (maxilla vs. mandible). Implants in mandible showed significantly greater improvement in function than implants in the maxilla (P = .002). Prosthetic complication of IC-RPD was not observed frequently. However, 2 abutment teeth among 60 were failed. The bone loss of abutment teeth was lower than MBL of implants in IC-RPDs (P = .001). CONCLUSION. Class I RPD connected to residual teeth and strategically positioned implants as surveyed crowns can be a viable treatment modality.

• Journal of Periodontal and Implant Science
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• v.52 no.3
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• pp.194-205
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• 2022

Purpose: This study aimed to determine the long-term outcomes after peri-implantitis treatment and the factors affecting these outcomes. Methods: This study included 92 implants in 45 patients who had been treated for peri-implantitis. Clinical data on the characteristics of patients and their implants were collected retrospectively. The change in the marginal bone level was calculated by comparing the baseline and the most recently obtained (≥3 years after treatment) radiographs. The primary outcome variable was progression of the disease after the treatment at the implant level, which was defined as further bone loss of >1.0 mm or implant removal. A 2-level binary logistic regression analysis was used to identify the effects of possible factors on the primary outcome. Results: The mean age of the patients was 58.7 years (range, 22-79 years). Progression of peri-implantitis was observed in 64.4% of patients and 63.0% of implants during an observation period of 6.4±2.7 years (mean±standard deviation). Multivariable regression analysis revealed that full compliance to recall visits (P=0.019), smoking (P=0.023), placement of 4 or more implants (P=0.022), and marginal bone loss ≥4 mm at baseline (P=0.027) significantly influenced the treatment outcome. Conclusions: The long-term results of peri-implantitis treatment can be improved by full compliance on the part of patients, whereas it is impaired by smoking, placement of multiple implants, and severe bone loss at baseline. Encouraging patients to stop smoking and to receive supportive care is recommended before treatment.

• The Journal of Advanced Prosthodontics
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• v.15 no.3
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• pp.101-113
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• 2023

PURPOSE. This randomized controlled trial aimed to evaluate the effect of implants' two different diameters and cantilever lengths on the marginal bone loss and stability of mplants supporting maxillary prostheses. MATERIALS AND METHODS. Ninety-six implants were placed in sixteen completely edentulous maxillary ridges. Patients were randomly divided into two groups: Group A, implants were placed with a cantilever to anterior-posterior AP spread length (CL:AP) at a ratio of 1:3; Group B, implants were placed with a CL:AP at a ratio of 1:2. Patients were further divided into four sub-groups: Groups A1, A2, B1, and B2. Groups A1 and B1 received small diameter implants while Groups A2 and B2 received standard diameter implants. Bone height and stability measurements around each implant were performed at 0, 4, 8 and 24 months after definitive prostheses delivery. RESULTS. Statistical analysis of the mean implant stability and height values revealed an insignificant difference between Group A1 and Group A2 at all the different time intervals while significantly higher values in Group B1 in comparison with Group B2. Results also showed significantly higher values in Group A1 in comparison with Group B1 and an insignificant difference between Group A2 and Group B2 at all the different time intervals. CONCLUSION. It can be concluded that the use of small diameter implants placed with a CL:AP at a ratio of 1:3 provided predictable results and that the 1:2 CL:AP significantly induced more critical bone loss in the small diameter implants group, which can significantly reduce long term success and survival of implants

• 대한치주과학회:학술대회논문집
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• 2007.05a
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• pp.34-35
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• 2007