• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.4
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• pp.524-534
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• 2000

Deciduous teeth can be extracted for two reasons, one due to the physiologic resorption and the other by the inflammation at the apex after traumatic injury. Physiologic resorption may be different from pathologic resorption in timing and mechanism. Therefore we resumed the different features of physiologic and pathologic resorption root surfaces. Many previous studies showed micromorphology of resorbed surface of roots of deciduous teeth. But, few studies compared physiological and pathological root resorption surfaces. In this study, we carefully observed microscopic morphologies of those two different root surfaces by scanning electron microscope and histologic features by light microscope. The resultant differences between physiologic and pathologic resorption surfaces of deciduous teeth were as follows: 1. The morphology of pathologic resorption lacunae due to inflammation varied in size and shape with irregular boundaries compared with the physiologic areas from scanning electron microscope observations. 2. From light microscope observations, several large resorption fossae containing numerous resorption lacunae were found, whereas the resorption lacunae were irregular in shape with pathologic resorption surface. 3. Numerous multinucleated giant cells were closely attached to the physiologic resorption lacunae, whereas several kinds of mesenchymal cells with numerous inflammatory cells were found in the areas adjacent to the pathologic resorption surface. 4. Light microscope findings showed that compensating cementum formation took place along some of the areas of inflammatory dentinal resorption. In conclusion, several morphological differences were present between physiologic and pathologic root resorption surfaces of human deciduous teeth. The future studies should include cytochemistry to clarify the cellular roles in resorption process observations of pulpal surfaces of coronal and radicular dentin to and the changes that occur in each phase of human deciduous tooth resorption.

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.3
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• pp.289-297
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• 2017

Local and general factors have been attributed to root resorption occurred by injuries such as trauma and dental caries that affect periodontal ligament or dental pulp tissue. Pathologic root resorption is different from physiologic root resorption in terms of resorption pattern such as micromorphology of resorption fossae and types of observed cells. Microscopic morphologies and histologic features of physiologic and pathologic root resorption surface of maxillary primary central incisors resulting from trauma and periapical inflammation were observed by scanning electron microscope and light microscope. The morphology of physiologic resorption lacunae was small and oval or circular shape with regularities. The morphology of pathologic resorption lacunae was large and polygonal shape with irregularities compared with the physiologic resorption lacunae. Multinucleated giant cells and mononuclear cells were closely attached to the physiologic and pathologic resorption lacunae, whereas several kinds of mesenchymal cells with numerous inflammatory cells were found in the areas adjacent to the pathologic resorption surface. Compensating cementum formation took place along some of the areas of physiologic and pathologic resorption area resulting from trauma, but could not be observed on pathologic resorption area resulting from periapical inflammation.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.4
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• pp.605-610
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• 2003

Physiologic root resorption occur from the apex of the primary teeth close to the permanent teeth towards the apex. Pathologic root resorption occur on surfaces of root due to causes such as trauma, replantation, orthodontic treatment, delayed or irregular eruption of teeth, or growing cysts or tumors. In children, the most frequently affected teeth from trauma are the maxillary primary central incisors. After such an event, root resorption initiate from the traumatized pulp or periodontium. In this case report, periapical radiographs were used to evaluate the features of pathologic root resorption by studying patients with history of trauma. The following results were noted. 1. Pathologic root resorption was observed in various patterns in all of the 10 traumatized maxillary primary central incisors. 2. Though teeth with pathologic root resorption were treated with pulpectomy, the resorption process continued to progress.

• The korean journal of orthodontics
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• v.35 no.2 s.109
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• pp.106-115
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• 2005

This study was aimed to investigate the effects of indomethancin on physiologic root resorption and to examine the dental pulp and tissue changes around the resorbing teeth 13-14 week old six mongrel dogs were divided into 3 groups, two experimental groups administered indomethacin 2mg/kg/day and 8mg/kg/day orally two times a day for 14 days respectively. and control group administered a placebo The deciduous incisors showing root resorption were selected. fixed for 24 hrs in $10\%$ formalin solution. demineralized in $10\%$ EDTA solution. Invested in paraffin and sectioned in $5{\mu}m$ thick sections. The preparations were stained with H&E staining and Masson's trichrome staining and examined under the light microscope Observation revealed that deciduous root resorbing tissue resembles inflammatory tissue and accompanies bore remodelling. The dental pulp was formal except the area near root resorption. well organized columnar odontoblasts layer under the predentin, anud the odontoblasts near root resorption were cuboidal or flat cells in the disrupted layer under the predentin. Indomethacin administered group showed a partial decrease in the number of odontoclasts and nucleus But there was no sign of pulp change by indomethacin. These results suggest that indomethacin inhibits recruitment of odontoclasts partially and that of osteoclasts more. and so when it is administered for long periods deciduous root resorption can be delayed and eruption of the successor can be delayed for a short period.

• Journal of the korean academy of Pediatric Dentistry
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• v.21 no.2
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• pp.439-455
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• 1994

The purpose of this study was to investigate the distribution of nerves in the periodontal ligament of a dog's primary teeth by each developing stage. The distribution of nerves in the periodontal ligament were investigated by means of immunohistochemistry for detection of neurofilament protein (NFP). The results were as follows: The NFP-immunoreactive nerve fibers were found to be densely distributed in the apical third of the periodontal ligament, while they were sparse in the coronal two third, in both primary and permanent teeth. In generally the density of distribution and degree of arborization of nerve fibers in periodontal ligament of primary teeth revealed a poor appearance compared with that of permanent teeth. Periodontal ligament in anterior teeth showed more abundant nerve innervation than posterior teeth, and the periodontal ligament of the bifurcation area in posterior teeth roots were not observed to have nerve fiber. The density of nerve distribution in the periodontal ligament of primary teeth was reduced according to the physiological root resorption and nerve fibers were not observed in the surrounding area on the root of the exfoliation stage in primary teeth. The distribution of nerve fibers in mucogingival tissue, was poor innervated according to the aging of the dogs. A more abundant distribution of nerve fiber was represented in the lingual mucogingival tissue than in the labial side. Most of the nerve endings in the periodontal ligament of primary teeth showed a tree-like appearance. However, the typical Ruffini-like nerve endings were not observed.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.2
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• pp.165-172
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• 2006

A direct pulp capping with different medicaments has been attempted for a long time. The most commonly used among those is the calcium hydroxide. In primary teeth, however, a success rate of direct pulp capping with calcium hydroxide has been reported to be lower than that of pulpotomy. The disappointing results of calcium hydroxide have prompted the search for other capping materials. Lately, several researchers suggested an application of adhesive resin-based composite systems as a capping material. They claimed that when an exposed vital pulp is capped directly with bonding resin, the pulp tissue is free of inflammation or necrosis without clinical symptoms. The aim of this study was to compare short-term effects of the bonding resin which was applied on the mechanically exposed vital pulp tissue and those of direct pulp capping with calcium hydroxide. The second objective was to compare success rates of the primary teeth which already underwent physiologic root resorption and those of the teeth which had not undergone physiologic root resorption yet, in each capping material groups. The vital, healthy pulp of forty-one primary teeth were exposed mechanically during a cavity preparation. They were divided into two groups: Group 1(n=21) underwent capping with bonding resin, and group 2(n=20) underwent capping with calcium hydroxide. Then these two groups were subdivided into two groups in each : the teeth which show physiologic root resorption and the teeth without root resorption. All of the sample teeth were restored with composite resin. Clinical evaluations such as percussion test, ice test, EPT, were recorded and also before- and after- standard x-ray films were compared and evaluated to decide whether the case was successful or not. Evaluation was performed at least 3 months after the capping materials. The results were as follows 1. There was no difference in success rate between group 1 and group 2. 2. Success rate of the teeth with physiologic root resorption was higher than that of the teeth without physiologic root resorption in group 1 and group 2. 3. There was no difference in success rate between anterior teeth and posterior teeth.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.1
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• pp.156-161
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• 2007

Pediatric dentists are frequently encountered with fractured root fragments of primary teeth caused either by the traumatic injuries or by the accidental fractures during the procedure of tooth extractions. In these situations, we often hesitate which method to choose, extract or retain it. In general, it is recommended to retain apical fragments, as the attempts to extract the apical fragments might harm the developing permanent tooth germ. This study was designed to ensure the validity of intentional retention of the root fragments of primary teeth in the situations described above. 6 children with intentionally root fragments who experienced root fracture in primary anterior teeth were available Periodic radiographic assessment was performed at 3 months interval for $7{\sim}37$ months. The results of this study showed that apical fragments had been resorbed through physiologic process in 5 patients. Apical fragment had been gingival emergence along with the erupting permanent tooth in 1 patient. There were no evidence of interference with eruption of permanent successors. In summary we have been ensured the validity of intentionally retention of the root fragments of primary teeth. Children with being remained apical root fragment should be recalled regularly for assessment and parents should be thoroughly informed about the situation with special emphasis on the necessity of periodic check-up.

• Journal of the korean academy of Pediatric Dentistry
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• v.40 no.3
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• pp.177-184
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• 2013

Calcium hydroxide mixture medicaments can nearly be considered to be the ideal primary tooth filling material. However, long-term application of calcium hydroxide combinations as an intra canal medicament softens dentin. The aim of this study was to evaluate the effect of calcium hydroxide on the microhardness of root dentin of primary tooth. For the study, 60 extractedprimary incisors were divided into 3 groups (no medicament, calcium hydroxide/iodorform mixture, and calcium hydroxide/distilled water mixture). After the cleansing and shaping of canals, calcium hydroxide medicaments were applied and stored for different periods of time (1, 7, 30, 90 days). The root was horizontally sectioned into 2 mm thick specimens and the microhardness was measured using Vickers microhardness tester. The results were as follows : Root dentin microhardness of primary teeth decreased with long term exposure to calcium hydroxide medicaments according to the experimental period and showed statistically significance (p < 0.05). Root dentin microhardness of primary tooth filled with calcium hydroxide mixed with distilled water showed more decrease than filled with Vitapex and showed statistically significance (p < 0.05). Root dentin microhardness of a control group without exposure to calcium hydroxide decreased according to the experimental period and showed statistically significance (p < 0.05).

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.3
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• pp.571-577
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• 2008

Root fracture of primary teeth is relatively uncommon because the more pliable alveolar bone allows displacement of the tooth. Root fracture of primary teeth is occupied $2{\sim}7%$ in trauma pattern of primary teeth. A horizontal root fracture is classified based on the location of the fracture in relation to the root tip : the apical third, middle third, or cervical third of the root. The prognosis worsens the further cervically the fracture has occurrer. Root fracture of primary teeth should be treated by splinting the incisor to the adjacent normal teeth with a resin-wire splint for $8{\sim}12$ weeks. However, if a portion of the root is abscessed or extremely mobile, it can be extracted, and the remaining root fragment will resorb normally. For coronal third fracture in primary teeth, the coronal third is extracted, leaving the apical portion of the root to resorb normally. These root fracture cases of primary teeth were treated by resin-wire splinting despite extremely mobile coronal fragment. Even though they seems like healing well, They need to be monitored regularly until their successors erupt.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.1
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• pp.126-131
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• 2005

The purpose of this study was to observe the potentiality of a mixture of antibiotics to relieve the endodontic and periapical infections in primary teeth. A mixture of metronidazole, ciprofloxacin, and minocyclin in distilled water or in a root canal sealer were used to disinfect the infected endodontic and periapical lesions. For application of this mixture, medication cavities were prepared at orifices of root canals by using the $Fissurotomy^{(R)}$ burs(S S White, USA). The cavities and bottom of pulp chamber were filled with antibiotics mixture. In this cases, clinical symptoms were improved following a single application of that mixture. Gingival swelling, pain, and fistulae were disappeared within a week. More long term evaluation will be needed. Although there were no reports of side effects, care should be taken if children are sensitive to antibiotics. Within the limitations of this case, the mixture of 3 antibiotics provided an excellent improvement in treatment of infected primary teeth under the physiologic root resorption.