• The Journal of Korean Academy of Prosthodontics
• /
• v.47 no.3
• /
• pp.266-272
• /
• 2009

Statement of problem: The number of edentulous patients is increasing due to an aging society, which leads to increased demands and interests on implant restorations. Implant restorations are an effective treatment method for both complete and partially edentulous patients, and the success rate has been reported to be high. But because of the increased use of implants in various situations have resulted in frequent reports of failures on implant restorations. Various efforts to overcome these failures have been made. Purpose: The aim of this study was to investigate the statistic survival rate of dental implants on patients who were treated at Dankook University Dental Hospital during the past 10 years based on their charts. Materials and methods :The research was made for two different periods of time; The first investigation was for patients from August, 1998 to August, 2003 and the second was for patients from September, 2003 to April, 2007. Information on the number of implants placed, the location and distribution of implants, the duration between the first and second surgery, and the survival rate of implants were investigated from the patients'charts. Results: 1. According to the first investigation, 1680 implants were placed on 612 patients and the second investigation showed 2438 implants placed on 933 patients. Thus a total of 4118 implants on 1545 patients. 2. Among the 1545 patients, 884 patients were male (57.2 %) and 661 patients were female (42.8%). Out of 4118 implants, 1739 implants (42.2%) were placed on the maxilla, and 2379 implants (57.8%) on the mandible. Implants were placed most frequently in the posterior region of the mandible. A total of 2043 implants (53.2%) were placed in this region. 3. According to the first investigation, 57 out of 1680, implants failed, while from the second investigation, 17 out of 2438 implants were reported as failure. In total, 74 implants failed, which results in a 98.2% survival rate. 4. The average duration between the first and the second surgeries in maxillas decreased from 7.4 months to 6.8 months. The duration also decreased from 5.6 months to 5.0 months in mandibles. Conclusion: As shown in the results, the number of placed implants and the survival rate of implants were higher in the second investigation than that of the first investigation. And the time spent after the first surgery to the second surgery was less in the second investigation. Consequently, it can be presumed that the demand and consumption of dental implants as well as the survival rate will increase in the future.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.28 no.3
• /
• pp.253-268
• /
• 2012

Full-mouth reconstruction of a patient using dental implants is a challenge if there is vertical and horizontal bone resorption, since this includes the gingival area and restricts the position of the implants. however, hard- and soft-tissue grafting may allow the implants to be placed into the desired position. Although it is possible to regenerate lost tissues, an alternative is to use fixed detachable prostheses that restore the function and the esthetics of the gingiva and teeth. Various material combinations including metal/acrylic, metal/ceramic, and zirconia/ceramic have been used for constructing this type of restoration. Other problems include wear, separation or fracture of the resin teeth from the metal/acrylic prosthesis, chipping or fracture of porcelain from the metal/ceramic or zirconia/ceramic prosthesis, and fracture of the framework in some free-end prostheses. With virtually unbreakable, chip-proof, life-like nature, monolithic zirconia frameworks can prospectively replace other framework materials. This clinical report describes the restoration of a patient with complete fixed detachable maxillary and mandibular prostheses made of monolithic zirconia with dental implants. The occluding surfaces were made of monolithic zirconia, to decrease the risk of chipping or fracture. The prostheses were esthetically pleasing, and no clinical complications have been reported after two years.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.17 no.3
• /
• pp.220-230
• /
• 1995

In this report, a case is presented in which resected mandible was reconstructed immediately with vascularized bone graft and adjunctive implantation of osseointegrated dental implants. The primary was central odontogenic myxoma of mandible extending from symphysis to the left condylar neck. The hemimandibulectomy defect was restored with free fibular flap. Three months after 1st surgery, the transplant received five $IMZ^{(R)}$ implants. The masticatory function was restored with the implant borne denture. The result including facial appearance was very satisfactory.

• Journal of Periodontal and Implant Science
• /
• v.53 no.3
• /
• pp.173-183
• /
• 2023

Purpose: Treatment for periodontitis has evolved over the years as new technologies have become available. Currently, lasers seem attractive as a treatment modality, but their effectiveness needs to be verified. The purpose of this project was to evaluate Laser Assisted New Attachment Procedure^® (LANAP^®) surgery as a single treatment modality. Methods: As part of a mandatory training program for periodontists and other dentists, 22 consecutive patients diagnosed with moderate to severe periodontitis (probing depth [PD] up to 11 mm) were treated with the LANAP^® surgical approach using a 1064-nm Nd:YAG laser as part of a multi-step protocol. Following single-session active therapy, they were entered into a maintenance program. Their clinical status was re-evaluated at 12-18 months following surgery. Results: All 22 patients completed the 12- to 18-month follow-up. PD, clinical attachment level, and furcation (FURC) showed substantial improvement. Recession was minimal (mean, 0.1 mm), while 93.5% of PD measurements were 3 mm or less at re-evaluation. Furthermore, 40% of grade 2 FURC closed clinically. Conclusions: Within the limits of this case series, LANAP^® was found to be an effective, minimally invasive, laser surgical therapy for moderate to advanced periodontitis.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.33 no.2
• /
• pp.103-111
• /
• 2011

Purpose: Choukroun's platelet-rich-fibrin (PRF) is composed of platelets, white blood cells and fibrin matrix. It does not induce enough bone formation by itself but it can improve bone formation with calcium. Silk fibroin does not cause inflammatory reactions because it is bio-compatible and degradable. The purpose of this study was to exam the bone formation when a combination of Choukroun's PRF and silk fibroin was used. Methods: In this study, cell reactions to silk powder with differing molecular weights was first tested to select the appropriate silk powder. Then we applied these bone graft materials on defects of skull and in a peri-implant bony defect model in New Zealand rabbits. The results between the experimental and control s (non-grafted) group were analyzed. Results: The small sized silk fibroin powder showed increased cellular proliferation for bone-regeneration. There was no statistically significant difference between the experimental group and the control group at 6 weeks, but more new bone formation was observed in the combination graft group at 12 weeks (P<0.05). And in the dental implant model, the combination bone graft group showed much improved torque test results, which was statistically significant. Histomorphometric analysis showed more regenerated cortical bone and a higher mean bone to implant in the experimental group. Both were statistically significant. Conclusion: The combination graft of Choukroun's platelet-rich-fibrin (PRF) and silk fibroin powder can successfully restore the bony defects in a skull defected model and a peri-implant bony defects model.

• Journal of the Korean Academy of Esthetic Dentistry
• /
• v.32 no.2
• /
• pp.54-68
• /
• 2023

Treatment planning of edentulous patient with digital method is materialized by designing the surgical guide. When designing the surgical guide, we first implement the shape of the final prosthesis in the virtual space and then materialize the implantation plan based on this. However, it is challenging to make surgical guides for edentulous patients as their lack of both the reference for the arrangement of teeth and interocclusal relationship makes it hard to envision the shape of the final prosthesis. If there exists good partial or complete dentures or residual teeth, its teeth arrangement can be used as a reference for the virtual final prosthesis and the subsequent surgical guide. If such a reference is absent or unsatisfactory, a process of manufacturing a complete denture for diagnostic purposes and verifying it on patient's mouth is necessary and use it as a new reference for the virtual final prosthesis. But even if a surgical guide is produced through the reference from the thorough reflection of the virtual final prosthesis, when we use it in the surgical field, the intraoral condition of the patient may make the implants deviated from planned in the surgical guide. In the worst case, if the positioning of the surgical guide on the mouth is incorrect, it can lead to a catastrophic error that displaces all the implant, in which case the guided surgery would be much worse than the non-guided one. In this article, we will discuss how to obtain references of tooth arrangements in a timely manner and align or register them into a unified coordinate system in digital space, and also introduce how to transfer such an implantation plan from the virtual world into the patient's mouth of real world with minimum error. And lastly, I would like to express my opinion on the establishment of a rational and systematic protocol of guided surgery of the edentulous patients.

• Archives of Plastic Surgery
• /
• v.49 no.6
• /
• pp.729-739
• /
• 2022

Cranioplasties are common procedures in plastic surgery. The use of tissue expansion (TE) in staged cranioplasties is less common. We present two cases of cranioplasties with TE and systematically review literature describing the use of TE in staged cranioplasties and postoperative outcomes. A systematic review was performed by querying multiple databases. Eligible articles include published case series, retrospective reviews, and systematic reviews that described use of TE for staged bony cranioplasty. Data regarding study size, patient demographics, preoperative characteristics, staged procedure characteristics, and postoperative outcomes were collected. Of 755 identified publications, 26 met inclusion criteria. 85 patients underwent a staged cranioplasty with TE. Average defect size was 122 cm², and 30.9% of patients received a previous reconstruction. Average expansion period was 14.2 weeks. The most common soft tissue closures were performed with skin expansion only (75.3%), free/pedicled flap (20.1%), and skin graft (4.7%). The mean postoperative follow-up time was 23.9 months. Overall infection and local complication rates were 3.53 and 9.41%, respectively. The most common complications were cerebrospinal fluid leak (7.1%), hematoma (7.1%), implant exposure (3.5%), and infection (3.5%). Factors associated with higher complication rates include the following: use of alloplastic calvarial implants and defects of congenital etiology (p = 0.023 and 0.035, respectively). This is the first comprehensive review to describe current practices and outcomes in staged cranioplasty with TE. Adequate soft tissue coverage contributes to successful cranioplasties and TE can play a safe and effective role in selected cases.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.42
• /
• pp.10.1-10.9
• /
• 2020

Background: The aim of this study was to evaluate the long-term clinical stability of implants with acid-etched surfaces sandblasted with alumina using retrospective analyses of the survival rate, success rate, primary and secondary stability, complications, and marginal bone loss of the implants. Methods: Patients who had implants placed (TS III SA, SS II SA, SS III SA, and U III SA) with SA surfaces from Osstem (Osstem Implant Co., Busan, Korea) at the Seoul National University Bundang Hospital, from January 2008 to December 2010 were selected for the study. Patients' medical records and radiographs (panorama, periapical view) were retrospectively analyzed to investigate sex, age, location of implantation, diameter, and length of the implants, initial and secondary stability, presence of bone grafting, types of bone grafting and membranes, early and delayed complications, marginal bone loss, and implant survival rate. Results: Ninety-six implants were placed in 45 patients. Five implants were removed during the follow-up period for a total survival rate of 94.8%. There were 14 cases of complications, including 6 cases of early complications and 8 cases of delayed complications. All five implants that failed to survive were included in the early complications. The survival of implants was significantly associated with the occurrence of complications and the absorption of bone greater than 1 mm within 1 year after prosthetic completion. In addition, the absorption of bone greater than 1 mm within 1 year after prosthetic completion was significantly associated with the occurrence of complications, primary stability, and implant placement method. Five cases that failed to survive were all included in the early complications criteria such as infection, failure of initial osseointegration, and early exposure of the fixture. Conclusions: Of the 96 cases, 5 implants failed resulting in a 94.8% survival rate. The failed implants were all cases of early complications such as infection, failure of initial osseointegration, and early exposure of the fixtures. Periimplantitis was mostly addressed through conservative and/or surgical treatment and resulted in very low prosthetic complications. Therefore, if preventive measures are taken to minimize initial complications, the results can be very stable.

• The korean journal of orthodontics
• /
• v.47 no.5
• /
• pp.298-305
• /
• 2017

Objective: This paper describes changes in the characteristics of patients seeking orthodontic treatment over the past decade and the treatment they received, to identify any seasonal variations or trends. Methods: This single-center retrospective cohort study included all patients who presented to Seoul National University Dental Hospital for orthodontic diagnosis and treatment between January 1, 2005 and December 31, 2015. The study analyzed a set of heterogeneous variables grouped into the following categories: demographic (age, gender, and address), clinical (Angle Classification, anomaly, mode of orthodontic treatment, removable appliances for Phase 1 treatment, fixed appliances for Phase 2 treatment, orthognathic surgery, extraction, mini-plate, mini-implant, and patient transfer) and time-related variables (date of first visit and orthodontic treatment time). Time series analysis was applied to each variable. Results: The sample included 14,510 patients with a median age of 19.5 years. The number of patients and their ages demonstrated a clear seasonal variation, which peaked in the summer and winter. Increasing trends were observed for the proportion of male patients, use of non-extraction treatment modality, use of ceramic brackets, patients from provinces outside the Seoul region at large, patients transferred from private practitioners, and patients who underwent orthognathic surgery performed by university surgeons. Decreasing trends included the use of metal brackets and orthodontic treatment time. Conclusions: Time series analysis revealed a seasonal variation in some characteristics, and several variables showed changing trends over the past decade.

• Journal of Periodontal and Implant Science
• /
• v.36 no.1
• /
• pp.265-272
• /
• 2006

Dental plaque, a biofilm consisting of more than 500 different bacterial species, is an etiological agent of human periodontal disease, It is therefore important to characterize interactions among periodontopathic microorganisms in order to understand the microbial pathogenesis of periodontal disease. Previous data have suggested a synergistic effect of tow major periodontal pathogens Porphyromonas gingivalis and Tannerella forsythia in the periodontal lesion. In the present study, to better understand interaction between P. gingivalis and T. forsythia, the coaggregation activity between these bacteria was characterized. The coaggregation activity was observed by a direct visual assay by mixing equal amount (1 ${\times}$ $10^9$)of T. forsythia and P. gingivaJis cells. It was found that the first aggregates began to appear after 5-10 min, and that the large aggregates completely settled within 1 h. Electron and epifluorescence microscopic studies confirmed cell-cell contact between two bacteria. The heat treatment of P. gingivalis completely blocked the activity, suggesting an involvement of a heat-labile component of P. gingivalis in the interaction. On the other hand, heat treatment of T. forsythia significantly increased the coaggregation activity; the aggregates began to appear immediately. The coaggregation activity was inhibited by addition of protease, however carbohydrates did not inhibit the activity, suggesting that coaggregation is a protein-protein interaction. The results of this study suggest that coaggregation between P. gingivalis and T. forsythia is a result of cell-cell physical contact, and that coaggregation is mediated by a heat-labile component of P. gingivalis and T. forsythia component that can be activated on heat treatment.