• Restorative Dentistry and Endodontics
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• v.18 no.2
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• pp.497-500
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• 1993

Sealapex was compaired with a zinc oxide eugenol sealer over a 24 - wk interval to examine solubility in an in vitro situation. After obturation with gutta percha and the appropriate sealer, speciemens were immediately immersed in a saline solution to challenge the solubility of the sealers. The solutions were changed weekly to allow for a continued dissolution of the sealers. After immersed in methylene blue solution for 3 days, the speciemens were made transparent by a clearing process. Microscopic examination was used to determine the linear penetration of dye for each speciemen. Result revealed that sealapex had no greater dissolution than ZOE(P<0.05).

• Restorative Dentistry and Endodontics
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• v.15 no.1
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• pp.81-87
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• 1990

The purpose of this study was to evaluate the apical seal produced by low temperature($70^{\circ}C$) injection gutta percha technique(ULTRAFIL) with & without sealer, warm latero-vertical cindensation technique (ENDOTEC) with & without sealer, and the lateral condensation technique with sealer. 100 extracted, single rooted human teeth were divided into 5 groups and root canals were enlarged & obturated according to the purpose of this study. Obturated teeth were immersed in 2.5% methylene blue for 48hrs. at $37^{\circ}C$ incubator and split. The apical sealing ability was evaluated by measuring the degree of dye penetration into the canal. The results were as follows: 1. All group showed varying depth of dye penetration. 2. There were no significant difference among Group I (lateral condensation), Group II (ULTRAFIL with sealer) & Group IV (ENDOTEC with sealer) (P>0.05). 3. There were less dye penetration when used in conjunction with sealer (P<0.001).

• Restorative Dentistry and Endodontics
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• v.16 no.1
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• pp.181-189
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• 1991

The purpose of this study was to evaluate the effect of apical seal produced by ultrasonic instrumentation. 120 extracted, permanent single rooted teeth were randomly divided into 6 groups of 20 teeth and root canals were enlarged & obturated according to Table I. After canal obturation, the obturated teeth were immersed in 2.5 % Methylene blue for 72 hrs. at $37^{\circ}C$ incubator and longitudinally sectioned. The apical sealing ability was evaluated by measuring the degree of dye penetration into the canal. The results were as follows: 1. All groups showed varying depth of dye penetration. 2. There were no significant differences between Group I and N, Group II and V, Group III and VI. (P>0.05) 3. Regardless of obturation method, there were no significant differences between hand instrumented group and ultrasonic instrumented group.(P>0.05).

• Restorative Dentistry and Endodontics
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• v.20 no.2
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• pp.671-684
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• 1995

The purpose of this study was to compare the apical sealing ability, overfilling and obturation of lateral canals using two gutta-percha techniques: Thermafil obturators and cold lateral condensation. Eighty numbered epoxide blocks with one major and five lateral canals were divided into four experimental groups and obturated according to experimental groups. Four experimental groups were as follows: Group 1 : Filling with Thermafil plastic obturators and sealer(ThermaSeal) Group 2 : Filling with Thermafil plastic obturators only, without sealer(ThermaSeal) Group 3 : Fillng using lateral condensation with sealer(AH-26) Group 4 : Fillng using lateral condensation without sealer(AH-26) All the blocks were stored in 100% relative humidor at room temperature for 7 days. Each block was placed in centrifuge tube filled with India ink, and then centrifuged for 20 minutes at 3,000 rpm. Apical leakage was measured from the apical foramen to the most coronal level of dye penetration in millimeter under a stereoscope. The length of gutta-percha and sealer in each of the lateral canals was measured, too. The presence or absence of overfilling of gutta-percha and sealer was recorded. The data was analyzed by one-way ANOVA. The obtained results were as follows: l. Apical dye leakage was almost: not occurred in Group Willed with Thermafil and sealer) and Group 3(filled using lateral condensation with sealer), and there was no significant difference in linear leakage between two groups(p>0.01). 2. In both Thermafil and lateral condensation groups, linear leakage of Group I, 3(filled with sealer) was less than that of Group 2, 4(filled without sealer), and there was no significant difference in linear leakage between Group 1, 2, 3(p> 0.01). 3. Overfilling during obturation of Group 1, 2(filled with Thermafil) was more than Group 3, 4(filled using lateral condensation), and there was no significant difference between groups(p> 0.05). 4. Groups filled with Thermafil had significantly more gutta-percha than groups filled using lateral condensation in all lateral canals(p <0.01), the total length of gutta-percha and sealer found in all lateral canals were similar in Group 1 and Group 3.

• Restorative Dentistry and Endodontics
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• v.20 no.2
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• pp.610-626
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• 1995

Perforations especially in the furcations during endodontic treatment have notably detrimental effect on prognosis. The purpose of this study was to compare radiographically and histologically the sealing ability and the tissue responses of amalgam, Ketac-Silver, IRM, Vitapex, and mineral trioxide aggregate(MTA) used to repair furcation perforations. Thirty two experimental furcation perforations were created in the mandibular premolars of 6 mongrel dogs and immediately repaired with experimental materials. The animals were sacrificed after 16 weeks and radiographic and histopathologic results were evaluated. The following conclusions were drawn within the limits of the experimental results; 1. All materials tested in this experiment revealed a certain degree of extrusion into the periodontal space. 2. Both amalgam and Ketac-Silver showed the greatest degree of inflammation and bone resorption(p<0.0001). There was no significant difference between the amalgam and Ketac-Silver groups. 3. Both IRM and Vitapex showed a markedly milder degree of inflammatin and less bone resorption than amalgam or ketac-siver(p<0.00005). both IRM and vitapex showed the same respone. 4. MTA showed the least degree of Inflammation and bone resorption(p<0.05). The results of this experiment indicate that among the different materials tested, MTA appeared to be the best material for sealing furcation perforations, although the radiographic and histopathologic differences between the MTA and Vitapex groups were not statistically significant. But further studies with a larger sample are needed to have the exact conclusions.

• Restorative Dentistry and Endodontics
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• v.46 no.2
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• pp.30.1-30.13
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• 2021

Objectives: This study was conducted to compare the microleakage and characteristics of the resin-tooth tissue interface between self-etch and etch-and-rinse adhesive systems after 48 hours and 3 months. Materials and Methods: 40 extracted premolar teeth were randomly divided into 2 groups: 1-step self-etch adhesive system - Optibond^TM All-In-One, and 2-step etch-and-rinse adhesive system - Adper^TM Single Bond 2. Both groups were subjected to 500 thermocycles (5℃-55℃) before scanning electron microscope (SEM) analysis or microleakage trial at 48-hour and 3-month time periods. Results: SEM images showed the hybrid layer thickness, diameter, and length of resin tags of the self-etch adhesive (0.42 ± 0.14 ㎛; 1.49 ± 0.45 ㎛; 16.35 ± 14.26 ㎛) were smaller than those of the etch-and-rinse adhesive (4.39 ± 1.52 ㎛; 3.49 ± 1 ㎛; 52.81 ± 35.81 ㎛). In dentin, the microleakage scores of the 2 adhesives were not different in both time periods (48 hours/3 months). However, the microleakage score of etch-and-rinse adhesive increased significantly after 3 months (0.8 ± 0.63 and 1.9 ± 0.88, p < 0.05). Conclusions: The self-etch adhesive exhibited better long-term sealing ability in dentin when compared to that of the etch-and-rinse adhesive. The greater hybrid layer thickness and dimensions of resin tags did not guarantee reliable, long-lasting sealing in the bonding area.

• Restorative Dentistry and Endodontics
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• v.46 no.1
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• pp.3.1-3.14
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• 2021

Objectives: This study aimed to evaluate the interface between a calcium silicate cement (CSC), Biodentine and dental adhesives in terms of sealing ability. Materials and Methods: Microleakage test: 160 standardized class II cavities were prepared on 80 extracted human molars. The cavities were filled with Biodentine and then divided into 2 experimental groups according to the time of restoration: composite resin obturation 15 minutes after Biodentine handling (D0); restoration after 7 days (D7). Each group was then divided into 8 subgroups (n = 5) according to the adhesive system used: etch-and-rinse adhesive (Prime & Bond); self-etch adhesive 2 steps (Optibond XTR and Clearfil SE Bond); self-etch adhesive 1 step (Xeno III, G-aenial Bond, and Clearfil Tri-S Bond); and universal used as etch-and-rinse or self-etch (ScotchBond Universal ER or SE). After thermocycling, the teeth were immersed in a silver nitrate solution, stained, longitudinally sectioned, and the Biodentine/adhesive percolation was quantified. Scanning electron microscopic observations: Biodentine/adhesive interfaces were observed. Results: A tendency towards less microleakage was observed when Biodentine was etched (2.47%) and when restorations were done without delay (D0: 4.31%, D7: 6.78%), but this was not significant. The adhesives containing 10-methacryloyloxydecyl dihydrogen phosphate monomer showed the most stable results at both times studied. All Biodentine/adhesive interfaces were homogeneous and regular. Conclusions: The good sealing of the CSC/adhesive interface is not a function of the system adhesive family used or the cement maturation before restoration. Biodentine can be used as a dentine substitute.

• Restorative Dentistry and Endodontics
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• v.49 no.2
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• pp.20.1-20.13
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• 2024

Objectives: This study investigated the nanoleakage of root canal obturations using calcium silicate-based sealer according to different drying methods. Materials and Methods: Fifty-two extracted mandibular premolars with a single root canal and straight root were selected for this study. After canal preparation with a nickel-titanium rotary file system, the specimens were randomly divided into 4 groups according to canal drying methods (1: complete drying, 2: blot drying/distilled water, 3: blot drying/NaOCl, 4: aspiration only). The root canals were obturated using a single-cone filling technique with a calcium silicate-based sealer. Nanoleakage was evaluated using a nanoflow device after 24 hours, 1 week, and 1 month. Data were collected twice per second at the nanoscale and measured in nanoliters per second. Data were statistically analyzed using the Kruskal-Wallis and Mann-Whitney U-tests (p < 0.05). Results: The mean flow rate measured after 24 hours showed the highest value among the time periods in all groups. However, the difference in the flow rate between 1 week and 1 month was not significant. The mean flow rate of the complete drying group was the highest at all time points. After 1 month, the mean flow rate in the blot drying group and the aspiration group was not significantly different. Conclusions: Within the limitations of this study, the canal drying method had a significant effect on leakage and sealing ability in root canal obturations using a calcium silicate-based sealer. Thus, a proper drying procedure is critical in endodontic treatment.

• Restorative Dentistry and Endodontics
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• v.15 no.2
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• pp.46-57
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• 1990

The purpose of this study was to spectrophotometrically investigate the sealing effect of the ultrasonic canal obturation with softened gutta-percha utilizing an endosonic plugger by means of ultrasonic vibrations and heat. The 120 extracted human central and lateral incisors with single root were randomly selected, and the root canals were instrumented up to size #60 file by conventional method. The prepared canals were obtruated with gutta-percha by lateral condensation method, McSpadden technique and ultrasonic condensation method, with or without sealer. All specimens were immersed in 2% methylene blue in an incubator at $37^{\circ}C$ for 10 days. The teeth were then dissolved in 5ml of 60% nitric acid solution and the dye present within the root canal system was returned to solution. The leakage of dye was quantitatively measured via spectrophotometric method. The obtained data statistically evaluated usint two-way ANOVA and Student's t-test. The results were as follows : No statistically significant difference in leakage was observed between the lateral condensation method and ultrasonic condensation method, with and without sealer. When sealer was used or not, McSpadden technique showed significantly greater leakage than lateral or ultrasonic condensation method. Statistical analysis of the data indicated that the canals obturated in conjunction with sealer demonstrated less dye leakage than the canals obturated without sealer(p<0.01), except McSpadden technique. The ultrasonic condensation method appeared comparable sealing ability to the lateral condensation method.

• Journal of Microbiology and Biotechnology
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• v.22 no.11
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• pp.1568-1574
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• 2012

Microbiological calcium carbonate precipitation (MCCP) has been investigated for its ability to improve the durability of cement mortar. However, very few strains have been applied to crack remediation and strengthening of cementitious materials. In this study, we report the biodeposition of Bacillus subtilis 168 and its ability to enhance the durability of cement material. B. subtilis 168 was applied to the surface of cement specimens. The results showed a new layer of deposited organic-inorganic composites on the surface of the cement paste. In addition, the water permeability of the cement paste treated with B. subtilis 168 was lower than that of non-treated specimens. Furthermore, artificial cracks in the cement paste were completely remediated by the biodeposition of B. subtilis 168. The compressive strength of cement mortar treated with B. subtilis 168 increased by about 19.5% when compared with samples completed with only B4 medium. Taken together, these findings suggest that the biodeposition of B. subtilis 168 could be used as a sealing and coating agent to improve the strength and water resistance of concrete. This is the first paper to report the application of Bacillus subtilis 168 for its ability to improve the durability of cement mortar through calcium carbonate precipitation.