Dental cements have a wide range of dental and orthodontic applications. Common uses include temporary restoration of teeth, cavity linings to provide pulpal protection, sedation or insulation, and cementing fixed prosthodontic appliances. Recent uses of dental cement also include two-photon calcium imaging of neuronal activity in the brains of animal models in basic experimental neuroscience.
Traditionally, cements have separate powder and liquid components which are manually mixed. Thus, working time, amount and consistency can be individually adapted to the task at hand. Some cements, such as glass ionomer cement (GIC), can be found in capsules and are mechanically mixed using rotating or oscillating mixing machines. Resin cements are not cements in a narrow sense, but rather polymer-based composite materials. ISO 4049: 2019 classifies these polymer-based luting materials according to curing mode as class 1 (self-cured), class 2 (light-cured), or class 3 (dual-cured). Most commercially available products are class 3 materials, combining chemical- and light-activation mechanisms.
Ideal cement properties High biocompatibility – zinc phosphate cement is considered the most biocompatible material with a low allergy potential despite the occasional initial acid pain (as a consequence of inadequate powder/liquid ratio) Non-irritant – polycarboxylate cement is considered the most sensitive type due to the properties of polyacrylic acid (PAA). Antibacterial properties to prevent secondary caries Provide a good marginal (bacteria-tight) seal to prevent marginal leakage Resistant to dissolution in saliva, or other oral fluid – a primary cause of decementation is the dissolution of the cement at the margins of a restoration High strength in tension, shear and compression to resist stress at the restoration–tooth interface. High compressive strength (minimum 50 microns acc. to ISO 9917-1) Adequate working and setting time Good aesthetics Good thermal insulation properties as a liner under metal restorations Opacity – for diagnostic purposes on radiographs. Low film thickness (maximum 25 microns acc. to ISO 9917-1). Low allergy potential Low shrinkage Retention – if an adhesive bond forms between the cement and the restorative material, retention is greatly enhanced. Otherwise, the retention depends on the geometry of the tooth preparation.Jack L Ferracane, 2001. Materials in Dentistry Second Edition. Colombia
+Comparison of cementsCement typeBrands(Manufacturer)IndicationsContra-indicationsAdvantagesDisadvantagesZinc phosphate DeTrey Zinc (Dentsply) Hoffmann's (Hoffmann Dental Manufaktur) Hy-Bond Zinc (Shofu Dental) Modern Tenacin (L.D. Caulk) Zinc Cement Improved (Mission White Dental) Lining for all filling materials (amalgam, composites) Cementation of inlays, onlays, crowns and bridges made of precious metal, non-precious metal as well as metal ceramic and all-ceramic (zirconium oxide, aluminium oxide and lithium disilicate ceramic) Cementation of implant-supported crowns and bridges Cementation of orthodontic bands Cementation of retention pins and screws Core build-ups Long-term temporary fillings Fillings in deciduous teeth Direct pulp-capping Indirect pulp-capping only if pretreated with copal varnish Cementation of all-ceramic restorations – with compressive strength below 200 MPa Inadequate retention form of tooth preparation Luting of veneers Antibacterial action (initially as strong as penicillin) High biocompatibility Highest elastic modulus Hypoallergenic High compressive Strength Dimensionally stable Opaque Longest clinical experience (over a century) Low film thickness Low cost Pure micro-mechanic adhesion Possible initial acid pain No chemical adhesion Low tensile strength Exothermic during mixing High solubility (in oral fluids)Zinc polycarboxylate Aqua CC (Hoffmann Dental Manufaktur) Durelon (3M Espe) Hy-Bond (Shofu Dental) Tylok Plus (L.D. Caulk) Porcelain restorations Orthodontic bands Cavity liner Metal crowns Metal-ceramic crowns Titanium-based restorations (cement discolouration occurs) Low irritation/ post-op sensitivity Adhesive to tooth structure Sufficient compressive strength Higher tensile strength than zinc phosphate Expands minimally, can thus compensate for polymerisation shrinkage under composite fillings Low pH initially Low resistance to erosion in acidic environment No acid pain Short working timeGlass ionomer (GI) Fuji I (GC America) Ketac-Cem (3M/Espe) Metal and metal-ceramic restorations Porcelain restorations All-ceramic crowns with high strength cores such as alumina or zirconia Orthodontic bands Cavity liners Restoring erosion lesions Allergy (rare) Dentine close to pulp (place suitable liner first) Chemical adhesion to tooth and metal restoration Fluoride release Ease of mixing Good flow Aesthetic Thermal compatible with enamel Low shrinkage Good resistance to acid dissolution Translucency Soluble in water Rapid set – time limitation especially in cementation of several units Moisture sensitivity at set Fluoride release Inherent opacity Low fracture toughness Poor wear resistance Radiolucency Possible pulpal sensitivityResin modified glass ionomer (RMGI) Fuji Plus (GC America) Vitremer Luting (3M/Espe) Advance (L.D. Caulk) Rely X Luting Cavity liners Core buildups Luting cements Crowns Orthodontic appliances All-ceramic crowns – due to uptake of water causing swelling and pressure on the crown Veneer – not retentive enough Dual cure Fluoride release Higher flexural strength than GI Capable of bonding to composite materials Setting expansion may lead to cracking of all-ceramic crowns Moisture-sensitiveZinc oxide eugenol (ZOE) Temp-Bond Fynal (L.D. Caulk) Super EBA (Bosworth) Temporary crowns, bridges Provisional cementation of fixed partial dentures Provisional restoration of teeth Cavity linerWhen resin cement to be used for permanent cementation Neutral pH Good sealing ability Resistance to marginal penetration Obtundent effect on pulpal tissues Weakest of the cements Low strength Low abrasion resistance Soluble (in oral fluids) Little anticariogenic actionCopper cements Doc's Best (Temrex) READY2PROTECT Copperioncement (Hoffmann Dental Manufaktur) Indirect pulp capping in combination with Copal Varnish Minimal invasive caries treatment with modified ART technique Fillings in deciduous teeth Long-term temporary fillings, Lining for all filling materials (polymer-based and amalgam) Core build-ups Bactericidal effect Bacteria-tight sealResin cements Panavia 21 (Kurarary) Multilink Automix SG(Vivadent) RelyX Unicem 2 (3M/ESPE) Maxcem Elite (Kerr) TheraCEM (BISCO) All crown types Bonding fixed partial dentures Inlays Veneers Indirect resin restorations Resin-fiber posts If a ZOE cement has been used for the previous temporary Light cured under a metal crown since it would not cure through the metal Strongest of the cement – highest tensile strength. Least soluble (in oral fluids) High micromechanical bonding to prepared enamel, dentin, alloys, and ceramic surfaces Neutral pH Setting shrinkage – contributing to marginal leakage Difficult sealing Requires a meticulous and critical technique Possible pulpal sensitivity Difficult to remove excess cement
Cements based on phosphoric acid TypesComposition Setting reaction Zinc phosphate cements Usually a powder (zinc oxide with other metallic oxides, e.g. magnesium oxide) and liquid (aqueous solution of phosphoric acid) Zinc oxide or aluminium oxide buffer (up to 10%)3ZnO + 2H3PO4 +H2O →Zn3(PO4)2 = 4H2OSilicophosphate cements (obsolete)Supplied as a powder (zinc oxide and aluminosilicate glass mixture) and liquid (aqueous solution of phosphoric acid with buffers)Forms unconsumed cores of zinc oxide and glass particles enclosed by matrix of zinc and aluminium phosphates.Copper cements Supplied as a powder (zinc oxide and copperions) and liquid (aqueous solution of phosphoric acid)Same as zinc phosphate
Dental cements based on organometallic chelate compounds TypesComposition Setting reactionAdvantages Disadvantages Applications Zinc oxide/eugenol cementsSupplied as two pastes or as a powder (zinc oxide) and liquid (zinc acetate, eugenol, olive oil)A slow chelation reaction of two eugenol molecules and one zinc ion to form zinc eugenolate without moisture. However, setting can be completed fast when water is present.Bactericidal effect due to free eugenol Pulpal damage due to production of exotoxins High solubility in water Interferes with polymerisation process and leads to discolorationMainly used for lining under amalgam restorationsOrtho-ethoxybenzoic acid (EBA) cementsSupplied as a powder (mainly zinc oxide and reinforcing agents: quartz and hydrogenated rosin and liquid o-ethoxybenzoic acid and eugenol)Similar to zinc oxide/eugenol materials Higher powder/liquid ratio can be achieved, so the set material can be strong Lower solubility than zinc oxide/eugenol productsLess retention than zinc phosphate cementsLuting cements primarilyCalcium hydroxide cements Calcium hydroxide in water (water can be substitute by a solution of methyl cellulose in water or a synthetic polymer in volatile organic solvent) Calcium hydroxide is usually supplied as two pastesChelate compounds are formed and chelation is largely due to zinc ions Antibacterial properties Induces formation of secondary dentine layer Setting may be slow due to low viscosity Exothermic setting reaction Relatively low compressive strengthUsed as lining material under silicate and resin-based filling materials
Dental applications Dental cements can be utilised in a variety of ways depending on the composition and mixture of the material. The following categories outline the main uses of cements in dental procedures.
Temporary restorations
Unlike composite and amalgam restorations, cements are usually used as a temporary restorative material. This is generally due to their reduced mechanical properties, which may not withstand long-term occlusal load. Glass ionomer cement (GIC) Zinc polycarboxylate cement Zinc oxide eugenol cement Resin-modified glass ionomer cement (RMGIC)
Bonded amalgam restorations
Amalgam does not bond to tooth tissue and therefore requires mechanical retention in the form of undercuts, slots and grooves. However, if insufficient tooth tissue remains after cavity preparation to provide such retentive features, a cement can be utilised to help retain the amalgam in the cavity.
Historically, zinc phosphate and polycarboxylate cements were used for this technique; however, since the mid-1980s, composite resins have been the material of choice due to their adhesive properties. Common resin cements utilised for bonded amalgams are RMGIC and dual-cure resin-based composite.
Liners and pulp protection
When a cavity reaches close proximity to the pulp chamber, it is advisable to protect the pulp from further insult by placing a base or liner as a means of insulation from the definitive restoration. Cements indicated for liners and bases include: Zinc oxide eugenol Zinc polycaroxylate Resin-modified glass ionomer cement (RMGIC) Pulp capping is a method to protect the pulp chamber if the clinician suspects it may have been exposed by caries or cavity preparation. Indirect pulp caps are indicated for suspected micro-exposures, whereas direct pulp caps are placed on a visibly exposed pulp. To encourage pulpal recovery, it is essential to use a sedative, non-cytotoxic material such as setting calcium hydroxide cement.
Luting cements
Luting materials are used to cement fixed prosthodontics such as crowns and bridges. Luting cements are often of similar composition to restorative cements; however, they typically have less filler, resulting in a less viscous cement. Resin-modified glass ionomer cement (RMGIC) Glass ionomer cement (GIC)