METHODS: Extracted human primary maxillary second molars (n = 57) were scanned using micro-computed tomography and reconstructed to produce three-dimensional models. Each root canal system was analysed qualitatively according to Vertucci's classification.
RESULTS: 22.8% (n = 13) of the sample presented with the fusion of the disto-buccal and palatal roots; of these, Type V was the most prevalent classification. For teeth with three separate roots (n = 44), the most common root canal type was Type 1 for the palatal canal (100%) and disto-buccal canal (77.3%) and Type V for the mesio-buccal canal (36.4%). Overall, 7% (n = 4) of mesio-buccal canals were 'unclassifiable'.
CONCLUSION: The root canal systems of primary maxillary second molars were not only complex but had a range of configurations that may contribute to unfavourable clinical outcomes after endodontic treatment.
Materials and Methods: One hundred and sixty endodontically treated maxillary central incisors embedded in acrylic resin with decoronated root portion were taken for the study. The postspaces were prepared according to standard protocol. The samples were divided into two groups according to the post material: glass-fiber post and Quartz fiber post. These groups were further subdivided on the basis of coronal extension of 4 and 6 mm for glass fiber and Quartz fiber posts, respectively. The posts were then luted with dual-polymerizing resin cement followed by core buildup. Samples were subjected to increasing compressive oblique load until fracture occurred in a universal testing machine. Data were analyzed with one-way ANOVA and independent Student's t-test. Analysis was done using SPSS version 15 (SPSS Inc., Chicago, IL, USA) Windows software program.
Results: Glass fiber post with coronal extension of 4 mm (182.8 N) showed better results than with 6-mm length (124.1 N). Similarly, in quartz fiber posts group, 4-mm postlength (314 N) was better when compared with 6 mm (160 N). The 4-mm coronal extension of quartz fiber post displayed superior fracture resistance.
Conclusions: Glass fiber posts showed better fracture resistance than Quartz fiber posts. 4-mm coronal length showed more fracture resistance than 6 mm.
METHODS: A total of 208 CBCT images were examined retrospectively. Prevalence of an extra root/canal and internal morphology based on Vertucci's classification were observed in human maxillary and mandibular permanent teeth. Variations in the external and internal morphology were compared in relation to gender and tooth side (left vs right) using Pearson Chi-square and Fisher's exact tests with significance level set at p root (radix entomolaris) were detected in 1.9, 19.5 and 21.4% of mandibular first molars, respectively. The prevalence of a C-shaped canal was observed in 48.7% of mandibular second molars. Females displayed significantly higher prevalence of a C-shaped canal in the right mandibular second molars than males (p root anatomy and root canal morphology were observed in relation to gender and tooth side.
CONCLUSIONS: Wide variations in the root canal morphology exist among Malaysians. CBCT is a clinically useful tool in the identification of external and internal morphological variations in the human teeth.
Objectives: The aim of this review was to compare the various root and root canal morphology classifications, their advantages, limitations, and clinical and research implications. Data Sources and Selection. An extensive literature search was conducted on PubMed and Scopus to identify the published data on root and root canal classification systems published until 1 May 2020 using keywords, root canal classification system, classification systems for root canals, and root morphology. The related literature was reviewed and then summarized. Data Synthesis. Several studies have analysed and detailed root and root canal classifications and further added new subsystems, works of Weine et al. (1969) and Vertucci et al. (1974). Besides, Sert and Bayirli (2004) added supplementary types to Vertucci's classification system. A new classification was most recently introduced by Ahmed et al. (2017) involving the use of codes for tooth numbering, number of roots, and canal configuration.
Conclusions: Weine et al. classified only single-rooted teeth, without considering multirooted teeth and complex configurations. Vertucci's classification included complex configurations, with Sert and Bayirli adding further complex supplemental types. Ahmed et al.'s classification simplifies classifying root and canal morphology while overcoming the limitations of several previous classification systems making it beneficial for implementation in dental schools.