RESUMO
Background: The adhesive bonding ability of composite resins makes it unnecessary to remove tooth structure for retention, prevention, and convenience. However, postoperative sensitivity after placing composite restoration has been a significant problem experienced by clinicians. Aim: The present randomized controlled trial was conducted to assess the role of dentin remineralization in the reduction of postoperative sensitivity after composite placement. Materials and Methods: Eighty participants with occlusal carious teeth were randomly allocated to one of the four study groups, each having 20 participants, and are as follows: Group A with test group, Group A with control group, Group B with test group, and Group B with control group. Postoperative sensitivity was assessed using the Visual Analog Scale (VAS) and the United States Public Health Service (USPHS) criteria at different time intervals such as baseline, 1 week, 1 month, and 3 months. Data were analyzed using the Kruskal-Wallis ANOVA test, Mann-Whitney U-test, and Wilcoxon matched-pair test. Results: All 80 participants were analyzed at the baseline, 1 week, 1 month, and the end of 3 months for the postoperative sensitivity using the VAS score and USPHS criteria. One restoration in Group A with control group reported mild sensitivity at the end of 1 week and one restoration in Group B with control group reported severe sensitivity at the end of 3 months, necessitating its replacement followed by root canal treatment. No relationship was reported between postoperative sensitivity and tooth type. There was no statistically significant difference in postoperative sensitivity in any of the treatment modalities. Conclusion: Class I restoration using self-etch or selective-etch as well as with or without zinc-carbonate hydroxyapatite is a viable and predictable solution for the reduction of postoperative sensitivity if all the aspects of restorative techniques are considered precisely.
RESUMO
CONTEXT BACKGROUND: The color stability of an esthetic material like composite resin may be hampered, due to the constant presence of oral microflora, saliva, and the frequent intake of food. However, as the oral cavity has a dynamic environment, the color stability of these restorative materials has been a challenge to dentistry. AIM: The aim of this study was to evaluate the effect of a saliva substitute (SS) on the color stability of three different nanocomposite restorative materials. MATERIALS AND METHODS: A total of 66 disc-shaped samples of test materials were prepared using a polycarbonate mold measuring 15 mm diameter and 2 mm height and were randomly assigned to three groups of 22 samples each based on the test material used: Group I - Estelite Sigma Quick, Group II - Solare sculpt, and Group III - Beautifil II LS. They were further divided into two subgroups A and B with 11 samples each based on the immersion solutions, namely distilled water (DW) and saliva substitute (SS), respectively. The samples were immersed for 30 days. Baseline and post immersion color analysis were done with a spectrophotometer. The CIE L*a*b* values were measured and CIE ΔE values obtained were tabulated. Data were analyzed using the two-way-ANOVA test and Tukey's multiple post hoc test. RESULTS: The mean color difference (ΔE) among the three different nanocomposite restorative materials ranged from 4.0 ± 0.26 to 10.62 ± 1.92. Group I showed the lowest color change (7.80 ± 0.55 and 4.00 ± 0.26), followed by Group III (8.59 ± 0.29 and 6.24 ± 0.66) and Group II (10.62 ± 1.92 and 6.85 ± 0.46) when immersed in SS and DW, respectively. CONCLUSION: All the specimens when immersed in SS showed greater discoloration than compared to the specimens immersed in DW. Group I showed greater resistance to color change compared to other groups.
RESUMO
BACKGROUND: An ideal dental repair material should possess certain important properties such as adequate adhesive ability, insolubility, dimensional stability, biocompatibility, and bioactivity. Newer materials claiming better performance are continuously being introduced in the market to optimize the care of dental patients. AIM: The aim of this study was to evaluate the shear bond strength of three different universal adhesives to OrthoMTA. MATERIALS AND METHODS: Sixty-four specimens of OrthoMTA measuring 4 mm internal diameter and 2 mm height were prepared and divided into two main groups. After 12 min, 32 samples were randomly selected and divided into four subgroups of eight samples each. Subgroup-I: Single Bond Universal, Subgroup-II: Prime-and-Bond NT, Subgroup-III: Palfique Universal bond, Subgroup-IV: Control. After the application of adhesives, the composite resin was applied using a cylindrical plastic matrix of 2 mm internal diameter and 2 mm height over OrthoMTA. This procedure was repeated 24 h after mixing an additional 32 samples, respectively. Shear bond strengths were measured using Universal testing machine and fractured specimen were examined under stereomicroscope. Data were statistically analyzed using a two-way ANOVA test and Tukey's multiple post hoc test. RESULTS: Statistical analysis revealed that subgroup-III exhibited higher bond strength at both 12 min and 24 h time intervals. It was also observed that most of the failures occurred cohesively within OrthoMTA. CONCLUSION: Shear bond strength was higher at 24 h than compared to 12 min. Subgroup-III exhibited higher bond strength than other subgroups.
RESUMO
AIM: The aim of this study is to compare the effects of conventional syringe, passive ultrasonic irrigation (PUI), and EndoIrrigator Plus on the amount of apically extruded debris. MATERIALS AND METHODS: Thirty extracted human mandibular premolars were selected and randomly assigned to three groups (n = 10). The root canals were irrigated with conventional syringe, PUI, and EndoIrrigator Plus. Sodium hypochlorite was used as an irrigant, and debris was collected in a previously described experimental model (Myers and Montgomery 1991). It was then stored in an incubator at 37°C for 10 days to evaporate the irrigant before weighing the dry debris. The mean weight of debris was assessed, one-way analysis of variance was used for comparison of values, and post hoc Tukey's test was used between groups (P = 0.05). RESULTS: The EndoIrrigator Plus group extruded significantly less debris than PUI and conventional syringe groups (P < 0.05). Furthermore, PUI group extruded significantly less debris than conventional syringe irrigation group (P < 0.05). CONCLUSIONS: 1. All the three irrigation systems were associated with apical extrusion of debris, 2. EndoIrrigator Plus system extruded significantly less debris than the PUI system and the conventional syringe irrigation system, 3. PUI system extruded significantly less debris than the conventional syringe irrigation system.
RESUMO
AIMS: To observe and study the effect of multiple autoclave sterilization cycles, on the surface of nickel-titanium (NiTi) files. MATERIALS AND METHODS: The file used for this study was the Mtwo file (VDW) and ProTaper (Dentsply). The apical 5 mm of the files were attached to a silicon wafer and subjected to autoclave cycles under standardized conditions. They were scanned with an AFM after 1, 5, and 10 cycles. The unsterilized files were used as control, before start of the study. Three vertical topographic parameters namely maximum height (MH), root mean square (RMS) of surface roughness, and arithmetic mean roughness (AMR)were measured with the atomic force microscope (AFM). Analysis of variance along with Tukey's test was used to test the differences. RESULTS: The vertical topographic parameters were higher for both the files, right after the first cycle, when compared with the control (P < 0.01). The surface roughness increased sharply for Mtwo when compared to ProTaper, though ProTaper had a rougher surface initially. CONCLUSIONS: The study confirmed that the irregularities present on the surface of the file became more prominent with multiple autoclave cycles, a fact that should be kept in mind during their reuse.
