Resin Luting cements (2nd edition)

Composite Resin Luting cements (2nd edition) presentation powerpoint
A type of dental cement
Used for cementation of indirect restorations & brackets
A summary of five textbooks

1. 1 Resin Luting Cements

2. 2 Uses Types Composition Reaction Properties Manipulation Items to be covered

3. Cementation of: 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 ) 3 Uses (applications)

4. Cementation of: 4. Different types of materials, including: Ceramics Resin composites : laboratory-processed (indirect) Metals : if extra retention is needed 4 Uses (applications) (continued)

5. 5. Resin cements are the material of choice for cementation of ceramic veneers (restorations ). Reduce fracture incidence of ceramics: * High strength * Good bond strength Translucent , good esthetics & various shades 5 Uses (applications) (continued) W hy?

6. 6 Contemporary : p. 779

7. 1. Light-cured 2. Chemical-cured (self-cured) 3. Dual-cured : combination of chemical & light activation 7 Types According to method of activation

8. Less common. * To avoid the potential incomplete polymerization under a prosthesis . Not cure (polymerize) properly with large inlays & crowns. * Light would be unable to penetrate to the full depth of inlay & crown. 8 Light-cured resin cements W hy? W hy?

9. Recommended for bonding the veneer. * More color stability * More working time than the self-cured or dual-cured versions . Cementation of: * Thin translucent prosthesis (ceramic & resin) * Ceramic veneers * Orthodontic brackets (Craig) 9 Light-cured resin cements W hy? Uses

10. Cementation of: All types of restorations. (Phillips) Metal (cast) restorations: if extra retention is needed . Translucent restorations: if thickness > 2.5 mm . ( Phillips, p. 330 ) 10 Chemical-cured resin cement Uses

11. Cementation of: Inlays : chemical polymerization is preferred. * To ensure maximum polymerization in the less accessible proximal areas. * Clinical performance: chemical-cured > dual-cured. ( Contemporary: p. 784 ) 11 Chemical-cured resin cement W hy? Uses

12. 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 . 12 Dual-cured resin cement

13. Cementation of : T ranslucent restorations: if thickness < 2.5 mm . (Phillips, p. 330 ) 13 Dual-cured resin cement Uses

14. Unfilled resin: without filler Composite resin cement: contains filler 14 Types According to development & the presence of filler

15. ( 1950s ) W ithout filler High polymerization shrinkage Poor biocompatibility Unsuccessful 15 Unfilled resin

16. Contains filler . Greatly improve properties. ↑ filler loading (content) → ↓ resin content → ↓ problems of resin, such as ↓ polymerization shrinkage . 16 Composite resin cement

17. F iller content: less than composite restorative material * To ensure low film thickness (required for cementation). 17 Composite resin cement W hy?

18. 1. Conventional resin cement: not adhesive 2. Adhesive resin cement 3. Self-adhesive resin cement (Introduction to dental materials, p. 221,222) 18 Types According to adhesion

19. Aesthetic: u sed when aesthetic is important L ight- & dual-cure Not adhesive 19 Conventional resin cement

20. Adhesive : i mprove the adhesive bond to metal Chemical- / dual-cure Still require a dentin bonding agent 20 Adhesive resin cement

21. Self-adhesive Not require any pretreatment of tooth: not require etching & bonding Single step application: etching , priming & bonding in a single material Simultaneous adhesion to tooth & restoration 21 Self-adhesive resin cement

22. * Become popular . Simpilicity Lowest post-cementation sensitivity. Universal adhesive. Good bond strength to dentin. (contemporary, p. 781) 22 Self-adhesive resin cement (continued) W hy?

23. Very similar composition to restorative composites. (Craig) Four major components: * Organic resin matrix * Inorganic filler * Silane coupling agent * Initiator-accelerator system 23 Composition Conventional resin cement

24. Combine : * MDP with Bis -GMA (Craig) * or 4-META & MMA in the liquid, and PMMA in the powder . MDP & 4-META bond chemically to metal oxides. Notes : * MDP : contains phosphate group. * 4-META : contains carboxylic acid groups. (Craig) 24 Composition Adhesive resin cement

25. 25 Introduction to dental materials, p. 222

26. Acidic functional monomer: * Etch the tooth. * Based on phosphates & phosphonates. * Bond to base metal alloys (metal oxides) & ceramics . * Simultaneous adhesion to tooth & restoration * Examples: MDP & PENTA: contain phosphate groups. 26 Composition Self-adhesive resin cement

27. 27

28. 28 Structure of MDP

29. 29 Structure of MDP & PENTA

30. Alkaline glass: acid neutralizing fillers, such as fluoroalumino silicate (found in glass ionomers). * Note : the remaining acidity is neutralized by alkaline glass. ( Craig) 30 Composition Self-adhesive resin cement (continued)

31. 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) 31 Composition Self-adhesive resin cement (continued)

32. RelyX ARC (3M/ESPE) 32 Commercial products Conventional resin cement Adhesive resin cement Super-Bond C&B ( Sun Medical) → contains 4-META. Panavia 21 ( Kurary ) → contains MDP.

33. 33 RelyX ARC (3M/ESPE )

34. 34 Super-Bond C&B ( Sun Medical)

35. 35 Panavia 21 ( Kurary )

36. * 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 ( dipentaerythritol pentacrylate phosphate) * SpeedCEM Plus ( Ivoclar Vivadent ): contains MDP . * SoloCem ( Coltene ): contains MDP & 4-META. 36 Commercial products Self-adhesive resin cement

37. 37 RelyX Unicem 2 ( 3M/ESPE )

38. 38 SmartCem2 ( Dentsply )

39. 39 Maxcem Elite ( Kerr )

40. 40 Panavia SA Cement Plus ( Kurary )

41. 41 SpeedCEM Plus ( Ivoclar Vivadent )

42. 42 SoloCem ( Coltene )

43. 43 Contemporary : p. 780

44. 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 . 44 Reaction

45. 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 ) 45 Reaction (continued)

46. 46 Oxyguard II ( Kurary )

47. 47 Properties Degree of conversion Cytotoxicity Mechanical properties Water sorption & solubility Film thickness Postoperative sensitivity Fluoride content & release Translucency & esthetics Bonding to the tooth structure

48. In dual-cured cements: Light-curing → ↑ degree of conversion → * ↑ mechanical properties * ↓ residual monomer → ↓ cytotoxicity of dual-cured cements . 48 Degree of conversion

49. 49 Cytotoxicity Unfilled resin > composite resin cement . In dual-cured resin cements, light-curing → ↓ cytotoxicity . After 7 days, Bis -GMA-based dual-cured cements are less cytotoxic than zinc polyacrylate . W hy? W hy?

50. 50 Cytotoxicity (continued) Adhesive resin cements are less biocompatible than glass ionomer cement, especially if they (resin cements) are not fully polymerized .

51. 51 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) Cytotoxicity (continued)

52. 52 Compressive strength * Resin cements (dual- & light-cured) > acid-base cements. ↑ Filler content & ↑ degree of conversion → ↑ mechanical properties. Mechanical properties

53. 53 In dual-cured resin cements, light-curing → ↑ mech prop. Self-adhesive resin cements have slightly ( somewhat ) lower mechanical properties than conventional resin cements . Mechanical properties (continued) W hy?

54. 54 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 & solubility

55. 55 Water sorption: Self-adhesive resin cement > conventional. * Unreacted acid groups → ↑ water sorption. (Craig ) Water sorption & solubility (continued) W hy?

56. 56 Low viscosity & film thickness . (Craig & Phillips) The filler content is lower than composite restorative material. * To ensure low film thickness. ( Introduction to dental materials, p. 225) Film thickness W hy?

57. 57 = Post-cementation sensitivity = Post-treatment sensitivity. ( Contemporary: p. 778, 781 ) Self-adhesive resins: * Lowest incidence of post-cementation sensitivity. - Because the dentin does not need to be etched with phosphoric acid . (Craig) - Significant advantage . Postoperative sensitivity W hy?

58. 58 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. Fluoride content & release

59. 59 V arious 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). Translucency & esthetics W hy?

60. 60 Self-adhesive resin cement is not recommended for bonding of ceramic veneers. * Ceramic veneers are cemented by light-cured resin cements . * Because of the need for high esthetics. (Introduction to dental materials, p.223 ) Translucency & esthetics ( continued ) W hy?

61. 61 Micromechanical retention (interlocking) by acid etching. Chemical bond between acidic groups (if present) & calcium in tooth structure . Bonding to the tooth structure

62. 62 Self-adhesive resin cement * Not require any pretreatment of tooth: not require etching & bonding * Single step application: etching, priming & bonding in a single material * Simultaneous adhesion to tooth & restoration Bonding to the tooth structure (continued)

63. 63 Acidic functional monomer Etch the tooth. Based on phosphates & phosphonates. Bond to tooth, base metal alloys (metal oxides) & ceramics . Simultaneous adhesion to tooth & restoration . Bonding to the tooth structure (continued)

64. 64 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 . Bonding to the tooth structure (continued)

65. 65 Notes : enamel bonds are compromised with most self-etching primers. This deficiency may be overcome using the “selective etch” technique. (Art & Science, p. 482) Bonding to the tooth structure (continued)

66. 66 Self-adhesive resin cement is not suitable for bonding of orthodontic brackets . * 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 ) Bonding to the tooth structure (continued) W hy?

67. 67 Contemporary : p. 779

68. 68 Phillips: p. 311

69. 69 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)

70. 70 Resin-to-tooth bonding Etch-and-rinse or self-etch bonding systems. Etch-and-rinse * Phosphoric acid etching , then rinsing & air-drying. * Bonding agent application → form resin tags → ready for luting of restoration with resin cement . Self-adhesive resin cements do not require etching & bonding.

71. 71 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.

72. 72 Resin-to ceramic bonding (continued) 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)

73. 73 Resin-to ceramic bonding (continued) 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)

74. 74 Introduction to dental materials: p. 223

75. 75 Resin-to ceramic bonding (continued) Silica-based or glass-matrix ceramics (continued) Resin cements are the luting agent of choice . Self-adhesive resin cements have lower bond strength to etched glass-matrix ceramics than conventional resin cements . ( Art & Science, p. 159 ) W hy?

76. 76 Resin-to ceramic bonding (continued) Silica-based or glass-matrix ceramics (continued) 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. W hy?

77. 77 Resin-to ceramic bonding (continued) Silica-based or glass-matrix ceramics (continued) Note : sandblasting with alumina particles ( airborne- particle abrasion ): * I mmediate lower the flexural strength of feldspathic porcelains & lithium disilicate -reinforced ceramics. * ↓ bond strength when HF is not used. ( Art & Science, p. 158)

78. 78 Resin-to ceramic bonding (continued) Silica-based or glass-matrix ceramics (continued) The primary source of retention remains the etched porcelain itself. Silanation → only a modest ↑ in bond strength. However, silanation is recommended . → ↓ marginal leakage & discoloration. ( Art & Science, p. 297 ) W hy?

79. 79 Resin-to ceramic bonding (continued) Polycrystalline ceramics HF etching does not improve the bond strength. * 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. W hy?

80. 80 Resin-to ceramic bonding (continued) Polycrystalline ceramics (continued) 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.

81. 81 Resin-to ceramic bonding (continued) Polycrystalline ceramics (continued) Zirconia restorations : (continued ) Sandblasting is controversial. There is a definite risk in the use of air particle abrasion, → conversion to monoclinic & substantial weakening . ( Art & Science, p. 508)

82. 82 Resin-to ceramic bonding (continued) Polycrystalline ceramics (continued) Zirconia restorations : (continued ) 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 silane application is also efficient. (Craig, p. 281)

83. 83 Resin-to ceramic bonding (continued) Polycrystalline ceramics (continued) Zirconia restorations : (continued ) The combination of mechanical and chemical pretreatment is recommended for bonding to zirconia. (Art & Science, p. 158 )

84. 84 Resin-to ceramic bonding (continued) 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 )

85. 85

86. 86

87. 87 Contemporary : p. 780

88. 88 Contemporary : p. 781

89. 89 Resin-to-metal bonding ( briefly) 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. Noble alloys → lack of metal oxide on the surface. Tin plating → tin can form tin oxide on the surface . W hy?

90. 90 Resin-to-metal bonding ( continued) 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 )

91. 91 Resin-to-metal bonding ( continued) Tribochemical silica coating (blasting with silica -coated alumina particles), followed by silane application is adequate . 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

92. 92 Resin-to-metal bonding ( continued) Metal primers are developed, but the research results are inconsistent . (Craig, 280) Electrolytic etching is not popular . * 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 ) W hy?

93. 93 Resin-to-resin bonding Introduction: (Introduction to dental materials, p. 229) One might imagine that resin-to-resin bonding 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 inhibition layer 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 .

94. 94 Resin-to-resin bonding (continued) Roughened by grit-blasting (alumina sandlasting ). Phosphoric acid etching → clean the surface . HF acid is not recommended. * 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. W hy?

95. 95 Resin-to-resin bonding (continued) 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)

96. 96 A note on “try-in” pastes Same shade as the resin cement. Help with shade selection. Glycerin-based. Water-soluble. After shade selection → rinsed away with water spray . (Craig & Phillips)

97. 97 Try-in gel (NX3 Nexus, Kerr)

98. 98 A note on temporary cementation Eugenol-free interim (temporary) luting agent should be used. Because eugenol inhibits polymerization of the resin. W hy?

99. 99 References Sakaguchi R, Ferracane J, Powers J. Craig ' s restorative dental materials. 14 th ed. St. Louis, Elsevier; 2019 . p. 280–282, 289–292. Ritter AV, Boushell LW, Walter R. Sturdevant's art and science of operative dentistry. 7 th ed. St. Louis, Elsevier; 2019 . p. 157–159, 297, 443, 482, 508.

100. 100 References (continued) Rosenstiel SF, Land MF, Fujimoto J. Contemporary fixed prosthodontics. 5 th ed. St. Louis, Elsevier; 2016 . p. 691, 696–698, 708, 777 – 781 , 784. Van Noort R, Barbour ME . Introduction to dental materials . 4 th ed. Mosby Elsevier; 2013 . p. 221–229. Anusavice KJ, Shen C, Rawls HR. Phillips ' science of dental materials. 12 th ed. St. Louis, Elsevier; 2013 . p. 311, 329, 330.