Mahalaxmi - Materials used in Dentistry.pdf

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Click here to Visit - www.thedentalhub.org.in Click Here to Visit www.thedentalhub.org.in  eBook Brought to you By “ The Dental Hub ” Click Here to Visit www.thedentalhub.org.in Visit our Website for More Dental stuffs www.thedentalhub.org.in Click here to Visit - www.thedentalhub.org.in Foreword v Click Here to Visit www.thedentalhub.org.in Preface vii Acknowledgments ix Contributors xi Introduction to Dental Materials 3 Structure of Matter 8 Properties of Dental Materials 19 Light and Color 42 Metals and Alloys 63 Tarnish and Corrosion 77 Principles of Adhesion 91 Polymers in Dentistry 102 Science of Biomaterials 119 Biocompatibility of Dental Materials 129 Denture-Based Materials 149 Dental Amalgam 195 Mercury 222 Dental Cements 230 Glass Ionomer Cements 257 Composite Resins 275 Direct Filling Gold 306 Dental Casting Alloys 325 Dental Ceramics 339 Indirect Composite Resins 371 Dental Implant Biomaterials 382 Click here to Visit - www.thedentalhub.org.in xvi Table of Contents at a Glance Bonding and Bonding Agents 397 Impression Materials and Techniques 415 Gypsum and Die Materials 461 Dental Waxes 483 Click Here to Visit www.thedentalhub.org.in Investment Materials and Techniques 500 Casting Procedures 521 Finishing and Polishing 539 Antiplaque Agents 563 Materials Used for Remineralization 581 Pit and Fissure Sealants 593 Soldering and Welding 607 Orthodontic Material Science 621 Root Canal Irrigants 645 Intracanal Medicaments 656 Calcium Hydroxide 666 Root Canal Sealers 680 Materials Used for Obturation 695 Retrograde Filling Materials 708 Materials Used for Tooth Whitening 724 Local Anesthetic Agents 739 Suture Materials 760 Biomaterials Used in Periodontology 778 Bibliography 799 Index 809 Click here to Visit - www.thedentalhub.org.in Foreword v Rheological Properties 24 Click Here to Visit www.thedentalhub.org.in Preface vii Flow 24 Acknowledgments ix Creep 24 Viscosity 25 Contributors xi Viscoelasticity 25 Behavior of Liquids 25 T ixotropy 26 Mechanical Properties 26 Stress 26 Strain 28 Poisson’s Ratio 29 Introduction to Dental Materials 3 Hooke’s Law 30 Historical Perspective 3 Physicomechanical Properties 31 Selection of Dental Materials 4 Modulus of Elasticity Standards and Specifications (Elastic Modulus, Young’s Modulus) 31 for Dental Materials 5 Proportional Limit 31 Research Trends in Dental Materials 6 Elastic Limit 32 Conclusion 7 Yield Point 32 Yield Strength 32 Structure of Matter 8 Ultimate Tensile Strength 32 Atomic Structure: Fundamental Concepts 9 Ductility 32 Periodic Table 10 Brittleness 33 Interatomic Bonding 12 Resilience 33 Interatomic Primary Bonds 12 Toughness 33 Interatomic Secondary Bonds 13 Other Physical Properties 33 Bond Distance and Bond Energy 14 Malleability 33 States of Matter 14 Hardness and Hardness Testing 34 Classical States 15 Tear Strength 37 Nonclassical States 16 Transverse Strength Unit Cell 17 (Flexural Strength/Modulus of Rupture) 38 Atomic Packing Factor 17 Tensile Strength 38 Conclusion 18 Diametral Compression Test 39 Compressive Strength 39 Properties of Dental Materials 19 Wear 39 Optical Properties 20 Dimensional Change 40 Chemical Properties 20 How Alloys A ect Physical Properties 41 Solubility 20 Conclusion 41 Chemical Erosion 21 Leaching 21 Adhesive Properties 21 Light and Color 42 T ermal Properties 21 Concepts of Color Perception 43 Specific Heat 22 Light 43 T ermal Conductivity 22 Illuminant (Light Source) 43 T ermal Di usivity 23 Interaction of Light Source with an Object 46 Coe cient of T ermal Expansion 23 Reflection 46 Click here to Visit - www.thedentalhub.org.in xviii Detailed Table of Contents Refraction 46 Yield Strength 70 Transmission 47 Hardness 71 Di raction 47 Noble Metals 71 Absorption 48 Gold 71 Scattering 48 Platinum 71 Color Vision 48 Palladium 71 Color of Teeth 48 Other Noble Metals 71 Click Here to Visit www.thedentalhub.org.in Factors Influencing Color Perception 49 Base Metals 72 Repeated Viewing of Colors 49 Silver 72 Age and Sex 49 Copper 72 Surroundings 50 Zinc 72 Dimensions of Color 50 Tin 72 Hue 50 Indium 72 Chroma 50 Gallium 72 Value 50 Nickel 72 Metamerism 52 Phases of Dental Alloys 73 Fluorescence 53 Phase Diagrams 73 Additive and Subtractive Colors 53 Alloy-Strengthening Mechanisms 75 Opalescence 53 Tempering and Quenching 75 Measurement of Color 54 Age Hardening 76 Munsell System 55 Conclusion 76 CIE L*a*b System 55 Shade Selection and Natural Teeth 56 Tarnish and Corrosion 77 Dental Shade Guides and Colorimeters 56 Tarnish 78 Color Matching in Clinical Practice 57 Causes of Tarnish 78 Factors Influencing Shade Selection 58 Corrosion 79 Squint Test 59 Basic Corrosion Process 79 Steps in Shade Matching 59 Causes of Corrosion 79 Dental Digital Photography and Color 61 Factors A ecting Corrosion 79 Conclusion 62 Classification of Corrosion 80 Chemical/Dry Corrosion 80 Metals and Alloys 63 Electrochemical/Electrolytic/Wet Periodic Table 64 Corrosion 80 Atomic Structure of Metals 64 Biological Corrosion 84 Unit Cell and Lattice Structure 64 Tarnish and Corrosion Grains and Grain Boundaries 65 of Dental Restorations 85 Metallic Bonds 65 Tarnish and Corrosion Properties of Metals 65 of Restorative Materials 85 Physical Properties 65 Noble Metal 85 Chemical Properties 66 Base Metal Alloys 85 Mechanical Properties 66 Stainless Steel 86 Solidification of Metals 67 Amalgam 86 Nucleus Formation 68 NiTi Alloys 87 Alloys 68 Dental Amalgam Restoration Classification of Alloys 69 and Crevice Corrosion 87 Solid Solutions 69 Evaluation of Tarnish Types of Solid Solutions 69 and Corrosion Resistance 87 Phases of Alloys 70 Clinical Significance Properties of Alloys 70 of Galvanic Currents 88 Density 70 Galvanic Shock 88 Liquidus and Solidus 70 Biocompatibility Issues 89 Click here to Visit - www.thedentalhub.org.in Detailed Table of Contents xix Protection Against Corrosion 89 Termination 109 Conclusion 89 Inhibition of Polymerization 109 Applications of Resins in Dentistry 109 Principles of Adhesion 91 Unfilled Resins 109 Concept of Adhesion in Dentistry 92 Direct Filling Resins 112 Adhesion Between Solids 92 Maxillofacial Prosthetic Materials 112 Adhesion Between Solid and Liquid 92 Denture Teeth and Acrylic Facings 113 Click Here to Visit www.thedentalhub.org.in Criteria for Adhesion 93 Temporary Crown and Bridge Materials Substrate 93 (Temporization Material) 113 Wettability 93 Resinous Die Materials 114 Surface Energy 94 Other Applications in Dentistry 115 Viscosity 95 Adverse E ects of Dental Polymers 116 Surface Roughness 95 Conclusion 116 T eories of Adhesion 96 Mechanical Adhesion T eory 96 Adsorption Adhesion (Chemisorption) T eory 96 Di usion Adhesion T eory 97 Electrostatic Adhesion T eory 97 Failure of Adhesion 97 Science of Biomaterials 119 Clinical Considerations 98 Ideal Requirements of a Biomaterial 120 Clinical Applications 98 Surface Characteristics of Biomaterials 120 Factors A ecting Adhesion 98 Classification 121 Adhesion Between Dental Materials Bioinert Biomaterials 121 and Tooth Substrate 99 Bioactive Biomaterials 121 Bond Strength Test Methods 100 Bioresorbable Biomaterials 121 Macrobond Strength Tests 100 Biomaterial–Tissue Interaction 121 Microbond Strength Tests 100 Biomaterials for Dental Applications 122 Conclusion 101 Metals 123 Ceramics 123 Polymers in Dentistry 102 Polymers 124 Ideal Properties of Dental Polymers 102 Natural Materials History 103 (Biomimetic Materials) 125 Classification of Polymers 103 Reinforced Materials 126 Physical Properties of Polymers 104 Biocompatibility 127 Deformation and Recovery 104 Tissue Engineering 127 Solvation Properties 105 Requirements of a Sca old Material 127 T ermal Properties 105 Conclusion 128 Chemistry of Polymers 105 Polymerization Reaction 106 Biocompatibility of Addition Polymerization/Chain Dental Materials 129 Reaction 106 Adverse E ects of Dental Materials 130 Condensation Polymerization Systemic Toxicity 130 (Step-Growth Polymerization) 106 Local Toxicity 130 Copolymerization 107 Allergic Reactions 131 Significance of Copolymerization 107 Other Reactions 131 Cross-Polymerization 107 Methods for Evaluation Chemical Stages of Polymerization 107 of Biocompatibility 132 Induction 107 In Vitro Tests 132 Propagation 108 Animal Tests 133 Chain Transfer 109 Usage Tests 134 Click here to Visit - www.thedentalhub.org.in xx Detailed Table of Contents Ethical Issues Regarding Animal Methods of Relining and Rebasing 168 and Human Usage in Biocompatibility Denture Liners 169 Testing 136 Classification 169 Test Programs for the Biological Testing Properties 169 of Dental Materials 137 Tissue Conditioners 170 Linear Progression of Tests 137 Temporary/Short-Term/Treatment Nonlinear Progression of Tests 138 Resilient Liners 170 Click Here to Visit www.thedentalhub.org.in Biocompatibility Testing Standards 138 Permanent/Long-Term Resilient Drawbacks of Standards 139 Liners 171 Biocompatibility of Dental Materials 139 Repair Resins 172 Zinc Phosphate Cement 140 Materials 172 Zinc Polycarboxylate Cement 140 Denture Teeth 172 Zinc Oxide Eugenol Cement 140 Materials 173 Calcium Hydroxide 140 Custom Tray Materials 176 Glass Ionomer Cement 141 Undesirable Properties Silver Amalgam 141 of PMMA Denture Base Materials 176 Composite Resin 142 Porosities 176 Ceramics 143 Crazing 178 Dental Casting Alloys 143 Fracture Resistance 179 Wrought Alloys 143 Polymerization Shrinkage 179 Denture Base Resins 144 Radiolucency 179 Impression Materials 144 Biocompatibility 179 Endodontic Materials 145 Hypersensitivity 180 Conclusion 146 Microbial Growth 180 Resins with Enhanced Properties and Applications 180 Reinforced Denture Base Resins 180 Primers for Enhancing Metal– Polymer Adhesion 182 Denture-Based Materials 149 Soft/Flexible Dentures 183 History 150 Radiopaque Resins 184 General Uses of Denture Base Resins 151 Bisphenol A Glycidyl Methacrylate Ideal Properties of Denture Base (Bis-GMA) Resins 184 Materials 151 Hydron (Hydrogels) 184 Classification 152 Polycarbonates 184 Polymethylmethacrylate 152 Border Molding Material 184 Properties 153 Mouth Guard Materials 184 Heat-Activated Resin 154 Splints 184 Manipulation 155 Maxillofacial Materials 185 Chemically Cured Resins 162 Objectives of Maxillofacial Properties 162 Prosthesis 186 Uses 163 Ideal Requisites of Maxillofacial Manipulation 163 Materials 186 Fluid/Pour Type Resins 164 Classification of Maxillofacial Light-Activated Resin 165 Materials 186 Packaging 165 Materials Used 186 Technique 166 Denture Cleansers 190 Properties 166 Classification 190 Microwave-Polymerized PMMA 167 Immersion Denture Cleansers 190 Technique 167 Infection Control for PMMA Denture Reline Resins 168 Bases 190 Click here to Visit - www.thedentalhub.org.in Detailed Table of Contents xxi Sterilization 190 Trituration 211 Disinfection 190 Mulling 213 Conclusion 191 Undertriturated Mix, Normal Mix, and Overtriturated Mix 213 Condensation 214 Pre-Carve Burnishing 216 Carving 217 Click Here to Visit www.thedentalhub.org.in Post-Carve Burnishing 217 Dental Amalgam 195 Finishing and Polishing 217 History 196 Quality of Dental Amalgam 218 Classification of Dental Amalgam Factors Under Control of (Adapted from Marzouk, 1997) 198 the Manufacturer 218 Components of Dental Amalgam 198 Factors Under Control of Silver 198 the Operator 218 Tin 199 Failure of Amalgam Restorations 219 Copper 199 Reasons for Failure of Amalgam Zinc 199 Restorations 219 Noble Metals 199 Uses of Silver Amalgam 219 Composition of Alloys 199 Gallium Alloys 220 Low Copper Alloys (G.V. Black’s Bonded Amalgam Restorations 220 Silver–Tin Alloy or Conventional Amalgam Bonding Agents 220 Amalgam Alloys) 199 Conclusion 221 High Copper Amalgam Alloys (Copper-Enriched Alloys) 199 Mercury 222 Zinc-Containing Alloys 200 Properties 222 Manufacture of Alloy Powder 200 Manufacture of Mercury 223 Lathe-Cut Filings 200 Chemical Forms of Mercury 223 Spherical/Spheroidal/Atomized Concentration of Mercury 223 Powder 201 Mercury Toxicity 223 Particle Size 201 Mercury Exposure in Dentistry 224 Amalgamation Reaction/Setting Sources of Mercury Exposure Reaction 201 in Dental O ce 224 Symbols and Stoichiometry 201 Mercury Allergy 224 Low Copper Conventional Amalgam Symptoms of Chronic Mercury Alloys 201 Exposure 225 High Copper Admixed Alloys 203 Mercury Hygiene Recommendations High Copper Single Compositional in Dentistry 226 Alloys 203 Management of Mercury Vapor Release Elimination of g2 Phase 204 in Dental O ce 227 Properties 204 During Insertion of Amalgam 227 Strength 204 During Amalgam Finishing Dimensional Changes 206 and Polishing Procedures 228 Creep and Flow 207 During Amalgam Removal 228 Tarnish and Corrosion 208 During Instrument Sterilization 228 Self-Sealing Ability of Amalgam 209 Mercury Spills 228 Clinical Considerations Recycling Scrap Amalgam 228 of Dental Amalgam 209 Conclusion 229 Selection of Alloys 209 Mode of Supply 209 Dental Cements 230 Proportioning 209 General Properties of Dental Cements 231 Dispensing of Alloy and Mercury 211 Classification of Dental Cements 232 Click here to Visit - www.thedentalhub.org.in xxii Detailed Table of Contents Liners, Bases, and Sub-Bases 232 Commercial Mode of Supply 270 Cavity Liners 233 Manipulation 270 Cavity Bases 235 Tooth Preparation and Restoration 272 Sub-Bases 236 Durability of Glass Ionomer Luting Cements 236 Restorations 273 Temporary Restorations 238 Conclusion 274 Interim Restorations 238 Composite Resins 275 Click Here to Visit www.thedentalhub.org.in Water-Based Cements 238 Silicate Cement 238 History 276 Zinc Phosphate Cement 240 General Applications of Composites Copper Phosphate Cement 244 in Dentistry 277 Zinc Polycarboxylate Cement 245 Composition 277 Zinc Oxide Eugenol Cement 247 Resin Matrix 277 Modifications of Zinc Oxide Fillers 278 Eugenol Cement 250 Coupling Agent 280 Noneugenol Cements 251 Activator-Initiator-Accelerator Calcium Hydroxide Cements 251 Systems 280 Mechanism of Action 251 Other Components 281 Available Forms 251 Polymerization Reaction 282 Silicophosphate Cement 252 Curing Lights 282 Glass Ionomer Cement 252 Oxygen Inhibition 284 Resin Luting Cements 253 Depth of Cure 284 Composition 253 Degree of Conversion 286 Manipulation 253 Modes of Curing 286 Compomer 254 Classification of Composites 286 Mineral Trioxide Aggregate 254 Traditional Composite Resins Based Types 254 on Filler Particle Size Distribution 288 Composition 254 Properties of the Composites 289 Setting Reaction 255 Physical Properties 289 Properties and Mechanism of Action 255 Mechanical Properties 295 Clinical Applications 255 Posterior Composites 296 Some Uses of MTA Nanocomposites 297 as Dental Cement 255 Composites for Special Applications 297 Conclusion 255 Packable Composites 297 Flowable Composites 297 Glass Ionomer Cements 257 Clinical Considerations 298 Conventional Glass Ionomer Cements 257 Manipulation of Composite Resins 298 Composition 257 Placement of Composites 299 Mode of Supply 259 Configuration Factor (C-Factor) 301 Setting Reaction 259 Postoperative Sensitivity 302 Mechanism of Adhesion 262 Finishing and Polishing of Composites 302 Types 263 Repair of Composite Resin Restorations 302 Properties 263 Bonding of Composite to Alloys Modifications of Glass Ionomer and Ceramics 303 Cements 265 Failure of Composite Restorations 303 Highly Viscous Glass Ionomers 265 Conclusion 304 Metal-Modified Glass Ionomers 266 Resin-Modified Glass Ionomers 267 Direct Filling Gold 306 Compomers 269 Characteristics of Gold as a Restorative Clinical Considerations of Glass Material 307 Ionomer Cements 270 Fineness and Purity of Gold 308 Click here to Visit - www.thedentalhub.org.in Detailed Table of Contents xxiii Application of Gold in Operative Clinical Selection of Alloys 337 Dentistry 308 Conclusion 337 Classification (Based on the Mode of Supply) 309 Dental Ceramics 339 Physical Properties of DFG 309 Porcelain or Ceramics 340 Manufacture of Gold for Restorative History 340 Purposes 310 Basic Procedure in Firing of Click Here to Visit www.thedentalhub.org.in Gold Foil 310 a Ceramic Material 341 Varieties of Gold for Restorative Purposes 310 Classification of Dental Ceramics 343 Fibrous Gold/Gold Foil 310 Clinical Applications of Ceramics 343 Crystalline Gold 312 Composition 343 Other Types of Gold Foil 312 Basic Oxides 344 Supply of Gold Foils 312 Additional Oxides 344 Annealing/Degassing of Gold Foil 314 Fluxes 344 Alcohol Flame 314 Opacifiers 345 Bulk Annealing 315 Pigments 345 Condensation/Compaction of DFG 315 Ceramics for Ceramometal Objectives of Condensation 315 Restorations 345 Rationale of Condensing Gold Foil 316 Requirements of a Metal– Ceramic Factors Influencing Condensation System 346 of DFG 317 Conventional Feldspathic Porcelain 346 Technique of Compaction/Condensation Bonding of Ceramic to Metal 349 of DFG 317 Methods of Strengthening Ceramics 350 Clinical Considerations 318 Development of Residual Stresses Cavity Preparation 318 Within the Surface of the Material 351 Use of Liners and Bases 318 Interruption of Crack Propagation 352 Gold Placement and Condensation 318 All-Ceramic Materials/Systems 353 Conclusion 320 Ceramics Based on T eir Microstructural Phase 354 Ceramics Based on T eir Processing Technique 358 Fabrication of Ceramic Prosthesis 361 Conventional Powder/Liquid System 361 Dental Casting Alloys 325 Pressable/Cast Ceramic Restorations 365 History of Metals in Dentistry 326 Zirconia Core/Ceramic Buildup 367 Ideal Properties of Dental Casting Alloys 326 Selection Criteria for Dental Ceramics 367 Composition of Dental Casting Alloys 329 Longevity of Ceramic Restoration 369 Noble Metal Alloys 329 Conclusion 370 Classification of Noble Metal Alloys 330 Metal– Ceramic Alloys for Porcelain Indirect Composite Resins 371 Bonding 331 Need for IRC Restorations 371 Base Metal Alloys 334 Porcelain Versus Indirect Composite Nickel– Chromium Alloy 334 Restorations 373 Cobalt– Chromium Alloy 335 Classification of IRC 373 Titanium Alloys 335 First-Generation IRC Materials 373 Longevity of Bonding of Metals Direct– Indirect Method 374 to Ceramic/Porcelain 336 Indirect Method 374 Surface Oxide Layer 336 Properties 374 Melting Range of Alloys 336 Second-Generation IRC Materials 374 T ermal Compatibility 337 Properties 374 Click here to Visit - www.thedentalhub.org.in xxiv Detailed Table of Contents Improvements in Polymerization Classification Based on Treatment Techniques 375 of the Smear Layer 411 Nitrogen Atmosphere 375 Conclusion 414 Soft Start or Slow Curing 375 Electron Beam Irradiation 375 Impression Materials and Processing Mechanism 379 Techniques 415 Fiber Reinforcement 379 History 415 Click Here to Visit www.thedentalhub.org.in Clinical Considerations 379 Ideal Requirements of Impression Conclusion 381 Materials 417 Guidelines for a Good Impression 417 Dental Implant Biomaterials 382 Classification of Impression History 382 Materials 418 Osseointegration 383 Inelastic Impression Materials 418 Parts of an Implant 384 Impression Plaster 418 Classification of Dental Implants 385 Impression Waxes 420 Steps in Surgical Implant Placement 386 Impression Compound 423 Single-Stage Implants 386 Zinc Oxide Eugenol Impression Two-Stage Implants 386 Paste 427 Materials Used for Dental Implants 389 Elastic Impression Materials 430 Titanium and Its Alloys 389 Hydrocolloid Impression Materials 431 Iron-Chromium-Nickel– Based Nonaqueous Elastomeric Impression Alloys: Stainless Steel 389 Materials 441 Cobalt-Chromium-Molybdenum Alloy 389 Steps in Impression Making Ceramics 389 with Elastomers 452 Polymers 390 Impression Techniques 452 Surface Characteristics of an Implant 391 Disinfection of Elastomeric Roughness 391 Impressions 454 Ultrastructural Characterization 393 Preparation of Custom Tray 455 Nanotechnology in Implants 394 Fabrication Technique 456 Conclusion 394 Functional Impression Materials 457 Conclusion 458 Gypsum and Die Materials 461 Recommended Properties of Model and Die Materials 461 Materials Used for Making Models, Bonding and Bonding Agents 397 Casts, and Dies 462 Development of Adhesives 397 Gypsum (CaSO 4 2H 2O) 462 Enamel Bonding 398 Uses of Gypsum 462 Dentin Bonding 399 Gypsum Products (CaSO 4 ½H 2O) 463 Classification of Bonding Agents 399 Modifications of Gypsum 479 First-Generation Bonding Agents 399 Materials Used in Fabrication of Die 480 Second-Generation Bonding Agents 399 Type IV and Type V Gypsum 480 T ird-Generation Bonding Agents 399 Other Materials Used in Fabrication Fourth-Generation Bonding Agents 401 of Dental Die 480 Fifth-Generation Bonding Agents 405 Die Spacers 481 Sixth-Generation Bonding Agents 407 Conclusion 482 Seventh-Generation Bonding Agents 409 Current Classification of Bonding Agents 410 Dental Waxes 483 Classification Based on Adhesion History 484 Strategy 411 Uses of Waxes in Dentistry 485 Click here to Visit - www.thedentalhub.org.in Detailed Table of Contents xxv Classification of Waxes 485 Investment Materials and Composition of Waxes 485 Techniques 500 Individual Component Waxes 486 Investing and Investment Material 501 Para n Wax 486 Ideal Requirements of an Investment Beeswax 486 Material 501 Carnauba Wax 486 Components of an Investment Material 502 Microcrystalline Waxes 486 Types/Classification of Investment Click Here to Visit www.thedentalhub.org.in Gum Dammar 487 Materials 502 Synthetic Waxes and Resins 487 Setting Expansion of Investment Other Waxes 487 Material 502 Properties of Waxes 487 Normal Setting Expansion 503 Mechanical Properties 487 Hygroscopic Expansion T ermal Properties and Dimensional (Low Heat Technique) 503 Changes 487 T ermal Expansion Rheological Properties 489 (High Heat Technique) 503 Inlay Wax 489 Gypsum-/Calcium Sulfate-Bonded Ideal Requirements 489 Investment 503 Manipulation 489 Composition 503 Properties 493 Chemistry of Setting 505 Casting Wax 494 Setting Time 505 Composition 494 Expansion 505 Properties 494 Phosphate-Bonded Investments 508 Uses 494 Composition 508 Baseplate Wax or Modeling Wax 495 Chemistry of Setting 509 Ideal Requirements of Baseplate Setting Time 510 Wax 495 Expansion 510 Composition 495 Ethyl Silicate-Bonded Investment 510 Types 495 Composition 511 Uses 496 Chemistry of Setting 511 Sticky Wax 496 Expansion 511 Composition 496 General Criteria for Selection Properties 496 of Investment Materials 512 Uses 496 Strength of Investment Material 512 Utility Wax 497 Accuracy of Investment Material 512 Composition 497 Composition of Investment Material 512 Properties and Indication 497 Applications of Investment Materials 513 Disclosing Wax 497 Brazing Investments 513 Boxing Wax 497 Investing Procedures 513 Composition 497 Sprue Former/Sprue 514 Properties and Indication 498 Materials Used 514 Low-Fusing Impression Wax 498 Dimensions of a Sprue Former 514 Composition 498 Venting 515 Properties and Indication 498 Investing the Wax Pattern 515 Corrective Impression Wax Treatment of the Wax Pattern 518 (Korecta Wax, Iowa Wax) 498 Investing 518 Composition 498 Controlled Water-Added Technique 519 Properties and Indication 498 Conclusion 519 Bite Registration Wax 498 Composition 498 Casting Procedures 521 Steps of Bite Registration 498 Wax Burnout 521 Conclusion 498 Preparation of Ring Before Placement 522 Click here to Visit - www.thedentalhub.org.in xxvi Detailed Table of Contents Placement of Ring in Burnout Modification of the Abrasive Instrument 550 Furnace 522 Truing and Dressing Procedure 550 Wax Elimination 523 Polishing 550 Two-Stage Burnout Procedure 523 Health Hazards During Finishing Time Lapse Between Burnout and Polishing 550 and Casting 524 Finishing and Polishing Procedures Casting Crucibles 524 for Acrylic Dentures 552 Click Here to Visit www.thedentalhub.org.in Melting of the Alloy 524 Finishing and Polishing Procedures Flame 525 for Restorations 552 Parts of the Flame 526 Amalgam 552 Casting Machines 526 Composite Resin 552 Types of Casting Machines 526 Cast Metals 554 Divesting 527 Ceramics 556 Noble Alloys 527 Conclusion 560 Palladium-Based Alloys and Base Metal Alloys 528 Inspection and Finishing of the Casting 528 Laws of Casting 528 Casting Defects 532 Distortion 532 Surface Discoloration, Irregularities, Antiplaque Agents 563 and Roughness 533 History 564 Incomplete Castings 534 Preventive Periodontal T erapy 564 Porosity 535 Primary Prevention 564 Other Casting Defects 536 Secondary Prevention 564 Conclusion 538 Tertiary Prevention 565 Dental Plaque as a Biofilm 565 Finishing and Polishing 539 Structure and Properties of Biofilm Objectives of Finishing and Polishing 540 Communities 565 Rationale for Smooth Surface Plaque Concept—From Gingivitis of Restoration 540 to Periodontitis 566 Rationale for Finishing and Polishing 541 Clinical Importance 567 Terminology Associated with Finishing Ideal Properties of Antiplaque Agents 567 and Polishing 541 Mechanical Plaque Control 567 Abrasion 541 Toothbrushes 567 Hardness and Durability 542 Detergents/Toothpaste 568 Factors Determining Finishing Interdental Aids 569 and Polishing Procedures 542 Oral Irrigation Devices 571 Steps in Finishing and Polishing 543 Chemical Plaque Control 571 Speeds Used in Finishing and Polishing 544 Rationale for the Use of Chemical Instruments and T eir Designs 545 Mouth Rinses in Plaque Control 572 Abrasive Instrument Design 545 Classification of Antiplaque Agents 572 Abrasive Motion 545 Some Antiplaque Agents 572 Bonded Abrasives 546 Supragingival Plaque Control 572 Carbide Compounds 546 Subgingival Plaque Control 577 Diamond Finishing Points 547 Conclusion 579 Dental Stones 548 Coated Abrasive Disks and Strips 548 Abrasive-Impregnated Brushes Materials Used for and Felt Devices 549 Remineralization 581 Nonbonded Abrasives 549 Demineralization and Remineralization 581 Click here to Visit - www.thedentalhub.org.in Detailed Table of Contents xxvii Ideal Requirements of Remineralization Agents 582 Traditional Techniques in Remineralization 583 Fluorides 583 Systemic Fluoridation 583 Soldering and Welding 607 Topical Fluorides 584 Soldering 607 Click Here to Visit www.thedentalhub.org.in Sodium Fluoride 585 History 608 Stannous Fluoride 586 Types of Soldering 608 Acidulated Phosphate Components of a Soldered Joint 608 Fluoride 587 Steps in Soldering 613 Amine Fluorides 587 Factors Leading to Failure of Contemporary Techniques 589 a Soldered Joint 614 CPP-ACP (Recaldent™, Clinical Applications of Soldering GC Tooth Mousse™, in Orthodontics 615 MI Paste™) 589 Newer Developments in Soldering 616 CPP-ACFP (GC Tooth Mousse Welding 617 Plus™) 590 History 617 Beta Tricalcium Phosphate Types of Welding 617 (Clinpro™ Tooth Crème) 590 Principle of Orthodontic Welding 617 NovaMin™ 590 Steps in Welding 618 Pronamel 591 Failures in Welding 619 Enamelon™ 591 Clinical Applications 619 Xylitol 591 Conclusion 620 Conclusion 591 Orthodontic Material Science 621 Pit and Fissure Sealants 593 Metals 623 History 594 Stainless Steel 623 Pit and Fissure Morphology 594 Chrome– Cobalt Alloy 627 Types of Fissures 595 Titanium and Its Alloys 629 Ideal Requirements of Pit Gold 635 and Fissure Sealants 596 Nonmetals 636 Classification of Pit and Fissure Ceramics 636 Sealants 596 Plastics 638 Mode of Action 598 Futuristic Archwires 639 Factors Responsible for Retention Elastomers 639 of Sealants 598 Conclusion 641 Sealant Placement: Indications and Contraindications 599 Clinical Applications 601 Placement Techniques 601 Procedure for Application of a Light-Cured Sealant 601 Root Canal Irrigants 645 Procedure for Application of Purpose of Irrigation 645 a Chemically Cured Sealant 601 Factors Influencing the E cacy Failure of Pit and Fissure Sealant of Irrigants 646 Restorations 601 Classification of Irrigants 647 Extended Fissure Sealing Irrigants 648 (Fissure Blocking) 601 Distilled Water, Anesthetic Solutions, Preventive Resin Restoration 603 and Normal Sterile Saline 648 Conclusion 604 Hydrogen Peroxide 648 Click here to Visit - www.thedentalhub.org.in xxviii Detailed Table of Contents Chlorhexidine 649 Healing with Low pH (9– 10) Sodium Hypochlorite 650 Calcium Hydroxide 670 Combination Irrigation with Properties 670 Sodium Hypochlorite and Other Strength 670 Irrigants 650 Modulus of Elasticity 670 MTAD (Mixture of Tetracycline, Solubility, Disintegration, Acid, and Detergent) 652 and Microleakage 670 Click Here to Visit www.thedentalhub.org.in EDTA (Ethylene Diamine Tetra T ermal Insulation 670 Acetic Acid) 653 Biological Reaction 670 Electrochemically Activated Water 653 Biological Properties 670 Iodine Potassium Iodide 654 Classification 672 Clinical Procedure of Irrigation 654 Applications of Calcium Hydroxide 673 Conclusion 655 Calcium Hydroxide in Vital Pulp T erapy 674 Intracanal Medicaments 656 Calcium Hydroxide in Pulpotomy 675 Ideal Requirements of an ICM 657 Calcium Hydroxide in Apexification 675 Classification of ICMs 657 Calcium Hydroxide as an Intracanal Phenolic Agents 657 Medicament 675 Phenol 657 Other Applications of Calcium Camphorated Phenol 658 Hydroxide 678 Camphorated Monochlorophenol Conclusion 679 (CMCP) 658 Cresatin Mixture 658 T ymol 658 Root Canal Sealers 680 Halogens 659 Ideal Requirements of Root Iodine Compounds 659 Canal Sealer 680 Chloramine T 659 Functions of a Sealer 681 Iodine– Potassium Iodide 659 Classification 681 Sodium Hypochlorite 659 Composition 681 Nonphenolic Biocides 660 Zinc-Oxide– Based Sealer 681 Aldehydes 660 Eugenol-Containing Sealers 682 Biguanides—Chlorhexidine Non– Eugenol-Containing Sealers 687 Digluconate 660 Iodoform-Based Sealers 687 Quaternary Ammonium Iodoform Paste 687 Compounds 661 Calcium-Hydroxide– Based Sealers 688 Calcium Hydroxide 661 Calciobiotic Root Canal Sealer 688 Limitations of Calcium Sealapex 688 Hydroxide 661 Apexit ® Plus 688 Corticosteroids 662 Vitapex® 688 Antibiotics 663 Polyacrylic-Acid– Based Sealer 688 Rationale for Use as ICM 663 Polycarboxylate Cement 688 Clinical Considerations 663 Glass Ionomer Sealers 689 Technique of ICM Placement 664 Resin-Based Sealers 689 Conclusion 664 Polyvinyl-Resin– Based Sealer 689 Epoxy-Based Resin Sealers 689 Calcium Hydroxide 666 Methacrylate-Based Sealers 690 Manufacture of Calcium Hydroxide 667 Silicone-Based Root Canal Sealers 693 Mode of Action 667 Endofill 693 Healing with High pH (11– 13) RoekoSeal 693 Calcium Hydroxide 667 GuttaFlow® 693 Click here to Visit - www.thedentalhub.org.in Detailed Table of Contents xxix Clinical Considerations for Choosing Diaket 721 a Sealer 694 Epoxy-Resin– Based Materials 721 Conclusion 694 Polymethylmethacrylate Bone Cement 722 Materials Used for Obturation 695 Castor Oil Polymer 722 Ideal Requirements of Obturation Conclusion 723 Material 695 Click Here to Visit www.thedentalhub.org.in Classification 695 Materials Used for Tooth Metal Obturating Material 696 Whitening 724 Silver Points 696 History 724 Plastic Obturating Materials 696 Ideal Requirements of Bleaching Gutta-Percha 696 Materials 725 Resilon 702 Factors A ecting the Rate Paste Filling Materials 702 of Color Change 725 Iodoform 702 E ects of Bleaching Materials Biocalex 703 on Oral Tissues 726 N2 (RC2B) 703 Common Bleaching Materials 726 Mineral Trioxide Aggregate 703 Hydrogen Peroxide 726 Pediatric Obturation Materials 704 Carbamide Peroxide 727 Zinc Oxide Eugenol 705 Sodium Perborate 728 Iodoform Paste 705 McInnes Solution 728 Calcium Hydroxide 705 Types of Bleaching Procedures 730 Materials Used in Removal Vital Bleaching 730 of Gutta-Percha 705 Nonvital Bleaching 733 Chloroform (CHCl3) 706 Clinical Assessment of Tooth Eucalyptol (C10H 18O) 706 Whitening 734 Xylene 706 Facts and Prognosis of Bleaching 734 Halothane 706 Precautions When Using Bleaching Rectified Turpentine 707 Materials 734 Orange Wood Oil 707 Methods to Overcome the Conclusion 707 Complications/Drawbacks of Bleaching 735 Retrograde Filling Materials 708 Conclusion 735 Ideal Requirements of a Root-End Filling Material 708 Classification of Retrograde Materials 709 Metals and Alloys 709 Silver Amalgam Alloy 709 Other Metals 710 Cements 710 Local Anesthetic Agents 739 Zinc-Oxide-Eugenol– Based History 740 Cements 710 Physiology of Pain and LA 740 Glass Ionomer Cement 712 Local Anesthesia—Indications 741 Mineral Trioxide Aggregate 712 Local Anesthetic Armamentarium 741 Calcium-Enriched Mixture 719 Features of an Ideal Anesthetic 741 Calcium Phosphate Cement 719 Composition of LA Solutions 742 Resins 720 Classification of LA Agents 742 Composite Resins 720 T eories of LA Action 744 Compomers 720 Chemistry of LA Agents 746 Click here to Visit - www.thedentalhub.org.in xxx Detailed Table of Contents Physical Properties of LA Agents 746 History 764 pH of LA Solution 746 Ideal Requirements of Suture Concentration 747 Materials 765 pKa 747 Suture Size 766 Lipid Solubility 747 USP System 766 Protein Binding 747 EP System 767 Nonnervous Tissue Di usibility 747 Brown and Sharpe Gauge 768 Click Here to Visit www.thedentalhub.org.in Vasodilator Action 748 E ect of Suture Size on Clinical Biotransformation 748 Outcome 768 Excretion 748 Types of Suture Materials 769 E ects of LA on Systems 748 Based on the Source of Material 769 Local E ects 748 Based on Degradability/Absorbability 770 Systemic E ects 749 Based on the Number Contraindications of Local Anesthesia 750 of Filaments 771 Absolute Contraindication 750 Composition 771 Relative Contraindication 750 Basis of Suture Selection 771 Dosage of Local Anesthesia 751 Common Suture Materials 773 Calculation of Dosage 751 Suture Removal 774 Factors A ecting Dosage 751 Tissue Response to Suture Materials 774 Local Anesthetic Overdose 752 Innovations in Suturing Technology 775 Vasoconstrictors 752 Surgical Staples 775 Clinical Significance 752 Surgical Tapes 775 Chemistry 752 Adhesive Strips 775 Source 754 Fibrin Sealant 775 Classification 754 Skin Adhesives/Cyanoacrylates 776 Dose 755 Conclusion 777 Availability 755 Contraindications 755 Biomaterials Used in Clinical Actions 755 Periodontology 778 Anesthetics for Topical Application 756 Biomaterials Used in Periodontal Chemistry 756 and Implant Surgery 779 Concentration 756 Regeneration 779 Toxicity 757 Bone Replacement Grafts 779 Duration of Application 757 Mechanisms of Bone Regeneration Depth of Anesthesia 757 and Augmentation 779 Forms of Topical Anesthetics 757 Types of Graft Materials 780 EMLA 757 Membranes Used in Guided Tissue LA Toxicity—Antidote 757 and Guided Bone Regenerations 783 Reversal of Cardiomyotoxicity 757 Objectives 784 Reversal of Soft Tissue Anesthesia 758 Functions of a Membrane 784 Clinically Relevant Points 758 Materials Used for Barrier Conclusion 758 Membrane Techniques 784 Classification 785 Suture Materials 760 Nonresorbable Membranes 785 Wound Healing 761 Resorbable Membranes 786 Healing by Primary Intention 762 Materials Used for Root Coverage 787 Healing by Secondary Intention 763 Acellular Dermal Allografts 787 Rationale for Suturing 763 Laminar Bone Membranes 789 Suturing Armamentarium 763 Freeze-Dried Dura Mater 789 Click here to Visit - www.thedentalhub.org.in Detailed Table of Contents xxxi Oxidized Cellulose Mesh 789 Application of a Periodontal Root Surface Biomodification Materials 789 Dressing 793 Socket Preservation Materials 790 Periodontal Splints 793 Cyanoacrylates 790 Types of Splints 794 Local Drug Delivery Systems 790 Gum Veneers 796 Locally Delivered Drugs Used in Conclusion 797 Periodontology 790 Bibliography 799 Click Here to Visit www.thedentalhub.org.in Periodontal Dressings 792 Types of Dressings 792 Index 809 Click here to Visit - www.thedentalhub.org.in Click Here to Visit www.thedentalhub.org.in Click here to Visit - www.thedentalhub.org.in S ECTION I Click Here to Visit www.thedentalhub.org.in Fu n d a m e n ta ls o f De n ta l Ma te ria ls Ma h a la xm i S. Ka rth ike ya n K. S rin iva s a n N. Sa thya ku m a r S. Ka vith a Sa n je e v Po n s e ka r Ab ra h a m A. Ve n ka t R. Chapter 1 Introduction to Dental Materials 3 Chapter 2 Structure of Matter 8 Chapter 3 Properties of Dental Materials 19 Chapter 4 Light and Color 42 Chapter 5 Metals and Alloys 63 Chapter 6 Tarnish and Corrosion 77 Chapter 7 Principles of Adhesion 91 Chapter 8 Polymers in Dentistry 102 Click here to Visit - www.thedentalhub.org.in Click Here to Visit www.thedentalhub.org.in Click here to Visit - www.thedentalhub.org.in In tro d u ctio n to De n ta l Ma te ria ls CHAPTER Click Here to Visit www.thedentalhub.org.in 1 Chapter outline Historical Perspective Dental Materials Selection of Dental Materials Research Trends in Dental Materials Standards and Specifications for Conclusion Every tooth in a man’s head is more valuable than a diamond. Miguel de Cervantes, Don Quixote, 1605 Dentistry is an art and a branch of medical sci- ence that deals with the study, diagnosis, preven- tion, and treatment of diseases of the teeth, other Rome wa s not built in a day. parts of oral cavity, maxillofacial area, and the John Heywood, 1497– 1580 adjacent and associated structures. T ere are vari- eties of materials that are used in aiding each and T e evolution of dental materials started from every above-mentioned state. various materials that had been used for other T e science of dental materials deals with the purposes. Either the same material or the concept chemical composition, properties, manipulation, that was used for other purposes was introduced chemical reaction, mechanism of action, indica- into dentistry at di erent periods. For example, tions, contraindications, and clinical applications restorative materials have evolved over the decades of the materials used in dentistry. Since any mate- from nonesthetic materials with mechanical adhe- rial placed in contact with the human body is sion to tooth-colored materials with chemical or termed biomaterial, most of the materials used in micromechanical adhesion. T e thirst for attaining dentistry can be called biomaterials. the ideal restorative material has led to constant Materials used in dentistry can be broadly cat- evolution of materials and the associated technology. egorized under two major groups: (a) materials Materials such as gold, silver, lead, tin, plati- that will remain in intimate contact with the num, and aluminum were used as restorative oral tissues and (b) auxiliary materials that are materials in di erent periods. Many of them were used as an adjunct to the restorative materials discontinued because of their drawbacks. Lead and do not remain in direct contact with the fillings became unpopular because of their soft- oral structure. ness (even before lead poisoning was understood). Click here to Visit - www.thedentalhub.org.in 4 Section I * Fundamentals of Dental Materials Platinum was not used since it was too hard, drawbacks included high coe cient of thermal inflexible, and di cult to form into foil. expansion, high polymerization shrinkage, and Aluminum failed because of its lack of mallea- lack of color stability. In 1955, Michael Buonocore bility. In those days, restorations were made introduced the concept of bonding acrylic resin with metal foils rolled, condensed, shaped, and to teeth by acid etching. In 1962, Dr. Raphael polished in the cavity. T e fillings were left Bowen began experiments on reinforcing epoxy slightly high so that the final condensation resin with filler particles. Wilson and Kent (1971) Click Here to Visit www.thedentalhub.org.in occurred on mastication. Gold foil, though developed glass ionomer cement which bonds being processed and filled through a laborious chemically with the tooth structure. procedure, became popular since it did not cor- Dentistry as a specialty is believed to have rode, was highly malleable and ductile, had begun about 3000 bc. Modern dentistry began excellent durability, and was safe. Tin and amal- in 1728 after Pierre Fauchard published di er- gam were also popular due to low cost but were ent treatment modalities describing many types held in low regard. Moreover, tin restorations of dental restorations, including a method for oxidized easily and often warranted replacement. the construction of artificial dentures made T e first dental amalgam alloy (1800—D’ from ivory. Gold shell crowns were described by Arcets mineral cement [France]) was composed Mouton in 1746. T e first porcelain tooth mate- of bismuth, lead, tin, and mercury; it was plasti- rial was patented in 1789 by a French dentist de cized at 100°C. T e first room-temperature– Chemant. In 1885, Logan patented porcelain mixed amalgam Bell’s putty was introduced in fused to platinum post replacing the unsatisfac- 1819. In 1833, the Crawcour brothers brought tory wooden post previously used to build up amalgam (Royal Mineral Succedaneum) to the intraradicular areas of teeth. T e first ceramic United States. Amalgam has faced a lot of con- crowns were fabricated by Dr. Charles Land in troversies; its use was restricted at various peri- 1903. T e lost wax technique has been used for ods (Amalgam Wars I, II, and III). In 1843, the centuries, but its use in dentistry was not com- use of dental amalgam was declared to be a mal- mon until W.H. Taggart introduced his tech- practice by the American Society of Dental nique with the casting machine in 1907. In 1959, Surgeons (ASDS). In 1845, this society also the porcelain fused-to-metal technique was forced all of its members to sign a pledge to introduced. T e United States abandoned the abstain from using mercury-containing fillings. gold standard in 1971. Gold then became a T is was the beginning of the first dental amal- commodity freely traded in the open markets. gam war. T e war ended in 1856 with the rescis- In response to the increasing price of gold, the sion of the society. In the late 1800s, improved gold in the alloys was replaced by palladium and amalgams of Elisha Townsend, J.F. Flag, and later by platinum. When the prices of all the G.V. Black were widely used. noble metals further increased, base metal T ere has been a continued e ort on improv- alloys such as Ni-Cr were introduced. ing the properties, bonding, and esthetics of the restorative materials from time to time. During the first half of the twentieth century, silicates were the only tooth-colored esthetic materials available. Although silicates had good fluoride release, they are no longer used because they T e dentist must be aware of and understand severely erode and easily discolor. Acrylic resins the requirements, properties (biological and (polymethylmethacrylate [PMMA] based) replaced physical), performance, and applications of the the silicates during the late 1940s because of their dental materials. T e properties of the materials tooth-like appearance, insolubility in oral fluids, tend to di er in relationship to the type of use, ease of manipulation, and low cost. But their the period of use in the oral cavity, the proximity Click here to Visit - www.thedentalhub.org.in Chapter 1 * Introduction to Dental Materials 5 Dentist Clinical requirements Selection of dental material Click Here to Visit www.thedentalhub.org.in Based on Physical Biological properties Applications Performance properties and biocompatibility Figure 1.1 Selection of dental materials. of the material to the oral hard and soft tissues, di erent studies in several situations. T e den- etc. T e biocompatibility requirements also tists had di culty in choosing the right material vary according to this. for their clinical use. Hence, in order to stan- Nowadays, in most of the developed coun- dardize the testing protocols, the International tries, all-ceramic restorations are preferred to Organization for Standardization (ISO) was metal–ceramic restorations. Even if metal formed. T e seed for standardization was sowed ceramic is selected for a particular clinical situa- as early as the beginning of the twentieth century. tion, a noble metal (e.g., gold) is preferred to the Although there are many organizations that han- base metal, since it has many advantages such as dle standardization of dental materials, most of superior esthetics, better bonding, and the countries accept and follow only ANSI/ADA unmatched biocompatibility. However, in spite and ISO specification. of so many advantages of the ideal material of T e American Dental Association (ADA) choice for the particular clinical situation, the Seal of Acceptance program began in 1930. It next material in order is often used because of has become an important symbol of a dental factors such as economy or the availabil