• The Journal of Korea Assosiation for Disability and Oral Health
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• v.7 no.2
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• pp.99-102
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• 2011

A-12year-old boy visited the clinic with chief complaint of anterior maxillary trauma. He was diagnosed with first degree mental retardation and cerebral disorders. By clinical and radiographic examination, intrusion of maxillary central incisors were found. The intrusion was not severe, teeth were luxated with a slight force and the prognosis was followed. After the first year, external root resorption was seen radiographically. Due to difficult behavior management, one visit root canal filling with OrthoMTA(BioMTA, Korea) which is known to generate of cementum and periodontal ligament was planned along with general anesthesia. OrthoMTA was filled from the apex to 1-2mm below cervical area and composite resin used for crown restoration. 6 months after, further resorption, discoloration and mobility was not found. This case is currently checked yearly and further research is needed for inflammatory root resorption and ankylosis.

• Restorative Dentistry and Endodontics
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• v.39 no.4
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• pp.258-264
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• 2014

Objectives: This in vitro study aimed to investigate the ability of Candida albicans (C. albicans) and Enterococcus faecalis (E. faecalis) to penetrate dentinal tubules of instrumented and retreated root canal surface of split human teeth. Materials and Methods: Sixty intact extracted human single-rooted teeth were divided into 4 groups, negative control, positive control without canal instrumentation, instrumented, and retreated. Root canals in the instrumented group were enlarged with endodontic instruments, while root canals in the retreated group were enlarged, filled, and then removed the canal filling materials. The teeth were split longitudinally after canal preparation in 3 groups except the negative control group. The teeth were inoculated with both microorganisms separately and in combination. Teeth specimens were examined by scanning electron microscopy (SEM), and the depth of penetration into the dentinal tubules was assessed using the SMILE view software (JEOL Ltd). Results: Penetration of C. albicans and E. faecalis into the dentinal tubules was observed in all 3 groups, although penetration was partially restricted by dentin debris of tubules in the instrumented group and remnants of canal filling materials in the retreated group. In all 3 groups, E. faecalis penetrated deeper into the dentinal tubules by way of cell division than C. albicans which built colonies and penetrated by means of hyphae. Conclusions: Microorganisms can easily penetrate dentinal tubules of root canals with different appearance based on the microorganism size and status of dentinal tubules.

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.1
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• pp.20-27
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• 2017

This study aimed to assess microleakage of Endoseal MTA when it is used as a root canal sealer and a root canal filling material compared with conventional endodontic treatment materials Forty-two mature human permanent teeth with a single root canal were divided randomly into three experimental groups (n = 10) and two control groups (n = 6). Group A was obturated with AH $plus^{(R)}$ and gutta-percha (GP). Group E1 was obturated with Endoseal MTA and GP. Group E2 was obturated with Endoseal MTA only. The positive control group was obturated with GP only and the negative control group was obturated in the same way as the experimental groups. The samples were kept in saline solution for 24 hours and were immersed in 0.2% rhodamine B dye solution for 24 hours. Then the samples were split longitudinally and the micoleakage was assessed under a stereomicroscope. Complete microleakage was detected in all positive control group samples, whereas no microleakage was detected in the negative control group. There was no statistically significant difference between the experimental groups in the Kruskal-Wallis test. These results suggest that Endoseal MTA has potential use as a root canal sealer and a root canal filling material.

• The Journal of the Korean dental association
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• v.21 no.7 s.170
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• pp.539-542
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• 1983

• Restorative Dentistry and Endodontics
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• v.33 no.2
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• pp.107-114
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• 2008

This study was performed to assess the radiopacity of a variety of canal filling and retrograde root-end filling materials according to the specification concerning root canal obturation materials. Ten materials including Gutta-percha pellets, amalgam, Fuji II LC, $Dyract^{(R)}$ AP, Super $EBA^{(R)}$, $IRM^{(R)}$, AH $26^{(R)}$, $Sealapex^{TM}$, Tubli-$Seal^{TM}$, and dentin were evaluated in this study. In the first part, densitometric reading of an each step of aluminum step wedge on occlusal film were performed at 60 kVp (0.2, 0.3, 0.4 s), 70 kVp (0.2, 0.3, 0.33 s) to decide appropriate voltage and exposure time. In the second part, ten specimens which are 5 mm in diameter and 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 mm in thickness, were fabricated from each material studied. The specimens were radiographed simultaneously with an aluminum step wedge under decided condition (60 kVp, 0.2 s). The mean radiographic density values of the materials were transformed into radiopacity expressed equivalent thickness of aluminum (mm Al). The following results were obtained. 1. Among the various conditions including 0.2 s, 0.3 s, 0.4 s at 60 kVp and 0.2 s, 0.3 s, 0.33 s at 70 kVp, the appropriate voltage and exposure time that meet the requirement of density from 0.5 to 2.0 was 0.2 s at 60 kVp. 2. All of the materials in this study had greater radiopacity than the minimun level recommended by ISO No. 4049 standards. 3. Most of the materials had greater radiopacity than 3 mm Al requirement of ANSI/ADA specification No. 57 (2000) and ISO No. 6876 (2001) standards except for Fuji II LC and Dyract. It suggests that all experimental canal filling and retrograde root-end filling materials have a sufficient radiopacity that meet the requirement concerning root canal obturation materials except for Fuji II LC and Dyract.

• Restorative Dentistry and Endodontics
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• v.9 no.1
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• pp.25-35
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• 1983

The purpose of this study was the observe the toxic effects of root canal sealers in 108 white rats. Experimental animals were divided into control and experimental groups. Theree representative types of materials, such as AH26, Z.O.E. and F.R. were used in this study. Cavities were prepared on the left mandibular area of 108 white rats. Three different sealers were placed in as experiment and bone cavities were left without filling as control. The experimental animals were sacrificed by cervical dislocation at the intervals of 1, 3, 7, 14, 28 and 49 days after filling. Each specimen was fixed with 10% neutral formalin solution, decalcified with 5% nitric acid, embedded in paraffin and sectioned 5-7${\mu}$. in thickness. The paraffin sections stained with Hematoxylin - Eosin were observed through the ordinary light microscope. The results were as follows; 1. Slight toxic effect to surrounding tissue were found in every experimental specimen. 2. AH26 showed the highest inflammatory response, and F.R. showed the lowest inflammatory response which subsided and replaced by fibrosis at 4 weeks after filling. 3. The cavity filled materials, such as implanted root canal sealers, blood clots and necrotic tissue, showed a tendency to be absorbed gradually proportioned to the experimental periods. A small amount of cavity filled materials were observed in the bone cavities after 4 weeks. 4. Fibroblastic proliferation began to produce fibrous capsule around the bone cavity in 2 weeks after filling. Fibrosis was prominent at 4 weeks after filling. 5. Osteoblastic activity of surrounding bone was observed at first in 2 weeks after filling and prominent in 4 weeks after filling. Osteoblastic activity showed an increasing effect as the time prolonged. 6. Surrounding tissue of the bone cavities showed the features of tissue destruction and had very severe inflammatory response at an initial stage. Above-mentioned appeared to be recovered gradually proportioned to the experimental periods.

• Journal of Oral Medicine and Pain
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• v.6 no.1
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• pp.15-18
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• 1981

The author had selected the roots and root-canal as measurable parts and sought the area ratio by measuring the respective areas of the root. Further, heplotted out a root caual index and studied the correlation with age. The teeth used as reserch material were permanent maxillary central incisors of Korean female. Some 296 teeth of known age were selected on condition that there is no caries or filling material and that they were not malformed in showing normal signs in roentgenograms. The $3" {\times} 4"$ printing paper so as to measure easily. On the ocassion of measureing the area of measured parts with a planimeter (Koizumi, type kp-27, Japan), the cervical lines were joined up into a straight line on a photograph (Figure 1) Root canal index = Area of the root / Area of the root canal The results of the root canal index in Korean female age groups were as follows : 1. The root canal index of maxilary central incisor in women was 4.74 im 20 years of age, 5.44 in 30, 5.90 in 40, 6.32 in 50, 6.63 in 60 in the order. 2. Root canal index and age were in positive correlation ; there was a tendency that the root canal index increase as age advances. 3. The regression equation was as follows : Y = 5.36x + 7.71 (r = 0.54, n= 296 ) (Y = estimated age, x = root canal index)

• The Journal of the Korean dental association
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• v.21 no.2 s.165
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• pp.167-172
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• 1983

This study was to investigate the effects of mynol cement on the periapical tissues of 40 molars in ten dogs. Root canal fillings were placed with mynol cement and the animals were killed at different post operative periods ranging from 1 to 5 weeks. The teeth examined on the basis of microscipic findings. The following results may be drawn; 1. 1 week after root canal fillings, the necrosis of cementum and dentin including alveolar bone was to be seen. There were severe inflammatory changes in the periodontal ligament. 2. 2 weeks after root canal fillings, edematous changes and fibrosis in the periodontal ligament were revealed. 3. After 3-4 weeks, fibrosis was more prominent than 2 weeks. 4. 5 weeks after root canal fillings, the osteoblastic activity was found abundantly surrounding the alveolar bone.

• Restorative Dentistry and Endodontics
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• v.8 no.1
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• pp.155-159
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• 1982

The author has studied comparatively the sealing quality of conventional Z.O.E. cement, chloropercha and FR cement by means of penetration of 2% methylene blue solution through the apex of human teeth in 112 cases as the time elapsed. The results were as follows; 1. All the specimen, of which dye immersion time is three days, showed dye penetration of low degree unrelated to the kinds of root canal cement and the degree of dye penetration was increased as the time elapsed. 2. Of all the experimental group, the Z.O.E. cement group showed the lowest degree of dye penetration and the FR filling group showed the highest degree of dye penetration. 3. The degree of dye penetration of FR cement group was higher than that of the Z.O.E. cement group but lower than that of the chloropercha group.

• Journal of Korean Dental Science
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• v.14 no.2
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• pp.61-68
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• 2021

Purpose: The aim of this study was to investigate the outcomes of endodontic treatment of mandibular second molar with C-shaped canal in elderly patients and related factors affecting the survival of the tooth. Materials and Methods: From 2010 to 2015, the survival rate following endodontic treatment was evaluated in elderly patients over 60 years who visited the Veterans Health Service Medical Center for endodontic treatment. The presence of C-shaped canals was confirmed using clinical records and radiographic features. Patient's age, sex, systemic diseases, tooth location, vitality, signs and symptoms, fractures, caries, apical radiolucency, canal shaping methods, sealer leakage, filling voids, and restoration of prosthesis were included in the analyses as confounding variables. The survival rate of teeth was analyzed using Kaplan-Meire analysis and the relationship between the survival rate and variables was analyzed using Simple and Multiple Cox regression analysis. Result: In total, 107 teeth in elderly patients had C-shaped canal. The survival rate of teeth that received endodontic treatment was 63.70%. None of the factors investigated significantly influenced the survival rate (P>0.05). Conclusion: In elderly patients with C-shaped canal, the survival rate after root canal treatment was not significantly different from that of other mandibular molars.