Avaliação da resistência ao cisalhamento de sistemas adesivos autocondicionantes para diferentes formas de tratamento de dentina / Evaluation of shear resistance of a self-etch system for different forms of dentin treatment

Introdução - O presente estudo avaliou a resistência adesiva do adesivo Clearfil SE Bond (Kuraray), quando aplicado à dentina tratada com diferentes agentes condicionadores e em dois períodos de tempo de armazenamento, usando terceiro molares humanos recém-extraídos. Material e métodos - Os dentes foram divididos aleatoriamente em 6 grupos: grupo 1 - Clearfil SE Bond usado como recomenda o fabricante e armazenado por 24 hs; grupo 2 - Clearfil SE Bond associado ao ácido poliacrílico armazenado por 24 hs; grupo 3 - Clearfil SE Bond associado ao EDTA e armazenado por 24 hs; grupo 4 - Clearfil SE Bond usado como recomenda o fabricante e armazenado por 6 meses; grupo 5 - Clearfil SE bond associado ao ácido poliacrílico e armazenado por 6 meses e grupo 6 - Clearfil SE Bond associado ao EDTA e armazenado por 6 meses. Após o preparo da dentina foi construído sobre a área de adesão um cilindro de resina composta Z250 (3M/ ESPE). Os corpos de prova foram submetidos ao teste de cisalhamento em máquina de ensaio universal Kratos com velocidade de 0,5 mm/ min. Resultados - Os valores médios encontrados em MPa foram: G1= 29,91±5,84; G2= 31,66±6,44; G3= 33, 84±4,87; G4= 29,11±9,52; G5= 27,20±7,64 e G6= 31,45±7,19. Foi utilizado o teste ANOVA através do teste F (P<0,05), não se observou diferença estatística significante entre os grupos. Conclusões - Concluiu-se que a utilização de substâncias condicionadoras associadas ao adesivo Clearfil SE Bond não interferiu na resistência adesiva e que não houve redução da resistência adesiva após o período de 6 meses.

Introduction - The present study assessed the bond strength of Clearfil SE Bond (Kuraray), when applied to dentin treated with different conditioning agents and two periods of storage time,using recently extracted human third molars. Material and methods - The teeth were randomly divided into six groups: Group 1- Clearfil SE Bond used according to the manufacturer’s recommendations and stored for 24 h; Group 2- Clearfil SE Bond associated to polyacrylic acid and stored for 24 h; Group 3- Clearfil SE Bond associated to EDTA and stored for 24 h; Group 4- Clearfil SE Bond used according to the manufacturer’s recommendations and stored for six months; Group 5- Clearfil SE Bond associated to polyacrylic acid and stored for six months; Group 6- Clearfil SE Bond associated to EDTA and stored for six months. After the preparation of the dentin, a composite resin cylinder was constructed over the adhesion areaZ250 (3M/ ESPE). Results - The specimens were submitted to the shear bond test using the Kratos universal testing machine at a velocity of 0.5 mm/min. The mean values in MPa were:G1= 29.91±5.84; G2= 31.66±6.44; G3= 33.84±4.87; G4= 29.11±9.52; G5= 27.20±7.64 and G6= 31.45±7.19. ANOVA with the F test (p<0.05) revealed no statistically significantdifferences between groups. Conclusion - It was concluded that the use of conditioning substances associated to the Clearfil SE Bond adhesive did not affect bond strength and there was no reduction in bond strength after a period of six months.

Arsenic content in Portland cement: A literature review.

Portland cement (PC) is a hydraulic binding material widely used in the building industry. The main interest in its use in dentistry is focused on a possible alternative to mineral trioxide aggregate (MTA) because PC is less expensive and is widely available. In dentistry, PC has been used in dental procedures such as pulpotomy, pulp capping, repair of root perforation and root-end filling. The purpose of this article is review the dental literature about the PC, its composition with special attention to arsenic content, properties, and application in dentistry. A bibliographic research was performed in Bireme, PubMed, LILACS and Scopus data bases looking for national and international studies about the PC composition, properties and clinical use. It was observed that PC has favorable biological properties very similar to those of MTA. The PC has shown good cell proliferation induction with formation of a monolayer cell, satisfactory inflammatory response, inhibitory effect of prostaglandin and antimicrobial effect. Studies have shown that PC is not cytotoxic, stimulates the apposition of reparative dentin and permits cellular attachment and growth. Regarding arsenic presence, its levels and release are low. PC has physical, chemical and biological properties similar to MTA. Arsenic levels and release are low, therefore, unable to cause toxic effects.