• The Journal of Korean Academy of Prosthodontics
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• v.53 no.1
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• pp.1-8
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• 2015

Purpose: The purpose of this prospective study was to compare the satisfaction levels of the patients worn implant supported mandibular overdentures and conventional complete dentures. Materials and methods: Full edentulous patients (n=40) who were planned to do implant supported mandibular overdentures, aged 51 to 82 years, were enrolled in this study. All subjects rated their satisfaction levels (mastication, pronunciation, esthetics, pain, and general satisfaction) of their original conventional dentures prior to treatment and their new overdentures 1 week and 12 weeks after the delivery on 10 cm visual analogue scales. Repeated-measures ANOVA was performed to compare the satisfaction level of each three period (P<.05). Results: The mean satisfaction levels of the implant supported overdentures after 1 week and 12 weeks of delivery were significantly higher than those of the conventional complete dentures in all scoring parameters (P<.05). After 12 weeks of overdenture delivery, the increase of the satisfaction levels in mastication, pronunciation, and pain and the decrease in esthetics and general satisfaction were observed in comparison with those after 1 week of delivery, however, no significant difference was found between the satisfaction levels of 1 week and 12 weeks after delivery. Conclusion: An implant supported overdenture might be one of the effective ways to give more satisfaction to patients who were not gratified with a conventional denture and eventually to improve their quality of life.

• 대한치과보철학회:학술대회논문집
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• 2001.11a
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• pp.72-72
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• 2001

• The Journal of Advanced Prosthodontics
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• v.8 no.2
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• pp.85-93
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• 2016

PURPOSE. The purpose of this study was to determine the effect of anchorage systems and palatal coverage of denture base on load transfer in maxillary implant-retained overdenture. MATERIALS AND METHODS. Maxillary implant-retained overdentures with 4 implants placed in the anterior region of edentulous maxilla were converted into a 3-D numerical model, and stress distribution patterns in implant supporting bone in the case of unilateral vertical loading on maxillary right first molar were compared with each other depending on various types of anchorage system and palatal coverage extent of denture base using three-dimensional finite element analysis. RESULTS. In all experimental models, the highest stress was concentrated on the most distal implant and implant supporting bone on loaded side. The stress at the most distal implant-supporting bone was concentrated on the cortical bone. In all anchorage system without palatal coverage of denture base, higher stresses were concentrated on the most distal implant and implant supporting bone on loaded side. CONCLUSION. It could be suggested that when making maxillary implant retained overdenture, using Hader bar instead of milled bar and full palatal coverage rather than partial palatal coverage are more beneficial in distributing the stress that is applied on implant supporting bone.

• The Journal of Advanced Prosthodontics
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• v.7 no.4
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• pp.329-337
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• 2015

PURPOSE. This retrospective study aims at the evaluation of implant-supported overdentures (IODs) supported by ceramo-galvanic double crowns (CGDCs: zirconia primary crowns + galvano-formed secondary crown). MATERIALS AND METHODS. In a private practice, 14 patients were restored with 18 IODs (mandible: 11, maxilla: 7) retained by CGDCs on 4 - 8 implants and annually evaluated for technical and/or biological failures/complications. RESULTS. One of the 86 inserted implants failed during the healing period (cumulative survival rate (CSR) implants: 98.8%). During the prosthetic functional period (mean: $5.9{\pm}2.2years$), 1 implant demonstrated an abutment fracture (CSR-abutments: 98.2%), and one case of peri-implantitis was detected. All IODs remained in function (CSR-denture: 100%). A total of 15 technical complications required interventions to maintain function (technical complication rate: 0.178 treatments/patients/year). CONCLUSION. Considering the small sample size, the use of CGDCs for the attachment of IODs is possible without an increased risk of technical complications. However, for a final evaluation, results from a larger cohort are required.

• The Journal of Advanced Prosthodontics
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• v.12 no.4
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• pp.239-249
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• 2020

PURPOSE. The purpose of this study was to investigate survival rates of the implants used in implant assisted removable partial dentures (IARPDs). MATERIALS AND METHODS. The study was conducted on 21 patients who were treated with IARPDs. The mean follow-up period for IARPD patients ranged from 12 to 185 months (mean 47.9 months). A total of 58 implants were used for IARPDs in two different modalities: 41 for surveyed crowns and 17 for overdentures. The survival of implants was determined by clinical and radiographic evaluations considering relevant factors: location, RPD classification, opposing dentition, splinting, and implant diameter. RESULTS. The survival rate of total 58 implants was 93.1%: 95.1% for implants supporting surveyed crowns and 88.2% for implants used in overdentures. Considering only the implants supporting surveyed crown, regular diameter implants showed a higher survival rate than narrow or wide diameter implants. CONCLUSION. The survival rate of the implants used in IARPDs was 93.1% (surveyed crown: 95.1%, overdenture: 88.2%).

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.4
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• pp.375-390
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• 2009

Statement of problem: Implant supported overdenture is accepted widely as a way to restore edentulous ridge providing better retention and support of dentures. Various types of attachment for overdenture have been developed. Purpose: The purpose of this study was to investigate the influence of attachment type in implant overdentures on the biomechanical stress distribution in the surrounding bone, prosthesis and interface between implant and bone. Material and methods: Finite element analysis method was used. Average CT image of mandibular body(Digital $Korea^{(R)}$, KISTI, Korea) was used to produce a mandibular model. Overdentures were placed instead of mandibular teeth and 2mm of mucosa was inserted between the overdenture and mandible. Two implants($USII^{(R)}$, Osstem, Korea) were placed at both cuspid area and 4 types of overdenture were fabricated ; ball and socket, Locator, magnet and bar type. Load was applied on the from second premolar to second molar tooth area. 6 times of finite element analyses were performed according to the direction of the force $90^{\circ}$, $45^{\circ}$, $0^{\circ}$ and unilateral or bilateral force applied. The stress at interface between implants and bone, and prosthesis and the bone around implants ware compared using von Mises stress. The results were explained with color coded graphs based on the equivalent stress to distinguish the force distribution pattern and the site of maximum stress concentration. Results: Unilateral loading showed that connection area between implant fixture and bar generated maximum stress in bar type overdentures. Bar type produced 100 Mpa which means the most among 4 types of attachments. Bilateral loading, however, showed that bar type was more stable than other implants(magnet, ball and socket). 26 Mpa of bar type was about a half of other types on overdenture under $90^{\circ}$ bilateral loading. Conclusions: In any directions of stress, bar type was proved to be the most vulnerable type in both implants and overdentures. Interface stress did not show any significant difference in stress distribution pattern.

• The Journal of Korean Academy of Prosthodontics
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• v.54 no.3
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• pp.267-272
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• 2016

This case report describes the treatment of two fully edentulous patients with mini-implant overdentures using different implant systems on narrow mandibular alveolar bone ridge. They were complaining about discomfort and pain wearing mandibular conventional complete dentures caused by insufficient retention. Each patient received four miniimplants in the interforaminal area of the mandible using the non-submerged flapless surgical approach. One-body type implant (Slimline, Dentium, Seoul, Korea) was used for a patient and loaded immediately after surgery. Metal housings of O-ring were attached by direct technique. For the other patient, two-piece type implant (LODI, Zest Anchors, Escondido, CA, USA) was used and impressions were made for attachment connection of the Locator's metal housings after 8 weeks of surgery. Within this case report, mandibular miniimplant overdentures using different implant systems showed improvement of patient satisfaction with favorable peri-implant tissue response 6 months after attachment connection. However, long-term follow-up is needed for further evaluation.

• The Journal of Korean Academy of Prosthodontics
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• v.29 no.1
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• pp.249-254
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• 1991

Two male patients of hereditary ectodermal dysplasia with oligodontia aged 12years and 10years 6months were recalled after 6 years and treated by reconstructing overdentures according to the growth. Patients were improved functionally and cosmetically. Periodic recall is reguired and denture should be reconstructed according ato their growth.

• Journal of Korean Dental Science
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• v.15 no.2
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• pp.152-161
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• 2022

Mandibular implant overdenture is a good treatment option for complete edentulous patients with restoring removable prosthesis. Mandibular implant overdenture with two implants and locator attachments is widely used. It is tissue-supported overdenture that is made with the concept of conventional complete denture fabrication. There are two patients who provided impressions by open mouth technique and closed mouth technique in each case. In both cases, mandibular implant overdentures were restored with functionally and aesthetically satisfying results.

• The Journal of Advanced Prosthodontics
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• v.9 no.3
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• pp.143-151
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• 2017

PURPOSE. The design of the attachment must provide an optimum stress distribution around the implant. In this study, for implant overdentures with a bar/clip attachment or a locator attachment, the stress transmitted to the implant in accordance with the change in the denture base length and the vertical pressure was measured and analyzed. MATERIALS AND METHODS. Test model was created with epoxy resin. The strain gauges made a tight contact with implant surfaces. A universal testing machine was used to exert a vertical pressure on the mandibular implant overdenture and the strain rate of the implants was measured. RESULTS. Means and standard deviations of the maximum micro-deformation rates were determined. 1) Locator attachment: The implants on the working side generally showed higher strain than those on the non-working side. Tensile force was observed on the mesial surface of the implant on the working side, and the compressive force was applied to the buccal surface and on the surfaces of the implant on the non-working side. 2) Bar/clip attachment: The implants on the both non-working and working sides showed high strain; all surfaces except the mesial surface of the implant on the non-working side showed a compressive force. CONCLUSION. To minimize the strain on implants in mandibular implant overdentures, the attachment of the implant should be carefully selected and the denture base should be extended as much as possible.