• Journal of Korean Dental Science
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• v.5 no.2
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• pp.60-67
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• 2012

Purpose: To test the apical leakage prevention performance of three different materials through protein leakage procedures using bovine serum albumin (BSA) and Bradford protein reagent. Materials and Methods: A total of 60 human single-rooted teeth were divided into 4 groups, and conventional root canal filling was done. The root was cut 3 mm from the apex, and a cavity was formed. Proroot MTA (MTA), Fuji II LC (GI), Fuji II LC with XP bond (GIA), and Caviton (CA) were used as experimental materials to fill the cavity in a retrograde filling manner. The extent of BSA leakage was then measured with a ultraviolet visible spectrophotometer 24, 48, and 72 hours after filling. Result: After 24 hours, among the 15 teeth of each group, 2 in MTA, 4 in GI, 3 in GIA, and 7 in CA showed leakage. After 48 hours, 3 in MTA, 5 in GI, 5 in GIA, and 10 in CA had leakage and discoloration. After 72 hours, among the 15 teeth of each group, 3 in MTA, 6 in GI, 5 in GIA, and 10 in CA showed leakage. The leakage in the CA group was greater than that in the MTA group at 48 and 72 hours based on Fisher's exact test (P=0.025), and the difference was statistically significant. Similarly, the leakage in the CA group was greater than that in the MTA group over time based on the Kaplan-Meier survival estimate (P=0.011), and the difference was statistically significant. Conclusion: Glass ionomer, glass ionomer after adhesive application, and MTA all showed leakage. Caviton showed greater leakage compared to MTA 48 and 72 hours after filling, and the difference was statistically significant; thus suggesting that Caviton is not appropriate as retrograde filling material considering its sealing ability.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.28 no.2
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• pp.471-489
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• 1998

For the successful endodontic treatment, root canal should be cleaned thoroughly by accurate mechanical and chemical canal preparation and sealed completely with canal filling material without damaging the periapical tissues. The accuracy of the root canal length measurement is a prerequisite for the success of the endodontic treatment, and the root canal length is often determined by the standard periapical radiographs and digital tactile sense. In this study, the accuracy and the clinical usefulness of Digora/sup (R)/, an intraoral digital imaging processor and the conventional standard radiographs were compared by measuring the length from the top of the file to the root apex. 30 single rooted premolars were invested in a uniformly sized blocks and No.25 K-file was inserted into and fixed in each canal. Each block was placed in equal distance and position to satisfy the principle of the bisecting angle and paralleling techniques and Digora/sup (R)/ system's image and standard periapical radiographs were taken. Each radiograph was examined by 3 different observers by measuring the length from top of the file to the root apex and each data was compared and analyzed. The results were as follows; 1. In the bisecting angle technique, the average difference between the Digora/sup (R)/ system and standard periapical radiograph was 0.002 mm and the standard deviation was 0.341 mm which showed no statistically significant difference between the two systems(p>0.05). Also, in the paralleling technique, the average difference between these two system was 0.007 mm and the standard deviation was 0.323 mm which showed no statistically significant difference between the two systems(p>0.05). 2. In Digora/sup (R)/ system, the average difference between the bisecting angle and paralleling technique was -0.336 mm and the standard deviation was 0.472 mm which showed a statistically significant difference between the two techniques(p<0.05). Also, in the standard periapical radiographs, the average difference between the bisecting angle and paralleling technique was 0.328 mm and the standard deviation was 0.517 mm which showed a statistically significant difference between these two techniques(p<0.05). 3. In Digora/sup (R)/ system and the standard periapical radiographs. there was a statistically significant difference between the measurement using the bisecting angle technique and the actual length(p<0.05), But there was no statistically significant difference between the measurement using the paralleling technique and the actuallength(p>0.05). In conclusion. the determination of the root canal length by using the Digora/sup (R)/ system can give us as good an image as the standard periapical radiograph and using the paralleling technique instead of the bisecting angle technique can give a measurement closer to the actual canal length. thereby contributing to a successful result. Also. considering the advantages of the digital imaging processor such as decreasing the amount of exposure to the patient. immediate use of the image. magnification of image size. control of the contrast and brightness and the ability of storing the image can give us good reason to replace the standard periapical radiographs.

• Restorative Dentistry and Endodontics
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• v.24 no.3
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• pp.503-510
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• 1999

The purpose of this study was to evaluate the amount of transportation of original canal, zip formation, permanent deformation and fracture of instruments after canal enlargement. In this study, the 60 resin blocks that have curved canals were randomly divided into 3 experimental groups with 20 teeth each according to instrument types and filling methods for canal enlargement. The curved canals of each experimental groups were enlarged to No 40 ISO size with the K-flexo stainless steel file (Group 1), Engine-driven Ni-Ti Profile new series(Group 2) and Engine-driven Ni-Ti Quantec 2000 series(Group 3) according to the manufacturer's recommendation. Pre- and postoperative X-rays were taken at same position and the films were scanned and the canal images were traced to determine the canal curvature according to the method of Schneider. The amount of reduction in canal curvature were calculated between pre- and postoperative X-rays. In addition to zip formation, permanent deformation and fracture of instruments were examined after canal enlargement. The results were as follows : 1. All experimental groups showed some loss of canal curvature after instrumentation. There was a significant change in curvature between before and after instrumentation in each group(p<0.001). 2. Engine-driven Ni-Ti instrumentations resulted in an average loss of curvature of 2.36 degrees for Profile new series, 3.43 degrees for Quantec series, and hand instrumentation showed an average loss of curvature of 6.48 degrees for K-flexo file. There was a statistical significant difference between hand instrumentation and engine-driven Ni-Ti instrumentations(p<0.05). But there was no statistical difference between Profile new series and Quantec series. 3. There were many apical zip formations in group 1(Hand instrumentation). But there were no apical zip formations in group 2,3(Engine-driven Ni-Ti instrumentation). 4. The instrument deformation occured 9 cases in group 1(K-flexo file), 2 cases in group 2(Profile new series) and 3 cases in group 3(Quantec) after instrumentation. And the instrument fracture occured 1 case in each group. The results showed that the engine-driven Ni-Ti instruments, if we use carefully according to manufacturer's recommendations, can be use effectively for instrumenting the curved root canals in case of the MAF was over size 40.

• Restorative Dentistry and Endodontics
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• v.9 no.1
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• pp.127-132
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• 1983

The purpose of this study was to examine the sealing ability of the vitapex, when used with gutta-percha cone, as a root canal filling material. Fourty five canals from extracted human maxillary and mandibular teeth were randomly selected and instrumented in a conventional method with k-file. After instrumentation and dry the canal with paper points, the canals were divided into three groups and fifteen canals in each group were filled with the following materials; Vitapex, Vitapex in combination with gutta-percha cone, and Gutta-percha cone and Zinc-oxide Eugenol Cement. All the specimens were immersed in 2% methylenblue dye solution and the depth of dye penetration into the canals were evaluated by macroscope at the intervals of 1 day, 2days and 7days. The following results were obtained; 1. All the materials experimented showed varying degrees of dye penetration. 2. The canals filled with Vitapex and Vitapex in combination with gutta perch a cone revealed sudden increase of dye penetration with time passage compared to the canals obturated with Gutta-percha cone and Zinc-oxide eugenol cement. 3. In the canals filled with Vitapex, the mean dye penetration was 1.6mm at 1day, but the specimen exposed to the dye for 7days showed mean dye penetration of 9.2mm. 4. In the canals obturated with Vitapex and gutta-percha cone, the mean dye penetration was 2mm at 1day, 2.2mm at 2days, and 8mm at 7days.

• Restorative Dentistry and Endodontics
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• v.45 no.4
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• pp.43.1-43.9
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• 2020

A variety of therapeutic modalities can be used for the endodontic treatment of a traumatized tooth with internal root resorption (IRR). The authors present a case report of the successful restoration of a traumatized upper central incisor that was weakened due to severe IRR and subsequent periapical lesion formation. A 20-year-old female patient was referred to our clinic with severe internal resorption and subsequent periapical pathosis destroying the buccal bone wall. Root canal treatment had been initiated previously at another dental practice, but at that time, the patient's condition could not be managed even with several treatments. After cone-beam computed tomography imaging and proper chemomechanical cleaning, the tooth was managed with a mineral trioxide aggregate plug followed by root canal filling using short fiber-reinforced composite, known as the Bioblock technique. This report is the first documentation of the use of the Bioblock technique in the restoration of a traumatized tooth. The Bioblock technique appears to be ideal for restoring wide irregular root canals, as in cases of severe internal resorption, because it can uniquely fill out the hollow irregularities of the canal. However, further long-term clinical investigations are required to provide additional information about this new technique.

• 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.

• Restorative Dentistry and Endodontics
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• v.21 no.2
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• pp.628-634
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• 1996

The purpose of this study was to investigate the effect of moisture on apical sealing properties of root canal. Fifty five single rooted human teeth were selected from maxillary and mandibular teeth. After removing crown portion at the cemento-enamel junction, all teeth were routinely prepared with step-back method. And then, the canals were dried with paper point and the teeth were randomly divided into 3 groups of 15 teeth each, and remaining 10 teeth were used as positive and negative control teeth : Group 1 were irrigated with 1ml of 95% alcohol and dried with air and paper point. Group 2 and 3 were intentionally contaminated with 0.05ml of 3.5% NaOCl or saliva, respectively. All the teeth were obturated with sealapex and gutta percha cone by lateral condensation technique, and covered with two coat of nail varnish after 48 hours of obturation. The teeth were immersed in india ink for 1 week and cleaned with methyl salicylate and then the degree of dye penetration were measured with stereomicroscope. The data were analyzed statistically by one-way ANOVA. The results were as follows : 1. All experimental groups showed varying degrees of dye penetration, and the mean degree of dye penetration was 0.1mm to 0.7mm. 2. Saliva contamination group(group 3) showed the highest amount of dye penetration, followed by NaOCl contamination group, then alcohol dried group, but there was no significant difference among three experimental groups. * This results suggest that there was no significant differences of apical leakage after canal obturation between alcohol dried canal and moisture present canals and the use of alcohol instead of paper point is unnecessary to dry the canals prior to canal filling. But other factors such as bacterial contamination and sealer discoloration by moisture must be considered in application of this results to clinical practice.

• Proceedings of the KACD Conference
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• 2003.11a
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• pp.600-600
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• 2003

I. Objectives Effective endodontic obturation must provide a complete, three-dimensional filling of the root canal system, preventing the communication of fluids between root canal and surrounding periapical tissues. The objective of this study was to compare the apical leakage with or without the use of dentin adhesive system. II. Materials and Methods Forth extracted human teeth with single canals were decoronated. Root canals were instrumented using GT rotary files and Profile .04 file up to #40, 1mm short of the apex. After each instrumentation, copious irrigation with 5.25% sodium hypochlorite solution and confirmation of apical patency were performed.(omitted)

• Restorative Dentistry and Endodontics
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• v.19 no.2
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• pp.461-472
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• 1994

The purpose of this study was to evaluate the sealing ability according to types of spreader and compatibility of accessory cone used in lateral condensation method. 120 plastic blocks with canal preformed were instrumented with K-,H-files and Gates-Gllidden bur. Shaped plastic blocks were divided into six experimental groups according to spreader and accessory cone used in lateral condensation. Then they were obturated by lateral condensation method without -sealer. Six experimental groups were as follows: Group 1 : Filling with #30 spreader & #25 gutta-percha cone Group 2 : Filling with #30 spreader & Fine accessory cone Group 3 : Filling with #3 spreader & #25 gutta-percha cone Group 4 : Filling with #3 spreader & Fine accessory cone Group 5 : Filling with #20,#30 spreader & #25 gutta-percha cone Group 6 : Filling with #2, #3 spreader & Fine accessory cone All the blocks were stored in 100% humidor at room temperature for 2 days. Each block was placed in centrifuged for 20 minutes at 3,000 rpm. Apical leakage was mesured from the apical foramen to the most coronal level of- dye leakage in millimeter under a stereoscope. The data were analysed by ANOVA. The obtained results were as follows; 1. In groups using two spreaders(Group 5,6), the linear leakage was less than one spreader using groups(Group 1-4). 2. Tn groups using two spreaders(Group 5,6), there was no significant difference in linear leakage between standardized -spreader group and non standardized group (p>0.01). 3. When one spreader was used(Group 1-4), standardized-spreader groups showed less linear leakage than nonstandardized spreader groups(P<0.01). 4. In case of using same spreader(Groupl,2 & Group 3,4), there was no significant difference in linear leakage according to accessory cone type. 5. It needs to use one more spreaders to increase apical sealability.

• Restorative Dentistry and Endodontics
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• v.31 no.4
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• pp.323-329
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• 2006

The aim of this study was to evaluate the retrievability of Resilon as a root canal filling material Twenty-seven human single-rooted extracted teeth were instrumented utilizing a crown down technique with Gates-Glidden burs and ProFile system. In group1 (n = 12) canals were obturated with gutta percha and AH-26 plus sealer using a continuous wave technique and backfilled. In group 2 (n = 15) Resilon was used as a filling material. Then teeth were sealed and kept in $37^{\circ}C$ and 100% humidity for 7 days. For retreatment, the samples were re-accessed and filling material was removed using Gates-Glidden burs and ProFiles. Teeth were sectioned longitudinally to compare the general cleanliness and amount of debris $({\times}\;75)$ using SEM. Chi-square test was used $({\alpha}\;=\;0.05)$ to analyze the data. The total time required for removal of filling materials was expressed as mean ${\pm}SD$ (min) and analyzed by the Student t-test $({\alpha}\;=\;0.05)$, Required time for retreatment was $3.25\;{\pm}\;0.32$ minutes for gutta percha/ AH 26 plus sealer and $3.05\;{\pm}\;0.34$ minutes for Resilon. There was no statistically significant difference between the two experimental groups. There was no significant difference between the groups in the cleanliness of the root canal wall. This study showed that Resilon was effectively removed by Gates-Glidden burs and ProFiles.