Polyvinyl siloxane (PVS), also called poly-vinyl siloxane, vinyl polysiloxane (VPS), or vinylpolysiloxane, is an addition-reaction
silicone elastomer (an addition silicone). It is a viscous liquid that cures (solidifies) quickly into a rubber-like solid, taking the shape of whatever surface it was lying against while curing. As with two-part
epoxy
Epoxy is the family of basic components or Curing (chemistry), cured end products of epoxy resins. Epoxy resins, also known as polyepoxides, are a class of reactive prepolymers and polymers which contain epoxide groups. The epoxide functional ...
, its package keeps its two component liquids in separate tubes until the moment they are mixed and applied, because once mixed, they cure (harden) rapidly. Polyvinyl siloxane is widely used in
dentistry
Dentistry, also known as dental medicine and oral medicine, is the branch of medicine focused on the teeth, gums, and mouth. It consists of the study, diagnosis, prevention, management, and treatment of diseases, disorders, and conditions ...
as an
impression
An impression is the overall effect of something.
Impression or impressions may also refer to:
Biology
* Colic impression, a feature of the gall bladder
* Duodenal impression, medial to the renal impression
* Gastric impression, a feature of th ...
material. It is also used in other contexts where an impression similar to a dental impression is needed, such as in
audiology
Audiology (from Latin , "to hear"; and from Greek , '' -logia'') is a branch of science that studies hearing, balance, and related disorders. Audiologists treat those with hearing loss and proactively prevent related damage. By employing vario ...
(to take ear impressions for fitting custom hearing protection or hearing aids
) or in industrial applications (such as to aid in the inspection of interior features of machined parts, for example, internal grooves inside
bores). Polyvinyl siloxane was commercially introduced in the 1970s.
To create the material, the user simply mixes a colored putty (often blue or pink) with a white putty, and the chemical reaction begins. PVS with a wide variety of working and setting times is available commercially.
Final set is noted when the product rebounds upon touching with a blunt or sharp instrument.
This reaction also gives off
hydrogen gas
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, a ...
and it is therefore advisable to wait up to an hour before pouring the ensuing cast.
In dentistry, this material is commonly referred to as having light or heavy body depending on specific usage.
See also
*
Dental impression
*
Dentures
Dentures (also known as false teeth) are prosthetic devices constructed to replace missing teeth, and are supported by the surrounding soft and hard tissues of the oral cavity. Conventional dentures are removable ( removable partial denture ...
References
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Dental materials
Polymers
Impression material