Assessment of the Dentinal Surface Adaptation Efficacy of Different Obturation Systems with Bioceramic Sealer: A Scanning Electron Microscope Study.

AIM: Aim of this study was to evaluate the dentinal surface adaptation effectiveness of different obturation methods with bioceramic sealer. MATERIALS AND METHODS: Sixty recently removed human permanent premolars of the mandible having a solitary, straight as well as completely produced root were chosen on the basis of clinical/radiographic evaluation. The coronal parts of the premolars were subjected to sectioning at the cementoenamel junction (CEJ) with the aid of a water-cooled diamond disk. The regular access opening was done, following which the working length was visually estimated by deducting 1 mm from the length of a 10 size K-file (Dentsply, OK, USA) at the apex. Subsequent to preparing the radicular canal, the premolar specimens were randomly allocated to one of the following three groups. Group I: Lateral compaction (LC) technique; group II: Warm vertical compaction (WVC) technique; and group III: Thermafil obturation technique. Following obturation, the samples were subjected to sectioning in the horizontal direction at three dissimilar points as follows: First at the cervical third, then at the middle, and at the apical third employing a minitom under water irrigation to put off overheating. Internal spaces amid the radicular dentin as well as the obturating agents were appraised with the use of a scanning electron microscope (SEM). RESULTS: Intragroup analysis showed that higher gaps were noted at the coronal level (2.30 ± 0.04), in pursuit by middle part (1.12 ± 0.02) and apical third (0.70 ± 0.02) for the LC method. With the WVC procedure, higher gaps were situated in the coronal level (1.96 ± 0.07), again in pursuit by middle part (1.02 ± 0.02) and apical third (0.86 ± 0.04). Even with the Thermafil obturation method, higher gaps were noted at the coronal level (0.92 ± 0.10), in pursuit by middle part (0.67 ± 0.05) and apical third (0.57 ± 0.01). No statistically significant difference was noted within the group. Upon intergroup comparative assessment of dentinal surface adaptation with dissimilar obturation systems at coronal, middle and apical thirds, there was a statistically noteworthy disparity amid the groups (p <0.001). CONCLUSION: This research arrived at a conclusion that the most superior dentinal adaptation of bioceramic sealer was procured when the Thermafil obturation method was employed for obturating the root canals compared to the WVC technique as well as the LC technique. CLINICAL SIGNIFICANCE: Numerous endodontic substances have been promoted for obturating the root canal areas. Majority of the methods use a core substance, in addition to a sealer. Despite the type of core agent, a sealer indispensable to each technique offers a fluid-tight sealing. The oral physicians' comprehension of the characteristics of the endodontic sealer plus method used, enhances the therapeutic effect.

Assessment of the Efficacy of Different Desensitizing Agents on Dentinal Tubules Occlusion- An In vitro Study.

Aim: The aim of the current research was to evaluate the effectiveness of three desensitizing agents on the occlusion of dentinal tubules. Materials and Methods: Eighty human maxillary and mandibular permanent premolar teeth that were subjected to extraction in the course of orthodontic treatment were utilized in this study. The teeth were subjected to sectioning by employing a double-sided diamond disk. A block was procured from every even cervical dentinal surface with dimensions of 4 mm × 4 mm × 3 mm (L × B × H) by sectioning the tooth transversely. Further, 35% phosphoric acid was utilized for 30 s to cause dentinal etching, thereby exposing the dentinal tubules. The blocks of dentin were assigned at random to one of the following four groups (n = 20): group I: control, group II: bioactive glass containing desensitizing agent, group III: 1% nano-hydroxyapatite containing desensitizing agent, group IV: tri-calcium phosphate-containing desensitizing agent. The exterior of the specimens was scanned and evaluated using a scanning electron microscope. Results: 1% nano-hydroxyapatite-containing desensitizing agent (2.04 ± 0.08) exhibited higher mean dentinal tubular blockage, followed by the bioactive class-containing desensitizing substance (2.26 ± 0.19), tri-calcium phosphate desensitizing agent (2.84 ± 0.10), and the control group (4.18 ± 0.12) in that order. Amid the experimental groups employing the various desensitizing substances, there were significant differences statistically with P < 0.001. Conclusion: The current research concluded that each of the three desensitizing agents was efficient in dentinal tubular occlusion regardless of their different chemical constitution. However, it was noted that 1% nano-hydroxyapatite-containing desensitizing agent was marginally superior to the bioactive glass- and tri-calcium phosphate-containing desensitizing agents.

Glucose and Serum Deprivation Led to Altered Proliferation, Differentiation Potential and AMPK Activation in Stem Cells from Human Deciduous Tooth.

Stem cell therapy is an evolving treatment strategy in regenerative medicine. Recent studies report stem cells from human exfoliated deciduous teeth could complement the traditional mesenchymal stem cell sources. Stem cells from human exfoliated deciduous teeth exhibit mesenchymal characteristics with multilineage differentiation potential. Mesenchymal stem cells are widely investigated for cell therapy and disease modeling. Although many research are being conducted to address the challenges of mesenchymal stem cell therapy in clinics, most of the studies are still in infancy. Host cell microenvironment is one of the major factors affecting the homing of transplanted stem cell and understanding the factors affecting the fate of stem cells of prime important. In this study we aimed to understand the effects of serum deprivation in stem cells derived from human deciduous tooth. Our study aimed to understand the morphological, transcriptional, cell cycle and stemness based changes of stem cells in nutrient deprived medium. Our results suggest that stem cells in nutrient deprived media undergo low proliferation, high apoptosis and changed the differentiation potential of the stem cells. Serum deprived mesenchymal stem cells exhibited enhanced chondrogenic differentiation potential and reduced osteogenic differentiation potential. Moreover, the activation of key metabolic sensor AMP-activated kinase (AMPK) leads to activation of transcription factors such as FOXO3, which leads to an S phase quiescence. Serum deprivation also enhanced the expression of stemness related genes Sox2 and c-Myc.