White Mineral Trioxide Aggregate Research Articles

Impact of Acidic and Alkaline Environments on the Surface Morphology of Biodentine and White Mineral Trioxide Aggregate - An In-vitro Study.

The physical and chemical properties of calcium silicate cement might be affected due to exposure to acidic or alkaline conditions during clinical use. The present study aimed to evaluate the effect of acidic and alkaline environments on the surface morphology of biodentine (BD) and white mineral trioxide aggregate (wMTA). Disc-shaped specimens of BD (n = 30) and wMTA (n = 30) were prepared in a metal mould and wrapped in pieces of gauze. They were divided into three sub-groups according to the storage media: group A, soaked in sterile distilled water at a pH of 7.0; group B, exposed to butyric acid buffered at pH 4.0; and group C, exposed to calcium hydroxide solution buffered at pH 12.0. The specimens were incubated for 7 days at 37°C, followed by examination under scanning electron microscopy at 1000x and 5000x magnification to characterise the microstructural morphology. Definite changes were seen in the microstructure of BD and wMTA on exposure to acidic and alkaline pH. The microstructure of wMTA tends to exhibit reduced cohesion when exposed to an acidic environment, especially when compared to an alkaline pH. Acidic pH exerts a milder influence on the morphological structure of BD when contrasted with its effects on wMTA. Biodentine may emerge as a more prudent choice than wMTA for utilisation in inflamed periapical regions.

Effects of using different dentin conditioners on dentin regeneration.

This experiment aimed to evaluate the impact of several dentine etching and conditioning agents on growth factors (GFs) liberation from dentine slices. Eighteen dentine slices were obtained from nine premolars divided in to six groups, the slices immersed in one mL test solutions for 5 min; Group 1: white Mineral trioxide aggregate (MTA), Group 2: Phosphate buffered saline (PBS), Group 3: 37% phosphoric acid, Group 4: 17% Ethylenediaminetetraacetic Acid (EDTA), Group 5: 10% Maleic acid (MAc), and Group 6: 0.7% Fumaric acid. The solutions were removed and stored directly at for further detection and quantification of transforming GF beta 1 (TGF-b1), bone morphogenetic protein 2 (BMP2) and vascular endothelial growth factor (VEGF) by enzyme-linked immunosorbent assay (ELISA). One-way ANOVA was used to compare the mean release and standard deviation between groups (α = 0.05). Tukey's post hoc applied for multiple comparisons. After five min conditioning of dentine slices, white MTA released the highest level of TGF-b1, BMP2 and VEGF among all groups, followed by 0.7% Fumaric acid with no significant difference between them, but compared to 37% phosphoric acid and PBS groups significant difference observed, which they released the least amount of GFs amongst all groups. Based on the results of this research the detectable release of TGF-b1, BMP2 and VEGF by 0.7% fumaric acid was comparable with white MTA from dentin slices.

Impact of different disinfection protocols on the bond strength of NeoMTA 2 bioceramic sealer used as a root canal apical plug (in vitro study)

IntroductionTreatment of an immature permanent tooth required a special disinfection protocol due to the presence of thin radicular walls, which are prone to fracture. Mineral Trioxide Aggregate (MTA) has been proposed as a root repair material for root canal treatment. The aim of this in vitro study was to compare the push-out bond strength of conventional White MTA cements and second generation NeoMTA 2 in imitated immature roots treated with different disinfection protocols, which are 5.25% sodium hypochlorite (NaOCl), followed by 17% ethylenediaminetetraacetic acid (EDTA), and NaOCl, followed by 20% etidronic acid (HEBP).MethodsThe root canals of freshly extracted single-root teeth were manually prepared until 90 K-file to imitate immature roots. Roots were randomly divided into four groups (G) according to the disinfection protocol (n = 15 per group). where G1 (NaOCl + EDTA + White MTA) and G2 (NaOCl + EDTA + NeoMTA 2) While G3 (NaOCl + HEBP + White MTA) and G4 (NaOCl + HEBP + NeoMTA 2) All groups were activated with manual agitation. All specimens were incubated for 48 h. The apical third of each root was perpendicularly sectioned to attain a slice of 3 mm thickness. Push-out bond strength values were assessed using a two-way ANOVA and a Student’s t test.ResultsG3 and G4 that were treated with HEPB showed higher significant push-out bond strength mean values than G1 and G2 treated with an EDTA chelating agent. Irrespective of the chelating agent used, it was found that both NeoMTA 2 and White MTA had no significant influence on push-out bond strength mean values (p ≤ 0.05).ConclusionThe combined use of 5.25% NaOCl and 20% HEBP increased the push-out strength values of both NeoMTA 2 and White MTA, rendering them suitable to be used as an alternative chelating agent to EDTA.

Web-Based Survey on Regenerative Endodontic Practices among Members of the American Association of Endodontists

IntroductionThe American Association of Endodontics (AAE) Regenerative Endodontics Committee reports here the web-based survey data of regenerative endodontic procedures performed by the AAE members from 2008 to 2019. MethodsThe web-based survey consisted of 2 questionnaires, a revascularization and a follow-up, including clinical and radiographic data at 3, 6, 12 or >12 months after treatment. Data from demographics, etiology, clinical protocols, radiographic, and clinical outcome as perceived by the clinicians were recorded. From 927 entries, 184 full cases were submitted and 126 were suitable for radiographic analysis. The data were divided into cases with 6–12 months and cases with >12 months recall time. Descriptive statistics and univariate analyses were performed. ResultsPredominantly patients were male (63%), average 10 years-old with anterior teeth (77.2%) due to trauma (69.6%). A wide variation in regenerative endodontic procedures protocols was reported by the AAE members. The most common clinical protocols used minimal instrumentation (75.5%), 2.5% or higher concentrations of sodium hypochlorite (83.7%), and antibiotic paste as intracanal medication (58.7%). The majority reported blood clot formation (56%) and most common coronal capping material was white mineral trioxide aggregates (50.5%). Increases in radiographic root length, and radiographic root area were proportional to the time lapsed after treatment. Overall, case outcomes were categorized by clinicians as successful (54.3%), uncertain (23.9%), and unsuccessful (3.8%). ConclusionsThis web-based survey provides a valuable perspective on case selection, clinical protocols, and perceived outcomes for regenerative endodontic procedures and supports the need for future higher level evidence studies.

Evaluation and Comparative Analysis of Coronal Tooth Discoloration Induced by Four Endodontic Biomaterials Utilized in Regenerative Endodontic Procedures: An Ex-vivo Study.

This study aims to compare and evaluate the changes in color caused by four different biomaterials utilized as intracanal coronal barriers in the regenerative endodontic procedure at varying intervals of time. A total of 100 extracted mandibular single-rooted premolars were taken. Samples were standardized, and access cavity preparation was done. All the canals were instrumented and irrigated thoroughly. They were divided into five groups: A, B, C, D, and E (n=20), i.e., the control group, gray mineral trioxide aggregate (MTA), white MTA, Biodentine, and calcium hydroxide. Each group was further subdivided into two subgroups (n=10), where one subgroup was prepared with normal saline and the other was prepared with platelet-rich fibrin (PRF). Digital photographs were taken at baseline, immediately after the placement of biomaterials, after 72 hours, seven days, and sixmonths, using a DSLR camera. The color evaluation was done using the Adobe Photoshop 2021 software using the CIE L*a*b color system. The data obtained were recorded and statistically analyzed using IBM SPSS Statistics for Windows, Version 23 (Released 2015; IBM Corp., Armonk, New York). Continuous variables were analyzed using a one-way ANOVA test and post-hoc analysis. The P-value was set to be significant at <0.05. Statistically significant variation was obtained in all four experimental groups regarding change in color (ΔE) over periods of 72 hours, seven days, and six months. At six months, all the experimental groups presented with a perceptible color variation (ΔE>3.3). The color change was significant after six months in all groups. Biodentine produced the least color alteration, whereas gray MTA produced the highest.

Pulp regeneration treatment using different bioactive materials in permanent teeth of pediatric subjects

Background and Objectives: The present systematic review aims to assess the success rate of the pulp regeneration treatment, according to the American Association of Endodontists (AAE) criteria, using different bioactive materials in permanent teeth of pediatric subjects (6–17 years of age). Materials and Methods: The study protocol was registered on PROSPERO and adhered to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. The question formulation was accomplished using the PICO model, and an electronic search was carried out on Scopus, MEDLINE/PubMed, Web of Science, and Cochrane databases till April 1, 2023. A total of 30 studies were established to fulfill the inclusion criteria of this systematic review. Results: A total of 273 teeth have been treated with pulp regeneration treatment. By comparing different biomaterials and the success criteria defined by the AAE, the material associated with a higher success rate was found to be the white mineral trioxide aggregate. However, the overall success rate of pulp regeneration treatment was reported for 248 out of 273 teeth (91.20%). Conclusions: Data obtained support the potential that regenerative endodontics aids in continuing root development in permanent immature teeth. Further studies are needed for a more extensive evaluation of the use of different biomaterials and the success rate in regenerative endodontics.

SOLUBILITY AND BIOMINERALIZATION ABILITY OF PMMA BONE CEMENT NANOCOMPOSITE FILLED WITH 40% NANOHYDROXYAPATITE FOR USE AS ROOT-END FILLING MATERIAL

Aim: This study was conducted to compare and evaluate the solubility and biomineralization ability of polymethyl-methacylate bone cement filled with prepared calcium phosphate based nano-fillers versus mineral trioxide aggregate when used as root end filling material. Materials and Methods: A total of forty two samples were prepared and classified into three main groups(n=14)according to the material type: Group I: white mineral trioxide aggregate, Group II: Polymethyl-methacrylate bone cement and Group III: Polymethyl-methacrylate bone cement loaded with 40% of prepared calcium phosphate based nanofillers. Each material type was mixed and packed into molds. Solubility testing was done following the ISO specification #4049 (2009). For the biomineralization ability testing, each specimen was immersed in 150 ml of simulated body fluid for 21 days. After that, the surface of the cements was analyzed by scanning electron microscope and energy dispersive X-ray analysis with computer-controlled software for elemental analysis. Results: Energy dispersive X-ray analysis results revealed the absence of both calcium and phosphorus elements in polymethyl-methacrylate bone cement samples. On the other hand, both calcium and phosphorus elements were present in the other two tested materials samples. Statistical analysis revealed a statistically significant difference between the tested groups (p&lt;0.05). Regarding solubility, MTA (GroupI) was significantly the lowest having mean value of (0.010g/mm3), while Bone cement with nanofiller (group III) was significantly the highest having mean value (1.009 g/mm3). Conclusion: Within the limitations of the present study, it can be concluded that addition of nanohydroxyapatite to polymethyle-methacrylate bone cement enhanced its biomineralization ability to be capable of apatite formation and on the other hand, it increased its solubility.

Discoloration after revascularization using calcium phosphosilicate-based bioceramic versus mineral trioxide aggregate in necrotic immature permanent anterior teeth: A Randomized clinical trial.

The aim of the current study is to evaluate the effect of calcium phophosilicate-based bioceramic "Totalfill bioceramic putty" and white mineral trioxide aggregate (WMTA) as the coronal plug on discoloration after revascularization of necrotic immature permanent anterior teeth. This study was conducted on (48) necrotic young permanent central incisors in children ranging from 8 to 14 years old, that were randomly allocated to either Totalfill bioceramic (Group I = 24) or WMTA (Group II = 24) as the coronal plug. Two visits revascularization protocol was adopted in this study using 1.5% sodium hypochlorite, followed by 17% ethylenediaminetetraacetic acid, and ending with a saline flush as irrigation solution. The double antibiotic paste was used as intracanal medication. The blood clot was used as scaffold followed by the application of collagen membrane followed by coronal plud malterial. Finally, the access was sealed using resin composite restoration and composite restoration. Clinical assessment was conducted at 1, 3, 6, 9, and 12 months, while radiographic assessment was conducted at 6 and 12 months. Data were statistically analyzed using the Chi-squared test for intergroup comparisons and Cochran's Q test for intragroup comparison. Clinically, Group I exhibited a success rate of 100%, whereas Group II exhibited a success rate of 85.7%. Radiographically, both materials showed a 90.5% success rate. There was no statistically significant difference between both materials for all assessed clinical and radiographic parameters at different follow-up periods. Both Totalfill bioceramic putty and WMTA can be used successfully as coronal plug in esthetic areas.

Evaluation of the Marginal Adaptation of Two Hydraulic Calcium Silicate Cements Used in Apical Plugs: An In Vitro Study

Background: The emergence of new hydraulic calcium silicate cements has revolutionized endodontics, addressing the limitations of mineral trioxide aggregate (MTA). The aim of this study is to assess and compare the marginal adaptation of two calcium silicate-based cements (White ProRoot MTA® and TotalFill® BC RRM Fast Set PuttyTM), when creating apical plugs for teeth with open apices. Methods: twenty-four single-rooted teeth were divided into two groups—GMTA (plug with MTA®) and GTBC (plug with TotalFill® BC RRM Fast Set PuttyTM)—and were sectioned at 1 mm and 2 mm from the apex. The transverse sections were analyzed with scanning electron microscopy and the marginal adaptation of the cements was measured with ImageJ® 1.3 software. Statistical analysis (IBM® SPSS® statistics software version 27) was performed and statistical significance was set at 0.05 (p &lt; 0.05). Results: There was a significant difference in the apical region, favoring White ProRoot MTA®, with a lower percentage of marginal adaptation failure (1.32 ± 4.47), presenting a statistically significant difference in the apical region (p = 0.029) but not in the cervical region of the apical plugs (p = 0.774). Conclusions: White ProRoot MTA® showed superior marginal adaptation in the apical section compared to TotalFill® BC RRM Fast Set PuttyTM.

Chemical and physical properties of radiopaque Portland cement formulation with reduced particle size.

This study compared the chemical and physical properties of an experimental radiopaque white Portland cement (REPC) with reduced particle size to ProRoot white mineral trioxide aggregate (WMTA). The particle size distribution of experimental Portland cement (EPC) was examined, and then nano-zirconium oxide (nano-ZrO) was added to produce REPC. Chemical analysis, initial setting time, pH values, and push-out bond strength were evaluated. Results showed that REPC had smallest particle size (354.5±26.45 nm), while PC had the largest (1,309.67±60.54 nm) (p<0.05). Differences in chemical composition were observed. REPC exhibited shorter setting time (32.7±0.58 min) compared to WMTA (131.67±2.89 min) and PC (163.33±2.89 min) (p<0.05). All groups showed alkaline pH (p<0.05). REPC demonstrated the highest push-out bond strength (22.24±4.33 MPa) compared with WMTA (15.53±3.26 MPa) and PC (16.8±5.43 MPa) (p<0.05). This cost-effective PC formulation reduced the setting time and increased the push-out bond strength while maintaining the alkaline properties of the original cements.

Physicochemical properties and antibiofilm activity of mineral trioxide aggregate associated with farnesol.

This study assessed the physicochemical and antibiofilm properties of white mineral trioxide aggregate (MTA) associated with 1 or 2% of farnesol. Setting time was evaluated based on ISO 6876/2012. Radiopacity was evaluated by radiographic analysis. pH was assessed after time intervals of 1, 3, 7, 14, 21, and 28 days. Solubility (% mass loss) and volumetric change (by micro-CT) of the cements were evaluated after immersion in distilled water. The presence of voids inside the materials was assessed by using micro-CT. Antibiofilm activity against Enterococcus faecalis was evaluated by crystal violet assay and the modified direct contact test performed with biofilm previously formed on bovine root dentin for 14 days. Data were submitted to ANOVA/Tukey tests with 5% significance level. The incorporation of farnesol into MTA increased its setting time, but decreased its solubility at 30 days and its volumetric loss in all periods (p < 0.05). Radiopacity and solubility after 7 days were similar among the materials (p > 0.05). The association of farnesol showed the highest pH value after 1 and 3 days (p < 0.05). The association of farnesol with MTA promoted a decrease in the presence of voids, and increased the antimicrobial activity on biofilm biomass of E. faecalis (p < 0.05). In conclusion, the addition of farnesol can be suggested to improve the antimicrobial properties and the consistency of MTA.

Effect of Incorporating Titanium Dioxide Nanoparticles into White Portland Cement, White Mineral Trioxide Aggregate, and Calcium Enriched Mixture Cement on the Push-out Bond Strength to Furcal Area Dentin.

Bond strength of furcation repair materials is an essential factor in clinical success. Studies on the effect of adding titanium dioxide (TiO2) nanoparticles on the push-out bond strength of commonly used endodontic cements for furcation perforation repair is limited. This study aimed to evaluate the effect of adding TiO2 nanoparticles to white Portland cement (PC), white mineral trioxide aggregate (MTA), and calcium enriched mixture cement (CEM) on their push-out bond strengths. In this in vitro study, 120 endodontically treated molars were assigned to six groups (n=20) based on the material used to repair the perforation. In three groups, the cements (white PC, white MTA, and CEM) were placed in pure form, and in the three remaining groups, 1 weight % of TiO2 was added. The push-out bond strength was measured using a universal testing machine at a strain rate of 0.5 mm/min. Data were analyzed using one-way ANOVA and post hoc Games-Howell test (p< 0.05). One-way ANOVA showed significant differences in the mean bond strength values between the six groups (p= 0.002). The post hoc Games-Howell test showed that the bond strengths in MTA+TiO2 and PC+TiO2 groups were significantly higher than those in MTA and PC groups, respectively. However, there was no significant difference in the bond strength between CEM and CEM+ TiO2 groups. The incorporation of TiO2 into MTA and PC increased their push-out bond strength. However, it did not affect the push-out bond strength of CEM cement.

Comparative Evaluation of the Physical and Antimicrobial Properties of Mineral Trioxide Aggregate, Biodentine, and a Modified Fast-Setting Mineral Trioxide Aggregate Without Tricalcium Aluminate: An In Vitro Study.

Background Tricalcium aluminate, one of the major constituents of mineral trioxide aggregate (MTA), has been shown to have cytotoxic properties. Mineral trioxide aggregate has moderate to low antimicrobial activity against the most common endodontic pathogen, Enterococcus faecalis. Aim To assess the physical and antimicrobial properties of a newly modified formulation of mineral trioxide aggregate. Materials & methods The final setting time, compressive strength, and antimicrobial properties were tested for three groups of materials. The material used for Group 1 was mineral trioxide aggregate (white MTA, Angelus, Londrina, Brazil); the material for Group 2 was Biodentine (Septodont, Saint Maur des Fossés, France); and for Group 3, a modified MTA formulation was used. Results Group 1 had the longest setting time, and Group 2 had the shortest setting time. Group 3's material was set at 83.65 ± 0.28 minutes. This difference among the groups was statistically significant (p < 0.05). The highest mean compressive strength during all the time periods was seen in Group 2, followed by Group 3, and the least in Group 1. This difference in compressive strength was statistically significant (p=0.001). The largest zone of inhibition against Enterococcus faecalis, Candida albicans, and Streptococcus mutans was seen in Group 3, followed by Group 2 and Group 1. Conclusion Under the limitations of the present study, the newly modified MTA could serve as an alternative to the conventional MTA in terms of faster setting, higher strength, and better antimicrobial properties.

Spectrophotometric Analysis of Coronal Discoloration In Vitro Induced by Bioceramic Cements.

The aim of this study was to evaluate and quantify, in vitro, the extent of coronal discoloration induced by bioceramic materials over time. In total, 44 human monoradicular teeth were divided into four groups (n = 11), according to the applied material: Negative control (NC); White MTA ProRoot® (WMTAP); Biodentine™ (BD); and TotalFill® BC RRM™ Putty (TF). Teeth were immersed in saline solution and incubated at 37 °C; the following periods of time were defined: before incubation: [t0]-without bioceramic material, t1-immediately after the bioceramic material placement; after incubation: t24h-24 h, t7d-7 days, and 30d-30 days. Descriptive and inferential statistical analysis were performed. Cochran's Q test was used to evaluate coronal discoloration across the different groups, while the Kruskal-Wallis test was employed to determine differences in discoloration among the groups at each time interval. Additionally, the Friedman test was applied to analyze the variations in discoloration within each group over time. A significance level of 5% was set. All experimental groups revealed coronal discoloration over time: NC (p = 0.001), WMTAP (p < 0.001), BD (p = 0.001), and TF (p = 0.006). No significant differences were observed between groups for each time interval (p > 0.05). The WMTAP group varied the most considering the intervals [t0-t1] and [t24h-t7d] (p = 0.037) compared to the remaining experimental groups.

Effect of Different Irrigation Activation and Condensation Techniques on the Marginal Adaptation of White MTA

Effect of Different Irrigation Activation and Condensation Techniques on the Marginal Adaptation of White MTA

Clinical and radiographic evaluation of NeoMTA versus conventional white mineral trioxide aggregate in revascularization of non-vital immature permanent anterior teeth (A randomized controlled trial)

ObjectiveTo evaluate and compare clinically and radiographically the effect of using two different coronal plug materials (NeoMTA versus Conventional White mineral trioxide aggregate) in revascularization of non-vital immature permanent anterior teeth, with special reference to the assessment and evaluation of discoloration potential over a period of one year.MethodsRevascularization procedure was performed in (30) immature permanent non-vital anterior teeth which were randomly allocated to two equal groups (n = 15). NeoMTA was used as coronal plug material in the Experimental Group (N), while conventional White mineral trioxide aggregate (WMTA) was used as a coronal plug material in the Control Group (W). All treated teeth were evaluated clinically at 1 week, 1, 3, and 12 months and radiographically at 12 months.ResultsThe overall clinical and radiographic success rate of Groups (N) and (W) at the end of the 12-month follow-up period was 100%. The discoloration was detected in a single tooth (9.1%) in Group (N) and three teeth (27.3%) in Group (W) but the difference between groups was not statistically significant.ConclusionsBoth NeoMTA and conventional WMTA were successful coronal plug materials in the revascularization of non-vital immature permanent teeth achieving a high level of clinical and radiographic success. NeoMTA is a promising coronal plug material that can be used for revascularization procedures in the esthetic zone as it showed less discoloration potential compared with conventional WMTA, however, there was no statistically significant difference between both materials.

Effect of Intracoronal Sealing Biomaterials on the Histological Outcome of Endodontic Revitalisation in Immature Sheep Teeth—A Pilot Study

The influence of intracoronal sealing biomaterials on the newly formed regenerative tissue after endodontic revitalisation therapy remains unexplored. The objective of this study was to compare the gene expression profiles of two different tricalcium silicate-based biomaterials alongside the histological outcomes of endodontic revitalisation therapy in immature sheep teeth. The messenger RNA expression of TGF-β, BMP2, BGLAP, VEGFA, WNT5A, MMP1, TNF-α and SMAD6 was evaluated after 1 day with qRT-PCR. For evaluation of histological outcomes, revitalisation therapy was performed using Biodentine (n = 4) or ProRoot white mineral trioxide aggregate (WMTA) (n = 4) in immature sheep according to the European Society of Endodontology position statement. After 6 months' follow-up, one tooth in the Biodentine group was lost to avulsion. Histologically, extent of inflammation, presence or absence of tissue with cellularity and vascularity inside the pulp space, area of tissue with cellularity and vascularity, length of odontoblast lining attached to the dentinal wall, number and area of blood vessels and area of empty root canal space were measured by two independent investigators. All continuous data were subjected to statistical analysis using Wilcoxon matched-pairs signed rank test at a significance level of p < 0.05. Biodentine and ProRoot WMTA upregulated the genes responsible for odontoblast differentiation, mineralisation and angiogenesis. Biodentine induced the formation of a significantly larger area of neoformed tissue with cellularity, vascularity and increased length of odontoblast lining attached to the dentinal walls compared to ProRoot WMTA (p < 0.05), but future studies with larger sample size and adequate power as estimated by the results of this pilot study would confirm the effect of intracoronal sealing biomaterials on the histological outcome of endodontic revitalisation.

In Vivo Assessment of the Apatite-Forming Ability of New-Generation Hydraulic Calcium Silicate Cements Using a Rat Subcutaneous Implantation Model.

Hydroxyapatite formation on endodontic hydraulic calcium silicate cements (HCSCs) plays a significant role in sealing the root canal system and elevating the hard-tissue inductivity of the materials. This study evaluated the in vivo apatite-forming ability of 13 new-generation HCSCs using an original HCSC (white ProRoot MTA: PR) as a positive control. The HCSCs were loaded into polytetrafluoroethylene tubes and implanted in the subcutaneous tissue of 4-week-old male Wistar rats. At 28 days after implantation, hydroxyapatite formation on the HCSC implants was assessed with micro-Raman spectroscopy, surface ultrastructural and elemental characterization, and elemental mapping of the material-tissue interface. Seven new-generation HCSCs and PR had a Raman band for hydroxyapatite (v1 PO43- band at 960 cm-1) and hydroxyapatite-like calcium-phosphorus-rich spherical precipitates on the surfaces. The other six HCSCs with neither the hydroxyapatite Raman band nor hydroxyapatite-like spherical precipitates did not show calcium-phosphorus-rich hydroxyapatite-layer-like regions in the elemental mapping. These results indicated that 6 of the 13 new-generation HCSCs possessed little or no ability to produce hydroxyapatite in vivo, unlike PR. The weak in vivo apatite-forming ability of the six HCSCs may have a negative impact on their clinical performance.

Effect of different root canal irrigants on push-out bond strength of two novel root-end filling materials

BackgroundThe aim of this in vitro study was to evaluate push-out bond strength of different root-end filling materials using various irrigant solutions.MethodsA push-out bond strength test was performed to evaluate the bond strength of two experimental root-end filling materials: namely, nano-hybrid mineral trioxide aggregate (MTA) and polymethyl methacrylate (PMMA) cement filled with 20% weight nano hydroxyapatite (nHA) fillers compared to conventional MTA. The irrigant solutions employed were sodium hypochlorite (NaOCl) in concentrations 1%, 2.5% and 5.25% and 2% chlorhexidine gluconate (CHX) followed by application of 17% ethylene diamine tetra-acetic acid (EDTA). A freshly extracted sixty single-rooted human maxillary central incisors were used. The crowns were removed, the canal apex was widened to simulate immature teeth. Each type of irrigation protocols was performed. After application and setting of the root-end filling materials, a slice of one mm thickness was cut transversely from the apical end of each root. Specimens were stored for 1 month in artificial saliva and were subjected to a push-out test to evaluate the shear bond strength. Data were analyzed using two-way ANOVA and Tukey test.ResultsThe experimental nano-hybrid MTA showed the highest significant push-out bond strength values when irrigated by NaOCl at several concentrations (1%, 2.5% and 5.25%) (P< 0.05). Meanwhile, irrigation with 2% CHX resulted in highest bond strength values in nano-hybrid white MTA (18 MPa) and PMMA filled with 20% weight nHA (17.4 MPa) with nonsignificant difference between them (p = 0.25). In each root-end filling material, irrigation with 2% CHX led to the highest significant bond strength, followed by NaOCl 1%, while the least significant bond strength was produced after irrigation with NaOCl 2.5% and 5.25% (P< 0.05).ConclusionConsidering the limitations of this study, it may be concluded that the application of 2% CXH and 17% EDTA provides superior push-out bond strength to root canal dentin compared with irrigation with NaOCl irrigants and 17% EDTA, experimental nano-hybrid MTA root-end filling material provides enhanced shear bond strength than conventional micron-sized MTA root-end filling material.

Synthesis of White Mineral Trioxide Aggregate (WMTA) Using Silica from Rice Husk and Calcium Carbonate from Limestone

White Mineral Trioxide Aggregate (WMTA) was produced using silica as the initial material extracted from rice husk ash and calcium carbonate limestone. This research was initiated by calcinating rice husk ash at 700°C for 3 hours. Silica extraction was performed using 2 M NaOH and added HCl. The extract precipitate was washed using deionized water. Calcium carbonate was made from limestone using 1 M HNO3 and NH3 and continued with carbonation. WMTA was produced by mixing SiO2, CaCO3, and Al2O3. The mixture was homogenized with deionized water and heated, then pellets calcined made at a temperature of 1000°C, and calcination products were added Bi2O3. Synthesized WMTA characterized using TGA/DSC, FTIR, and XRD showed the presence of Ca3SiO5, Ca2SiO4, and Ca3Al2O6 phases, which were like ProRoot’s WMTA.