Properties, classifications, and comparisons
Addition silicone (PVS) = most accurate, no byproduct. Condensation silicone = releases alcohol. Polysulfide = messiest, longest setting. Polyether = stiffest, hydrophilic. Alginate = snap set, no reuse.
ZPC = gold standard for luting (strongest compressive). GIC = fluoride release + chemical bond. Resin cement = best with all-ceramic. ZOE = most biocompatible, least strength.
Type I gold = inlays (soft). Type IV = partial denture frameworks (extra hard). Ni-Cr = most common base metal alloy. Gypsum bonded investment = gold casting. Phosphate bonded = base metal.
Feldspathic = most esthetic, weakest. Leucite-reinforced = IPS Empress. Lithium disilicate = IPS e.max (most popular). Zirconia = strongest ceramic, opaque. CAD-CAM = digital fabrication.
Stress = Force/Area. Strain = ΔL/L. Elastic modulus = stress/strain. Toughness = area under curve. Resilience = energy absorbed in elastic region. Hardness tests: Knoop (micro), Vickers, Brinell (macro).
PMMA = heat cure acrylic = denture base. Porosity in acrylic: Gaseous (most common) > Contraction > Granular. Wax pattern → Investment → Burnout → Casting = Lost wax technique.