32 SERIES (VIDEO NO 44)

hello everyone this is dr. Amiya in this 32 series we are going to discuss some important points from the topic of restorative resins phone number one in heat cube the monomer consists of unpolymerized methyl methacrylate hydroquinone the inhibitor glycol limit acrylate the cross-linking agent number two the polymer powder consists of pre polymerized bits of poly methyl methacrylate and benzoyl peroxide s as in treated number three self cure has same composition accepted the liquid consists of dimethyl Perito lead in the activator which is returned sherry MN number for boiling point of monomer is 100.8 degree Celsius number five in light activated composites camphor aqua nam is initiator and dial tone is the accelerator number six in chemically activated composites benzoyl peroxide is in cheetah and dairy she area mine is the activator number seven polymerization of bencher base is an exothermic reaction number eight hydroquinone is the inhibitor which prevents the polymerization of liquid during storage number nine polymer monomer interaction proceeds in sandy stringy stuff like elastic and stiff stages in this duff stage is ideal for packing number ten plastic or Teflon coated instruments should be used with composites number eleven benzoin methyl ether is the activator in you may like curing system number twelve the optimal polymer is to an excess of monomer leads to increased polymerization shrinkage on number 13 37 percent phosphoric acid is used as an etchant concentration above 50 percent results in formation of monocalcium phosphate monohydrate which prevents further dissolution this agent is supplied in a gel form to ello control over the area of placement number 14 glycol dimethyl fellate which is a cross-linking agent has two double bonds whereas methyl methacrylate has single-bond number 16 configuration factor that is the c factor means bonded surface been unbounded surfaces number 17 the higher bc factor greater is the potential for bond disruption number 18 for Potts tungsten light pure device optimal output energy is four hundred to eight hundred millivolts per square centimeter number nineteen the minimum output energy should not be Lizzie hundred milli watt per square centimeter number twenty chemically activated resist display three to five percent free monomer whereas heat activated resins exhibit 0.2 to 0.5% of free monomer number twenty one for each one percent increase in weight produced by the water absorption acrylic resin expands 0.23 percent linearly number twenty two modulus of elasticity of polymethyl methacrylate e's twenty two point four gigapascals number twenty-three the molecular weight of monomer is hundred number 24 the density of monomer is zero point zero four five gram per milliliter at 20 degrees Celsius number twenty-five the heat of polymerization of monomer is twelve point nine kilo calorie per mole number twenty-six the volumetric shrinkage during polymerization of monomer is two point one percent number twenty seven a small molecule added to lower the glass transition temperature of a polymer is known as plasticizer number twenty eight polymer to monomer ratio is same for both heat activated and chemically activated resins number twenty nine the ratio of polymer to monomer is 3 is to 1 by volume and 2 is to 1 by weight number 30 using threes to one ratio the volumetric strain gage can be limited to approximately seven percent number 31 the time required for the resin mixture to reach the flood stage is termed as the forming time number thirty-two for composites the light curing units are designed to emit light within the range of 400 to 500 that's it for today's session guys all the points discussed in this series are very important from neat and aims point of view so keep on revising these points all the best thank you