UNLABELLED Indirect resin composites are generally regarded to have better color stability than direct resin composites since they possess higher conversion degree. OBJECTIVE The present study aimed at comparing the changes in color (ΔE) and color coordinates (ΔL, Δa and Δb) of one direct (Estelite Sigma: 16 shades) and 2 indirect resin composites (BelleGlass NG: 16 shades; Sinfony: 26 shades...

OBJECTIVES The aim of the study was to develop a new kinetic model for the shrinkage-strain rates of dental resin composites. The effect of filler content on the shrinkage-strain kinetics and degree of conversion of dental composites was also investigated. METHODS A resin matrix containing 65 wt.% Bis-GMA and 35 wt.% TEGDMA was prepared. 0.5 wt.% camphorquinone and 0.5 wt.% dimethyl aminoethy...

statement of problem: ceramics as in ceramo-metallic and all ceramic tooth restorations have grown popular owing to their high tissue compatibility and esthetic advantages. such restorations have the capability to deliver valuable services over a long period of time; however, failures under intraoral conditions are not unanticipated. purpose: the purpose of this in-vitro study was to investigat...

abstract statement of problem: there is no enough published data about the shear bond strength of resin modified glass ionomer adhesives on caries-affected primary tooth dentin excavated using minimally invasive systems. objectives: to evaluate the shear bond strength of 2 different adhesives (one resin modified glass ionomer and one resin) using two caries removal techniques on healthy and car...

this research investigates the effect of the post-cure time on the residual stresses in laminated composites. laminated composites were made of t300 carbon fibers and epoxy resin. the post-cure process was carried out at the constant temperature of 120 °c for 6 and 12 hours for two specimens. the slitting method was employed to determine through-thickness residual stress distribution of the com...

OBJECTIVES To evaluate the shrinkage-strain, degree of conversion (DC) and percent filler of a range of flowable resin-composites. METHODS Several commercially available flowable resin-composites were selected. The bonded-disk technique was used to measure shrinkage-strain kinetics. Measurements were obtained continuously for 60min by irradiation for 40s at 750mW/cm(2) at two initial temperat...

Introduction:Discoloration of the resin-based composites is a common problem in restorative dentistry. There are many factors associated with the discoloration of dental materials in the oral environment. The purpose of this study was to evaluate the color changes in a nano-composite cured with a quartz-tungsten-halogen (QTH) and light emitting diode (LED) unit. Methods:80 disk-shaped specim...

objective: adverse surface interactions between one-bottle adhesives and chemical-cured composites may occur with delayed light activation of light-cured composites. the purpose of this study was to assess the effects of delayed activation of light-cured composites on shear bond strength of two one-bottle adhesives with different acidity to bovine dentin. materials and methods: flat dentin surf...

OBJECTIVES To test the null hypotheses that photoactive resin composites containing a Type I photoinitiator would exhibit reduced DC or increased monomer elution at substantially short curing times compared with materials based on a Type 2 ketone/amine system. METHODS Two experimental resin composites were prepared, using either Lucirin-TPO or camphorquinone/DMAEMA. Specimens were light-cured...