• Journal of Periodontal and Implant Science
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• v.47 no.4
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• pp.251-262
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• 2017

Purpose: The purpose of this study was to investigate the effects of implant tilting and the loading direction on the displacement and micromotion (relative displacement between the implant and bone) of immediately loaded implants by in vitro experiments and finite element analysis (FEA). Methods: Six artificial bone blocks were prepared. Six screw-type implants with a length of 10 mm and diameter of 4.3 mm were placed, with 3 positioned axially and 3 tilted. The tilted implants were $30^{\circ}$ distally inclined to the axial implants. Vertical and mesiodistal oblique ($45^{\circ}$ angle) loads of 200 N were applied to the top of the abutment, and the abutment displacement was recorded. Nonlinear finite element models simulating the in vitro experiment were constructed, and the abutment displacement and micromotion were calculated. The data on the abutment displacement from in vitro experiments and FEA were compared, and the validity of the finite element model was evaluated. Results: The abutment displacement was greater under oblique loading than under axial loading and greater for the tilted implants than for the axial implants. The in vitro and FEA results showed satisfactory consistency. The maximum micromotion was 2.8- to 4.1-fold higher under oblique loading than under vertical loading. The maximum micromotion values in the axial and tilted implants were very close under vertical loading. However, in the tilted implant model, the maximum micromotion was 38.7% less than in the axial implant model under oblique loading. The relationship between abutment displacement and micromotion varied according to the loading direction (vertical or oblique) as well as the implant insertion angle (axial or tilted). Conclusions: Tilted implants may have a lower maximum extent of micromotion than axial implants under mesiodistal oblique loading. The maximum micromotion values were strongly influenced by the loading direction. The maximum micromotion values did not reflect the abutment displacement values.

• 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.

• The Journal of Korean Academy of Prosthodontics
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• v.55 no.2
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• pp.218-224
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• 2017

The implant-supported fixed dental prosthesis in irradiated maxilla needs meticulous treatment planning due to low bone healing capacity. All-on-4 concept implantation can reduce the number of implants to be placed avoiding bone grafting procedure. Conventionally, prefabricated angled abutments for tilted implants have been used. However, in this case, it was replaced with computer-aided design and computer-aided manufacturing (CAD/CAM) abutment. This case report described all-on-4 concept implantation and fabrication of CAD/CAM zirconia fixed dental prostheses using CAD/CAM titanium abutments.

• Journal of Korean Dental Science
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• v.13 no.2
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• pp.73-80
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• 2020

Purpose: The purpose of this case study series was to introduce successful implant cases that used the palatal bone in patients with severe maxillary alveolar bone atrophy or defects. Case Presentation: In this case series study, a total of four patients underwent implant placement in the palatal bone of the maxilla. A total of 6 implants were installed using the palatine bone. The patients' ages ranged from 40 to 73 years with an average age of 63.5 years. The patients had maxillary sinus-related diseases, such as maxillary sinusitis, oroantral fistula, and dentigerous cysts, prior to implantation. To achieve initial stability, the implants were placed on the palatal side, and buccally tilted. The average postoperative recovery period was 8 months. No postoperative complications occurred in any of the cases, and the approach was used without reported issues. Conclusion: Implant treatment by securing the initial fixation in the palatal bone is a good alternative when an implant must be installed in a patient who requires extensive and invasive bone graft.

• The Journal of Korean Academy of Prosthodontics
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• v.56 no.1
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• pp.88-94
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• 2018

Recently, digital implant systems are expanding its influence in dental area. Due to technical improvement, they jumped over their limits nowadays. We can use these newest systems to treat edentulous patient, from implant surgery to fabrication of prosthesis. In this case, The patient was a fifty years old female. She had a full edentulous ridge on mandible and wanted to reconstruct occlusion with using implants. We planned to use digital implant system with "all-on-4" concept on mandible and produced surgical guide for flapless implant surgery. After the surgery, we tried to fabricate full arch prosthesis just using a digital devices and confirmed satisfying result.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.49 no.5
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• pp.278-286
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• 2023

Objectives: This review assessed the performance of implant-supported fixed hybrid prostheses in 21 patients who received a total of 137 implants between 2003 and 2010. The implants were evaluated for marginal bone resorption, complications, success rate, and survival rate based on their vertical angularity, type of bone graft, and measured implant stability. Materials and Methods: One-way ANOVA and chi-square tests were used to analyze the relationships among long-term evaluation factors and these variables. The mean initial bone resorption in the implant group with a vertical angle of more than 20° was 0.33 mm and mean final bone resorption was 0.76 mm. In contrast, the mean initial bone resorption in the implant group with a vertical angle of less than 10° was 1.19 mm and mean final bone resorption was 2.17 mm. Results: The results showed that mean bone resorption decreased with an increase in the vertical placement angle of the implants used in fixed hybrid prostheses, as well as in the group without additional bone grafts and those with high implant stability. The success rate of implants placed after bone grafting was found to be higher than those placed simultaneously. Conclusion: These results suggest that implant-supported fixed hybrid prostheses may be an effective treatment option for edentulous patients, and intentionally placing implants with high angularity may improve outcomes.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.39
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• pp.33.1-33.10
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• 2017

Dental implants are a common treatment for the loss of teeth. This paper summarizes current knowledge on implant surfaces, immediate loading versus conventional loading, short implants, sinus lifting, and custom implants using three-dimensional printing. Most of the implant surface modifications showed good osseointegration results. Regarding biomolecular coatings, which have been recently developed and studied, good results were observed in animal experiments. Immediate loading had similar clinical outcomes compared to conventional loading and can be used as a successful treatment because it has the advantage of reducing treatment times and providing early function and aesthetics. Short implants showed similar clinical outcomes compared to standard implants. A variety of sinus augmentation techniques, grafting materials, and alternative techniques, such as tilted implants, zygomatic implants, and short implants, can be used. With the development of new technologies in three-dimension and computer-aided design/computer-aided manufacturing (CAD/CAM) customized implants can be used as an alternative to conventional implant designs. However, there are limitations due to the lack of long-term studies or clinical studies. A long-term clinical trial and a more predictive study are needed.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.1
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• pp.70-81
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• 2009

Statement of problem: The position and length of cantilever influence on the stress distribution of implants, superstructure and bone. In edentulous mandible, implant-supported cantilever prostheses that based 4 or 6 implants between mental foramens has been attempted. Excessive bite force loaded at cantilever prosthesis causes bone resorption and breakage of superstructure prosthesis around posterior implants. To complement the cantilever length of conventional prosthesis, In 1992, (McCartney) introduced "cantilever-rest-implant" and Malo reported "All-on-Four" in 2003. Purpose: Analyze and compare the stress distribution of conventional cantilever prostheses with rest implant and All-on-$Four^{TM}$ implant prostheses. Material and method: The external loads(300 N vertically, 75 N horizontally) are applied to first molar area. The stress value, stress distribution and aspect of stress dispersion are analyzed by three-dimensional finite element analysis program, ANSYS ver. 10.0. Results: 1. The rest implant and "All-on-Four" implant system are superior to conventional cantilever prostheses to reduce stress on the bone and the superstructure around implants. 2. The rest implant was of the greatest advantage to stress distribution on bone, implant and superstructure. 3. With same number of implants, distally tilted implants are preferred to conventional cantilever prostheses for reducing the length of cantilever.

• Journal of Dental Rehabilitation and Applied Science
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• v.35 no.1
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• pp.37-45
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• 2019

In the case of edentulous patients, the total amount of occlusal force is dispersed by the keratinized gingiva during mastication, in result, causing lower masticatory and chewing efficiency. In particular, the mandibular area has more side effects such as pain than the maxilla has. It gets worse when the patient has more absorption of alveolar bone, but the implant treatment is often interrupted due to the existence of the inferior alveolar nerve. In this case, a patient treated with the all-on-4 method by placing the implant in the anterior part of mandible and with the conventional complete denture for the maxilla has maintained without complications and was satisfied with the restoration both functionally and esthetically.

• Journal of Periodontal and Implant Science
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• v.38 no.2
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• pp.215-224
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• 2008

Purpose: These case reports show the orthodontic treatment of lower anterior incisors with gingival recession. Materials and Methods: Three cases were treated by an orthodontist and a periodontist. Each case had lingually tilted lower anterior incisors, anterior crossbite and skeletal Cl III pattern. Results: A variety of etiological factors were thought to cause gingival recession: aging, oral hygiene, tooth malpositioning, occlusal trauma. Conclusion: Due to the interaction among many possible contributing factors, it is difficult to predict whether further gingival recession may occur at a given site. The position and the movement of the lower anterior incisors with gingival recession are important factors in diagnosis and orthodontic treatment planning.