• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.4
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• pp.321-328
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• 2017

Treatment options for edentulous patients are complete denture and implant prosthesis. A two implant-retained overdenture can be considered the first treatment in the edentulous mandible, but there is no clear consensus of treatment for edentulous maxilla. Implant-retention/support overdenture shows better retention and stability than complete denture and is less expensive and more esthetic than implant-supported fixed prosthesis. CM $LOC^{(R)}$ $Pekkton^{(R)}$ attachment is a solitary type attachment and evaluated to have excellent abrasion resistance and retention with a female part made of poly-ether-ketone-ketone. Meanwhile, SR Ivocap system is injection molding method and discussed to show few changes in the vertical dimension of denture and have excellent fracture resistance. In this case, we restored maxillary arch with a four implant-retained overdenture using CM $LOC^{(R)}$ $Pekkton^{(R)}$ and SR Ivocap system, and mandibular arch with a removable partial denture. Through this procedure, satisfactory outcomes were achieved both in functional and esthetic aspects.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.12
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• pp.105-112
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• 2020

The increase in the edentulous jaw which occurs in the aged population has led to personal dental health concerns. In the case of dental implant surgery, the duration of a patient's recovery depends on the surgical plan and their physicical ability. A device may be required to assist a physician in controlling vibration reduction of free-hand drilling and prescribing a good treatment plan that is suitable for the patient's condition. In this work, an artificial tooth-root implant assistant manipulator was studied. The structure and the vibration analysis of the dynamic restraint manipulator that is for drilling the alveolar bone in the mandible bone were performed, and the structural stability was analyzed. Further, a virtual prototype of an artificial tooth-root implant assisted manipulator was fabricated and tested. Hence, the state of the Remote Center of Motion (RCM) point and the driving state of the manipulator were confirmed. Furthermore, the drilling experiments were performed by using materials similar to a human jawbone in order to evaluate the performance of the drilling process that is operated using the assistant manipulator.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.2
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• pp.250-262
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• 2007

Statement of problem: It was reported high success rate of implant-supported fixed prostheses using with $5{\sim}6$ implants on anterior mandible. Recently, immediate loading protocol was focused to overcome disadvantages of classic 2-stage delayed loading protocol. Purpose: This clinical study was to evaluate stability changes with time of immediately loaded and delayed loaded implants in edentulous mandible and to compare stability changes with time according to implantation sites. Materials and methods: Five or six implants were placed on anterior mandible depending on the arch shape. The immediately loading group was consisted of 8 patients received their prostheses within $24{\sim}48$ hours after implantation. The delayed loading group was consisted of 8 patients received their definitive prostheses following classical prosthetic procedures after a healing period of 3 months. All patients were recalled every 6 months for check-up. The evaluations of radiographic examination, ISQ value measurement and recording of complication were done. To evaluate marginal bone level, intraoral periapical radiographs were taken with long cone paralleling technique. At every evaluation recall, all prostheses were removed and ISQ values were measured with OsstellTM on individual implants. Results: 1. None of implants was failed. All implants showed stable marginal bone levels and ISQ values. 2. Marginal bone level changes with time showed statistically significant difference between immediately loading group and delayed loading group (P<0.001). 3. ISQ value changes with time did not show statistically significant difference between immediately loading group and delayed loading group (P=0.079). ISQ value decreased with time in both groups, however, all implants showed stable ISQ value at 30 months-recall evaluation. 4. Marginal bone level changes with time did not show statistically significant differences among implantation sites (P=0.604). 5. ISQ value changes with time showed statistically significant differences among implantation sites (P=0.047). ISQ values of most posterior implants decreased with time comparing to other implants. Conclusion: Although the marginal bone level of the terminal abutment didn't different with the other implants, ISQ value of the terminal abutment was lower than that of the other implants. Therefore, further clinical evaluation would be needed in this point of view.

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.3
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• pp.243-253
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• 2009

This report described a technique utilizing a computer-aided design (CAD) /computer-aided machining (CAM) - guided surgical implant placement and prefabricated fixed complete denture for an immediately loaded restoration. A patient with an edentulous maxilla and mandible received 6 implants in maxilla and 6 implants in the mandible using CAD/CAM surgical templates. Prefabricated provisional maxillary and mandibular implant supported fixed prostheses were connected immediately after implant installation. Provisional prostheses were evaluated for aesthetics, function during 6 months. Definitive prostheses were fabricated.

• Imaging Science in Dentistry
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• v.38 no.1
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• pp.1-5
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• 2008

Purpose: The primary aims of this retrospective study were to compare subjective bone quality and bone quality based on the Hounsfield scale in different segments of the edentulous jaw, and to establish quantitative and objective assessment of the bone quality. Materials and Methods: Twenty eight randomly selected cone-beam computed tomographic (CBCT) scans were analyzed. For evaluation one hundred and twelve edentulous areas were selected. Implant recipient sites were evaluated visually for Lekholm and Zarb classification. The same sites were subsequently evaluated digitally using the Hounsfield scale with Vimplant$2.0^{TM}$, and the results were correlated with visual classification. Data was subject for statistical analysis in order to determine correlation between recorded HU and the regions of the mouth with the Kruskal-Wallis test. Results: The highest unit/mean density value (311 HU) was found in the anterior mandible, followed by 259 HU for the posterior mandible, 216 HU for the anterior maxilla, and 127 HU for the posterior maxilla. These results demonstrate a strong correlation for HU depending on the region of the mouth (p<0.001). The relationship between HU and type 4 bone was found to be significant (r=0.74). Conclusion: Knowledge of the Hounsfield value as a quantitative measurement of bone density can be helpful as a diagnostic tool by using $CBMercuRa6^{TM}$ with $Vimplant^{TM}$ software.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.5
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• pp.633-643
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• 2007

Statement of problem: Recently there are on an increasing trend of using implants-especially in edentulous mandible of severly alveolar bone recessed. Purpose: The aim of this study was to analyze the displacement and stress distribution of various mandibular implant-retained overdenture models supported by two implants in interforaminal region under the occlusion scheme load. Material and method: FEA models were made by the 3D scanning of the edentulous mandibular dentiform. The three models were named as Model M1, M2, and M3 accord ing to the position of implants: M1, Lt. incisor area, M2, Canine area, and M3, 1st Premolar area. Inter-implant angulation model was named as M4. Conventional complete denture was named M5 and used as a control group. Ball implant and Gold matrice were used as a retentive anchors. The occlusion type loads were applied horizontally over each tooth. Results: 1. In mandibular implant retained overdenture Canine Protected Occlusion type load resulted in higher levels of stress to the implants and female matrices than other types of loads. 2. The overdenture model M1, with implants in lateral incisor areas resulted in lower stress concentration to the implants and female matrices than other models. 3. In mandibular implant retained overdenture the stresses of the implant and female matrice were lower in mesially inclined implant than these of parallel installed implant. Conclusion: Lateral incisor areas could be the best site for the implants in mandibular implant-retained overdenture. The mandibular implant retained overdenture models mentioned above showed to the lowest stress to the implants and female matrices.

• Journal of Dental Rehabilitation and Applied Science
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• v.30 no.2
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• pp.176-183
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• 2014

Severely absorbed edentulous ridge cannot bear mechanical stress, causes undesired transformation of oral environment and makes patients difficult to adapt to dentures. Nowadays implant overdenture can be a treatment of choice in order to relieve patients' discomfort and improve stability and retention of the denture. Placement of implant on maxilla is difficult because of its bone quality and anatomic structure. It also has wide supportive tissue and convenience of border sealing, which provides sufficient support and stabilization with conventional complete denture. Mandible, on the other hand, is difficult to obtain sufficient support, retention and stabilization with conventional complete denture. Therefore, implant overdenture is recommended on mandible. Locator attachment has been improved for convenience of use and male parts of various retention enabled it to replace ball type attachment clinically. In this study, we restored maxillary arch with conventional denture, and mandibular arch with implant and tissue-supported overdenture and Locator attachment system.

• Journal of Dental Rehabilitation and Applied Science
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• v.18 no.4
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• pp.251-276
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• 2002

The purpose of this study was to compare and analyze the stress distribution and displacement of the fully bone anchored bridge and implant-supported overdenture in edentulous mandible on certain conditions such as number of implants, different design of superstructure. Three dimensional analysis was used and nine kinds of models designed for this study. FEM models were created using commercial software[$Rhinoceros^{(R)}$ (Ver. 1.0 Robert McNeel & Associates, USA)], and analyze using commercial software [Cosmos/$Works^{TM}$(Ver. 4.0 Structural Research & Analysis Corp., US A)]. A vertical load and $45^{\circ}$ oblique load of 17kgf were applied at the left 1st. molar. The results were as follows : (1) In the group of OVD, the displacement was reduced as increasing the number of fixture under vertical loading but there was no specific difference in Von Mises stress. Under oblique loading, the displacement was same at the vertical loading but Von Mises stress was reduced in order of OVD-3, OVD-4, OVD-2. But, bending moment reduced according to increasing the number of fixture. (2) In the group of FBAB, under vertical and oblique loading, the magnitude of Von Mises stress and displacement reduced according to increasing the number of fixtures. FBAB-4 and FBAB-5 showed similar score and distribution, but FBAB-6 showed lower value relatively. (3) In cantilever design, the maximum displacement reduced under vertical loading but increased under oblique loading. However, von mises stresses on fixtures increased under vertical and oblique loading. (4) In comparing OVD-group with FBAB-group, FBAB showed low magnitude of displacement in respect of oblique loading. However OVD-group was more stable in respect of stress distribution.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.1
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• pp.42-48
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• 2019

In the case of a patient with a small number of unilateral remaining teeth in the mandible, a restoration with conventional removable partial denture cannot provide sufficient retention and resistance. A harmful stress from the poor stability of denture on remaining teeth occurs due to alveolar bone resorption in edentulous area. Although implant fixed prosthesis can provide multiple benefits over conventional removable partial denture, there are limitations come from anatomic structures and costs. In this case, an implant-assisted removable partial denture (IARPD) with a couple of implants placed in strategic positions can be a treatment modality. The objective of this article is to present a case report of two patients showed satisfactory clinical outcomes during three-year follow-up period describing the fabrication and advantages of removable partial denture assisted by teeth and implants (IARPD) for a patient with a small number of unilateral remaining teeth in mandible using Locator as an implant attachment.

• Journal of Dental Rehabilitation and Applied Science
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• v.31 no.4
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• pp.349-357
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• 2015

Edentulous patients with a severely resorbed mandible or maxilla often experience problems with conventional dentures, such as insufficient stability and retention, together with a decrease in chewing ability. Because of the good prognosis of dental implants, these patients can be successfully treated with implant-retained or implant-supported prosthesis. Ideally, a maximum number of implants of maximum length are placed in appropriate surgically prepared sites that are surrounded by a maximum amount of bone of favorable quality. The implants are favorably aligned faciolingually and mesiodistally to enhance optimal prosthodontic design. This article describes the clinical problems and complications encountered when treating a consecutive number of edentulous patients with osseointegrated implant-supported prostheses.