• 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.53 no.1
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• pp.58-65
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• 2015

For the rehabilitation of fully edentulous patients, implant-supported removable partial dentures can be considered as one of the treatment options with complete dentures or implant-supported overdentures. If removable partial dentures are used in combination with a small number of implants placed in strategically important positions, it can offer additional stability, retention and support through implants and reduce a burden of surgical procedures compared with fixed implant-supported prostheses with extensive implant placement. Moreover, the economical benefit can be expected as well. The purpose of this case report is to present a treatment in which an implant-supported removable partial denture was fabricated considering residual alveolar bone status and demands after teeth loss in a patient who had been using a distal extension removable partial denture for a long period of time. In anterior area, fixed prostheses were fabricated with implant placement and in posterior area, short implants provide only support for the removable partial denture. In addition, denture base and clasp were made of thermoplastic acrylic resin. Finally, functionally and aesthetically satisfying treatment results can be achieved.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.33 no.2
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• pp.158-165
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• 2011

A 73-year-old Korean female patient with a fully edentulous mandible was planned to have five implant fixtures installed in the anterior mandible for the fixed prosthesis. After 3-dimensional (3D) computed tomographic scanning was transferred to OnDemand3D$^{(R)}$ (Cybermed Co., Seoul, Korea) software program for the virtual planning, five fixtures of MK III Groovy RP implants of Branemark System$^{(R)}$ (Nobel Biocare AB Co., Goteborg, Sweden) were installed in the anterior mandible between both mental foramens using In2Guide$^{(R)}$ (CyberMed Co., Seoul, Korea) mucosa-supported surgical template with Quick Guide Kit$^{(R)}$ (Osstem Implant Co., Seoul, Korea) systems. Fixture installations were completed successfully without any complications, such as mental nerve injury, bony bleedings, fenestrations and other unexpected events. Postoperative computed tomographic scans were aligned and fused to the planned implant, then angular and linear deviations were compared with the planned virtual implants. The mean angular deviation between the planned and actual implant axes was $3.42{\pm}1.336^{\circ}$. The mean distance between the planned and actual implant at the neck area was $0.544{\pm}0.290$ mm horizontally and $0.118{\pm}0.079$ mm vertically. The average distance between the planned and actual implant at the apex area was $1.166{\pm}0.566$ mm horizontally and $0.14{\pm}0.091$ mm vertically. These results could be considered more precise and accurate than previous reports, and even our recent results. The entire procedures of this case are reported and reviewed.

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.4
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• pp.417-429
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• 2009

Since the introduction of the concept of osseointegration in dental implants, high long-term success rates have been achieved and accepted as viable option for the treatment of fully and partially edentulous patients. Although the use of domestic implants have increased dramatically, there are few studies on domestic implants with clinical and objective long-term data. 96 endosseous implants placed in 31 patients at Wonkwang University Sanbon Dental Hospital were examined to determine the effect of various factors on implant survival rate and marginal bone loss, through clinical and radiographic results. The design of endosseous implant used to this study is straight with the microthread.(GS II RBM Fixture) 1. 3 fixtures were lost, resulting in 96.9% cumulative survival rate. 2. Survival rate in fifties was significantly lower (93.6%) and no significant difference in marginal bone loss was found according to gender. 3. Survival rates were 95.6% in the maxillary molar area and 97.3% in the mandible molar area. 4. No significant difference in survival rate was found according to presence of bone grafts, type of prostheses, implant position, and length and diameter of implant. 5. A factor influencing marginal bone loss was presence of type of prostheses, while facters such a length, diameter of fixture and bone grafts had no statistically significant effect on crestal bone loss. This study indicates the amount of marginal bone loss around implant has maintained a relative stable during follow-up periods.

• Journal of Periodontal and Implant Science
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• v.32 no.3
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• pp.615-630
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• 2002

Various long-term studies have shown that titanium implants as abutments for different types of prostheses have become a predictable adjunct in the treatment of partially or fully edentulous patients. The continuous exposure of dental implants to the oral cavity with all its possible contaminants creates a problem. A lack of attachment, together with or caused by bacterial insult, may lead to peri-implantitis and eventual implant failure. Removal of plaque and calculus deposits from dental titanium implants with procedures and instruments originally made for cleaning natural teeth or roots may cause major alterations of the delicate titanium oxide layer. Therefore, the ultimate goal of a cleaning procedure should be to remove the contaminants and restore the elemental composition of the surface oxide without changing the surface topography and harming the surrounding tissues. Among many chemical and mechanical procedure, air-powder abrasive have been known to be most effective for cleaning and detoxification of implant surface. Most of published studies show that the dental laser may be useful in the treatment of pen-implantitis. $CO_2$ laser and Soft Diode laser were reported to kill bacteria of implant surface. The purpose of this study was to obtain clinical guide by application these laser to implant surface by means of Non-contact Surface profilometer and X-ray photoelectron spectroscopy(XPS) with respect to surface roughness and atomic composition. Experimental rough pure titanium cylinder models were fabricated. All of them was air-powder abraded for 1 minute and they were named control group. And then, the $CO_2$ laser treatment under dry, hydrogen peroxide and wet condition or the Soft Diode laser treatment under Toluidine blue O solution condition was performed on the each of the control models. The results were as follows: 1. Mean Surface roughness(Ra) of all experimental group was decreased than that of control group. But it wasn't statistically significant. 2. XPS analysis showed that in the all experimental group, titanium level were decreased, when compared with control group. 3. XPS analysis showed that the level of oxygen in the experimental group 1, 3($CO_2$ laser treatment under dry and wet condition) and 4(Soft Diode laser was used under toluidine blue O solution) were decreased, when compared with control group. 4. XPS analysis showed that the atomic composition of experimental group 2($CO_2$ laser treatment under hydrogen peroxide) was to be closest to that of control group than the other experimental group. From the result of this study, this may be concluded. Following air-powder abrasive treatment, the $CO_2$ laser in safe d-pulse mode and the Soft Diode laser used with photosensitizer would not change rough titanium surface roughness. Especially, $CO_2$ laser treatment under hydrogen peroxide gave the best results from elemental points of view, and can be used safely to treat peri-implantitis.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.5
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• pp.653-664
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• 2007

Statement of problem: The screw detorque value is a measure of the preload remaining in the screw just before detorquing. Purpose: This study evaluated the effect of different screw tightening sequences and tightening methods on detorque values for a well-fitting implant superstructure. Material and method: An implant superstructure that connected directly to four implants (Astra Tech) was fabricated on a fully edentulous mandibular acrylic resin model. Six well-fitting dental stone casts were made with a pickup impression of the superstructure from the acrylic resin model. To evaluate the effect of three screw tightening sequences (1-2-3-4, 2-4-3-1, and 2-3-1-4) and two tightening methods (2-step and 1-step) on the stability of screw joint, the detorque values for a well-fitting implant superstructure were measured twice after screw tightening using 20 Ncm. Detorque values were analyzed using multi-way analysis of variance and two-way analysis of variance at a .05 level of significance. Results: 1. The mean detorque values for three screw tightening sequences were 12.3 Ncm, 12.6 Ncm, and 12.0 Ncm, respectively. 2. The mean detorque values for two screw tightening methods were 12.0 Ncm, and 12.2 Ncm, respectively. 3. The mean of mimimum detorque values for three screw tightening sequences and for two tightening methods were 10.6 Ncm, 11.1 Ncm, 10.5 Ncm, and 9.8 Ncm, respectively. 4. No statistically significant differences among the variables of screw tightening sequence and tightening method were found (p>.05) for detorque values and for mimimum detorque values. Conclusion: Within the limitations of this study, the screw tightening sequence and tightening method did not have a significant effect on the detorque values for a well-fitting implant superstructure.

• The Journal of Korean Academy of Prosthodontics
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• v.55 no.1
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• pp.61-70
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• 2017

In this case, the impression surface of the existing denture was scanned and was inverted three-dimensionally to express the residual ridge form. Implant planning was performed on the superimposed data of the CT with the scanned image of the denture with radiopaque markers attached. At the day of surgery, customized abutments fabricated in accordance with the form of the gingival margin were linked with fixtures and temporary restorations were set. In the process of fabricating the final prosthesis after the osseointegration of implant fixture, the intraoral scan images at abutment level were merged with images of the abutments scanned and stored before implant surgery. By fabricating the final prosthesis with the abutments obtained by merging can increase the marginal fitness of the final prosthesis and simplify the clinical process.

• Journal of Periodontal and Implant Science
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• v.37 no.4
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• pp.825-838
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• 2007

Endosseous implants are used in the treatment of various types of tooth loss, and numerous long-term studies have demonstrated the excellent reliability of this method of treatment. However, the increase of implant failure are associated with inadequate quality and/or height of bone. At the end of the 1980s, Wide(>3.75mm) implants were initially used for managing these difficult bone situations. The recommended indications for its use included poor bone quality, inadequate bone height. immediate placement in fresh extraction sockets, and immediate replacement of failed implants. At the 2000s, wider implants(6.0mm and 6.5mm) were used in a few studies. Although good clinical outcomes have been reported in recent years, there is still a controversy on this topic. Therefore, the purpose of this study was to estimate the survival rate of wide implants($6.0{\sim}8.0mm$) in molar regions, evaluating the clinical outcome. In this study, 1135 RBM surfaced wide implants($Rescue^{TM}$, MEGAZEN Co., Korea/595 maxillary, 540 mandibular) were placed in 650 patients(403 male, 247 female/age mean: $51.2{\pm}11.1$ years, range 20 to 83 years). Of the total, 68.3% were used to treat fully or partially edentulous situations, including single-tooth losses and 31.7% were placed immediately after teeth extraction or removal of failed implants, of which all were in the molar regions. Implant diameter and length ranged from 6.0 to 8.0mm and from 5.0 to 10.0mm respectively. The implants were followed for up to 42 months (mean: $14.6{\pm}9.5$ months). Of 1135 placed implants, 58 implants were lost. Among them, 53 implants were lost within 12 months after implant placement. The survival rate was 93.6% in the maxilla and 96.3% in the mandible, yielding an overall survival rate of 94.9%, for up to 42 months. As the result of Cox regression model, prosthetic type, sinus graft, and patient gender have an statistical significance on the implant survival rate in this study. This study suggests that the use of wide implants($6.0{\sim}8.0mm$) would provide a predictable treatment alternative in posterior areas.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.1
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• pp.97-106
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• 2021

Dental implants should be placed at ideal sites for implant-supported restorations. For a patient with insufficient residual ridge, mouth preparation including surgical intervention can be indicated to establish a soft and hard tissue environment favorable for a definitive prosthesis. Prosthodontic design based on computer-guided surgery and computer-aided design-computer-aided manufacturing (CAD-CAM) provides a visual blueprint allowing a clinician to assess the necessity of such a surgical intervention beforehand. In this case, a definitive restoration was planned and made via a CAD-CAM system according to the patient's oral status before treatment, simulated surgical interventions and serial provisional restorations. Based on the planning, a guided template was made and the implants were installed with bone augmentation using the template. Customized abutments, the first and the second provisional restorations were designed and fabricated by CAD-CAM. The definitive restorations were digitally made following the shape of the second provisional prostheses, which were confirmed in the patient's mouth. The patient was satisfied with the masticatory, phonetic and aesthetic functions of these definitive prostheses.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.1
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• pp.79-87
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• 2021

The digital workflow of optical impressions by the intraoral scanner and CADCAM manufacture of dental prostheses is actively developing. The complex process of traditional impression taking, definite cast fabrication, wax pattern making, and casting has been shortened, and the number of patient's visits can also be reduced. Advances in intraoral scanner technology have increased the precision and accuracy of optical impression, and its indication is progressively widened toward the long span fixed dental prosthesis. This case report describes the long span implant case, and the operator fully utilized digital workflow such as computer-guided implant surgical template and CAD-CAM produced restoration after the digital impression. The provisional restoration and customized abutments were prepared with the optical impression taken on the same day of implant surgery. Moreover, the final prosthesis was fabricated with the digital scan while utilizing the same customized abutment from the provisional restoration. During the data acquisition step, stl data of customized abutments, previously scanned at the time of provisional restoration delivery, were imported and automatically aligned with digital impression data using an 'A.I. abutment matching algorithm' the intraoral scanner software. By using this algorithm, it was possible to obtain the subgingival margin without the gingival retraction or abutment removal. Using the digital intraoral scanner's advanced functions, the operator could shorten the total treatment time. So that both the patient and the clinician could experience convenient and effective treatment, and it was possible to manufacture a prosthesis with predictability.