Dental cement
Encyclopedia
Dental cements are hard, brittle materials formed by mixing powder and liquid together. They are either resin cements or acid-base cements. In the latter the powder is a basic metal oxide or silicate and the liquid is acidic. An acid base reaction occurs with the formation of a metal salt which acts as the cementing matrix. Dental cements are used for a variety of dental and orthodontic applications, including use as luting agent
s, pulp
-protecting agents or cavity
-lining material. Furthermore, they are used to form an insulating layer under metallic or ceramic restorations
, and protect the pulp from injury. This helps in sealing or fixing and casting inlays, onlays or any such substance to both dentin
and enamel
.
Cements can be classified based on the type of their matrix:
Translucency.
Luting agent
In dentistry, a luting agent is a viscous material placed between tooth structure and a prosthesis, that hardens through chemical reactions to firmly attach the prosthesis to the tooth structure.-Cements as luting agents:...
s, pulp
Pulp (tooth)
The dental pulp is the part in the center of a tooth made up of living connective tissue and cells called odontoblasts.- Anatomy :Each person can have a total of up to 52 pulp organs, 32 in the permanent and 20 in the primary teeth....
-protecting agents or cavity
Dental caries
Dental caries, also known as tooth decay or a cavity, is an irreversible infection usually bacterial in origin that causes demineralization of the hard tissues and destruction of the organic matter of the tooth, usually by production of acid by hydrolysis of the food debris accumulated on the...
-lining material. Furthermore, they are used to form an insulating layer under metallic or ceramic restorations
Dental restoration
A dental restoration or dental filling is a dental restorative material used to restore the function, integrity and morphology of missing tooth structure. The structural loss typically results from caries or external trauma. It is also lost intentionally during tooth preparation to improve the...
, and protect the pulp from injury. This helps in sealing or fixing and casting inlays, onlays or any such substance to both dentin
Dentin
Dentine is a calcified tissue of the body, and along with enamel, cementum, and pulp is one of the four major components of teeth. Usually, it is covered by enamel on the crown and cementum on the root and surrounds the entire pulp...
and enamel
Tooth enamel
Tooth enamel, along with dentin, cementum, and dental pulp is one of the four major tissues that make up the tooth in vertebrates. It is the hardest and most highly mineralized substance in the human body. Tooth enamel is also found in the dermal denticles of sharks...
.
Composition and classification
Cements are classified on the basis of their components. Generally, they can be classified into categories:- Water-based acid-base cements: zinc phosphateZinc phosphateZinc phosphate is an inorganic chemical compound used as a corrosion resistant coating on metal surfaces either as part of an electroplating process or applied as a primer pigment . Zinc phosphate coats better on a crystalline structure than bare metal, so a seeding agent is often used as a...
(Zn3(PO4)2), Zinc Polyacrylate(Polycarboxylate), glass ionomer (GIC)Glass ionomer cementA Glass Ionomer Cement is a dental restorative material used in dentistry for filling teeth and luting cements. These materials are based on the reaction of silicate glass powder and polyalkenoic acid...
. These contain metal oxide or silicate fillers embedded in a salt matrix. - Non-aqueous acid-base cements: Zinc oxide eugenolZinc Oxide EugenolZinc oxide eugenol is a material created by the combination of zinc oxide and eugenol contained in oil of cloves. An acid-base reaction takes place with the formation of zinc eugenolate chelate. The reaction is catalysed by water and is accelerated by the presence metal salts. ZOE can be used as...
and Non-eugenol zinc oxideZinc oxideZinc oxide is an inorganic compound with the formula ZnO. It is a white powder that is insoluble in water. The powder is widely used as an additive into numerous materials and products including plastics, ceramics, glass, cement, rubber , lubricants, paints, ointments, adhesives, sealants,...
. These contain metal oxide fillers embedded in a metal salt matrix. - Resin-based: AcrylateAcrylateThe acrylate ion is the ion of acrylic acid.Acrylates are the salts and esters of acrylic acid. They are also known as propenoates ....
or methacrylateMethacrylateMethacrylates are the salts or esters of methacrylic acid.Methacrylates contain methyl-vinyl groups, that is, two carbon atoms double bonded to each other, directly attached to the carbonyl carbon, and wherein the vinyl group is substituted with a non-terminal methyl group.Methacrylates are common...
resin cements, including the latest generation of self-adhesive resin cements which contain silicateSilicateA silicate is a compound containing a silicon bearing anion. The great majority of silicates are oxides, but hexafluorosilicate and other anions are also included. This article focuses mainly on the Si-O anions. Silicates comprise the majority of the earth's crust, as well as the other...
or other types of fillers in an organic resin matrix.
Cements can be classified based on the type of their matrix:
- PhosphatePhosphateA phosphate, an inorganic chemical, is a salt of phosphoric acid. In organic chemistry, a phosphate, or organophosphate, is an ester of phosphoric acid. Organic phosphates are important in biochemistry and biogeochemistry or ecology. Inorganic phosphates are mined to obtain phosphorus for use in...
(zinc phosphateZinc phosphateZinc phosphate is an inorganic chemical compound used as a corrosion resistant coating on metal surfaces either as part of an electroplating process or applied as a primer pigment . Zinc phosphate coats better on a crystalline structure than bare metal, so a seeding agent is often used as a...
, silico phosphate) - Polycarboxylate (zinc polycarboxylate, glass ionomer)
- Phenolate (Zinc oxide–eugenol and EBA)
- ResinResinResin in the most specific use of the term is a hydrocarbon secretion of many plants, particularly coniferous trees. Resins are valued for their chemical properties and associated uses, such as the production of varnishes, adhesives, and food glazing agents; as an important source of raw materials...
(polymeric)
Requirements
The requirements for dental cements are that they should:- Be non irritant to pulpPulp (tooth)The dental pulp is the part in the center of a tooth made up of living connective tissue and cells called odontoblasts.- Anatomy :Each person can have a total of up to 52 pulp organs, 32 in the permanent and 20 in the primary teeth....
and gingivaGingivaThe gingiva , or gums, consists of the mucosal tissue that lies over the mandible and maxilla inside the mouth.-General description:...
(gums) and should not support the growth of secondary cariesDental cariesDental caries, also known as tooth decay or a cavity, is an irreversible infection usually bacterial in origin that causes demineralization of the hard tissues and destruction of the organic matter of the tooth, usually by production of acid by hydrolysis of the food debris accumulated on the...
. (This last property is called cariostatic or anticariogenicity). - Form a strong bond with enamelTooth enamelTooth enamel, along with dentin, cementum, and dental pulp is one of the four major tissues that make up the tooth in vertebrates. It is the hardest and most highly mineralized substance in the human body. Tooth enamel is also found in the dermal denticles of sharks...
and dentinDentinDentine is a calcified tissue of the body, and along with enamel, cementum, and pulp is one of the four major components of teeth. Usually, it is covered by enamel on the crown and cementum on the root and surrounds the entire pulp...
. - Provide good marginal sealing to prevent marginal leakage.
- Be resistant to dissolution in salivaSalivaSaliva , referred to in various contexts as spit, spittle, drivel, drool, or slobber, is the watery substance produced in the mouths of humans and most other animals. Saliva is a component of oral fluid. In mammals, saliva is produced in and secreted from the three pairs of major salivary glands,...
, or in any oral fluid. - Have good aesthetics and good thermal and chemical resistance. (Opacity to X-rays is also preferred for diagnostic purposes).
Translucency.