• The Journal of Korean Academy of Prosthodontics
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• v.60 no.2
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• pp.187-194
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• 2022

The use of implants could improve the support, retention, and stability of removable prosthetic restoration for fully edentulous patients with severe alveolar bone resorption. When the prosthesis is manufactured without accurate diagnosis and evaluation, this may lead to unfavorable treatment result. The patient in this case had the treatment of implant overdentures at a private dental clinic, but visited the hospital for retreatment due to soft tissue pain and decreasing retention of existing dentures. The vertical dimension was raised compared to the existing dentures, and overdentures were manufactured using milled bars and additional attachments. The clinical results were satisfactory in the aspect of improved oral hygiene maintenance, function and esthetics.

• The Journal of Advanced Prosthodontics
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• v.4 no.4
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• pp.197-203
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• 2012

PURPOSE. The aim of this systematic review was to address treatment outcome according to attachment systems for mandibular implant overdentures in terms of implant survival rate, prosthetic maintenance and complications, and patient satisfaction. MATERIALS AND METHODS. A systematic literature search was conducted using PubMed and hand searching of relevant journals considering inclusion and exclusion criteria. Clinical trial studies on mandibular implant overdentures until August, 2010 were selected if more than one type of overdenture attachment was reported. Twenty four studies from 1098 studies were finally included and the data on implant survival rate, prosthetic maintenance and complications, patient satisfaction were analyzed relative to attachment systems. RESULTS. Four studies presented implant survival rates (95.8 - 97.5% for bar, 96.2 - 100% for ball, 91.7% for magnet) according to attachment system. Ten other studies presented an implant survival rate ranging from 93.3% to 100% without respect to the attachment groups. Common prosthetic maintenance and complications were replacement of an assay for magnet attachments, and activation of a matrix or clip for ball or bar attachments. Prosthetic maintenance and complications most commonly occurred in the magnet groups. Conflicting findings were found on the rate of prosthetic maintenance and complications comparing ball and bar attachments. Most studies showed no significant differences in patient satisfaction depending upon attachment systems. CONCLUSION. The implant survival rate of mandibular overdentures seemed to be high regardless attachment systems. The prosthetic maintenance and complications may be influenced by attachment systems. However patient satisfaction may be independent of the attachment system.

• The Journal of Korean Academy of Prosthodontics
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• v.54 no.2
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• pp.146-151
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• 2016

In patients with fully edentulous maxilla, fabrication of implant-supported overdenture can be a viable treatment option, when a minimum of six implants were strategically placed. Among several attachment systems used for implant-supported overdentures, milled-bars prevent rotational movement of denture, thus showing great stability, and have the advantage of splinting multiple implants with each other. In this case report, a milled-bar supported overdenture was fabricated for a patient suffering from condition of fully edentulous maxilla with severe ridge resorption in the anterior residual ridge. Seven implants composed of three different systems were effectively utilized by CAD/CAM customized abutment and cement-retained milled bar.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.1
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• pp.55-62
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• 2021

The mandible has a smaller support area than the maxilla, and in particular, in patients with generalized alveolar bone resorption, the stability of the denture and the masticatory efficiency are significantly low in the case of conventional complete denture, due to the movement of the tongue and mandible. In these patients, implant overdenture is evaluated as a highly predictable treatment method with high retention and stability, and excellent pronunciation and masticatory force. In this clinical case, patient had an edentulous maxilla and generalized alveolar bone resorption in mandible. Therefore, complete denture was placed in the maxilla and implant overdenture using milled bar attachment on 4 implants was placed in the mandible. During the 12-year follow-up period, changes in periodontal tissue and denture around the implants were periodically managed and observed.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.4
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• pp.412-419
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• 2022

For treatment of partially edentulous patients, a treatment using implant is widely used. Treatment method using implant are implant fixed prostheses and removable partial dentures, and for patients with severe bone resorption, removable implant overdenture with the effects of aesthetic and reducing cost can be used as treatment options. Specially, prosthesis with milled-bar and attachment has the effect of being splinted between implant fixtures, higher retention and stability than conventional removable partial denture. And it has the effect of improvement of aesthetic through lip support by denture base. In this case, the patient with severe alveolar bone resorption and partial edentulous maxilla and mandible was treated by implant-assisted removable partial denture using Milled-bar and ADD-TOC attachment. The esthetic was improved by removing the clasp because of effects of additional retention by using the attachment, and reducing palatal coverage of implant-assisted removable partial denture. The clinical results were satisfactory on the aspect of aesthetic and masticatory function.

• 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 Advanced Prosthodontics
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• v.6 no.1
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• pp.66-70
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• 2014

A dynamic impression is a functional impression that records the functional movement of the patient's own muscle and muscle attachment. This process reduces the number of random factors. This article describes a method for making a special tray using a dynamic impression concept that was made from provisional dentures used for implant healing. The individual tray is used to make a wash-impression to record the features of the mucosa in detail. The main advantage of this technique is that it provides a functional relationship of the implant components to the supporting tissues without overextension because provisional denture had been used for 2 months and the border length of individual tray was nearly the same as that of provisional denture. The delivery of the prosthesis constructed using this impression technique is time-saving because there is no need for border molding and there are fewer post-insertion appliance adjustments.

• The Journal of Advanced Prosthodontics
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• v.7 no.3
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• pp.191-198
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• 2015

PURPOSE. The purpose of this study was to compare the coronal bone level and patient satisfaction in 1-implant and 2-implant assisted mandibular overdentures. MATERIALS AND METHODS. Twenty patients who had maladaptive mandibular dentures were treated in this study. Patients were randomly divided into two groups. The first group received 1 implant (Simple line II, Implantium, South Korea) in their mandibular midline and the second group received 2 implants in their B and D regions (according to Misch's category). If the primary stability of each implant was at least 60 ISQ, ball attachment was placed and denture relined with soft liner. After 6 weeks, retentive cap incorporated with hard acrylic resin. In the 6 and 12 months recalls, periapical digital radiograph were made and visual analogue scale questionnaires were used to record patient satisfaction. The Friedman test was done for comparing the presurgical and postsurgical parameters in each group and the U-Mann Whitney test (P<.05) was done for comparison of post-treatment results between the two groups. RESULTS. All implants achieved sufficient primary stability to be immediately loaded. Patient satisfaction was high, and there were no significant differences between two groups (P>.05). In addition, mean marginal bone loss was $0.6{\pm}0.67$ mm in the first group and $0.6{\pm}0.51$ mm in the second group, after 12 month. Mean marginal bone loss showed no significant differences between two groups. CONCLUSION. This preliminary one-year result indicated that mandibular overdentures anchored to a single implant can be a safe and cost-effective method as a starting step for implant-overdenture treatment.

• The Journal of Advanced Prosthodontics
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• v.13 no.1
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• pp.55-64
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• 2021

PURPOSE. To investigate the biomechanical effect of marginal bone resorption (MBR) on the mandibular mini implant (MI)-retained overdenture (MI-OD) on the edentulous model. MATERIALS AND METHODS. The experimental mandibular edentulous model was modified from a commercial model with 2 mm thick artificial soft tissue under denture base. Two MIs (Φ2.6 mm × 10 mm) were bilaterally placed between the lateral incisor and the canine area and attached with magnetic attachments. Three groups were set up as follows: 1) alveolar bone around the MI without MBR (normal group), 2) with MBR to 1/2 the length of the implant (resorption group), and 3) complete denture (CD) without MI (CD group). Strain around the MI, pressure near the first molar area, and displacement of denture were simultaneously measured, loading up to 50 N under bilateral/unilateral loading. Statistical analysis was performed using independent-samples t test and one-way ANOVA (α=.05). RESULTS. The strain around the MI with MBR was approximately 1.5 times higher than that without MBR. The pressure in CD was higher than in MI-ODs (P<.05), while there was no statistical difference between the normal and resorption group (P>.05). Similarly, the CD demonstrated a greater displacement of the denture base than did the MI-ODs during bilateral and unilateral loadings (P<.05). CONCLUSION. The strain around the MI with MBR was approximately 1.5 times higher than that without MBR. The pressure on posterior alveolar ridge and denture displacement of MI-ODs significantly decreased compared to CDs, even when MBR occurs. Bilateral balanced occlusion was recommended for MI-ODs, especially when MBR occurred.

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.2
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• pp.150-156
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• 2015

As dental implant treatment becomes popular for both partial and complete edentulous patients, old people with complex systemic diseases also tend to prefer implant-assisted-overdenture or implant-supported-fixed prostheses to conventional complete denture. In this case, 77-year-old female who was on medication for hypertension and osteoporosis and paralyzed on right side due to stroke visited for implant-assisted-overdenture on lower jaw. After oral and radiographic examination, root-assisted magnet overdenture on upper jaw and implant-assisted magnet overdenture on lower jaw are planned. Consequently, overdentures using self-adjusting magnetic attachment(SA) system on both jaws resulted in recovering satisfying function and retention, which is enable to insert and remove with only one hand.