Evaluation of pH, calcium ion release and antimicrobial activity of a new calcium aluminate cement.

This study evaluated the pH, calcium ion release and antimicrobial activity of EndoBinder (EB), containing different radiopacifiers: bismuth oxide (Bi2O3), zinc oxide (ZnO) or zirconium oxide (ZrO2), in comparison to MTA. For pH and calcium ion release tests, 5 specimens per group (n=5) were immersed into 10 mL of distilled and deionized water at 37°C. After 2, 4, 12, 24, 48 h; 7, 14 and 28 days, the pH was measured and calcium ion release quantified in an atomic absorption spectrophotometer. For antimicrobial activity, the cements were tested against S. aureus, E. coli, E. faecalis and C. albicans, in triplicate. MTA presented higher values for pH and calcium ion release than the other groups, however, with no statistically significant difference after 28 days (p>0.05); and the largest inhibition halos for all strains, with no significant difference (E. coli and E. faecalis) for pure EB and EB+Bi2O3 (p>0.05). EB presented similar performance to that of MTA as regards pH and calcium ion release; however, when ZnO and ZrO2 were used, EB did not present antimicrobial activity against some strains.

Evaluation of pH, calcium ion release and antimicrobial activity of a new calcium aluminate cement

This study evaluated the pH, calcium ion release and antimicrobial activity of EndoBinder (EB), containing different radiopacifiers: bismuth oxide (Bi2O3), zinc oxide (ZnO) or zirconium oxide (ZrO2), in comparison to MTA. For pH and calcium ion release tests, 5 specimens per group (n = 5) were immersed into 10 mL of distilled and deionized water at 37°C. After 2, 4, 12, 24, 48 h; 7, 14 and 28 days, the pH was measured and calcium ion release quantified in an atomic absorption spectrophotometer. For antimicrobial activity, the cements were tested against S. aureus, E. coli, E. faecalis and C. albicans, in triplicate. MTA presented higher values for pH and calcium ion release than the other groups, however, with no statistically significant difference after 28 days (p > 0.05); and the largest inhibition halos for all strains, with no significant difference (E. coli and E. faecalis) for pure EB and EB + Bi2O3 (p > 0.05). EB presented similar performance to that of MTA as regards pH and calcium ion release; however, when ZnO and ZrO2 were used, EB did not present antimicrobial activity against some strains.

Staining susceptibility of new calcium aluminate cement (EndoBinder) in teeth: a 1-year in vitro study.

AIM: To evaluate the staining susceptibility of new calcium aluminate cement (EndoBinder, EB) in teeth, with or without radiopacifying agent, in comparison with mineral trioxide aggregate (MTA). MATERIALS AND METHODS: Forty bovine incisors were used. After biomechanical preparation and filling, 2 mm of their fillings were removed for cervical plug fabrication (n = 10): EB without radiopacifier; EndoBinder + Bismuth Oxide (EBBO); Gray mineral trioxide aggregate (GMTA) and White mineral trioxide aggregate (WMTA). After teeth restoration, initial color readout was taken (Easyshade - CIE Lab) on the vestibular face. The teeth were stored in artificial saliva at 37°C for 1 year, and after time intervals of 30, 180, and 360 days, new color readouts were taken to determine color alteration (ΔE) in comparison with the initial readout (baseline). RESULTS: The results (2-way anova repeated measures, Bonferroni - P < 0.05) demonstrated that after 360 days, all groups presented ΔE above the clinically accepted limit (ΔE ≥ 3.3), however, without significant difference among them (P > 0.05). All groups presented decrease in ΔL values over the course of time, and the greatest variation occurred for WMTA, with significant difference in comparison with EB and EBBO (P < 0.05). CONCLUSIONS: Some negative features of MTA, such as the high incidence of dental structures staining justify the development of new materials. GMTA, WMTA, and EB with and without radiopacifying agent displayed color alteration (ΔE) after 360 days; however, the luminosity change (ΔL) was lower in EB in comparison with GMTA and WMTA.

Biocompatibility of new calcium aluminate cement (EndoBinder).

INTRODUCTION: The purpose of this study was to evaluate the biocompatibility of calcium aluminate cement (EndoBinder) in subcutaneous tissue of rats. METHODS: Fifteen rats, weighing 300 g, were separated into 3 groups (n = 5) in accordance with the time of death (7, 21, 42 days). Two incisions were made in the dorsal subcutaneous tissue of each rat in which were implanted 2 polyethylene tubes filled with the test materials, EndoBinder (EB) and Grey MTA (GMTA). The external tube walls were considered the negative control group (CG). After 7, 21, and 42 days, animals were killed, obtaining 5 samples per group, at each time interval of analysis. RESULTS: From the morphologic and morphometric analyses by using a score of (0-3) (50, 100, and 400×), results showed absence of inflammatory reaction (0) for EB after 42 days. However, for GMTA, a slight inflammatory reaction (1) was observed after 42 days, which means the persistence of a chronic inflammatory process. When compared with CG, tissue reaction ranging from discrete (1-7 days) to absent (0-42 days) was observed. CONCLUSIONS: EndoBinder presented satisfactory tissue reaction; it was biocompatible when tested in subcutaneous tissue of rats.

Color and opacity of composites protected with surface sealants and submitted to artificial accelerated aging.

OBJECTIVES: To evaluate the color similarity, stability and opacity of composites (TPH, Charisma, and Concept, shade A2) protected with surface sealants (Fortify Plus and Biscover) and cyanoacrylate (Super Bonder). METHODS: Forty specimens of each composite were made and separated into 4 groups (n=10) according to the surface protection: GI - without sealant; GII - cyanoacrylate; GIII - Fortify Plus; GIV - Biscover. Color and opacity readings were taken before and after Artificial Acelerated Aging (AAA) and the values obtained for color stability were submitted to statistical analysis by 2-way ANOVA and Bonferroni's test (P<.05). The values acquired for color similarity were submitted to 1-way ANOVA and Tukey's test (P<.05). The specimen sufaces were compared before and after AAA using Scanning Electronic Microscopy (SEM). RESULTS: Studied composites did not present the same values for the coordinates L*, a* and b * before AAA, indicating that there was no color similarity among them. All composites presented color alteration after AAA with clinically unacceptable values. Protected groups presented lower opacity variation after AAA, in comparison with the control goup. SEM evaluation demonstrated that AAA increased the surface irregularities in all of the studied groups. CONCLUSION: Surface sealants were not effective in maintaining composite color, but were able to maintain opacity.

Bleaching agent action on color stability, surface roughness and microhardness of composites submitted to accelerated artificial aging.

OBJECTIVES: The purpose of this study was to evaluate the bleaching agent action on color stability, surface roughness and microhardness of composites (Charisma, Filtek Supreme and Heliomolar - A2) submitted to accelerated artificial aging (AAA). METHODS: A Teflon matrix (12 x 2 mm) was used to fabricate 18 specimens (n=6) which, after polishing (Sof-Lex), were submitted to initial color reading (ΔE), Knoop microhardness (KHN) (50 g/15 s load) and roughness (R(a)) (cut-off 0.25 mm) tests. Afterwards, the samples were submitted to AAA for 384 hours and new color, microhardness and roughness readings were performed. After this, the samples were submitted to daily application (4 weeks) of 16% Carbamide Peroxide (NiteWhite ACP) for 8 hours and kept in artificial saliva for 16 hours. New color, microhardness and roughness readings were made at the end of the cycle, and 15 days after bleaching. RESULTS: Comparison of the ΔE means (2-way ANOVA, Bonferroni, P<.05) indicated clinically unacceptable color alteration for all composites after AAA, but without significant difference. Statistically significant increase in the KHN values after AAA was observed, but without significant alterations 15 days after bleaching. For R(a) there was no statistically significant difference after AAA and 15 days after bleaching. CONCLUSIONS: The alterations promoted by the bleaching agent and AAA are material dependent.

Radiopacity evaluation of calcium aluminate cement containing different radiopacifying agents.

INTRODUCTION: The aim of this study was to evaluate the radiopacity of calcium aluminate cement (EndoBinder) with 3 different radiopacifiers (bismuth oxide, zinc oxide, or zirconium oxide) in comparison with gray mineral trioxide aggregate (GMTA), white MTA, and dental structures (enamel and dentin). METHODS: Eighteen test specimens of each cement with thicknesses of 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0 mm (n = 3) were made by using a stainless steel matrix and were adapted to a standardizing device (8 × 7 cm) with a graduated aluminum stepwedge varying from 2.0-16.0 mm in thickness. To compare the radiopacity of the cements with that of dental structures, slices of first molars with a thickness increasing from 0.5-3.0 mm were obtained and placed on the standardizing device. One occlusal radiograph for each tested cement was taken, with exposure time of 0.1 seconds and focus-film distance of 20 cm. Films were processed in an automatic device, and the mean radiopacity values were obtained by using a photodensitometer. RESULTS: Mean values showed that the thicker the specimen was, the greater was its radiopacity. Only EndoBinder + bismuth oxide (EBBO) and GMTA demonstrated radiopacity values greater than 3.0 mm of the aluminum scale for all thicknesses. When zinc oxide was used as radiopacifier agent, EndoBinder only reached the desired radiopacity with a thickness of 2.0 mm, and with zirconium oxide it was 2.5 mm. CONCLUSIONS: Bismuth oxide was the most efficient radiopacifier for EndoBinder, providing adequate radiopacity in all studied thicknesses, as recommended by ISO 6876, being similar to GMTA.