• 대한치과보철학회지
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• 제39권1호
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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.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제18권3호
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• pp.339-347
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• 1996

하악골 재건을 위한 여러 골이식 방법중 유리혈관화 견갑골은 다른 방법에 비해 여러 가지장점을 갖고 있다. 저자는 독일 Wuerzburg 대학에서 연수중 다수의 하악골 복합결손환자를혈관화 견갑골판을 이용 재건하여 우수한 결과를 얻는 것을 경험하였다. 견갑골 피판은 혈관분포를 보존하면서 여러 군데의 쐐기형 부분절골술에 의해 쉽게 하악골 외형에 따라 형성할 수 있었으며, 대부분의 증례에서 혈관경의 길이는 충분하였고, 수혜부의 조건에 따라 견갑골판 단독으로 또는 피부판을 포함하여 채취되었으며, 공여부의 유병율은 거의 없이 우수한 심미적 기능적 결과를 얻을 수 있었다. 결론적으로 이 유리골관은 다양한 피판의 유용성과 하악골의 3차원적인 재건 그리고 적은 유병율을 가지고 있어, 연조직을 포함한 하악골 복합결손부 재건에 매우 적합하리라 사료된다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권2호
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• pp.553-558
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• 2012

Purpose: This article reviews a few of the commonly used types of vascularized osseous free flaps in maxillofacial reconstruction, which still represents the gold standard of restoration. We also discuss the developing concepts in maxillofacial reconstruction. Recent findings: Most of the literature reconfirms the established patterns of reconstruction with the aid of vascularized osseous free flaps. This method of free-tissue transfer is also feasible in cases of osteoradionecrosis or bisphosphonate-related osteonecrosis of the jaw. These flaps are also suitable for prosthetic restoration using osseointegrated dental implants. Summary: Vascularized osseous free flaps still remain the standard of care. Improvements upon the free-tissue transfer method employing vascularized osseous free flaps, such as distraction osteogenesis, tissue engineering, and imaging techniques, currently require further development, but these technologies could lead to improved outcomes of maxillofacial reconstruction in the near future.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제37권
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• pp.8.1-8.6
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• 2015

Background: This study aimed to evaluate the clinical usefulness of autogenous fresh demineralized tooth (auto-FDT) graft prepared at the chairside for alveolar bone grafting during dental implant surgery. Methods: In total, 38 patients requiring both tooth extraction (for endodontic or periodontal reasons or third molar extraction) and alveolar bone regeneration for dental implant placement were included. Within 2 h after clean extraction, the teeth were prepared at the chairside to serve as bone graft material. In the same sitting, blocks or chips of this graft material were used to reconstruct defects at the osteotomy site simultaneously with or before implant placement. Twelve months after prosthesis fabrication and placement, the clinical findings and implant success rates were evaluated. Histological studies were randomly conducted for selected cases. Results: Clinical evaluation showed favorable wound healing with minimal complications and good bone support for the implants. No implant was lost after 12 months of function following prosthetic rehabilitation. Histological examination revealed new bone formation induced by the graft material. Conclusions: Chairside preparation of autogenous fresh demineralized teeth after extraction can be a useful alternative to the use of autogenous bone or other graft materials for the immediate reconstruction of alveolar bone defects to facilitate subsequent implant placement.

• Macromolecular Research
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• 제15권3호
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• pp.205-210
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• 2007

Collagen is the major structural protein of connective tissues. It can be used as a prosthetic biomaterial applicable to artificial skin, tendon, ligaments, and collagen implants. The objective of this study is to investigate the possibility of realizing wound dressing medical products by the synthesis of composite materials with collagen and a biodegradable polymer, PLLA, via a surface modification process. Type I collagen was obtained from pig skin by a separation process. The structural characteristics of the extracted collagen were confirmed by SDS-polyacrylamide (PAcr) gel electrophoresis (PAGE) and FTIR. Also, PLLA-g-PAcr was synthesized by the radical polymerization of acrylamide initiated by AIBN in the presence of PLLA. The surface of PLLA was modified by the presence of the acrylamide residues. The structural characteristics of the copolymer were analyzed by FTIR, $^1H-NMR$ and contact angle measurements. The water uptake and WVTR of the collagen/PLLA-g-PAcr composite tended to increase with increasing collagen concentration and with decreasing EDC concentration.

• 대한치과의사협회지
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• 제51권12호
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• pp.630-636
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• 2013

During the past decade, the use of osseointegrated implants as a foundation for prosthetic replacement of missing teeth has become highly predictable and successful. SPT(Supportive Periodontal Therapy) identified as regular visits to the therapist for periodontal control and maintenance in a well-organized scheme, the number of appointments per year following a pre-designed subject-tooth/implant-site risk assessment method. Peri-implant disease was a frequent finding in subjects having natural healthy dentition and in subjects without periodontitis. Supportive periodontal program were found to be strongly related to implant survival. This study demonstrates that regular maintenance reduces the risk for peri-implant inflammation significantly as compared with irregular maintenance. This underlines the value of the SPT in enhancing the long-term outcomes of implant therapy, particularly in subjects affected by periodontitis, in order to control reinfection and limit biological complications. It is highly recommended to maintain implant patients under a strict supportive periodontal treatment protocol that might contribute to implant survival, and regular maintenance reduces the risk for periimplant inflammation significantly as compared with irregular maintenance. Ideally, patients may be informed on the beneficial effect of a regular patient-related post-therapy care before implant insertion.

• 대한치과의사협회지
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• 제37권1호통권356호
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• pp.62-68
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• 1999

Patients who present with severe maxillary bone loss Secondary to trauma or resorption provide a unique diagnosis and difficulty in implant installation. To solve this problem, various bone grafting methods and graft materials can be used in these compromised cases. But for the patients required wide reconstruction, autogenous iliac bone has been used widely because of easy harvesting of much corticocancellous bone. Usually, implant installations are performed 6-12 months later after grafting. but this method necessary long treatment period and additional surgery. To avoid this disadvantages, bone grafting with immediate implant installations are frequently used. But special care is necessary to prevent postoperative complication in this method. We present three cases of veneer grafting with immediate implant installation. These patients had a knife-edge shaped alveolar bone due to labial alveolar bone loss. We reconstructed this alveolar bone with veneer grafting with iliac bone and performed immediate implant installation. There was no complications during healing periods in these three cases. Six months later, we found good survival of grafting bone and osseointegration of these implants, so we could perform prosthetic treatment successfully.

• 대한치과보철학회지
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• 제53권1호
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• pp.81-85
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• 2015

본 증례의 환자는 상악 전치부 보철물의 파절 및 기존에 사용하던 하악 의치의 불편감 때문에 임플란트를 이용한 고정성 보철을 원한다는 주소로 내원하였다. 상악동 거상술, 하악지 골이식과 함께 상악에 5개, 하악에 6개의 임플란트를 식립하였다. 전치부와 양쪽 구치부의 세 부분으로 나누어 임플란트 지지형 고정성 보철물을 장착하였다. 이상과 같은 과정을 통해 적절한 심미적, 기능적 결과를 얻었기에 이를 보고하고자 한다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제22권3호
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• pp.274-287
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• 2000

The use of dental implants has increased tremendously in recent years and is expected to increase even more in the future. The successful outcome of any implant procedure is surely dependent on interrelationship of the various components of an equation that includes biocompatibility of implant material, macroscopic and microscopic nature of the implant surface, the status of implant bed, surgical technique, undisturbed healing phase and subsequent prosthetic design and long-term loading phase. The purpose of this study was to clarify the effects of adrenalectomy on the osseointegration of pure titanium implants. Seventy rats, 11 weeks of age, were divided into two groups : an adrenalectomized group and a control group. Titanium screw implant(diameter, 2.0mm; length, 3.5mm) was placed into left tibia of 70 rats, 35 in control group and 35 in the experimental group. The rats were sacrificed at different time interval (1, 2, 3, 4, 6, 8, and 12 weeks after implantation) for histopathologic observation, histomorphometric analysis and immunohistochemistry with fibronectin and CD44 antibody. The results obtained from this study were as follows: 1. Histopathogically, findings, newly formed bone was seen at 3 weeks control group and became lamellar bone at 12 weeks. At 6 weeks, lipocytes were observed in bone marrow space. Thickness of regenerated trabecular bone increased till 6 weeks after then, that decreased gradually. 2. By histomorphometric analysis, marrow bone density and contact ratio of marrow bone to implant decreased significantly from 8 to 12 weeks in experimental group compared to control group and also total bone to implant contact ratio decreased significantly from 4 to 12 weeks in experimental group compared to control group. 3. Fibronectin immunoreactivity was very strong at 3 and 4 weeks control group. And after that reduced gradually. But it was continuously strong from 1 to 12 weeks experimental group. 4. CD44 immunoreactivity was very strong in the newly formed osteoblasts at 3 and 4 weeks control group. But it reacted minimally later. However, it reacted continuously strong from 3 to 12 weeks experimental group. From these results, bone to implant contact ratio decreased gradually from 4 weeks in adrenalectomized group compared to control group. CD44 and fibronectin immunoreactivities were strong at all times in adrenalectomized rats. Therefore, it could be stated that immature bone remained continuously for a long time and not readily proceeded into mature status.

• 대한치과의사협회지
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• 제56권5호
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• pp.263-276
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• 2018

Long-term survival and prognosis of narrow-diameter implants have been reported to be adequate to consider them a safe method for treating a deficient alveolar ridge. The objective of this study was to perform case report of narrow-diameter implants with a trapezoid-shape in anterior teeth alveolar bone. A 50-year-old male patient presented with discomfort due to mobility of all of the maxillary teeth and mandibular incisors. Due to destruction of alveolar bone, four anterior mandibular teeth were extracted. Soft tissue healing was allowed for approximately 3 months after the extraction, and a new design of implant placement was planned for the mandibular incisor area, followed by clinical and radiological evaluation. Implant placement was determined using an R2GATE surgical stent. The stability of the implants was assessed by ISQ measurements at the first and second implant surgery and after prosthetic placement. At 1 and 3 months and 1 year after implantation of the prosthesis, clinical and radiological examinations were performed. Another 50-year-old male patient presented with discomfort due to mobility of the mandibular central incisors. For the same reason as in the first patient, implant placement was carried out in the same way after extraction. ISQ measurements and clinical and radiological examinations were performed as in the previous case. In these two clinical cases, 12 months of follow-up revealed that the implant remained stable without inflammation or additional bone loss, and there was no discomfort to the patient. In conclusion, computer-guided implant surgery was used to place an implant in an optimal position considering the upper prosthesis. A new design of a narrow-diameter implant with a trapezoid-shape into anterior mandibular alveolar bone is a less invasive treatment method and is based on the contour of the deficient alveolar ridge. Through all of these procedures, we were able to reduce the number of traumas during surgery, reduce the operation time and total treatment period, and provide patients with more comfortable treatment.