ABSTRACT
Background: This study evaluated the interface between fresh eugenol/bioceramic sealer-conditioned coronal dentin and high-viscous glass-ionomer cement (HVGIC), treated with various dentin conditioners (saline, 10% polyacrylic acid, and 37% phosphoric acid). Materials and Methods: Standard endodontic access preparation and instrumentation were done in 21 freshly extracted mandibular molar teeth in this in vitro study. Teeth were divided into two interventional groups (n = 9/group), based on the type of sealer (zinc oxide eugenol [ZOE]/bioceramic [BioRoot RCS] sealer) used for obturation. Samples were further subdivided based on the type of dentin-conditioning procedures performed (saline/10% polyacrylic acid/37% phosphoric acid). Post dentin conditioning, the access cavity was sealed with HVGIC. Later, material-dentin interfacial analysis and elemental analysis were done using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy. Results: The interfacial SEM images of HVGIC layered over B-RCS/ZOE sealer-conditioned dentin, treated with saline, showed predominantly adhesive debonding failures, whereas cohesive debonding was observed with polyacrylic and phosphoric acid. In the elemental analysis, the intensity of zirconium (depicting the residue of B-RCS)/zinc (depicting ZOE sealer) was very high on the dentin side treated with saline, in comparison to the dentin treated with polyacrylic and phosphoric acid. Furthermore, the intensity of elements from HVGIC was low on the dentin side of the groups with saline, whereas these elements showed maximum penetration into the dentin when treated with phosphoric acid. Conclusion: Conditioning of the endodontic access cavity using 37% phosphoric acid immediately postobturation resulted in higher penetration of HVGIC into the dentin, in comparison to the other dentin conditioners.
ABSTRACT
OBJECTIVE: The aim of the study was to evaluate the prevalence of root canal isthmus (RCI) and measure the interorifice distance (IOD) between the root canals. Additionally to correlate IOD with the RCI in human permanent teeth using conebeam computed tomography (CBCT) in an Indian sub-population (Chennai). MATERIALS AND METHODS: A total of 5881 teeth from 280 CBCT full mouth scans were analyzed. The presence or absence of complete and incomplete RCI of each tooth was identified using the map-reading strategy. IOD was calculated by measuring the distance between the center of each root canal orifice to that of the center of the adjacent orifice at the level of the cementoenamel junction using the axial and sagittal sections. Chi-square analysis and correlation statistics using Spearman's rank-order test was done (P < 0.05). RESULTS: High prevalence of RCI was found in maxillary first premolars, mesial root of mandibular molars, and mesiobuccal root of maxillary first molars, while its prevalence was low in maxillary canines and mandibular premolars and absent in maxillary incisors. RCI was predominantly seen in the cervical and middle third of the root canal in all the teeth evaluated. A weak negative correlation was established between the IOD and RCI for maxillary premolars, whereas a weak positive correlation was seen in maxillary first molars and mandibular second molars. CONCLUSION: The prevalence of RCI was high in the posterior teeth in comparison to the anterior teeth in the present study. There was no strong correlation between IOD and RCI in all the teeth evaluated.
