• Journal of Periodontal and Implant Science
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• v.24 no.1
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• pp.51-63
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• 1994

There has been many attempts to develop a method that can regenerate periodontal tissues that were lost due to periodontal diseasd, but none of them was completely successful. This study was designed to investigate the healing and regeneration of periodontal tissue when bone substitutes such as porous replamineform hydroxyapatite and porous resorbable calcium carbonate were used in combination with oxidized cellulose membrane and collagen absorbable hemostat, compared to a control where only oxidized cellulose membrane or collagen absorbable hemostat were used. Chronic periodontitis was induced on mandibular premolars of and adult dog by placing orthodontic elastic ligatures for 10 weeks. After flap operation, the control group were received oxidized cellulose membrane (control- I )or collagen absorbable hemostat (control- II) only, while one experimental group was given either porous replamineform hydroxyapatite or porous resorbable calcium carbonate in addition to oxidized cellulose membrane (Experimental I-A, I-B), and another experimental group was treated by using either porous replamineform hydroxyapatite or porous resorbable calcium carbonate in addition to collagen absorbable hemostat. (Experimental II-A, II-B) After 56 weeks, healing was histologically analyzed with the following results. 1. Apical migration of junctional epithelium was observed only in areas coronal to the notch for both control and experimental group. 2. Inflammatory cell infiltration was not observed in any groups. 3. Oxidized cellulose membrane and collagen absorbable hemostat were completely resorbed. 4. Newly-formed cementum was observed up to the level where junctional epithelium was located, for both control and experimental groups. 5. Bone formation was limited of the middle portion of the notch in the control group, where as experimental groups showed bone formation up to the level of implant materials coronal to the notch. 6. Minute resorption of apically located portions of implanted materials was observed in experimental group I-B and II-B only.

• Journal of Periodontal and Implant Science
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• v.24 no.1
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• pp.205-216
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• 1994

The goal of periodontal therapy is the regeneration of the periodontium lost by periodontal disease. The purpose of this study was to evaluate the regenerative potential of the autogenous bone graft and guided tissue regeneration in the treatment of periodontal bony defect in dogs. Experimental periodontitis were induced in the mandibular left 3rd premolar and right 3rd and 4th premolars of 5 dogs using orthodontic ligature wire. After 6 weeks, the ligature wire removed, surgical procedure were performed as follows. 1) control group : Flap operation(Mn.Lt 3rd premolar) 2) experimental group I : Flap operation + autogenous bone graft (Mn.Rt. 3rd premolar) 3) experimental group II : Flap operation + Gore-Tex membrane (Mn.Rt. 4th premoalr) Thereafter, dogs were sacrificed on the 1,2,4,8,16th week and the specimens were prepared and stained with hematoxyline-eosin stain for the light microscopic examination. The results of this study were as follows. 1. The apical migration of junctional epithelium was most remarkable in the flap operation and the experimental group II was less than the experimental group I. 2. In the formation of new alveolar bone, it was found in experimental group I,II and experimental group I is more than II. In the control group, few bone formation was found. 3. In the formation of new cementum, it was found in experimental group I,II and experimental group II is more than I. So, the periodontal therapy combined with autogenous and guided tissue regeneration will be produce the periodontal regeneration.

• Journal of Periodontal and Implant Science
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• v.27 no.1
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• pp.191-203
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• 1997

Recently, alteration on chemical treatment on the root and removal of pathologic bacteria, which is the main reason for periodontal disease, by complete removal of infected cementum layer was been emphasied In this study, teeth extracted due to periodontal disease were root planed using periodontal curette and roto bur. Then they were treated with different concentration of Tetracycline HCI at different time. The state of root surface and change in the pre and post treatment was observed. The results were as follows. 1. The group treatment with periodontal curette and saline showed remaining plaque, debris and irregular surface and no dentianl tubule orifice could be seen. 2. The group treatment with periodontal curette and tetracycline HCI showed process compoed with decacified material and there was concanity seemed to be a lacunae of cementocyte. 3. The group treatment with roto bur and saline, there was no remaning plaque and partial dentinal tubule orifice could be seen but smear layer covering them.4. The group treatment with roto bur and tetracycline HCI showed various shape and size dentinal tubule orifice could be seen. From the results, roto bur showed cleaner surfaces than treatment with periodontal curette. But still smear layer existed. Thus for regeneration of periodontal tissue, chemical treatment using tetracycline HCI should follow roto bur treatment. And it is considered that the treatment time is more important than the concentration of tetracycline HCl.

• Journal of Periodontal and Implant Science
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• v.24 no.1
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• pp.87-97
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• 1994

The ultimate goal of periodontal therapy is to fully reconstruct the periodontal attachment apparatus. Commonly used techniques for treatment of infrabony defects include a combination of root planing, curettage and root treatment. To prevent the apical migration of epithelial cells, the technique of guided tissue regeneration is used. The aim of this study is to compare the effects of root treatment with Citric acid & Tetracycline and Guided tissue regeneration in dogs. Experimental periodontitis was induced by the ligation of orthodontic elastic threads in the upper right and left premolars 3, 4 of five adult dogs for 6 weeks. 4 types of procedures were performed as follows; 1) Control graup : Mucoperiosteal flap 2) Experinental I : GTR used Gore-tex(R) membrane 3) Experinental II : Root treatment with citric acid (PHl) 4) Experinental III : Root treatment with tetracycline HCl (50mg/ml) There after, dogs were serially sacrificed at the 1, 2, 4, 5, 8 weeks, and the specimens were prepared, and stained with hematoxylin-eosin for the light microscopic evaluation. The results of this study were as follows; 1. Junctional epithelium reached to the notch through the furcation area in control group at 8 weeks. 2. In the aspects of the inflammatory cell infiltration, control group showed severe aggregation than experimental group I, II, III through the experimental period 3. New cementum was observed over the notch from 5 weeks in experimental group II 4. In the aspects of the amount of new bone formation, experimental group was better than control group, but there was not significant differences among the experimental group, I, II, III

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.5
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• pp.579-588
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• 2007

Statement of problem: A tenderness of the dentin after tapering of teeth for dental prosthesis is a common phenomenon. In practice, the alternative desensitizer may be used for minor pain after tapering of teeth. Purpose: In this study, the desensitizers were used to investigate the affect decreasing of shear bond strength according to the use of various cement, such as resin, Glass Ionomer, and phosphate cement. Material and method: Three different desensitizers were used on this study Compositions of two dentin desensitizers were HEMA(hydroxyethylmethacrylate) and glutaraldehyde. The other one is oxalic acid. Three dentin desensitizers applied on 12 degrees taper teeth. Then, Ni-Cr crowns were bonded with Resin cement, Zinc Phosphate (ZPC) cement and Glass Ionomer (GIC) cement. 120 human premolar teeth were used for specimens. The specimens were divided into four group as the reference and the empirical each with thirty specimens, then further divided into 12 group according to type of desensitizers and cement types. The shear bond strength were measured by Instron multi task instrument. Results: According to the result, the measured shear bond strength in order from the weakest to the strongest in general was ZPC, Resin, and GIC. And it is found that the application of desensitizers on dentin surface does not affect the shear bond strength. Conclusion: Dentin desensitizers that alleviate or prevent a dentin tenderness, usually contains HEMA and glutaraldehyde compounds. Such desensitizers are widely used in clinical studies. By applying the dentin desensitizer on the exposed dentin surface, the dentin capillary are blocked and periodontal membrane and cementum can not be drawn in pulp cavity. Since HEMA and glutaraldehyde may cause harm to the pulp cavity, an alternative desensitizer was developed.

• Journal of Periodontal and Implant Science
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• v.40 no.4
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• pp.172-179
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• 2010

Purpose: Accurate and exact measurement is an important factor for generating meaningful results in any properly designed study. If all the participating examiners are able to yield similar results, it will be possible to evaluate the objective results of the study more easily and quickly. The purpose of this study was to evaluate the intra- and inter-examiner reproducibility of histometric measurements in the intrabony periodontal defect model. Methods: One wall intrabony defects were surgically created at the distal aspect of the second and the medial aspect of the fourth mandibular premolars in the right and left jaw quadrants in twenty beagle dogs and the defect sites received the following ${\beta}$-tri calcium phosphate, growth differentiation factor-0, growth differentiation factor-100 and sham surgery. Histometric analysis was performed after 8 weeks. Histometric parameters were recorded and repeated at three months interval by three examiners. Intra- and inter-examiner reproducibility was assessed. Results: Most parameters of all the groups showed high intra- and inter-examiner reproducibility. Parameters including defect height, bone regeneration height, cementum regeneration height, and formation of junctional epithelium yielded interexaminer correlation ${\geq}0.9$. The intra-examiner reproducibility showed a high result, over 0.9. Conclusions: Histometric evaluation of the one-wall intra-alveolar periodontal defect model showed high reproducibility not only for a single given examiner but also among the three examiners.

• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.1
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• pp.73-78
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• 2012

Complex odontomas consist of a conglomerate mass of enamel, dentin and cementum which bears no anatomic resemblance to a tooth. The majority of these lesions are completely asymptomatic, being discovered on routine radiographic examination or when films are taken to determine the reason for tooth eruption failure. Compound odontomas seldom cause bony expansion, but complex odontomas often cause slight or even marked bony expansion. Complex odontomas are mostly associated with permanent teeth and very rarely associated with deciduous teeth. They are usually located in the first-or second-molar areas of the mandible. This report presents a case of a patient with impaction of a maxillary primary canine by a complex odontoma in which surgical excision of the lesion was performed. And the primary canine was repositioned right under gingival level for spontaneous erution. Follow-up after six months showed spontaneous eruption ofthe repositioned maxillary primarycanine.

• Journal of Periodontal and Implant Science
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• v.30 no.4
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• pp.793-803
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• 2000

Procedures for treatment of molar furcation invasion defects range from open flap debridement, apically repositioned flap surgery, hemisection, tunneling or extraction, to regenerative therapies using bone grafting or guided tissue regenerative therapy, or a combination of both. Several clinical evaluations using regenerative techniques have reported the potential for osseous repair of treated furcation invasions. Regenerative treatment of maxillary molars are more difficult due to the multiple root anatomy and multiple furcation entrances therefore, purpose of this study was to evaluated histologically self-curing glass-ionomer cement and light-curing glass-ionomer cement as a barrier in the treatment of a bi-furcated maxillary premolar. Five adult beagle dogs were used in this experiment. With intrasulcular and crestal incision, mucoperiosteal flap was elevated. Following decortication with 1/2 high speed round bur, degree II furcation defect was made on maxillary third(P3), forth(P4) and fifth(P5) premolar. 2 month later experimental group were self-curing glassionomer cement and light-curing glassionomer cement. After 4, 8 weeks, the animals were sacrificed by vascular perfusion. Tissue block was excised including the tooth and prepared for light microscope with Gomori's trichrome staining. Results were as follows. 1. In all experiment group, there were not epithelial down growth and glass ionomer cement were encapsulated connective tissue. 2. In 4 weeks experiment I group slighly infiltrated inflammatory cells but not disturb the new bone or new cementum formation. 3. In 8 weeks, experiment groups I, II were encapsulated fine connective tissue. 4. Therefore glass-ionomer cement filling to the grade III maxillary furcations with multiple root anatomy and multiple furcation entrances were possible clinical methods and this technique is useful method for Maxillary furcation involvement.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.3
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• pp.555-561
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• 1998

Hypophosphatasia is a rare metabolic disorder which manifests characteristics such as abnormal mineralization of bone and dental tissues, diminished serum and tissue alkaline phosphatase, and increased urinary secretion of PEA. It inherited as an autosomal recessive or dominant trait and occurs in all races. In general, hypophosphatasia can be classified in 4 subtypes which are the perinatal, infantile, childhood, adult type depending upon the age at presentation and severity. In young children with Hypophosphatasia the long bones show irregular defects, and the skull showes poor calcification. In older children with premature closure of the skull sutures there may be multiple lucent area called gyral or convolutional markings, described as resembling beaten copper, presumably resulting from increased intracranial pressure. Examination of the jaws reveals a generalized lucency of the maxilla and mandible. the cortical bone and lamina dura are thin, and the alveolar bone may be deficient. Clinical features of Hypophosphatasia include premature loss of deciduous teeth, especially incisors, hypoplasia or aplasia of root cementum, enamel hypoplasia, irregular calcification of dentin, large pulp chamber, and resorption of marginal alveolar bone and roots. Our report involves a patient with a chief complaint of early loss of both Mx. and Mn. deciduous incisors. After conducting a through clinical and radiographic examination this patient was referred to pediatrics under the suspicion of hypophosphatasia, the diagnosis proved to be correct and successful results were accomplished through a denture made to improve esthetics and function.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.28 no.1
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• pp.171-191
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• 1998

The present study was designed to elucidate the effects of the Co-60 γ irradiation and/or calcium-deficient diet on the periodontal tissue formation in rat pups. The pregnant three-week old Sprague-Dawley rats were used for the study. The experimental group was divided into two groups, irradiation/normal diet group (Group 2) and irradiation/calcium-deficient diet group (Group 3). The control group was non-irradiation/normal diet group (Group 1). The abdomen of the rats at the 19th day of pregnancy were irradiated with single absorbed dose of 350 cGy. The rat pups were sacrificed on the 14th day after delivery, and the maxillae including molar tooth germ were taken. The specimens including the 1st molar tooth germ were prepared to make tissue sections for light and transmission electron microscopy. Some of tissue sections for light microscopy were stained immunohistochemically with anti-fibronectin and anti-osteonectin antibodies. The results were as follows; 1. In the periodontal ligament forming area, the fibroblasts of Group Z showed irregular arrangement and low activity. The immunoreactivity between the fibroblasts and collagen fibers was decreased, compared with Group 1. The fibroblasts of Group 3 showed atrophic change and clumped nucleus. The collagen fibers showed cystic change and low immunoreactivity to the fibronectin. 2. In the cementum forming area, the cementoblasts of Group 2 showed decrease of number and atrophic change. The cementoblasts of Group 3 showed edematous change, atrophy of cytoplasm, and clumping of nucleus. 3. In the alveolar bone forming area, the bone of Group 2 was thin and various degree of immunoreactivity to the osteonectin. Group 3 showed edematous osteoblasts, fibrous degeneration of bone marrow, and weak immunoreactivity to the osteonectin.