• Journal of Periodontal and Implant Science
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• v.50 no.6
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• pp.406-417
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• 2020

Purpose: This study investigated whether the placement of ribose cross-linked collagen (RCLC) membranes without primary soft tissue closure predictably resulted in sufficient alveolar ridge preservation in contained and non-contained extraction sockets. Methods: Membranes were positioned across extraction sockets, undermining full-thickness flaps, and the gingival margins were fixed by double-interrupted sutures without crossed horizontal mattress sutures for 1 week. In non-contained sockets, a bone substitute was used to support the membrane within the bony envelope. Radiographs and clinical images obtained 4 months later were analyzed by ImageJ software using non-parametric tests. Results: In 18 patients, 20 extraction sockets healed uneventfully and all sites received standard-diameter implants (4.1, 4.8, or 5.0 mm) without additional bone augmentation. Soft tissues and the muco-gingival border were well maintained. A retrospective analysis of X-rays and clinical photographs showed non-significant shrinkage in the vertical and horizontal dimensions (P=0.575 and P=0.444, respectively). The new bone contained vital bone cells embedded in mineralized tissues. Conclusions: Within the limitations of this pilot study, open healing of RCLC membranes may result in sufficient bone volume for implant placement without additional bone augmentation in contained and non-contained extraction sockets.

• Development and Reproduction
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• v.2 no.1
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• pp.53-62
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• 1998

The lysosomal acid hydrolases including lysosomal acid phosphatase (LAP) are believed to play an important role in intracellular and extracellular degradation. LAP was reported to increase its activity in dedifferentiation stage during urodele limb regeneration. In the paresent study, LAP localization in the Mexican axolotl (Ambystoma mexicanum) limb regenerates was investigated by immunohistochemistry. LAP immunoreactivity with monoclonal antibody against Korean salamander (Hynobius leehii) LAP was observed mainly in the wound epidermis, blastema cells, muscle, and cartilage which were under dedifferentiation process in axolotl limb regenerates. Moreover, LAP immunoreactivity increased gradually during the early phase of lib regeneration and reached the peak level at dedifferentiation stage. However, as redifferentiation begans, LAP immunoreactivity decreased slowly to the basal level. Retinoic acid (RA) which is known to induce skeleton pattern duplication in regenerating urodele limb appears to enhance LAP immunoreactivity. In the RA-treate limg regenerates, LAP immunoreactivity was higher than in the normal regenerates. In addition, the LAP expression period was more extended in the RA treated regenerates than in the normal regenerates. These results suggest that RA is involved in the extension of dedifferentiation state in RA-treated limb regenerate.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.3
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• pp.229-236
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• 2009

Purpose: Some recent literatures report that it is possible to recover defected areas caused by enucleation of relatively large jaw cysts without using bone grafts. The aim was to find out whether spontaneous recovery of defected area with time occurred and what the contributing factors were. Materials and methods: In total, 194 patients were considered as patients. Out of these 194 patients, 74 patients who had no wound dehiscence and who were available for follow-up studies were selected. They were classified into two groups according to the size of radiolucent area in the preoperative panoramic radiographs: in one group, it was larger than $3{\times}4cm$, while in the other group, it was smaller than $3{\times}4cm$. Follow-up panoramic radiographs were taken immediately after the surgery, then after 3, 6, 9 and 12 months. On those radiographs, changes in size and density of the defected areas were observed using the Gray-level histogram of Adobe photoshop v7.0. Correlation between bone regeneration and factors such as the type and size of the cysts, age, sex, site of the cysts and systemic disease was evaluated using the General repeated measure and Mann-Whitney Test. Results: Analyses of panoramic radiographs showed that the recovery of radiopacity after 12 months was more than 97% on average in defected areas that were smaller than $3{\times}4cm$. in the defected areas that were larger than $3{\times}4cm$, considerable portion showed recovery of radiopacity. No statistically significant change was observed in bone density according to the type of cysts. Young patients under 20 years of age with highly active metabolism presented more significant bone regeneration than patients over 20 years of age. Bone regeneration was more hampered in patients who had medical disease, compared with patients who didn’t have any medical problem. No statistically significant change was seen in bone density according to sex. Changes in bone density according to the site of cysts such as maxilla, mandible, anterior or posterior region were not considered to be significant. Conclusion: Analyses of panoramic radiographs suggest that in approximately 12 months after the enucleation of cysts, clinically acceptable spontaneous bone regeneration can be observed even though normal bone graft procedures have not been applied.

• Journal of Periodontal and Implant Science
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• v.23 no.3
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• pp.359-373
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• 1993

The ultimate objective of periodontal therapy is not only stopping the progression of periodontal disease, but also promoting the regeneration of lost periodontal tissue. Guided Tissue Regeneration, which is based on the principle that the goal of periodontal regeneration can be achieved by preventing apical migration of gingival epithelium and blocking cells originating from connective tissue, has been developed and used as a clinical procedure, and although it has shown excellent results in connective tissue healing, there have not been many studies showing its effect on the regeneration of alveolar bone loss due to periodontal disease. The objectives of this study are to investigate the result of 12 months-long treatment following guided tissue regeneration using expanded polytetrafluoroehylene membrane, and to observe the presence of regenerated alveolar bone. Forty-one teeth from 28 patients with clinical diagnosis of periodontitis has been selected. In fifteen of those interproximal intrabony defects, only flap operation had been carried out, and designated as the control group. Twenty-six intrabony defects received e-PTFE membrane following flap operation, and designated as the experimental group. Eleven teeth whose membrane had been exposed were excluded from the experiment. Various measurements including probing depth, loss of attachment, probing bone level and gingival recession have been recorded at 6th month and 12th month, and the significance of the changes has been analyzed. The results are as follows: 1. Probing depth at 6th and 12th month has shown a significant decrease in both groups (p<0.01), but significantly higher decrease was found in the experimental group compared to the control at the month(p<0.05). 2. Loss of attachment at 6th and 12th month has shown a significant decrease in both groups, but significantly higher decrease was found in the experimental group compared to the control (p<0.05). 3. Probing bone level at 6th and 12th month has shown a insignificant decrease in the control group and significant decrease in the experimental group (p<0.01). Significantly higher decrease in probing bone level was found in the experimental group (p<0.05). 4. Gingival recession at 6th and 12th month has shown a statistically significant increase (p<0.05), and the control group showed higher increase compared to the experimental group although no statistical significance was found. As these results have shown, the use of e-PTFE membrane in intrabony pockets results in marked decrease in the loss of attachment and probing bone level. This seems to indicate that e-PTFE membrane may play a role in alveolar bone regeneration in intrabony defects.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.32 no.1
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• pp.16-22
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• 2023

Esthetic factors are very important in the success of maxillary anterior implant restoration. However, achieving esthetic results is difficult, especially in cases where periodontitis has resulted in severe alveolar bone loss. In the case of maxillary anterior teeth, the alveolar ridge resorption that begins immediately after tooth extraction interferes with the esthetic implant restoration. Therefore immediate implant placement can be performed to minimize the alveolar ridge resorption. However, in severe bone loss cases, immediate implant placement could result in esthetic failure, and this result might cause irreparable problems. We can also perform alveolar ridge preservation and then place implants later. On JCP published in 2019, there is the consensus of European academy of periodontology on the extraction socket management and the timing of implant placement. This consensus states that alveolar ridge preservation should be considered when there is severe labial bone loss in an esthetically important area such as maxillary anterior region. On performing the alveolar ridge preservation, we cannot obtain the primary wound closure, so secondary wound healing is induced with open membrane technique or soft tissue grafting should be performed for primary wound closure. However, the secondary wound healing can have a negative impact on bone regeneration, and soft tissue grafting such as FGG or CT graft can be burdensome for both patients and dentists. On the other hand, by using the granulation tissue in the extraction socket, primary closure can be achieved without soft tissue grafting. Also some studies have shown that granulation tissue in periodontal defects contains stem cells that may help in tissue regeneration. Based on this, implant restorations were performed on maxillary anterior teeth with severe alveolar bone loss by alveolar ridge preservation using granulation tissue. In spite of the severe bone defect of the extraction socket, relatively esthetic results could be obtained in implant restorations.

• The Journal of Korean Physical Therapy
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• v.9 no.1
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• pp.1-18
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• 1997

The purpose of this study is to investigate the effects of the low power Helium Neon-Infra Red(HeNe-IR) laser and the special electromagnetic therapeutic apparatus stimulation, which is usually designated as TDP by using the initial of Tending Diancibo Pu which is the Chinese inscribed with English, on wound healing in rat. The seventy-five Sprague-Dawley adult female and male rats were assigned to the experimental and control groups. Each rat was anesthetized with pentobarbital sodium, and three full-thickness incisions with 12mm length wert made on the back of the half cf the rats and three deep second degree burns were made on the back of the remainder of the rats. From 34 hours after being injured, the rats of the experimental laser group were irradiated with the 157mW electric power HeNe-IR laser for 2 minutes every day and the rats of the experimental TDP group were stimulated with TDP irradiation with the 4km spot distance for 20 minutes every day during the 17 days. The rats were sacrificed and the wound parts of its were incised on the first day, 4th day, 7th day, 10th day and 17th day respectively after the beginning of wound treatment with laser and TDP irradiation. The incised wound parts were processed appropriately for the light microscopic and electron microscopic examination. The length of incised wound was measured with microcaliper before the wound part was incised. There was a significant decrease in the length of the incised wound of the experimental laser and TDP group, compared with that of control group at 4th day, 7th day and 10th day(p<0.01) after surgery. Through the histological examination of the wound site, the more rapid epithelialization and collagen formation in experimental groups were showed, compared with control group. The histological results were analyzed and summarized as the follows; The epidermis begins to be regenerated and the granulation tissue begins to be changed to the mature pattern in the H-E stained incised skin of the laser and TDP treatment group on the 4th day. The epidermis shows the complete regeneration and the granulation tissue in the dermis in mostly to be matured in the laser and TDP treatment group on the 7th day, compared with control group. The chronic inflammatory cells are oberved and the necrosis of the collagen fibers are partially observed in control group on the 10th day. The dermis of the laser and TOP treatment group reveals relatively compactly arranged collgen bundles with the mature collagen fibers on the 10th day. The epidermis and dennis of the laser and TDP group are repaired normally and the hair follicles are well regenerated on the 17th day. The mild edema and the granulation tissue is observed in the dermis of the control groups and the delayed treatment process is observed on the 17th day. The Most of proliferated collagen fibrils are found to be compact and regular in electron micrograph of burn skin of the laser treatment group on the 10th day hut the interstitial eadema and some inflammatory cells are found in the control group. The above results suggest that through the visual and histological examination the epithelized epithelium and the proliferation of the collagen liters in the dermis occur very effectively with the low power laser treatment and the TDP treatment in the incised wound healing and the burn wound healing.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.29 no.4
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• pp.333-339
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• 2007

Adequate bone quantity is one of the important factor to obtain osseointegration after implantation. Guided bone regeneration (GBR) has widely used in implantation for reconstruction of bony defects. Since introducing this procedure, there are many studies about survival rate of implants, changing in surrounding bone volume after function. The purpose of this study was to evaluate the amount of resorption according to placement timing and survival rate after function. The subjects were patients who had been operated with GBR from Jun 2003 to Jun 2004 in Seoul National University Bundang Hospital. They were divided into simultaneous and delayed placement group. The follow up had been performed at the time of just after GBR, 1, 3, 6, 12, 24-month later and standard periapical radiographs were taken to estimate the bone level at the time. The total average of bone level change in radiographs was 1.94mm(${\pm}0.25$), and 1.92mm(${\pm}0.72$) in simultaneous installation, 2.03mm(${\pm}0.25$) in delayed installation. In this report, the survival rates were 92.2% in simulataneous group and 92.3% in delayed group. Insufficient primary stability, early contamination of wound, overloading, poor oral hygiene, and infection were thought to be associated factors in the failed cases.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.1
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• pp.27-35
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• 2006

Purpose: This study was performed to investigate the expression of the transforming growth factor (TGF)-1, in a rat calvarium defect model using particulate dentin and/or plaster of Paris, and correlate the bone regeneration process with the histologic events. Materials and Methods: Thirty-two Sprague-Dawley rats were divided into 4 groups of 8 animals each. A 1.0 cm-sized calvarial defects were made and the defect was filled with different graft materials as follows : Group A, the defects were filled with a mixture of particulate dentin and plaster of Paris with a 2:1 ratio; Group B, the defects were filled with plaster of Paris only; Group C, defects were filled with particulate dentin only; Group D, untreated control group. The animals were sacrificed by 1, 2, 4, 8 weeks after implantation. Excised wound tissues were processed for histology, immunohistochemistry and RT-PCR for the analysis of TGF-1 expression. Results: Gene expression of TGF-1 was detected for all experimental groups. The highest gene expression was observed in the specimen taken at the first week after implantation in Group A. According to the histologic and immunohistochemical studies, TGF-1 positive osteoblast-like cells were found in the early stage of healing after the implantation of particulate dentin and plaster of Paris. Conclusion: These findings suggest that TGF-1 may be related to new bone formation at the early healing process after the implantation of particulate dentin and plaster of Paris.

• Archives of Plastic Surgery
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• v.37 no.5
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• pp.600-606
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• 2010

Purpose: Although traditional and current treatment strategies may demonstrate success, persistence or recurrence of difficult-to-heal wounds remain significant problems. A novel product, Hyalomatrix$^{(R)}$ (Fidia Advanced Biopolymer, Abano Terme, Italy) is a bilayer of an benzyl esterified hyaluronan scaffold beneath a silicone membrane. The scaffold delivers hyaluronan to the wound, and the silicone membrane acts as a temporary epidermal barrier. We present the results obtained with Hyalomatrix$^{(R)}$ in the treatment of difficult-to-heal wounds. Methods: From November, 2008 to March, 2010, Hyalomatrix$^{(R)}$ has been used on total 10 patients with wounds that were expected difficult to heal with traditional and other current strategies. After average 37.4 days from development of wounds, Hyalomatrix$^{(R)}$ was applied after wound debridement. On the average, Hyalomatrix$^{(R)}$ application period was 17.6 days. After average 16.5 days from removal of Hyalomatrix$^{(R)}$, skin grafts was performed. Results: In all cases, regeneration of fibrous granulation tissues and edge re-epithelization were present after the application of the Hyalomatrix$^{(R)}$. And all of the previous inflammatory signs were reduced. After skin grafts, no adverse reactions were recorded in 9 cases. But in one case, postoperative wound infection occured due to a lack of efficient fibrous tissues. In this model, the Hyalomatrix$^{(R)}$ acts as a hyaluronan delivery system and a barrier from the external environments. In tissue repair processes, the hyaluronan performs to facilitate the entry of a large number of cells into the wounds, to orientate the deposition of extracellular matrix fibrous components and to change the microenvironment of difficult-to-heal wounds. Conclusion: Our study suggests that Hyalomatrix$^{(R)}$ could be a good and feasible approach for difficult-to-heal wounds. The Hyalomatrix$^{(R)}$ improves microenvironments of difficult-to-heal wounds, reduces infection rates and physical stimulus despite of aggravating factors.

• Journal of Periodontal and Implant Science
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• v.35 no.4
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• pp.1019-1037
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• 2005

The major goals of periodontal therapy are the functional regeneration of periodontal supporting structures already destructed by periodontal disease as well as the reduction of signs and symptoms of progressive periodontal disease. There have been many efforts to develop materials and therapeutic methods to promote periodontal wound healing. There have been increasing interest on the chitosan made by chtin. Chitosan is a derivative of chitin made by deacetylation of side chains. Chitosan has been widely studied as bone substitution and membrane material in periodontology. Many experiments using chitosan in various animal models have proven its beneficial effects. Tetracycline has been considered for use in the treatment of chronic periodontal disease and gingivitis. The aim of this study is to evlauate the osteogenesis of tetracycline blended chitosan membranes on the calvarial critical size defect in Sprague Dawley rats. An 8mm surgical defect was produced with a trephine bur in the area of the midsagittal suture. The rats were divided into five groups: Untreated control group versus four experimental group. Four types of membranes were made and comparative study was been done. Two types of non-woven membranes were made by immersing non-woven chitosan into either the tetracycline solution or chitosan-tetracycline solution. Other two types of sponge membranes were fabricated by immersing chitosan sponge into the tetracycline solution, and subsequent freeze-drying. The animals were sacrificed at 2 and 8 weeks after surgical procedure. The specimens were examined by histologic analyses. The results are as follows: 1. Clinically the use of tetracycline blended chitosan membrane showed great healing capacity. 2. The new bone formations of all the experimental group, non-woven and sponge type membranes were greater than those of control group. But, there was no significant difference between the experimental groups. 3. Resorption of chitosan membranes were not shown in any groups at 2 weeks and 8 weeks. These results suggest that the use of tetracycline blended chitosan membrane on the calvarial defects in rats has significant effect on the regeneration of bone tissue in itself. And it implicate that tetracycline blended chitosan membrane might be useful for guided tissue regeneration.