• Restorative Dentistry and Endodontics
• /
• v.36 no.3
• /
• pp.238-242
• /
• 2011

Objectives: Palatogingival groove is a developmental anomaly that starts near the cingulum of the tooth and runs down the cementoenamel junction in apical direction, terminating at various depths along the roots. While frequently associated with periodontal pockets and bone loss, pulpal necrosis of these teeth may precipitate a combined endodontic-periodontal lesion. This case presents a case of a lateral incisor anatomically complicated with palatogingival groove. Methods: Two patients with lesion associated with the palatogingival groove were chosen for this report. Palatogingival grooves were treated with different restoration materials with endodontic treatment. Conclusions: Maxillary lateral incisor with a palatogingival groove may occur the periodontal disease with pulpal involvement. Elimination of groove may facilitate the periodontal re-attachment and prevent the recurrence.

• Journal of the Korean Society of Visualization
• /
• v.14 no.1
• /
• pp.40-45
• /
• 2016

Elimination of the smear layer and bacteria in the root canal is the most important in the endodontic treatment, and various irrigation devices have been developed. Nevertheless, it is hard to eliminate the smear layer and bacteria completely. In this paper, a micro bubble irrigation system has been developed for the root canal cleaning of tooth. Micro bubbles are generated when pressurized fluids passing through a porous material inside a hand-piece nozzle, and the bubbly flows excited by ultrasonic vibration are observed using a high-speed camera and a microscope. The results show that the diameter and number of bubbles increases with the applied pressure, and there found an optimum excitation frequency in order to minimize the bubble size. From in-vitro tests, it is also verified that the developed bubble irrigation system has the ability of antibacterial and infection removal. Thus, this biocompatible system would be well suited for root canal cleaning.

• Restorative Dentistry and Endodontics
• /
• v.32 no.6
• /
• pp.491-497
• /
• 2007

The purpose of this study was to compare apical sealing ability of continuous wave canal filling technique according to various heat source plugging depths. Eighty one extracted human premolars with straight root were cleaned and shaped to size 35 using .06 taper rotary NiTi file. After cleansing and shaping, the teeth were divided into 5 groups following the heat source probing depths from the apex; 3, 4, 5, 6 and 7 mm. All specimens were filled using E&Q plus with #35/.06 tapered gutta-percha cone. The positive control teeth were not filled. All teeth were coated with nail varnish except the apical 1 mm around the apical foramen. Negative control teeth were completely sealed include the apical foramen. All specimens were immersed in 1% methylene blue solution for 72 hours. Then the specimens were sectioned horizontally at 1, 2 and 3 mm from the root apex. Each sectioned surface was photographed using a digital camera attached to the stereomicroscope at $12.5{\times}2.5$ fold magnification. All points at 1, 2 and 3 mm were summed as final score of one specimen. Statistical analysis of the collected data was performed. Under the condition of this study. there was no significant difference between the heat source plugging depths of 3, 4, 5, 6 and 7 mm in apical sealing ability. All of apical heat source plugging depth from 3 to 7 mm including Buchanan's protocol -from 5 to 7 mm- seems to be acceptable in clinical application.

• Restorative Dentistry and Endodontics
• /
• v.37 no.1
• /
• pp.24-28
• /
• 2012

Objectives: The aim of this study was to test the hypothesis, that the effectiveness of irrigation in removing smear layer in the apical third of root canal system is dependent on the depth of placement of the irrigation needle into the root canal and the enlargement size of the canal. Materials and Methods: Eighty sound human lower incisors were divided into eight groups according to the enlargement size (#25, #30, #35 and #40) and the needle penetration depth (3 mm from working length, WL-3 mm and 9 mm from working length, WL-9 mm). Each canal was enlarged to working length with Profile.06 Rotary Ni-Ti files and irrigated with 5.25% NaOCl. Then, each canal received a final irrigation with 3 mL of 3% EDTA for 4 min, followed by 5 mL of 5.25% NaOCl at different level (WL-3 mm and WL-9 mm) from working length. Each specimen was prepared for the scanning electron microscope (SEM). Photographs of the 3mm area from the apical constriction of each canal with a magnification of ${\times}250$, ${\times}500$, ${\times}1,000$, ${\times}2,500$ were taken for the final evaluation. Results: Removal of smear layer in WL-3 mm group showed a significantly different effect when the canal was enlarged to larger than #30. There was a significant difference in removing apical smear layer between the needle penetration depth of WL-3 mm and WL-9 mm. Conclusions: Removal of smear layer from the apical portion of root canals was effectively accomplished with apical instrumentation to #35/40 06 taper file and 3 mm needle penetration from the working length.

• Restorative Dentistry and Endodontics
• /
• v.34 no.6
• /
• pp.500-507
• /
• 2009

The purpose of this study is to compare the antibacterial effect of $Listerine^{(R)}$ on two microorganisms (P. gingivalis and E. faecalis) with various root canal irrigants (NaOCl, CHX, EDTA) and to identify possibility of using $Listerine^{(R)}$ as a root canal irrigant. Porphyromonas gingivalis ATCC 3327 and Enterococcus faecalis ATCC 29212 were used in this experiment. For the test irrigants, 0.5%, 1%, 2.5%, 5.25% NaOCl, 0.1%, 0.2%, 1%, 2% CHX, 0.5M EDTA (18.6% EDTA) and $Listerine^{(R)}$ were prepared. Distiled water was used as control. Two methods-1) Comparison of turbidity in broth and 2) Agar diffusion test-were used to determine the extent of antibacterial effect of $Listerine^{(R)}$ and to compare it with that of NaOCl, CHX, and EDTA. All solutions tested were effective against two bacterial strains compared with control (p < 0.001). Any concentration of NaOCl, CHX, and EDTA showed similarly high effectiveness against all bacterial strains. In all experiment, $Listerine^{(R)}$ showed significantly low antibacterial effect compared with the other root canal irrigants (p < 0.05). In conclusion, the results reflect remarkably low antibacterial effect of $Listerine^{(R)}$ as compared with root canal irrigants in general so it is not suitable for the root canal irrigant.

• Restorative Dentistry and Endodontics
• /
• v.27 no.6
• /
• pp.577-586
• /
• 2002

The purpose of this in vitro study was to compare the effects of root canal cleanness following two Ni-Ti rotary instruments with different rake angle. Thirty-six sound, extracted human premolars with single root were randomly divided into three groups. The used rotary instruments were HEROShaper (Group 1, Micro-Mega, Besancon, France, n=12) and ProFile (Group 2, Maillefer, Ballaigues, Switzerland, n=12). Control group (n=12) was only extirpated with barbed broach (Mani, Matsutani Seisakusho Co., Japan) Group 1 & 2 teeth were prepared to a #40/.04 taper at the apex followed by 1 mm using crown-down technique. After canal preparation and frequent irrigation with 5.25% sodium hypochlorite, the roots split longitudinally into a bucco-lingual direction. Root halves were cross-sectioned in apical third portion again. All root specimens were processed for SEM investigation and photographed. Separate evaluations by one endodontist were undertaken for smear layer on prepared walls with a five score-index for each using reference photograph in root halves. The penetration depth of smear layer into dentinal tubules was also estimated in the other halves. Following results were obtained: 1. Smear layer was observed on all the prepared walls with two experimental groups except control group. 2. Smear layer characteristics in two experimental groups; 1) HEROShaper group showed snowy, dusty appearance and were shown open dentinal tubuli on the prepared walls of almost specimens, and the thickness of smear layer covering onto dentinal surfaces was within 1-2 ${\mu}m$ in a few specimens. 2) ProFile group showed shiny, burnished appearance and complete root canal wall covered by a homogenous smear layer with no open dentinal tubuli in all specimens. The penetration of smear layer into dentinal tubules was found in all specimens and the thickness was at 2-4 ${\mu}m$ in all specimens. These results demonstrated that a completely clean root canal could not be achieved regardless of positive or negative rake angle, which is in accordance with the majority of previous studies on root canal cleanliness In conclusion, through irrigation with antibacterial solutions or chelating agents is recommended to remove the smear layer on prepared canal wall in spite of Ni-Ti instrumentation.

• Restorative Dentistry and Endodontics
• /
• v.31 no.5
• /
• pp.378-389
• /
• 2006

The purpose of this study was to compare the sealing ability of root canal obturation with or without the treatment of smear layer. Eighty extracted human teeth with one canal were selected Instrumentation was performed with crown-down technique. After instrumentation, root canals of the NaOCl group and NaOCl-6 group were irrigated with 3% NaOCl. EDTA group and EDTA-6 group were irrigated with 17% EDTA. Then all teeth were obturated using continuous wane obturation technique NaOCl group and EDTA group were immersed in methylene blue solution for 84hours. NaOCl-6 group and EDTA-6 group were immersed in methylene blue solution for 6months. The teeth were sectioned at 1.5 mn (Level 1), 3.0 mm (Level 2) and 4.5 mm (Level 3) from the root apex. The length of dye-penetrated inter-face and the circumferential length of canal at each level were measured using Sigma-Scan Pro 5.0. 1. The mean leakage ratio was decreased cervically. 2. NaOCl group showed higher mean leakage ratio than EDTA group at each level. But there was significant difference at level 1 only (p < 0.05). 3. NaOCl-6 group showed higher mean leakage ratio than EDTA-6 group at each level. But there was significant difference at level 1 only (p < 0.05). 4. NaOCl-6 group showed higher mean leakage ratio than NaOCl group at each level. But there was significant difference at level 1 only (p < 0.05). 5. EDTA-6 group showed higher mean leakage ratio than EDTA group at each level. But there was no significant difference. 6. In NaOCl group and NaOCl-6 group, scanning electron micrographs of tooth sections generally covered with smear layer. In EDTA group and EDTA-6 group, tooth sections showing the penetration of sealers to opened dentinal tubules. The results suggest that removal of smear layer was effective to reduce the apical microleakage of the root canal.