Section I. INTRODUCTION TO DENTAL MATERIALS
Dental materials used in the dental profession are indeed many, varied, and
complex. The dental specialist who prepares and uses many of these materials in
assisting the dental officer must know their composition, properties, uses, and
manipulation. Restorative materials, miscellaneous dental materials, dental waxes,
gypsum products, and impression materials are covered in this subcourse. A thorough
knowledge of dental materials and the skill to manipulate these materials is one of the
important duties of a dental specialist.
RESTORATIVE MATERIALS - GENERAL
Restorative materials are the metallic or nonmetallic materials used to restore
diseased or damaged teeth to health and function. Restorative materials have been
greatly improved, although a universally ideal, restorative material has not yet been
developed. The corrosive nature of saliva and the expansion and contraction of tooth
structure with changes in temperature make great demands upon a restorative material.
The stress brought to bear on the restoration by masticatory forces also makes great
demands. Restorative materials must be compatible with living tissue. If used in the
anterior region of the mouth, the materials must also be esthetically pleasing.
Restorative materials, used when and where indicated, help to ensure the placement of
a successful restoration and preservation of the tooth.
PHYSICAL PROPERTIES OF MATERIALS
Definite and precise terms are used to describe the physical properties of dental
materials. These terms must be clearly defined in order for one to understand the
interrelationships between physical properties, structures, and composition. The
following definitions apply to metals or alloys used in the Army Dental Service.
indentation or scratching. It is an indication of the strength and wear ability of an alloy
b. Ductility. Ductility is the measure of the capacity of a metal to be stretched
or drawn by a pulling or tensile force without fracturing. This property permits a metal to
be drawn into a thin wire.
c. Malleability. Malleability is the measure of the capacity of a metal to be
extended in all directions by a compressive force, such as rolling or hammering. This
property permits a metal to be shaped into a thin sheet or plate.