The effect of smear layer removal on E. faecalis leakage and bond strength of four resin-based root canal sealers.
ABSTRACT: BACKGROUND:The aim of the study was to assess bacterial sealability and bonding ability of methacrylate-based Resilon (RS, SybronEndo), Endo Rez (ER, Ultradent Products Inc), and epoxy-based AH Plus (AH, Dentsply/DeTrey), MTA Fill Apex (MTAF, Angelus Soluções Odontológicas) root canal sealers, and the effect of the smear layer removal on the sealability. METHODS:One hundred thirty root segments were instrumented up to apical size #60 and rinsed with 2.5% NaOCl. Half of the roots were rinsed with 5ml 17% EDTA to remove the smear layer. All the roots were filled with AH, ER, MTAF sealers and gutta-percha, or RS with Resilon cones. After storage at 37°C for 7 days the samples were mounted into bacterial leakage assay for 50 days. Another 100 roots were instrumented and rinsed as described above, split longitudinally, cut into the cervical, middle and apical parts. The sealers were injected through the plastic mould on the dentin surface. After 7 days of incubation at 37°C, bond strength was tested using a notched-edge test fixture (Crosshead, Ultradent Products Inc.) and a universal testing machine (Lloyd Instruments). RESULTS:AH revealed the longest mean time for bacterial resistance by 29.4 and 36.8 days (with and without smear layer, respectively) followed by RS (15.1 and 24.7 days, respectively). The difference between materials was significant (p<0.001). Bond strength values ranged from 0.2± 0.1 to 3.5± 0.7 MPa and increased from the apical to the cervical third. In the apical third, AH showed the highest mean (SD) bond values 1.4 (0.4) MPa and 1.7 (0.6) MPa (with and without smear, respectively, followed by RS, 0.5 (0.1) MPa and 0.8 (0.1) MPa, respectively. The difference between materials was significant (p=0.001). CONCLUSION:The effect of the smear layer removal on the sealability was material-dependent.
Project description:Aim:The aim of this study was to evaluate the bond strength and thereafter analyze the mode of failure of the three sealers applied to smear free radicular dentine with final drying using 70% isopropyl alcohol and paper points. Materials and methods:A total of sixty root canals were prepared and then segregated into two groups (n = 30) as per the drying protocol, namely paper points or 70% isopropyl alcohol. Then, these roots were divided into three sub-groups (n = 10) with respective sealers and obturation materials, namely AH Plus and gutta-percha (AH/GP), EndoSequence BC and gutta-percha (EBC/GP), and MTA Fillapex and gutta-percha (MFP/GP). The roots were then sectioned from each third, and the push-out test was performed. Failure modes were examined under a stereomicroscope. Data were statistically analyzed by 2-way analysis of variance post hoc Tukey tests with a significant level of 5%. Results:Overall canals dried with isopropyl alcohol showed higher bond strength values than paper point (p < 0.05). The AH/GP group showed lower bond strength than EBC/GP (p < 0.05) but higher than MFP/GP (p < 0.05). The most frequent type of failure was cohesive in the AH/GP group and adhesive in the EBC/GP group whereas MFP/GP had almost similar adhesive and cohesive failures. Conclusion:Seventy percent isopropyl alcohol drying improved the bond strength of the root canal sealers with the dentinal tubules better than the ideal paper point drying. How to cite this article:Khurana N, Chourasia HR, et al. Effect of Drying Protocols on the Bond Strength of Bioceramic, MTA and Resin-based Sealer Obturated Teeth. Int J Clin Pediatr Dent 2019;12(1):33-36.
Project description:Bioactive endodontic sealers have been developed to improve the quality of root canal obturation. EndoSequence Bioceramic (BC) Sealer is amongst calcium silicate-based materials recently developed for permanent root canal filling. The objective of this study was to evaluate the bioactivity of BC Sealer and its micro push-out bond strength to dentin compared to AH-Plus (AH) sealer.To perform the micro push-out test, 24 root canals of mandibular premolars were instrumented and divided into two groups (n=12). Each root was cut into 4 slices and lumens of the canals were filled with the sealers and submitted to micro push-out test. Failure mode was assessed using scanning electron microscopy (SEM). Bioactivity of BC sealer was investigated with scanning electron microscopy/energy-dispersive X-ray (SEM/EDS) and X-ray diffraction (XRD). Bioactivity assessments were reported descriptively. Bond strength data were analyzed by parametric t-test (α=5%).In micro push-out test AH had higher bond strength mean values (16.29 MPa) than BC sealer (9.48 MPa) (P<0.05). Both groups had low amount of adhesive failure. SEM showed the presence of a mineral precipitate after 30 days and EDS analysis showed that those precipitates have high proportion of Ca. XRD showed peaks of crystalline phases of calcium carbonate compatible with the bioactivity.BC sealer showed indications of bioactivity and lower bond strength to dentine compared to AH.
Project description:This study aimed to compare the effect of conventional irrigation (CI) and passive ultrasonic irrigation (PUI) with 17% EDTA and QMiX on the maximum depth and percentage of sealer penetration into the dentinal tubules by confocal laser scanning microscopy (CLSM) and to describe the cleaning of root canal walls by scanning electron microscopy (SEM). Eighty single-rooted human mandibular premolars were instrumented and randomly assigned to four groups (n?=?20): EDTA?+?CI, QMiX + CI, EDTA?+?PUI, and QMiX + PUI. Ten samples from each group were examined by SEM (2,000×) and the remaining 40 roots were filled with a single gutta-percha cone and AH Plus sealer mixed with 0.1% rhodamine B for analysis by CLSM (10×). Images were assessed at distances of 2?mm (apical), 5?mm (middle), and 8?mm (coronal) from the apex with the Leica Application Suite V4.10 software. The EDTA?+?PUI and QMiX + PUI protocols presented higher rates of debris/smear layer removal in the apical and middle thirds. The PUI was superior to CI in the maximum depth of sealer penetration at the middle third. The QMiX + PUI group had a higher percentage of sealer penetration at the apical third. The PUI and QMiX protocol improved debris/smear layer removal and tubular dentin sealer penetration.
Project description:The aim of the present in vitro study was to evaluate the cytotoxicity of different sealers including GuttaFlow Bioseal, GuttaFlow 2, AH-Plus and MTA Fillapex on L929 murine fibroblasts.Samples of GuttaFlow Bioseal, GuttaFlow 2, AH-Plus and MTA Fillapex were fabricated in Teflon disks of 5 mm diameter and 3 mm thickness. L929 fibroblasts were exposed to the extracts of these materials for 3, 24, 72 and 168 h at 37°C with 5% CO2. Cell viability was evaluated by the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Apoptosis was evaluated by the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assay. The data were analysed by ANOVA.GuttaFlow Bioseal was nontoxic at all experimental time points (P>0.05), whereas MTA Fillapex and AH-Plus were toxic (P<0.001). At 7 days, there were more viable cells in the GuttaFlow 2 group than in the control group, and MTA Fillapex was more cytotoxic than AH-Plus. There were more apoptotic cells in the MTA Fillapex and AH-Plus groups than in the other groups at 3 h (P<0.001).GuttaFlow sealers are less cytotoxic than MTA Fillapex and AH-Plus. At all experimental time points, there was no significant difference in the cell viability between the GuttaFlow Bioseal group and the control group.
Project description:Hinokitiol displays potent antimicrobial activity. It has been used in toothpaste and oral-care gel to improve the oral lichen planus and reduce halitosis. The aim of this study was to evaluate the antimicrobial activity of 3 different dental root canal sealers with hinokitiol (sealers+H) and their physical and biological effects. AH Plus (epoxy amine resin-based, AH), Apexit Plus (calcium-hydroxide-based, AP), and Canals (zinc-oxide-eugenol-based, CA), were used in this study. The original AH and CA exhibited strong anti-methicillin-resistant Staphylococcus aureus (anti-MRSA) activity, but AP did not. The setting time, working time, flowability, film thickness, and solubility of each sealer+0.2%H complied with ISO 6876:2001. CA+0.2%H exhibited high cytotoxicity, but the others sealers+0.2%H did not. Because hinokitiol combined with Zn2+ in CA creates a synergistic effect. The physical tests of AP+0.5%-1%H complied with ISO 6876:2001, improved antimicrobial activity, inhibited inflammation genes cyclooxygenase-2 (COX-2) and hypoxia-inducible factor-1? (HIF-1?) mRNA in MG-63 cells and human gingival fibroblasts (HGF), and down-regulated lysyl oxidase (LOX) mRNA of HGF. In summary, AH and CA demonstrated strong antimicrobial activity, but AP did not. Application of hinokitiol increases AH anti-MRSA activity should less than 0.2% for keep well flowability. AP+0.5%-1% hinokitiol exhibited strong physical, antibacterial, and anti-inflammation potentials, and inhibited S. aureus abscess formation. Applying an appreciable proportion of hinokitiol to epoxy-amine-resin-based and calcium-hydroxide-based root canal sealers is warranted, but the enhanced cytotoxicity and synergistic effect must be considered.
Project description:Calcium silicate-based bioactive glass has received significant attention for use in various biomedical applications due to its excellent bioactivity and biocompatibility. However, the bioactivity of calcium silicate nanoparticle-incorporated bioactive dental sealer is not much explored. Herein, three commercially available bioactive root canal sealers (Endoseal MTA (EDS), Well-Root ST (WST), and Nishika Canal Sealer BG (NBG)) were compared with a resin-based control sealer (AH Plus (AHP)) in terms of physical, chemical, and biological properties. EDS and NBG showed 200 to 400 nm and 100 to 200 nm nanoparticle incorporation in the SEM image, respectively, and WST and NBG showed mineral deposition in Hank's balanced salt solution after 28 days. The flowability and film thickness of all products met the ISO 3107 standard. Water contact angle, linear dimensional changes, and calcium and silicate ion release were significantly different among groups. All bioactive root canal sealers released calcium ions, while NBG released ~10 times more silicon ions than the other bioactive root canal sealers. Under the cytocompatible extraction range, NBG showed prominent cytocompatibility, osteogenecity, and angiogenecity compared to other sealers in vitro. These results indicate that calcium silicate nanoparticle incorporation in dental sealers could be a potential strategy for dental periapical tissue regeneration.
Project description:The flowability of a root canal sealer is clinically important because it improves the penetration of the sealer into the complex root canal system. The purpose of this study was to compare the flowabilities of four root canal sealers, measured using the simple press method (ISO 6876), and their viscosities, measured using a strain-controlled rheometer. A newly developed, calcium phosphate-based root canal sealer (Capseal) and three commercial root canal sealers (AH Plus, Sealapex and Pulp Canal Sealer EWT) were used in this study. The flowabilities of the four root canal sealers were measured using the simple press method (n=5) and their viscosities were measured using a strain-controlled rheometer (n=5). The correlation between these two values was statistically analysed using Spearman's correlation test. The flow diameters and the viscosities of the root canal sealers were strongly negatively correlated (ρ=-0.8618). The viscosity of Pulp Canal Sealer EWT was the lowest and increased in the following order: AH Plus<Sealapex<Capseal (P<0.05). All of the tested root canal sealers showed characteristic time- and temperature-dependent changes in their rheological properties. The viscosities measured using the strain-controlled rheometer were more precise than the flowabilities measured using the simple press method, suggesting that the rheometer can accurately measure the rheological properties of root canal sealers.
Project description:Aim:This study aimed to evaluate and compare the antimicrobial efficacy of root canal sealers of different bases when mixed with herbal extracts. Materials and methods:An evaluation of three sealers (Endomethasone, AH plus, Apexit plus) mixed with three herbal extracts [Emblica officinalis (Amla), Myristica fragrans (Nutmeg) and Salvadora persica (Miswak)] was done against nine strains of bacteria at various time intervals using the agar diffusion test. Moreover, measurement of the mean zones of inhibition was done. Results:The largest zones of bacterial growth inhibition were observed with Endomethasone mixed with Myristica fragrans (Nutmeg) followed in the descending order by AH plus mixed with Salvadora persica (Miswak) and Apexit plus mixed with Salvadora persica (Miswak) respectively. The differences between zones of inhibition among different groups were found to be statistically significant. Conclusion:Zinc-oxide-eugenol-based sealer (Endomethasone) mixed with herbal extracts produced the largest inhibitory zones followed in the descending order by resin-based sealer (AH plus) and calcium-hydroxide-based sealer (Apexit plus), respectively. Clinical significance:Herbal plants such as [Emblica officinalis (Amla), Myristica fragrans (Nutmeg) and Salvadora persica (Miswak)] are rich sources of bioactive compounds that possess antimicrobial properties. Mixing their extracts with endodontic sealers can produce additive antimicrobial effect against microbes found in inflamed pulp. How to cite this article:Devi MT, Saha S, Tripathi AM, et al. Evaluation of the Antimicrobial Efficacy of Herbal Extracts Added to Root Canal Sealers of Different Bases: An In Vitro Study. Int J Clin Pediatr Dent 2019;12(5):398-404.
Project description:OBJECTIVE:This study was conducted to reveal potential metabolic differences of dairy cows fed corn stover (CS) and rice straw (RS) instead of alfalfa hay (AH) as main forage source. METHODS:Thirty multiparous mid-late lactation Holstein dairy cows were selected and randomly assigned to three diets, AH, CS, or RS (n = 10). After 13 weeks of the feeding trial, coccygeal arterial and superficial epigastric venous plasma samples were collected before morning feeding for gas chromatography time-of-flight/mass spectrometry analyses. RESULTS:In the artery, 8 and 13 metabolites were detected as differential metabolites between AH and CS, and between AH and RS, respectively. The relative abundance of phenylpropanoate (log2fold change [FC]) = 1.30, 1.09), panthenol (log2FC = 2.36, 2.20), threitol (log2FC = 1.00, 1.07), and 3,7,12-trihydroxycoprostane (log2FC = 0.79, 0.78) were greater in both CS and RS than in AH, and tyrosine (log2FC = -0.32), phenylalanine (log2FC = -0.30), and pyruvic acid (log2FC = -0.30) were lower in RS than in AH. In the vein, 1 and 7 metabolites were detected as differential metabolites between AH and CS, and between AH and RS, respectively. By comparing AH and RS, we found that metabolic pathways of phenylalanine, tyrosine, and tryptophan biosynthesis and phenylalanine metabolism were enriched by integrative artery and vein analysis. Furthermore, AH and RS, arterial phenylpropanoate and 4-hydroxyproline were positively, and phenylalanine was negatively correlated with milk urea nitrogen. Finally, in AH and CS, arterial panthenol was negatively correlated with feed efficiency. CONCLUSION:Arterial metabolic profiles changed more than those in the veins from animals on three forage diets, differing in amino acids. We found that phenylalanine, tyrosine, and tryptophan biosynthesis and phenylalanine metabolism were restricted when cows were fed low-quality cereal straw diets.
Project description:The solubility, pH, electrical conductivity, and radiopacity of AH Plus and MTA FillApex were evaluated. In addition, the surfaces morphologies of the sealers were analyzed by using scanning electron microscopy. For pH test, the samples were immersed in distilled water at different periods of time. The same solution was used for electrical conductivity measurement. The solubility and radiopacity were evaluated according to ANSI/ADA. Statistical analyses were carried out at 5% level of significance. MTA FillApex presented higher mean value for solubility and electrical conductivity. No significant difference was observed in the mean values for pH reading. AH Plus presented higher radiopacity mean values. MTA FillApex presented an external surface with porosities and a wide range of sizes. In conclusion, the materials fulfill the ANSI/ADA requirements when considering the radiopacity and solubility. AH Plus revealed a compact and homogeneous surface with more regular aspects and equal particle sizes.