Evaluation of cytotoxicity, antimicrobial activity and physicochemical properties of a calcium aluminate-based endodontic material

A calcium aluminate-based endodontic material, EndoBinder, has been developed in order to reduce MTA negative characteristics, preserving its biological properties and clinical applications. OBJECTIVES: The aim of this study was to evaluate the cytotoxicity, antimicrobial activity, pH, solubility and water sorption of EndoBinder and to compare them with those of white MTA (WMTA). MATERIAL AND METHODS: Cytotoxicity was assessed through a multiparametric analysis employing 3T3 cells. Antimicrobial activity against Enterococcus faecalis (ATCC 29212), Staphylococcus aureus. (ATCC 25923) and Candida albicans (ATCC 10556) was determined by the agar diffusion method. pH was measured at periods of 3, 24, 72 and 168 hours. Solubility and water sorption evaluation were performed following ISO requirements. Data were statistically analyzed by ANOVA and Tukey`s test with a significance level of 5%. RESULTS: EndoBinder and WMTA were non-cytotoxic in all tested periods and with the different cell viability parameters. There was no statistical differences between both materials (P>.05). All tested materials were inhibitory by direct contact against all microbial strains tested. EndoBinder and WMTA presented alkaline pH in all tested times with higher values of pH for WMTA (P<.05). Both materials showed values complying with the solubility minimum requirements. However, EndoBinder showed lower solubility than WMTA (P<.05). No statistical differences were observed regarding water sorption (P>.05). CONCLUSION: Under these experimental conditions, we concluded that the calcium aluminate-based endodontic material EndoBinder demonstrated suitable biological and physicochemical properties, so it can be suggested as a material of choice in root resorption, perforations and root-end filling

EVALUACIÓN DE UNA RESINA EPÓXICA EXPERIMENTAL COMO MATERIAL ALTERNATIVO PARA OBTENCIÓN DE MODELOS ODONTOLÓGICOS

El objetivo de este estudio fue comparar la fidelidad de copia y estabilidad dimensional entre modelos de resina ep&oacute;xica y modelos de yeso (Fuji Rock EP &ndash; GC Europe; Implant Stone &ndash; Polidental). Fuerealizada la impresi&oacute;n de una matriz de acero para obtener 30 espec&iacute;menes (n=10). La matriz simulaba dos piezas dentarias talladas para recibir coronas totales, sobre &eacute;stas fueron adaptados dos copings met&aacute;licos con aletas horizontales. Se evalu&oacute; al microscopio (Microscopio Measurescope, Nikon) la distancia entre el coping y la l&iacute;nea de terminaci&oacute;n de las piezas talladas (en adelante, &ldquo;desadaptaci&oacute;n vertical&rdquo;) y la distancia entre las aletas horizontales de los copings (en adelante, &ldquo;desadaptaci&oacute;n horizontal&rdquo;), las medidas obtenidas entre la matriz de acero y copings met&aacute;licos fueron consideradas como grupo control. Los copings met&aacute;licos fueron despu&eacute;s adaptados sobre los modelos de yeso y sobre la resina experimental y fue realizada la evaluaci&oacute;n al microscopio del mismo modo que el descrito anteriormente. Fueron realizadas 3 mediciones en dos tiempos (24 y 48 horas). Respecto a la desadaptaci&oacute;n horizontal, el yeso FujiRock present&oacute; una mejor estabilidad dimensional despu&eacute;s de 24 horas, ya que la desadaptaci&oacute;n fue similar estad&iacute;sticamente a la desadaptaci&oacute;n de la matriz (control) (p&gt;0,05). Despu&eacute;s de 48 horas, todos los grupos presentaron valores similares a la matriz (p&gt;0,05). Respecto a la desadaptaci&oacute;n vertical, todos los materiales presentaron diferencia estad&iacute;sticamente significante en relaci&oacute;n a la matriz (p˂0,05), sin embargo, no hubo diferencia entre los materiales evaluados (p&gt;0,05). La resina ep&oacute;xica experimental puede ser una alternativa viable para la obtenci&oacute;n de modelos odontol&oacute;gicos

In Vitro Analysis Of The Cement Film Thickness Of Two Endodontic Sealers In The Apical Region

Objectives: The objective of the present study was to evaluate in vitro film thickness of two endodontic sealers containing epoxy-resin and zinc-oxide-eugenol, respectively in the apical region of the root canal system. Materials and Methods: A total of 20 palatine roots of the first maxillary molars were submitted to instrumentation up to a #40 file by the step-back technique and irrigated with 2 ml of NaOCl after each change of file. The roots were divided at random into two groups of 10 elements; one group was sealed with the Sealer 26® cement and the other one with the EndoFill cement using the classical technique. The roots were abraded in the apical region until exposure of the filling and cut crosswise at 3 mm to obtain samples. The samples were analyzed by optic microscopy with 40X magnification. The images obtained were recorded using the Adobe Premiere 5.1® software and submitted to morphometric analysis using an integration grid that permitted the quantification of the area filled with the sealer or gutta-percha, and eventual empty spaces. Results: Statistical analysis of the data (Kruskal-Wallis test, P ≤ 0.05) revealed no significant differences between the epoxy-resin-based cement Sealer 26® (47.85%) and the zinc- oxide- eugenol-based cement EndoFill® (54.16%). Conclusion: We conclude that the two sealers tested showed a similar behavior regarding the cement film thickness in the apical region.203e9e11Barbizan, J.V., Fariniuk, L.F., Marchesan, M.A., Pécora, J.D., Sousa-Neto, M.D., Effectivenes of manual and rotatory instrumentation techniques for cleaning flattened root canals (2002) J Endod, 28, pp. 365-366Marchesan, M.A., Arruda, M.P., Silva-Sousa, Y.T., Saquy, P.C., Pécora, J.D., Sousa-Neto, M.D., Morphometrical analysis of cleaning capacity using nickel-titanium rotatory instrumentation associates with irrigating solutions in mesio-distal flattened root canals (2003) J Appl Oral Sci, 11, pp. 55-59Goldman, M., Simmonds, S., Rush, R., The usefulness of dye-penetration studies reexamined (1989) Oral Surg Oral Med Oral Pathol, 67, pp. 327-332Deitch, A.K., Liewehr, F.R., West, L.A., Patton, W.R., A comparison of fill density obtained by supplementing cold lateral condensation with ultrasonic condensation (2002) J Endod, 28, pp. 665-667Nelson, E.A., Liewehr, F.R., West, L.A., Increased density of gutta-percha using a controlled heat instrument with lateral condensation (2000) J Endod, 26, pp. 748-750Cathro, P.R., Love, R.M., Comparison of MicroSeal and System B/Obtura II obturation techniques (2003) Int Endod J, 36, pp. 876-882De Deus, G.A., Martins, F., Lima, A.C., Gurgel-Filho, E.D., Maniglia, C.F., Coutinho- Filho, T., Analysis of the film thickness of a root canal sealer following three obturation techniques (2003) Braz Oral Res, 17, pp. 119-125De Deus, G.A., Gurgel-Filho, E.D., Maniglia-Ferreira, C., Coutinho-Filho, T., The influence of filling technique on depth of tubule penetration by root canal sealer: A study using light microscopy and digital image processing (2004) Aust Endod J, 30, pp. 23-28Gençolu, N., Comparison of 6 different gutta-percha techniques (part II): Thermafil, JS Quick-Fill, Soft Core, Microseal, System B, and lateral condensation (2003) Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 96, pp. 91-95Wu, M.K., Wesselink, P.R., A primary observation on the preparation and obturation of oval canals (2001) Int Endod J, 34, pp. 137-141Georgopoulou, M.K., Wu, M.K., Nikolaou, A., Wesselink, P.R., Effect of thickness on the sealing ability of some root canal sealers (1995) Oral Surg Oral Med Oral Pathol Oral Radiol Endod, 80, pp. 338-344Wu, M.K., De Gee, A.J., Wesselink, P.R., Leakage of four root canal sealers at different thickness (1994) Int Endod J, 27, pp. 304-308Dalat, D.M., Onal, B., Apical leakage of a new glass ionomer root canal sealer (1998) J Endod, 24, pp. 161-163Antonopoulos, K.G., Attin, T., Hellqig, E., Evaluation of the apical seal of root canal fillings with different methods (1998) J Endod, 24, pp. 655-658Hasselgren, G., Tronstad, L., The use of transparent teeth in the teaching of preclinical endodontics (1975) J Endod, 1, pp. 278-280Sousa-Neto, M.D., Passarinho-Neto, J.G., Carvalho-Junior, J.R., Cruz-Filho, A.M., Pécora, J.D., Saquy, P.C., Evaluation of the effect of EDTA EGTA and CDTA on dentin adhesiviness end microleakage with different root canal sealers (2002) Braz Dent J, 13, pp. 123-128De Deus, G.A., Murad, C.F., Reis, C.M., Gurgel-Filho, E., Coutinho Filho, T., Analysis of the sealing ability of different obturation techniques in oval-shaped canals: A study using a bacterial leakage model (2006) Braz Oral Res, 20, pp. 64-69Baumgardner, K.R., Krell, K.V., Ultrasonic condensation of gutta-percha: An in vitro dye penetration and scanning electron microscopic study (1990) J Endod, 16, pp. 253-259De Deus, G.A., Coutinho-Filho, T., Reis, C., Murad, C., Paciornik, S., Polymicrobial leakage of four root canal sealers at two different thicknesses (2006) J Endod, 32, pp. 998-100

Assessment of flexural strength of two self-curing acrylic resins containing pigment

Aim: To assess the flexural strength of orthodontic acrylic resins from two different manufacturers (VIPI, OrtoCril versus Clássico, OrtoClas) by comparing pigmented resins to colorless ones. Methods: Resins of blue, yellow and green colors were studied. A total of 120 specimens were made and then divided into groups of 15 elements each, all having the same dimensions. Next, they were kept in aqueous medium until being subjected to mechanical testing. The flexural strength was tested in a universal test machine (EMIC DL 10000) in which the specimens were subjected to a gradual load until fracture occurred. Results: Pigmented resins had flexural strength values compatible with clinical use, being similar to those from colorless ones, except for OrtoClas green-colored and yellow-colored resins, which showed greater flexural strength. The OrtoClas green-colored resin was the most resistant to fracture (482.2 N), whereas the OrtoCril colorless resin was the least resistant (368.4 N). All OrtoClas resins showed higher strength values compared to OrtoCril resins of same color, except for the OrtoCril&apos;s blue-colored resin, which presented higher flexural strength than that of the other trademark. Conclusions: The use of pigments seems to have no effect on decreasing the flexural strength of self-curing acrylic resins. Therefore, pigmented resins are compatible with clinical use

Effect of staining solutions and repolishing on color stability of direct composites

OBJECTIVES: The purpose of this study was to assess the color change of three types of composite resins exposed to coffee and cola drink, and the effect of repolishing on the color stability of these composites after staining. MATERIALS AND METHODS: Fifteen specimens (15 mm diameter and 2 mm thick) were fabricated from microhybrid (Esthet-X; Dentsply and Filtek Z-250; 3M ESPE) and high-density hybrid (Surefil; Dentsply) composites, and were finished and polished with aluminum oxide discs (Sof-Lex; 3M ESPE). Color of the specimens was measured according to the CIE L*a*b* system in a refection spectrophotometer (PCB 6807; BYK Gardner). After baseline color measurements, 5 specimens of each resin were immersed in different staining solutions for 15 days: G1 - distilled water (control), G2 - coffee, G3 - cola soft drink. Afterwards, new color measurement was performed and the specimens were repolished and submitted to new color reading. Color stability was determined by the difference (&#916;E) between the coordinates L*, a*, and b* obtained from the specimens before and after immersion into the solutions and after repolishing. RESULTS: There was no statistically signifcant difference (ANOVA, Tukey's test; p>0.05) among the &#916;E values for the different types of composites after staining or repolishing. For all composite resins, coffee promoted more color change (&#916;E>3.3) than distilled water and the cola soft drink. After repolishing, the &#916;E values of the specimens immersed in coffee decreased to clinically acceptable values (&#916;E<3.3), but remained signifcantly higher than those of the other groups. CONCLUSIONS: No signifcant difference was found among composite resins or between color values before and after repolishing of specimens immersed in distilled water and cola. Immersing specimens in coffee caused greater color change in all types of composite resins tested in this study and repolishing contributed to decrease staining to clinically acceptable &#916;E values

Desensitizing bioactive agents improves bond strength of indirect resin-cemented restorations: preliminary results

OBJECTIVE: The aim of this study was to assess the bond strength of indirect composite restorations cemented with a resin-based cement associated with etch-and-rinse and self-etching primer adhesive systems to dentin treated or not with a bioactive material. MATERIALS AND METHOD: Twenty bovine incisor crowns had the buccal enamel removed and the dentin ground flat. The teeth were assigned to 4 groups (n=5): Group I: acid etching + Prime & Bond NT (Dentsply); Group II: application of a bioactive glass (Biosilicato®)+ acid etching + Prime & Bond NT; Group III: One-up Bond F (J Morita); Group IV: Biosilicato® + One-up Bond F. Indirect composite resin (Artglass, Kulzer) cylinders (6x10mm) were fabricated and cemented to the teeth with a dual-cure resin-based cement (Enforce, Dentsply). After cementation, the specimens were stored in artificial saliva at 37ºC for 30 days and thereafter tested in tensile strength in a universal testing machine (EMIC) with 50 kgf load cell at a crosshead speed of 1 mm/min. Failure modes were assessed under scanning electron microscopy. Data were analyzed statistically by ANOVA and Tukey's test (95% level of confidence). RESULTS: Groups I, II and III had statistically similar results (p>0.05). Group IV had statistically significant higher bond strength means (p<0.05) than the other groups. The analysis of the debonded surfaces showed a predominance of adhesive failure mode for Group III and mixed failure mode for the other groups. CONCLUSION: The use of desensitizing agent did not affect negatively the bonding of the indirect composite restorations to dentin, independently of the tested adhesive systems