What are the classification of impression materials?

Classification of Impression Materials

By their composition, the impression materials are divided into three major groups: nonaqueous elastomers, hydrocolloids, and inelastic materials. Elastomers include polysulfide, condensation and addition silicone, and polyether. Hydrocolloids are alginate and agar.

What are the three classifications of impressions used in dentistry?

There are three main types of dental impressions — preliminary, final, and bite registration.

What are dental impression materials?

Impression materials are used in dentistry to record the details of intraoral structures to fabricate a reproduction of teeth and soft tissues for the construction of dental prostheses.

What is impression tray classification?

Plastic impression trays are generally single use (disposable). Another special type of plastic impression tray is the “dual-arch” tray. Dual-arch trays consist of a handle, an external structure (vestibular and lingual) in rigid plastic in the shape of a “U” and a floor made from flexible plastic mesh.

What are the 3 types of impressions?

Impressions fall into three basic categories: patent, latent, and plastic. Plastic impressions are three-dimensional imprints. These impressions can be left in soft materials such as snow, mud, soil, or soap. Depending on how it is made, impression evidence may be either class evidence or trace evidence.

What types of impressions are there?

Types of Impression Material
  • Light body-is the easiest-flowing material to flow.
  • Regular body-is slightly thicker than the light body form.
  • Heavy body –is the thickest of the three forms.

What are the two basic types of impression trays?

There are two kinds of full and partial denture trays: trays with perforations, for use with alginate impression materials, and solid, nonperforated trays for use with solid impression materials, such as red compound or fast-set impression plaster No.

What is alginate impression material?

Alginate is an elastic, irreversible hydrocolloid impression material. Irreversible hydrocolloid impressions form an inseparable part of indirect restorations. Alginate is one of the most frequently used dental materials; and alginate impression is a simple, cost-effective, and indispensable part of dental practice.

What are the three types of custom impression trays?

Impression trays are supplied as quadrant trays, which cover half of the arch; section trays, which are suited for the anterior teeth; and full arch trays, which cover the complete arch.

How are impressions used in dentistry?

Impression materials are used to copy the teeth and surrounding oral structures by creating a dental impression poured with dental plaster to fabricate a dental cast. This procedure provides a tridimensional and accurate mouth replica, allowing dental work even in the absence of the patient.

What are the three curing stages of impression materials?

Curing Stages of Elastomeric Materials
  • Initial set.
  • Final set.
  • Final cure.

What is impression in dentistry?

Dental impressions are an impression of the teeth and the mouth to form shapes from which objects are formed. Dental impressions are used to create a close replica of either your set of teeth or your oral tissue or both.

What are the four types of elastomeric materials?

There are 4 groups of elastomers; polysulfide, condensation silicone, addition silicone and polyether; each differ in their setting mechanism and their physical and chemical properties.

What material is used for final impressions?

There are many materials for the final impression, such as gypsum, zinc oxide and eugenol (ZOE) paste, polysulfide rubber, polyether, polyvinyl siloxane, and alginate.

What is PVS in dental?

[1] The most popular elastomer used in the dental practice today is the polyvinyl siloxane (PVS). PVS impression materials have low dimensional change, low creep, and relatively short setting time, have moderate to high tear resistance.

What is the difference between hydrocolloid and elastomeric materials?

HYDROCOLLOIDS: Substances that exist in sol/gel state. It can be converted from sol to gel and the opposite through physical or chemical reactions. The reaction could be reversible or irreversible. ELASTOMERS: Rubber-like polymers that show an elastic behavior at the time of load application.

What is putty impression material?

Silicone impression material consists of a base and catalyst in a putty consistency. Silicone impressions are classified according to their method of polymerisation on setting. They are available in a range of viscosities including light, medium, heavy and very high viscosity (or putty) material.