Root canal configuration of deciduous mandibular first molars--an in vitro study

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.

Deciduous Molars Complexity Anatomy Reveled by Computed Microtomography

OBJECTIVE

 The aim of this study was to analyze the internal morphology of deciduous molars through the use of computed microtomography in a sample from Rio de Janeiro.

MATERIAL AND METHODS

 Thirty maxillary and 30 mandibular deciduous molars (n = 60), divided in first and second primary molars, were scanned by computed microtomography. The teeth were evaluated for root number, root canals, Vertucci classification, root curvature, presence of lateral canals, furcation dentin thickness, structure model index (SMI), volume, and canal surface area.

RESULTS

 The results showed 100% of maxillary molars had three roots and Vertucci type I canal was more prevalent in this group. In the mandibular ones, type IV was more frequent in the mesial root and class I in the distal root and the cavo-interradicular canal occurred in 2 specimens. Dentin thickness in the furcation region measured 1.53 and 1.59 mm in the maxillary and mandibular, respectively. Volume and area parameters varied according to the evaluated canals and SMI demonstrated that all canals had a cylindrical shape.

CONCLUSION

 More detailed information about the internal anatomy of the primary molars has been described, which may help strategies in the preparation of these root canals.

Cone-Beam Computed Tomography (CBTC) Applied to the Study of Root Morphological Characteristics of Deciduous Teeth: An In Vitro Study

Pulp therapy in primary teeth is a challenge for a dentist, therefore, a better understanding of the anatomical characteristics of this tissue is essential to remedy these deficiencies. The aim of this study was to determine the morphological peculiarities of the root canals of extracted deciduous molars by Cone-Beam computed tomography (CBCT). As such, healthy molars without physiological resorption were collected and sanitized. After analyzing descriptive and inferential statistics, the results show that 56% of lower molar roots have a Weine’s type III canal configuration; the upper and lower second molars are significantly larger compared to the first, with a mean of 8.318 (±1.313) mm and 7.757 (±1.286) mm, respectively. Additionally, the palatine canals exhibited greater volume than the others, with a mean of 3.687 mm³. There are multiple discrepancies in the molars that have been studied in other investigations. The presence of a supernumerary root in the mandibular molars, a smaller dimension of the root canals and a more evident apical angulation are more obvious. The discovery of great anatomical versatility in the posterior dental group is an aspect applicable to root therapy.

Morphological measurements of anatomical landmarks in human maxillary first molar pulp chambers and evaluation of number of pulp canal orifices using spiral computed tomography: An in vitro study

Context:

Comprehensive understanding of the anatomic position of pulp canal orifices and the measurements of the molar pulp space may maintain the pulp health during conservative tooth preparation and minimize the possibility of mishaps during endodontic therapy.

Aims:

The idea of the present study was to analyze the morphological measurements of anatomical landmarks in human maxillary first molar pulp chambers and evaluation of number of pulp canal orifices using three-dimensional spiral computed tomography (SCT).

Subjects and Methods:

One hundred and thirty extracted intact human adult maxillary first molars were chosen from the North Indian population and were analyzed using SCT in axial and coronal sections.

Statistical Analysis Used:

Standard deviation, mean, and coefficient of variance were calculated. Interobserver reliability was evaluated using kappa value to avoid any bias.

Results:

The results from our study showed that 69.23% of the sample teeth had four canal orifices, the mesial and distal pulp horns were present at an average distance of 0.80 ± 0.36 mm and 0.41 ± 0.34 mm, respectively, above the cementoenamel junction (CEJ), and the mean distance from the central groove of central fossa to furcation and the central groove of central fossa to the pulp chamber's roof was 8.37 ± 0.33 mm and 3.87 ± 0.29 mm, respectively. The average distance of the pulp chamber's floor from the furcation was found to be 2.47 ± 0.11 mm. The highest degree of variance was observed in case of relation of CEJ to pulp horns, i.e., 44.85% and 82.60%.

Conclusions:

The dimensions observed in this study and its resemblance to the various studies reported in literature shift the fundamental anatomic approach to a more systemic quantifiable approach to the endodontic maxillary first molar access preparation.

Single-rooted primary first mandibular molar

Morphological variations like single-rooted molar in primary dentition are scarce. Understanding the root canal anatomy and variations is necessary for successful root canal therapy. The purpose of the present article is to report successful endodontic treatment of primary left mandibular first molar with an abnormal morphology of a single root. This case report highlights the importance of knowledge and its applications in the management of anomalous anatomic variants which play a crucial role in the success of endodontic treatment.

Unilateral single-rooted primary mandibular first molar

A 4-year-old boy reported food lodgement and pain in the lower left back tooth region. On examination, a deeply carious tooth with food lodgement was seen. On oral examination, numbers of teeth were found to be carious and required restorations and endodontic treatments according to radiographic evaluation. Radiograph of mandibular left first deciduous molar revealed an unusual morphology of root. It was single-rooted and presented with Vertucci's class I canal. The tooth was treated by pulpectomy followed by a stainless steel crown. All other carious teeth were treated as planned.

Are referred inaccessible human primary molar teeth really inaccessible?

Despite a body of compelling evidence pertaining to the root canal accessibility of primary teeth, the number of referrals for inaccessibility of primary molars is considerable. The aim of the present study was to evaluate the prevalence of true and false primary molar inaccessibility among subjects who had been referred by general and pediatric dentists. We examined 199 primary molars in 156 patients (87 males, 69 females) aged 3-7 years who were referred by 215 general and 35 pediatric dentists. Problems related to inaccessibility were recorded for each tooth and any individual canal. One hundred seventy-five inaccessible teeth (87.9%) were successfully rehabilitated to accessible status (P < 0.001). The most frequent cause of inaccessibility was an inappropriate access cavity (42.3%), followed by difficult canals (32.6%) and orifice calcification (25.2%). The tooth most frequently reported as inaccessible was the maxillary first molar (40.2%), and that least frequently reported was the mandibular second molar (11.6%). The distobuccal canal of the maxillary first molar and the mesiolingual canal of the mandibular first molar were the most commonly inaccessible canals (P < 0.001). Only 1 out of 8 teeth referred as inaccessible was truly inaccessible. It seems that root canal inaccessibility is mostly attributable to lack of expertise among individual practitioners.

Instrument fracture in root canals - where, why, when and what? A study from a student clinic

AIM

To investigate the incidence of instrument fracture during nonsurgical root canal treatment performed by undergraduate dental students and to assess the outcome of the treatment if the remaining fragment was left or removed from the root canal.

METHODOLOGY

A retrospective analysis was performed by reviewing assessment forms (n = 3854) filled out for each root canal treatment over a 10-year period (1997-2006) at the University of Bergen, Norway. Based on the assessment forms, all instrument fractures and data concerning type and dimension of the fractured instruments were identified. Moreover, the affected tooth, root, root curvature and the vertical level of the fragment in the root canal were recorded. To assess the outcome of the root canal treatment, radiographs taken at follow-ups were evaluated by two individual examiners.

RESULTS

The overall incidence of instrument fracture during the period was 1.0% on a tooth level. Instrument fracture occurred significantly more often in molars and in teeth rated as difficult preoperatively. Of all instrument fractures, 39.5% were located in the mesio-buccal canals of molars, and 76.5% of the fragments were located apically. A significant high percentage of instruments of small apical diameter (sizes 006-015) fractured in relative straight root canals. The treatment was successful in 71.4% of the cases where the instrument fragment was removed, but only in 56.5% of the cases where the fragment remained in the root canal. Significantly more instruments were removed from teeth with a primary infection (P ≤ 0.05). The success rate for teeth with instrument fracture was 72.7% for vital teeth, 58.3% for primary infected teeth and 42.9% in retreatment cases.

CONCLUSIONS

Within the limits of the present study, the results indicate that the preoperative diagnosis is important for the final treatment outcome and that removal of the fragment is important in cases with primary infection.

Evaluate root and canal morphology of primary mandibular second molars in Chinese individuals by using cone-beam computed tomography

BACKGROUND/PURPOSE

More detailed knowledge of root and canal morphology is important in order to improve the success in the endodontics of primary teeth. The purpose of this study was to evaluate the root and canal morphology of primary mandibular second molars (PMSMs) in a Chinese population using cone-beam computed tomography (CBCT).

METHODS

CBCT images, which had been obtained previously in the West China Hospital of Stomatology at Sichuan University, Chengdu, China between May 2009 and December 2011, were screened retrospectively. Finally, 283 individuals-207 male and 76 female with a mean age of 7.2 years (range 3-10 years)-and 487 PMSMs with clear images of root and canal morphology were enrolled. The number of roots and morphology of canals were recorded. The patient's gender, and the symmetry and frequency of three roots in PMSMs were analyzed.

RESULTS

The majority of PMSMs had two (72.28%) or three roots (27.52%). The symmetrical incidence of three-root PMSMs in this Chinese population was 50.65%. There is no difference between genders in the prevalence of an extra root and the incidence of symmetry (p > 0.05). Of the individuals enrolled, 25.26% of PMSMs had three canals and 73.31% had four canals. The root canal systems of the PMSMs in the present study were categorized into seven variants.

CONCLUSION

This study indicated that three-rooted PMSMs occur frequently in the Chinese population. There was no difference between the two genders on incidence and symmetry. The majority of PMSMs have three to four canals and the diversity of the root canal variants should be considered when performing clinical procedures. CBCT is a good option for studying the root and canal morphology of primary teeth.

Deciduous Mandibular Second Molar with Supernumerary Roots and Root Canals Associated with Missing Mandibular Permanent Premolar

Morphological variations like additional roots and root canals in human deciduous dentition are rare. Knowledge of the morphology, variation of root and root canals of deciduous teeth are useful for successful endodontic treatment and exodontia. Presented here is a case report of the supernumerary roots and additional root canals of deciduous mandibular second molar (85) with congenitally bilateral missing of mandibular permanent second premolar (35 and 45) tooth bud.

An in vitro study of root and canal morphology of human deciduous molars in an Iranian population

Dental caries is the most common chronic childhood disease. Deep caries and dental trauma are the two main etiologic factors responsible for pulp involvement. Better knowledge of the morphology of the root canals of deciduous teeth can improve the outcome of pulp treatment. In this study, 90 deciduous molar teeth (27 first mandibular molars, 27 first maxillary molars, 22 second mandibular molars and 14 second maxillary molars) were prepared using the clearing technique, and then dye was injected into the pulp cavity of each tooth. The roots of the teeth were examined under a stereomicroscope at × 10 magnification from different aspects. Measurements of root length and angulation were also recorded, and the data were analyzed using SPSS-16 software. Deciduous molar teeth in all four classes showed variability in the number of roots and root canals, and also differed in mean root length and angulation. Type I and IV root canal configurations were observed in the samples, and different types of curvature were recorded for the root canals in all four classes. As deciduous molar teeth exhibit morphologic differences from permanent teeth, a thorough knowledge of the root canals in the former can improve the outcome of pulp treatment.