• Maxillofacial Plastic and Reconstructive Surgery
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• v.42
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• pp.13.1-13.6
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• 2020

Background: The aim of this study was to evaluate the factors that may affect implant fixture fractures. Methods: Patients who experienced implant fixture removal at Seoul National University Bundang Hospital from 2007 to 2015 due to implant fixture fracture were included. Implant/crown ratio, time of implant fracture, clinical symptoms before implant fracture, treatment of fractured implants, and the success and survival rate of the replaced implants were evaluated retrospectively. Results: Thirteen implants were fractured in 12 patients. Patient mean age at the time of fracture was 59.3 years. Of the 13 implants, 7 implants were placed at our hospital, and 6 were placed at a local clinic. The mean crown/implant ratio was 0.83:1. The clinical symptoms before fracture were screw loosening in five implants, marginal bone loss in five implants, and the presence of peri-implant diseases in five implants. All the fractured implants were removed, and 12 out of the 13 sites were re-implanted. Parafunctions were observed in two patients: one with bruxism and one with attrition due to a strong chewing habit. Conclusions: Several clinical symptoms before the fracture of an implant can predict implant fixture failure. Therefore, if these clinical symptoms are observed, appropriate treatments can be taken before more serious complications result.

• The Journal of Korean Academy of Prosthodontics
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• v.39 no.1
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• pp.25-36
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• 2001

Among the numerous factors contributing to implant failure, the most common are infection, failure of proper healing and overload. These factors may occur combined. Implant fractures are one of the complications resulting from overload. Implant fracture is not a common feature, but once it occurs it causes very unpleasant circumstances for the patient as well as for the practitioner. Only few studies have been reported regarding this subject. Thus, little is known about its solutions. It is important that analyzing reasons for implant fracture and finding appropriate solutions. Factors leading to implant fracture are design, material defects, nonpassive fit of prosthetic framework and biomechanical overload. Previous studies have reported that implant fractures ares associated with marginal bone loss and occur mostly in the posterior regions and that most patients showing parafunctional habits also have implant fracture. Abutment and gold screw loosening or fracture were also observed in some of the cases previous to implant fracture. Similar observations were seen in our hospital as well. The following cases will present implant fracture cases which have been successfully treated regarding function and biomechanics. This was achieved by means of using increased number of futures, increasing fixture diameter and establishing proper occlusion.

• Journal of Korean Dental Science
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• v.6 no.1
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• pp.4-12
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• 2013

Purpose: This study sought to verify the usefulness of mini-implant and surgical steel wire in the treatment of mandibular fracture through the objective identifi cation of the change of bone structure and bone density before and after reduction by evaluating radiological change through fractal analysis when mandibular fracture is treated using mini-implant and surgical wire. Materials and Methods: This study looked at 45 patients (males: 38, female: 7) diagnosed with mandibular fracture in the oral and maxillofacial surgery division of Chung-Ang University Dental Hospital and who received open reduction and intra-osseous fi xation. Result: The average fracture dimension values were higher for the group of the patients who had mini-implants and surgical wire treatment. Conclusion: Based on the results of the study on the usefulness of the reduction technique using mini-implant and surgical steel wire in the treatment of mandibular fracture through the fractal analysis method, the reduction technique using mini-implant and surgical steel wire is regarded as an effective method of minimizing the gap between mandibular fracture fragments.

• The Journal of Advanced Prosthodontics
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• v.10 no.2
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• pp.155-162
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• 2018

PURPOSE. The aim of this study was to compare the fracture of implant component behavior of external and internal type of implants to suggest directions for successful implant treatment. MATERIALS AND METHODS. Data were collected from the clinical records of all patients who received WARANTEC implants at Seoul National University Dental Hospital from February 2002 to January 2014 for 12 years. Total number of implants was 1,289 and an average of 3.2 implants was installed per patient. Information about abutment connection type, implant locations, platform sizes was collected with presence of implant component fractures and their managements. SPSS statistics software (version 24.0, IBM) was used for the statistical analysis. RESULTS. Overall fracture was significantly more frequent in internal type. The most frequently fractured component was abutment in internal type implants, and screw fracture occurred most frequently in external type. Analyzing by fractured components, screw fracture was the most frequent in the maxillary anterior region and the most abutment fracture occurred in the maxillary posterior region and screw fractures occurred more frequently in NP (narrow platform) and abutment fractures occurred more frequently in RP (regular platform). CONCLUSION. In external type, screw fracture occurred most frequently, especially in the maxillary anterior region, and in internal type, abutment fracture occurred frequently in the posterior region. placement of an external type implant rather than an internal type is recommended for the posterior region where abutment fractures frequently occur.

• The Journal of the Korean dental association
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• v.53 no.5
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• pp.360-367
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• 2015

Purpose : The purpose of this study was to evaluate the effect of amount of cantilever in intra-crown according to implant fixture position on mechanical strength of internal conical joint type implant. Materials and Methods : Internal conical joint type implant fixture, abutment screw, abutment was connected and gold alloy prostheses were fabricated and cemented on abutment. For fatigue fracture test, the specimens were loaded to the 350 N, 2,000,000 cycle on 3, 4, 5, and 6 mm off-center of gold alloy prostheses. The fracture pattern of implant component was observed. Results : No fatigue fracture found on 3 and 4 mm group. But initial crack pattern found on 3 specimens of 4 mm group. Fatigue fracture found on all specimens of 5 mm group. But complete fracture was not observed. One specimen of 6 mm group fracture completely. Implant fixture fracture wax not observed. Conclusion : The mechanical failure of implant prostheses increased with the loading area farther from center of implant fixture. To reduce mechanical problem of internal joint type implant, surgical and prosthetic consideration is needed.

• Journal of Dental Rehabilitation and Applied Science
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• v.36 no.2
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• pp.138-144
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• 2020

Implant fracture is rare, but one of the most serious problem in implantation. Treatment of implant fracture can be different according to the extent of the fracture and on the state of the surrounding prosthetic restoration. Maintaining or submerging implant after treatment of peri-implantitis can be useful options for cases of tear-like fracture on the coronal area of an implant.

• The Journal of the Korean dental association
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• v.58 no.9
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• pp.583-589
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• 2020

If the implant is planted in the wrong position or direction, it is disadvantageous for stress distribution, and it is easy to cause complications such as screw loosening, abutment fracture, and implant fracture. If the position or orientation of the implant is not good, efforts should be made to minimize the problem through proper implant prosthetic treatment. In this article, the prosthetic method for facilitating future maintenance in cases with poor implant placement or orientation will be presented.

• Archives of Craniofacial Surgery
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• v.18 no.2
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• pp.137-140
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• 2017

Alloplastic materials used for orbital fracture reconstruction can induce complications, such as infection, migration, extrusion, intraorbital hemorrhage, and residual diplopia. Silicone is one of the alloplastic materials that has been widely used for decades. The author reports a rare case of spontaneous extrusion of a silicone implant that was used for orbital fracture reconstruction 30 years earlier. A 50-year-old man was admitted to the emergency room for an exposed substance in the lower eyelid area of the left eye, which began as a palpable hard nodule a week earlier. The exposed material was considered to be implant used for previous surgery. Under general anesthesia, the implant and parts of the fibrous capsule tissue were removed. Several factors hinder the diagnosis of implant extrusions that occur a long period after the surgery. So, surgeons must be aware that complications with implants can still arise several decades following orbital fracture reconstruction, even without specific causes.

• The Journal of the Korean dental association
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• v.53 no.5
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• pp.307-317
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• 2015

Although the long-term success of osseointegrated endosseous implants for the support of fixed dental prostheses has been reported, the increasingly widespread use of implant-supported prostheses has led to problems associated with their structural integrity. The most common biomechanical complications observed in dental implant treatment are fracture and screw loosening. The nature of loosening or fracture of dental implant components is complex, since it involves fatigue, fitness, and varied chewing patterns and loads. To assess the service life of the components of the prosthetic system, a knowledge of the loads transmitted through the system is necessary. Design of the final restoration and occlusion in relation to the geometry of a prosthetic restoration has a great influence on the mechanical loading of the implant. It is proposed that control of force in oral cavity may play a larger role in failures than previously believed. Based on theoretic consideration and clinical experiences with dental implant, this article gives simple guidelines for controlling these loads.

• The Journal of Advanced Prosthodontics
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• v.8 no.5
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• pp.388-395
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• 2016

PURPOSE. The purpose of this study was to evaluate the resistance to deformation under static overloading by measuring yield and fracture strength, and to analyze the failure characteristics of implant assemblies made of different titanium grades and connections. MATERIALS AND METHODS. Six groups of implant assemblies were fabricated according to ISO 14801 (n=10). These consisted of the combinations of 3 platform connections (external, internal, and morse tapered) and 2 materials (titanium grade 2 and titanium grade 4). Yield strength and fracture strength were evaluated with a computer-controlled Universal Testing Machine, and failed implant assemblies were classified and analyzed by optical microscopy. The data were analyzed using the One-way analysis of variance (ANOVA) and Student's t-test with the level of significance at P=.05. RESULTS. The group $IT4_S$ had the significantly highest values and group IT2 the lowest, for both yield strength and fracture strength. Groups $IT4_N$ and ET4 had similar yield and fracture strengths despite having different connection designs. Group MT2 and group IT2 had significant differences in yield and fracture strength although they were made by the same material as titanium grade 2. The implant system of the similar fixture-abutment interfaces and the same materials showed the similar characteristics of deformation. CONCLUSION. A longer internal connection and titanium grade 4 of the implant system is advantageous for static overloading condition. However, it is not only the connection design that affects the stability. The strength of the titanium grade as material is also important since it affects the implant stability. When using the implant system made of titanium grade 2, a larger diameter fixture should be selected in order to provide enough strength to withstand overloading.