Comparison of Physical Properties of Tooth Colored Restorative Materials

Tooth colored Restorative Dental Materials are being used more profusely in Dentistry as the need for Aesthetics has increased and the tooth colored materials are having similar properties to materials like Amalgam. Here i am going to compare the various physical properties of Tooth colored Restorative Dental Materials:

1. Strength
2. Compressive Strength
3. Modulus of Elasticity
4. Shrinkage during Setting
5. Co-efficient of Thermal Expansion
6. Abrasive Resistance
7. Solubility
8. Syneresis
9. Plasticity
10. Microleakage
11. Anticariogenecity
12. Rate of Hardening
13. Refractive Index of materials

 Strength Properties:

• Composite Resins: Highest Tensile and Compressive Strength (compared to all tooth colored Restorative materials)
• Filled Resins: Lowest Compressive Strength
• Silicate and alumino-silicate polyacrylate (ASPA): Lowest Tensile Strength

Compressive Strength Comparison:

• Enamel: 40,000 to 56,000 psi
• Dentin: 30,000 to 50,000 psi
• Composite: 55,000 psi
• Silicate: 24,000 to 31,000 psi
• Alumino-silicate polyacrylate (ASPA): 23,000 to 28000 psi

Modulus of Elasticity:

• Highest in Silicate Cements and Composite Cements

Shrinkage during Setting:

• Unfilled Resin has maximum Shrinkage – 7 %
• Silicate Cements have Minimum Shrinkage – 0.2 to 0.5 %

Co-efficient of Thermal Expansion:

• Silicate Cement: Closest to Natural Tooth
• Composite: Closest to Amalgam (25 to 35 ppm/degree centigrade)

Abrasive Resistance:

• Hybrid Composite: Most Abrasive resistant
• Microfilled Composite: Least Abrasive resistant

Solubility:

• Silicate Cements: Most Soluble in Water, Plaque, Acids like acetic Acid, citric Acid
• ASPA or GIC: Less soluble than Silicates
• Composite: Soluble in Organic Solvents which may be introduced Intra Orally Ex: Ethanol

Syneresis:

• Silicate Cements: Maximum
• ASPA or GIC: Less than Silicate Cements

Plasticity:

• Composites, Unfilled Resins

Microleakage:

• Unfilled Resins and Second Generation Composites: Maximum

Anticariogenicity:

• Silicate Cement: 700 ppm
• ASPA: 2200 ppm

Refractive Index:

• Refractive Index of Enamel: 1.6 degrees
• Refractive Index of Dentin: 1.55 degrees
• Silicate Cements are Closest to Enamel and Dentin: 1.4 to 1.6 degrees

Rate of Hardening:

• Resin Cements: 15 mins
• Silicate Cements: 48 mins