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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.
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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.
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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.
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AIM: The aim of this study was to evaluate the effect of nonthermal atmospheric plasma (NTAP) on the bond strength of epoxy resin-based and bioceramic root canal sealers. MATERIALS AND METHODS: Freshly extracted forty (n = 40) single-rooted mandibular premolar teeth were divided into four groups (n = 10) based on the sealer used and NTAP application - Group 1: Epoxy resin-based sealer (AH Plus) without NTAP application, Group 2: Epoxy resin-based sealer (AH Plus) with NTAP application for 30 s, Group 3: Bioceramic sealer (BioRoot RCS) without NTAP application, and Group 4: Bioceramic sealer (BioRoot RCS) with NTAP application for 30 s. After NTAP application in Groups 2 and 4, all the samples were obturated using sealers according to their grouping protocols. Two-millimeter slices were obtained from each sample using hard tissue microtome, which were subjected to push-out bond strength (PBS) under the universal testing machine. Data were subjected to statistical analysis using one-way analysis of variance followed by the Post hoc tukey test. The level of statistical significance was set at P < 0.05. RESULTS: The PBS values were observed to be significantly higher in bioceramic sealer with NTAP application (Group 4) followed by epoxy resin-based sealer with NTAP application (Group 2). CONCLUSION: NTAP application enhanced the PBS of bioceramic (BioRoot RCS) and epoxy resin-based (AH Plus) sealers compared to their control groups.
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BACKGROUND: To maintain the integrity of the interface between root canal filling and radicular dentin an ideal endodontic biomaterial should have good adhesion. This study was aimed to evaluate the bond strength and tubular penetration of modified bioceramic materials by indirect ultrasonic activation. MATERIALS AND METHODS: In the present in vitro experimental study, 120 coronal root slices of 2 mm were prepared from mandibular premolars and randomly divided into six groups (n = 20) in accordance to placement techniques: Group I: Nano Biodentine-manual, Group II: CaCl2 modified ProRootMTA-manual (MM), Group III: Biodentine-manual, Group IV: Nano Biodentine: Ultrasonic, Group V: CaCl2 modified ProRootMTA-ultrasonic, and Group VI: Biodentine-ultrasonic (BDU). The samples were kept in humidifier for 4 days at 37°C and push out bond strength, sealer penetration were evaluated using an universal testing machine and confocal laser scanning microscope respectively. Data were subjected to statistical analysis using SPSS software by using One-way ANOVA for overall significance and Tukey's multiple post hoc test for intergroup comparison (P < 0.05). RESULTS: Highest push out bond strength and greater tubular penetration were observed with Group VI (BDU), while the lowest bond strength and tubular penetration were associated with Group II (MM). CONCLUSION: Within the limitations of current study it was observed that Biodentine with indirect ultrasonic activation has resulted in highest pushout bond strength among all the study groups.
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AIM: The purpose of this study was to evaluate the effect of 17% ethylenediaminetetraacetic acid (EDTA) and 0.2% chitosan on pushout bond strength of biodentine and ProRoot mineral trioxide aggregate (MTA). MATERIALS AND METHODS: Midroot dentin of single-rooted human canine teeth were sectioned into 2-mm-thick slices horizontally (n = 60). The canal space of each dentin slice was enlarged with a 1.3-mm-diameter diamond bur. The samples were divided into two groups (n = 30) based on the type of perforation repair material placed, i.e., Biodentine and ProRoot MTA. The samples were wrapped in wet gauge for 10 min, and based on the type of chelating agent used for removal of smear layer, each group is further divided into three subgroups (n = 10), to be immersed into saline (control), 17% EDTA and 0.2% chitosan for 30 min, and a wet cotton pellet was placed over each test material. After 48 h of incubation, the dislodgement resistance of the samples was measured using a universal testing machine. STATISTICAL ANALYSIS: Data were analyzed using one-way analysis of variance and post hoc Tukey tests. The level of statistical significance was set at 0.05. RESULTS: Biodentine showed significantly higher pushout bond strength than ProRoot MTA. Biodentine and ProRoot MTA lost strength when exposed to 0.2% chitosan. CONCLUSION: Biodentine showed considerable performance as a perforation repair material than ProRoot MTA even after being exposed to various endodontic chelating agents.
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AIM: The study was aimed to evaluate the effect of 5.25% NaOCl and 17% ethylenediaminetetraacetic acid (EDTA) Solutions on Surface Topography of ESX, TruShape, and ProTaper Gold nickel-titanium (NiTi) Rotary Instruments using Atomic Force Microscope (AFM). MATERIALS AND METHODOLOGY: A total of 27 each of three commercially available brands of endodontic NiTi instruments were analyzed, which were divided into three groups as follows: Group I: ESX (Brasseler, USA) Group II: Tru shape (Dentsply Tulsa, USA) Group III: Pro Taper Gold (Dentsply Tulsa, USA). These files were further divided into three subgroups containing nine files each, no immersion, immersion in 5.25% NaOCl for 5 min, and immersion in 17% EDTA for 5 min. Surface areas along 3 mm sections at the tip of the files (perfect squares of 10 µm × 10 µm) were analyzed using AFM operating in contact mode under ambient conditions. STATISTICAL ANALYSIS: Data were analyzed using two-way ANOVA and pairwise comparison of three main groups with respect to Ra and RMS by Tukey's multiple posthoc procedures. RESULTS: Three-dimensional AFM images of the surface of all the rotary NiTi instruments, including new and those immersed in 5.25% NaOCl and 17% EDTA solutions, revealed topographic irregularities at the nanometric scale. Ra and RMS values of instruments treated with 5.25% NaOCl and 17% EDTA solutions were statistically higher than that of the new ones (P < 0.05). CONCLUSION: Using AFM for analysis indicated that short-term contact between 5.25% NaOCl and 17% EDTA solutions and NiTi instruments caused alterations in the topography of instruments.
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INTRODUCTION: The aim of this study was to investigate the microhardness and microstructural features of newer tricalcium silicate materials: TheraCal LC, mineral trioxide aggregate (MTA), biodentine (BD), and Endosequence Root Repair Material (ERRM) putty, after exposure to acidic environments in comparison with distilled water. MATERIALS AND METHODS: A total of 80 extracted single-rooted premolars were collected. All the selected specimens were sectioned vertically, and cavities were prepared on the root surface. Specimens were divided into four groups of 20 each, i.e., Group 1: (n = 15) MTA (ProRoot, Dentsply Tulsa Dental, Tulsa, OK, USA), Group 2: (n = 15) BD (Septodont, France), Group 3: (n = 15) ERRM putty (Brasseler, USA), and Group 4: (n = 15) TheraCal LC (Bisco Inc Schaumburg). Materials were placed into prepared cavities. About 10 specimens per each group were exposed to butyric acid buffered at a pH level of 5.5 for 7 days at 37c, and 10 specimens from each group were exposed to distilled water serving as a control group. The surface microhardness was measured after exposure to either acid or distilled water. Scanning electron microscope was used to observe the internal microstructure morphology. Two-way analysis of variance was applied to evaluate the Knoop microhardness value (KHN). RESULTS: Results showed that the microhardness values of the materials were significantly higher in the neutral environment of butyric acid at pH 7.4 when compared to those in the acidic condition of pH 5.4 for all groups (P < 0.001). TheraCal LC had higher microhardness values than BD, MTA, ERRM putty at 5.5 pH levels (P < 0.001). CONCLUSION: The microhardness values of TheraCal LC, BD, ERRM Putty, and MTA were reduced in an acidic environment, which resulted in these materials having more porous and less crystalline microstructures. TheraCal LC seems the most suitable material for application to an area of inflammation where a low pH value may exist.
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AIM: The purpose of this study was to evaluate the clinical performance of Ketac Nano (Ketac™ N100), RMGIC (Fuji Filling™ LC), and Giomer (Beautifil® II) in noncarious cervical lesions (NCCLs). MATERIALS AND METHODS: One operator restored 120 NCCLs in 20 subjects, with at least two lesions restored with one of the restorative materials: RMGIC (control group), Giomer and Ketac Nano (experimental groups). Two observers evaluated retention, marginal discoloration, marginal adaptation, color match, surface roughness, and postoperative sensitivity using modified USPHS criteria at baseline, 6, and 12 months. STUDY DESIGN: Double-blinded randomized clinical trial (RCT). STATISTICAL ANALYSIS: Kruskal-Wallis test, Mann-Whitney U-test, Wilcoxon matched-pairs test. RESULTS: There was statistically significant difference observed between Giomer, Ketac Nano and RMGIC after 12 months (P < 0.05). There was a significant decrease in retention rates for Giomer (P = 0.0050), increased marginal discoloration and color mismatch for Ketac Nano (P = 0.0025, P = 0.0053), increased surface roughness and color mismatch with RMGIC (P = 0.0022, P = 0.0077) from baseline to 12 months. CONCLUSION: Within the limitations of this RCT of 12 months, Ketac Nano and RMGIC restorations were better retained in NCCLs while superior color match and surface finish were observed with Giomer restorations.
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AIM: The purpose of this study was to evaluate the sealing ability of mineral trioxide aggregate (MTA) and EndoSequence with chitosan and carboxymethyl chitosan (CMC) as retrograde smear layer removing agents using scanning electron microscopy (SEM). MATERIALS AND METHODS: Forty human single rooted teeth were taken. Crowns were decoronated and canals were obturated. Apically roots were resected and retrograde cavities were done. Based on the type of retrograde material placed and the type of smear layer removal agent used for retrograde cavities, they were divided into four groups (N = 10): Group I chitosan with EndoSequence, group II chitosan with MTA, group III CMC with EndoSequence, and Group IV CMC with MTA. All the samples were longitudinally sectioned, and the SEM analysis was done for marginal adaptation. STATISTICAL ANALYSIS: Kruskal-Wallis and Mann-Witney analysis tests. RESULTS: SEM images showed the presence of less gaps in group III, i.e., CMC with EndoSequence when compared to other groups with statistically significant difference. CONCLUSION: Within the limited scope of this study, it was concluded that EndoSequence as retrograde material showed better marginal sealing ability.
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AIM: To evaluate the cytotoxicity of three root repair materials, mineral trioxide aggregate (MTA), Endosequence Root Repair Material and Biodentine in human periodontal ligament fibroblasts. MATERIALS AND METHODS: Periodontal ligament fibroblasts were cultured from healthy premolar extracted for orthodontic purpose. Cells in the third passage were used in the study. The cultured fibroblast cells were placed in contact with root repair materials: (a) Biodentine, (b) MTA, (c) Endosequence, (d) control. The effects of these three materials on the viability of Periodontal ligament (PDL) fibroblasts were determined by trypan blue dye assay after 24 hours and 48-hour time period. Cell viability was determined using inverted phase contrast microscope. STATISTICAL ANALYSIS: Cell viability was compared for all the experimental groups with Wilcoxons matched pair test. RESULTS: At the 24-hour examination period, all the materials showed increased cell viability. At 48-hour time period, there is slight decrease in cell viability. Mineral trioxide aggregate showed statistically significant increase in the cell viability when compared to other root repair materials. CONCLUSION: Mineral trioxide aggregate was shown to be less toxic to periodontal ligament fibroblasts than Endosequence Root Repair Material and Biodentine.
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AIM: To analyze the sustained release of intracanal medicaments with or without a carrier and testing their antimicrobial efficacy in root canal against Candida albicans and Enterococcus faecalis. MATERIALS AND METHODS: A total of 80 single-rooted anterior teeth were selected, root canal preparation was done, and teeth were divided into two halves and contaminated with C. albicans and E. faecalis, which were further divided into four test groups each according to intracanal medicaments used. Chitosan was used as vehicle for triple antibiotic paste (TAP) and calcium hydroxide and antimicrobial assessment was performed on second and seventh day. Dentine samples were collected after each. RESULTS: All four medicaments used in this study showed antifungal and antibacterial activity. Group II (TAP + chitosan) and Group III (Ca(OH)2 + chitosan) had the higher antifungal and antibacterial activity compared with two other groups. CONCLUSION: Combination of TAP + chitosan and Ca(OH)2 + chitosan produced better results compared with the combination of medicaments with saline.
