• Journal of Periodontal and Implant Science
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• v.40 no.5
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• pp.220-226
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• 2010

Purpose: This study was performed to evaluate the periodontal wound healing effect of particulate equine bone mineral on canine alveolar bone defects. Methods: Twelve adult male beagle dogs were used as study subjects. The mandibular second and fourth premolars were extracted prior to the experimental surgery, and the extraction sites were allowed to heal for 8 weeks. After periodontal probing, two-walled defects were created at the mesial and distal sides of the mandibular third premolars bilaterally, and the defects were filled with equine particulate bone with collagen membrane or bovine particulate bone with collagen membrane, or collagen membrane alone. The defects without any treatment served as negative controls. After probing depth measurement, animals were sacrificed at 10, 16, and 24 post-surgery weeks for micro-computed tomographic and histomorphometric analysis. Results: The equine particulate bone-inserted group showed significantly decreased values of probing depth and first bone contact compared to the negative control and collagen membrane alone groups at weeks 10, 16, and 24 (P<0.05). There were no significant differences in the new cementum length, newly-formed bone area, or newly-formed bone volume between equine particulate bone- and bovine particulate bone-inserted groups, both of which showed significantly increased values compared to the negative control and collagen membrane alone groups (P<0.05). Conclusions: Equine particulate bone showed significant differences in probing depth, first bone contact, new cementum length, newly formed bone area, and bone volume fraction values when compared to the negative control and collagen membrane alone groups. There were no significant differences between equine and bovine particulate bone substitutes in these parameters; therefore, we can conclude that equine particulate bone is equivalent to bovine bone for periodontal regeneration.

• Journal of Korean Dental Science
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• v.16 no.2
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• pp.172-181
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• 2023

Purpose: To investigate the effect of epidermal growth factor (EGF) with collagen matrix (CM) for increasing gingival thickness. Materials and Methods: In five mongrel dogs, bilateral gingival defects were surgically made on the maxillary canines. After two months, either a subepithelial connective tissue graft (group SCTG) or CM with EGF (0.1 ug/ml, group EGF) was grafted, and the flap was coronally positioned to cover the graft materials. The animals were sacrificed after three months. Intraoral scanning was performed for soft tissue analysis. Histologic and histomorphometric analyses were performed. Result: Two animals exhibited wound dehiscence during the healing phase, leaving three for analysis. No statistically significant difference was found in soft tissue changes (P>0.05). The level of gingival margin (GM) increased in both groups (1.02±0.74 mm in group SCTG vs. 1.24±0.83 mm in group EGF). Linear increases at the GM pre-augmentation in the soft tissue profile were 1.08±0.58 mm in group SCTG and 0.96±0.73 mm in group EGF. Histomorphometric parameters (keratinized tissue height, tissue thickness, and rete peg density) were not significantly different between the groups (P>0.05). Conclusion: EGF loaded onto CM led to comparable gingival phenotype enhancement to SCTG.

• Journal of Periodontal and Implant Science
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• v.53 no.5
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• pp.321-335
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• 2023

Purpose: The aim of this study was to investigate the efficacy of photo-crosslinked gelatin methacryloyl (GelMa) hydrogel containing calcium phosphate nanoparticles (CNp) when applying different fabrication methods for bone regeneration. Methods: Four circular defects were created in the calvaria of 10 rabbits. Each defect was randomly allocated to the following study groups: 1) the sham control group, 2) the GelMa group (defect filled with crosslinked GelMa hydrogel), 3) the CNp-GelMa group (GelMa hydrogel crosslinked with nanoparticles), and 4) the CNp+GelMa group (crosslinked GelMa loaded with nanoparticles). At 2, 4, and 8 weeks, samples were harvested, and histological and micro-computed tomography analyses were performed. Results: Histomorphometric analysis showed that the CNp-GelMa and CNp+GelMa groups at 2 weeks had significantly greater total augmented areas than the control group (P<0.05). The greatest new bone area was observed in the CNp-GelMa group, but without statistical significance (P>0.05). Crosslinked GelMa hydrogel with nanoparticles exhibited good biocompatibility with a minimal inflammatory reaction. Conclusions: There was no difference in the efficacy of bone regeneration according to the synthesized method of photo-crosslinked GelMa hydrogel with nanoparticles. However, these materials could remain within a bone defect up to 2 weeks and showed good biocompatibility with little inflammatory response. Further improvement in mechanical properties and resistance to enzymatic degradation would be needed for the clinical application.

• Journal of Periodontal and Implant Science
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• v.29 no.3
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• pp.519-540
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• 1999

The purpose of this study is to compare the healing aspects of the use of ePTFE membrane alone versus combination treatment of ePTFE membrane and bone grafts on class II furcation defects. Seventeen defects were applied ePTFE membrane alone on mxillary molar buccal class II furcation defects as Group I, seventeen defects were applied ePTFE membrane and bone grafts on maxillary molar buccal class II furcation defects as Group II, twenty-three defects were applied ePTFE membrane alone on mandibular molar buccal class II furcation defects as Group III, twenty defects were applied ePTFE membrane and bone grafts on mandibular molar buccal class II furcation defects as Group IV . Measurements were made to determine clinical attachment level, probing depth, gingival depth, SBI, mobility at baseline, 3, 6, 12 months postoperatively. Additional measurements were made to determine membrane exposure level at surgery, 1, 2, 6 weeks postoperatively. And then healing patterns and postoperative complications were evaluated. The result as follows : There were statistically significant differences in probing depth reduction, clinical attachment gain, mobility reduction at values of 3, 6, 12 months postoperatively compared to values of baseline(p<0.05), whereas no significant differences in SBI and gingival recession. In group II, membrane exposure level was increased at 1, 2, 6 weeks postoperatively compared to value of baseline(p<0.05). There were statistically significant differences in changes of probing depth at 3, 6, 12 months postoperatively in combination groups of ePTFE membrane and bone graft compared to groups of ePTFE membrane alone(p<0.05). The vast majority of cases fall into typical healing and delayed healing response when membranes were removed in all groups. Pain and swelling were common postoperative complications. In conclusion, this study was showed more effective healing aspects in combination treatment of ePTFE membrane and bone graft than ePTFE membrane alone and on mandibular molar class II furcation defects than maxillary molar.

• Journal of Periodontal and Implant Science
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• v.26 no.4
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• pp.823-840
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• 1996

The purpose of this study was to evaluate the effect of dexamethasone on the healing aspect of gingiva and alveolar bone after extraction. Extracted socket of 24 Sprague-Dawley rat was used. To extract easily and minimize injury, ${\beta}-APN$ 0.2g/kg/day soluted in mineral water was administrated for 5 days before extraction in both group. Ampicillin 1.5ml/kg i.m.,q.d, was administered for preventing infection after teeth extraction in both group, and dexamethasone 0.2mg/kg/day was injected for 3 days in experimental group.3 rats on each day was sacrificed on 1, 3, 7, 15 days after extraction. Histologic examination and the activity of osteoclasts by tartrate resistant acid phosphatase was observed. The results were as follows : 1. The Overall healing pattern was similar with both the experimental and control group, but in experimental group osseous healing was delayed. 2. The activity of osteoclasts was increased to day 3 and then decreased after day 3 in the experimental group. In comparison to the control group, the experimental group showed increased appearance to day 7 and then decreased appearance following day. 3. Regarding to the change of osseous tissue, the activity of osteoblasts was shown at day 7,but osteoclastic activity of the experimental group was less than that of the control group. The osteoclastic activity was statistically significant between two groups except day 7(p<0.05, p<0.01). In conclusion, the effects of dexamethasone for healing of extraction socket were considered as limiting the activity of osteoclasts, and the healing of extraction socket was delayed.

• Journal of Periodontal and Implant Science
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• v.42 no.5
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• pp.166-172
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• 2012

Purpose: The aim of this study was to evaluate the improvement of osteogenic potential of biphasic calcium phosphate (BCP) bone substitute coated with synthetic cell-binding peptide sequences in a standardized rabbit sinus model. Methods: Standardized 6-mm diameter defects were created bilaterally on the maxillary sinus of ten male New Zealand white rabbits, receiving BCP bone substitute coated with synthetic cell binding peptide sequences on one side (experimental group) and BCP bone substitute without coating (control group) on the other side. Histologic and histomorphometric analysis of bone formation was carried out after a healing period of 4 or 8 weeks. Results: Histological analysis revealed signs of new bone formation in both experimental groups (4- and 8-week healing groups) with a statistically significant increase in bone formation in the 4-week healing group compared to the control group. However, no statistically significant difference in bone formation was found between the 8-week healing group and the control group. Conclusions: This study found that BCP bone substitute coated with synthetic cell-binding peptide sequences enhanced osteoinductive potential in a standardized rabbit sinus model and its effectiveness was greater in the 4-week healing group than in the 8-week healing group.

• Animal cells and systems
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• v.16 no.6
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• pp.469-478
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• 2012

Sex hormones have long been considered to play an important role in bone turnover rate, periodontal diseases, and wound healing. We have studied the effect of porcine testis steroid extract (PTSE), an extract of porcine testes, which holds a good ratio of 19-nortestosterone (nandrolone), testosterone, androstenedione, $17{\beta}$-estradiol, and estrone, on the healing rate of a standardized full-thickness linear wound on the back of the rat. Skin punch or carbon dioxide ($CO_2$) laser methods were used to create the deep skin injury in two groups of animals. The animals were treated with the PTSE cream, control cream and Vaseline (control) to find out the effect in re-epithelialization, contraction, and formation of granulation and scar tissues. Histological examination after 21 days showed 100, 87.4, and 80.5% recovery of epidermis, dermis, and hypodermis, respectively in the PTSE-treated animals. Similarly, on the 15th day of treatment, complete healing of intact skin was observed in the PTSE cream-treated animals among the laser radiation group. Even though the beginning of re-epithelialization phase and completion of serum crust formation was also observed in the base cream- and Vaseline-treated animals respectively, the complete healing cycle was observed only in the PTSE-treated group. The white blood cell count in the PTSE-treated group showed that PTSE cream is nontoxic to animals.

• Journal of Periodontal and Implant Science
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• v.31 no.2
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• pp.357-369
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• 2001

In this present study, the healing process and the recurrence of pigmentation were evaluated clinically and histologically in accordance with the extent and the range of pigmentation after phenol was applied to remove melanin pigmentation in gingiva. Six mongrel dogs were used. The melanin pigmentation in canine gingiva were classified into slight, moderate and severe according to the extent of pigmentation and divided into local and diffuse types according to the range. Following general and local anesthesia, 90% phenol was applied to the pigmented gingiva of the subjects with small cotton balls until the surface was etched to be whitish and was neutralized with small cotton balls soaked by 95% alcohol. The contralateral pigmented gingiva to the one treated with phenol, was treated by surgical deepithelialization. At 1, 3 and 8 weeks, the treated gingiva was examined clinically and evaluated histologically following H-E stain, and HMB 45 stain for melanocyte after biopsy. In the phenol treated sites, epithelium and connective tissue healed normally and there was no pigmentation at 1 week. At 3 weeks of healing, melanin repigmentation was observed in the severe local type and moderate to severe diffuse type. In the surgically deepithelialized sites, healing was delayed, compared to phenol treated sites and the infiltration of the inflammatory cells and congestion in connective tissue was shown at 1 week. At 3 weeks, healing was completed and there was a partial melanin repigmentation. At 8 weeks of healing, the extent and the range of repigmentation were increased in both group according to the extent or range priot to depigmentation procedure. These results suggpriorest that the removal of melanin pigmentation with 90% phenol application result in normal healing process of gingiva. However, in the severe local type and moderate to severe diffuse type, sites treated with phenol showed repigmentation at 3 week, which was earlier than surgical deepithelialized sites. Therefore it is required to select appropriate method according to initial condition of pigmentation.

• Journal of Periodontal and Implant Science
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• v.26 no.4
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• pp.841-858
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• 1996

Epidermal growth factor(EGF) is one of polypeptide growth factors. EGF has been reported as a biological mediator which regulates activities of wound healing process including the cell proliferation, migration and metabolism. The purposes of this study is to evaluate the effects of EGF on the human periodontal ligament cells and human gingival fibroblast cells that promote regeneration of periodntal tissue. The mitogenic effects of epidermal growth factor on human periodontal ligament cells and human gingival fibroblasts were evaluated by determining the incorporation of 5-Bromo-2'-deoxy-uridine into DNA of the cells in a dose dependent manner. The prepared cells were the primary cultured gingival fibroblast and periodontal ligament cells from humans, the fourth or sixth subpassages were used in the experiments. Cells were seeded in DMEM containing 10% FBS. 1, 10, 50, 100, $200{\eta}g/ml$ and epidermal growth factor were added to the quiescent cells for 24 hours, 48 hours and 72 hours. They were labeled with $10\{mu}l/200{\mu}l$ 5-Bromo-2'-deoxy-uridine for the last 6 hours of each culture. The results of the five determinants were presented as mean and S.D.. The results were as follows : The DNA synthetic activity of human gingival fibroblasts were increased dose dependently by epidermal growth factor at 24 hours, 48 hours and 72 hours. The mitogenic effects were similar at the 24 and 48 hours of epidermal growth factor, but the DNA synthetic activity of human gingival fibroblasts generally decreased at 72 hours. The DNA synthetic activity of human periodontal ligament cells were increased dose dependently by epidermal growth factor at 24 hours but the DNA synthetic activity decreased at $200{\eta}g/ml$ of each hour. Generally the maximum mitogenic effects were observed at the 48 hours application of epidermal growth factor. The DNA synthetic activity of human periodontal ligament cells generally decreased lower at 24, 72 hours than at 48 hours the application of epidermal growth factor. In the comparison of DNA synthetic activity between human gingival fibroblasts and human periodontal ligament cells, human periodontal ligament cells had slightly higher proliferation activity than human gingival fibroblasts for a longer time at the high dosage of the epidermal growth factor. In conclusion, epidermal growth factor have important roles in the stimulation of DNA synthesis in human periodontal ligament cells and human gingival fibroblasts, and thus may be useful for clinical applications in periodontal regenerative procedures.

• Journal of Periodontal and Implant Science
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• v.29 no.4
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• pp.821-838
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• 1999

On the basis of the evidences that electrical stimulation could enhance proliferation and differentiation of bone cells and promote healing and regeneration of bone, this study was performed to investigate the effects of electrical stimulation on human periodontal ligament cells and gingival fibroblasts in vitro, which also have important roles in regeneration of periodontium, and to evaluate the potential of clinical application of electrical stimulation. Human periodontal ligament cells and gingival fibroblasts were primarily cultured from the root surface of extracted premolar and the adjacent gingiva without periodontal diseases. In control group, the cells ($5{\times}10^4$ cells/ml)were incubated only in Dulbecco's Modified Eagle's Medium contained with 10% fetal bovine serum. In test groups, electrical stimulation was given at the current intensity of $0.25{\mu]A$(test group 1), $1.0{\mu}A$(test group 2), and $2.5{\mu}A$(test group 3) for 12 hours to the same culture media with the control group. After 12 hour exposure of electrical stimulation, the cells were incubated for 2 and a half days(60 hours), and then each group of cells was analyzed for cell proliferation, protein level, and activity of alkaline phosphatase. The results were as follows ; 1. The Rate of cell proliferation of every test group increased significantly in both periodontal ligament cells and gingival fibroblasts, and in periodontal ligament cells, test group 3 showed significantly increased proliferation compared to the other test groups(p<0.05). 2. In the protein levels, neither periodontal ligament cell nor gingival fibroblast showed statistically significant differences between control and test groups. 3. The activity of alkaline phosphatase in periodontal ligament cells increased significantly in all test groups(p<0.05), but there were no significant differences between 3 test groups. In gingival fibroblasts, the activity of alkaline phosphatase increased significantly only in test group 3(p<0.05). From the above results, it is concluded that electrical stimulation may have beneficial effects on the regeneration of destructed periodontal tissue in regard of the stimulation of periodontal ligament cells and gingival fibroblasts as well as electrically stimulated bone formation that has been known, and that electrical stimulation may have the potential of clinical application.