Luting Agents and Cementation Procedures PDF

LUTING AGENTS AND C E M E N TAT I O N P R O C E D U R E S D R. A D H A M N I YA Z I CHAPTER 31 Luting Agents and Cementation procedures Pages 909-927 C E M E N TAT I O N Cement: a material that on hardening will fill a space or bind adjacent objects Cementation: the process of attaching pa...

LUTING AGENTS AND C E M E N TAT I O N P R O C E D U R E S D R. A D H A M N I YA Z I CHAPTER 31 Luting Agents and Cementation procedures Pages 909-927 C E M E N TAT I O N Cement: a material that on hardening will fill a space or bind adjacent objects Cementation: the process of attaching parts by means of cement Luting agent: any material used to attach or cement indirect restorations to prepared teeth OUTLINE Ideal properties Classifications Types of cement Comparisons of luting agents Procedure techniques OUTLINE Ideal properties Classifications Types of cement Comparisons of luting agents Procedure techniques IDEAL PROPERTIES Adhesion to restorative material Adequate strength to resist functional forces Lack of solubility in oral fluids Low film thickness Biocompatible Possession of anicariogenic properties Radio-opaque Ease of manipulation Esthetic and color stable OUTLINE Ideal properties Classifications Types of cement Comparisons of luting agents Procedure techniques  C L A S S I F I C AT I O N According to ingredients: Water Based Oil Based Resin Based -Glass Ionomer -Zinc Oxide -Composite Cement Eugenol -Adhesive -Resin Modified -Zinc Oxide Resins Glass Ionomer Non-Eugenol -Compomer -Zinc Polycarboxylate -Zinc  C L A S S I F I C AT I O N According to function: Function Cement Zinc Phosphate, Zinc Polycarboxylate, Definitive Cement Composite Resin, Glass Ionomer Temporary Cement Zinc Oxide Eugenol/Non-Eugenol Zinc Phosphate, Zinc Polycarboxylate, High Strength Composite Resin, Glass Ionomer Low Strength Zinc Oxide, Calcium Hydroxide Temporary Filling Zinc Oxide, Zinc Polycarboxylate Liners Calcium Hydroxide Varnishes Resin In A Solvent  C L A S S I F I C AT I O N According to matrix type: Matrix Cement Phosphate Zinc Phosphate Zinc Oxide Eugenol Phenolate Calcium Hydroxide Zinc Polycarboxylate Polycarboxylate Glass Ionomer Polymethyl Methacrylate Resin Dimethyl Methacrylate Adhesive RMGI Hybrid Ionomer  C L A S S I F I C AT I O N According to mechanism: Mechanism Cement -Cement fills the restoration-tooth gap and holds by engaging in small Non-Adhesive irregularities -Example, zinc oxide, zinc phosphate -Surface irregularities are inhanced by Micromechanical air abrasion or acid etch Bonding -Improves the frictional retention -Example, resin cements -chemical bond formation between cement and tooth structure Molecular Bonding -example, zinc polycarboxylate, glass ionomer OUTLINE Ideal properties Classifications Types of cement Comparisons of luting agents Procedure techniques TYPES OF CEMENTS Zinc phosphate Zinc polycarboxylate Zinc oxide eugenol Glass ionomer Resin modified glass ionomer Resin TYPES OF CEMENTS Zinc phosphate Zinc polycarboxylate Zinc oxide eugenol Glass ionomer Resin modified glass ionomer Resin Z I N C P H O S P H AT E Reaction: Zinc oxide (powder) reacts with the phosphoric acid (liquid) ——> zinc aluminophosphate gel Exothermic reaction Z I N C P H O S P H AT E Mechanical (non-adhesive) Indication Contraindication -Cast Crowns -Ceramic Inlays -Metal Ceramic -Ceramic Veneers Crowns -Resin Bonded FDP -Cast Posts Z I N C P H O S P H AT E Advantages Disadvantages -Strength to maintain -Irritating effect on the restoration the pulp -mixed early and set -lack of anticariogenic sharply properties -lack of adhesion to the tooth Z I N C P H O S P H AT E Mixing Time 1.5 - 2 Min Working Time 5 Min Setting Time 5 - 9 Min Film Thickness 25 micrometer Z I N C P H O S P H AT E Frozen glass slab technique To prolong working time and shorten setting time Glass slab cooled at 6oC - 10oC 50-70% more powder incorporation Working time is increased by 4-11 mins Setting time shortened by 20-40% Z I N C P H O S P H AT E Modified zinc phosphate cements Copper and silver cements Higher solubility Lower strength Fluoride cements Higher solubility Stannous fluoride 1-3% TYPES OF CEMENTS Zinc phosphate Zinc polycarboxylate Zinc oxide eugenol Glass ionomer Resin modified glass ionomer Resin Z I N C P O LY C A R B O X Y L AT E Reaction: Zinc oxide (powder) reacts with the polyacrylic acid (liquid) ——> polymer chain of carbonyl groups and polyacid groups Z I N C P O LY C A R B O X Y L AT E Molecular bonding (2 MPa) Indication Contraindication -Ceramic Inlays -Cast Crowns -Ceramic Veneers -Metal Ceramic -Resin Bonded FDP Crowns -Cast Post Z I N C P O LY C A R B O X Y L AT E Advantages Disadvantages -Low irritation -Lower compressive -Chemical bond to strength tooth structure -Difficult to clean -Easy manipulation -Surface must be -Adequate strength clean for adhesion -Low solubility -Short working time -Anticariogenic Z I N C P O LY C A R B O X Y L AT E Mixing Time 30-40 Sec Working Time 2.5 Min Setting Time 6 - 9 Min Film Thickness 25 micrometer Z I N C P O LY C A R B O X Y L AT E Polyacrylic acid react with the tooth surface calcium and chelates (bonding) Zinc polycarboxylate have different flow properties than zinc phosphate, exhibiting thinning with increased shear rate Weak bond with gold and porcelain but good bond with non-precious alloys TYPES OF CEMENTS Zinc phosphate Zinc polycarboxylate Zinc oxide eugenol Glass ionomer Resin modified glass ionomer Resin ZINC OXIDE EUGENOL Reaction Zinc oxide (powder) reacts with acid eugenol (liquid) ——> Zinc eugenolate ZnO + H2O ———> Zn(OH)2 Zn(OH)2 + 2HE ———> ZnE2n + 2H2O ZINC OXIDE EUGENOL Mechanical (non-adhesive) Indication Contraindication If resin cements are to Used as a temporary be used with the final cement agent cementation ZINC OXIDE EUGENOL Advantages Disadvantages -Sedative effect on -Low strength pulpal tissue -Disintegration in oral -Good sealing ability fluids -Resistance to -Less anticariogeNic marginal penetration -Highest solubility Good thermal insulation ZINC OXIDE EUGENOL Mixing Time Until Homogeneous Affected By Temp. & Working Time Moisture Setting Time 4 - 10 Min Film Thickness 25 micrometer ZINC OXIDE EUGENOL Classification according to ADA specification no. 30 Type I: temporary cement Type II: definitive cement Type III: temporary restoration and thermal insulating base Type IV: cavity liner ZINC OXIDE EUGENOL Powder : Liquid: 4:1, 6:1 (by weight) Two paste: same amount Affected by moisture and temp. Sets faster in oral cavity Reversible reaction TYPES OF CEMENTS Zinc phosphate Zinc polycarboxylate Zinc oxide eugenol Glass ionomer Resin modified glass ionomer Resin GLASS IONOMER Reaction Silicate glass (powder) reacts with polyacrylic acid (liquid) ——> glass ionomer GLASS IONOMER Molecular bonding (3-5 MPa) Indication Contraindication -Cast Crowns -Metal Ceramic -Ceramic Restorations Crowns -Resin Bonded FDP -Cast Post GLASS IONOMER Advantages Disadvantages -Bonding Property -Low Flexural -Anticariogenic Effect Strength -Easy To Use -High Modulus Of (Capsule) Elasticity -Different Shades -Absorbs Water -Biocompatible During Setting Phase -Good Marginal Seal -Less Esthetic GLASS IONOMER Mixing Time Depend On Type Working Time 3 - 5 Min Setting Time 5 - 9 Min Film Thickness 25 micrometer GLASS IONOMER Powder : liquid (follow instruction) Capsule type (like amalgam) Two paste system (mix homogeneous) GLASS IONOMER Sensitive to water and air When exposed to ambient air it will craze and crack ——> cohesive failure from micro crack formation Smith D.C. The cause of post cement sensitivity —> bacterial invasion, hydraulic pressure and acidity in the early setting stage and wash of thin mix. TYPES OF CEMENTS Zinc phosphate Zinc polycarboxylate Zinc oxide eugenol Glass ionomer Resin modified glass ionomer Resin RESIN MODIFIED GLASS IONOMER Reaction Radio-opaque fluroaluminosilicate glass and micro encapsulated potassium sulfate (powder) reacts with polycarboxylate acid modified with methacrylate groups, 2 HEMA and tartaric acid (liquid) ——> acid/base glass ionomer reaction with a self cured or light cured polymerization of the methacrylate group RESIN MODIFIED GLASS IONOMER Molecular bonding >10 MPa Indication Contraindication -Cast Crowns -Metal Ceramic Crowns -Ceramic Restorations -Cast Post -Resin Bonded FDP -The Material Of Choice For Casted Restorations RESIN MODIFIED GLASS IONOMER Advantages Disadvantages -Set On Demand -Lower Flexural -Immediate Finishing Strength -Better Esthetics -High Modulus Of -Higher Tensile Elasticity Strength -Absorbs Water -Anticariogenic During Setting Phase Bond To Resin But Less Than GI Composite -Less Esthetic RESIN MODIFIED GLASS IONOMER Mixing Time 8 - 10 Sec Working Time 2.5 Min Setting Time 5 - 9 Min Film Thickness 25 micrometer RESIN MODIFIED GLASS IONOMER Chemical bond The moisture sensitivity remains an issue The polyalkenoic acid plays a role starting the adhesion “diffusion based adhesion” Difficulty of removal after set TYPES OF CEMENTS Zinc phosphate Zinc polycarboxylate Zinc oxide eugenol Glass ionomer Resin modified glass ionomer Resin RESIN Reaction Polymerization reaction, combination of dimethacrylate with other monomers containing various amounts of ceramic fillers RESIN Micromechanical bonding 18-20nMPa Indication Contraindication -Light Cured Cements -All Ceramic Are Contraindicated Restorations With Metal Or Thick Zirconia Restorations RESIN Advantages Disadvantages -Excellent Mechanical -Polymerization Properties Shrinkage -High Bond Strength -Microleakage -High Esthetics -Technique Sensitive -Cleaning After Cementation Takes Time RESIN Mixing Time Depends On Type Working Time Depends On Type Setting Time 3 - 7 Min Film Thickness 20 - 60 micrometer RESIN Classification according to mechanism of matrix formation Light cured Self cured Dual cured RESIN Classification based on bonding procedure Total etch (etch + bond + resin) One step (etch & bond + resin) Self adhesive (etch + bond & resin) Self etch, self adhesive (etch, bond & resin) OUTLINE Ideal properties Classifications Types of cement Comparisons of luting agents Procedure techniques OUTLINE Ideal properties Classifications Types of cement Comparisons of luting agents Procedure techniques POWDER : LIQUID RESIN FDP C E M E N TAT I O N