• The Journal of the Korean dental association
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• v.21 no.6 s.169
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• pp.467-472
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• 1983

Thirty seven human maxillary third mooars were injected with china ink, decalcified, cleared, and used in vitro study to determine the number of root canals the frequency and location of lateral canals, canals per root, and frequency of apical deltas. The results were as follows: 1. Less than half of the examined teeth showed 3 roots and 3 canals. 2. The mesiobuccal root was ound to contain a single primary canal in 65.4% of the teeth examined and two canals in 34.6% of the teeth studed. 3. In mesiobuccal roots with two canals, the separated apical foramen appeared 30.8% of the specimen concerned, but no common apical foramen appeared. 4. Of the 106 canals studied, 46.2% of the canals were found to contain lateral canals and these ramifications were mainly located in the apical third of the root.

• The Journal of the Korean dental association
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• v.15 no.11
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• pp.753-756
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• 1977

Eighty-two maxillary canine were injected with china ink, decalcified, cleared and used in a study, in vitro, to determine the number of root canals, the frequency and location of lateral canals, the location of apical foramens, and the curvature of root canals. The results were as follows; 1.All of the maxillary canines showed the single canals. 2. Of the 82 canals studied, 20.7% of the canals were found to have lateral canals and most ramification of them were located in the apical third of the root. 3. In the case of the curvature, the mesial curvature of the canals (40.3%) usually showed more than the distal curvature of them (13.4%) 4. 41.2% of the apical foramen were located directly on the root apex and 58.5% of them laterally.

• Restorative Dentistry and Endodontics
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• v.3 no.1
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• pp.12-16
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• 1977

One hundred human maxillary first molars were injected with china ink, decalcified, cleared, and used in vitro study to determine the number of root canals, the frequency and location of lateral canals, canals per root, and frequency of apical deltas. The results were as follows; 1. The mesiobuccal root was found to contain a single primary canal in 53% of the teeth studied and two canals in 47 % of the teeth studied. 2. In mesiobuccal roots with two canals, the seperated apical foramen appeared 32% of the specimens and the common apical foramen 15% of the specimens. 3. Of the 347 canals studied, 26.9% of the canals were found to contain lateral canals and these ramifications were mainly located in the apical third of the root.

• Restorative Dentistry and Endodontics
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• v.6 no.1
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• pp.83-86
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• 1980

Fifty human maxillary second molars were injected with china ink, decalcified, cleared, and used in vitro study to determine the number of root canals, the frequency and location of lateral canals, canals per root, and frequency of apical deltas. The results were as follows. 1. The mesiobuccal root was found to contain a single primary canal in 62% of the teeth studied and two canals in 38% of the teeth studied. 2. In mesiobuccal roots with two canals, the seperated apical foramen appeared 24% of the specimens and the common apical foramen 14% of the specimens. 3. Of the 169 canals studied, 23.1% of the canals were found to contain lateral canals and these ramifications were mainly located in the apical third of the root.

• Restorative Dentistry and Endodontics
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• v.43 no.1
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• pp.10.1-10.8
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• 2018

Objectives: To examine the surface topography of intact WaveOne (WO; Dentsply Sirona Endodontics) and WaveOne Gold (WOG; Dentsply Sirona Endodontics) nickel-titanium rotary files and to evaluate the presence of alterations to the surface topography after root canal preparations of severely curved root canals in molar teeth. Materials and Methods: Forty-eight severely curved canals of extracted molar teeth were divided into 2 groups (n = 24/each group). In group 1, the canals were prepared using WO and in group 2, the canals were prepared using WOG files. After the preparation of 3 root canals, instruments were subjected to atomic force microscopy analysis. Average roughness and root mean square values were chosen to investigate the surface features of endodontic files. The data was analyzed using one-way analysis of variance and post hoc Tamhane's tests at 5% significant level. Results: The surface roughness values of WO and WOG files significantly changed after use in root canals (p < 0.05). The used WOG files exhibited higher surface roughness change when compared with the used WO files (p < 0.05). Conclusions: Using WO and WOG Primary files in 3 root canals affected the surface topography of the files. After being used in root canals, the WOG files showed a higher level of surface porosity value than the WO files.

• Imaging Science in Dentistry
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• v.36 no.3
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• pp.137-143
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• 2006

Purpose : To evaluate location, distribution, diameter, and length of the nutrient canals on mandibular anterior region using a cone beam computed tomography (CBCT). Materials and Methods : Mandibular CBCT was performed on 33 adults (18 males and 15 females) with no history of systemic disease, and any other dental surgery history Location, distribution, diameter, and length of the nutrient canals on mandibular anterior region were radiographically evaluated. A statistical comparison was done by SPSS. Results : In the location and distribution of nutrient canals, they were found in 6.8% at labial portion above root apex, in 93.28% at lingual portion above root apex in 46.2% at labial portion below root apex, and in 53.6% at lingual portion below root apex. Nutrient canals at lingual portion above root apex were most frequently observed between central and lateral incisors, and those at labial and lingual portion below root apex were most frequently observed between central incisors. The mean diameters of nutrient canals were 0.54 mm at labial portion above root apex, 0.61 mm at lingual portion above root apex, 0.66 mm at labial portion below root apex, and 0.76 mm at lingual portion below root apex. The mean lengths of nutrient canals were 2.63 mm at labial portion above root apex, 3.74 mm at lingual portion above root apex, 4.51 mm at labial portion below root apex, and 6.77 mm at lingual portion below root apex. Conclusion : CBCT is useful device to evaluate the anatomical structure of nutrient canals on mandibular anterior region.

• The Journal of the Korean dental association
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• v.16 no.12 s.115
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• pp.929-933
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• 1978

Sixty six mandibular incisor were injected with China ink, decalcified, cleared and used to study the number of root canals, the frequency and location of lateral canals, the location of apical foramens, the frequency of apical deltas, and the curvature of root canals. The results were as follows: 1. Most of the teeth demonstrated single canal, but 19.7% of the teeth were found to have bifurcated canals. 2. 12% of the teeth were found to have lateral canals and these ramifications were located in the apical third of the root. 3. 25 apical foramens were located directly on the root apex and 41 foramens laterally. 4. 43 canals showed straight, 7 canals distal curvature, 7 labial curvature, 3 mesial curvature.

• Restorative Dentistry and Endodontics
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• v.41 no.1
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• pp.68-73
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• 2016

This case report describes a unique C-shaped mandibular second premolar with four canals and three apical foramina and its endodontic management with the aid of cone-beam computer tomography (CBCT). C-shaped root canal morphology with four canals was identified under a dental operating microscope. A CBCT scan was taken to evaluate the aberrant root canal anatomy and devise a better instrumentation strategy based on the anatomy. All canals were instrumented to have a 0.05 taper using 1.0 mm step-back filing with appropriate apical sizes determined from the CBCT scan images and filled using a warm vertical compaction technique. A C-shaped mandibular second premolar with multiple canals is an anatomically rare case for clinicians, yet its endodontic treatment may require a careful instrumentation strategy due to the difficulty in disinfecting the canals in the thin root area without compromising the root structure.

• The Journal of the Korean dental association
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• v.49 no.11
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• pp.660-669
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• 2011

Er: YAG laser irradiation utilizing the newly developed RCLase side-firing spiral tip was used for the cleansing of root canals following their bio-mechanical preparation with ProTaper Ni-Ti files. The distal and palatal roots of 20 freshly extracted molar teeth were instrumented to size F3 with ProTaper files. In the experimental group (10 teeth) the pulp chamber and the root canals were filled with EDTA 17% and the root canals were lased for 30 s using the Er: YAG laser irradiation at 600 mJ per pulse and a frequency of 12 Hz. In the control group (10 teeth) the root canals were not lased. Scanning electron microscope analysis showed clean wall surfaces of the lased root canals with open dentinal tubules, free of smear layer and debris. In the scanning electron microscope photographs of the walls of the non-lased root canals a considerable amount of debris could be detected. It appears that an efficient cleansing of the root canal system can be achieved by using the Er: YAG laser irradiation with the RCLase Side-firing Spiral Tip following bio-mechanical preparation of the root canal with Ni-Ti Taper files.

• Anatomy and Cell Biology
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• v.56 no.2
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• pp.185-190
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• 2023

The root canal morphology undergoes aging-related changes, and relevant quantitative analyses have not yet been reported. We compared the cone beam computed tomography (CBCT) and micro-computed tomography (microCT) scans of extracted mandibular incisors to check the accuracy of morphological measurements. Thereafter, the root canal morphology and aging-related changes in the mandibular incisors of Japanese individuals were assessed using CBCT. Six extracted teeth were fixed in a phantom head and imaged using CBCT and micro-CT. The correlation between the findings of the two imaging modalities was examined. Further, CBCT reconstructed images of the mandibular incisors of 81 individuals were observed. Age-related changes of the root canals were compared between participants aged <30 years and those aged ≥30 years. The CBCT and micro-CT findings regarding the root canals of the extracted teeth coincided in 94.4% of the cases. Mandibular incisors exhibiting two root canals in either cross-section accounted for 9.9% of central incisors and 12.4% of lateral incisors. Mandibular central incisors with two root canals were observed in two (6.3%) individuals aged <30 years and six (12.2%) aged ≥30 years. Mandibular lateral incisors with two root canals were observed in one (3.1%) individual aged <30 years and nine (18.4%) aged ≥30 years. CBCT allows accurate evaluation of complex root canal morphologies and is useful for endodontic preoperative assessment. Mandibular incisors have more frequent occurrence of two root canals with aging.