• Journal of Technologic Dentistry
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• v.44 no.3
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• pp.67-75
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• 2022

Purpose: This study aimed to comparatively evaluate the stress distribution of bones surrounding the implant system to which both titanium and polyetheretherketone (PEEK) abutments are applied using a three-dimensional finite element analysis. Methods: The three-dimensional implant system was designed by the computer-aided design program (CATIA; Dassault Systemes). The discretization process for setting nodes and elements was conducted using the HyperMesh program (Altair), after finishing the design of each structure for the customized abutment implant system. The results of the stress analysis were drawn from the Abaqus program (Dassault Systèmes). This study applied 200 N of vertical load and 100 N of oblique load to the occlusal surface of a mandibular first molar. Results: Under external load application, the PEEK-modeled dental implant showed the highest von Mises stress (VMS). The lowest VMS was observed in the Ti-modeled abutment screws. In all groups, the VMS was observed in the crestal regions or necks of implants. Conclusion: The bones surrounding the implant system to which the PEEK abutment was applied, such as the cortical and trabecular bones, showed stress distribution similar to that of the titanium implant system. This finding suggests that the difference in the abutment materials had no effect on the stress distribution of the bones surrounding implants. However, the PEEK abutments require mechanical and physical properties improved for clinical application, and the clinical application is thought to be limited.

• The Journal of the Korean dental association
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• v.47 no.9
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• pp.585-595
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• 2009

Purpose : The aim of this study was to compare surgical complications between simple implant placement and implant placement combined with complicated surgical procedures. We also evaluated prosthetic complications according to the specific types of prosthesis. Material and Method : A retrospective analysis of dental chart of patients who was performed implant therapy during the period from June 2003 to December 2005 was carried out. This study was performed on 408 patients (208 male, 200 female). In addition, 1671 implants were performed. Based on their medical record and radiographs, the authors evaluated surgical and prosthetic complications, surgical procedures accompanied at the time of implant, risk factors of implant failure etc. Result : Surgical complications were developed on 358 implants(21.4% on total placed implants) and wound dehiscence was most prevalent complication. On maxillary posterior area, surgical complications developed more frequently on implants with major surgery and showed a significant difference. And complication rate of implants accompanied with GBR was higher than that of simple implants placement and also showed significant difference. The implant supported prosthesis showed no statistical difference in the occurrence of complications according to the types of prosthesis, and food retention was the most common post-prosthetic complication. Also we speculated that length and width of implant showed significant correlation to the failure of implant primary osseointegration. Conclusion : Based on the result, clinician should provide more careful maintenance for patients with implant placement accompanied by complicated surgical procedure. And periodic maintenance for the patient is requested for long-term survival of implant therapy.

• The Journal of Advanced Prosthodontics
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• v.7 no.5
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• pp.380-385
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• 2015

PURPOSE. The aim of this study was to determine the frequency of significant panoramic radiographic findings and eventual treatment requirements before conventional or implant supported prosthetic treatment in asymptomatic edentulous patients. MATERIALS AND METHODS. A total of 743 asymptomatic edentulous patients were retrospectively evaluated using a digital panoramic system. We analyzed the radiographic findings, including impacted teeth, retained root fragments, foreign bodies, severe atrophy of the posterior maxillary alveolar bone, mucous retention cysts, soft tissue calcifications and radiopaque-radiolucent conditions. RESULTS. Four-hundred-eighty-seven (65.6%) patients had no radiographic finding. A total of 331 radiographic findings were detected in 256 (34%) patients. In 52.9% (n=175) of these conditions, surgical treatment was required before application of implant-supported fixed prosthesis. However, before application of conventional removable prosthesis surgical treatment was required for 6% (n=20) of these conditions. CONCLUSION. The edentulous patients who will have implant placement for implant-supported fixed prosthesis can frequently require additional surgical procedures to eliminate pathological conditions.

• The Journal of Korean Academy of Prosthodontics
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• v.51 no.3
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• pp.221-225
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• 2013

Proper management of provisional prosthesis is key to success in prosthodontics. Provisional restoration on maxillary anterior missing area frequently come across a incident of falling off especially in patients with long span pontics and oval arch shape. This is because maxillary anterior teeth are more exposed to horizontal force than the posterior teeth and additional anterior cantilever effect will negatively affect to the retention of provisional prosthesis. Beside that maxillary anterior provisional prosthesis should provide proper incisal guidance during the mandibular functional movements. However occlusal contacts on the prosthesis in maximum intercuspal position are located on opposite side of fulcrum line of prosthesis which will cause removing force against the provisional prosthesis. This case report present that provisional implant prevent pre-described harmful effect on maxillary anterior fixed provisional prosthesis and provide comfort and satisfactory result during post-extraction healing period.

• Journal of Dental Rehabilitation and Applied Science
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• v.36 no.3
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• pp.176-182
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• 2020

Purpose: To evaluate the effects of load direction, number of implants, and alignment of implant position on stress distribution in implant, prosthesis, and bone tissue. Materials and Methods: Four 3D models were made to simulate posterior mandible bone block: two implants and 3-unit fixed dental prosthesis (FDP) with a pontic in the center (model M1), two implants and 3-unit FDP with a cantilever pontic at one end (model M2), FDP supported by three implants with straight line placement (model M3) and FDP supported by three implants with staggered implant configuration (model M4). The applied force was 120 N axially or 120 N obliquely. Results: Peak von Mises stresses caused by oblique occlusal force were 3.4 to 5.1 times higher in the implant and 3.5 to 8.3 times higher in the alveolar bone than those stresses caused by axial occlusal force. In model M2, the connector area of the distal cantilever in the prosthesis generated the highest von Mises stresses among all models. With the design of a large number of implants, low stresses were generated. When three implants were placed, there were no significant differences in the magnitude of stress between staggered arrangement and straight arrangement. Conclusion: The effect of staggering alignment on implant stress was negligible. However, the number of implants had a significant effect on stress magnitude.

• The Journal of Korean Academy of Prosthodontics
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• v.58 no.3
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• pp.239-243
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• 2020

When the marginal fit of fixed dental prosthesis decreases, biological and technical complications, such as plaque accumulation, periodontal disease, hypersensitivity, components fracture, cement loss, can happen. The complications affect the long-term success and survival of prostheses. This case report describes a clinical procedure to minimize the marginal gap of implant-supported screw-and-cement retained prosthesis by removing prosthesis-abutment complex and burnishing the interface area. The marginal gap was measured before and after the burnishing using a stereomicroscope and compared. This technique improves the marginal fit, thereby contributing the longevity of the prosthesis.

• Journal of Periodontal and Implant Science
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• v.45 no.6
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• pp.210-215
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• 2015

Purpose: The aim of this retrospective study was to investigate the cumulative success rate, the implant survival rate, and the occurrence of biological complications in implants supporting full-arch immediately loaded rehabilitations supported by upright and tilted implants. Methods: The clinical records and periapical radiographs of patients who attended follow-up visits were collected, and information was recorded regarding marginal bone loss resorption, the occurrence of peri-implant infectious diseases, and the implant survival rate. Implants were classified as successful or not successful according to two distinct classifications for implant success. Results: A total of 53 maxillary and mandibular restorations including 212 implants were analysed, of which 56 implants were studied over the full five-year follow-up period. After five years, the cumulative success rate was 76.04% according to the Misch classification and 56.34% according to the Albrektsson classification. The cumulative implant survival rate was 100%, although one implant was found to be affected by peri-implantitis at the second follow-up visit. Conclusions: The cumulative success rate of the implants dropped over time, corresponding to the progression of marginal bone resorption. The prevalence of peri-implantitis was very low, and the implant survival rate was not found to be related to the cumulative success rate.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.23 no.1
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• pp.34-40
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• 2014

There are several treatment options for rehabilitation of partial edentulism including the use of conventional or implant-retained fixed prostheses. However, such prosthetic options cannot always be possible because of compromised general and oral health (i.e. loss of supporting tissues, medical reasons, extensive surgical protocol and osseointegration failure of dental implant) as well as the affordability of patients. In some cases, removable partial denture provides easier access for oral hygiene procedures and the ability to correct discrepancies in dental arch relationships than implant fixed prosthesis. Recently, Implant Supported Removable Partial Denture (ISRPD) where to place dental implant in strategic position has been suggested to improve the limitation and shortcomings of conventional RPD. ISPRD can overcome mechanical limition of conventional RPD by placing implant in a favorable position and can be cost-effective, prosthetic solution for partially edentulous patients who are not immediate candidates for extensive, fixed implant supported restorations. Incorporation of dental implants to improve the RPD support and retention and to enhance patient acceptance should be considered when treatment planning for RPD. In this case, 59 years old male patient who received dental treatment of implant fixed prosthesis on both side of the upper jaw and implant overdenture on lower jaw showed implant abutment screw fracture on #15i and osseointegration failure on multiple number of implants. After removing failed implants, we planned ISRPD using #15i,24i,25i,26i and #23 natural tooth for RPD abutment. We fabricated #23 surveyed crown,#24i=25i=26i surveyed bridge and #15i gold coping for support,retention and stability for RPD. Periodic follow up check for 2years has been performed since the ISRPD delivery to the patient. No sign of screw loosening, fracture or bone resorption around abutment implants were detected.

• The Journal of Korean Academy of Prosthodontics
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• v.62 no.2
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• pp.131-139
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• 2024

In a edentulous patient, various methods can be employed for prosthetic treatment using implants, such as implant-supported fixed prostheses, overdentures, hybrid prostheses, and implant assisted removable partial denture. In this case, in a patient with moderate to severe chronic periodontitis requiring full arch extractions, implants were strategically placed using computer-guided surgery. In the maxilla, due to inadequate bone quality and quantity leading to insufficient initial stability, delayed loading was implemented, and interim prosthesis was used during the osseointegration period. In the mandible, stable initial stability was achieved, allowing for immediate loading to reduce patient discomfort. Primary stability is considered the most crucial factor for obtaining immediate loading, so a thorough clinical and radiological evaluation of the remaining alveolar bone quantity and quality must be conducted before surgery.

• Journal of Dental Rehabilitation and Applied Science
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• v.31 no.2
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• pp.126-133
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• 2015

Periodontal tissue destroyed by inflammation is difficult to achieve regeneration of the tissue and esthetic restorations only by surgical methods. In particular, improvement of esthetics is more difficult if the problem is related to the implant. A 23 year old woman suffered from unesthetic anterior implant prosthesis. According to her dental history, a repeated bone graft and soft tissue graft failed at a local dental clinic. It was needed to resolve the inflammation and to improve the esthetics. A free gingival graft and ridge augmentation accompanied by guided bone regeneration and a vascularized interpositional periosteal connective tissue graft was performed. Instead of implant prosthesis, a conventional fixed bridge was adopted for better esthetic result. The patient was satisfied with the esthetic conventional fixed prosthesis. This case report introduces esthetic rehabilitation of unesthetic implant prosthetics in the maxillary anterior dentition by a combination of surgical and prosthetic approaches.