Learning objectives
Provide students with the basic concepts on the rational use of dental biomaterials. In particular, student must possess an operative and detailed knowledge of the physical and chemical laws that are at the basis of the use of biomaterials. They must also know the principles of practical clinical use of materials in the different branches of dentistry.
Course unit content
GENERAL CONCEPTS OF PHYSICS AND METALLURGY
Elasticity and Hooke's law. Biofunctionality and biocompatibility. Solid body; crystal structure; elementary cells, lattices. point defects, linear, extended. Metals and alloys: phase diagrams, noble alloys, alloys for removable dentures, for metal-ceramics. Steel. Titanium. Ni-Ti alloys. Properties of alloys: elastic deformation, resilience, hardness, chemical and electrochemical corrosion in the oral cavity.
IMPRESSION MATERIALS
Elastic and non-elastic materials. Composition and properties of plaster, wax, zinc oxide and eugenol paste. Reversible and irreversible hydrocolloids. Sodium alginate: composition, setting reaction and properties. Agar and its properties. Properties of impression materials: dimensional variation, reproducibility of detail, hardness, wettability, adhesion, tear strength, viscosity, viscoelasticity, elastic recovery, permanent deformation.
CEMENT.
Phosphoric acid cements, calcium hydroxide cements, silicate cements, EBA cements, trioxide cements.
GLASS IONOMERS
Glass ionomers and resin-modified glass ionomers. Mechanisms of polymerization and hardening. Reinforcing cariostatic additives. Microstructure and nanostructure. Proton attack and fluoride release. Dimensional variation, hardness, porosity, swelling in the mouth.
POLYMERS IN DENTISTRY
Structure and general properties of polymers. Properties of macromolecules: length, weight, and average size. Macromolecules in solution and in the condensed state. Amorphous and crystalline polymers. Stages of the polymerization. Polycondensation: polysulfides, silicones by condensation, composition and reaction. Polyaddition: mechanisms of polyaddition, polyvinyl siloxanes; polyethers, composition and reaction.
THERMOPLASTIC AND THERMOSETTING RESINS
Polymethylmethacrylate resins. Polymerization mechanisms: thermopolymerization, self-curing, microwave polymerization. Hardening reaction properties. Resins for denture rebasing.
COMPOSITES
Bis-GMA-based composites. Fillers. Micro-filled composites, hybrid composites. Curing mechanisms, self-activation; photoactivation. The activator-initiator system. Polymerization by irradiation. The camphorquinone-tertiary amine system. Degree of polymer conversion. Additive and subtractive combination.
GRAFTING BIOMATERIALS
Biocompatibility. The composition and function of the Extracellular Matrix. Bone physiology. Protein adsorption on biomaterials. Bone grafting materials. Bioceramics. Polymers. Metals. Titanium. Tissue engineering and scaffold. Hydrogels. Material functionalization.
Bibliography
G. SPOTO e A.A. VARI.: M. MATERIALI E TECNOLOGIE ODONTOSTOMATOLOGICHE. ED. ARIESDUE 2019 (THIRD EDITION)
Teaching methods
Lectures supplemented by discussion, to train students’ critical skills and to provide them with a knowledge of dental materials that can be useful in diagnosing and treat dental pathologies and thus assist to solve specific problems of professional dentists.
Assessment methods and criteria
Oral examination to ensure the quality and level of knowledge and understanding of the course content and the ability to apply the acquired knowledge to professional practice. The examination will also evaluate the quality of students’ participation in class.
