Three-dimension model of root canal morphology of primary maxillary incisors by micro-computed tomography study

The success of root canal treatment for deciduous teeth depends upon the shape of the root canal, among other factors. Despite this, there are limited reports on the use of high-resolution micro-CT to describe the root canal morphology of primary maxillary incisors. In this study, we aimed to create a three-dimensional (3D) digital model of the root canal morphology of primary maxillary incisors using microcomputed tomography (micro-CT). To provide a reference for the development of restorative posts for the primary maxillary incisors. Primary maxillary central and lateral incisors (n = 10 each) were analysed. Micro-computed tomography was used to conduct 3D analyses of the root canal system of the primary maxillary incisors. The canal volume and surface area of the primary maxillary central incisors were larger than those of the primary maxillary lateral incisors. The structural model index value was significantly lower in central incisors. At the cervical level and the interface between the cervical and middle one-third cross-sectional levels, the root canals of the primary maxillary lateral incisors were significantly rounder. The labio-palatal dimension and the diameters of the central incisors at the four different levels were significantly smaller than the diameter of the mesio-distal dimension. The taper of the central and lateral incisors gradually increased from the apical one-third to the cervical one-third in the labio-palatal dimension. The data obtained from the 3D analysis of maxillary incisors in this study will contribute to the design of root canal posts.

Mandibular incisors with two canals are associated with the presence of the distolingual root in mandibular first molars: a cone-beam computed tomographic study

Background

This study aimed to evaluate the root canal configurations and the association between mandibular first molars and distolingual root (DLR) and mandibular incisors using cone-beam computed tomography (CBCT).

Methods

Mandibular first molars and incisors were evaluated using CBCT images of 150 patients. Mandibular first molars were classified according to the presence or absence of DLR. The curvature of the DLR was evaluated using Schneider’s method in buccolingual and mesiodistal orientations. The angle of the mesiolingual–distolingual–distobuccal canal orifices (ML–DL–DB) was evaluated at the pulpal floor level. The mandibular central and lateral incisors were classified as either single canal or two canals. The association between the root canal system of the mandibular first molar and mandibular incisors was evaluated. Data were analyzed using the Chi-square test, Student’s t-test, and odds ratios from binary logistic regression. The significance level was set at 5%.

Results

The frequency of mandibular first molars with DLR was 27.0% and that of mandibular incisors with two canals was 25.8%. The curvature of the DLR was 37.1° in the buccolingual orientation and 10.4° in the mesiodistal orientation. The angle of ML–DL–DB was 79.0°. The presence of two canal systems in mandibular incisors was associated with the presence of DLR in the mandibular first molar (left central incisors: p = 0.001, odds ratio = 4.25; left lateral incisors: p < 0.001, odds ratio = 3.8; right central incisors: p = 0.003, odds ratio = 3.86; right lateral incisors: p = 0.001, odds ratio = 3.44) but not with the curvature of the DLR or angle of the ML–DL–DB orifice (p > 0.05).

Conclusions

The mandibular first molar showed a high incidence of separate DLRs. It was confirmed that DLR in the mandibular first molar is highly associated with the presence of two-canal system in the mandibular incisors. This association can aid clinicians in successful endodontic treatments.

Micro-CT assessment of radicular pulp calcifications in extracted maxillary first molar teeth

OBJECTIVES

The present study aimed to evaluate the frequency, position, and length of radicular pulp calcifications in three-rooted maxillary first molars using micro-computed tomography.

MATERIALS AND METHODS

Two hundred three-rooted maxillary first molars were scanned at a pixel size of 10 µm and reconstructed using similar parameters. Three-dimensional models of the mesiobuccal (MB1, MB2, MB3), distobuccal (DB), and palatal (P) canals were qualitatively evaluated for discontinuity in the canal path. Transaxial and sagittal cross-sectional images of the roots were further screened, and the complete obliteration of the canal lumen by pulp calcification was identified when the canal had similar radiodensity to the surrounding dentine. Then, the number, position, and length of the calcifications were recorded for each root. Intra-observer agreement was performed using Cohen's kappa test, while one-way ANOVA and Duncan tests compared the lengths of calcifications among the canals, with α = 5%.

RESULTS

Intra-observer agreement was perfect for identification of pulp calcifications (ĸ = 1.0; p = 0.000). MB2 and MB3 canals accounted for the highest percentage frequency of calcifications distributed throughout the canal path. In the MB1, DB, and P canals, they occurred mainly at the apical third. Lengths of calcifications were greater in the MB3 (0.89 ± 0.81 mm) and MB2 (0.82 ± 0.93 mm) canals than in the MB1 (0.39 ± 0.32 mm), DB (0.34 ± 0.22 mm), and P (0.28 ± 0.22 mm) canals (p < 0.05).

CONCLUSION

MB2 and MB3 canals accounted for the highest frequency and length of radicular pulp calcifications. In the MB1, DB, and P canals, calcifications occurred mostly at the apical third, while in the MB2 and MB3, most of calcifications were observed at the orifice level and along the canal path.

CLINICAL RELEVANCE

In maxillary first molars, radicular pulp calcifications are mainly located at the apical third of the MB1, DB, and P canals, while in the MB2 and MB3 canals, most of them are at the orifice level or along the canal path.

CBCT evaluation of root canal morphology and anatomical relationship of root of maxillary second premolar to maxillary sinus in a western Chinese population

BACKGROUND

To evaluate the root anatomy, root canal morphology and the anatomical relationship between the roots and maxillary sinus of maxillary second premolars by CBCT in a western Chinese population.

METHODS

A total of 1118 CBCT scans of the maxillary second premolars were collected from West China Hospital of Stomatology, Sichuan University. Information below were measured on axial, coronal and sagittal sections, recorded and evaluated properly: the number of roots and canals, the morphology of canal system classified by Vertucci standard, the inter-orifice distance of canal orifices, the curvature of each canal and the distance from root tip to maxillary sinus floor.

RESULTS

Among the 1118 teeth, 94.2% (1053) are single-rooted and 55.1% (616) have one canal. Type I (55.1%) is the commonest root canal morphology followed by Type II (31.9%). The mean inter-orifice distance (IOD) for multi-canal teeth ranging from 2.72 ± 0.32 to 3.41 ± 0.11 mm. Of 1622 canals, 38.8% (630) curvature are mesiodistal and 30.9% (501) are straight canals. The distance from root tip to maxillary sinus floor increased with age and the mean distance of single-rooted ones is 2.47 ± 3.45 mm.

CONCLUSIONS

All kinds of canal morphology category can be detected in maxillary second premolars. The IOD might be a predictable factor for root canal morphology. Roots of maxillary second premolars are related to maxillary sinus which should be treated carefully.

Contemporary Cleaning of the Root Canal System

This article provides a contemporary synopsis of effective cleaning of the root canal system, an essential stage of root canal treatment. It provides a clinical update on the current state of knowledge on cleaning of the root canal system, and presents an outline of essential theory and practical tips for achieving effective and safe cleaning of the root canal system.

Mandibular first premolar with five root canals: a case report

Background

Understanding the anatomical morphology of the root canal is key for successful root canal treatment. The aims of this case presentation are to report a unique case of root canal treatment involving five root canals in the mandibular first premolar and to highlight the importance of variation in root canals of mandibular first premolars in clinical practice.

Case presentation

A 25-year-old male with intermittent pain in relation to the lower right posterior teeth over 3 weeks was diagnosed with symptomatic pulpitis in tooth #44. Four root canals were found, including mesiobuccal, distobuccal-1, distobuccal-2, and distolingual roots, and the Mtwo rotary system was used for root canal preparation. The four root canals were filled after 2 weeks, when a fifth canal was found, located in the buccal cavity. The fifth canal was confirmed to be the mesiolingual root canal by cone beam computed tomography (CBCT) and was found to be curved. After completion of the root canal filling, CBCT was performed, and a three-dimensional root canal image was reconstructed. After 1 week of observation, the tooth was repaired using composite resin filling.

Conclusions

This is the first case presentation of a fifth canal of the mandibular first premolar and advances our understanding of variations in the anatomy of the mandibular first premolar. This case report provides a reference for the treatment of mandibular first premolars.

Prevalence of middle mesial canal and radix entomolaris of mandibular first permanent molars in a western Chinese population: an in vivo cone-beam computed tomographic study

Background

The aim of this study was to investigate the prevalence of the middle mesial canal (MMC) and radix entomolaris (RE) in mandibular first permanent molars in a western Chinese population using cone-beam computed tomography (CBCT).

Methods

A total of 1174 CBCT images of the mandibular first molars were collected from West China Hospital of Stomatology, Sichuan University. The following information was recorded and evaluated: the detection rate and location of the MMC and RE, the curvature of the RE, the canal configuration and bilateral symmetry.

Results

The detection rates of the MMC and RE were 3.41 and 25.04%, respectively, as calculated by individuals, and 1.79 and 22.15%, respectively, as calculated by total teeth. The average curvature in the buccolingual (BL) orientation (40.63 ± 14.39°) was significantly larger than that in the mesiodistal (MD) orientation (17.64 ± 7.82°) (p < 0.05). Of 587 patients, 71.72% (421/587) had bilateral symmetry according to the root canal morphology. The prevalence of three-rooted mandibular first molars was higher in males than in females, while the prevalence of two-rooted mandibular first molars was higher in females than in males.

Conclusions

Our results showed that the RE could be detected in almost 1/4 of the western Chinese population; thus, RE detection requires special attention and careful assessment in endodontic treatment.

Analysis of root canal system of maxillary first and second molars and their correlations by cone beam computed tomography

BACKGROUND/PURPOSE

Understanding the root canal systems of molars and the association of root canal system in adjacent or contralateral molars is important for dental practice. This study aimed to use cone-beam computed tomography (CBCT) to analyze the morphology similarity of root canal systems in the maxillary first and second molars.

METHODS

CBCT images of 1741 maxillary molars in a total of 519 patients were blindly examined to analyze the correlation of root canal systems between maxillary first and second molars as well as the bilateral first and second molars.

RESULTS

The most common type in maxillary first molars is 3R4C (3 roots/4 canals), whereas in maxillary second molars is 3R3C.The symmetry in type of root canals in bilateral maxillary first and second molars were 87.36% and 79.85%, respectively. The similarities of root canal system in adjacent maxillary first and second molars were 53.07% (right side) and 52.58% (left side). The concurrence of MB2 canal in bilateral maxillary first molars is 77.8%, and 35.97% in maxillary second molars. In the 110 patients with MB2 canal in bilateral maxillary second molars, the chance of bilateral MB2 canals in their maxillary first molar is almost 100%.

CONCLUSION

Maxillary first molars have higher prevalence of 3R4C than second molars. The symmetry in bilateral maxillary molars is higher than the similarity in adjacent maxillary first and second molars. Application of CBCT analysis of root canal system can improve endodontic treatment outcomes. The correlation of root canal system between teeth is useful for genetic linkage.

Root and root canal variations of the human maxillary and mandibular third molars in a Chinese population: A micro-computed tomographic study

OBJECTIVES

To investigate the anatomical variations of the root and root canal configuration of the human third molars.

DESIGNS

A total of 130 maxillary and 130 mandibular third molars were collected from a native Chinese population. All teeth were scanned by micro-computed tomography. After 3D reconstruction, the root and canal morphology of each tooth was examined both qualitatively and quantitatively.

RESULTS

For maxillary molars, a single fused root (67 cases, 51.5%) and a single root canal system (64 cases, 49.2%) was most common root/canal form; the typical three-rooted molars were detected only in 33 cases (25.4%), and the secondary MB canals were detected only in 9 molars (6.9%). For mandibular molars, 62 teeth were single-rooted (47.7%) and 42 had a single root canal system (32.3%); 20 singled-rooted and 60 double-rooted molars exhibited independent mesial and distal root canal systems (61.5%), and the type 1-1 canal was the most common configuration for mesial (57 cases) and distal (81 cases) root canal systems. C-shaped canals were detected in 11 maxillary and 36 mandibular single-rooted molars. The mean root surface area, root and crown volume of mandibular third molars were significantly higher than the maxillary third molars (P <  0.01).

CONCLUSION

The root canal system of the third molars may exhibit several anatomic variations. Whereas in most of cases, the degree of the canal differentiation was at a low level, and the canal form was not complicate.

Evaluation of the root and canal systems of maxillary molars in Taiwanese patients: A cone beam computed tomography study

Background

This study evaluated variations in root canal configuration in the maxillary permanent molars of Taiwanese patients by analyzing patients' cone beam computed tomography (CBCT) images. Comparisons were made among these configurations and those previously reported. This information may serve as a basis for improving the success rate of endodontic treatment.

Methods

The root canal systems of 114 Taiwanese patients with bilateral maxillary first or second molars were examined using CBCT images. The number of roots, canals per root, and additional mesiobuccal (MB) canals, as well as the canal configuration were enumerated and recorded.

Results

Of the 196 maxillary first molars examined, three (1.5%) had a single root, two (1.0%) had two roots, and 191 (97.5%) had three separate roots. Out of all first molar roots examined, 44% of mesiobuccal (MB) roots had a single canal and the remainder had a second MB (MB2) canal. Of the 212 maxillary second molars examined, 16 (7.1%) had a single root, 51 (24.2%) had two roots, 143 (67.8%) had three roots, and two (0.9%) had four separate roots. For the MB roots, 92.3% of three-rooted maxillary second molars had a single canal and the remainder had an MB2 canal. In all three-rooted maxillary first and second molars, each of the distal and palatal roots had one canal.

Conclusions

The root canal configurations of the MB roots of maxillary molars were more varied than those of the distobuccal and palatal roots, and the root canal configurations of maxillary second molars were more varied than those of the first molars. These findings demonstrate CBCT as a useful clinical tool for endodontic diagnosis and treatment planning.

Cleaning Effectiveness of a Reciprocating Single-file and a Conventional Rotary Instrumentation System

Objective:

To compare cleaning effectiveness by histological analysis of a reciprocating single-file system with ProTaper rotary instruments during the preparation of curved root canals in extracted teeth.

Methods:

A total of 40 root canals with curvatures ranging between 20 - 40 degrees were divided into two groups of 20 canals. Canals were prepared to the following apical sizes: Reciproc size 25 (n=20); ProTaper: F2 (n=20). The normal distribution of data was tested by the Kolmogorov-Smirnov test and the values obtained for the test (Mann-Whitney U test, P < .05) were statistically analyzed using the GraphPad InStat for the Mac OS software (GraphPad Software, La Jolla, CA, USA).

Results:

There were no significant differences in remaining debris (P > .05) between the two groups.

Conclusion:

The application of reciprocating motion during instrumentation did not result in increased debris when compared with continuous rotation motion, even in the apical part of curved canals. Both instruments resulted in debris in the canal lumen, irrespective of the movement kinematics applied.

Root canal morphology of mandibular first premolar in a gujarati population - an in vitro study

BACKGROUND

Knowledge about root canal morphology and its frequent variations can exert considerable influence on the success of endodontic treatment. The aim of this study was to survey the root canal morphology of mandibular first premolar teeth in a Gujarati population by decalcification and clearing technique.

METHODS

One hundred thirty eight extracted mandibular first premolar teeth were collected from a Gujarati population. After decalcifying and clearing, the teeth were examined for tooth length, number of cusps and roots, number and shape of canal orifices and canal types.

RESULTS

The average length of mandibular first premolar teeth was 21.2 mm. All the teeth had 2 cusps. One hundred thirty four teeth (97.1%) had one root, and just 4 teeth (2.89%) had two roots. Mesial invagination of root was found in 21 teeth (15.21%). One canal orifice was found in 122 teeth (88.4%) and two canal orifices in 16 teeth (11.59%). Shape of orifices was found to be round in 46 teeth (33.33%), oval in 72 teeth (52.17%) and flattened ribbion in 20 teeth (14.49%). According to Vertucci's classification, Type I canal system was found in 93 teeth (67.39%), Types II,III,IV,V,and VI in 11 teeth (7.97%), 5 teeth (3.62%), 4 teeth (2.89%), 24 teeth (17.39%), and 1 tooth (0.72%) respectively.

CONCLUSION

Mandibular first premolar teeth were mostly found to have one root and Type I canal system.

A case of unusual anatomy in second mandibular molar with four canals

Success in root canal treatment is achieved after thought cleaning and shaping followed by the complete obturation of root canal system. Such treatment may be performed in root canal systems that do not comply with the normal anatomical features described in standard textbooks. This article describes the conventional root canal treatment on an unusual mandibular second molar with four root-canals.