Effect of ozone gas application on the mechanical properties of dental adhesives bonded to dentin.

OBJECTIVES: To assess the effect of ozone gas on the mechanical properties of different classes of dental adhesives. METHODS: Extracted molars were sectioned perpendicularly to their long axis for obtaining dentin slices to be bonded with one of the following adhesives: Prime&Bond NT (Dentsply), Excite (Ivoclar-Vivadent), Syntac/Heliobond (Ivoclar-Vivadent) and Silorane System Adhesive (3 M-ESPE). Prior to bonding, the slices were sectioned in two halves: one was treated with ozone gas for 120 s (4.2g/m3; HealOzone, KaVo) and the other served as control. The Vicker's hardness (VH), elastic modulus (E), elastic work (We/Wtot) and the creep (Cr) of the materials were measured with an automatic micro hardness indenter (Fischer) 30 min and 24 h after bonding procedure. Data were analyzed with the multivariate ANOVA followed by the Tukey's test and partial eta-squared statistics. RESULTS: The adhesive and the time of testing were significant factors affecting the investigated parameters (por=0.06). Dentin treatment, though significant, exerted a minimal effect on mechanical properties (etap2