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Basic science/ cosmetic dentistry training

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Indian Dental Academy: will be one of the most relevant and exciting …

Indian Dental Academy: will be one of the most relevant and exciting

training center with best faculty and flexible training programs

for dental professionals who wish to advance in their dental

practice,Offers certified courses in Dental

implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic

Dentistry, Periodontics and General Dentistry.

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  • 1. BASIC PRINCIPLESBASIC PRINCIPLES ANDAND APPLIED PHYSICSAPPLIED PHYSICS INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com www.indiandentalacademy.com
  • 2. CONTENTSCONTENTS PHYSICAL PROPERTIESPHYSICAL PROPERTIES 1.ABRASION & ABRASION RESISTANCE1.ABRASION & ABRASION RESISTANCE 2.VISCOSITY2.VISCOSITY 3.CREEP & FLOW3.CREEP & FLOW 4.COLOUR & COLOUR PERCEPTION4.COLOUR & COLOUR PERCEPTION 5.TRANSLUCENCY5.TRANSLUCENCY THERMAL PROPERTIESTHERMAL PROPERTIES MECHANICAL PROPERTIESMECHANICAL PROPERTIES 1.STRESS1.STRESS 2.STRAIN2.STRAIN 3.ELASTIC MODULUS3.ELASTIC MODULUS 4.TOUGHNESS4.TOUGHNESS 5.BRITLLENESS5.BRITLLENESS 6.RESILIENCY6.RESILIENCY 7.HARDNESS7.HARDNESS APPLIED SURFACE PHENOMENONAPPLIED SURFACE PHENOMENON CONCLUSIONCONCLUSION BIBILOGRAPHYBIBILOGRAPHY www.indiandentalacademy.com
  • 3. INTRODUCTIONINTRODUCTION  The overriding goal of dentistry is to maintain or improve theThe overriding goal of dentistry is to maintain or improve the quality of life of dental patients and this requires the replacementquality of life of dental patients and this requires the replacement or alteration of tooth structure and selection of biocompatible,or alteration of tooth structure and selection of biocompatible, long lasting , prosthetic material that can withstand most of thelong lasting , prosthetic material that can withstand most of the conditions in oral cavity. None of the materials used in dentistryconditions in oral cavity. None of the materials used in dentistry are permanent inspite of the recent advances.are permanent inspite of the recent advances.  Dentist spends most of the time in handling of dental materialsDentist spends most of the time in handling of dental materials and the success and the failure of the treatment to a large extentand the success and the failure of the treatment to a large extent depends on his ability to select and manipulate the material,depends on his ability to select and manipulate the material, hence it becomes mandatory to have a thorough knowledge ofhence it becomes mandatory to have a thorough knowledge of the properties of dental materials.the properties of dental materials. www.indiandentalacademy.com
  • 4. ABRASION AND ABRASION RESISTANCEABRASION AND ABRASION RESISTANCE  Hardness is used usually as an index of ability of a material toHardness is used usually as an index of ability of a material to resist abrasion or wear.resist abrasion or wear.  Abrasion is a complex mechanism in the oral environment thatAbrasion is a complex mechanism in the oral environment that involves an interaction among numerous factors.involves an interaction among numerous factors.  Harder material tends to be more resistant to abrasion thanHarder material tends to be more resistant to abrasion than softer material.softer material.  CLINICAL SIGNIFICANCECLINICAL SIGNIFICANCE  Excessive wear of natural teeth that opposes a denture porcelinExcessive wear of natural teeth that opposes a denture porcelin teeth will occur.teeth will occur.  The bite of the patient cannot be altered but the wear can beThe bite of the patient cannot be altered but the wear can be limited by:limited by:  Adjusting the occlusionAdjusting the occlusion  Polishing the abraded surface.Polishing the abraded surface. www.indiandentalacademy.com
  • 5. viscosityviscosity  ““It is the resistance of a liquid to flow”It is the resistance of a liquid to flow”  The study of flow characteristics of a materials is the basis ofThe study of flow characteristics of a materials is the basis of science of rheology.science of rheology.  The rheological behaviour of 4types of fluids are shown.The rheological behaviour of 4types of fluids are shown.  1.Newtonian fluid.1.Newtonian fluid.  2.Psuedo plastic fluid2.Psuedo plastic fluid  3.Dilantin fluid3.Dilantin fluid  4.Plastic fluid4.Plastic fluid  VISCOSITY (n) = T/EVISCOSITY (n) = T/E  CLINICAL SIGNIFICANCECLINICAL SIGNIFICANCE  Cements, Gypsum products, Amorphous materials, ThixotropicCements, Gypsum products, Amorphous materials, Thixotropic materials.materials.  A low viscosity and the ability to wet surface is important in theA low viscosity and the ability to wet surface is important in the use of impression materials.use of impression materials. www.indiandentalacademy.com
  • 6. DIAGRAMSDIAGRAMS www.indiandentalacademy.com
  • 7. CREEP AND FLOWCREEP AND FLOW  ““Defined as a time dependent plastic strain of a material under aDefined as a time dependent plastic strain of a material under a static load or constant stress”.static load or constant stress”.  The term flow rather than creep is commonly used in dentistryThe term flow rather than creep is commonly used in dentistry to describe the rheological properties of a material , such asto describe the rheological properties of a material , such as waxes.waxes.  Although creep can be tested under any type of stress,Although creep can be tested under any type of stress, compression is usually used to test the creep of dental materials.compression is usually used to test the creep of dental materials.  CLINICAL SIGNIFICANCECLINICAL SIGNIFICANCE  Creep may cause unacceptable deformation of a dentalCreep may cause unacceptable deformation of a dental restoration.restoration.  It may also lead to unacceptable fit of a FPD, when a cast alloyIt may also lead to unacceptable fit of a FPD, when a cast alloy with poor creep resistance is veneered with porcelain at highwith poor creep resistance is veneered with porcelain at high temperatures.temperatures. www.indiandentalacademy.com
  • 8. COLOUR AND COLOURCOLOUR AND COLOUR PERCEPTIONPERCEPTION  ““Colour is a complex phenomenon that is a psychologicalColour is a complex phenomenon that is a psychological response to a physical stimulus”response to a physical stimulus”  The three variables of colour:The three variables of colour:  1.Hue1.Hue  2.Value2.Value  3.Chroma3.Chroma  Eye is more sensitive to Green &Yellow and less sensitive to RedEye is more sensitive to Green &Yellow and less sensitive to Red &Blue.&Blue.  TRANSLUCENCYTRANSLUCENCY.. www.indiandentalacademy.com
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  • 11. Systems used to measure colour are:Systems used to measure colour are:  1.Instrumental system1.Instrumental system  Is usually through spectrometer or calorimeter.Is usually through spectrometer or calorimeter.  Spectrometer measures the intensity of light that is reflected bySpectrometer measures the intensity of light that is reflected by an object at numerous wavelengths of visible light.an object at numerous wavelengths of visible light.  Calorimeter measures light at several wavelengths.Calorimeter measures light at several wavelengths.  2.Visual technique2.Visual technique  Also known as the munsell system.Also known as the munsell system.  It involves matching the test object to the colour tab similar toIt involves matching the test object to the colour tab similar to those available in a paint store.those available in a paint store.  Each tab has hue , chroma , value numbers assigned.Each tab has hue , chroma , value numbers assigned.  In dentistry esthetic materials have their own colour tabs orIn dentistry esthetic materials have their own colour tabs or shade called shade guides.shade called shade guides. www.indiandentalacademy.com
  • 12. Shade guideShade guide  Such as ceramic shade guide to select the colour ofSuch as ceramic shade guide to select the colour of ceramic veneers, inlays or crowns to be made byceramic veneers, inlays or crowns to be made by laboratory technician.laboratory technician.  Using the shade guide one can specify the colourUsing the shade guide one can specify the colour characteristics (hue,value,chroma) and translucencycharacteristics (hue,value,chroma) and translucency to the technician who will produce the properto the technician who will produce the proper appearance in laboratory.appearance in laboratory.  CLINICAL SIGNIFICANCECLINICAL SIGNIFICANCE www.indiandentalacademy.com
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  • 15. THERMAL PROPERTIESTHERMAL PROPERTIES  THERMAL CONDUCTIVITYTHERMAL CONDUCTIVITY  It is a thermophysical measurement of how well heat isIt is a thermophysical measurement of how well heat is transferred through a material by conductive flow.transferred through a material by conductive flow.  Heat transfer through solid substace most commonly occurs byHeat transfer through solid substace most commonly occurs by means of conduction.means of conduction.  Thermoconductivity K of a substance is the quantity of heat inThermoconductivity K of a substance is the quantity of heat in calories/joules per second.calories/joules per second.  CLINICAL SIGNIFICANCECLINICAL SIGNIFICANCE  Compared with a resin based composite that has low thermalCompared with a resin based composite that has low thermal conductivity, heat is transferred more rapidly away from theconductivity, heat is transferred more rapidly away from the tooth when cold water contacts a metallic restoration because oftooth when cold water contacts a metallic restoration because of its higher thermal conductivity.its higher thermal conductivity.  These induces greater pulpal sensitivity in metal restorations.These induces greater pulpal sensitivity in metal restorations. www.indiandentalacademy.com
  • 16. THERMAL DIFFUSIVITYTHERMAL DIFFUSIVITY  It is a measure of the rate at which a body with non uniformIt is a measure of the rate at which a body with non uniform temperature reaches a state of equilibrium.temperature reaches a state of equilibrium.  It gives a better indication of the way in which a materialIt gives a better indication of the way in which a material responds to transient thermal stimuli.responds to transient thermal stimuli.  It is defined as thermal conductivity K by product of specificIt is defined as thermal conductivity K by product of specific heat Cp times the density P.heat Cp times the density P.  Typical values of thermal diffusivity in units of square centimeterTypical values of thermal diffusivity in units of square centimeter per second are as follows: pure gold – 11,800 / amalgam – 960 /per second are as follows: pure gold – 11,800 / amalgam – 960 / composite 19 – 73 / zinc phosphate – 30 / Gic – 22 / dentinecomposite 19 – 73 / zinc phosphate – 30 / Gic – 22 / dentine 18 – 26 / enamel – 47.18 – 26 / enamel – 47.  Although the thermal conductivity of Z O E is slightly less thanAlthough the thermal conductivity of Z O E is slightly less than that of dentin, its thermal diffusivity is more than that of dentinthat of dentin, its thermal diffusivity is more than that of dentin.. CLINICAL SIGNIFICANCECLINICAL SIGNIFICANCE Difference between resin and metal denture base.Difference between resin and metal denture base. www.indiandentalacademy.com
  • 17. Coefficient of thermal expansionCoefficient of thermal expansion  Is defined as change length per unit of the original length of aIs defined as change length per unit of the original length of a material when its temperature is raised to 1degree K. It ismaterial when its temperature is raised to 1degree K. It is represented as alpha.represented as alpha.  A thermal property that is important to dentist is coefficient ofA thermal property that is important to dentist is coefficient of thermal expansion.thermal expansion.  CLINICAL SIGNIFICANCECLINICAL SIGNIFICANCE  A tooth restoration may expand or contract more than the toothA tooth restoration may expand or contract more than the tooth during a change in temperature, thus there may be marginalduring a change in temperature, thus there may be marginal leakage adjacent to restoration or restoration may debond.leakage adjacent to restoration or restoration may debond.  High thermal expansion coefficient of inlay wax is susceptible toHigh thermal expansion coefficient of inlay wax is susceptible to temperature changes. Dimensional changes occur in the accuratetemperature changes. Dimensional changes occur in the accurate wax pattern when its removed and stored in cooler areawax pattern when its removed and stored in cooler area.. www.indiandentalacademy.com
  • 18. MECHANICAL PROPERTIESMECHANICAL PROPERTIES  It is defined by the laws of mechanics, that is, the physicalIt is defined by the laws of mechanics, that is, the physical science that deals with energy and force and their effects onscience that deals with energy and force and their effects on bodies.bodies.  It defines how the body responds to thermal and mechanicalIt defines how the body responds to thermal and mechanical changes.changes.  STRESSSTRESS According to GPT-8According to GPT-8 Force per unit area; a force exerted on one body that presses orForce per unit area; a force exerted on one body that presses or pushes against or tends to invert or compress another body; thepushes against or tends to invert or compress another body; the deformation caused in a body by such a force.deformation caused in a body by such a force. stress = force/areastress = force/area unit = megapascals (MPaunit = megapascals (MPa)) www.indiandentalacademy.com
  • 19. Types of stress  In general individual applied forces may be:In general individual applied forces may be:  1. Axial1. Axial  2. Shear2. Shear  3. Bending3. Bending  4. Torsional4. Torsional  All stresses however can be resolved in combination of twoAll stresses however can be resolved in combination of two basic types:basic types:  Axial –Axial –  . Tensile. Tensile  . Compressive. Compressive  ShearShear www.indiandentalacademy.com
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  • 21. Tensile & compressive stressTensile & compressive stress www.indiandentalacademy.com
  • 22. Shear stressShear stress www.indiandentalacademy.com
  • 23. StrainStrain  According to GPT – 8According to GPT – 8  Change in length per unit length when stress is applied.Change in length per unit length when stress is applied.  Regardless of the composition or nature of the material andRegardless of the composition or nature of the material and regardless of the magnitude and the type of load applied to theregardless of the magnitude and the type of load applied to the material, deformation or strain results with each stress.material, deformation or strain results with each stress.  Stress Strain Relationship:Stress Strain Relationship:  Stress and strain are closely related and may be seen as cause andStress and strain are closely related and may be seen as cause and effect.effect.  And used to characterize the properties of dental materials.And used to characterize the properties of dental materials. www.indiandentalacademy.com
  • 24. www.indiandentalacademy.com
  • 25.  Relation between stress and strain can be used to explain theRelation between stress and strain can be used to explain the following:following:  Proportional limitProportional limit  It is defined as the greatest stress a material will sustain without deviation from the linear proportionality of stress to strain.  Yield strengthYield strength  It is often used to describe the stress at which athe material begins to function in a plastic manner.  Clinical significance :Clinical significance :  Materials having high proportional limit are more likely to withstandMaterials having high proportional limit are more likely to withstand applied stresses without permanent deformation.applied stresses without permanent deformation.  High proportional limit of cobalt-chromium alloy is the reason for itHigh proportional limit of cobalt-chromium alloy is the reason for it being the reason of choice for cast partial denture.being the reason of choice for cast partial denture.  Enamel has a high yield strength compared to the restorativeEnamel has a high yield strength compared to the restorative materials used. Composites with a higher yield strength deform lessmaterials used. Composites with a higher yield strength deform less compared to unfilled plastics.compared to unfilled plastics. www.indiandentalacademy.com
  • 26.  Ultimate strengthUltimate strength  It is the ultimate stress a material can withstand in tension orIt is the ultimate stress a material can withstand in tension or compression.compression.  Fracture strengthFracture strength  The strength at which a material fractures.The strength at which a material fractures.  ElongationElongation  The deformation that results from application of tensile force.The deformation that results from application of tensile force.  It is very important because it gives an indication of workabilityIt is very important because it gives an indication of workability of an alloy.of an alloy. www.indiandentalacademy.com
  • 27. www.indiandentalacademy.com
  • 28. Elastic modulus/ youngs modulus/ modulusElastic modulus/ youngs modulus/ modulus of elasticityof elasticity  It describes the relative stiffness or rigidity of a material.It describes the relative stiffness or rigidity of a material.  It is denoted by E.It is denoted by E.  Since strain is unitless it has the unit of stress. It is usually MPaSince strain is unitless it has the unit of stress. It is usually MPa or GPa.or GPa.  1GPa = 1000MPa.1GPa = 1000MPa.  An elastic modulus increases the material becomes more rigid.An elastic modulus increases the material becomes more rigid.  Clinical significanceClinical significance  Elastomers & polymersElastomers & polymers  Metals &ceramicsMetals &ceramics  Polyether impression material have greater toughnessPolyether impression material have greater toughness  Enamel and dentineEnamel and dentine www.indiandentalacademy.com
  • 29. www.indiandentalacademy.com
  • 30. Poisson`s ratioPoisson`s ratio  It is defined as a ratio of strain which occurs in the direction of stress, toIt is defined as a ratio of strain which occurs in the direction of stress, to the strain which occurs perpendicular to the direction of stress.the strain which occurs perpendicular to the direction of stress.  Since it is a ratio of two strains it is unitless.Since it is a ratio of two strains it is unitless.  All materials change shape in three dimensions even if stress is in oneAll materials change shape in three dimensions even if stress is in one direction eg: if we bite in a restoration and apply compressive force indirection eg: if we bite in a restoration and apply compressive force in the occluso-apical direction, the filling becomes wider in mesial-distalthe occluso-apical direction, the filling becomes wider in mesial-distal and buccal-lingual direction.and buccal-lingual direction.  Poisson`s ratio lies between 0.3 to 0.5Poisson`s ratio lies between 0.3 to 0.5  Enamel – 0.33Enamel – 0.33  Amalgam – 0.33Amalgam – 0.33  Resin,composite,hybrid – 0.30Resin,composite,hybrid – 0.30  More ductile materials such as soft gold alloy, which are high in goldMore ductile materials such as soft gold alloy, which are high in gold show high degree of reduction in cross sectional area and poisson`sshow high degree of reduction in cross sectional area and poisson`s ratio.ratio. www.indiandentalacademy.com
  • 31. Ductility & MalleabilityDuctility & Malleability  Ductility is defined as the ability of a material toDuctility is defined as the ability of a material to withstand permanent deformation under a tensile loadwithstand permanent deformation under a tensile load without rupture, ability of a material to be plasticallywithout rupture, ability of a material to be plastically strained in tension.strained in tension.  Malleability is defined as capable of being extended orMalleability is defined as capable of being extended or shaped with hammer or with the pressure of rollers,shaped with hammer or with the pressure of rollers, ability of a material to sustain considerable permanentability of a material to sustain considerable permanent deformation without fracture under compression.deformation without fracture under compression.  ExamplesExamples www.indiandentalacademy.com
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  • 33. Brittleness , Toughness & ResiliencyBrittleness , Toughness & Resiliency  According to GPT-8According to GPT-8  Brittleness –The fracture that occurs when proportional limitBrittleness –The fracture that occurs when proportional limit of the material is exceeded.of the material is exceeded.  Toughness – Ability of a material to withstand stress andToughness – Ability of a material to withstand stress and strain without breaking.strain without breaking.  Resiliency – Capable of withstanding shock withoutResiliency – Capable of withstanding shock without permanent deformation or rupturepermanent deformation or rupture www.indiandentalacademy.com
  • 34. www.indiandentalacademy.com
  • 35. HardnessHardness  ““In most metallurgy and most other disciplines the concept ofIn most metallurgy and most other disciplines the concept of hardness is resistance to indentation”.hardness is resistance to indentation”.  Properties that are related to hardness of a material are –Properties that are related to hardness of a material are – compressive strength, proportional limit & ductility.compressive strength, proportional limit & ductility.  It is measured as force per unit area.It is measured as force per unit area.  Most commonly used hardness test are-Most commonly used hardness test are-  The indenter may be made of steel, tungsten carbide or diamondThe indenter may be made of steel, tungsten carbide or diamond and may be shaped as sphere, cone, pyramid or needle.and may be shaped as sphere, cone, pyramid or needle.  Loads typically range from 0.5N to 30KN.Loads typically range from 0.5N to 30KN. www.indiandentalacademy.com
  • 36. Different hardness testDifferent hardness test www.indiandentalacademy.com
  • 37. Flexural strengthFlexural strength  The flexural strength of a material is obtained when a simpleThe flexural strength of a material is obtained when a simple beam , simply supported at both ends is subjected to a load inbeam , simply supported at both ends is subjected to a load in the middle.the middle.  Such a test is called three point bending test (3PB) and theSuch a test is called three point bending test (3PB) and the maximum stress measured is called the flexural strength.maximum stress measured is called the flexural strength.  It is also known as transverse strength or modulus of ruptuer.It is also known as transverse strength or modulus of ruptuer.  It is represented as:It is represented as:  = 3Pl/2bd square= 3Pl/2bd square  Clinical significanceClinical significance  For brittle materials such as ceramics, flexure tests are preferredFor brittle materials such as ceramics, flexure tests are preferred to the diametral compressive test because they more closelyto the diametral compressive test because they more closely simulate the stress distribution in dental prosthesis such assimulate the stress distribution in dental prosthesis such as cantilever bridge & multiple FPD`s.cantilever bridge & multiple FPD`s. www.indiandentalacademy.com
  • 38. www.indiandentalacademy.com
  • 39. FATIGUE STRENGTHFATIGUE STRENGTH  Fatigue is defined as a progressive fracture under repeatedFatigue is defined as a progressive fracture under repeated loading.loading.  Fatigue strength is the stress at which a material fails underFatigue strength is the stress at which a material fails under repeated loading.repeated loading.  Stress values are much below than the UTS can produceStress values are much below than the UTS can produce premature fracture when the material is subjected to this stress.premature fracture when the material is subjected to this stress.  ENDURANCELIMIT- For some materials a stress at which theENDURANCELIMIT- For some materials a stress at which the specimen can be loaded infinite times without failing can bespecimen can be loaded infinite times without failing can be reached.reached.  Clinical significanceClinical significance  some materials or prosthetic appliances exhibit static fatigue asome materials or prosthetic appliances exhibit static fatigue a phenomenon attributed to the interaction of a constant tensilephenomenon attributed to the interaction of a constant tensile stress with structural flaws over time.stress with structural flaws over time. www.indiandentalacademy.com
  • 40. Applied surface phenomenonApplied surface phenomenon  Tension surfaceTension surface  Also known as surface energy.Also known as surface energy.  It is the increase in energy per unit area of the surface, it isIt is the increase in energy per unit area of the surface, it is measured force per centimeter of the surface of liquid. And surfacemeasured force per centimeter of the surface of liquid. And surface tension of liquid is decreased by presence of impurities.tension of liquid is decreased by presence of impurities.  The energy at the surface of a solid is greater than that of itsThe energy at the surface of a solid is greater than that of its interior.interior.  Clinical significanceClinical significance  The surface energy of some materials like waxes and metals differ.The surface energy of some materials like waxes and metals differ. www.indiandentalacademy.com
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  • 42. WETTINGWETTING  To produce adhesion the liquid must flow easily over the entireTo produce adhesion the liquid must flow easily over the entire surface and adhere to the solid.surface and adhere to the solid.  This character is known as wetting.This character is known as wetting.  Contact angle of wetting-Contact angle of wetting-  The contact angle is the angle formed at the interface of theThe contact angle is the angle formed at the interface of the adhesive and the adherendadhesive and the adherend.. www.indiandentalacademy.com
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  • 44. AdhesionAdhesion  ““It is the bonding of dissimilar materials by the attraction ofIt is the bonding of dissimilar materials by the attraction of atoms or molecules”.atoms or molecules”.  Two mechanism of adhesion are:Two mechanism of adhesion are:  1.Chemical1.Chemical  2.Mechanical2.Mechanical  Chemical involves bonding at the atomic or molecular level.Chemical involves bonding at the atomic or molecular level.  Mechanical is based on retention by the interlocking or theMechanical is based on retention by the interlocking or the penetration of one phase into the surface of another.penetration of one phase into the surface of another.   CLINICAL SIGNIFICANCECLINICAL SIGNIFICANCE www.indiandentalacademy.com
  • 45. www.indiandentalacademy.com
  • 46.  R.D.Paravina,S.Westland,M.Kimura,J.M.Dowers,F.H.Imai,DentaR.D.Paravina,S.Westland,M.Kimura,J.M.Dowers,F.H.Imai,Denta l materials-2006,vol-22,issue no.10-12.l materials-2006,vol-22,issue no.10-12.  Blending effect of layered composites – it was found thatBlending effect of layered composites – it was found that blending effect was composite and shade dependent.It increasedblending effect was composite and shade dependent.It increased with decreased of color difference and the increase ofwith decreased of color difference and the increase of translucency parameter.translucency parameter.  M.P.Walker,R.Haj-M.P.Walker,R.Haj- Ali,Y.Wang,D.Hunziker,K.B.Williams.Department ofAli,Y.Wang,D.Hunziker,K.B.Williams.Department of Prosthdontic,University of Missouri-Kanvas,USA.Prosthdontic,University of Missouri-Kanvas,USA.  Simulation of intraoral temperature and humidity levels did notSimulation of intraoral temperature and humidity levels did not significantly decrease either the flexure modulus or flexuresignificantly decrease either the flexure modulus or flexure strength of 3 commercial composites with respect to valuesstrength of 3 commercial composites with respect to values observed when specimen were made at ambient temperature andobserved when specimen were made at ambient temperature and humidity.humidity. www.indiandentalacademy.com
  • 47.  Thomas Stober,Tanja Lutz,Herbert Glid,Department ofThomas Stober,Tanja Lutz,Herbert Glid,Department of Prosthodontics,Karls University,Heidelberg,Germany.Prosthodontics,Karls University,Heidelberg,Germany.  Dental materials-2006,Vol-22,No-1-3.Dental materials-2006,Vol-22,No-1-3.  The denture teeth examined in this study showed provenThe denture teeth examined in this study showed proven difference in two body wear bahaviour. How ever the resultsdifference in two body wear bahaviour. How ever the results donot indicate any connection between the wear resistance anddonot indicate any connection between the wear resistance and the chemical composition of the sample. For a better judgementthe chemical composition of the sample. For a better judgement of the wear behaviour of dental material in the oralcavity,of the wear behaviour of dental material in the oralcavity, additional data from 3 body wear tests and clinical studies wouldadditional data from 3 body wear tests and clinical studies would be at interest.be at interest. www.indiandentalacademy.com
  • 48. CONCLUSIONCONCLUSION  WE AS DENTIST MUST BE IN SEARCH OF MOREWE AS DENTIST MUST BE IN SEARCH OF MORE RELIABLE AND BIO-COMPATIBLE PERMANENTRELIABLE AND BIO-COMPATIBLE PERMANENT DENTAL MATERIALS . FOR THIS A MUCH DEEPERDENTAL MATERIALS . FOR THIS A MUCH DEEPER AND BETTER UNDERSTANDING OF THE PHYSICAL,AND BETTER UNDERSTANDING OF THE PHYSICAL, MECHANICAL AND CHEMICAL PROPERTIES OF THEMECHANICAL AND CHEMICAL PROPERTIES OF THE MATERIALS USED IS OF UTMOST IMPORTANCE.MATERIALS USED IS OF UTMOST IMPORTANCE. www.indiandentalacademy.com
  • 49. BIBILOGRAPHYBIBILOGRAPHY  CRAIG’S RESTORATIVE DENTAL MATERIALS 8CRAIG’S RESTORATIVE DENTAL MATERIALS 8THTH EDITION.EDITION.  JOHN F.M.C CABE APPLIED DENTAL MATERIALS 7JOHN F.M.C CABE APPLIED DENTAL MATERIALS 7THTH EDITION.EDITION.  E.C.COMBE NOTES ON DENTAL MATERIALS 6E.C.COMBE NOTES ON DENTAL MATERIALS 6THTH EDITION.EDITION.  PHILLIPS SCIENCE OF DENTAL MATERIALS 11PHILLIPS SCIENCE OF DENTAL MATERIALS 11THTH EDITIONEDITION  GLOSSORY OF PROSTHODONTIC TERMS 8GLOSSORY OF PROSTHODONTIC TERMS 8THTH EDITIONEDITION www.indiandentalacademy.com
  • 50.  R.D.Paravina,S.Westland,M.Kinura,J.M.Dowers,F.H.Imai,DentalR.D.Paravina,S.Westland,M.Kinura,J.M.Dowers,F.H.Imai,Dental Materials – 2006, vol-22, issue no.10-12.Materials – 2006, vol-22, issue no.10-12.  M.P.Walker, R.Haj-M.P.Walker, R.Haj- Ali,Y.Wang,D.Hunziker,K.B.Williams,Department ofAli,Y.Wang,D.Hunziker,K.B.Williams,Department of prosthodontics,University of Missouri –Kanvas,USA.prosthodontics,University of Missouri –Kanvas,USA.  Thomas Stober,Tanja Lutz,Herbert Glid,Departmant ofThomas Stober,Tanja Lutz,Herbert Glid,Departmant of prosthodontic,Karls-University,Heidelberg,Germany.Dentalprosthodontic,Karls-University,Heidelberg,Germany.Dental materials-2006,vol-22,no.1-3.materials-2006,vol-22,no.1-3. www.indiandentalacademy.com
  • 51. Thank you For more details please visit www.indiandentalacademy.com www.indiandentalacademy.com

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