RESUMEN
Aim: To evaluate the effect of natural antioxidants as final irrigants on the push-out bond strength of epoxy resin-based sealer to the hypochlorite treated dentin. Methods: Eighty single-rooted human mandibular incisors were prepared using ProTaper Gold (Dentsply, TN, USA) and an irrigation protocol including 3% NaOCl, followed by ethylenediaminetetraacetic acid (EDTA), and 3% NaOCl. The groups (n =20) were divided according to the final irrigant used: Group 1: None (Control); Group 2: 5% sodium ascorbate, Group 3: 5% grape seed extract (GSE); and Group 4: 5% pine bark extract. The obturation of root canals was performed using gutta-percha and AH Plus (Dentsply DeTrey, Germany). Bond strength was evaluated using the push-out test under the universal testing machine at a crosshead speed of 0.5 mm/min, and statistical analyses were performed using one-way ANOVA. The p-value significance was evaluated by Tukey's post hoc test (p<0.01). Results: Mean push-out bond strength values were compared in all the groups, and there was a statistically significant improvement in the experimental final irrigating groups. 5% pine bark extract had improved bond strength than the other groups, and the least bond strength was observed in the control group. Conclusion: The irrigation protocols and naturally derived antioxidants affected the resin-based sealer's bond strength to root dentin. It was observed that the use of antioxidants effectively reversed the compromised bond strength of resin-based sealers to root dentin. 5% pine bark extract application showed better bond strength.
RESUMEN
Aim: Evaluate the effect of different chromatic filters of the dental operating microscope on the volumetric shrinkage, surface micro-hardness, and depth of cure of bulk-fill composite. Methods: Bulk fill composite specimens of 4 mm depth, 4 mm width, and 4 mm length were prepared. Five groups were designed based on a light source under which composite samples were condensed. Group 1: dental chair light without filter, Group 2: microscopic light without filter, Group 3: microscopic light with a yellow filter, Group 4: microscopic light with a green filter, Group 5: dental chair light with a red filter. After condensation, the samples were subjected to curing using Bluephase NM curing light. The parameters like volumetric shrinkage, surface hardness, and depth of cure were measured for all the samples. The results were subjected to statistical analysis using one-way ANOVA, followed by post-hoc Tukey tests. Results: Group-2 showed the highest mean volumetric shrinkage (14.514%), surface micro-hardness (58.065 kg/m2), depth of cure (0.831%), whereas group-5 showed the least volumetric shrinkage (7.386%), surface micro-hardness (46.536 kg/m2), and depth of cure (0.789%). Working time was 40 seconds for group-2, whereas the remaining groups were allowed to complete 1-minute condensation. A statistically significant difference was shown between groups 1 and 5 (p=0.050), 2 and 5 (p=0.007) for volumetric shrinkage. Regarding surface micro-hardness, a statistically significant difference was observed between all the groups (p=0.001) except group-3, group-4 (p=0.100). There was no statistically significant difference between all the groups except group 2 and 5 for depth of cure (p=0.016). Conclusion: Microscope light without filter showed the highest surface hardness and depth of cure. However, the highest volumetric shrinkage and lesser working time were also observed, which are undesirable. Use of filters during composite manipulation showed less detrimental effects on depth of cure, volumetric shrinkage and working time. Overall, composite condensed under filters showed acceptable properties.
RESUMEN
Background@#Various instrument kinematics used in single-visit endodontics influence the occurrence of pain after endodontic therapy. This study aimed to evaluate the occurrence of pain after mechanical instrumentation with Hyflex EDM (HEDM) and WaveOne Gold (WOG) during single-visit endodontic therapy. @*Methods@#Sixty patients diagnosed with asymptomatic irreversible pulpitis and normal apical tissues in mandibular premolar teeth were included in the study for single-visit root canal therapy. The patients were divided into two groups (n = 30) according to the rotary instrument used during root canal preparation (group A [HEDM] and group B [WOG]). Pain was evaluated after endodontic therapy at 8, 24, and 48 h intervals using the visual analog scale (VAS). Data obtained were analyzed using the chi-square test, independent t-test, MannWhitney U test, and Wilcoxon matched-pairs test. @*Results@#Statistically significant differences were observed between the two groups (P < 0.001) at 8, 24, and 48 h, with WOG exhibiting less pain than HEDM files. @*Conclusion@#Postoperative pain was lower in the WOG file system than in the HEDM file system after single-visit root canal therapy at 8, 24, and 48 h.
RESUMEN
AIM: We aimed to evaluate the effect of nonthermal atmospheric plasma (NTAP) on the bond strength of composite resin after using different tooth-whitening systems. METHODS: Eighty maxillary central incisors (n = 80) were divided into two groups based on the tooth-whitening procedure used - Group 1: bleaching (Pola Office, USA), Group 2: microabrasion (Opalustre, Australia). The samples were subdivided into four groups depending on the surface treatments - Group A: control (no surface treatment), Group B: plasma, Group C: antioxidant (sodium ascorbate), and Group D: buffering agent (sodium bicarbonate). After the surface treatments, the specimens were stored in artificial saliva for 24 h and composite resin was bonded to the labial surface of the teeth perpendicular to the long axis. The samples were then subjected to shear bond strength test under the universal testing machine. STATISTICAL ANALYSIS: The results received from shear bond strength analysis were subjected to statistical analysis using a two-way ANOVA test, independent t-test, and Tukey's multiple post hoc tests. The P value set was <0.05. RESULTS: The highest mean bond strength value was seen in Group 2B (NTAP treatment after microabrasion) followed by Group 1B (NTAP treatment after bleaching). Mean shear bond strength values have suggested a statistically significant difference between all the other groups (P < 0.05) except between Groups 1A, 2A and 1D, 2D. CONCLUSIONS: Within the limitations of the current in vitro study, bleaching and microabrasion followed by surface treatment using NTAP showed the highest bond strength than other groups.