statement of problem: the restoration of the teeth should have enough ability to withstand masticator forces while preserving as much tooth structure as possible. purpose: the purpose of this study was to compare the effects of light-heat cured composite with light cured composite restorations on fracture resistance of the restored teeth. materials and methods: forty healthy maxillary premolar ...

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...

polymerization contraction may produce defects in the composite - tooth bond. this may lead to bond failure and microleakage. the aim of this study was to reduce microleakage of posterior composites using different methods. 45 molar and premolars extracted teeth were choosen. the cavities were randomly assigned into 5 groups of 9. box-shaped cavities were prepared on each side of proximal surfa...

OBJECTIVE To determine the effect of delayed light polymerization of a dual-cured composite base material on the marginal adaptation of class II composite restoration. MATERIALS AND METHODS 35 extracted human molar teeth were used to prepare class II mesio-occlusal or disto-occlusal slot preparations with gingival margins at the CEJ. The teeth were restored using an open-sandwich technique wi...

microleakage is a major factor affecting longevity of composite restorations. this study evaluated the effect of polymerization mode of bonding agent on microleakage of composite restorations.forty-eight class v cavities were prepared on buccal and lingual surfaces of 24 extracted human premolars. occlusal and gingival margins were placed in the enamel and dentin, respectively. teeth were divid...

PURPOSE To evaluate the curing depth and compressive strength of dental composite using halogen light curing unit and light emitting diode light curing unit. MATERIALS AND METHODS Eighty cylindrical composite specimens were prepared using posterior composite P60(3M). Forty specimens, out of which 20 samples (group A) cured with halogen light and 20 samples (group B) cured using light emitting...

PURPOSE To compare contraction stresses in direct and indirect composite restorations using crack analysis. MATERIALS AND METHODS Glass disks with a central cylindrical hole were prepared. Initial cracks were made in the glass using a Vickers indenter at various distances from the edge of the hole. The indentation crack lengths were measured parallel to the tangent of the edge of the hole. Si...

statement of problem: one of the factors affecting the degree of polymerization of light-cured composites is the type of light-curing unit used. in addition, physicomechanical properties of composite resins depend on the degree of conversion and polymerization. objectives(s): since the type of initiator in new composite resins is not explained by manufacturers, this study is an attempt to compa...