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. [1] Recent uses of dental cement also include two-photon calcium imaging of neuronal activity in brains of animal models in basic experimental neuroscience. [2]
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 come in capsules and are mechanically mixed using rotating or oscillating mixing machines. [3] Resin cements are not cements in a narrow sense, but rather polymer based composite materials. ISO 4049: 2019 [4] 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 of the commercially available products are class 3 materials, combining chemical- and light-activation mechanisms.
Cement type | Brands (Manufacturer) | Indications | Contra-indications | Advantages | Disadvantages |
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Zinc phosphate |
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Zinc polycarboxylate |
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Glass ionomer (GI) |
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Resin modified glass ionomer (RMGI) |
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Zinc oxide eugenol (ZOE) |
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| When resin cement to be used for permanent cementation |
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Copper cements |
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Resin cements |
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Types | Composition | Setting reaction |
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Zinc phosphate cements |
| 3ZnO + 2H3PO4 +H2O →Zn3(PO4)2 = 4H2O |
Silicophosphate 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 |
Types | Composition | Setting reaction | Advantages | Disadvantages | Applications |
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Zinc oxide/eugenol cements | Supplied 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 |
| Mainly used for lining under amalgam restorations |
Ortho-ethoxybenzoic acid (EBA) cements | Supplied 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 |
| Less retention than zinc phosphate cements | Luting cements primarily |
Calcium hydroxide cements |
| Chelate compounds are formed and chelation is largely due to zinc ions |
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| Used as lining material under silicate and resin-based filling materials |
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.
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. [3]
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. [3]
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:
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 materials are used to cement fixed prosthodontics such as crowns and bridges. Luting cements are often of similar composition to restorative cements; however, they usually have less filler, meaning the cement is less viscous.
Clinical application | Type of cement used |
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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 |
Cements are classified on the basis of their components. Generally, they can be classified into categories:
Cements can be classified based on the type of their matrix:
Based on time of use:
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 three main resin-based cements:
Resin cements come in a range of shades to improve aesthetics. [8]
Zinc polycarboxylate was invented in 1968 and was revolutionary as it was the first cement to exhibit the ability to chemically bond to the tooth surface. Very little pulpal irritation is seen with its use due to the large size of the polyacrylic acid molecule. This cement is commonly used for the installation of crowns, bridges, inlays, onlays, and orthodontic appliances. [10]
Composition:
Adhesion:
Indications for use:
Advantages | Disadvantages |
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Bonds to tooth tissue or restorative material | Difficult to mix |
Long term durability | Opaque |
Acceptable mechanical properties | Soluble in mouth particularly where stannous fluoride is incorporated in the powder |
Relatively inexpensive | Difficult to manipulate |
Long and successful track record | ill-defined set |
Zinc phosphate was the very first dental cement to appear on the dental marketplace and is seen as the “standard” for other dental cements to be compared to. The many uses of this cement include permanent cementation of crowns, orthodontic appliances, intraoral splints, inlays, post systems, and fixed partial dentures. Zinc phosphate exhibits a very high compressive strength, average tensile strength and appropriate film thickness when applies according to manufacturer guidelines. However, issues with the clinical use of zinc phosphate are its initially low pH when applied in an oral environment (linked to pulpal irritation) and the cement's inability to chemically bond to the tooth surface, although this has not affected the successful long-term use of the material. [10]
Composition:
Formerly known as the most commonly used luting agent, zinc phosphate cement works successfully for permanent cementation. It does not possess anticariogenic effects, is not adherent to tooth structure, and acquires a moderate degree of intraoral solubility. However, zinc phosphate cement can irritate nerve pulp; hence, pulp protection is required but the use of polycarboxylate cement (zinc polycarboxylate or glass ionomer) is highly recommended since it is a more biologically compatible cement. [11]
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, urticaria, 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 US 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. [12]
Dental products are specially fabricated materials, designed for use in dentistry. There are many different types of dental products, and their characteristics vary according to their intended purpose.
Zinc oxide eugenol (ZOE) is a material created by the combination of zinc oxide and eugenol contained in clove oil. 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 of metal salts. ZOE can be used as a dental filling material or dental cement in dentistry. It is often used in dentistry when the decay is very deep or very close to the nerve or pulp chamber. Because the tissue inside the tooth, i.e. the pulp, reacts badly to the drilling stimulus, it frequently becomes severely inflamed and precipitates a condition called acute or chronic pulpitis. This condition usually leads to severe chronic tooth sensitivity or actual toothache and can then only be treated with the removal of the nerve (pulp) called root canal therapy. For persons with a dry socket as a complication of tooth extraction, packing the dry socket with a eugenol-zinc oxide paste on iodoform gauze is effective for reducing acute pain. The placement of a ZOE "temporary" for a few to several days prior to the placement of the final filling can help to sedate the pulp. But, ZOE had in vitro cytotoxicity majorly due to release of Zn ions, not eugenol. In spite of severe in vitro cytotoxicity, ZOE showed relatively good biocompatibility in animal study when ZOE was applied on dentin. When ZOE was used as dentin-protective based materials, use of dental composite resin on ZOE was strongly prevented due to its inhibition of resin polymerization through radical scavenging effect. It is classified as an intermediate restorative material and has anaesthetic and antibacterial properties. The exact mechanism of anesthetic effect from ZOE was not revealed perfectly, but possibly through anti-inflammatory effect, modulating immune-cells to less inflamed status.
Dental restoration, dental fillings, or simply fillings are treatments used to restore the function, integrity, and morphology of missing tooth structure resulting from caries or external trauma as well as to the replacement of such structure supported by dental implants. They are of two broad types—direct and indirect—and are further classified by location and size. A root canal filling, for example, is a restorative technique used to fill the space where the dental pulp normally resides.
Dental sealants are a dental treatment intended to prevent tooth decay. Teeth have recesses on their biting surfaces; the back teeth have fissures (grooves) and some front teeth have cingulum pits. It is these pits and fissures that are most vulnerable to tooth decay because food and bacteria stick in them and because they are hard-to-clean areas. Dental sealants are materials placed in these pits and fissures to fill them in, creating a smooth surface which is easy to clean. Dental sealants are mainly used in children who are at higher risk of tooth decay, and are usually placed as soon as the adult molar teeth come through.
In dentistry, a crown or a dental cap is a type of dental restoration that completely caps or encircles a tooth or dental implant. A crown may be needed when a large dental cavity threatens the health of a tooth. Some dentists will also finish root canal treatment by covering the exposed tooth with a crown. A crown is typically bonded to the tooth by dental cement. They can be made from various materials, which are usually fabricated using indirect methods. Crowns are used to improve the strength or appearance of teeth and to halt deterioration. While beneficial to dental health, the procedure and materials can be costly.
Dental composite resins are dental cements made of synthetic resins. Synthetic resins evolved as restorative materials since they were insoluble, of good tooth-like appearance, insensitive to dehydration, easy to manipulate and inexpensive. Composite resins are most commonly composed of Bis-GMA and other dimethacrylate monomers, a filler material such as silica and in most applications, a photoinitiator. Dimethylglyoxime is also commonly added to achieve certain physical properties such as flow-ability. Further tailoring of physical properties is achieved by formulating unique concentrations of each constituent.
In dentistry, inlays and onlays are used to fill cavities, and then cemented in place in the tooth. This is an alternative to a direct restoration, made out of composite, amalgam or glass ionomer, that is built up within the mouth.
A temporary crown is a temporary (short-term) crown used in dentistry. Like other interim restorations, it serves until a final (definitive) restoration can be inserted. Usually the temporary crown is constructed from acrylic resins (monomethacrylate-based/polymethacrylate-based) or, chemical-cure/light cure composite (dimethacrylate-based), although alternative systems using aluminium crown forms are occasionally used. Temporary crowns function to protect the tooth, prevent teeth shifting, provide cosmetics, shape the gum tissue properly, and prevent sensitivity.
Zinc phosphate is an inorganic compound with the formula Zn3(PO4)2. This white powder is widely used as a corrosion resistant coating on metal surfaces either as part of an electroplating process or applied as a primer pigment (see also red lead). It has largely displaced toxic materials based on lead or chromium, and by 2006 it had become the most commonly used corrosion inhibitor. Zinc phosphate coats better on a crystalline structure than bare metal, so a seeding agent is often used as a pre-treatment. One common agent is sodium pyrophosphate.
A glass ionomer cement (GIC) is a dental restorative material used in dentistry as a filling material and luting cement, including for orthodontic bracket attachment. Glass-ionomer cements are based on the reaction of silicate glass-powder and polyacrylic acid, an ionomer. Occasionally water is used instead of an acid, altering the properties of the material and its uses. This reaction produces a powdered cement of glass particles surrounded by matrix of fluoride elements and is known chemically as glass polyalkenoate. There are other forms of similar reactions which can take place, for example, when using an aqueous solution of acrylic/itaconic copolymer with tartaric acid, this results in a glass-ionomer in liquid form. An aqueous solution of maleic acid polymer or maleic/acrylic copolymer with tartaric acid can also be used to form a glass-ionomer in liquid form. Tartaric acid plays a significant part in controlling the setting characteristics of the material. Glass-ionomer based hybrids incorporate another dental material, for example resin-modified glass ionomer cements (RMGIC) and compomers.
A luting agent is a dental cement connecting the underlying tooth structure to a fixed prosthesis. To lute means to glue two different structures together. There are two major purposes of luting agents in dentistry – to secure a cast restoration in fixed prosthodontics, and to keep orthodontic bands and appliances in situ.
In dentistry, amalgam is an alloy of mercury used to fill teeth cavities. It is made by mixing a combination of liquid mercury and particles of solid metals such a silver, copper or tin. The amalgam is mixed by the dentist just before use. It remains soft for a short while after mixing, which facilitates it being snugly packed into the cavity and shaped before it sets hard.
A resin-retained bridge is a bridge replacing a missing tooth that relies for its retention on a composite resin cement. It is one of many available dental restoration methods which is considered minimally invasive and conservative of tooth tissue. The resin-retained-bridge has gone through a number of iterations. Perhaps the best known is the Maryland bridge and other designs used in the past include the Rochette bridge. The five-year survival rate is around 83.6% and the ten-year rate at 64.9%. The case selection is important and as with any dental prosthesis, good oral hygiene is paramount for success. In recent years, the indications for the use of resin-retained-bridges have diminished significantly and there have been changes in the principles underpinning their design. Resin-retained-bridges should be considered when a fixed prosthesis retained by natural teeth is required. The use has been driven by the advent of evidence-based dentistry showing the benefits to patients of reduced tooth preparation and the importance of an intact enamel structure for the long-term health of the teeth. The bridge is currently in favour in the United Kingdom for these reasons. Indeed, recent contemporary research shows resin retained bridges have better success rates than implants and are a cheaper alternative.
Mineral trioxide aggregate (MTA) is an alkaline, cementitious dental repair material. MTA is used for creating apical plugs during apexification, repairing root perforations during root canal therapy, and treating internal root resorption. It can be used for root-end filling material and as pulp capping material. It has better pulpotomy outcomes than calcium hydroxide or formocresol, and may be the best known material, as of 2018 data. For pulp capping, it has a success rate higher than calcium hydroxide, and indistinguishable from Biodentin.
Minimal intervention (MI) dentistry is a modern dental practice designed around the principal aim of preservation of as much of the natural tooth structure as possible. It uses a disease-centric philosophy that directs attention to first control and management of the disease that causes tooth decay—dental caries—and then to relief of the residual symptoms it has left behind—the decayed teeth. The approach uses similar principles for prevention of future caries, and is intended to be a complete management solution for tooth decay.
Dental compomers, also known as polyacid-modified resin composite, are used in dentistry as a filling material. They were introduced in the early 1990s as a hybrid of two other dental materials, dental composites and glass ionomer cement, in an effort to combine their desirable properties: aesthetics for dental composites and the fluoride releasing ability for glass ionomer cements.
Pulp capping is a technique used in dental restorations to protect the dental pulp, after it has been exposed, or nearly exposed during a cavity preparation, from a traumatic injury, or by a deep cavity that reaches the center of the tooth, causing the pulp to die. Exposure of the pulp causes pulpitis. The ultimate goal of pulp capping or stepwise caries removal is to protect a healthy dental pulp, and avoid the need for root canal therapy.
Pediatric crowns are dental crowns that provide full coverage for primary teeth. They can be made of different materials including stainless steel, polycarbonate, zirconium, or composite resin.
Dental cermets, or silver cermets, are a type of restorative material dentists use to fill tooth cavities.
Atraumatic restorative treatment (ART) is a method for cleaning out tooth decay from teeth using only hand instruments and placing a filling. It does not use rotary dental instruments to prepare the tooth and can be performed in settings with no access to dental equipment. No drilling or local anaesthetic injections are required. ART is considered a conservative approach, not only because it removes the decayed tissue with hand instruments, avoiding removing more tissue than necessary which preserves as much tooth structure as possible, but also because it avoids pulp irritation and minimises patient discomfort. ART can be used for small, medium and deep cavities caused by dental caries.
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