Resin luting cements (Word) A type of dental cement Used for cementation of indirect restorations & brackets A summary of five textbooks

1. 1
Resin luting cements
Five textbooks
Craig - Phillips
Art & Sciense
Contemporary fixed prosthodontics
Introduction to dental materials

2. 2
Resin luting cements
Items to be covered
 Uses
 Types
 Types according to method of activation
 Light-cured
 Chemical-cured
 Dual-cured
 Types according to development & the presence of filler
 Unfilled resin
 Composite resin cement
 Types according to adhesion
 Conventional
 Adhesive
 Self-adhesive
 Composition
 Reaction
 Properties
 Degree of conversion
 Cytotoxicity
 Mechanical properties
 Water sorption & solubility
 Film thickness
 Postoperative sensitivity
 Fluoride content & release
 Translucency & esthetics
 Bonding to the tooth structure
 Manipulation
 Resin-to-tooth bonding
 Resin-to ceramic bonding
 Resin-to-metal bonding
 Resin-to-resin bonding
Uses (applications)
Cementation of:
References
Craig's restorative dental materials
Sturdevant's art and science of operative
dentistry
Contemporary fixed prosthodontics
Introduction to dental materials
Phillips' science of dental materials

3. 3
1. Indirect restorations, including veneer, inlay, crown & bridge.
2. Posts: prefabricated posts.
3. Orthodontic brackets.
Note: orthodontic bands are commonly cemented by glass ionomer cements (GIC). (Phillips)
4. Different types of materials, including:
 Ceramics
 Resin composites: laboratory-processed (indirect)
 Metals: if extra retention is needed
5. Resin cements are the material of choice for cementation of ceramic veneers (restorations), why?
(Give reason)
 Translucent, good esthetics & various shades.
 Reduce fracture incidence of ceramics:
 High strength & good bond strength.
Types according to the method of activation
1. Light-cured
2. Chemical-cured (self-cured)
3. Dual-cured: combination of chemical & light activation

4. 4
Contemporary: p. 779
Light-cured resin cements
 Less common, why? (Give reason)
 To avoid the potential incomplete polymerization under a prosthesis.
 Not cure (polymerize) properly with large inlays & crowns, why?(Give reason)
 Light would be unable to penetrate to the full depth of inlay & crown.
 Recommended for bonding the veneer, why? (Give reason)
 More color stability
 More working time

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than the self-cured or dual-cured versions.
 Uses: cementation of:
 Thin translucent prosthesis (ceramic & resin)
 Ceramic veneers
 Orthodontic brackets (Craig)
Chemical-cured resin cement
 Uses: cementation of:
 All types of restorations. (Phillips)
 Metal (cast) restorations: if extra retention is needed.
 Translucent restorations with thickness more than 2.5 mm.
(Phillips, p. 330)
 Inlays: chemical polymerization is preferred, why? (Give reason)
 To ensure maximum polymerization in the less accessible proximal areas.
 Clinical performance: chemical-cured > dual-cured.
(Contemporary: p. 784)
Dual-cured resin cement
 Most commercial products
 Suitable working time
 High degree of conversion even in areas not reached by light. (Craig)
 Slow reaction until exposed to light → at which point the cement hardens rapidly.
 Uses: cementation of translucent restorations with thickness less than
2.5 mm. (Phillips, p. 330)

6. 6
Unfilled resin (1950s)
 Without filler
 High polymerization shrinkage
 Poor biocompatibility
 Unsuccessful
Composite resin cement
 Contains filler.
 Greatly improve properties.
 ↑ filler loading (content) → ↓ resin content → ↓ problems of resin, such as
↓ polymerization shrinkage.
 The filler loading (content) is lower than composite restorative material, why?
(Give reason)
 To ensure low film thickness (required for cementation).
Types of resin cements (Introduction to dental materials, p. 221)
1. Aesthetic light- / dual-cure composite resins (conventional)
2. Adhesive chemical- / dual-cure resin cements
3. Self-adhesive dual-cure resin cements
1. Aesthetic light- / dual-cure composite resins
 Conventional resin cement
 Not adhesive
 Used when aesthetic is important

7. 7
2. Adhesive chemical- / dual-cure resin cements
 Adhesive resin cement
 Improve the adhesive bond to metal
 Still require a dentin bonding agent
3. Self-adhesive dual-cure resin cements
 Self-adhesive resin cement
 Etching, priming & bonding in a single material. (Craig)
= Single step application (Introduction to dental materials, p. 222)
= Not require any pretreatment of the tooth. (Art & Science, p. 159)
= Not require etching & bonding (Phillips)
= Avoid the need for separate etching & bonding. (Craig)
 Simultaneous adhesion to tooth & restoration.
 Become popular, why? (Give reason)
 Simpilicity
 Lowest post-cementation sensitivity.
 Universal adhesive.
 Good bond strength to dentin. (contemporary, p. 781)
Composition
Conventional resin cement
 Very similar composition to restorative composites. (Craig)
 Four major components:
 Organic resin matrix
 Inorganic filler
 Silane coupling agent
 Initiator-accelerator system
Adhesive resin cement
 Combine:

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 MDP with Bis-GMA
 or 4-META & MMA in the liquid, and PMMA in the powder. (Craig)
Notes:
 MDP: Methacryloyloxydecyl dihydrogen phosphate.
 4-META: Methacryloxyethyl trimellitic anhydride.
 Bond chemically to metal oxides.
 High affinity of carboxylic acid & phosphoric acid derivative-containing resins for metal oxides.
Self-adhesive resin cement
 Acidic functional monomer:
 Etch the tooth.
 Based on phosphates & phosphonates.
 Bond to base metal alloys (metal oxides) & ceramics.
 Simultaneous adhesion to tooth & restoration
 Examples:
 10-MDP: Methacryloyloxydecyl dihydrogen phosphate.
 Penta-P: dipentaerythritol pentacrylate phosphate.
 Glycerol dimethacrylate dihydrogen phosphate.
 Alkaline glass: acid neutralizing fillers, such as fluoroalumino silicate (found
in glass ionomers).
 Note: the remaining acidity is neutralized by alkaline glass. (Craig)
 Alkaline amines become inactive in an acidic environment.
 Therefore, a new initiator system has to be developed.
 Each product has its own acid-resistant initiator/accelerator system.
(Introduction to dental materials, p. 222,223)
Commercial products

9. 9
Conventional resin cement
 RelyX ARC (3M/ESPE)
Adhesive resin cement
 Super-Bond C&B (Sun Medical) → contains 4-META.
 Panavia 21 (Kurary) → contains MDP.
Self-adhesive resin cement
 RelyX Unicem (3M/ESPE): contains phosphoric acid-modified methacrylates
 SmartCem2 (Dentsply): contains PENTA.
 MaxCem Elite (Kerr):contains glycerol dimethacrylate dihydrogen phosphate
 Panavia SA Cement Plus (Kurary): contains MDP.
 Speed CEM Plus (Ivoclar Vivadent): contains MDP.
 Solocem (Coltene): contains MDP & 4-META.
Structure of MDP

10. 10
Contemporary: p. 780
Reaction
 Free radical polymerization reaction.
 Activator → activates the initiator → release free radical → initiate the polymerization reaction.
 Acidic groups (phosphate & carboxylate) bind with calcium in hydroxyapatite.
 At later stages, the remaining acidity is neutralized by alkaline glass.
 Anaerobic setting reaction:
 Some commercial products do not set in the presence of oxygen.
 Oxygen barrier (protection): a polyethylene glycol gel (Oxyguard II) can be placed over the
restoration margins
 Oxygen barrier (protection).
 To ensure complete polymerization.
(Contemporary, p. 708)
Properties
 Degree of conversion
 Cytotoxicity
 Mechanical properties
 Water sorption & solubility
 Film thickness

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 Postoperative sensitivity
 Fluoride content & release
 Translucency & esthetics
 Bonding to the tooth structure
Degree of conversion
 In dual-cured cements:
 Light-curing → ↑ degree of conversion →
 ↑ mechanical properties
 ↓ residual monomer → ↓ cytotoxicity of dual-cured cements.
Cytotoxicity
 Unfilled resin > composite resin cement, why? (Give reason)
 In dual-cured resin cements, light-curing → ↓ cytotoxicity, why? (Give reason)
 After 7 days, Bis-GMA-based dual-cured cements are less cytotoxic than zinc polyacrylate.
 Adhesive resin cements are less biocompatible than glass ionomer cement, especially if they (resin
cements) are not fully polymerized.
 Pulp protection: important when the thickness of remaining dentin is less
than 0.5 mm.
 In self-adhesive resins: slightly acid-soluble glass filler reacts with the acidic monomer → increases the
pH to a neutral level.
(Introduction to dental materials, p. 222)
Mechanical properties
 Compressive strength:
 Resin cements (dual- & light-cured) > acid-base cements.
 ↑ Filler content & ↑ degree of conversion → ↑ mechanical properties.
 In dual-cured resin cements, light-curing → ↑ mech prop, why? (Give reason)
 Self-adhesive resin cements have slightly (somewhat) lower mechanical properties than conventional
resin cements.

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Water sorption & solubility
 Virtually insoluble in oral fluids. (Phillips)
 Resin cements < resin-modified glass ionomer.
Notes:
 However, discoloration of the cement line may occur after a prolonged period. (Craig)
 Shrinkage: 2–5%.
 Water sorption:
 Self-adhesive resin cement > conventional, why? (Give reason)
 Unreacted acid groups → ↑ water sorption. (Craig)
Film thickness
 Low viscosity & film thickness. (Craig & Phillips)
 The filler loading (content) is lower than composite restorative material, why?
(Give reason)
 To ensure low film thickness. (Introduction to dental materials, p. 225)
Postoperative sensitivity
 = Post-cementation sensitivity = Post-treatment sensitivity.
(Contemporary: p. 778, 781)
 Self-adhesive resins:
 Lowest incidence of post-cementation sensitivity, why? (Give reason)
 Because the dentin does not need to be etched with phosphoric acid. (Craig)
 Significant advantage.

13. 13
Fluoride content & release
 Self-adhesive resin cement:
 Low fluoride content (around 10%) less than glass ionomer & resin-modified glass ionomer.
 Fluoride release:
 Decrease rapidly with time.
 Its beneficial effects have not been clinically proven.
Translucency & esthetics
 Various shades & translucencies.
 Amines degrade over time, altering the shade of the cement. (Craig)
 Discoloration of the cement line may occur after a prolonged period. (Craig)
 Note: resin cements are the material of choice for cementation of ceramic veneers (restorations), why?
(Give reason)
 Self-adhesive resin cement is not recommended for bonding of ceramic veneers, why?
(Give reason)
 Ceramic veneers are cemented by light-cured resin cements.
 Because of the need for high esthetics.
(Introduction to dental materials, p.223)

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Bonding to the tooth structure
 Micromechanical retention (interlocking) by acid etching.
 Chemical bond between acidic groups (if present) & calcium in tooth structure.
 Self-adhesive resin cement:
 Simultaneous adhesion to tooth & restoration.
 Etching, priming & bonding to tooth in a single material. (Craig)
= Single step application (Introduction to dental materials, p. 222)
= Not require any pretreatment of the tooth. (Art & Science, p. 159)
= Not require etching & bonding (Phillips)
= Avoid the need for separate etching & bonding. (Craig)
 Acidic functional monomer:
 Etch the tooth.
 Based on phosphates & phosphonates.
 Bond to tooth, base metal alloys (metal oxides) & ceramics.
 Simultaneous adhesion to tooth & restoration.
 Bond strength to dentin: comparable to resin cements.
 Bond strength to enamel: less than conventional resin cements.
 Selective etching (with phosphoric acid gel to enamel only) →
↑ bond strength to enamel.
 Notes: enamel bonds are compromised with most self-etching primers.
 This deficiency may be overcome using the “selective etch” technique. (Art & Science,
p. 482)
 Self-adhesive resin cement is not suitable for bonding of orthodontic brackets, why?
(Give reason)
 Because bonding to enamel is less than that achieved with the etch-and-rinse & self-etching
dentin-bonding agents.
(Introduction to dental materials, p.223)

15. 15
Contemporary: p. 779
Phillips: p. 311

16. 16
Manipulation
 The procedure for preparing tooth surfaces remains the same for each system.
 But the treatment of the prosthesis differs depending on the composition of the prosthesis.
(Phillips)
Resin-to-tooth bonding
 Etch-and-rinse or self-etch bonding systems.
 Etch-and-rinse:
 Phosphoric acid etching (35–37%), then rinsing & gentle drying.
 Bonding agent application → form resin tags → ready for luting of restoration with resin
cement.
 Self-adhesive resin cements do not require etching & bonding.
Resin-to ceramic bonding
 Silica-based or glass-matrix ceramics:
 Examples: feldspathic porcelain, leucite-reinforced & lithium disilicate-reinforced ceramics.
 Hydrofluoric (HF) acid etching (5–10%), rinsing & air-drying.
 Silane coupling agent is applied.
 After try-in & prior to applying the silane, cleaning the ceramic surface with isopropyl alcohol,
acetone or phosphoric acid is needed.
 To remove any surface contaminants, such as saliva.
(Introduction to dental materials, p.224)
 For some silane products, it is recommended that a phosphoric acid solution is added to the
silane to hydrolyse it prior to its application.
 Other silane products are already hydrolysed with limited shelf life. (Introduction to
dental materials, p.224)
 Resin cements are the luting agent of choice, why? (Give reason)

17. 17
Introduction to dental materials: p. 223
 Self-adhesive resin cements have lower bond strength to etched glass-matrix ceramics than
conventional resin cements.
(Art & Science, p. 159)
 Oxygen barrier (protection): some products of resin cements do not set in the presence of
oxygen (anaerobic setting reaction), such as
Panavia 21.
 A polyethylene glycol gel (Oxyguard II) can be placed over the restoration margins →
Oxygen barrier (protection).
→ To ensure complete polymerization.
 Note: sandblasting with alumina particles (airborne-particle abrasion): * Immediate lower the
flexural strength of feldspathic porcelains &
lithium disilicate-reinforced ceramics.
* ↓ bond strength when HF is not used. (Art & Science, p. 158)
 The primary source of retention remains the etched porcelain itself.
 Silanation → only a modest ↑ in bond strength.
 However, silanation is recommended, why? (Give reason) → ↓ marginal
leakage & discoloration. (Art & Science, p. 297)
 Polycrystalline ceramics:

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 HF etching does not improve the bond strength, why? (Give reason)
 Because polycrystalline ceramics do not contain a glass matrix.
(Art & Science, p. 158)
 Newest protocols: (Art & Science, p. 158)
 Airborne-particle abrasion.
 Tribochemical silica coating, followed by silane application.
 Primers or silane mixed with functional monomers, such as
10-MDP.
 Micromechanical retention plays more important role than chemical bonding.(Art & Science,
p. 158)
 Zirconia restorations:
 Should be cemented with resin-modified glass ionomer or
self-adhesive resin cement. (Art & Science, p. 508)
 MDP-based resin cements → ↑ adhesion to zirconia.
 Sandblasting is controversial.
 There is a definite risk in the use of air particle abrasion, why? (Give reason)
→ conversion to monoclinic & substantial weakening.
(Art & Science, p. 508)
 Air abrasion with alumina, followed by MDP-based self-adhesive resin cements →
form stable Zr–O–P bonds on the zirconia surface & improve its bond strength. (Craig,
p. 281,282)
 Tribochemical coating using silica-modified alumina particles, followed by silanization
is also efficient. (Craig, p. 281)
 The combination of mechanical and chemical pretreatment is recommended for
bonding to zirconia. (Art & Science, p. 158)
A note on zirconia restorations
 Try-in → contamination with saliva.
 Zirconia has a strong affinity for proteins found in saliva & blood.
 These proteins cannot be removed with phosphoric acid.
 NaOH solution (Ivoclean, Ivoclar Vivadent), for 20 seconds, remove these proteins. (Art & science p.
508)

19. 19
Contemporary: p. 780
Contemporary: p. 781
Resin-to-metal bonding (briefly)

20. 20
 MDP & 4-META: the metal oxides on the surface of base metal & tin-plated noble alloys contributes
to the bond strength (chemical bond) when resin cements contain MDP or 4-META. (Phillips)
 Tin plating improves the retention of noble alloys, why? (Give reason)
 Noble alloys → lack of metal oxide on the surface.
 Tin plating → tin can form tin oxide on the surface.
 Metals are best prepared by sandblasting (airborne-particle abrasion) with alumina particles
 ↑ retention by 64%. (Contemporary, p. 781)
 Creates a roughened higher surface area for bonding.
 Alumina coating → aids in oxide bonding of Phosphate-based adhesive system.
(Contemporary, p. 697)
 Tribochemical silica coating (blasting with silica-coated alumina particles), followed by silane
application is adequate.
 However, it is generally confined to bonding composite resin veneers to alloy castings, why?
(Give reason)
 Because the silane-treated surface may become contaminated before or during the
clinical bonding procedures.
(Contemporary, p. 698)
 Types: (Introduction to dental materials, p. 227)
 Rocatec: laboratory-based system
 Cojet: chair-side system
 Disadvantages: (Introduction to dental materials, p. 228)
 Multiple steps → ↑ likelihood of errors.
 Need special equipment.
 Metal primers are developed, but the research results are inconsistent. (Craig, 280)
 Electrolytic etching is not popular, why? (Give reason)
 Requires high degree of skill & special equipments.
(Introduction to dental materials, p. 225)
 Note: alloy etching and macroscopic retention mechanisms have become obsolete. (Contemporary, p.
697)

21. 21
Resin-to-resin bonding
 Introduction:(Introduction to dental materials, p. 229)
 One might imagine that resin-to-resinbonding should be free of problems, this is, in fact, not
the case.
 In particular, there have been problems of debonding between the luting resin & composite
inlay.
 Oxygen inhibitionlayer does not exist.
 The luting resin has to bond directly to fully cured resins.
 This is similar to repairing a fractured composite restoration with new composite
resin.
 Roughened by grit-blasting (alumina sandlasting).
 Phosphoric acid etching → clean the debris from the surface.
 HF acid is not recommended, why? (Give reason)
 HF causes degradation of the composite surface by etching away the silica glass → leaving a
weak & porous polymer matrix. (Craig, p. 282)
 Tribochemical technique → silica layer, then silane application.
 The problem of resin-to-resin bonding has not yet been resolved satisfactorily, & thus will continue to
be an area of research interest.
(Introduction to dental materials, p. 229)
A note on “try-in” pastes (Craig & Phillips)
 Same shade as the resin cement.
 Help with shade selection.
 Glycerin-based.
 Water-soluble.
 After shade selection → rinsed away with water spray.
A note on temporary cementation

22. 22
 Eugenol-free interim (temporary) luting agent should be used, why?
(Give reason)
 Because eugenol inhibits polymerization of the resin.
References
Sakaguchi R, Ferracane J, Powers J. Craig's restorative dental materials. 14th
ed. St. Louis, Elsevier; 2019. p.
280–282, 289–292.
Ritter AV, Boushell LW, Walter R. Sturdevant's art and scienceof operative dentistry. 7th
ed. St. Louis,
Elsevier; 2019. p. 157–159, 297, 443, 482, 508.
Rosenstiel SF, Land MF, Fujimoto J. Contemporary fixed prosthodontics. 5th
ed. St. Louis, Elsevier; 2016. p.
691, 696–698, 708, 777–781, 784.
Van Noort R, Barbour ME. Introduction to dental materials. 4th
ed. Mosby Elsevier; 2013. p. 221–229.
Anusavice KJ, Shen C, Rawls HR. Phillips' science of dental materials. 12th
ed. St. Louis, Elsevier; 2013.p. 311,
329, 330.