• Restorative Dentistry and Endodontics
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• v.16 no.2
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• pp.165-173
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• 1991

The purpose of the present study was to measure and compare the arachidonic acid metabolites in diseased periodontal tissue and vital pulp tissue of the tooth, and to investigate the relationship between periodontal and pulp disease. Diseased periodontal tissue of periodontally involved human teeth and vital pulp tissue from the same teeth which were intact with no periapical lesions were obtained. Each periodontal and pulp tissue homogenates from the same tooth were incubated with $^{14}C$ - arachidonic acid. Lipid solvent extracts were separated by thin layer chromatography to be analyzed by autoradiography and TLC analyzer. 1. The conversion into $TXB_2$, 6 - keto - $PGF_{1a}$ and $PGE_2$, and unidentified metabolite in pulp tissue were less than that in diseased periodontal tissue(P<0.05). 2. Biosynthetic levels of $TXB_2$, unidentified metabolite, 6 - keto - $PGF_{1a}$ and HETEs were not satistically significant between diseased periodontal tissue and pulp tissue. $LTB_4$ was measured highly in pulp tissue(P<0.1). 3. The percentage of each metabolite to the total converted metabolites were not statistically significant between diseased periodontal tissue and pulp tissue. But the percentage of $LTB_4$ in pulp tissue was higher than that in diseased periodontal tissue(P<0.05). 4. The relative amounts of the total metabolites formed in lipoxygenase pathway to those formed in cyclo - oxygenase pathway were 6 fold in diseased periodontal tissue and 12 fold in pulp tissue. But there was no statistical significance between diseased periodontal tissue and pulp tissue(P>0.05).

• Journal of Periodontal and Implant Science
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• v.40 no.2
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• pp.49-55
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• 2010

Purpose: The purpose of this study was to preliminarily evaluate the influence of diabetes mellitus (DM) on periodontal tissue without establishment of periodontitis. Methods: Seven-week-old db/db mice were used for the diabetic experimental group and systematically healthy mice of the same age were used as controls. After 1 week of acclimatization, the animals were sacrificed for hard and soft tissue evaluation. The pattern of bone destruction was evaluated by stereomicroscope evaluation with alizarin red staining and radiographic evaluation by microscopic computerized tomography images. Histological evaluation was performed with hematoxylin and eosin stain for evaluation of soft tissue changes. Results: In both stereomicroscope evaluation and radiograph image analysis, aggressive form of bone destruction was observed in diabetic animals when compared to the systematically healthy controls. In histological evaluation, apical migration of junctional epithelium with slight inflammatory cell infiltration was observed with disarrangement of connective tissue fibers. Conclusions: Within the limits of this study, diabetic animals presented distortion in periodontal attachment and an aggressive bone loss pattern when compared to the healthy controls, suggesting that DM has an independent effect on periodontal tissue destruction irrespective of the presence or absence of periodontal disease.

• Journal of Periodontal and Implant Science
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• v.52 no.4
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• pp.298-311
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• 2022

Purpose: The aim of this study was to evaluate the clinical outcomes of periodontal granulation tissue preservation (PGTP) in access flap periodontal surgery. Methods: Twenty patients (stage III-IV periodontitis) with 42 deep periodontal pockets that did not resolve after non-surgical treatment were consecutively recruited. Access flap periodontal surgery was modified using PGTP. The clinical periodontal parameters were evaluated at 9 months. The differences in the amount of granulation tissue width (GTw) preserved were evaluated and the influence of smoking was analyzed. Results: GTw >1 mm was observed in 97.6% of interproximal defects, and the granulation tissue extended above the bone peak in 71.4% of defects. At 9 months, probing pocket depth reduction (4.33±1.43 mm) and clinical attachment gain (CAG; 4.10±1.75 mm) were statistically significant (P<0.001). The residual probing depth was 3.2±0.89 mm. When GTw extended above the interproximal bone peak (i.e., the interproximal supra-alveolar granulation tissue thickness [iSUPRA-GT] was greater than 0 mm), a significant CAG was recorded in the supra-alveolar component (1.67±1.32 mm, P<0.001). Interproximal gingival recession (iGR) was significant (P<0.05) only in smokers, with a reduction in the interdental papillary tissue height of 0.93±0.76 mm. In non-smokers, there was no increase in the iGR when the iSUPRA-GT was >0 mm. The clinical results in smokers were significantly worse. Conclusions: PGTP was used to modify access flap periodontal surgery by preserving affected tissues with the potential for recovery. The results show that preserving periodontal granulation tissue is an effective and conservative procedure in the surgical treatment of periodontal disease.

• Journal of Periodontal and Implant Science
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• v.41 no.2
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• pp.73-78
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• 2011

Purpose: For periodontal tissue engineering, it is a primary requisite and a challenge to select the optimum types of cells, properties of scaffold, and growth factor combination to reconstruct a specific tissue in its natural form and with the appropriate function. Owing to fundamental disadvantages associated with using a two-dimensional substrate, several methods of seeding cells into three-dimensional scaffolds have been reported and the authors have asserted its usefulness and effectiveness. In this study, we explore the cell attachment of periodontal ligament fibroblasts on nanohydroxyapatite (n-HA) scaffold using avidin biotin binding system (ABBS). Methods: Human periodontal ligament fibroblasts were isolated from the health tooth extracted for the purpose of orthodontic procedure. HA nanoparticles were prepared and $Ca(NO_3)_2-_4H_2O$ and $(OC_2H_5)_3P$ were selected as precursors of HA sol. The final scaffold was 8 mm in diameter and 3 mm in height disk with porosity value of 81.55%. $1{\times}10^5$ periodontal ligament fibroblasts were applied to each scaffold. The cells were seeded into scaffolds by static, agitating and ABBS seeding method. Results: The number of periodontal ligament fibroblasts attached was greater for ABBS seeding method than for static or agitating method (P<0.05). No meaningful difference has been observed among seeding methods with scanning electron microscopy images. However, increased strength of cell attachment of ABBS could be deduced from the high affinity between avidin and biotin ($Kd=10^{-15}\;M$). Conclusions: The high-affinity ABBS enhances the ability of periodontal ligament fibroblasts to attach to three-dimensionally constructed n-HA scaffold.

• Journal of Periodontal and Implant Science
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• v.42 no.2
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• pp.50-58
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• 2012

Purpose: This study evaluated histologically the tissue responses to and the effects of a customized nano-hydroxyapatite (n-HA) block bone graft on periodontal regeneration in a one-wall periodontal-defect model. Methods: A customized block bone for filling in the standardized periodontal defect was fabricated from prefabricated n-HA powders and a polymeric sponge. Bilateral $4{\times}{\times}4{\times}5$ mm (buccolingual width${\times}$mesiodistal width${\times}$depth), one-wall, critical-size intrabony periodontal defects were surgically created at the mandibular second and fourth premolars of five Beagle dogs. In each dog, one defect was filled with block-type HA and the other served as a sham-surgery control. The animals were sacrificed following an 8-week healing interval for clinical and histological evaluations. Results: Although the sites that received an n-HA block showed minimal bone formation, the n-HA block was maintained within the defect with its original hexahedral shape. In addition, only a limited inflammatory reaction was observed at sites that received an n-HA block, which might have been due to the high stability of the customized block bone. Conclusions: In the limitation of this study, customized n-HA block could provide a space for periodontal tissue engineering, with minimal inflammation.

• Journal of Periodontal and Implant Science
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• v.37 no.1
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• pp.53-64
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• 2007

The aim of this study was to examine the possibility of periodontal ligament regeneration when autotransplantation was used by the periodontal ligament fibroblasts cultured on the acellular dermal matrix in teeth without a periodontal ligament. One minipig was used in this study. The mandibular and maxillary permanent incisors were ex-tracted for the culture of the periodontal ligament cells. The roots of the unextracted teeth were classified into a positive control group, in which the normal periodontal ligament was preserved. The roots of the extracted teeth were divided into the following two groups: The negative control group, in which the periodontal ligament had been removed and the acellular dermal matrix was not applied; and an experimental group, in which the periodontal ligament had been removed and periodontal ligament fibroblast cultured on an acellular dermal matrix was applied. The prepared teeth were transplanted, and completely submerged using physical barrier membranes. The animal was sacrificed 4 weeks after the autotransplant. The transplanted teeth were examined histologically. In this study, the periodontal ligament was normal in the positive control group, and ankylosis was discovered on the denuded root surface in the negative control group. Periodontal ligament-like connective tissue was found adjacent to the denuded root and the new cementum-like layer of hard tissue was formed in the experimental group. These results suggest that the periodontal ligament fibroblasts cultured on the acellular dermal matrix may play a role in regenerating the periodontal ligament-like tissue with new cememtum-like tissue formation.

• Journal of Periodontal and Implant Science
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• v.25 no.2
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• pp.438-457
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• 1995

The origin of fibroblasts, their proliferative activity and roles in the early stages of periodontal regeneration were investigated in order to better understand the periodontal healing process in furcation defects of the beagle dog after guided tissue regeneration. Newly divided cells were identified and quantitated by immunolocalization of bromodeoxyuridine (BrdU) injected 1 hour prior to sacrificing the animals. The results were as follows :1. During periodontal healing in horizontal furcation defect, three different stages, namely the granulation tissue, connective tissue, and bone formation stages, were identified on the basis of major types of cells and tissue. 2. In the early stages of periodontal regeneration, both the remaining periodontal ligament and alveolar bone compartment were the major sources. 3. The majority of BrdU-labeled fibroblasts were located at the following areas ; 1) the coronal zone of the defect in case of the connective tissue fanned on the root surface. 2) the area within an 400 ${\mu}m$ distance from the remaining bone level in case of the periodontal ligament. 3) the area within an 100 ${\mu}m$ distance from the bone surface in case of areas of active bone formation.4. The highly proliferative fibroblasts adjacent to bone surface played a major role in the formation of osteoblast precursor cells, whereas both paravascular and endosteal cells played a minor role in new bone formation, In conclusion, it was suggested that the fibroblasts in the remaining periodontal ligament and bone will play a major role in periodontal regeneration, whereas both paravascular and endosteal cells will play a minor role in new bone formation.

• Journal of Periodontal and Implant Science
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• v.23 no.1
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• pp.67-76
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• 1993

After periodontal surgery, the potential healing responses were occurred by interaction among junctional epithelium, gingival connective tissue, alveolar bone and periodontal ligament. The only cell that created periodontal regeneration was derived from periodontal ligament. The aim of the study was to evaluate the regenerative effects of the collagen membrane($collacote^{\circ}C$) and autogenous connective tissure graft with periosteum. Experimental periodontitis were created in furcation area of 4 adult dogs with bone removal and gutta percha packing. After 6 weeks later, the gutta percha was removed and experiment was performed divided by 3 groups. 1) Flap operation(control group). 2) Flap operation with collage membrane(Experimental group I). 3) Flap operation with autogenous connective tissue graft with periosteum (Experimental group II). After dogs were sacrificed after two and three weeks, specimens were prepared and stained with hematoxylin-eosin and masson-trichrome stain for light microscopic study. The results were as follows : 1. In all gruoups, connective tissue compartments were increased from two to three weeks especially in experimental group I. 2. Collagen membrane and connective tissue were increased collagen deposits of periodontal ligament. Therefore collagen fiber attached to tooth surface was seen. 3. In al experimental groups, newly forming alveolar bone was seen. 4. Collagen membrane and connective tissue were which prevented proliferation of epithelium, aided connective tissue new attachment and influenced periodontal regeneration.

• Journal of Periodontal and Implant Science
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• v.25 no.2
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• pp.321-340
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• 1995

The regeneration of destructed periodontal tissues is one of the ultimate objectives of periodontal therapy. Guided tissue regeneration technique was developed for the ideal regeneration of periodontal tissues. In order to investigate the role of fibronectin, laminin and tenascin in the regenerating process of periodontal tissues, the expanded PTFE barrier membranes(Gore Associates, USA) removed from the patients who had been treated by guided tissue regeneration(GTR) and guided bone regeneration(GBR) techniques were fixed in neutral formalin for 6-24 hours, embedded with paraffin, sectioned at $4-6{\mu}m$ in thickness, and immunohistochemically processed by Avidin-Biotin peroxidase complex method for detecting fibronectin, laminin and tenascin. Monoclonal mouse anti-human fibronectin antibody(Oncogene Science, USA., 1:100), monoclonal mouse anti-human laminin antibody(Oncogene Science, USA., 1:50) and mouse anti-human tenascin antibody(Oncogene Science, USA, 1:10) were used as primary antibodies. The light microscopic findings were as follows: (1) The distribution of fibronectin, laminin and tenascin was various according to the area of barrier membranes. (2) The distribution of fibronectin in case of GBR was extensive in the tissue on the outer surface of barrier membranes, and rare in the intervening space and on the inner surface. In case of GTR it was extensive on the outer surface and in the intervening space, and rare on the inner surface. (3) The distribution of laminin was rare in the tissue on the outer, the inner surface and intervening space of barrier membranes, regardless of GBR or GTR. (4) In case 'of GBR rare distribution of tenascin was observed on the outer surface only, except the inner surface and the intervening space of barrier membranes. In case of GTR the distribution of tenascin was extensive in the tissue on the outer surface, rare in intervening space and the inner surface. The results suggest that fibronectin, laminin and tenascin may play a important role in the regenerating process of periodontal tissue, and they may affect the outcome of healing.

• Journal of Periodontal and Implant Science
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• v.53 no.3
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• pp.207-217
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• 2023

Purpose: Non-crosslinked and crosslinked collagen membranes are known to exhibit distinct degradation characteristics, resulting in contrasting orientations of the adjacent tissues and different biological processes. The aim of this study was to conduct a histomorphometric assessment of non-crosslinked and crosslinked collagen membranes regarding neovascularization, tissue integration, tissue encapsulation, and biodegradation. Methods: Guided bone regeneration was performed using either a non-crosslinked (BG) or a crosslinked collagen membrane (CM) in 15 beagle dogs, which were euthanized at 4, 8, and 16 weeks (n=5 each) for histomorphometric analysis. The samples were assessed regarding neovascularization, tissue integration, encapsulation, the remaining membrane area, and pseudoperiosteum formation. The BG and CM groups were compared at different time periods using nonparametric statistical methods. Results: The remaining membrane area of CM was significantly greater than that of BG at 16 weeks; however, there were no significant differences at 4 and 8 weeks. Conversely, the neovascularization score for CM was significantly less than that for BG at 16 weeks. BG exhibited significantly greater tissue integration and encapsulation scores than CM at all time periods, apart from encapsulation at 16 weeks. Pseudoperiosteum formation was observed in the BG group at 16 weeks. Conclusions: Although BG membranes were more rapidly biodegraded than CM membranes, they were gradually replaced by connective tissue with complete integration and maturation of the surrounding tissues to form dense periosteum-like connective tissue. Further studies need to be performed to validate the barrier effect of the pseudoperiosteum.