• Journal of Periodontal and Implant Science
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• v.42 no.5
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• pp.158-165
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• 2012

Purpose: Recent interest has focused on intentional replantation to restore an original tooth. Some studies have shown successful results with intentional replantation for periodontally involved teeth. For long-term success of replantation, a healthy periodontal status of the recipient site is required so that delayed replantation is more suitable for periodontally involved teeth. To reveal the ideal timing for delayed replantation of periodontally involved teeth, the healing process of extraction sockets after extraction of periodontitis-induced teeth in rats was evaluated. Methods: Twenty-eight rats were randomly divided into two groups: a control group (n=8) and test group (n=20). In the test group, periodontitis was induced by a ligature around the cervix of the mandibular first molar of all of the rats. Two weeks later, the mandibular first molars were extracted in all of the animals. The animals were sacrificed on days 0, 3, 7, and 10 after extraction and histological and immunohistochemical analysis was performed. Results: In histological analysis of the test group, inflammatory cell infiltrate was found abundantly in the remaining periodontium 3 days after tooth extraction and decreased gradually at later time points. In immunohistochemical analysis of the test group, both interleukin-6 (IL-6) and, tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) were numerous in the furcation area at each postextraction day. IL-6 was stained more heavily between 3 and 7 days after extraction; at day 10 after extraction, little staining was observed. TNF-${\alpha}$ staining was more intense at 3 days after extraction and gradually weakened at later points in time. Conclusions: Within the limits of this study, it takes at least 10 days to resolve periodontal inflammation in rat extraction sockets.

• Journal of Periodontal and Implant Science
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• v.30 no.4
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• pp.869-885
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• 2000

Fibroblasts are major cellular components of gingiva and periodontal ligament. They regulate the healing process after surgery or injury. Recently, many natural medicines, whose advantages are less side effects and possibility of long-term use, have been studied for their capacity, their anti-bacterial and anti-inflammatory effects and regenerative potential of periodontal tissues. Sophorae radix have been traditionally used as an anti-bacterial and antiinflammatory drug in oriental medicine. The purpose of present study was to investigate the effects of Sophorae radix extract on cell cycle progression and its molecular mechanism in human gingival fibroblasts. Sophorae radix extracts($100{\mu}g/ml$) notably increased cell proliferation and cell activity in the human gingival fibroblasts as compared to non-supplemented controls. There was an increase in the S phase and a decrease in the G1 phase in $100{\mu}g/ml$ of Sophorae radix extracts group as compared to non-supplemented controls. The level of cyclin E and cdk 2 protein in test group was higher than that of control groups. But that of cyclin D, cdk 4, and cdk 6 was not distinguished from controls. The level of p53 protein in test group was lower than that of controls, whereas that of p21 was not different. The level of pRB protein in test group was higher than that of controls, whereas that of p16 was lower. These results indicate that the increase of cell proliferation by Sophorae radix extracts may be due to the increased expression of cyclin E and cdk 2, and the decreased expression of p53 and p16 in human gingival fibroblasts.

• Journal of Periodontal and Implant Science
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• v.28 no.2
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• pp.309-320
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• 1998

The periodontal health has been evaluated clinically by various epidemiological indices, and in researches by measurement of gingival crevicular fluid. Laser Doppler flowmetry is a reliable and objective method that allows immediate measurement of erythrocyte flux in approximately one cubic mm of the capillary bed without disturbing the tissues. The purpose of the present study was to determine whether human gingival blood flow was different according to measuring area, measuring time, and sex or not. Forty volunteers with good general and periodontal health, aged early twenties and unmarried, were selected. Laser Doppler flowmetry($floLAB^{(R)}$, Moor Instruments Ltd., England) was applied to measure the gingival blood flow of marginal gingiva, interdental papilla, attached gingiva and alveolar mucosa. The blood flow of interdental papilla was measured at 9-10 AM, 1-2 PM, and 5-6 PM. The difference of blood flow according to measuring area and measuring time was statistically analyzed by one way AOVA and Dunkan test, and the difference of blood flow between men and women was statistically analyzed by t-test. (1) Mean blood flow was significantly higher in alveolar mucosa than in the gingiva(p<0.05), and there was no significant difference in blood flow between marginal gingiva and interdental papilla(p>0.1). (2) Mean blood flow was significantly higher at 5-6 PM than at 9-10 AM and 1-2 PM(p<0.05). But there was no significant difference in gingival blood flow between 9-10 AM and 1-2 PM(p>0.1). (3) There was no significant difference in gingival blood flow between men and women(p>0.1). The above results suggest that the measurment of gingival blood flow using laser Doppler flowmetry may be clinically applicable to early determination of gingival inflammation and evaluation of healing status, but further studies are necessary to standardize and simplify the measuring procedure.

• Journal of Periodontal and Implant Science
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• v.28 no.2
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• pp.291-310
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• 1998

This study was performed to evaluate the effects of extracts of Drynariae Rhizoma on the characteristics of rat calvaria cells(RCV) and bone marrow cells(RBM) which have the important role on the bone formation in vitro. Drynariae Rhizoma has been known as the useful herbal medicament for treatment of the wound healing including regeneration of bone fracture, and also has been used to treat the periodontal lesions, tooth mobility, gingival bleeding and pus discharge via sulcus in Oriental Medicine. In control group, the cells were cultured alone with Dulbeco's Modified Eagle's Medium contained with 10% fetal bovine serum, 100U/ml penicillin, $100{\mu}g/ml$ streptomycin, $0.5{\mu}g/ml$ amphotericin-B. In experimental group, extracts of Drynariae Rhizoma(0.1, 1, 5, 10, $50{\mu}g/ml$) were added into the above culture condition. And then each group was characterized by examing the cell proliferation at 1, 3, 7, 14, 21, 30th day, the amount of total protein synthesis and alkaline phosphatase activity of RCV at 2,4th day and those of RBM at 3, 6th day. And also, the calcified nodule of RCV was examed at 3, 5th day in three goup, control, experimental, culture with the PDGF group. The results were as follow ; 1. Both RCV and RBM cells in Drynariae Rhizoma-treated experimental group proliferated more rapidly than nontreated control group. The experimental group below $5{\mu}g/ml$ Drynariae Rhizoma-treated showed more prominent cell proliferation from the 7th day to the 21st day than the control group and above $10\;{\mu}g/ml$ treated group in RCV. 2. Amount of total protein synthesis was more increased in Drynariae Rhizomatreated group than in control group. In $5{\mu}g/ml$ Drynariae Rhizoma-treated group showed most prominent protein synthesis of the any other exrperimental group and control group. 3. Alkaline phosphatase activity also more increased in Drynariae Rhizomatreated group than control group. 4. Mineralized nodules in Drynariae Rhizoma-treated group were more than not in control group but also in PDGF-treated group. From the above results, Drynariae Rhizoma appeared to enhanced the proliferation, protein synthesis, alkaline phosphatase activity and cellular ability of mineralized nodule formation than PDGF. So that, we conclude that Drynariae Rhizoma enhances the activities of bone cells which have the important role on the periodontal regeneration and optimal application of Drynariae Rhizoma was thought to be useful as the means in bone regeneration.

• Journal of Periodontal and Implant Science
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• v.40 no.5
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• pp.232-238
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• 2010

Purpose: To prolong the degradation time of collagen membranes, various cross-linking techniques have been developed. For cross-linking, chemicals such as formaldehyde and glutaraldehyde are added to collagen membranes, but these chemicals could adversely affect surrounding tissues. The aim of this study is to evaluate the ability of porous non-chemical cross-linking porcine-derived collagen nanofibrous membrane to enhance bone and associated tissue regeneration in one-wall intrabony defects in beagle dogs. Methods: The second and third mandibular premolars and the first molars of 2 adult beagles were extracted bilaterally and the extraction sites were allowed to heal for 10 weeks. One-wall intrabony defects were prepared bilaterally on the mesial and distal side of the fourth mandibular premolars. Among eight defects, four defects were not covered with membrane as controls and the other four defects were covered with membrane as the experimental group. The animals were sacrificed 10 weeks after surgery. Results: Wound healing was generally uneventful. For all parameters evaluating bone regeneration, the experimental group showed significantly superior results compared to the control. In new bone height (NBh), the experimental group exhibited a greater mean value than the control ($3.04{\pm}0.23\;mm/1.57{\pm}0.59$, P=0.003). Also, in new bone area (NBa) and new bone volume (NBv), the experimental group showed superior results compared to the control (NBa, $34.48{\pm}10.21%$ vs. $5.09{\pm}5.76%$, P=0.014; and NBv, $28.04{\pm}12.96$ vs. $1.55{\pm}0.57$, P=0.041). On the other hand, for parameters evaluating periodontal tissue regeneration, including junctional epithelium migration and new cementum height, there were no statistically significant differences between two groups. Conclusions: Within the limitations of this study, this collagen membrane enhanced bone regeneration at one-wall intrabony defects. On the other hand, no influence of this membrane on periodontal tissue regeneration could be ascertained in this study.

• Journal of Periodontal and Implant Science
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• v.31 no.2
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• pp.489-499
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• 2001

Bone graft and guided tissue regeneration have been used for the regeneration of periodontal tissue which is the ultimate goal of periodontal treatment. Recently, it was reported that some kind of growth factors were used for regeneration. Platelet rich plasma was researched that it could increase the density of bone and the rate of bone regeneration. For that, 25 patients which have pocket depth more than 5mm at any of 6 surfaces, of healthy patient without any systemic disease were treated. $Biogran^{?}$ Were grafted into 14 infrabony pockets as controls, and $Biogran^{(R)}$ with PRP were inserted into 31 infrabony pockets. And then, follwing evaluations were made at the end of 1, 3 and 6 months. 1. There was no statistical difference between control and experimental group in pocket depth, gingival recession, minimum probing attachment level and maximum probing attachment level at preoperation(p>0.05). 2. Decrease in probing pocket depth were reduced to 3.32mm for experimental group and 2.71mm for control group. The decrease was evident at the end of 1 month, they were 2.97mm and 2.29mm,and it was statistically difference(p<0.05). 3. Gingival recession was increased by 0.55mm in experimental group and 0.50mm in control group, it was evident at the end of 1 month. And it was statistically difference(p<0.05). 4. Minimum probing attachment level was increased by 0.35mm in experimental group and 0.36mm in control group, it was statistically difference(p<0.05). 5. Maximum probing attachment level was decreased by 3.19mm in experimental group and 2.93mm in control group, it was statistically difference(p<0.05). 6. There was no statistical difference between control and experimental group in pocket depth, gingival recession, minimum probing attachment level and maximum probing attachment level(p>0.05). There was statistical difference in decrease of pocket depth between pre-operation and 1 month after post-operation(p<0.05). In conclusion, bone graft using $Biogran^{?}$ and bone graft using $Biogran^{?}$ With platelet rich plasma were both effective in treatment of infrabony pocket, bone graft using $Biogran^{?}$ With platelet rich plasma was more effective in early soft tissue healing.

• Journal of dental hygiene science
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• v.23 no.4
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• pp.282-295
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• 2023

Background: Secretory leukocyte protease inhibitor (SLPI) protects tissues from proteases and promotes cell proliferation and healing. SLPI also reduces periodontal inflammation and alveolar bone resorption by inhibiting proinflammatory cytokine expression in rat periodontal tissues and osteoblasts. However, little is known of the role of SLPI in the expression of osteoclast regulatory factors from osteoblasts, which are crucial for the interaction between osteoblasts and osteoclasts. Therefore, we aimed to determine the effects of SLPI on the regulation of osteoclasts and osteoblasts in LPS-treated alveolar bone and osteoblasts. Methods: Periodontitis was induced in rats using LPS. After each LPS injection, SLPI was injected into the same area. Immunohistochemical analysis was performed with antibodies against SLPI, RANKL, OPG, and Runx2 in the periodontal tissue. RT-PCR and western blotting were performed to determine the expression levels of SLPI, RANKL, OPG, and Runx2 in LPS- and SLPI/LPS-treated MC3T3-E1 cells. SLPI/LPS-treated MC3T3-E1 cells were also stained with Alizarin Red S. Results: Immunohistochemical analysis showed that the expression levels of SLPI, OPG, and Runx2 were higher while that of RANKL was lower in the LPS/SLPI group relative to those in the LPS group. The mRNA and protein expression of SLPI, OPG, and Runx2 was higher in SLPI/LPS/MC3T3-E1 cells than in LPS/MC3T3-E1 cells, and RANKL expression was lower. During differentiation, OPG and Runx2 protein levels were higher whereas RANKL levels were lower in SLPI/LPS/MC3T3-E1 than in LPS/MC3T3-E1 cells on days 0, 4, 7, and 10. In addition, mineralization and matrix deposition were higher in SLPI/LPS/MC3T3-E1 than in LPS/MC3T3-E1 on days 7 and 10. SLPI decreased RANKL expression in LPS-treated alveolar bone and osteoblasts but increased the expression of OPG and Runx2. Conclusion: SLPI can be considered as a regulatory molecule that indirectly regulates osteoclast activation via osteoblasts and promotes osteoblast differentiation.

• Journal of Periodontal and Implant Science
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• v.39 no.3
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• pp.367-373
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• 2009

Purpose: Following tooth extraction caused by severe periodontitis, alveolar ridge dimension lose their original volume. To reduce the alveolar ridge dimension, the ridge preservation technique has been introduced and tested in many clinical studies with membrane alone or membrane plus graft, achieving reduced ridge loss compared to extraction only. The aim of the present clinical study was to compare the post-extraction dimensional changes in the membrane exposure group to non-exposure group during healing period following ridge preservation technique. Methods: Ridge preservation was performed in 44 extraction sites. After extraction, deproteinized bovine bone mineral coated with synthetic oligopeptide (Ossgen-$X15^{(R)}$) or deproteinized bovine bone mineral (Bio-$Oss^{(R)}$) was implanted into the socket. A collagen membrane (Bio-$Gide^{(R)}$) was trimmed to cover the socket completely and applied to the entrance of the socket. Four clinical parameters were compared between baseline and 6 months. Results: During healing period, membrane exposure was observed at 19 sites. At the re-entry, hard newly formed tissue were observed at the ridge preservation site. The grafted socket sites were well preserved in their volume dimension. In both groups, horizontal ridge width was reduced and vertical height was increased. There were not statistically significant differences in horizontal (-1.32 mm vs -1.00 mm) and vertical ridge change (2.24 mm vs 2.37 mm at buccal crest, 1.36 mm vs. 1.53 mm at lingual crest) between two groups. Conclusions: The ridge preservation approach after tooth extraction effectively prevented resorption of hard tissue ridge in spite of membrane exposure during healing period.

• Journal of Periodontal and Implant Science
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• v.29 no.1
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• pp.233-249
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• 1999

Primary fixation is one of the most important factor in establishing adequate osseointegration between implant and bone. To evaluate the initial healing response of bone around implants without primary bone contact, this study was designed to create considerable space between implant and bone in 5 mongrel dogs, about 1-year old. After 3 holes of 6.0mm in diameter were prepared at the femur neck of the dogs, commercially pure titanium thread type implants(STERI-$OSS^{(R)}$), 8mm in length and 3.8mm, 5.0mm and 6.0mm in diameter, were inserted. Implants were supported by only nonresorbable membrane($Teflon^{(R)}$), and the penetration of upper soft tissue into the gap was inhibited by it. The each implant was positioned in the center of the drilled hole. 9 implants with different diameters were inserted in 3 dogs for histologic observation, and 12 were inserted in 2 dogs for mobility test and removal torque test.Fluorescent dyes were injected in order of Doxycycline, Alizarin Red S, and Calcein at intervals of 2 weeks. At 4-, 8-, and 12-week after placement, 3 dogs were sacrificed for histologic observation, and at 8- and 12-week after placement, 2 dogs were sacrificed for mobility test using $Periotest^{(R)}$ (Simens AG, Bensheim, Germany) and torque test using Autograph AGS-1000D $series^{(R)}$(Japan). The result were as follows: 1. The wider the gap between bone and implant was, the less bone maturity was, and the later osseointegration was occurred. Trabecular direction of new bone around implant was changed from parallel to perpendicular to the implant, and the gap was filled with new bone, over time. 2. There was a decreasing tendency over time in the mobility of all implants, but the wider gap between bone and implant was, the smaller decrease of the mobility was. 3. There was a increasing tendency over time in the removal torque gauge of all implants, and the wider gap was, the smaller increase of the removal torque gauge was. The results suggest that osseointegration in case of implant without primary bone contact may be obtained by guided bone regeneration technique with prolonged healing period, but the time of second surgery should be considered carefully.

• Journal of Periodontal and Implant Science
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• v.40 no.3
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• pp.132-138
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• 2010

Purpose: The purpose of this study was to compare the bone regeneration effects of cortical, cancellous, and cortico-cancellous human bone substitutes on calvarial defects of rabbits. Methods: Four 8-mm diameter calvarial defects were created in each of nine New Zealand white rabbits. Freeze-dried cortical bone, freeze-dried cortico-cancellous bone, and demineralized bone matrix with freeze-dried cancellous bone were inserted into the defects, while the non-grafted defect was regarded as the control. After 4, 8, and 12 weeks of healing, the experimental animals were euthanized for specimen preparation. Micro-computed tomography (micro-CT) was performed to calculate the percent bone volume. After histological evaluation, histomorphometric analysis was performed to quantify new bone formation. Results: In micro-CT evaluation, freeze-dried cortico-cancellous human bone showed the highest percent bone volume value among the experimental groups at week 4. At week 8 and week 12, freeze-dried cortical human bone showed the highest percent bone volume value among the experimental groups. In histologic evaluation, at week 4, freeze-dried cortico-cancellous human bone showed more prominent osteoid tissue than any other group. New bone formation was increased in all of the experimental groups at week 8 and 12. Histomorphometric data showed that freeze-dried cortico-cancellous human bone showed a significantly higher new bone formation percentile value than any other experimental group at week 4. At week 8, freeze-dried cortical human bone showed the highest value, of which a significant difference existed between freeze-dried cortical human bone and demineralized bone matrix with freeze-dried cancellous human bone. At week 12, there were no significant differences among the experimental groups. Conclusions: Freeze-dried cortico-cancellous human bone showed swift new bone formation at the 4-week healing phase, whereas there was less difference in new bone formation among the experimental groups in the following healing phases.