Esthetic Dental Materials

1. Esthetic Dental Materials Joseph W. Parkinson, DDS

2. Esthetic Dental Materials • Single -Component Systems-Homogeneous material • Feldspathic Porcelain • Reinforced glass ceramics • Pressed Ceramics • Structural Limitations • Need support from tooth structure • Restricts to veneers, inlays, onlays

3. Esthetic Dental Materials • Single-Component Systems (con’t) • CAD/CAM (CEREC) • Esthetic restorations • Good marginal fit • Brittle • Need adequate tooth structure • Meticulous bonding • Single appt- good for patients, practitioners • High initial investment- affect treatment decisions? Are you treatment planning because of the cost of the machine or because the patient needs that particular service. Must be careful with these investments.

4. Esthetic Dental Materials • iTERO • Similar to CAD/CAM • Prep design critical Digital scan of prep email to lab, CAD CAM and Cerec have uncoupled their scan from the milling machine, can do the same thing with CAD CAM now. Learning curve with CAD/CAM on restoration increased remakes initially, now using more iTERO prep design is critical – good scan of margins very important.

5. Two-Component Ceramic Systems • Pressed Ceramic Restorations • Exceptional Esthetics • Very good marginal fit • Leucite-reinforced pressed ceramics (IPS Empress, Finesse) • Flexural strength of 140-180MPa, Feldspathic Porcelain 80 MPa • Should be restricted to single units in anterior, partial coverage restorations in posterior

7. Two Component Ceramic Systems • Pressed Ceramic Restorations-con’t. • Lithium Disilicate-Reinforced Pressed Ceramics (IPS Empress 2, Eris. e. Max Press) • Flexural Strenghth 300 MPa • Short span bridges anterior to second premolar

8. Two Component Ceramic Systems • Adhesively bonded resin cements required for cementing pressed ceramics • Maintain their translucency • Shade of cement can affect final shade • Glass component in pressed ceramics susceptible to etching with HF acid • Etching and silanization form bond with cement, tooth, restoration • Leucite and Lithium Disilicate in pressed ceramics can be used with CAD/CAM

9. Two Component Ceramic Systems • Glass- Infiltrated Ceramics • Zirconia, Alumina, Spinel • Flexural Strength-350MPa for Spinel, 500MPa for Alumina, 700 MPa for Zirconia • Prep similar to pressed ceramics • Even circumferential reduction • Deep chamfer reduction recommended • Moderate taper, no sharp line angles Glass is infiltrated into a crystalline structure.

10. Two Component Ceramic Systems • Glass- Infiltrated Ceramics- con’t. • Frameworks for full coverage crowns in Anterior • Short span bridges replacing premolars or anterior teeth • Conventional Cementation Techniques (GI or Zn Phosphate) *most use GI

11. Two Component Ceramic Systems • Fully Sintered Ceramics • Based on pure crystalline ceramic copings • Stronger than pressed or glass-infused ceramic- e.g. Procera All-Ceram, Procera All-Zircon, Lava • Lava-Flexural Strength of 1,100 MPa- can be as thin as 0.3mm Fully Sintered Ceramics = polycrystalline structure Veneered to porcelain copings can be as thin as 0.3 mm

12. Two Component Ceramic Systems • Pressed to Zirconium • Feldspathic Porcelain veneered over fully sintered zirconium • Chipping of porcelain similar to metal ceramic PFZ is most popular, high success rate

13. Selecting The Right One • Meeting the patient’s restorative needs -#1 • Look at patient’s smile line • If gingival margin exposed during smiling, then metal should not show • Opaque copings of alumina or zirconia may look unnatural if extended to facial margin • Glass ceramic facial margin(pressed or stacked) is only option for patient with high smile line • Can use metal ceramic w/all porcelain margin or pressed all ceramic or pressed to Zn

15. Selecting The Right One • Shade matching- #2 • All systems can block out unwanted background color either intrinsically or with opaque modifiers • Matching existing teeth or recreating imperfect natural is a greater challenge-pressed ceramic the best • Posterior teeth-structural implications • Multiple cusps-splitting forces\ • Pressed ceramics-bad • Crystalline ceramics-glass infiltrated or fully sintered –better • Primary drawback to Zn is cost

17. Selecting The Right One • Bridges • Need for strength greater • Lithium Disilicate-based pressed ceramics can be used for short spans in anterior and premolar-not molar abutments or pontics • Glass infiltrated ceramic frameworks-similar indications-less natural appearance • Zirconia frameworks-first choice for long span posterior bridges

18. In The Future • Zirconia-material of present and near future • Maryland bridges, inlay/onlay retained bridges • Abutments for implant retained restorations IntraOral Scanning devices-CAD/CAM, iTero

20. In The Future • Overlooked Problem-Replacement • More likely to result in fractured or grossly over-reduced tooth than metal ceramic due to visual similarity and tenacious grip on tooth structure Bond to teeth really well difficult to remove, and look like tooth too much stacked porcelain = unstable need to modify and monitor prep design.

21. Dental Cements • Zinc Phosphate • Advantages • Easy to mix • Well-defined setting time • Working time that can be prolonged by adjusting mixing technique • Low cost

22. Disadvantages • Potential for pulpal irritation due to low pH (2) • No antibacterial function • Brittle • No adhesive qualities • More soluble than most cements • Opaque • Exothermic reaction

23. Polycarboxylate Cement • Advantages • They bond to enamel and dentin with a similar mechanism found in glass-ionomer cements • Low pulpal irritation • Strength, solubility, and film thickness comparable to zinc phosphate • Antibacterial action long term temporaries

24. Disadvantages • Properties highly dependent on mixing procedure • Short working time • Longer setting time • Clean up difficult if excess is allowed to harden

25. Glass ionomers • Advantages • Fluoride release • Cariostatic potential • Similar coefficient of thermal expansion when compared to hard tissue • Chemical adhesion to dentin and enamel • Capsules for consistent powder-to-liquid ratio • Lower opacity than zinc phosphate

26. Disadvantages • Lower than resin cements in fracture toughness, brittleness, higher solubility and wear • Absorb moisture during initial setting phase

27. Resin Modified Glass Ionomers • Advantages • Less sensitivity to moisture during initial setting phase • Capable of bonding to composites • Some fluoride release RelyX

28. Disadvantages • Hydrophilic behavior • Water absorption and hygroscopic expansion—not recommended for all ceramic crowns or veneers • More leakage than resin-based materials

29. Resin-based Cements • Advantages • High compressive and tensile strength • Good biocompatibility • Intra-oral solubility is lowest • Good adhesion • Reach maximum strength in a short time

30. Disadvantages • Higher film thickness than RMGI or GI • Much more difficult to remove excess once cured • When used with acid-etching techniques, can cause post-operative sensitivity

31. The Use of Luting Materials Classified by Type of Restoration 1. Low-Strength Ceramic Restorations A. Veneers (IPS Empress) Recommended Material: Light or Dual-Cured Cement (Variolink II, Calibra) B. Inlay, Onlay, Full Crown (IPS Empress, VITA PM) Recommended Material: Dual or Self-Cure Cement (Variolink II, Panavia 21)

32. 2. High-Strength Ceramic Restorations (Lava, ProCeraZirconia) A. Core Reinforced Full Ceramic Crowns, FPDs, Posts and Cores Recommended Material: Conventional Cement (Zinc Phosphate or GI) or a dual or self-cured resin cement for adhesive cementation (RelyXUnicemMaxcem, Multilink Sprint, Panavia F 2.0)

33. References • Esthetic Dentistry in Clinical Practice • Mark Geissberger/1sted, 2010, Blackwell Publishing • Bay View Dental lab