Dental materials

Dental materials is an important subject for dental students. It mainly deals with the materials used in both practical and laboratory dentistry. It gives an insight about the physical chemical and the mechanical properties of the materials that are used in dentistry. The dental materials may be broadly classified on the basis of their use. They are:
 * 1) impression materials,
 * 2) casting materials,
 * 3) restorative materials,
 * 4) orthodontic bands and wires,
 * 5) cements, bases, varnishes and liners, and
 * 6) waxes.

The components of each class range from polymers to metals. There are many materials under each type of material. The adequate material can be chosen according to the requisites.

Impression materials
An impression is a negative recording of the oral cavity and associated structure in appropriate and accurate dimensions. The material that helps in taking an impression is called impression material. The most common impression material is alginate. Alginate is an irreversible hydrocolloid. Meaning that it cannot return to the sol state after it turns into a gel. The biggest ingredient in alginate is potassium alginate which is found in seaweed. It is also used for a thickening agent in some ice creams.