• Restorative Dentistry and Endodontics
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• 제9권1호
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• pp.59-68
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• 1983

The purpose of this study was to examine the influence of canal irrigants and the method of canal filling on the quality of canal obturation. Sixty extracted human teeth with single root were selected and divided into three different groups; In group I (control); 5 cc normal saline irrigated after each instrumentation In group II; 2.5 cc-3% NaOCl in combination with 2.5 cc-3% $H_2O_2$ In group III; RC-Prep in combination with 5 cc-3% NaOCl All specimens were cleaned, shaped(#50 file size), irrigated and obturated by lateral condensation and automated thermatic condensation filling method of gutta-percha and AH-26. After all the specimens were immersed in 2% methylene blue dye solution in $37^{\circ}C$ for 7 days and the degree of dye penetration into the canals observed by magnifying glass(${\times}$20) and reflected light microscope The results were as follows: 1. All the the teeth showed some degree of the dye penetration. 2. There were no significant difference among three groups in the degree of the dye penetration in each canal filling method. 3. There were no significant difference of the dye penetration between each canal filling method in group I. 4. There were no statistically significant difference of the dye penetration between each canal filling method in group II and group III, but lateral condensation group was showed slightly more than automated thermatic condensation group.

• 치과방사선
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• 제27권2호
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• pp.15-25
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• 1997

This study was performed to prepare the quantitative method of judging the sensitive prognosis of chronic apical periodontitis as early as possible. The subjects were 25 cases with periapical radiolucencies of which were treated with endodontic treatment. Serial radiographs were taken by standardized method longitudinally. The density slice function of digital radiographic system were employed for quantitative and longitudinal assessment of the radiolucent area and the condensing osteitis simultaneously. Obtained results were as follows: 1. The amount of bone repair after endodontic treatment could be detected quantitatively by the density slice function of digital radiographic system. 2. Within the 6-week period after root canal filling, the prognosis could be evaluated by assessment both radiolucent area and condensing osteitis on digital radiographic system. 3. The pattern of bone repair showed peripheral type in most cases from the 6th week after root canal filling. 4. In longitudinal change, bone repair showed two patterns; the succeeding reduction of radiolucent area showing the increase of condensing osteitis in size till 6th week and following by static state or reduction tendency and the reduction following the initial increase of both areas. 5. Cases with pulpitis by trauma showed initial increase of condensing osteitis at 2nd week, marked reduction of radiolucent area and condensing osteitis at 6th week, and approximately normal bone state at 8th week after root canal filling.

• Restorative Dentistry and Endodontics
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• 제43권1호
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• pp.5.1-5.9
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• 2018

Objectives: This study evaluated the amount of remaining root canal filling materials after retreatment procedures performed by undergraduate students using manual, rotary, and reciprocating techniques through micro-computed tomographic analysis. The incidence of instrument fracture and the instrumentation time were also evaluated. Materials and Methods: Thirty maxillary single rooted teeth were prepared with Reciproc R25 files and filled with gutta-percha and AH Plus sealer by the continuous wave of condensation technique. Then, the specimens were assigned to 3 groups (n = 10), according to the retreatment technique used: manual, rotary, and reciprocating groups, which used K-file, Mtwo retreatment file, and Reciproc file, respectively. Retreatments were performed by undergraduate students. The sample was scanned after root canal filling and retreatment procedures, and the images of the canals were examined to quantify the amount of remaining filling material. The incidence of instrument fracture and the instrumentation time were recorded. Results: Remaining filling material was observed in all specimens regardless of the technique used. The mean volume of remaining material was significantly lower in the Reciproc group than in the manual K-file and Mtwo retreatment groups (p < 0.05). The time required to achieve a satisfactory removal of canal filling material and refinement was significantly lower in the Mtwo retreatment and Reciproc groups (p < 0.05) when compared to the manual K-file group. No instrument fracture was observed in any of the groups. Conclusions: Reciproc was the most effective instrument in the removal of canal fillings after retreatments performed by undergraduate students.

• Restorative Dentistry and Endodontics
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• 제49권1호
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• pp.5.1-5.11
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• 2024

Objectives: This study aimed to present the results and analyses of clinical trials, including updates on the different functions of root canal sealers. Materials and Methods: In June 2023, we performed a comprehensive search of ClinicalTrials.gov to identify interventional clinical trials pertaining to root canal sealers. In total, 23 clinical trials conducted up to June 2023 were included in this study. Results: Approximately half of the trials (11 out of 23) were completed, while none were terminated or withdrawn. Each included trial had a minimum of 10 participants, with 11 trials having more than 100 participants. None of the assessed trials provided outcomes, and the majority (17 out of 23) lacked associated publications. In terms of geographic distribution, the USA and Canada did not contribute to any root canal sealer trials. Conclusions: This study highlights the lack of diversity in trial locations, the absence of reported results, and a scarcity of clinical trials examining the physicochemical properties of different sealers. Most published trials primarily focused on assessing the post-operative pain effect of these sealers, but no significant difference was found regarding post-operative pain control.

• Restorative Dentistry and Endodontics
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• 제23권1호
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• pp.346-356
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• 1998

The purpose of this study was to evaluate the sealing ability of various canal filling methods. Palatal roots of ninety extracted human maxillary molar teeth were resected at cementoenamel junction. Eighty of them were randomly assigned to four experimental groups, ten were served as positive and negative controls. All canals were prepared to # 40 using Profile. Experimental groups were obturated by lateral condensation technique, Thermafil technique, Continuous Wave of Condensation Technique, and down-pack & back-fill technique of Obtura-II, each with root canal sealer. Control groups were not obturated. Teeth were immersed in resorcinol-formaldehyde resin for 5 days at $4^{\circ}C$, and the resin was allowed to polymerize completely for 4 days at room temperature. Teeth were then ground horizontally at 1.5mm(level 1), 2.5mm(level 2), 3.5 mm(level 3) from the anatomical apex and examined with a stereomicroscope at ${\times}40$ magnification. The gap between the canal wall and the filling material, which was filled with the resin, was measured at each of the three levels. Each ratio of leakage was obtained by calculating the ratio of the area of the resin to the total area of the canal and was analyzed statistically (Rank-sum test). The results were as follows : 1. At the level 1, there was the greatest leakage in the Thermafil group and Obtura-II group, and the difference between the Obtura-II group and Continuous Wave of Condensation Technique group was statistically significant(p<0.05). 2. At the level 2, there was the least leakage in the Continuous Wave of Condensation Technique group, but there was no statistically significant difference between each group (p>0.05). 3. At the level 3, there was no statistically significant difference between each group(p>0.05).

• 대한치과의사협회지
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• 제55권8호
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• pp.556-564
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• 2017

Endodontic surgery is a procedure to treat apical periodontitis or abscess in cases that did not heal after nonsurgical treatment or retreatment. This might include situations with persistent intracanal infection after root canal treatment. Other reasons might be found in extraradicular infection, such as bacterial biofilm on the apical root surface or bacteria within the lesion. For many years, the treatment standard was the traditional approach with surgical burs and amalgam for root-end filling. Endodontic microsurgery is the most recent step in the evolution of endodontic surgery, applying not only ultrasonic tip and biocompatible filling materials but also incorporating high-power magnification and illumination. Although many studies have been published that advocate the use of modern technique, the traditional techniques are still widely used in the surgery community. The purpose of this study was to demonstrate the endodontic microsurgery procedure including the root-end preparation and filling with the use of a surgical operating microscope.

• Restorative Dentistry and Endodontics
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• 제28권6호
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• pp.449-456
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• 2003

The purpose of this study is to evaluate the sealing effect of several root-end filling materials using spectrophotometric analysis. 180 single root teeth with one canal were instrumented and canal filled. Root resected and root end preparation was made. Teeth were randomly classified to S experimental group(MTA, EBA, IRM, TCP, ZOE) and 1 control group according to root-end filling material MTA group used PRO ROOT MT A, EBA group used Super EBA. TCP group used NEW APATITE LINER TYPE II main component of which is ${\alpha}-tricalcium$ phosphate (TCP). According to manufacture's instruction experimental material was mixed and retrfilled. After 2% methylene blue solution penetration absorbance for each test sample was measured with spectrophotometer (JASCO UV-530, Japan). The mean absorbance of control and experimental group was as follows; MTA: 0.092, IRM: 0.226, Super EBA: 0.255, ZOE: 0.374, Control: 0.425, TCP: 0.501 and the result analyzed by Turkey test at P=0.05 level. Conclusions of this study are as follows; 1. The absorbance increase in following sequence MTA, IRM, Super EBA, ZOE, Control. TCP. 2. MTA showed the least leakage but was not significant with IRM or Super EBA and was significant with control or TCP(p<0.05). 3. TCP had the most leakage and was not significant with control group.

• Restorative Dentistry and Endodontics
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• 제23권1호
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• pp.366-378
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• 1998

Thermocondensation root canal filling technique have been used to fill accessary canals or to obtain homogeneous root caral fillings. But these thermocondensation technique inevitably produce heat in the canal which can be transmitted through the dentin and cementum and consequently damage periodontal ligamental cells and osteoblasts. In this study, System $B^{TM}$(Analytic technology, WA.D.S.A.) was used to evaluate the reaction of periodontal ligament tissue to "Continous Wave condensation technique" introduced by Buchanan, and the transmitted root surface temperature was measured according to measured root thicknesses. 12 Mandibular incisors of two adult dogs were used for the experiment. 6 controls were filled by lateral condensation technique with sealer.3 specimens were apically filled by Continuous Wave technique at $200^{\circ}C$ for 5 seconds and remaining 3 specimens were additionally backfilled using System $B^{TM}$(Analytic technology, WA.D.S.A.) was used to evaluate the reaction of periodontal ligament tissue to "Continous Wave condensation technique" introduced by Buchanan, and the transmitted root surface temperature was measured according to measured root thicknesses. 12 Mandibular incisors of two adult dogs were used for the experiment. 6 controls were filled by lateral condensation technique with sealer.3 specimens were apically filled by Continuous Wave technique at $200^{\circ}C$ for 5 seconds and remaining 3 specimens were additionally backfilled using System $B^{TM}$ at $100^{\circ}C$ for 20 seconds. Six weeks later, the dogs were sacrificed and the teeth stained with Hematoxylin and Eosin for histologic examination. 6 extracted human teeth were used to measure the transmitted temperature. After cutting off the crown, the canals were prepared and divided into 3 groups with root thickness of 1.5mm, 1.0mm, 0.5mm, 2 teeth in each group. Inside each root canal, System $B^{TM}$ was heated as with the temperature for the apically condensed and the back filled group, and the transmitted heat was measured on the external surface of the root. The temperature of System $B^{TM}$ heat spreader at $200^{\circ}C$ and $100^{\circ}C$ was also measured at root temperature. It can be concluded as follows: 1. In the thin area (200-$250{\mu}m$) of the root, root resorption could be seen even with heating at $200^{\circ}C$ for 5 seconds. 2. When the spreader was heated at $200^{\circ}C$ for 5 seconds and additionally at $100^{\circ}C$ for 20 seconds for backfill, all teeth showed root resorption regardless of their root thickness. 3. The transmitted external root surface temperature was higher as the root thickness decreased and as the heating time increased. In the thermocompaction technique using System $B^{TM}$, the spreader should be heated for the minimal time and used only in the apical area. The heated spreader shouldn't inserted to the binding point of the canal and backfilling should be done with other means of minimally heated gutta percha technique.

• Restorative Dentistry and Endodontics
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• 제46권1호
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• pp.13.1-13.9
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• 2021

Objectives: This study aimed to evaluate and compare the efficacy of the S1 reciprocating system and the D-Race retreatment rotary system for filling material removal and the apical extrusion of debris. Materials and Methods: Sixty-four freshly extracted maxillary canines were shaped with size 10 and size 15 K-files, instrumented using ProTaper Gold under irrigation with 2.5% sodium hypochlorite (NaOCl), obturated according to the principle of thermo-mechanical condensation with gutta-percha and zinc oxide eugenol sealer, and allowed to set for 3 weeks at 37℃. Subsequently, the teeth were divided into a control group (n = 4), the D-Race rotary instrument group (n = 30), and the S1 reciprocating instrument group (n = 30). After classical retreatment, the canals were subjected to a complementary approach with the XP-Endo Shaper. Desocclusol was used as a solvent, and irrigation with 2.5% NaOCl was performed. Each group was divided into subgroups according to the timing of radiographic readings. The images were imported into a software program to measure the remaining filling material, the apical extrusion, and the root canal space. The data were statistically analyzed using the Z-test and JASP graphics software. Results: No significant differences were found between the D-Race and S1 groups for primary retreatment; however, using a complementary cleaning method increased the removal of remnant filling (p < 0.05). Conclusions: Classical removal of canal filling material may not be sufficient for root canal disinfection, although a complementary finishing approach improved the results. Nevertheless, all systems left some debris and caused apical extrusion.

• Imaging Science in Dentistry
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• 제52권3호
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• pp.245-258
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• 2022

Purpose: This study compared the root canal anatomy between cone-beam computed tomography (CBCT) and micro-computed tomography (micro-CT) images before and after biomechanical preparation and root canal filling. Materials and Methods: Isthmus-containing mesial roots of mandibular molars(n=14) were scanned by micro-CT and 3 CBCT devices: 3D Accuitomo 170 (ACC), NewTom 5G (N5G) and NewTom VGi evo (NEVO). Two calibrated observers evaluated the images for 2-dimensional quantitative parameters, the presence of debris or root perforation, and filling quality in the root canal and isthmus. The kappa coefficient, analysis of variance, and the Tukey test were used for statistical analyses(α=5%). Results: Substantial intra-observer agreement (κ=0.63) was found between micro-CT and ACC, N5G, and NEVO. Debris detection was difficult using ACC (42.9%), N5G (40.0%), and NEVO (40%), with no agreement between micro-CT and ACC, N5G, and NEVO (0.05<κ<0.12). After biomechanical preparation, 2.4%-4.8% of CBCT images showed root perforation that was absent on micro-CT. The 2D parameters showed satisfactory reproducibility between micro-CT and ACC, N5G, and NEVO (intraclass correlation coefficient: 0.60-0.73). Partially filled isthmuses were observed in 2.9% of the ACC images, 8.8% of the N5G and NEVO images, and 26.5% of the micro-CT images, with no agreement between micro-CT and ACC, and poor agreement between micro-CT and N5G and NEVO. Excellent agreement was found for area, perimeter, and the major and minor diameters, while the roundness measures were satisfactory. Conclusion: CBCT images aided in isthmus detection and classification, but did not allow their classification after biomechanical preparation and root canal filling.