Dental Cements

Adhesion in Dentistry
-used every time trying to get something to stick to tooth (even sealant/crown)
-Sealant: micromechanical (creating multiple interlocking structures when etching) sealants/composite/brackets
-Crowns/bridges: macromechanical (gluing)

Overview (cements)
-permanent (luting)/cementation: crowns/bridges/veneers
-semi-permanent: stay until we need it to be removed (ortho bands)
-temporary (provisional): protect prepared tooth for crown (thermal/injury/esthetics), come off easily (less adhesive than semi-permanent
-pupal protection: some cements
-made up of: water/oil or resin based
-liquid in cement: is eugenol/phosphoric acid/polyacrylic acid
-dental cements: must be able to withstand hostile environment of oral cavity/change quickly from liquid to solid and must be biocompatible
-hostile environment: poor oral hygiene/ high acid exposure thru diet/ and fermentable carbohydrate exposure

Glass Ionomer Cement (leaches fluoride)
-Uses: water based for crowns/bridges
-Composite: chelating reaction between poly carboxylate molecules in glass ionomer and calcium in teeth=chemical bon (really good adhesion)
-Properties: fluoride (anticaries)
-Manipulation: does not set for 24 hours/do not do anything to restoration
-all cement must be removed or it will act like calculus

Hybrid Ionomer Cement
-Use: water based used for permanent cementation of crowns/bridges/cementing post and orthodontic appliances
-do not work for all ceramic inlays (absorb water and can causes expansion and cracking)
-small amount of fluoride release

Zinc Polycarboxylate Cements
-water based/final cementing of crowns/bridges
-not as strong as other cements/less irritating to pulp
-main ingredient: zinc oxide (powder) mixed with liquid poly acrylic acid and water

Zinc Phosphate Cement
-not often used
-water based cement for final cementation
-Acidic/causes pulpal irritation
-heats up when heated/use a glass slab to mix

Zinc Oxide -Eugenol Cements
-Zinc oxide and eugenol (oil) instead of water based
-sedative pulp effect (obtundent)
-used when exposed tubules
-short term cementing/temporary crowns
-can be used for permanent if a very well fitted crown
-some patients have reactions to eugenol/can use non-eugenol zinc oxide cements
-eugenol is calming pulp

Resin Cements
-used: bonding ceramic and indirect composite crowns (inlays/onlays)-preferred for color (cement blends and matches tooth (can’t see thru restoration)
-dimethacrylic resin and glass filler
-mirco/marco filled/light cured or self curing

Compomer Cement
-use: resin based (cementing cast alloy crowns/bridges or Porcelain to metal (crowns/bridges) or gold inlays or onlays
-do not use on veneers color won’t be compatible
-high retention and bond strength/sustained rechargeable fluoride release

High-Strength Bases
-can be used with cementations
-used for mechanical support for restorations/thermal protection of pulp
-composition: made of glass or hybrid ionomer or polymer reinforced zinc oxide eugenol
-properties: stronger than cements
-thicker and stronger (more powder than liquid)

Temporary fillings
-to protect pulp/reduce pulp inflammation/hold space/provide temporary esthetics until permanent can be placed
-cement: flowable
-filling: putty

Low-Strength Bases
-Barrier for thermal changes/protect pulp
-called a liner, but liners are thinner than bases
-Calcium hydroxide cement: mixed for a base
-Zinc-oxide eugenol: made thinner thicker cement but thinner than filler (would be a base)

Cavity Liners
-thin films that separate dentin from restoration
-protect pulp/block chemicals/fluids
-used to prevent pulpitis (might prevent absess/root canal)
-made of suspended calcium hydroxide organic liquid
-must be covered or will get brown down

Cavity Varnishes
-resin in organic liquid
-solvent evaporates and leaves a film: porous/resin (seals surface of prep)
-even consistency/reduce leakage around margins/wall of restoration

Special Application of Cements
-orthodontic bracket bonding: Resin cement or light cured hybrid ionomer
-metal brackets: bonded with composite
-orthodontic band cementing: glass ionomer/ zinc phosphate cement
-root canal sealers: sealed by gutta purcha or paste

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