statement of problem: there are controversial reports regarding physical and mechanical properties of resin composites and glass ionomer cements. some revealed higher strength and hardness for resin composites while others showed a comparable value for glass ionomer cements. evaluation of mechanical properties of different types of resin composites in comparison with resin modified glass ionome...

statement of problem: resin composites are a common type of tooth coloured restorative materials. these materials are brittle and their major shortcomings are sensitivity to flaws and defects, low tensile strength, and susceptibility to catastrophic failure.the role of home bleaching agents on the fracture toughness of resin composites using four-point bending test is scanty. objectives: to com...

statement of problem: the degree of conversion depends on the material composition, light source properties, distance from light source, light intensity, curing time, and other factors such as shade and translucency. objectives: in the present study, we evaluated the effects of different light- curing modes and shades of methacrylate and silorane-based resin composites on the degree of conversi...

statement of problem: tooth-coloured restorative materials are brittle with the major shortcomings of sensitivity to flaws and defects. although various mechanical properties of resin composites have been studied, no fracture toughness test data for nano-hybrid composites under acidic condition for a long period of time has been published. objectives: to compare the fracture toughness (k ic ) o...

STATEMENT OF PROBLEM The degree of conversion depends on the material composition, light source properties, distance from light source, light intensity, curing time, and other factors such as shade and translucency. OBJECTIVES In the present study, we evaluated the effects of different light-curing modes and shades of methacrylate and silorane-based resin composites on the degree of conversio...

statement of problem: accumulation of plaque and staining due to a rough surface,  and  penetration  of  colourant  agents  from  food  and  beverages  in to the resin composite results in an incomplete polymerization. there is a little information on the effect of finishing and polishing techniques on the discoloration of nanohybrid and microhybrid composites when exposed to staining solutions...

abstract   statement of problem: hertzian indentation test has been proven to be an efficient and reliable alternative upon vickers hardness test. this method has been used to test dental ceramics, amalgams, glass ionomers and luting cements.there is limited published information about the load-bearing capacity of resin composites using hertizian indentation test. objectives: to investigate the...

STATEMENT OF PROBLEM Resin composites are brittle materials and their major shortcomings are manifested in their sensitivity to flaws and defects. Although various mechanical properties of resin composites have been described, few studies are available on assessing the effect of bleaching agents on resin composites using the short rod design. PURPOSE To place various resin composites into dis...

statement  of  problem:  patients’ demand  for  tooth-colored  restoratives  in the posterior region is increasing. clinicians use universal nanohybrid resin composites for both anterior and posterior regions. there are few published reports comparing fracture toughness of nonohybrids and that of hybrid composite stored wet and dry. objectives: to investigate the fracture toughness of three nan...