to evaluate the ultimate compressive strength of five composite resins after 1 hour, 24 hours, 7 days and 1 month. twenty four cylindrical 4 mm×8mm specimens of each commonly used composite resins in posterior region (nulite-f , z250 , p60, biscore, tetric ceram hb) were prepared. each group of composite resins were divided into four time groups of 1 h, 24 h, 7 days and 1 month. all of specimen...

objectives: composite restorations must have tooth-like optical properties namely color and translucency and maintain them for a long time. this study aimed to compare the effect of accelerated artificial aging (aaa) on the translucency of three methacrylate-based composites (filtek z250, filtek z250xt and filtek z350xt) and one silorane-based composite resin (filtek p90). materials and methods...

Effects of abrasive and fiber components in a medium on the wear behavior of composite resins were evaluated. Calcium diphosphate and methyl cellulose were included in the medium as abrasive and fiber components respectively. A range of 0, 4, or 8% abrasive- or fiber-containing media were applied on a composite resin specimen during a simulated occlusal wear test. Four composite resins, Clearfi...

statement of the problem addition of metallic nano-particles to composite resins can change their water contact angle purpose the aim of this study was to evaluate the effect of addition of nano-particles of silver and zinc oxide to composite resins on their water contact angle materials and methods this in vitro study was performed on 60 composite resin samples. nano-silver and nano-zinc oxide...

Composite resins were reinforced with glass and polyethylene fibers in this study, and the effect of fiber reinforcement on the color change of composite resins was investigated. After accelerated aging, the effect of fiber reinforcement on the color stability of composite resins was also examined. There were three experimental groups (n=12 disks per group): non-fiber-reinforced composite (non-...

background: the purpose of this in vitro study was to evaluate surface discoloration of three microhybrid composite resins (esthet•x hd, clearfi l ap-x, gradia direct) and fi ve nanohybrid composite resins (ceram•x, gc kalore, g-aenial, grandio, grandioso), after staining and bleaching procedures. materials and methods: the composite resins were polymerized with a curing light (celalux ii, voco...

tooth fracture is a common dental problem. by extension of cavity dimensions, the remaining tooth structure weakens and occlusal forces may cause tooth fracture. the aim of this study was to evaluate and compare the fracture resistance of teeth restored with direct and indirect composite restorations.sixty-five sound maxillary premolar teeth were chosen and randomly divided into five groups eac...

objectives: this study sought to compare the push-out bond strength of two bulk-fill and one conventional composite to intracanal dentin in primary anterior teeth. materials and methods: this in vitro, experimental study was conducted on 39 primary anterior teeth, which were randomly divided into three groups. after cleaning and shaping, the root canals were filled with metapex in such a way th...

introdouction: bleaching has become a common treatment for improving the appearance of natural teeth. however, the need to protect dental restorations from bleaching agent exposure is inevitable, as these agents may change the color of restorative materials by oxidation. filtek p90 composite resin has recently been introduced with the aim of decreasing polymerization shrinkage. the purpose of t...