• The Journal of the Korean dental association
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• v.20 no.12 s.163
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• pp.1025-1028
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• 1982

1) The authors have had a case of crown fractured upper central incisor with open apex and non vital pulp. 2) The patient was 8 years old female. 3) Apical closure has been induced with the use of calcium hydroxide and gutta percha cone. 4) At nine month after filling with calcium hydroxide and gutta percha cone, apical closure was observed by radiograph. 5) Root canal was permanently filled gutta percha cone and zinc oxide eugenol by the lateral condensation technique.

• Proceedings of the KACD Conference
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• 2001.11a
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• pp.592.2-592
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• 2001

The purpose of this study was to evaluate the efficiency of the four obturation techniques. In this study, eighty teeth were instrumented and randomly divided into 4 groups of 20 teeth each, according to the obturation techniques Group A was used with Microseal. in Group B, Thermafil. in Group C, continuous wave techniques, in Group D cold lateral condensation methods were used. After obturation, the teeth were taken a digital radiograph in mesiodistal and buccolingual directions to study the quality of the obturation.(omitted)

• Restorative Dentistry and Endodontics
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• v.27 no.4
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• pp.411-420
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• 2002

The aim of this study is to compare the adaptability of thermoplasticized injectable gutta-percha technique to the canal walls in ribbon-shaped canals. Thirty resin models simulated ribbon-shape canals were instrumented to #40 using .06 taper Profile systems. Three groups of each 10 resin models were obturated by the lateral condensation technique(LC) and the two thermoplasticized injectable gutta-percha technique; Ultrafil Endoset+Obtura II(EO) and Ultrafil Firmset(UF), respectively. After resin model were kept at room temperature for 4 days, they were resected horizontally with micro-tome at 1, 2, 3, 4 and 5mm levels from apex. At each levels. image of resected surface were taken using CCD camera under a stereomicroscope at $\times$40 magnification and stored. Ratio of the area of gutta-percha was obtained by calculating area of gutta-percha cone to the total area of canal using digitized image-ana-Iyzing program. The data were collected then analyzed statistically using One-way ANOVA. The results were as follows. 1 At 1mm levels, there was no statistically significant difference in the mean ratio of gutta-percha among the groups. 2. At 2mm level, EO showed the highest mean ratio of gutta-percha (p<0.05) and there was no significant difference between LC and UF. 3. At 3, 4, 5mm levels, EO and UF had significantly greater mean ratio of gutta-percha than LC(p<0.05) and there was no significant difference between EO and UF. In conclusion, the thermoplasticized injectable gutta-percha techniques demonstrated relatively favorable adaptability to canal walls than lateral condensation technique in ribbon-shaped canals except for 1mm level.

• Imaging Science in Dentistry
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• v.42 no.3
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• pp.129-137
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• 2012

Purpose: To compare different radiographic methods for assessing endodontically treated teeth. Materials and Methods: Root canal treatments were applied in 120 extracted mandibular teeth, which were divided into four groups: (1) ideal root canal treatment (60 teeth), (2) insufficient lateral condensation (20 teeth), (3) root canals filled short of the apex (20 teeth), (4) overfilled root canal treatment (20 teeth). The teeth were imaged using intraoral film, panoramic film, digital intraoral systems (CCD and PSP), CCD obtained with portable X-ray source, digital panoramic, and CBCT images obtained at 0.3 $mm^3$ and 0.2 $mm^3$ voxel size. Images were evaluated separately by three observers, twice. Kappa coefficients were calculated. The percentage of correct readings obtained from each modality was calculated and compared using a t-test (p<0.05). Results: The intra-observer kappa for each observer ranged between 0.327 and 0.849. The inter-observer kappa for each observer for both readings ranged between 0.312 and 0.749. For the ideal root canal treatment group, CBCT with 0.2 $mm^3$ voxel images revealed the best results. For insufficient lateral condensation, the best readings were found with periapical film followed by CCD and PSP. The assessment of teeth with root canals filled short of the apex showed the highest percentage of correct readings by CBCT and CCD. For the overfilled canal treatment group, PSP images and conventional periapical film radiographs had the best scores. Conclusion: CBCT was found to be successful in the assessment of teeth with ideal root canal treatment and teeth with canals filled short of the apex.

• Restorative Dentistry and Endodontics
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• v.13 no.1
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• pp.151-158
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• 1988

The purpose of this study was to evaluate the effect of canal filling methods and post-space preparation time on the apical seal of endodontically treated teeth. Seventy-six single-rooted human teeth were divided into 6 groups and each tooth was obturated and prepared post-space according to the purpose of this study. After all specimens were immersed in Indian ink, decalcified and cleared, the degree of dye penetration into the root canals observed by magnifying glass (X20) and measured by caliper. The results were as follows: 1. In the thermatic condensation, no significant difference in ink penetration occured when the post-spaces were created immediately after obturation or when they were made a week later. 2. In the lateral condensation, no significant difference in ink penetration existed between teeth whose post-space were prepared immediately or delayed. 3. In comparison of experimental groups and control groups, no significant difference showed when the groups were obturated with McSpadden compactor but when the teeth were laterally condensed, the experimental groups showed less ink penetration than controls. 4. Thermatic condensed teeth with McSpadden compactor were less ink penetration thn laterally condensed teeth.

• Restorative Dentistry and Endodontics
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• v.23 no.2
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• pp.682-689
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• 1998

The purpose of this study was to evaluate the sealing ability of the Microseal$^{(R)}$, which was new obturation system made by Tycom company, U.S.A. Forty-five extracted single-rooted human teeth were resected at cemento-enamel junction and divided three groups. All canals were prepared using Profile system, and then each group was obturated by lateral condensation technique (group 1), vertical condensation technique (group 2) and Microseal$^{(R)}$ condensation technique (group 3) with root canal sealer. 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 resected horizontally at 1 mm (level I), 2 mm (level II), 3 mm (level III) from the anatomical root apex using low speed microtome and examined with Image analyzer (IBASR, Zeiss co., Germany.) at ${\times}25$ magnification. The gab 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 expressed percentage by calculating the ratio of the area of the resin to the total area of the canal and was analyzed statistically (one-way ANOVA). The results were as follows; 1. The mean ratio of leakage (%) was 6.46% at group 1, 3.06% at group 2, 11.27% at group 3. 2. When evaluating the ratio of leakage at the three levels, there was level I> level II> level III in all groups. Especially, the difference between level I and level III was statistically significant (p<0.05). 3. When evaluating the ratio of leakage at the three groups, there was group 3> group 1> group 2 at all levels. Especially the difference between group 2 and group 3 was statistically significant (p<0.05).

• Restorative Dentistry and Endodontics
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• v.41 no.1
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• pp.22-28
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• 2016

Objectives: The goal of this study was to compare the density of gutta-percha root fillings obturated with the following techniques: cold lateral (CL) compaction, ultrasonic lateral (UL) compaction, and warm vertical (WV) compaction. Materials and Methods: Thirty-three extracted mandibular first molars, with two separate mesial canals in each, were selected. After instrumentation, the canals were stratified into three groups based on canal length and curvature, and underwent obturation with one of the techniques. No sealer was used in order to avoid masking any voids. The teeth were imaged pre- and post-obturation using micro-computed tomography. The reconstructed three-dimensional images were analyzed volumetrically to determine the amount of gutta-percha present in every 2 mm segment of the canal. P values < 0.05 were considered to indicate statistical significance. Results: The overall mean volume fraction of gutta-percha was $68.51{\pm}6.75%$ for CL, $86.56{\pm}5.00%$ for UL, and $88.91{\pm}5.16%$ for WV. Significant differences were found between CL and UL and between CL and WV (p < 0.05), but not between UL and WV (p = 0.526). The gutta-percha density of the roots treated with WV and UL increased towards the coronal aspect, but this trend was not noted in the CL group. Conclusions: WV compaction and UL compaction produced a significantly denser gutta-percha root filling than CL compaction. The density of gutta-percha was observed to increase towards the coronal aspect when the former two techniques were used.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2005.04a
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• pp.105-112
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• 2005

Recently, Various structural systems for skyscrapers are studied as structures are more higher. The mega frame system of all, which is the structural system developed recently, are considered as a suitable structural system for skyscrapers. This structural system has sufficient stiffness for the lateral forces with mega-columns which consist of many columns and mega-girders which consist of girders with large stiffness or trusses. But there is no efficient analysis method and a design method for it. Therefore, an efficient analytical model, which has only DOFs selected by the user using the matrix condensation technique, is proposed in this study to obtain accurate results in significantly reduced computational time.

• The Journal of the Korean dental association
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• v.56 no.10
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• pp.567-571
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• 2018

Obturation is a important procedure of root canal treatment. Canal filling should be both provide a hermetic seal for the root canal system and eliminate leakage channel from the oral cavity. Gutta-percha have been the standard material of choice for root canal obturation. Canal filling has been aimed at maximizing the amount of gutta-percha and minimizing the amount of sealer. However recently, single cone technique has been introduced that include calcium silicate-based sealer and single gutta-percha cone. It is important to select an obturation technique that offers consistency and is easy to use. From the standpoint of appropriate technology, the single cone technique is thought to be useful for general dentist.

• Proceedings of the KACD Conference
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• 2001.11a
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• pp.587.1-587
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• 2001

The aim of this study is to compare the adaptability of thermoplasticized injectable gutta-percha technique to the canal walls in ribbon-shaped canals. Thirty resin models simulated ribbon-shaped canals were instrumented to ＃40 using. 06 taper Profile systems. Three groups of 10 resin models were obturated by the lateral condensation technique(LC) and the two thermoplasticized injectable gutta-percha technique; Ultrafil Endoset＋Obtura II(EO) and Ultrafil Firmset(UF), respectively.(omitted)