A comparative histological study of the effect of TheraCal LC and biodentine on direct pulp capping in rabbits: an experimental study.

OBJECTIVES: This study histologically compared the effect of TheraCal LC and biodentine on direct pulp capping using a rabbit model. MATERIALS AND METHODS: A direct pulp capping procedure was performed on 40 mandibular central incisors of 20 healthy, male New Zealand white rabbits. TheraCal LC and biodentine were applied to exposed pulp and 10 randomly selected rabbits were euthanized after the first and second week. Incisors were extracted and prepared for histological processing and examination to check the dentine bridge thickness, continuity, and extent of pulp inflammation. A blinded data analysis was performed, and groups were compared using a Wilcoxon signed-rank test while changes across time within each group were assessed using the Mann-Whitney U test. RESULTS: When comparing the dentine bridge thickness, biodentine showed a significantly thicker dentine bridge in the first and second week (mean 28.16 µm, 33.66 µm), while TheraCal LC showed a dentine bridge in the second week only (mean 15.93 µm). Regarding dentine bridge continuity, biodentine showed a significantly better dentine bridge in the first week. Additionally, there was no difference in the second week. Furthermore, there was no statistically significant difference between each of the materials regarding the extent of inflammation. CONCLUSIONS: Biodentine in vivo showed better results concerning thickness and continuity of the dentine bridge after direct pulp capping in rabbit incisors. Both biodentine and TheraCal LC had a similar inflammatory effect on the pulp. CLINICAL RELEVANCE: Biodentine is more successful as a direct pulp capping material compared to TheraCal LC.

Evaluation of the chemical, physical, and biological properties of a newly developed bioceramic cement derived from cockle shells: an in vitro study.

BACKGROUND: Tricalcium silicate is the main component of commercial bioceramic cements that are widely used in endodontic treatment. Calcium carbonate, which is manufactured from limestone, is one of the substrates of tricalcium silicate. To avoid the environmental impact of mining, calcium carbonate can be obtained from biological sources, such as shelled mollusks, one of which is cockle shell. The aim of this study was to evaluate and compare the chemical, physical, and biological properties of a newly developed bioceramic cement derived from cockle shell (BioCement) with those of a commercial tricalcium silicate cement (Biodentine). METHODS: BioCement was prepared from cockle shells and rice husk ash and its chemical composition was determined by X-ray diffraction and X-ray fluorescence spectroscopy. The physical properties were evaluated following the International Organization for Standardization (ISO) 9917-1;2007 and 6876;2012. The pH was tested after 3 h to 8 weeks. The biological properties were assessed using extraction medium from BioCement and Biodentine on human dental pulp cells (hDPCs) in vitro. The 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5[(phenylamino)carbonyl]-2 H-tetrazolium hydroxide assay was used to evaluate cell cytotoxicity following ISO 10993-5;2009. Cell migration was examined using a wound healing assay. Alizarin red staining was performed to detect osteogenic differentiation. The data were tested for a normal distribution. Once confirmed, the physical properties and pH data were analyzed using the independent t-test, and the biological property data were analyzed using one way ANOVA and Tukey's multiple comparisons test at a 5% significance level. RESULTS: The main components of BioCement and Biodentine were calcium and silicon. BioCement's and Biodentine's setting time and compressive strength were not different. The radiopacity of BioCement and Biodentine was 5.00 and 3.92 mmAl, respectively (p < 0.05). BioCement's solubility was significantly higher than Biodentine. Both materials exhibited alkalinity (pH ranged from 9 to 12) and demonstrated > 90% cell viability with cell proliferation. The highest mineralization was found in the BioCement group at 7 days (p < 0.05). CONCLUSIONS: BioCement exhibited acceptable chemical and physical properties and was biocompatible to human dental pulp cells. BioCement promotes pulp cell migration and osteogenic differentiation.

Antibiofilm potential over time of a tricalcium silicate material and its association with sodium diclofenac.

OBJECTIVES: The objectives of this study are to investigate, over time, the antimicrobial activity against polymicrobial biofilms and ability to inhibit biofilm formation, of Biodentine (BD) alone and with 5% and 10% sodium diclofenac (DC). MATERIAL AND METHODS: The antimicrobial activity of BD alone and modified with 5% and 10% DC against polymicrobial biofilm growth in dentin was determined by a modified direct contact test. The study groups were (1) BD; (2) BD + 5% DC; and (3) BD + 10% DC. The viability of microorganisms after 1 and 4 weeks was quantified by means of an ATP assay and flow cytometry. The antibiofilm efficacy of the materials, preventing polymicrobial biofilm formation over time, was assessed by confocal laser scanning microscopy (CLSM). RESULTS: The results obtained with both the ATP test and flow cytometry showed that BD alone and with 5% and 10% DC exerted antibiofilm activity with respect to the control, in the two evaluated times (p < 0.001). Comparison between groups showed a tendency of increased antimicrobial effect, both over time and depending on the DC concentration. These results coincide with those obtained in CLSM analysis, where efficacy increased with time and DC concentration. CONCLUSIONS AND CLINICAL RELEVANCE: Biodentine, over time, showed antimicrobial and antibiofilm efficacy on polymicrobial biofilms. The addition of 5% and 10% DC to BD enhanced this effect, in a concentration- and time-dependent manner.

Outcomes of root canal therapy or full pulpotomy using two endodontic biomaterials in mature permanent teeth: a randomized controlled trial.

OBJECTIVE: The concept of minimally invasive endodontics recommends less-invasive vital pulp therapy (VPT) modalities over more aggressive traditional endodontic approaches in mature permanent teeth with carious pulp exposure, including irreversible pulpitis (IP) cases. Consequently, VPT needs to be compared with root canal therapy (RCT) in terms of treatment outcomes. This randomized clinical trial compares the results of full pulpotomy using two calcium-silicate cements, i.e., mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM) cement, with RCT in mature permanent teeth. MATERIALS AND METHODS: A total of 157 carious pulp exposure cases in two academic centers with/without established IP were selected/included/randomly appointed to three study arms; (i) RCT (n = 51) as the reference treatment, (ii) pulpotomy with ProRoot MTA (PMTA; n = 55), and (iii) pulpotomy with CEM cement (PCEM; n = 51) as two alternative VPT treatments. Two-year clinical/radiographic results were the outcomes of interest. Data were statistically analyzed through the analysis of variance, chi-square, Fisher exact test, and Kruskal-Wallis. RESULTS: At 2-year recall, 147 teeth were examined (6.4% dropout). All molars, except for one, were clinically functional/symptom-free, and there was no statistical difference between the three study arms (p = 0.653). The radiographic success rates in RCT, PMTA, and PCEM arms were 98%, 100%, and 97.9%, respectively, without statistically significant differences (p = 0.544). CONCLUSION: In the management of mature permanent teeth with/without established IP, all experimental groups exhibited equivalent/comparable results. CLINICAL RELEVANCE: Simple VPT using MTA/CEM can be suggested/recommended as a viable advantageous alternative to RCT for the management of carious pulp exposures with/without sign/symptoms of IP.

Long-term evaluation of early-enamel lesions treated with novel experimental tricalcium silicate paste: A 2-year randomized clinical trial.

OBJECTIVE: The aim of the current study is to evaluate the remineralization potential of experimental tricalcium silicate (TCS) paste in comparison with more popular remineralizing agents like silver diamine fluoride potassium iodide (SDF-KI) and casein phosphopeptide amorphous calcium phosphate (CPP-ACP) on early enamel lesions. MATERIALS AND METHODS: Forty-five patients in the age range of 15-50 years had early enamel lesions on the buccal surface of molar teeth. The patients were randomly divided into three treatment groups (SDF-KI, CPP-ACP, and TCS group) with 15 patients per group. Lesions were evaluated clinically by DIAGNOdent pen immediately and after 3,6,12, and 24 months of treatment. RESULTS: The study was completed with 45 patients and 92 teeth. Twice-daily application of CPP-ACP and TCS paste showed a significant remineralization effect on early enamel lesions after 24 months (p < 0.001). Also, annual application of SDF-KI showed a significant remineralization effect after 24 months (p < 0.001). There was a significant difference between (SDF-KI and CPP-ACP) and (SDF-KI and TCS) at the different follow-up periods 3,6,12, and 24 months (p < 0.001). Meanwhile, there was no significant difference between CPP-ACP and TCS at the mentioned follow-up periods (p > 0.05). CONCLUSION: TCS showed potential remineralization for early enamel lesions. CLINICAL RELEVANCE: Experimental TCS is a promising remineralizing agent for management of early enamel lesions.

Compressive strength, surface roughness, and surface microhardness of principle tricalcium silicate-based endodontic cements after universal adhesive application.

Aims and Background: It was aimed to evaluate compressive strength (CS), surface roughness, and microhardness of mineral trioxide aggregate (ProRoot MTA) and Biodentine (BD) after adhesive application. Materials and Methods: Tests was carried out according to international ISO standard. ProRoot MTA and BD were prepared in Teflon molds according to manufacturer's instructions: n = 210 for CS; n = 210 for microhardness. Samples were incubated for 7 days at 37°C in 100% humidity. Surfaces were smoothed with up to 2000 grits of silicon-carbide sandpaper on abrasive device at 150 rpm, randomly divided into seven groups (n = 15). Clearfil Universal Bond, All Bond Universal, and Single Bond Universal (SBU) were applied in both total-etch and self-etch (SE) modes. Adhesives were applied according to manufacturers' recommendations (no adhesive used in control). CS was performed at speed of 1 mm/min, microhardness at 100 gr for 15 s. The surface roughness of the samples was analyzed with atomic force microscopy. Two-way analysis of variance and post hoc Tukey tests were used for the evaluation of the data. Results: Man CS and microhardness values between ProRoot MTA and BD were as follows: 24.9 N, 72.6 HV; 59.8 N, 59.0 HV, respectively. In CS, BD was higher than ProRoot MTA (P < 0.05). In other comparisons except for SBU SE group (P < 0.05), BD and ProRoot MTA showed similar results (P > 0.05). However, ProRoot MTA was found higher than BD regarding microhardness (P < 0.05). As a result of the adhesive application in both BD and ProRoot MTA groups, a decrease in surface roughness was observed compared to the control group. Conclusion: BD exhibited better results than ProRoot MTA regarding CS. However, ProRoot MTA was found to be more successful than BD in terms of microhardness. BD and ProRoot MTA showed similar physical properties in terms of surface roughness. To improve regenerative procedures, besides the selection of bioceramic cements, the interaction between cements and materials applied during coronal restoration should be considered.

Biological parameters, discolouration and radiopacity of calcium silicate-based materials in a simulated model of partial pulpotomy.

AIM: To analyse the discolouration, radiopacity, pH and calcium ion release of Biodentine (BD), Bio-C repair (BCR) and Bio-C temp (BCT), as well as their biological effects on human dental pulp cells (hDPCs). METHODOLOGY: Sixty-four extracted bovine incisors were prepared to simulate crown fractures with pulp exposure and open root apex. The roots were filled using a mixture of agar and blood (control), and BD, BCR or BCT were placed over this mixture. Colour assessment analyses of the samples were performed before and immediately after material insertion and repeated at 30 and 90 days, using a spectrophotometer. The colour change of each specimen was evaluated at the crown and calculated based on the CIELab colour space. Digital radiographs were acquired for radiopacity analysis. hDPCs were placed in contact with different dilutions of culture media previously exposed to such materials and tested for cell viability using the MTT assay. The pH and calcium ion release of all materials were measured after 24 h; the data were assessed using one-way analysis of variance (ANOVA). Cell viability was analysed by two-way ANOVA. Differences in colour parameters and wound-healing data were assessed by two-way repeated measures ANOVA (α = 0.05). Tukey's and Dunnett's tests were used to compare the experimental groups with the control group. RESULTS: BCR had grater radiopacity and smaller colour alteration (ΔEab/ΔE00) than the other materials tested (p < .005; p < .001). No significant differences in pH were found amongst the tested materials (p > .05). BCT was associated with the largest release of calcium ions (p < .0001). BD had cell viability similar to that of the control at the lowest dilutions, and BCR was similar to that of the control, regardless of the dilution tested (p > .05). BCT had a lower percentage of viability than that of the control at all tested dilutions (p < .0001). Cell migration rates in BD and BCR were similar to those in the control group after 24 h and 48 h (p > .05), whilst BCT had larger voids than the control in both periods (p < .0001). CONCLUSIONS: BCR, BCT and BD were associated with tooth discolouration. BCR had the lowest staining values, the highest radiopacity and viability greater than 80% hDPCs.

Root-end microsurgery using a premixed tricalcium silicate putty as root-end filling material: a prospective study.

OBJECTIVES: The purpose of this study was to assess the clinical and radiographic outcome of root-end microsurgery using a premixed fast-set calcium silicate putty as root-end filling material in human teeth. MATERIALS AND METHODS: This study included 50 teeth in 35 patients, whose ages ranged from 16 to 69 years. After clinical and radiographic examination, informed consent was obtained and one resident performed all surgical procedures using an endodontic microsurgical approach. A tricalcium silicate-based putty (TotalFil FS putty, FKG Dentair, La Chaux-de-Fonds, Switzerland) was used as a root-end filling material. Patients were recalled and treated teeth were examined clinically and radiographically at 3 months, 6 months, and 1 year postoperatively. The outcome was determined based on clinical and radiographic results. Radiographic healing was classified into 4 categories: complete, incomplete, uncertain, and unsatisfactory. Analysis of predictors was performed using the Pearson chi-square or Fisher's exact test. RESULTS: At the time of surgery, 3 teeth were diagnosed with cracks and were excluded from the study. The recall rates were 85% at 3 months, 100% at 6 months, and 95% at 1 year. One tooth failed at 3 months, 3 failed at 1 year, with a success rate of 93%. None of the predictors investigated had a significant influence on the outcome of microsurgery. CONCLUSIONS: Premixed fast-set tricalcium silicate putty is a suitable root-end filling material for use in endodontic microsurgery. CLINICAL RELEVANCE: Tricalcium silicate-based cements have shown promising biological properties as a root-end-filling material. Premixed and fast-set formulations achieved high success rates in clinical studies. TRIAL REGISTRATION: Clinicaltrials.gov registration number NCT03733938.

Periodontal response to a tricalcium silicate material or resin composite placed in close contact to the supracrestal tissue attachment: a histomorphometric comparative study.

OBJECTIVE: Subgingival dental restorations and periodontal health have been studied for many years; however, there is a low histological evidence on the behavior of new materials in the supracrestal tissue attachment. The aim of this study is to analyze the periodontal response when a tricalcium silicate material (TSM) or composite margin restorations is placed to 0.5 mm and 1.5 mm from the bone crest with a histomorphometric analysis in dogs. METHODS: Nine mongrel dogs were used in this study: four dogs (8 canine teeth) for TSM group, 4 dogs (8 canine teeth) for composite group, and 1 dog (2 canine teeth) with cavities without restorations. Cavity preparation of 2×2×1 mm was created on the buccal aspect of the canines at 0.5 and 1.5 mm of the crestal bone. Cavities were restored with composite and TSM or were left unrestored as control. After 12 weeks of healing, the dogs were euthanized and blocks containing the tooth and soft tissues were processed. RESULTS: In all the specimens, the junction epithelium was stablished apical to the tooth preparations. A shorter distance to the bone (0.5 cavity) implies greater apical periodontal migration regardless of the material used. In the TSM groups, the connective tissue height and the distance between bone level and apical margin preparation were greater than those in the composite groups, while the epithelium height was less. However, there were no statistically significant differences comparing TSM and composite groups at either 0.5 mm or 1.5 mm (p > 0.05). CONCLUSION: Histologic analysis did not show periodontal reattachment to TSM or composite. In both cases, bone crest migrates apically. For that reason, it is recommended to perform composite restorations at the subgingival level whenever the distance to the bone crest is at least 2 mm. CLINICAL RELEVANCE: Both composite and TSM do not achieve reinsertion of the connective tissue in the biological width.

Cytocompatibility and bioactive properties of the new dual-curing resin-modified calcium silicate-based material for vital pulp therapy.

OBJECTIVE: The aim of the present study was to evaluate the in vitro biocompatibility of Theracal PT, Theracal LC, and MTA Angelus, considered as bioactive materials used for vital pulp treatment, on human dental pulp stem cells (hDPSCs). MATERIALS AND METHODS: Human dental pulp stem cells (hDPSCs) were isolated from third molars, and material eluates were prepared (undiluted, 1:2, and 1:4 ratios). The hDPSC cytotoxicity, adhesion, morphology, viability, and cell migration were assessed. The mineralization nodule formation was determined by Alizarin red S staining (ARS). The odonto/osteogenic differentiation potential was assessed by osteo/odontogenic marker expression real-time qPCR. The chemical composition and ion release of the vital pulp materials were determined by energy dispersive X-ray (EDX) and inductively coupled plasma-mass spectrometry (ICP-MS), respectively. Statistical differences were assessed by ANOVA and Tukey's test (p < 0.05). RESULTS: The three vital pulp materials showed variable levels of calcium, tungsten, silicon, and zirconium release and in their chemical composition. Cytocompatibility assays revealed higher hDPSC viability and migration rates when treated with Theracal PT than with Theracal LC. The lowest cell adhesion and spreading were observed in all Theracal LC-treated groups, whereas the highest were observed when treated with MTA. Theracal PT and MTA promoted the upregulation of DSPP and RUNX2 gene expression (p < 0.05). After 21 days, both MTA Angelus and Theracal PT-treated cells exhibited a significantly higher mineralized nodule formation than the negative control (p < 0.05). CONCLUSIONS: This study demonstrates the favorable in vitro cytocompatibility and bioactive properties of the recently introduced Theracal PT and the well-established MTA Angelus on hDPSCs, as opposed to Theracal LC. More studies, including in vivo animal testing are suggested before these new formulations might be used in the clinical setting. CLINICAL RELEVANCE: Theracal PT is a new material that could be clinically suitable for vital pulp therapy. Further studies considering its biocompatibility and bioactivity are necessary.

Dislodgement resistance and adhesive pattern of different endodontic sealers to dentine wall after artificial ageing: an in-vitro study.

To compare the dislodgement resistance and the adhesive pattern of four different endodontic sealers to root dentine walls. Ninety lower premolars were assigned to five groups (n = 18), Group 1: no sealer (control); Group 2: EndoRez (ERZ); Group 3: Sealapex (SPX); Group 4: EndoSeal MTA (ESA) and Group 5: BioRoot RCS (BRS). They were instrumented up to size 30 taper 0.06 and obturated using single cone technique with matched-taper gutta-percha cones and one of the mentioned sealers. Six teeth from each group were then randomly subjected to 100, 1000 and 10,000 thermocycles, respectively. 1 mm slice of mid root region, measuring 6 mm from the apical foramen was prepared and subjected to push-out test under a Universal Testing Machine. Adhesive patterns of sealers were assessed using a stereomicroscope at 20 × magnification and classified using a new system. Statistical analyses were performed using two-way ANOVA, complemented by Tukey HSD and Chi-square tests. ESA and BRS showed significantly higher (p < 0.05) push-out bond strength, followed by SPX, ERZ and lastly the control, but no significant difference was noted between ESA and BRS (p > 0.05) at 100, 1000 and 10,000 thermocycles, respectively. Both ESA and BRS exhibited a significant higher rate (p < 0.05) of Type 3 and Type 4 adhesive patterns as the thermocycles increased. ESA and BRS demonstrated higher bond strength and better adhesive pattern to root dentine wall than SPX and ERZ, especially after artificial ageing.

Tooth Discoloration Induced by Different Calcium Silicate-Based Cements: A Two-Year Spectrophotometric and Photographic Evaluation in Vitro.

OBJECTIVE: Calcium silicate-based cements (CSCs) may lead to coronal staining in young permanent teeth over the time. The purpose of this study was to evaluate and compare the long-term tooth discoloration induced by different CSCs. STUDY DESIGN: Ninety freshly-extracted human molars were assigned randomly into 6 groups (n=15/group) according to the CSC used as a pulpotomy material: ProRoot MTA, MTA Angelus, NeoMTA, EndoSequence Putty, Biodentine and Negative control (No cement). The color was assessed at baseline, and thereafter at 3, 6, 12 and 24 months by using both a spectrophotometer and digital images taken with and without a cross-polarizing filter. The time-dependent changes in color (ΔE) were compared within and among groups using Analysis of Variance. RESULTS: Angelus MTA and ProRooT MTA showed severe coronal discoloration (p>0.05) starting at 3 months. ΔE values of NeoMTA, EndoSequence Bioceramic Putty and Biodentine were below the perceptibility threshold, with Biodentine showing greater ΔE values than NeoMTA and EndoSequence Putty in the absence of statistical significance (p>0.05). CONCLUSIONS: Discoloration elicited by CSCs may develop soon after placement, and continue to increase for up to two years. Angelus MTA and ProRooT MTA cannot be recommended for vital pulp therapies in the esthetic zone of young individuals.

Comparative Evaluation of Indirect Pulp Therapy in Young Permanent Teeth using Biodentine and Theracal: A Randomized Clinical Trial.

OBJECTIVE: In a tooth with deep dentinal caries; judicious removal of infected dentin and isolating affected dentin from oral fluids with suitable biocompatible material is called indirect pulp therapy (IPT). This randomized clinical trial was done to evaluate and compare the efficacy of Biodentine, Theracal LC and. Dycal as an indirect pulp capping agent in young permanent teeth. STUDY DESIGN: IPT was performed in 60 young permanent molars with caries approaching pulp in 55 healthy children using Biodentine, Theracal and Dycal. A 2-3mm layer of GIC was placed over the intervening material followed by restoration of cavity with composite. Clinical and radiographic examinations were conducted at 3 weeks, 3 months, 6 months,12 months, 18 months and 24 months. The data was compared using chi-square test at a significance level of 0.05. RESULTS: By end of 24 months ,54 teeth presented for follow up with overall success rate of 100% in Theracal, 94.44% in Biodentine, and 77.78% in Dycal. Overall success of Theracal was statistically significant in comparison to Biodentine and Dycal at 24 months follow up (p= 0.03) Conclusions: Radiographic and clinical outcomes of Theracal and Biodentine suggest their use as an alternative material for IPT in young permanent molars with higher success.

Antimicrobial effect of bioceramic cements on multispecies microcosm biofilm: a confocal laser microscopy study.

OBJECTIVES: To assess the viability of multispecies microcosm biofilm after contact with NeoMTA Plus, Biodentine, and MTA Angelus. MATERIALS AND METHODS: Fifty-four human dentin blocks (4 × 5 × 4 mm) were allocated to Hawley retainers, worn by six volunteers for 72 h. The blocks were then individually incubated in BHI broth for 21 days at 37 °C. At the end of experimental time for biofilm growth, the samples were randomly divided into four groups (n = 12): NeoMTA Plus, Biodentine, MTA Angelus, and negative control. The materials were placed in contact with the blocks. All samples were placed in cell-culture plate wells and incubated in BHI broth for 7 days at 37 °C. One sample from each volunteer (n = 6) was analyzed by SEM to describe the biofilm morphology. CLSM was performed to determine the percentage of viable biofilm biovolume. The data were statistically analyzed by one-way ANOVA and Tukey's multiple comparison test (α = 5%). RESULTS: SEM showed biofilm formed by spherical and rod-shaped bacteria surrounded by an extracellular matrix. No material was able to kill all biofilm cells, and all groups had more than 50% of viable bacteria. NeoMTA Plus was significantly different from the negative control group (P < .05). CONCLUSIONS: All tested materials were not effective against multispecies microcosm biofilm. CLINICAL RELEVANCE: NeoMTA Plus, Biodentine, and MTA Angelus were not effective against multispecies microcosm biofilm. It is essential to understand that these bioceramic cements are indicated for infected clinical situations. Thus, complementary disinfection procedures should be conducted prior to filling with these materials.

Effect of previous irrigation with chlorhexidine on the push-out bond strength of a calcium silicate-based material.

This study evaluated the effect of previous irrigation with chlorhexidine (CHX) on the bond strength of a calcium silicate-based material, Biodentine, when used for furcal repair. Furcal perforations were produced in 30 extracted mandibular molars. Teeth were divided into 3 groups according to the irrigant used: distilled water (DW), CHX followed by DW (CHX), and CHX followed by ethylenediaminetetraacetic acid (EDTA) and DW (CHX/EDTA). Biodentine was used to repair the perforations. A push-out bond strength test was performed after 7 days, and data were statistically analyzed using Kruskal-Wallis and Dunn tests (P < 0.05). The CHX/EDTA group showed significantly lower values than the DW and CHX groups (P < 0.05). The failure mode of the DW group was mainly mixed, while that of the CHX group was cohesive. The CHX/EDTA group exhibited adhesive and mixed failures. Irrigation with CHX prior to furcation repair did not result in a statistically significant difference, compared to the use of DW, in the push-out bond strength of Biodentine.

The effect of mixing method on tricalcium silicate-based cement.

AIM: To evaluate the effect of three methods of mixing on the physical and chemical properties of tricalcium silicate-based cements. METHODOLOGY: The materials evaluated were MTA Angelus and Portland cement with 20% zirconium oxide (PC-20-Zr). The cements were mixed using a 3 : 1 powder-to-liquid ratio. The mixing methods were manual (m), trituration (tr) and ultrasonic (us) activation. The materials were characterized by means of scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy. Flowability was analysed according to ANSI/ADA 57/2012. Initial and final setting times were assessed following ASTM C266/08. Volume change was evaluated using a micro-CT volumetric method. Solubility was analysed according to ADA 57/2012. pH and calcium ion release were measured after 3, 24, 72 and 168 h. Statistical analysis was performed using two-way analysis of variance. The level of significance was set at P = 0.05. RESULTS: The SEM analysis revealed that ultrasonic activation was associated with a homogeneous distribution of particles. Flowability, volume change and initial setting time were not influenced by the mixing method (P > 0.05). Solubility was influenced by the mixing method (P < 0.05). For pH, at 168 h, significant differences were found between MTA-m and PC-20-Zr-m (P < 0.05). For calcium ion release, PC-20-Zr-tr had higher values than MTA-m at 3 h, and MTA-tr had higher values than PC-20-Zr-m at 168 h (P < 0.05). CONCLUSIONS: The ultrasonic and trituration methods led to higher calcium ion release and pH compared with manual mixing for all cements, whilst the ultrasonic method produced smaller particles for the PC-20-Zr cement. Flow, setting times and volume change were not influenced by the mixing method used; however, it did have an impact on solubility.

Effect of root canal irrigation protocols on the dislocation resistance of mineral trioxide aggregate-based materials: A systematic review of laboratory studies.

The aim of this systematic review was to address the question: Do different irrigating protocols have an impact on the dislocation resistance of mineral trioxide aggregate (MTA)-based materials? The review was performed using a well-defined search strategy in three databases (PubMed, Scopus, Web of Science) to include laboratory studies performed between January 1995 and May 2017, in accordance with PRISMA guidelines. Two reviewers analysed the papers, assessed the risk of bias and extracted data on teeth used, sample size, size of root canal preparation, type of MTA-based material, irrigants, canal filling method, storage method and duration, region of roots and the parameters of push-out testing (slice thickness, plunger dimensions and plunger loading direction), the main results and dislocation resistance values (in MPa). From 255 studies, 27 were included for full-text analysis. Eight papers that met the inclusion criteria were included in this review. There was a wide variation in dislocation resistance due to differences in irrigation sequence, time and concentration of irrigants, storage method and duration, and the parameters of push-out bond strength testing. A meta-analysis was not done but qualitative synthesis of the included studies was performed. No definitive conclusion could be drawn to evaluate the effect of irrigation protocols on dislocation resistance of MTA-based materials. Recommendations have been provided for standardized testing methods and reporting of future studies, so as to obtain clinically relevant information and to understand the effects of irrigating protocols on root canal sealers and their interactions with the dentine walls of root canals.

A Critical Comparison of 3D Experiments and Simulations of Tricalcium Silicate Hydration.

Advances in nano-computed X-ray tomography (nCT), nano X-ray fluorescence spectrometry (nXRF), and high-performance computing have enabled the first direct comparison between observations of three-dimensional nanoscale microstructure evolution during cement hydration and computer simulations of the same microstructure using HydratiCA. nCT observations of a collection of triclinic tricalcium silicate (Ca3SiO5) particles reacting in a calcium hydroxide solution are reported and compared to simulations that duplicate, as nearly as possible, the thermal and chemical conditions of those experiments. Particular points of comparison are the time dependence of the solid phase volume fractions, spatial distributions, and morphologies. Comparisons made at 7 h of reaction indicate that the simulated and observed volumes of Ca3SiO5 consumed by hydration agree to within the measurement uncertainty. The location of simulated hydration product is qualitatively consistent with the observations, but the outer envelope of hydration product observed by nCT encloses more than twice the volume of hydration product in the simulations at the same time. Simultaneous nXRF measurements of the same observation volume imply calcium and silicon concentrations within the observed hydration product envelope that are consistent with Ca(OH)2 embedded in a sparse network of calcium silicate hydrate (C-S-H) that contains about 70 % occluded porosity in addition to the amount usually accounted as gel porosity. An anomalously large volume of Ca(OH)2 near the particles is observed both in the experiments and in the simulations, and can be explained as originating from the hydration of additional particles outside the field of view. Possible origins of the unusually large amount of observed occluded porosity are discussed.

Bioactive endodontic materials for everyday use: a review.

Bioceramic materials are at the forefront of modern dentistry. Bioactive bioceramic endodontic materials promote pulpal and periapical tissue healing and are easy to use. Dentists can choose among many endodontic materials, depending on their needs. This article highlights the major differences among commercially available bioactive tricalcium silicate bioceramics, commonly known as mineral trioxide aggregate materials, to enable dentists to make appropriate decisions in the selection of these materials.

Biocompatibility and mineralized nodule formation of Neo MTA Plus and an experimental tricalcium silicate cement containing tantalum oxide.

AIM: To evaluate the biocompatibility and mineralized nodule formation of an experimental tricalcium silicate cement with tantalum oxide (TSC/Ta2 O5 ) as radiopacifier, Neo MTA Plus (Avalon Biomed Inc., Bradenton, FL, USA) and MTA (Angelus, Londrina, PR, Brazil) on human osteoblast-like cells (Saos-2). METHODOLOGY: Biocompatibility was evaluated by 3-(4,5-dimethyl-thiazoyl)-2,5-diphenyl-tetrazolium bromide (MTT) and neutral red (NR) assays, after exposure of Saos-2 to cement extracts at 1 : 1, 1 : 2, 1 : 4 and 1 : 8 dilutions for 24 h. Bioactivity was evaluated by alkaline phosphatase (ALP) activity, and calcium deposits were detected with alizarin red staining (ARS). Statistical analysis was performed with analysis of variance and Bonferroni or Tukey post-test (α = 0.05). RESULTS: The MTT assay revealed lower cytotoxicity for NEO and MTA (P < 0.05), and higher for TSC/Ta2 O5 at 1 : 1 and 1 : 2 dilutions when compared to serum-free medium - control (P > 0.05). At 1 : 4 dilution, the TSC/Ta2 O5 cytotoxicity was similar to the control (P > 0.05). At 1 : 8 dilution, cell viability was significantly greater than the control (P < 0.05). Saos-2 cell viability performed using the NR assay at all dilutions revealed no cytotoxic effect of MTA, NEO and TSC/Ta2 O5 . ALP activity at 1 and 3 days was similar to the control (P > 0.05). TSC/Ta2 O5 had significantly greater ALP activity at 7 days when compared with the control (P < 0.05). All materials induced the production of mineralized nodules, and NEO produced significantly more mineralized nodules than MTA and TSC/Ta2 O5 (P < 0.05). CONCLUSIONS: Neo MTA Plus and TSC/Ta2 O5 were biocompatible and induced ALP activity in Saos-2 cells. Both materials induced mineralized nodule formation by Saos-2 with Neo MTA Plus producing significantly more.