Internal and external morphological analysis of fused-rooted mandibular second molars in the Chinese population: A micro-computed tomographic study.

This study investigated the root canal morphology of fused-rooted mandibular second molars based on the pulp chamber floor (PCF) and analysed the correlation between the external morphology of the radicular groove, and the internal morphology of the PCF and root canal configuration. A total of 291 fused-rooted teeth collected from the Chinese population were scanned using micro-computed tomography and a dental operating microscope was used for observing the PCFs. The classification of the PCF and root canal configuration were identified according to modified Min et al.'s and Gao et al.'s classifications, respectively. Additionally, a new radicular groove classification was proposed. The correlation among these morphological characteristics was investigated using the chi-square test and Fisher's exact test (p < 0.05). The results showed that 74.2% of teeth had C-shaped PCFs, while 21.0% had non-C-shaped PCFs. As for the root canal configurations, 37.5% of teeth were merging type, 40.9% were symmetrical type, and 14.8% were asymmetrical type. Statistical analysis revealed a significant correlation between the PCF types and the root canal configurations (p < 0.001). The dominant root canal types for teeth with C-shaped PCFs were merging and symmetrical types, while the asymmetrical type was not identified in non-C-shaped PCFs. In addition, significant morphological association between the root canals and radicular grooves was also revealed (p < 0.001). Teeth with different PCF morphologies exhibit specific patterns of root canal category distribution. Understanding the morphological nuances of the root canal based on the PCF can assist clinicians in predicting and identifying the canal configuration beneath the visible orifice.

The morphology of the pulp chamber floor of permanent mandibular first and second molars in an Indian subpopulation-a descriptive cross-sectional study employing Pawar and Singh classification.

Background: Mandibular molars are multi-rooted teeth with a complex and strenuous root canal anatomy. Because there is relatively negligible literature describing the pulp chamber floor anatomy, predicting the exact anatomical layout and its variations is daunting. A thorough comprehension and knowledge of the same is required for efficacious endodontic treatment consequence. The purpose of this study was to characterise and ascertain the pulp chamber floor anatomy of permanent mandibular first (ManFMs) and second (ManSMs) molars in an Indian population. Methods: On 2,134 extracted human mandibular first (ManFMs = 1,067) and second molars (ManSMs = 1,067), a descriptive cross-sectional investigation was executed. Cleaning and removal of hard and soft tissue debris were performed, followed by flattening the anatomical crown until the pupal architecture was uncovered. A stereomicroscope with a magnification of 4.5 magnification was used to investigate the pulpal anatomy. Statistical analysis was carried out using chi square test, with 95% confidence intervals and a p value of 0.05 considered statistically significant. Results: The majority of the ManFMs showed presence of three canal orifices in 57.73%, followed by four orifices 31.31%, five orifices 8.81%, and six orifices 2.15%. For ManSMs, majorly three orifices were found in 39.83% specimens, followed by two orifices in 37.39%, four orifices in 16.31%, and single root canal orifice was observed in 6.47%. The mesio-buccal, mesio-lingual, disto-buccal, disto-lingual canal orifices exhibited round and oval shapes in both ManFMs and ManSMs. The shape was predominantly oval with a single distal canal orifice (84.25% ManFMs and 74.16% ManSMs). In ManSMs, among the single root canal orifice, 66.66% were round in shape and 33.34% were C-shaped. In ManSMs with two root canal orifices, mesially 79.44% exhibited oval and 20.56% round shape. Distally, 74.16% were oval and 25.84% were round. The shapes of the access cavities for ManFMs were rectangular in 46.67% and triangular in 53.33%. For the ManSMs, the access cavities were triangular in 39.83%, rectangular in 16.31% and non-classified (others) in 43.86% of specimen. In both ManFMs and ManSMs, the pulp chamber floor morphology was predominately Y shaped (57.73% and 39.83%) according to the Pawar and Singh classification© of pulp chamber floor anatomy. Conclusion: Our study indicated that the orifices on the pulp chamber floor are arranged in a typical manner, supporting the proposed categorization. Furthermore, description of the anatomical patterns of the pulp chamber guides the clinicians in chair-side treatment decisions.

Endodontic treatment of various palatal roots in maxillary molars: Case series and clinical experience.

BACKGROUND AND OVERVIEW: The purpose of this article is to present the variations in maxillary molar palatal root canals and provide a reference for the possible variations in root canal treatment. CASE DESCRIPTION: Five rare cases with palatal canal variation presented in this case series received nonsurgical endodontic treatment successfully. These case reports highlight that understanding and managing the different types of canal configurations in palatal roots of maxillary molars is essential to successful root canal treatment. We tried 2 methods of examining the palatal canal variation to provide examples for clinicians in diagnosing and treating similar cases. CONCLUSIONS AND PRACTICAL IMPLICATIONS: The outline form of the access cavity and the shape of the pulp chamber floor are important factors for identifying variations in root canal number. Moreover, cone-beam computed tomography can help in detecting variations in root canals.

New classification for pulp chamber floor anatomy of human molars.

Comprehensive knowledge of the entire root canal system is an essential prerequisite for successful routine endodontic treatments. The internal and external morphological configurations of roots and root canals are quite complex. Thus, several classifications have been put forth by researchers to appropriately understand the distinguishable features of root and root canal systems of multirooted teeth. Until now, the researchers have proposed new classification systems for a thorough understanding of the root canal systems, mainly concentrating on the root canal anatomy and anomalies. Moreover, with the advent of newer digital imaging systems, these classifications are more reproducible and relevant. They have further gained importance for the clinicians by acting as an aid in decision-making based on evidence-based dentistry. However, these classifications are primarily focused on the root canals, but none have assessed the anatomy of the pulp chamber floor. This review article delineates a novel Pawar and Singh molar pulp chamber floor classification© for the anatomy of maxillary and mandibular molars to ease the clinician's skills and further increase the prevailing literature for the benefit of researchers.

A quantitative and diametral analysis of human dentinal tubules at pulp chamber ceiling and floor under scanning electron microscopy.

The purposes of this study are (i) to evaluate and compare the dentinal tubule density, tubule diameter and percentage area of dentin occupied by tubules at the pulp chamber ceiling and floor; and (ii) to evaluate the effects of age on the number and dimensions of tubule openings. Twelve intact, human mandibular third molars were recruited. Six teeth belonged to patients up to 30 years of age and six teeth belonged to patients over 50 years. Scanning electron microscopic evaluations were made at two different locations: the pulp chamber ceiling and floor. The pulp chamber ceiling presented higher tubule density (P < 0.0001) and greater percentage area of dentin occupied by tubule openings (P < 0.0001) compared to the pulp chamber floor. Also, younger age group had greater tubule diameter (P < 0.0001), higher tubule density (P < 0.0001) and greater percentage area of dentin occupied by tubule openings (P < 0.0001) compared to older age group. Pulp chamber ceiling presents higher tubule density and greater area of exposed tubules. In younger people, the pulp chamber floor presents considerably high tubule diameter. The number and dimensions of dentinal tubule openings significantly decrease with age.

Association between dentin thickness and presence of accessory foramina in human permanent mandibular molars

The roots and periodontal system in human dentition are closely correlated from the early stagesof dental formation, maintaining this connection after teeth are established in the oral cavitythrough the apical foramen or other communications. Aim: Therefore, the aim of this study was toevaluate the correlation between the presence of foramina on the pulp chamber floor surface andin the furcation region and the thickness of dentin in this area. Methods: Forty sound permanentmandibular molars were submitted to scanning electron microscopy (SEM) to determine thepresence of foramina on the pulp chamber floor and in the furcation region, and to correlate thepresence of foramina with the variation in wall thickness in these regions. Results: The resultsshowed a mean thickness of 2.16 mm for the teeth analyzed and a 25% frequency of foramina onthe pulp chamber floor and 92.5% in furcation area, with only 22.5% showing foramina on bothsides. The foramina found on both surfaces showed varied diameters and shapes and locationsdispersed throughout the area. Conclusions: There was no significant difference between themean thicknesses of teeth featuring foramina and those without foramina.