• 대한치과보철학회지
• /
• 제29권2호
• /
• pp.267-284
• /
• 1991

Since the concept of a direct contact between bone and implants, without interposed soft- tissue layers, was reported by Dr. $Br{\aa}nemark$, there has been increasing necessity for correct under-standing of bone-implant interface and surrounding tissue response. Beside quality of bone, surgical technique, load applied to implants, one must consider implant materials, design and surface characteristics to obtain osseointegration. In this study HA plasma-sprayed implants, TPS implants and $Al_2O_3$ implants were inserted into the alveolar bone of dog and tissue response was observed with radiograph, stereoscope, light microscope, and scanning electron microscope. Results were as follows : 1. There was rapid and active bone formation in the region adjacent to HA plasma-sprayed implants but in the deep supporting bone only slight bone formation was seen. 2. There was considerable lamella bone formation in the region adjacent to TPS implants and the deep supporting bone became more compact. 3. There was some gap and sclerosing bone formation in the adjacent region of $Al_2O_3$ implants, but there was irregular new bone formation in the deep supporting bone. Therefore, it seems that $Al_2O_3$ is not adequate for osseointegrated implants.

• Journal of Periodontal and Implant Science
• /
• 제42권1호
• /
• pp.20-24
• /
• 2012

Purpose: The purpose of this study was to evaluate the soft tissue and bone change around two adjacent implants in onestage implant surgery. Methods: Eleven subjects (7 males, 4 females) who were needed placement of 2 adjacent implants in the molar area were included. The two implants were placed with the platform at the level of the alveolar crest. The interproximal bone between the 2 implants was not covered with gingiva. After surgery, an alginate impression was taken to record the gingival shape and radiographs were taken to evaluate implant placement. Using a master cast, the gingival height was measured at baseline, 4 weeks, and 12 weeks. In the radiograph, the alveolar bone level was measured at the mesial and distal side of both implants at baseline and 12 weeks. Results: The exposed bone was covered with gingiva at both 4 and 12 weeks. Loss of alveolar bone around implants was found in all areas. The alveolar bone level in the exposed bone area did not differ from that in the non-exposed area. Conclusions: This study showed that the alveolar bone level and gingival height around 2 adjacent implants in the exposed bone area did not differ from that in unexposed bone area.

• Journal of Periodontal and Implant Science
• /
• 제34권3호
• /
• pp.535-541
• /
• 2004

The aims of the present study are firstly to investigate the amount of bone loss around non-submerged implants placed in the posterior region and secondly to investigate the relationship between inter-implant and implant-tooth distance and peri-implant bone loss. Thirty-one subjects with 60 implants were selected consecutively from the implant patient pool at the department of Chonbuk National University Hospital. To be included in the study subject, the implant should have been functioned more than 6 months after loading. Inter-implant and implant-tooth distance, distance between implant shoulder and the first bone contact with the implant(DIB) were measured from the scanning image of the radiograph of each implant. The result showed that; 1. inter-implant distance has a statistically significant relationship with DIB in Pearson correlation analysis. 2. the DIB at the implant facing surface of the implant was greater than that of tooth facing surface of the implant. Within limitation of this study, it is suggested to place an implant not too closely to adjacent implants, and the presence of a tooth adjacent to an implant may keep the level of tooth-facing surface of the implant. Further studies with a prospective design are needed to elucidate the relationship between bone changes and various dimensions around implants.

• 대한심미치과학회지
• /
• 제25권1호
• /
• pp.15-24
• /
• 2016

전치부에서는 비록 임플란트가 기능적으로 문제가 없다고 하더라도 심미적인 문제가 있다면 실패로 간주한다. 2003년 Kan은 임플란트의 골 레벨은 인접치아의 골 레벨에 의해 결정된다고 보고하였다. 그 후로 많은 학자들이 인접치아의 골 소실이 있는 증례에서 어떻게 심미적 결과를 얻을 수 있는지에 대하여 연구해왔다. 2012년 Takino가 지금까지 여러 저널을 정리 및 분류하여 Class 1부터 4로 발표하였다. Class 1과 2는 인접치의 골소실이 없는 경우, Class 3,4는 인접치의 골소실이 있는 경우로 나누어서 각 분류마다 최적의 심미를 얻을 수 있는 방법에 대하여 설명하였다. 인접치의 골소실이 없는 경우에는 쉽게 심미적 결과를 얻을 수 있으나 인접치까지 골소실이 있는 경우는 수술이 복잡해지고 심미적 결과를 장담하기 힘들다. 따라서 장기적인 안정적 결과를 유지하기 위해서는 인접치에 대한 골재생술이 필요하다. 하지만 그 과정이나 치료법이 너무 복잡하여 이 저널에서는 기존의 수술법을 단순화하여 쉽게 비슷한 결과를 얻을 수 방법을 보고하고자 한다.

• Asian Spine Journal
• /
• 제12권6호
• /
• pp.1092-1099
• /
• 2018

Study Design: In-vitro biomechanical investigation. Purpose: To evaluate the biomechanical effects of the degeneration of the biodegradable cervical plates developed for anterior cervical discectomy and fusion (ACDF) on fusion and adjacent levels. Overview of Literature: Biodegradable implants have been recently introduced for cervical spine surgery. However, their effectiveness and safety remains unclear. Methods: A linear three-dimensional finite element (FE) model of the lower cervical spine, comprising the C4-C6 vertebrae was developed using computed tomography images of a 46-year-old woman. The model was validated by comparison with previous reports. Four models of ACDF were analyzed and compared: (1) a titanium plate and bone block (Tita), (2) strong biodegradable plate and bone block (PLA-4G) that represents the early state of the biodegradable plate with full strength, (3) weak biodegradable plate and bone block (PLA-1G) that represents the late state of the biodegradable plate with decreased strength, and (4) stand-alone bone block (Bloc). FE analysis was performed to investigate the relative motion and intervertebral disc stress at the surgical (C5-C6 segment) and adjacent (C4-C5 segment) levels. Results: The Tita and PLA-4G models were superior to the other models in terms of higher segment stiffness, smaller relative motion, and lower bone stress at the surgical level. However, the maximal von Mises stress at the intervertebral disc at the adjacent level was significantly higher in the Tita and PLA-4G models than in the other models. The relative motion at the adjacent level was significantly lower in the PLA-1G and Bloc models than in the other models. Conclusions: The use of biodegradable plates will enhance spinal fusion in the initial stronger period and prevent adjacent segment degeneration in the later, weaker period.

• 대한치과교정학회지
• /
• 제48권5호
• /
• pp.283-291
• /
• 2018

Objective: This study was conducted to perform histomorphometric evaluations of the bone surrounding orthodontic miniscrews according to their proximity to the adjacent tooth roots in the posterior mandible of beagle dogs. Methods: Four male beagle dogs were used for this study. Six orthodontic miniscrews were placed in the interradicular spaces in the posterior mandible of each dog (n = 24). The implanted miniscrews were classified into no loading, immediate loading, and delayed loading groups according to the loading time. At 6 weeks after screw placement, the animals were sacrificed, and tissue blocks including the miniscrews were harvested for histological examinations. After analysis of the histological sections, the miniscrews were categorized into three additional groups according to the root proximity: high root proximity, low root proximity, and safe distance groups. Differences in the bone-implant contact (BIC, %) among the root proximity groups and loading time groups were determined using statistical analyses. Results: No BIC was observed within the bundle bone invaded by the miniscrew threads. Narrowing of the periodontal ligament space was observed in cases where the miniscrew threads touched the bundle bone. BIC (%) was significantly lower in the high root proximity group than in the low root proximity and safe distance groups. However, BIC (%) showed no significant differences among the loading time groups. Conclusions: Regardless of the loading time, the stability of an orthodontic miniscrew is decreased if it is in contact with the bundle bone as well as the adjacent tooth root.

• Journal of Periodontal and Implant Science
• /
• 제33권4호
• /
• pp.563-571
• /
• 2003

One of the central components of periodontal therapy is the improvement of esthetics. The presence and appearance of interdental papillae plays an important role of periodontal esthetics. The aim of the present study was to investigate how immediate provisional restoration preserve the shape of interdental papilla around the extraction socket and the width of bucco-lingual of gingiva. Another aim was to investigate the change in the interdental papilla and the amount of vertical bone fill of a extraction socket in relation to the interdental alveolar bone levels adjacent the alveolar socket. A total of 19 patients (11 male, 8 female, mean age of 50.57${\pm}$8.16), who visited the Department of Periodontology, Pusan National University and had more than one anterior tooth scheduled to be extracted due to an advanced periodontal disease were included in the present study. After initial periodontal therapy, the extracted teeth were reshaped of the root and placed into the socket followed by splinting with adjacent teeth with self-curing resin. The width of hucco-lingual of gingiva and interdental papilla height were measured at baseline, 1, 3, 6, 9 and 12 month and the periapical radiographic examination were taken at baseline, 6 and 12month following the extraction. The amount of vertical bone fill in the extraction socket were calculated. At 12 months following the extraction, the changes in mesial and distal interdental papilla and the width of bucco-lingual showed -1.06${\pm}$0.48mm, -0.844${\pm}$0.50mm, -1.50${\pm}$0.96m, relatively. The positional change in the interproximal papillae was significantly associated with the interdental bone level adjacent to the extraction socket(p=0.028). The higher the interproximal bone level adjacent the extraction socket, the greater the amount of bone fill in the extraction socket(p<0.001). In conclusion, it was thought that immediate provisional restoration could minimize the loss of the width of bucco-lingual and interproximal papillae around the extraction socket. In addition, the higher the interproximal bone level adjacent the extraction socket, the greater the amount of bone fill and the smaller the reduction of papillary height around the extraction socket.

• 대한골관절종양학회지
• /
• 제13권2호
• /
• pp.201-206
• /
• 2007

연부조직 육종의 치료에서 광범위 절제술은 필수적이며, 국소 재발율은 수술시 절제연과 매우 밀접한 관계를 가지는 것으로 알려져 있다. 연부조직 육종이 뼈와 바로 접하여 있는 경우 치료의 방향을 정하는데 어려움이 있다. 인접 골을 같이 절제하지 않으면 충분한 절제연을 얻을 수가 없고, 뼈를 같이 절제하면 수술이 어려워지면서 많은 합병증을 가져 올 수 있는 재건술이 필요해진다. 저자들은 슬와부 신경 및 혈관 과 근위 경골 사이에 발생하여 경골을 침투한 활막육종을 치료한 경험을 증례 보고한다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제26권1호
• /
• pp.24-39
• /
• 2000

Various methods and graft materials have been used to fill in the defect adjacent to the implants and considered as clinically acceptable. But it is not clear whether the regenerated bone increases the implant-bone contact and supports the implant. The purpose of this study is to evaluate regenerated bone surrounding implants using bone morphogenetic protein(BMP) and demineralized freeze-dried bone(DFDB), and the interfaces between implants and regenerated bone. bBMP was extracted and partially purified from the bovine bone matrix using heparine chromatography. Demineralized freeze-dried bone was made from the dog. Inactive insoluble collagenous bone matrix(IBM) of dog was used as carrier of bBMP. Interfaces of titanium coated epoxy resin implants were processed for demineralized section for transmission electron microscopy(TEM) and those of screw type implants were for nondemineralized section for light and fluoromicroscopic examination. Implants were inserted in the inferior border of mandible of adult dogs and artificial bony defects($3{\times}3{\times}4mm$) were made at the mesial and distal side of implants. Defects were filled with BMP(BMP group) and DFDB(DFDB group). For the fluoromicroscopic examination, the fluorescent dyes(oxytetracycline, calcein green, alizarin red) were injected 2, 4, 6, 8, 12 weeks after implantation. The experimental animals were sacrificed at the 6th and the 12th week and their mandible were extirpated and processed for examination with light microscopy, fluoromicroscopy and TEM. The obtained results were as follows : 1. By the light microscopic findings, the defects were filled with woven bone at the 6th week and compact bone at the 12th week, and the osseointegrations were seen in both groups. There was no histological difference between them. 2. On the basis of the histomorphometric analysis, BMP group(6th week: 40.25%, 12th week: 56.04%) had higher bony contact ratio than DFDB group(38.37%, 42.63%). There was significant difference between two groups at the 12th week(p<0.05). 3. The amount of bone formation in BMP group was more prominent than in DFDB group. Significant difference was noted among two groups at the 6th and the 8th week(p<0.05). 4. By the transmission electron microscopic findings, $0.4-2{\mu}m$ soft tissue layer was found in adjacent to the interfaces and over the collagen fibrils of bone at the 6th week. However, about 100nm amorphous layer was noted at the interface or collagen fibrils directly extended to the titanium surface at the 12th week. There was no significant difference between two groups. 5. These results suggest that BMP and DFDB can be used as good graft materials in the regeneration of bone adjacent to implant, and BMP is more valuable as a bone inducer than DFDB.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제20권3호
• /
• pp.237-240
• /
• 1998

Aneurysmal bone cyst is a benign lesion of bone consisting of a septated, cystic cavity filled with non-endothelium-lined, blood-filled spaces. As it grows, expanding and destroying the affected part of the bone by direct compression, the lesion characteristically produces a prominent bulging of the affected bone, which eventually erodes the overlying cortex. Patients rarely complain of pain unless the cyst affects adjacent nerves or its expasion is great enough to impinge on the surrounding joints and soft tissue. Teeth adjacent to the cyst may be displaced, but usually remain vital. Development of the lesion in the craniofacial region is rare, and the mandible is more often affected than the maxilla. Complete surgical excision is used to treat aneurysmal bone cyst, with either curettage or composite resection. This is a case report of 49 years old female with aneurysmal bone cyst treated with surgical excision & DFDB graft.