Mechanical properties of dental restorative materials

Thesis (D.Sc.D.)--Boston University, Henry M. Goldman School of Dental Medicine, 2006 (Dept. of Restorative Sciences and Biomaterials).Includes bibliographical references: leaves 358-373.In our experiment we tested the mechanical properties for veneering restorative dental materials. 15 conventional veneering materials, which are prepared using powder-slurry technique, and used to veneer metal-, alumina-, Zirconia-, and lithium disilicate-substrates. Also 2 machinable ceramic materials (Mark II and TriLuxe) and one machinable composite material (MZ100 Paradigm) are also tested. Type III gold and Acrylic resin was used in some tests as control when applicable. Objectives: to test the previously mentioned restorative materials in wear against enamel and toothbrushing, flexural strength, hardness, fracture toughness, crack length on polishing surfaces and after wear, surface roughness on polishing surfaces and after wear, and to look at the microstructure of these materials. Methods: Bars for flexural strength (12x2x2.8[plus or minus]0.02 mm) and square samples (9x9x2[plus or minus]1mm) for the rest of the tests were fabricated from each material. Instron machine used for flexural strength, Pin-On-Plate wear machine used for wear, and Micromat 2003 microhardness indenter used for hardness, crack length and subsequently fracture toughness calculation. Results and statistical analysis: Mark II and TriLuxe both performed better than the conventional materials in all tests, while Vitadur Alpha (the old conventional veneering material) performed statistically lower than all the other materials tested in most of the experiments performed. Discussion: Controlled manufacturing produced better materials that performed better than conventional materials in most tests, while improvement in the microstructure produced better materials with improved mechanical properties