Shrinkage, stress, and modulus of dimethacrylate, ormocer, and silorane composites.

Purpose: to evaluate the shrinkage, polymerization stress, elastic and bulk modulus resulting from composites formulated by siloranes, 2(nd) generation ormocers, and dimethacrylates.

Materials And Methods: The bonded disc method was used to evaluate volumetric shrinkage. The polymerization stress was evaluated by mean of the Bioman.

The effect of time between handling and photoactivation on self-adhesive resin cement properties.

Purpose: To evaluate the degree of conversion, absorption, and solubility in water of self-adhesive resin cements subjected to different time intervals between material preparation and the photoactivation procedure.

Materials And Methods: Two dual self-adhesive resin cements were tested: RelyX Unicem and SmartCem2. The degree of conversion as a function of time was evaluated by Fourier-transformed infrared spectroscopy using the attenuated total reflectance technique.

Do new matrix formulations improve resin composite resistance to degradation processes?

The aim of this study was to determine the degradation resistance of three new formulations-silorane-, Ormocer- and dimer-acid-based materials-and compare them to the traditional dimethacrylate-based materials. One silorane- (Filtek P90, P90), one Ormocer- (Ceram-X, CX), one dimer-acid- (N'Durance, ND) and two dimethacrylate-based (Filtek P60, P60; Tetric Ceram, TC) materials were investigated. Water sorption (Wsp) and solubility (Wsl) were determined after the materials were immersed in water for 28 days.