• Restorative Dentistry and Endodontics
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• v.40 no.2
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• pp.166-171
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• 2015

A palato-radicular groove (PRG) is a developmental anomaly primarily found in the maxillary lateral incisors. It is a potential communication path between the root canal and the periodontium that decreases the survival prognosis of the affected tooth, therefore compromising the stability of the dental structure in the oral cavity. The aim of this case report is to present an original technique where a PRG was treated by means of intracanal disinfection, PRG sealing with glass ionomer, replantation with intentional horizontal 180 degree rotation of the tooth, and an aesthetic veneer placed to provide adequate tooth morphology. The clinical and biological benefits of this novel technique are presented and discussed.

• Proceedings of the KACD Conference
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• 2003.11a
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• pp.591-591
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• 2003

Apical periodontitis is inflammation of the periodontium caused by infection of the pulp canal system. Moreover, a dental periradicular lesion occurs as a periradicular tissue reaction to bacterial infection and consists of periradicular inflammation with alveolar bone destruction and root resorption, a consequence of the interaction between oral flora and the existing host defenses. Many investigations dealing with the pathogenesis and history of periradicular lesions have described histologically, immunologically, biochemically the development of the periradicular lesion；but none of these studies have shown any correlation between this lesion and several factors, the whole body disease in the worldwide.(omitted)

• Journal of Korean Dental Science
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• v.15 no.2
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• pp.147-151
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• 2022

Horizontal root fracture (HRF) is a result of trauma to teeth and periodontium, which implies severe injury to cementum, dentin, and pulp. This is a rare case of HRF in the maxillary lateral incisor of a 62-year-old male who only presented persistent gingival swelling, fistula, and dull pain at first. An apical radiolucency of unknown origin turned out to be a result of hidden HRF at the coronal third level that was later visualized radiographically during endodontic treatment. The tooth was scheduled to be extracted upon the patient's agreement. The purpose of this report is to alert clinicians about the importance of diagnosing HRF through thorough clinical and radiographic examinations. Where there is persistent fistula without proper cause, HRF should be considered as a causative factor, and the diagnosis could be effective with aid of cone beam computed tomography, electronic root apex locator, as well as other clinical signs.

• Journal of Periodontal and Implant Science
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• v.23 no.3
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• pp.577-594
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• 1993

The ultimate goal of periodontal therapy is the regeneration of the periodontium that have been destroyed as a result of periodontal disease. This study were done in order to determine the healing status of periodontium under Polytetrafluoroethylene and millipore fillter combined with fibrin and the effect of the guided tissue regeneration procedures were performed as follows : 1) flap operation using PTFE membrane(control group) 2) flap operation using PTFE membrane which was fixed with fibrin(experimental group 1) 3) flap operation using millipore filter which was fixed with suture(experimental group II) 4) flap operation using millipore filter which was fixed with fibrin(experimental group II) After 1, 2, 4, 8, 12 weeks, dogs were sacrificed by perfusion technique and tissue block was excised including the tooth and prepared for light microscope with H-E & Masson’s trichrome staining. The result were as follows : In control and experimental group, there is no siginificant difference on epithelial cell down growth within 1st week, but more epithelial cell downgrowth in millipore or millipore combined with fibrin group. In this experiment, there were no significant difference in new cementum and alveolar bone formation whether PTFE membrane was fixed with suture or fibrin. In control and each experimental group, bone maturation appeared in 4 weeks, bone width increased bucco-lingually in control and experimental 1 group especially. Both control group and experimental group showed mild mew cementum formation on root surface and irregular arrangement of collagen fiber at 4 weeks, that showed obvious increased cementum formation at 8 weeks, and that was observed the functional arrangement of collagen fiber between new cementum and new alveolar bone at 12 weeks.

• Journal of dental hygiene science
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• v.12 no.1
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• pp.71-77
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• 2012

Sex Hormones exert significant influence in body physiology throughout life. Some reports suggested increased sex hormone levels correlate with an increased prevalence of gingivitis. The objectives of this pilot study are to(1) address the link between menstrual cycle and MMP-9, MMP-8, IL-$1{\beta}$ of gingival crevicular fluid during 4 weeks and (2) discuss the major biomarker of periodontal status. 7 female and 3 male volunteer who didn't have smoking habit, medical and dental disease after informed consent, were seen twice a week for 4 weeks. GCF samples were collected and GCF levels of MMP-9, MMP-8, IL-$1{\beta}$ were measured by enzyme-linked immunosorbent assay. The GCF levels of MMP-9, MMP-8, IL-$1{\beta}$ had fluctuation according to menstrual cycle, but the changes of those were not significant by Friedman matched samples test. There is no difference between female and male subjects by Mann-Whitney U test. The correlation of MMP-8, MMP-9 and IL-$1{\beta}$ showed strong by Spearman correlation(0.644-0.945). This study confirms menstrual cycle doesn't influence the periodontium of healthy female subjects.

• Journal of Periodontal and Implant Science
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• v.32 no.3
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• pp.643-653
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• 2002

Periodontal supporting tissue goes through destruction by chronic inflammatory periodontal disease as two aspect. One is qualitive aspect such as alteration of periodontium, the other is quantitative aspect such as alveolar bone loss. According to many authors, PDL is responsible for biting force, and there are two mean. for measuring PDL's function - mobility test and biting force test. This study was conducted to compare the biting force with remaining bone level, that is, quantitative aspect of periodontium, in anterior and premolar teeth at periodontal maintenance phase. 17 patients on periodontal maintenance phase during 6 months at minimum were selected for this study. For the same condition, 4 anterior, canine, premolar teeth were tested by MPM-3000 bite-force register at the same time(a.m.l0-12), the same position, the same posture, by the same examiner. Patients of TMI), ill-fitting pros thesis, general disease, malocclusion and the teeth of TFO, absence of opposing teeth, malposition were excluded. Remaining bone level was measured on the panorama X-ray film through 5 level from 1mm below CEJ to root apex. Teeth were examined twice, and bigger one was selected. If the values showed large difference. examinatin was re-done and the mean was selected. The results were as follows ; 1. In the 4 anterior group, as the remaining bone is decreased, the average of maximal biting force is decreased. Especially, at 3/5 bone level, maximal biting force is decreased significantly(p<0.01). 2. In the canine group, as the remaining bone is decreased, the average of maximal biting force is decreased. Especially, at 2/5 bone level, maximal biting force is decreased significantly(p<0.01). 3. In the premolar group, as the remaining bone is decreased, the average of maximal biting force is decreased. Especially, at 3/5 bone level, maximal biting force is decreased significantly(p<0.05). From the results of this study, clinicians could utilize these efficiently when they have to determine the proper restorative materials, time for tooth extraction, treatment plan, prognosis.

• Journal of Periodontal and Implant Science
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• v.32 no.3
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• pp.501-521
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• 2002

The purpose of this study is to evaluate the influences of the bone morphogenetic protein (BMP) on the healing of periodontal ligament and alveolar bone after replantation of tooth, and to examine the possibility of its clinical application. 45 Sprague Dawley rats weighted about 100 gram were divided into 3 experimental groups by different dose of BMP. All the upper right and left 1st molar were extracted after 5 days feeding of 0.4% ${\beta}$-aminopropionitrile, and right molar were used as experimental group and left molar were used as control group. The root surface of experimental molar were treated with 25,50 and l00ng/ml of human recombinant Bone morphogenetic protein-4 (rh-BMP-4) with micropipet, and 1M Sodium hypochloride were used on control root surface. All the experimental animals were sacrificed as 1, 2, 4, 7 and 14 days after autoreplantation of upper 1st molar into their own position. The maxilla were disected included both side of 1st molar. The collected tissue were processed from demineralization to paraffin embeding as usual procedure, and the specimens were prepared with Hematoxylin-Eosin stain for the light microscopic evaluation. The results of this study were as follows : 1. There was no significant differences between control and experimental site on 1 and 2 days after replantation of tooth. In the case of 4th days, the evidence of tissue regeneration were observed on experimental site to compare the controls. New osteoid were revealed on high concentration of BMP at 7 days after replantation, and it became more obvious at 14 days, 2. The effect of the rh-BMP-4 coated on root surface was revealed slight influences for the prolifertion of cells of periodontium and tissue regeneration as dose-dependent pattern. 3. Bony ankylosis was observed between alveolar bone and root surface due to the remarkable amount of osteoid formation on the 14 days after replantation of root. In the conclusion, it was suggested that topical application of the rhBMP-4 on the root surface has influence on the periodontal ligament and alveolar bone. The application method of BMP on the root should be designed with calculation of proper concentration.

• Journal of Periodontal and Implant Science
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• v.36 no.3
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• pp.783-796
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• 2006

The periodontium is a topographically complex organ consisting of epithelial tissue, soft and mineralized tissues. Structures comprising the periodontium include the gingiva, periodontal ligament (PDL) , cementum and the alveolar bone. The molecular mechanism of differentiation in PDL fibroblast cells remain unclear. Amino acid transporters play an important role in supplying nutrition to normal and cancer cells and for cell proliferation. Amino acid transport system L is a major nutrient transport system responsible for the Na+-independent transport of neutral amino acids including several essential amino acids. The system L is divided into two major subgroups, the L-type amino acid transporter 1 (LAT1) and the L-type amino acid transporter 2 (LAT2). In this study, the expression pattern of amino acid transport system L was, therefore, investigated in the differentiation of PDL fibroblast cells. To determine the expression level of amino acid transport system L participating in intracellular transport of amino acids in the differentiation of PDL fibroblast cells, it was examined by RT-PCR, observation of cell morphology, Alizaline red-S staining and uptake analysis after inducing experimental differentiation in PDL fibroblast cells isolated from mouse molar teeth. The results are as follows. 1. The LAT1 mRNA was expressed in the early stage of PDL fibroblast cell differentiation. This expression level was gradually reduced by differentiation- inducing time and it was not observed after the late stage. 2. The expression level of LAT2 mRNA was increased in time-dependent manner during differentiation induction of PDL fibroblast cells. 3. There was no changes in. the expression level of 4F2hc mRNA, the cofactor of LAT1 and LAT2, during differentiation of PDL fibroblast cells. 4. The expression level of ALP mRNA was gradually increased and the expression level of Col I mRNA was decreased during differentiation of PDL fibroblast cells. 5. The L-leucine transport was reduced by time from the early stage to the late stage in PDL fibroblast cell differentiation. As the results, it is considered that among neutral ammo acid transport system L in differentiation of PDL fibroblast cells, the LATl has a key role in cell proliferation in the early stage of cell differentiation and the LAT2 has an important role in the late stage of cell differentiation for providing cells with neutral amino acids including several essential amino acids.

• 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 Dental Rehabilitation and Applied Science
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• v.28 no.1
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• pp.15-25
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• 2012

The relationship between occlusion and periodontal health has been extensively studied. However, reports on the effects of passive eruption using occlusal reduction has not been sufficient. The purpose of the present randomized clinical trial was to assess the influence of passive eruption using occlusal reduction on the clinical periodontal parameters consisting of attachment level, pocket depth, tooth mobility, width of keratinized gingiva and osseous defect. The study was performed on 40 teeth of 16 subjects who have been treated for the moderate periodontitis at the Department of Periodontology, Pusan National University Hospital. At the baseline examination, after hygienic-phase and after 6 month from passive eruption using occlusal reduction, clinical parameters were monitored and radiographs were taken. The 20 teeth in the test group received passive eruption using occlusal reduction while the 20 control teeth did not receive any occlusal reduction. The results were as follows; 1) Degree of inflammation of periodontium was improved by initial therapy 2) Teeth received passive eruption using occlusal reduction demonstrated significantly greater reduction in pocket depth, tooth mobility and amount of bone loss, and increase in the width of keratinized gingiva, but no significant changes in the attachment level compared to the control teeth 3) There was significantly greater reduction in pocket depth, mobility, amount of bone loss and attachment level in the test teeth after initial hygienic phase when compared with baseline data. Taken together, these results suggest that the passive eruption using occlusal reduction would be helpful to improve periodontal health.