Introducción y Objetivo: Debido a los valores favorables sobre la resistencia de unión con elprecalentamiento del silano, en varios tipos de cerámicas, se propone evaluar los efectos del calentamientodel silano sobre la resistencia de unión al microcizallamiento de dos tipos de cementos en cerámicas de disilicato de litio. Materiales y Métodos: Fueron fabricados 48 discos de 16 mm de diámetro y 1 mm deespesor de cerámica a base de disilicato de litio (Ivoclar Vivadent, Ellwangen, Deutschland, Alemania)fueron asignados aleatoriamente en 4 grupos; GNS acido fluorhídrico 9,6%, GS acido fluorhídrico 9,6%+ aplicación de silano, GSC, ácido fluorhídrico 9,6% + aplicación de silano + secado con secador, GSHácido fluorhídrico 9,6% + aplicación de silano + secado con horno. En cada grupo (n=6) se evaluaron losdos tipos de cementos Relix ARC y Relix U2000. Los datos fueron analizados con la prueba de ANOVAde dos vías y analísis de rangos multiples con la prueba de Bonferrini. Resultados: La resistencai deunión a las fuerzas de microcizallamiento en MPA para el cemento Relyx U200 fueron: GNS- 9,3±3,46;GS- 12,4±3,20; GSS- 13,5±3,75; GSH- 12,9±4,21; y para el cemento Relix ARC: GNS- 12,1±4,89; GS-12,1±3,71; GSS- 14,4±3,33; GSH- 22,6±4,33. Conclusión: el pre-calentamiento del silano aumenta losvalores de resistencia de unión entre ambos cementos y cerámica de disilicato de litio. Abstract:Introduction and objective: The favorable values of bonding strength with the preheating of the silanein various types of ceramics, it is proposed,To evaluate the effects of heat silane on the bond strength tomicroshear two types of cements dislicato lithium ceramics. Materials and Methods: they were made48 discs of 16 mm diameter and 1 mm thick ceramic based lithium disilicate ( Ivoclar Vivadent , Ellwangen, Deutschland , Germany ) were randomized into 4 groups ; GNS hydrofluoric acid 9.6% , GS hydrofluoricacid 9.6% + silane application , GSC , 9.6% hydrofluoric acid + silane + implementation of blow-drying ,GSH 9.6% hydrofluoric acid + silane + drying application with oven, each group were made tygon twocement types each with (n = 6 ) ( Relix ARC and U200 ) . Data were analyzed with two-way ANOVA testwith post test Bonferrini. Results: for the cement Relyx ARC were: 09.3 ± 3.46 - GNS ; GS- 12.4 ± 3.20;GSS- 13.5 ± 3.75 ; GSH- 12.9 ± 4.21; and cement U200 : GNS- 12.1 ± 4.89; GS- 12.1 ± 3.71; GSS- 14.4 ±3.33; GSH- 22.6 ± 4.33 . Conclusion: preheating of the silane increases the values of bonding strengthbetween cement and ceramic lithium disilicate.

Introduction: the object of this research was to evaluate the microshearing strength of two self-etching adhesives: one-step and two-step on enamel, upon acid and microsandblasting. Methods: 40 recently pulled human third molars, which were filed down with 600 - 2500 and divided into two groups: 1) one step (n = 20); 2) two steps (n = 20); then they were divided into four subgroups, following the procedures (sa-sm: adhesive application according to the manufacturer; sa-m: upon microsandblasting and adhesive application; ca-sm: 37% phosphoric acid application and adhesive application; ca-m: microsandblasting, 37% phosphoric acid and adhesive). Then, three layers of tygon were applied on each surface. Microshearing test conducted. The data were analyzed with the D’Agostino normality test. Afterwards, the two-criteria Anova analysis was conducted and Bonferrini postest (α = 0.05). Results: for the two-step adhesive prior application of 37% phosphoric acid and/ or microsandblasting, there is no significant increase in the enamel adhesion strength values (p = 0,678). The application of 37% phosphoric acid on enamel before the one-step adhesive increases the strength values (p = 0,001). Conclusions: microsandblasting before the adhesive process does not help increase the enamel adhesion strength values; the application of phosphoric acid helps increase the enamel adhesion strength values.