White-colored Mineral Trioxide Aggregate Research Articles

Experimental Pulp-Capping Agent Radiopaque Dicalcium Silicate Cement Facilitates Dentinogenesis

This study was designed to comparatively evaluate an experimental pulp-capping agent radiopaque dicalcium silicate cement (RDSC), white-colored mineral trioxide aggregate (WMTA), iRoot BP Plus and Biodentine both ex vivo and in vivo. Fourier Transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) were utilized to analyze the phase composition of pulp-capping agents. The surface morphology and element analysis were finished by Scanning electron microscopy (SEM) and Energy Dispersive X-Ray Spectroscopy (EDX). Color stability of the cements and pulp responses induced by different cements were examined by ex-vivo human tooth culture model and in-vivo miniature pig model. Micro-computed tomography was used for quantitative evaluation of the newly formed mineralized tissue. RDSC exhibited discoloration in both models, while WMTA exhibited more visible discoloration. The occurrence of discoloration for WMTA was significantly higher than that of RDSC (p < 0.05), iRoot BP Plus and Biodentine on the 7th day, also higher (p < 0.05) than that of iRoot BP Plus and Biodentine on the 70th day. Mineralized foci were noted in all 7-days groups except the control group both ex vivo and in vivo. Intact and complete reparative dentin bridge formation which possessed tubular structures was noted in all 70-days groups in vivo. RDSC appeared to induce the thickest dentin bridge formation among all these pulp-capping agents which showed statistically significant difference to that of Biodentine (p < 0.05). With decent biological properties, RDSC may have the potential to be a pulp-capping agent recommended in the non-aesthetic area alternative to WMTA, Biodentine and iRoot BP Plus.

Physicochemical properties and osteogenic activity of radiopaque calcium silicate-gelatin cements.

The purpose of this study is to evaluate the physicochemical properties and in vitro osteogenic activity of radiopaque calcium silicate-gelatin cements. The radiopacity, setting time, working time, flow, diametral tensile strength, pH value, washout resistance and morphology of the cements with gelatin (0, 5 and 10% by weight) were measured, which compared to a popular endodontic material, ProRoot white-colored mineral trioxide aggregate (WMTA). The cell morphology, cell attachment and proliferation, alkaline phosphatase and osteocalcin levels on the cements were measured by culturing the specimens with dental pulp cells. The results indicated that the presence of gelatin significantly (P < 0.05) reduced radiopacity and diametral tensile strength and prolonged setting time. Nevertheless, the 5 wt% gelatin cement had a radiopacity (5.1 mm of Al thickness) higher than ISO 6876:2001 standards (3 mm of Al thickness). The setting time (33 min), working time (9 min) and flow value (17.4 mm) of the 5 wt% gelatin cement were significantly (P < 0.05) better than those of WMTA (corresponding 165, 6 min and 14.2 mm). The fresh WMTA completely degraded after soaking in a physiological solution for 1 h, while the gelatin cements resisted washout, showing no noticeable breakdown even after 1 day of soaking. The gelatin cement enhanced the higher expression of cell attachment, proliferation and differentiation as compared to WMTA. It was concluded that the 5 wt% gelatin-calcium silicate hybrid cement appears to be promising as a radiopaque biomaterial for medical applications such as endodontics and vertebroplasty.

Evaluation of antifungal activity of white-colored mineral trioxide aggregate on different strains of Candida albicans in vitro.

Aim:The purpose of this study was to evaluate the antifungal action of various concentrations of white mineral trioxide aggregate (MTA) against seven different strains of Candida albicans using the tube dilution test.Materials and Methods:Fresh mix of MTA was prepared at concentrations of 100, 50, 25, and 12.5 mg/ml and added to a broth tube containing Sabouraud's liquid medium. A total of 1287 broth tubes were prepared and divided into experimental and control groups. Stock cultures of seven strains of C. albicans were obtained. Fresh inoculate of the microorganism was prepared by growing overnight cultures. Aliquots of the test C. albicans were taken and added to the test tubes. All tubes were incubated at 37°C for 1-, 24-, 72-, and 168-h time periods. At each time period, the presence of C. albicans colonies was assessed.Statistical analysis used:Differences among the groups were statistically analyzed using Kruskal–Wallis and Mann–Whitney U tests.Results:Results showed that one strain showed resistance even after 3 days at the lower MTA concentrations of 12.5 and 25 mg/ml. Growth reoccurred with three strains at MTA concentration of 12.5 mg/ml after 7 days. A significant difference was found between strain 3 and other strains at MTA concentrations of 12.5 and 25 mg/ml at the 3-days time period and between tubes containing 12.5 mg/ml and tubes containing higher concentrations of MTA at the 7-days time period.Conclusion:White MTA in concentrations of 100 and 50 mg/ml is effective in inhibiting the seven tested strains of C. albicans for periods up to 1 week.

Comparative Osteogenesis of Radiopaque Dicalcium Silicate Cement and White-Colored Mineral Trioxide Aggregate in a Rabbit Femur Model.

The radiopaque dicalcium silicate cement (RDSC) displayed a shortened setting time and good biocompatibility. This study aimed to compare the regenerative potential of RDSC and white-colored mineral trioxide aggregate (WMTA) using a rabbit femur model. The animals were sacrificed at one, three and six months to accomplish histological and biochemical analyses. The results indicated that after one month of implantation, WMTA was associated with a greyish color alteration within its mass, while RDSC presented color stability even at six months. Histological assay with Masson’s Trichrome and Von Kossa stains showed the presence of newly formed bone surrounding the implanted sites in the rabbit femur. The histochemical data revealed that the RDSC group had significantly more bone regeneration than did the WMTA groups at three and six months. The conclusion drawn is that the encouraging results support the potential applications of RDSC as an improved alternative to WMTA for endodontic uses.

Effect of acid etching on marginal adaptation of mineral trioxide aggregate to apical dentin: microcomputed tomography and scanning electron microscopy analysis

The present investigation assessed the effect of acid etching on marginal adaptation of white- and gray-colored mineral trioxide aggregate (MTA) to apical dentin using microcomputed tomography (micro-CT) and scanning electron microscopy (SEM). Sixty-four extracted single-rooted human maxillary teeth were used. Following root-end resection and apical preparation, the teeth were equally divided into four groups according to the following root end filling materials: (i) white-colored MTA (WMTA), (ii) etched WMTA (EWMTA), (iii) gray-colored MTA (GMTA) and (iv) etched GMTA (EGMTA). After 48 h, the interface between root-end filling materials and the dentinal walls was assessed using micro-CT and SEM. Data were statistically analyzed using the Kruskal–Wallis and Dunn tests. Micro-CT analysis revealed gap volumes between the apical cavity dentin walls and EGMTA, GMTA, EWMTA and WMTA of (0.007 1±0.004) mm3, (0.053±0.002) mm3, (0.003 6±0.001) mm3 and (0.005 9±0.002) mm3 respectively. SEM analysis revealed gap sizes for EGMTA, WMTA, EWMTA and GMTA to be (492.3±13.8) µm, (594.5±17.12) µm, (543.1±15.33) µm and (910.7±26.2) µm respectively. A significant difference in gap size between root end preparations filled with GMTA and EGMTA was found (P<0.05). No significance difference in gap size between WMTA and EWMTA were found in either SEM or micro-CT analysis. In conclusion, pre-etching of apical dentin can provide a better seal for GMTA but not for WMTA.

Comparative Physicochemical and Biocompatible Properties of Radiopaque Dicalcium Silicate Cement and Mineral Trioxide Aggregate

Introduction The purpose of this study was to comparatively examine physicochemical and biocompatible properties of 20 wt% bismuth oxide (Bi 2O 3)-containing dicalcium silicate cement and white-colored mineral trioxide aggregate (WMTA). Methods The radiopacity, setting time, diametral tensile strength, pH value, morphology, and phase composition of the cements with and without Bi 2O 3 were measured after mixing powders with water. Cement biocompatibility was evaluated by incubating the cement specimens with MG63 human osteoblast-like cells. Results The addition of Bi 2O 3 to the cement led to a significant increase ( p < .05) in the setting time of 24 minutes. It was accompanied by a small decrease in the pH value but without adversely affecting diametral tensile strength. The radiopacity value of the Bi 2O 3-containing cement was equivalent to 7.3 mm of aluminum, which was significantly higher ( p < 0.05) than pure cement without Bi 2O 3 (1.1 mm of aluminum) but lower ( p < .05) than WMTA (9.3 mm of aluminum). However, it was greater than 3 mm of aluminum, which is the value recommended by ISO 6876/2001 standards. MG63 cell viability cultured on Bi 2O 3-containing cement was higher than that cultured on WMTA at all culture times. Conclusions The dicalcium silicate cement with 20 wt% Bi 2O 3 showed shortened setting time and good biocompatibility and thus may have the potential to be a root-end filling material alternative to MTA.

The Effect of a Physiologic Solution pH on Properties of White Mineral Trioxide Aggregate

The purpose of this study was to investigate the effect of two solutions differing by pH (6.4 and 4.0) and the use of a setting accelerator (15% Na 2HPO 4 solution) on the properties of white-colored mineral trioxide aggregate (WMTA). These studies indicated that pH 4.0 had a deleterious effect on the morphology of WMTA mixed with water, however, not for WMTA mixed with Na 2HPO 4. When immersed in a pH 4.0 solution for 7 days, WMTA mixed with water or Na 2HPO 4 achieved a diametral tensile strength of 7.9 and 9.0 MPa, respectively, which was significantly lower (p < 0.05) than those obtained at pH 6.4 (11.2 and 12.0 MPa) but significantly higher (p < 0.05) than day 0 samples (4.4 and 4.8 MPa). Mixing WMTA with the accelerator did not significantly affect the microstructure, solubility, or strength in an acidic environment.

The Effect of Setting Accelerator on Properties of Mineral Trioxide Aggregate

The purpose of this study was to investigate the effect of a sodium phosphate dibasic (Na2HPO4) setting accelerator on the properties of white-colored mineral trioxide aggregate (WMTA). Setting times were measured by using a Gilmore needle. Changes in the pH value, diametral tensile strength, and phase composition of WMTA were evaluated. By using a 15% Na2HPO4 solution as a liquid phase mixed with WMTA, the setting time was significantly reduced to 26 minutes rather than the usual 3 hours. The 15% Na2HPO4 promoted WMTA to achieve a maximum diametral tensile strength of 4.9 MPa at an initial 6-hour aging time and 1 MPa for the cement mixed with water. The pH value of the 15% Na2HPO4-mixed cement was changed from an initial 11.0 to a high of 13.2, which was similar to the results using water. The results suggest that the Na2HPO4 solution may be an effective setting accelerator for WMTA.

In vitro evaluation of antifungal effects of mineral trioxide aggregate and portland cement on Candida albicans.

Candida Albicans (CA) is by far the most common yeast of oral infections, including endodontic infections. The aim of this study was to evaluate and compare the antifungal effect of white-colored mineral trioxide aggregate (WMTA) and Portland Cement (PC) using a tube-dilution test. WMTA and PC were tested freshly mixed and after 24 h. The experiment was performed in 24-well culture plates. Fifty wells were used and divided into four experimental groups (freshly-mixed WMTA freshly-mixed PC, 24 h-set WMTA, and 24 h-set PC) of 10 wells each and control groups of five wells each. Plates of Sabouraud dextrose agar mixed with CA served as positive control and Sabouraud dextrose agar without CA served as negative control. Fresh inoculate of CA was prepared by growing an overnight culture from a stock culture. Aliquots of CA were then taken from the stock culture and plated on the agar compound of the experimental and control groups. All plates were incubated at 37°C for1h, 24 h, and 72 h. Growth of fungi was monitored daily by the presence of turbidity. Kruskal-Wallis test was used for data analysis. Findings showed that in the freshly mixed as well as 24 h-set WMTA and PC, fungal growth was observed during 1 h incubation; whereas by increasing the incubation time, no fungal growth was observed in 24 h and 72 h. It was concluded that WMTA and PC (freshly mixed and 24-h set) were effective against CA.

Antibacterial Effect of Two Mineral Trioxide Aggregate (MTA) Preparations Against Enterococcus faecalis and Streptococcus sanguis In Vitro

The antibacterial effects of gray-colored MTA (GMTA) and white-colored MTA (WMTA) against Enterococcus faecalis and Streptococcus sanguis were assessed in vitro using the tube dilution test. Broth tubes were prepared and divided into experimental and control groups. Aliquots of each of the tested microorganisms were taken from a stock culture and added to each experimental and positive control group. All groups were incubated at 37°C and evaluated for turbidity at 0, 1, 24, 48, and 72-hour time periods. A direct correlation was found between GMTA and WMTA concentrations and their antibacterial effect. Tubes containing GMTA in concentrations of 50, 25, and 12.5 mg/ml did not show E. faecalis growth at any of the time periods tested whereas tubes containing WMTA showed E. faecalis growth at all concentrations and time periods tested. Statistically significant differences were found between tubes containing GMTA in concentrations of 50, 25 and 12.5 mg/ml and tubes containing similar concentrations of WMTA (p < 0.001). Tubes containing GMTA in concentrations of 50, 25, 12.5, 6.25, and 3.12 mg/ml and tubes containing WMTA in concentrations of 50, 25, and 12.5 mg/ml did not show S. sanguis growth at any of the time periods tested. Statistically significant differences were found between tubes containing GMTA in concentrations 6.25 and 3.12 mg/ml and tubes containing similar concentrations of WMTA (p < 0.001). It appears that the susceptibility of E. faecalis and S. sanguis to MTA differed and that GMTA requires lower concentrations than WMTA to exert the same antibacterial effect against each of the microorganisms tested.

Comparison of Antifungal Activity of White-Colored and Gray-Colored Mineral Trioxide Aggregate (MTA) at Similar Concentrations Against Candida albicans

The killing effect of similar concentrations of white-colored MTA and gray-colored MTA against Candida albicans was assessed in vitro using the tube dilution test. A direct correlation was found between MTA concentration and its killing effect on C. albicans. At time period zero, both white-colored and gray-colored MTA samples showed Candida growth regardless of the concentration. Tubes containing gray-colored MTA in concentrations of 50, 25, 12.5, 6.25, and 3.125 mg/ml and tubes containing white-colored MTA in concentrations of 50 and 25 mg/ml did not show C. albicans growth at any of the other time periods tested. Tubes containing white-colored MTA in concentrations of 12.5 mg/ml or less showed Candida growth at all the time periods tested. Statistically, a significant difference was found between tubes containing either 50 mg/ml or 25 mg/ml and tubes containing lower concentrations of white-colored MTA (p < 0.001). A significant difference was also found between tubes containing gray-colored MTA in concentrations of 12.5 mg/ml or less and tubes containing similar concentrations of white-colored MTA (p < 0.001). It appears that both gray-colored and white-colored MTA in concentrations of 50 mg/ml and 25 mg/ml are effective in killing C. albicans for periods of up to 1 wk. Lower concentrations of gray-colored MTA may still be effective while lower concentrations of white-colored MTA may not.

Effect of White-Colored Mineral Trioxide Aggregate in Different Concentrations on Candida albicans In Vitro

The antifungal action of different concentrations of white-colored mineral trioxide aggregate (MTA) against Candida albicans was assessed in vitro. Fresh mix of MTA was prepared at concentrations varying from 0.78 mg/ml to 50 mg/ml by dilution with 10 ml molten agar at 45°C. The MTA-agar compound was thoroughly mixed and the uniform mix was then poured into sterile Petri dishes and allowed to set. A total of 348 agar plates were prepared and divided into experimental groups of 11 plates each and control groups of 5 plates each. Plates of agar without MTA served as positive control and plates without C. albicans served as negative control. Fresh inoculate of C. albicans was prepared by growing an overnight culture from a stock culture. Aliquots of C. albicans were then taken from the stock culture and plated on the agar compound of the experimental and positive control groups. All plates were incubated at 37°C for 1, 24, 48, and 72-h periods. At each time period, the presence of C. albicans colonies was assessed and recorded. A direct correlation was found between MTA concentration and its inhibition effect on C. albicans growth. Plates containing MTA in concentration of 50 mg/ml showed significantly better killing action against C. albicans in all of the time periods tested (p < 0.001). Plates containing MTA in concentration of 25 mg/ml showed antifungal activity only at 1 and 24-h time periods. Plates containing lower concentrations of MTA did not show any antifungal activity. It appears that under the conditions of this study, white-colored MTA in concentration of 50 mg/ml is effective in killing C. albicans for periods of up to 3 days. Lower MTA concentrations may not be effective.

Human Saliva Penetration of Root Canals Obturated with Two Types of Mineral Trioxide Aggregate Cements

The sealing ability of orthograde mineral trioxide aggregate (MTA) root canal filling against human saliva was assessed in vitro. Leakage of gray-colored MTA, white-colored MTA and vertically condensed gutta-percha and sealer were compared. Forty-three extracted single-rooted human teeth were serially instrumented to a file size 40/0.06 at the apex and obturated with either gray-colored MTA (group A), white-colored MTA (group B), or gutta-percha and Kerr Canal Sealer EWT (group C). The teeth were then mounted in a model to test for saliva leakage. After 42 days, one root in group A (9.1%), four roots in group B (36.4%), and nine roots in group C (81.8%) showed saliva leakage. Statistically, a significant difference was found between group A and group C (p < 0.001). No statistical difference was found between group A and group B. Out of the root samples that leaked, the one sample in group A leaked after 36 days. Of the four samples in group B, one sample leaked after 32 days, one sample after 33 days, and two samples after 39 days. All nine samples in group C had leaked after 19 days. It appears that under the conditions of this study both MTA preparations may be more resistant to human saliva leakage than vertically condensed gutta-percha and sealer.