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Background: Several designs of access cavity have been evolved in the recent past with the concept of minimal tooth tissue removal which would improve the root canal treated teeth fracture resistance. Aim: To investigate the effect of conservative design access cavity during the instrumentation of maxillary molar root canals. Materials and Methods: Eighty noncarious maxillary molars were assigned to the traditional and conservative access groups (n = 40 each). After designated access preparations, the teeth were immersed in Lugols's solution for staining the pulp tissue. Root canal instrumentation was performed with TruNatomy file system. Pre- and postinstrumentation nano-computed tomography (CT) images were taken and reconstructed using CT-An software. Root canals volumetric analysis was done with CT-Vol software. The analysis of the data was dealt with Shapiro-Wilk test and independent t-test. Results: The volume of pulp canal space before and after instrumentation changed significantly between the traditional and conservative access design groups, according to an independent t-test. In comparison, the mean volume of dentin removed was much larger in the TAC group (P = 0.0016). The independent t-test manifests difference significantly between traditional endodontic access cavity (TAC) and conservative access cavity (CAC) with percentage of unprepared canal walls. The mean percentage of unprepared area was significantly lesser in TAC group as compared to CAC group (P = 0.0022). Conclusion: The volume of dentin removed was greater in TAC than with the CAC design. The amount of untouched canal wall area was significantly higher in conservative access design than with the traditional access design group.
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Background To obtain prolonged clinical success with composite restorations, better bonding of resin to the tooth substrate is crucial. Aim The study was aimed to evaluate the microtensile bond strength (µTBS) of bulk-fill composite resin restorations when bonded to a cavity previously restored with amalgam, comparing with that of freshly prepared dentin. Materials and method Mesio-occlusal cavity preparations were done on 80 extracted human mandibular molars with a buccolingual width of 4 mm and a 1.5 mm axial depth by placing the gingival seat 0.5 mm coronal to the cementoenamel junction (CEJ) and were restored with fine-grain amalgam alloy. After thermocycling, the amalgam restorations were removed. Disto-occlusal cavities with similar dimensions of mesial cavities were prepared, and both the proximal surfaces were filled with bulk-fill composite using either etch-and-rinse or self-etch adhesives. Following thermomechanical cyclic loading, all the teeth were sectioned for µTBS testing. Bond strength data expressed in megapascals (MPa) were subjected to statistical analyses using analysis of variance (ANOVA) and Tukey's multiple post-hoc tests. Results The total-etch adhesive exhibited statistically higher bond strength values to both dentin substrates compared to self-etch adhesives (p<0.05). Failure mode analysis reported more of adhesive failures. Conclusion The µTBS of bulk-fill composite resin restorations bonded to a cavity previously restored with amalgam was significantly lower than that of freshly prepared dentin. Total-etch adhesives bond strength was higher than self-etch adhesives to both the substrates tested.
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BACKGROUND: Posttreatment endodontic pain has been reported in 25%-40% of all endodontic patients. Effective management of endodontic pain represents a continuing challenge. AIM: To evaluate and compare the efficacy of preoperative single dose of nonsteroidal anti-inflammatory drug, piroxicam (20 mg), with two types of corticosteroid drugs - dexamethasone (4 mg) or deflazacort (30 mg) - for the prevention and control of postendodontic pain. MATERIALS AND METHODS: A total of 132 volunteers selected for nonsurgical root canal therapy were randomly divided into the following four groups (n = 30 each) according to preoperative medication given: Group 1, piroxicam (20 mg); Group 2, dexamethasone (4 mg); Group 3, deflazacort (30 mg); and Group 4, placebo. The preoperative medications were administrated 1 h before the start of standard endodontic treatment. Patients were instructed to complete a pain diary using Visual Analog Scale preoperatively and at 6-, 12-, 24-, 48-, and 72-h intervals after root canal instrumentation. STATISTICAL ANALYSIS: The correlation between preoperative endodontic pain to postoperative pain and pair-wise comparison of four groups was evaluated by Kruskal-Wallis analysis of variance test followed by Mann-Whitney U-test. RESULTS: Compared to the placebo group, piroxicam, dexamethasone, and deflazacort resulted in a statistically significant reduction in postendodontic pain at 6, 12, and 24 h (P < 0.05). CONCLUSION: Preoperative single oral dose of piroxicam or dexamethasone or deflazacort is equally effective in controlling postendodontic pain.
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INTRODUCTION: Infiltration of early enamel lesions by materials having remineralizing capacity seems to improve aesthetics and arrests caries progression. AIM: To evaluate and compare the surface microhardness and penetration depth of a low viscosity resin and colloidal silica nanoparticle infiltrates into artificially created white spot lesions. MATERIALS AND METHODS: Forty extracted human central incisors were embedded in acrylic resin blocks exposing the labial surfaces of the crowns. The specimens were immersed in demineralizing solution for 96 hours to create white spot lesions on labial surfaces. The samples were then divided into two groups (n=20 each), where in Group 1-resin infiltration (ICON DMG, Hamburg, Germany) and Group 2-colloidal silica infiltration (Arrow Fine chemicals, Rajkot, Gujarat, India) was done. Samples were subjected to vicker's microhardness testing at baseline, after demineralization and after treatment with resin or colloidal silica infiltrates. Then, the crowns were sectioned longitudinally and penetration depth of the infiltrants was measured using confocal laser scanning microscope and compared the readings to lesion depth. All the collected data was subjected to statistical analysis using t-test. RESULTS: Resin infiltration group showed significantly greater increase in microhardness compared to colloidal silica infiltration (p=0.001). The percentage of penetration of the resin group was 67.14% and that of colloidal silica group was 54.53% indicating significant difference between the two. CONCLUSION: Resin infiltrates performed better in regaining the baseline microhardness and penetrating deep into the porous white spot lesions, when compared to colloidal silica infiltrates.