• Maxillofacial Plastic and Reconstructive Surgery
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• v.15 no.2
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• pp.137-145
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• 1993

The purpose of this study was to observe the effect on teeth and tibia bone histopathologically in rats by the richitogenic diet. For this purpose, 48 sprague-dewley rats, weighing 80g or more, divided into 6 groups, and sacrificed on the 1st, 2nd, 3rd, 4th, 5th, 6th weeks after experiments respectively. The tissues contain tooth, and tibial bone were fixed in 10% normal formalin solution, decalcified in Plank-Rychlo solution, embedded in paraffin, sectioned in $6-8{\mu}$ as usual manner, the tissues were stained in hematoxylin eosin, and examined hisopathologically. Follow results were attained 1. Pyknotic appearance of odontoblastic layer was noticed on the 1st week, and increased on the 2nd weeks, and it is appeared that degeneration and dearrangements of odontoblasts on the 4 weeks. But a little recovered on the 6th weeks. 2. The thickness of predentin layer was increased on the 2nd weeks, and increased remarkedly on the 3rd weeks and reached the maximum on the 5th weeks. 3. The interglobular dentin was appeared in spotty shape on the 2nd weeks, and increased on the 4th, 5th, weeks, and large amount of inter-globular dentin was appearanced on the 6th weeks. 4. It is appeared that enamel hypoplasia on the 4th weeks. 5. Epiphyseal and metaphyseal plate of tibia was increased from/on the 2nd weeks, increased maximumly on the 5th weeks. And pyknotic, dearrangements, and hyperchromatic appearances of chondrocytes on the plate were increased on the 1st week.

• Journal of the korean academy of Pediatric Dentistry
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• v.8 no.1
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• pp.37-46
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• 1981

This study was undertaken to evaluate the pulpal responses to the pulp-capping materials such as glutaraldehyde and formocresol in pulpotomy technique, especially in the primary dentition. Mandibular primary canines and molars of 5 dogs (aged about 8-9 weeks)were selected for this study. The intervals of observation for histologic study of pulpotomized primary teeth with 2% glutaraldehyde, formocresol and calcium hydroxide in the usual manner ranged from 2 hours, 1 week, 2 weeks, 3 weeks and 5 weeks after experiments respectively. Each specimens were fixed with 10% formalin and decalcified in 5% nitric acid. All slides were stained with Hematorylin-Eosin and examined histopathologically. The results were as follows; 1. In calcium hydroxide groups, formation of dentin bridge was initiated in 1 week after experiments and completed in 5 weeks after experiments. 2. Formation of dentin bridge was not seen, whereas necrosis of pulp tissue was noted, in formocresol and glutaraldehyde groups. 3. Duration of tissue reactions and tissue changes were similar, in formocresol and glutaraldehyde groups. 4. In formocresol and glutaraldehyde groups, amputation surfaces of the pulp were covered with blood clots, beneath which coagulation necrois was noted, but inflammatory cells were not prominent, in 2 hours and 1 week after experiments. But coagulation necrosis was proceeded to the apical portion, accompanied by infiltration of inflammatory cells, since 2 weeks after experiments. And suppuration or gangrene of the pulp tissue were noted in 3 weeks and 5 weeks groups. 5. Suppuration or gangrene of pulp seemed to provoke the resorption of dentin wall, and inflammatory changes and resorption of roots were noted in the periodontal membrane near the periapical region. 6. As compared with calcium hydroxide groups, resorption of the root was pronounced in form or cresol and glutaraldehyde groups. Effects of medicaments to the succedaneous tooth germ were not seen.

• Restorative Dentistry and Endodontics
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• v.13 no.1
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• pp.7-19
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• 1988

The object of this paper was to investigate the histopatological changes on dog's pulp under cavitation by irradiation of the $CO_2$ laser. The subjects were derived from four dogs, and irradiated 113.23 J/$mm^2$, 283.09 J/$mm^2$, 566.08 J/$mm^2$ in Group I, II, and III respectively. The dogs were sacrificed immediately, 24 hour, 72 hour and 1 week after $CO_2$ laser treatment. For light microscopic examination, routine H-E and PAS stains were employed. For electron microscopic observation, the teeth were fixed in 1% paraformaldehyde and 1% glutaraldehyde, decalcified teeth in 10% EDTA were stained by uranyl acetate and lead citrate. The observation was made with a Hitachi H-500 model electron microscope. The following results were obtained in this study: 1. At the early stage of the experimental sub-groups-immediately, 24 hour, 72 hour samples of Group I, II and III-coagulation necrosis and hyperemia were observed in odontoblastic and subodontoblastic pulpal layer. 2. At the 1 week sub-group of Group I, II, regenerative hyperplasia of the odontoblasts without coagulation necrosis were revealed, in addition to thickened predentin. On he other hand coagulation necrosis and atrophic change accompanying with hyperplasia were found at the 1 week sub-group of Group III. 3. Ultrastructurally, the odontoblasts appeared nuclear degeneration, vacuolar change of cytoplasmic organelles and rupture of plasma membrane at the early stage of the experimental period of all groups. 4. Under spectrohelioscopic examination, regenerative odontobalsts were seen at the 1 week specimens of Group I, II and III. 5. The pulpal response occured at 113-566 J/$mm^2$. The pathologic change of pulp tissue occured at the early experimental period but regeneration of odontoblasts could be seen after 1 week.

• Restorative Dentistry and Endodontics
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• v.13 no.1
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• pp.103-111
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• 1988

The purpose of this study was to, examine the sealing ability of the denting bonding agent, when used with gutta percha cone, as a root canal sealer. Seventy two upper and lower extracted human teeth with single root were randomly selected and instrumented in a conventional method with K-file. After instrumentation and dry the canal with paper point, there were divided into three groups and twenty four teeth in each group were filled with the following material; In group I: Scotchbond in combination with gutta percha cone. In group II: AH 26 in combination with gutta percha cone. In group III: Tubli-Seal in combination with gutta percha cone. All specimens were immersed in Indian Ink, decalcified, and cleared. The depth of dye penetration into the canals were evaluated by caliper at the intervals of 1 day, 1 week, 2 weeks. The results were as follows; 1. Depth of dye penetration for all groups increased with time. 2. As to difference in mean dye penetration at time interval of 1 day and 14 days, Scotchbond group exhibited the smallest value as 0.53mm and Tubli-Seal group exhibited the largest value as 0.70mm. 3. There was the difference of dye penetration between each group, but its difference was not significant, statistically.

• Journal of Periodontal and Implant Science
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• v.31 no.1
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• pp.193-209
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• 2001

The prognosis of transplanted teeth is strongly related with periodontal healing. Several experimental studies showed that the application of enamel matrix derivatives on periodontitis-affected root surfaces resulted in periodontal regeneration. The purpose of this study was to determine the effect of enamel matrix derivatives on periodontitis-affected root surfaces prior to transplantation in dogs. Class III Furcation defects were surgically created on the left second, the third and the fourth premolar in the mandibles of nine mongrel dogs and experimental periodontitis was induced by placing small cotton pellets into defects for 3 weeks. Periodontitis-affected roots were treated by scaling and planing and the coronal portions were removed. Each root was extracted and implanted into recipient bed prepared in the contralateral premolar area. The transplanted roots were grouped according to the treatment modalities; Group I- roots treated with saline only, Group II- roots conditioned by neutral EDTA, and Group III- roots conditioned by neutral EDTA and enamel matrix derivatives ($EMDOGAIN^{(R)}$, BIORA Co., Sweden). The animals were sacrificed at 1 week, 3 weeks, and 10 weeks after transplantation and decalcified specimens were prepared for histologic examination. In Group I, healing was most frequently characterized by root resorption and ankylosis. In Group II, with root resorption and ankylosis in a few specimens, connective tissue attachment was partly seen on denuded root surface, but no cementum formation was seen. In Group III, there was regeneration by new cementum and periodontal ligament on denuded root surface, although slight root resorption and ankylosis were found in a few specimens. This result suggests that enamel matrix derivatives treatment on periodontitis-aggected root surface could reduce the frequency of root resorption and ankylosis and contribute to periodontal regeneration, and might be useful for autologous transplantation.

• Restorative Dentistry and Endodontics
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• v.14 no.1
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• pp.71-84
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• 1989

The purpose of this study was to evaluate the effect of tricalcium phosphate and Vitapex on the dogs' periapical tissues. Twenty mandibular premolars from 5 healthy dogs were used for this study. After the animals were anesthetized intramuscularly, pulp chambers were open and pulp tissue was extirpated with a barbed broach and H-file. Then the working length of the root canal was measured with H-file and pulp tissue was completely removed. Before the actual canal filling, the root canals of twenty teeth have been experimentally infected with opening the pulp chamber for 5 weeks. Periapical radiographs of the experimental teeth were taken to monitor the periapical pathological condition. Each root apex of 20 premolars was perforated with engine reamer and the root canals were enlarged with No. 30-60 H-files. They were divided into treated as follows. Control group: The root canal was filled with gutta-percha. Experimental group 1: The canal was dried with sterile paper points and mixture of tricalcium phosphate and physiological saline was overfilled beyond the root apex with a lentulo spiral. Then the root canal was filled gutta-percha and lateral condensation and the pulp chamber was filled with Caviton. Experimental group 2: The root canals were overfilled with Vitapex and were treated in the same manner as those in experimental group 1 At 1,2,3, and 8 weeks after experiment, the periapical tissues including the alveolar bone were fixed with 10% formalin solution for I week and decalcified with Plank-Rycho solution for 5 weeks. The specimens were embedded in paraffin and serial sections were cut into a thickness of 6 ${\mu}m$ at the plane of the root apex. Hematoxyline-eosin and Masson's trichrome stain were made for the histo-pathological examinations. The results were as follows: 1. Ingrowth of collagen fiber was observed from 1 week in control group and experimental groups. 2. The rate of bone formation of experimental group 1 was accelerated more than that of experimental group 2. 3. Resorption of cementum was seen in control group, but apposition of cementum was seen in experimental groups.

• Journal of the korean academy of Pediatric Dentistry
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• v.10 no.1
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• pp.35-45
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• 1983

This study was undertaken to evaluate the pulpal responses to the intermediate restorative materials such as Zinc phosphate cement, Polycarboxylate cement, IRM (zinc oxide eugenol cement), Dycal, Life, Cresatin, and Fluoride in caivties which were cut with high speed instrument. 5 dogs were used as experimental animals and devided into 8 groups. The intervals of observaobservation ranged 3 days, 1, 3, 4, 8 weeks after experiment respectively. The specimens were fixed with 10% formalin and decalcified in 5% nitric acid. All slides were stained with hemtoxylin-eosin and examined histopathologically. The results were as follows: 1. In control group, severe vacuolar degeneration and atrophy of odontoblasts were seen in 3 days, hemorrhage and congestion continued until 8 weeks. Necrosis of odontoblastic layer was seen in zinc phosphate cement group and polycarboxylate cement group. 2. In dycal group, vacuolar degeneration and atrophy of odontoblast were not seen. but in Life group, these were seen in 3 days and partially continued until 3 weeks. In 4 weeks, regeneration of odontoblast was occured. 3. In Crcsatin group, there was no pathosis except odontoblastic displacement. In Fluoride group, vacuolar degeneration of odontoblast was seen and soon disappeared. As compared with control group, pathological change of the pulp tissue in experimental group were decreased after amalgam restoration.

• Restorative Dentistry and Endodontics
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• v.15 no.2
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• pp.34-45
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• 1990

The purpose of this study was to evaluate the pulpal responses of S. mutans (6715, serotype A) in relation to the remaining dentin thickness. The material was consisted of 72 teeth from 6 dogs. Cl. V cavities were prepared into 2 different thickness (0.5mm, 1.0mm) of remaining dentin. In the control groups, the cavities were filled with filter paper of broth, tin foil, and IRM$^{(R)}$ cement. In the experimental groups, the cavities were filled with filter paper of S. mutans, filter paper of broth, tin foil, and IRM$^{(R)}$ cement. The intervals of observation period were 1 week, 3 weeks, and 8 weeks respectively after the experiment. The specimens were fixed with 10% formalin and decalcified in 5% nitric acid. All specimens were stained with Hematoxylin-Eosin and examined histopathologically under the microscope. The results were as follows. 1. The changes and congestion of odontoblastic layers were more frequent and lasting in the control group of 0.5mm than in that of 1.0mm remaining dentin thickness. 2. There was no characteristic difference between the control group of 1.0mm and the experimental group of 1.0mm in all pulp responses. 3. Acute and chronic inflammatory cells were seen in the experimental group of 0.5mm, but not seen in the control group of 0.5mm.

• Restorative Dentistry and Endodontics
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• v.14 no.2
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• pp.31-37
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• 1989

The purpose of these study was to compare the sealing ability of a injection-molded thermoplasticized gutta-percha and silver amalgam as retroseal material in vitro. Sixty two upper and lower extracted human teeth with single root were randomly selected and instrumented in a conventional method with H-file. After instrumentation the root canal was obturated with gutta-percha by lateral condensation technique with AH26 and an apicoectomy was performed by beveling the root tip 45 angle. In the experimental group 1 and 2, a class I preparation was made and filled with silver amalgam or gutta-percha and in the experimental group 3 an apicoectomy only was performed. All specimens were immersed in black Indian ink, decalcified and cleared. The depth of dye penetration into the canals were evaluated by califer. The results were as follows ; 1. The experimental group 1 displayed the smallest mean dye penetration as 0.45mm. 2. The experimental group 3 displayed the greatest mean dye penetration as 0.65mm. 3. There was the difference in dye penetration between each group, but the difference was not statistically significant(P>0.05).

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.1
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• pp.1-12
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• 2006

The purpose of this study were to evaluate the efficacy of the newly developed Digital Imaging Fiber-Optic Trans-illumination (DIFOTI) system in detecting carious lesions in vivo as gold standard with confocal laser scanning microscopy and compared the efficacy of traditional radiography and DIFOTI system in vito as gold standard with confocal laser scanning microscopy, too. For the in vivo study, the subject pool consisted of 23 grammar school age patients just prior to entering the mixed dentition phase Each patient was given a DIFOTI examination of the anterior and posterior teeth. During $6{\sim}8$ months, the naturally expire primary teeth were collected and the efficacy of DIFOTI system was compared with confocal laser scanning microscopy. For in vitro study, 40 primary teeth were collected and decalcified by Carbopol decalcification solution for 1, 2, 4 and 8 days. Every experiment period, all teeth were DIFOTI examined and sectioned to take an image of confocal laser scanning microscopy Sensitivity and specificity were calculated from the result of DIFOTI examine and confocal laser scanning microscopy analysis. The results are as follows : 1. From the in vivo study, the sensitivity of DIFOTI examine was 0. 61 and specificity was 0.63. 2. From the in vivo study, the sensitivity of DIFOTI examine was 0.71 and specificity was 0.75.