are partially crosslinked ionomeric resins, and perform in peelable seal applications through delamination of the seal/seal interface.
are polymers that contain a small number of ionic salt groups attached to hydrophobic organic backbone chains.
Seppa, "Studies on the effect of fluoride release by glass ionomers
in the oral cavity," Advances in Dental Research, vol.
Mount, "Glass ionomers
: a review of their current status," Operative dentistry, vol.
This explains why glass ionomers
, markedly less mechanically resistant than composites, may have a role in paedodontics.
Early and long-term wear of conventional and resin-modifed glass ionomers
. J Dent Res, 1996; 75:1613-1619.
In fact, polymers containing ionic functionality in 15 mol% or less of the polymer repeat units have been defined as a unique class of polymers called ionomers
. (8) The unique properties of ionomers
which result from the aggregation of ionic groups into nanometer scale domains, typically referred to as multiplets, has resulted in the application of these materials in areas such as engineering thermoplastics, thermoplastic elastomers, packaging materials, and adhesives.
, used in making the encapsulatnt sheets, are thermoplastic polymers.
* Total Petrochemicals in Houston has invented what it calls a "breakthrough resin technology," believed to be the first commercial styrenic ionomer
. Previous commercial thermoplastic ionomers
have all been based on ethylene, though styrene-based ionomers
are known in academic literature.
Sealants are generally either resin-based or glass ionomers
. Resin-based sealants, with their characteristics of flow ability and retentiveness, work exceptionally well and serve their function for many years when placed properly.
were introduced to the profession 25 years ago and have been shown to be a very useful adjunct to restorative dentistry.