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Dental cements are a group of materials with 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.[1]

Traditional cements are presented as separate powder and liquid components, manually mixed to form a viscous liquid, which then sets to form a brittle solid after application on the required treatment surface. More advanced cements, such as GIC, can also be presented in capsule form and are mechanically mixed using rotational or oscillating mixing machines.[2]

Contents

Ideal cement propertiesEdit

  • Non irritant – many cements are acidic and therefore an irritant to the pulp. However, on setting there is a rapid increase in pH and polycarboxylate cements are considered to be the most biocompatible of the cements due to its most rapid rise in pH.
  • Provide a good marginal seal to prevent marginal leakage.
  • Resistant to dissolution in saliva, or in any oral fluid – a primary cause of failure of cements is due to dissolution of the cement at the margins of a restoration.
  • High strength in tension, shear and compression to resist stresses at the restoration-tooth interface.
  • Adequate working and setting times.
  • Good aesthetics.
  • Good thermal and chemical resistance.
  • Opacity – for diagnostic purposes on radiographs.
  • Low film thickness (ideally 25 microns).
  • Retention – if an adhesive bond can be created between the cement and the restorative material, this can greatly enhance the retention. Otherwise, the retention is governed by the geometry of the tooth preparation.[3][page needed]

The following table describes the properties of each type of cement in more detail:  

Cement type Brands Available

(Manufacturer)

Indications Contra-indications Advantages Disadvantages
Zinc phosphate Hy-Bond Zinc Phosphate Cement (Shofu Dental)

Modern Tenacin (L.D. Caulk)

Zinc Cement Improved (Mission White Dental)

Long span bridges

Metal Crowns

Metal-Ceramic Crowns

Feldspathic

Porcelain jacket crowns

Orthodontic bands

Cavity liner

All-ceramic restorations – due to setting expansion

Inadequate retention form of tooth preparation

Highest elastic modulus

High Compressive Strength

Low film thickness

Low cost

Acidic – possible pulpal irritation

Lack of antibacterial action

Brittle

Lack of adhesion

Low tensile strength

Provides only mechanical seal

Exothermic during set

High solubility (in oral fluids)

Low hardness

Zinc polycarboxylate Hy-Bond Polycarboxylate Cement (Shofu Dental)

Tylok Plus (L.D. Caulk)

Durelon

Porcelain restorations

Orthodontic bands

Cavity liner

Metal crowns

Metal-ceramic crowns

Titanium based restorations (cement discolouration occurs) Antibacterial

Low irritation

Adhesive to tooth structure

Sufficient compressive strength

Higher tensile strength than Zinc Phosphate

Low post-op sensitivity

Low pH initially

Low resistance to erosion in acidic environment

Short working time

Glass 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)

Adhere to teeth and metal

Fluoride release

Ease of Mixing

Good flow

Cheap

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

Brittle

Inherent opacity

Low fracture toughness

Poor wear resistance

Radiolucency

Possible pulpal sensitivity

Resin 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 sensitive  

Zinc oxide eugenol Temp-Bond

Fynal (L.D. Caulk)

Super EBA (Bosworth)

Temporary crowns, bridges

Provisional cementation of fixed partial dentures

Provisional restoration of teeth

Cavity liner

When 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 action

Resin cements Panavia 21 (Kurarary)

Dual Cement (Vivadent)

Rely X Unicem (3M/Espe)

All crown types

Bonding fixed partial dentures

Inlays

Veneers

Indirect resin restorations

Resin-fibre 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 cements – 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

Dental applicationsEdit

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 restorationsEdit

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.[2]

Bonded amalgam restorationsEdit

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.[2]

Liners and pulp protectionEdit

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
  • 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 place on a visibly exposed pulp. In order to encourage pulpal recovery, it is important to use a sedative, non-cytotoxic material such as Setting Calcium Hydroxide cement.

Luting cementsEdit

Luting materials are used to cement fixed prosthodontics such as Crowns & Bridges. Luting cements are often of similar composition to restorative cements, however they usually have less filler meaning the cement is less viscous.

  • RMGIC
  • GIC
  • Zinc Polycarboxylate cement
  • Zinc oxide eugenol luting cement

Summary of clinical applicationsEdit

Clinical application Type of cement used
Crowns
Metal Zinc phosphate, GI, RMGI, self or dual cured resin *
Metal ceramic Zinc phosphate, GI, RMGI, self or dual cured resin *
All ceramic Resin cement
Temporary crown Zinc oxide eugenol cement
3/4 crown Zinc phosphate, GI, RMGI, self or dual cured resin *
Bridges
Conventional Zinc phosphate, GI, RMGI, self or dual cured resin *
Resin bonded Resin cement
Temporary bridge Zinc oxide eugenol cement
Veneers Resin cement
Inlay Zinc phosphate, GI, RMGI, self or dual cured resin *
Onlay Zinc phosphate, GI, RMGI, self or dual cured resin *
Post and core
Metal post Any cement which is non-adhesive (NOT resin cements)
Fibre post Resin cement
Orthodontic brackets Resin cement
Orthodontic molar bands GI, zinc polycarboxylate, composite

Composition and classificationEdit

ISO classification Cements are classified on the basis of their components. Generally, they can be classified into categories:

  • Water-based acid-base cements: zinc phosphate (Zn3(PO4)2), Zinc Polyacrylate(Polycarboxylate), glass ionomer (GIC). These contain metal oxide or silicate fillers embedded in a salt matrix.
  • Non-aqueous/ oil bases acid-base cements: Zinc oxide eugenol and Non-eugenol zinc oxide. These contain metal oxide fillers embedded in a metal salt matrix.
  • Resin-based: Acrylate or methacrylate resin cements, including the latest generation of self-adhesive resin cements that contain silicate or other types of fillers in an organic resin matrix.

Cements can be classified based on the type of their matrix:

Resin-based cementsEdit

These cements are resin based composites. They are commonly used to definitively cement indirect restorations, especially resin bonded bridges and ceramic or indirect composite restorations, to the tooth tissue. They are usually used in conjunction with a bonding agent as they have no ability to bond to the tooth, although there are some products that can be applied directly to the tooth (self-etching products).

There are 3 main resin based cements;

  • Light-cured – required a curing lamp to complete set
  • Dual-cured – can be light cured at the restoration margins but chemically cure in areas that the curing lamp cannot penetrate
  • Self-etch – these etch the tooth surface and do not require an intermediate bonding agent

Resin cements come in a range of shades to improve aesthetics.[5]

Zinc polycarboxylate cementsEdit

Composition:

  • Powder + liquid reaction
  • Zinc oxide (powder) + poly(acrylic) acid (liquid) = Zinc polycarboxylate
  • Zinc polycarboxylate is also sometimes referred to as zinc polyacrylate or zinc polyalkenoate
  • Components of the powder include zinc oxide, Stannous fluoride, magnesium oxide, silica and also alumina
  • Components of the liquid include poly(acrylic) acid, itaconic acid and maleic acid.

Adhesion:

  • Zinc polycarboxylate cements adhere to enamel and dentine by means of chelation reaction.

Indications for use:

  • Temporary restorations
  • Inflamed pulp
  • Bases
  • Cementation of crowns[5]
Advantages Disadvantages
Bonds to tooth tissue or restorative material Difficult to mix
Long term durability Opaque
Acceptable mechanical properties Soluble in moth particularly where stannous fluoride is incorporated in the powder
Relatively inexpensive Difficult to manipulate
Long and successful track record ill-defined set

Known contra-indications of dental cementsEdit

Dental materials such as filling and orthodontic instruments must satisfy biocompatibility requirements as they will be in the oral cavity for a long period of time. Some dental cements can contain chemicals that may induce allergic reactions on various tissues in the oral cavity. Common allergic reactions include stomatitis/dermatitis, uticaria, swelling, rash and rhinorrhea. These may predispose to life threatening conditions such as anaphylaxis, oedema and cardiac arrhythmias.

Eugenol is widely used in dentistry for different applications including impression pastes, periodontal dressings, cements, filling materials, endodontic sealers and dry socket dressings. Zinc oxide eugenol is a cement commonly used for provisional restorations and root canal obturation. Although classified as non-cariogenic by the Food and Drug Administration, eugenol is proven to be cytotoxic with the risk of anaphylactic reactions in certain patients.

Zinc oxide eugenol constituents a mixture of zinc oxide and eugenol to form a polymerised eugenol cement. The setting reaction produces an end product called zinc eugenolate which readily hydrolyses producing free eugenol that causes adverse effects on fibroblast and osteoclast-like cells. At high concentrations localised necrosis and reduced healing occurs whereas for low concentrations contact dermatitis is the common clinical manifestation.

Allergy contact dermatitis has been proven to be the highest clinical occurrence usually localised to soft tissues with buccal mucosa being the most prevalent. Normally a patch test done by dermatologists will be used to diagnose the condition. Glass Ionomer cements have been used to substitute zinc oxide eugenol cements (thus removing the allergen), with positive outcome from patients.[6]

ReferencesEdit

  1. ^ "dental cement". TheFreeDictionary.com. Retrieved 2017-11-21.
  2. ^ a b c J., Bonsor, Stephen (2013). A clinical guide to applied dental materials. Pearson, Gavin J. Amsterdam: Elsevier/Churchill Livingstone. ISBN 9780702031588. OCLC 824491168.
  3. ^ Template:Cite Jack L Ferracane, 2001. Materials in Dentistry Second Edition. Colombia
  4. ^ {{cite web According to ISO 9917-1:2007 Dental cements classified as: a. Luting cements b. Bases or lining C. Restoration | last =Spiller | first =Martin S. | title =Composite materials | publisher =Doctorspiller.com | date =2000 | url =http://www.doctorspiller.com/dental_materials.htm#Resin%20(Composite)%20Cements | accessdate =2008-08-11 |archiveurl =https://web.archive.org/web/20080730030225/http://www.doctorspiller.com/dental_materials.htm#Resin%20(Composite)%20Cements |archivedate =2008-07-30}}
  5. ^ a b Bonsor, Stephen; Pearson, Gavin (2013). A Clinical Guide to Applied Dental Materials. Elsevier. pp. 167, 168 and 169.
  6. ^ Template:Cite Deshpande A N, Verma S, Macwan C. January 2014. Allergic Reaction Associated with the use of Eugenol Containing Dental Cement in a Young Child. Research Gate.
  • Acid-base Cements (1993) A. D. Wilson and J.W. Nicholson