Glass ionomer cement

Introduction
Classification
Composition
Properties Of GIC
Clinical Application Of GIC & GIC In Endodontics
Contraindication Of GIC
Types Of GIC
Recent Advances
Conclusion
References.

1. Glass ionomer cement

2. CONTENTS Introduction Classification Composition Properties Of GIC Clinical Application Of GIC & GIC In Endodontics Contraindication Of GIC Types Of GIC Recent Advances Conclusion References.

3. introduction Glass Ionomer Cement.

4. GIC are more aesthetically pleasing than metallic restoratives . It has wide range of clinical application, anti cariogenic potential & chemical adhesion. ADA specification number: 96 . ISO specification number : 9917

5. definition Glass Ionomer Cement.

6. DEFINITIONS A cement is a substance that hardens to act as a base , liner , filling material or adhesive to bind devices or prosthesis to the tooth structure or to each other. - Philips’ Science Of Dental Materials (12 th Ed)

7. DEFINITIONS An aqueous based material that hardens following an acid base reaction between fluoroaluminosilicate glass powder and poly acrylic acid solution . - Philips’ Science Of Dental Materials (12 th Ed)

8. Other names Glass Ionomer Cement.

9. Glass ionomer-term coined by Wilson & Kent glass -alumino silicate glass particles ionomer -poly carboxylic acid. ISO terminology- poly alkenoate cement .

10. Since its extensive usage to replace the dentin ,has given different names Dentin substitute Man made dentin Artificial dentin Introduced into U.S as ASPA- Alumino silicate polyacrylate

11. History and evolution Glass Ionomer Cement.

12. Wilson and Kent in 1972 produced a first glass that was high in fluoride (G – 200 ) . This cement was originally called as ASPA . ASPA I (De trey Division, Dentsply International) Set sluggishly Susceptible to moisture while setting Very low translucency Nagaraja Upadhya P and Kishore G. Glass Ionomer Cement – The Different Generations. Trends Biomater. Artif. Organs, Vol 18 (2), January 2005.

13. Wilson and Crisp in 1976 they found that optically active d – tartaric acid which modified the cement forming reaction, Clear or slightly opaque . Improve manipulation Extend working time Sharpens the setting rate Therefore it is recognized as reaction controlling additive . This refinement of ASPA I was termed as ASPA II and constituted the first practical glass ionomer cement . Nagaraja Upadhya P and Kishore G. Glass Ionomer Cement – The Different Generations. Trends Biomater. Artif. Organs, Vol 18 (2), January 2005.

14. The first practical glass ionomer cement ASPA II used poly acrylic acid as a cement – forming liquid . However , solutions of poly acrylic acid tend over a period of time to gel when their concentration in water approaches 50% by mass . This is attributed to slow increase in intermolecular hydrogen bonds . Nagaraja Upadhya P and Kishore G. Glass Ionomer Cement – The Different Generations. Trends Biomater. Artif. Organs, Vol 18 (2), January 2005.

15. Wilson and Crisp ( 1974) added methyl alcohol to poly acrylic acid solutions as an agent that inhibits the ordering of structures in solution. This glass ionomer cement was known as ASPA III . Although the gelation of polyacrylic acid was prevented, it was found that the cement stained in the mouth. Nagaraja Upadhya P and Kishore G. Glass Ionomer Cement – The Different Generations. Trends Biomater. Artif. Organs, Vol 18 (2), January 2005.

16. Crisp and Wilson (1977) They synthesized a copolymer of acrylic and itaconic acid , which proved indefinitely stable in a 50% aqueous solution. Reason being that copolymers of acrylic acids would be less regular than simple poly acrylic acid and so less liable to form intermolecular hydrogen bonds . This copolymer was used in ASPA IV . This was the first commercial marketable cement . Nagaraja Upadhya P and Kishore G. Glass Ionomer Cement – The Different Generations. Trends Biomater. Artif. Organs, Vol 18 (2), January 2005.

17. Metal reinforced cements in 1977 by Sced and Wilson Cermet ionomer cements in 1978 by Mc Lean and Glasser Water activated cements, ASPA V in 1982 by Prosser et al. Nagaraja Upadhya P and Kishore G. Glass Ionomer Cement – The Different Generations. Trends Biomater. Artif. Organs, Vol 18 (2), January 2005.

18. classification Glass Ionomer Cement.

19. According To A.D. Wilson & J.W.Mclean (1988) Type I --- Luting cements Type II --- Restorative cements

20. According To Skinners Type I – Luting Type II- Restorative Type III- Liner and base

21. According To Intended Applications Type I – Luting Type II – Restorative Type III – Liner/base Type IV – Pit & fissure sealant Type V – Luting for orthodontic purpose Type VI – Core buildup material Type VII – High fluoride releasing command set Type VIII – Atraumatic restorative treatment Type IX − Pediatric Glass Ionomer cements

22. Newer Classification Traditional glass ionomer a. Type I --- Luting cement b. Type II --- Restorative cements c. Type III --- Liners & Bases Metal modified Glass Ionomer a. Miracle mix b. Cermet cement   Light cure Glass Ionomer HEMA added to liquid   Hybrid Glass Ionomer/resin modified Glass Ionomer a . Composite resin in which fillers substituted with glass ionomer particles b . Precured glasses blended into composites

23. composition Conventional GIC

24. Silica (SiO 2 ) 35.2- 41.9 wt % Glass matrix Increases translucency Alumina (Al 2 O 3 ) 20.1-28.6 wt % Basic filler Increase reactivity of liquid and opacity Alumina Fluoride(AlF 3 ) 1.6-2.4 wt % Flux Calcium Fluoride (CaF 2 ) 15.7- 20.1 wt % Flux Sodium Fluoride( NaF ) 3.6-9.3 wt % Flux Aluminum phosphate (AlPO 4 ) 3.8-12 wt % Glass modifier Improve properties Zirconium Oxide(ZrO 2 ) Trace amount Increase final strength Lanthanum, Strontium, Barium, Zinc oxides Trace amount Imparts radiopacity Materials Used In Dentistry . Mahalaxmi . Chp 15 Pg No.258

25. Materials Used In Dentistry . Mahalaxmi . Chp 15 Pg No.258 Solution of polyacrylic acid / itaconic acid co polymer in water in ratio 2:1. Itaconic acid/maleic acid reduce viscosity of liquid & inhibit gelation caused by inter molecular hydrogen bonding between poly acid molecules. Tartaric acid (5-10%) Improve handling characteristic Increases working time,by prevent premature formation of calciumpoly acrylate chain. Shortens setting time by enhancing formation of aluminum polyacrylate chain.

26. manipulation Glass ionomer cement.

27. Consideration of GIC restorations: Surface of prepared tooth must be clean and dry Consistency of mixed cement must allow complete coating of surface irregularities. Excess cement must be removed at appropriate time. S urface must be finished without excessive drying Protection of surface must be ensured to prevent cracking or dissolution. Phillips Science Of Dental Materials. 11 th edition . Chp 16 Pg No. 476.

28. Surface preparation: A pumice slurry can be used to remove smear layer produced during cavity preparation. Etching with phosphoric acid (apprx34-37%) & Polyacrylic acid (10-20%) for 10- 20 sec , followed by rinsing with water for 20 -30 sec. Phillips Science Of Dental Materials. 11 th edition . Chp 16 Pg No. 476 -477.

29. Preparation of material : P/L ratio for GIC & anhydrous GIC is 1.3:1 & 3.3:1 respectively. . Oil impervious paper pad and stiff agate plastic spatula are used for mixing Stainless steel spatula should not be used as glass particles tends to scratch SS incorporating impurities from spatula to cement mix. Materials Used In Dentistry . Mahalaxmi . Chp 15 Pg No.272-273.

30. Dispensing: Powder: Only the measured scoop provided by the manufacturer should be used to ensure proper P/L ratio. Liquid: First turn the bottle horizontally till the liquid comes to the tip of the nozzle and then invert the bottle vertically and then dispense one whole drop of liquid. Materials Used In Dentistry . Mahalaxmi . Chp 15 Pg No.272-273.

31. Mixing the cement: Divide the powder into two equal increments. First drop should be incorporated in liquid within 5-10 sec without spreading the mix over the pad. The second increment then added and mixed in the folding motion within small areas for next 15 secs. Mixing time should not exceed 45-60 sec Materials Used In Dentistry . Mahalaxmi . Chp 15 Pg No.272-273.

32. GIC in capsules: It should be agitated for 10 secs and dispensed directly over the tooth surface. Finished GIC: Glossy , Wet appearance indicating availability of abundant carboxyl groups on the surface, essential for chemical adhesion to tooth surface. Materials Used In Dentistry . Mahalaxmi . Chp 15 Pg No.272-273.

33. Placement of GIC : Cavity should be slightly overfilled Surface should be covered with plastic matrix for atleast 5 min Further finishing procedure should be delayed for 24 hours. Phillips Science Of Dental Materials. 11 th edition . Chp 16 Pg No. 478.

34. Post operative procedures: Before leaving restoration should be coated with protective agent. Phillips Science Of Dental Materials. 11 th edition . Chp 16 Pg No. 478.

35. Setting reaction Glass Ionomer Cement.

36. Materials Used In Dentistry . Mahalaxmi . Chp 15 Pg No.259. Acid base reaction. Discussed under four heading Dissolution Intial setting Final setting Maturation

37. C raig restorative dental materials 13 th edi . chp 9,pg no. 183

38. C raig restorative dental materials 13 th edi . chp 9,pg no. 183

39. Role of water: I nitially serves as an reaction medium & then slowly hydrates the cross linked matrix(increasing strength of matrix) Initially the water is loosely bounded and can be easily removed by desiccation when exposed to air. Any contamination of water at this stage can lead to dissolution of matrix releasing calcium ions from the polyacrylate chains Materials Used In Dentistry . Mahalaxmi . Chp 15 Pg No.262.

40. Role of water: As setting continues , water hydrates the gel matrix & cannot be removed by desiccation yielding a stable gel structure(tightly bound water) Materials Used In Dentistry . Mahalaxmi . Chp 15 Pg No.262.

41. Role of fluoride: During setting fluoride form a strong , soluble aluminofluoride complexes which prevent premature gelation of polyions by aluminum ions. Fluoride release: 2 mechanisms : Short term initial high fluoride release Long term low fluoride release Materials Used In Dentistry . Mahalaxmi . Chp 15 Pg No.262.

42. Short term initial high fluoride release : Post setting maturation process the fluoride ions are liberated due to formation of aluminum polysalts resulting in high F release initially. Long term low fluoride release: In presence of water , F ions migrate out of cement into surrounding saliva , which causes electrolytic imbalance on surface restoration. On the other hand , when conc of F in saliva is high enough ,the excess F may be incorporated back into GIC (Fluoride Reservoir) Materials Used In Dentistry . Mahalaxmi . Chp 15 Pg No.262.

43. Fluoride release : Fluoride is taken up by tooth structure not only adjacent to a restoration but also in areas up to three millimeters away from the restoration margin and may offer protection to the entire tooth (Retief DH et al in 1984) .

44. Fluoride release : Due to the fluoride released by glass ionomer restorations, fluoride level rises in saliva and also in plaque adjacent to the GIC .( Forss H et al in 1991) Fluoride released from GIC restorations can exert an inhibitory effect on the development of recurrent caries due to diffusion of fluoride ions through the restoration tooth interface .( Seift EJ in 1989.)

45. Set cement: Constitute of hydrogel of calcium, aluminum & fluoroaluminum polyacrylates involving the unreacted glass particles sheathed by weakly bonded siliceous hydrogel layer. Materials Used In Dentistry . Mahalaxmi . Chp 15 Pg No.262.

46. properties Glass ionomer cement.

47. PHYSICAL PROPERTIES OF GIC. Consistency and film thickness: Glass Ionomer Cement .Wilson & Mclean . Conventional filling material Conventional luting material Consistency (mm) 26-34 29-31 Film thickness (µm) 50 24-40

48. Glass Ionomer Cement .Wilson & Mclean . Conventional filling material Conventional luting material Compressive strength(24 hrs )(MPa) 140-195 118-162 Diametral tensile strength ( 24 hrs )(MPa) 9.0-14 6.4-10.9 Flexure strength 8.9- 30.0 5.8-6.6 Strength

49. Glass Ionomer Cement .Wilson & Mclean . Conventional filling material Conventional luting material Creep 24hrs (%) 0.17-0.33 0.32-0.51 Creep: Time dependent plastic strain of material under static load or constant stress .

50. Glass Ionomer Cement .Wilson & Mclean . . Translucency: C 0.7 value- should not exceed 0.55 , to match with translucency of enamel. OPACITY REFLECTANCE VALUE GIC 0.52-0.84 0.55-0.78

51. Coefficient of thermal expansion : 11 ppm/K Thermal conductivity: 0.51-0.72 W/m/K Thermal diffusivity : 0.0022 cm 2 /s

52. Compressive strength (MPA) Diametral tensile strength (MPa) Knoop hardness (KHN) Solubility (ANSI/ADA test) Anticariogenic / Pulp response Fracture toughness (MPa.m1/2) Glass ionomer type II 150 6.6 48 0.4 YES/MILD 0.88 Cermet 150 6.7 39 - YES/MILD 0.51 Hybrid Ionomer 105 20 40 - YES/MILD 1.17

53. Glass Ionomer Cement .Wilson & Mclean . Adhesion : C hemically enamel consist of 98% apatite and 70% in dentine by weight and collagen. Beech (1973) , the interaction between apatite and poly (acrylic acid) produce polyacrylate ions which forms strong ionic bonds with the surface calcium ions of apatite in enamel and dentin. Intermediate layer of calcium and aluminum phosphate and polyacrylates are formed between cement and apatite.

54. Glass Ionomer Cement .Wilson & Mclean . Surface conditioning: It is needed in order to eliminate smear layer formed after cutting tooth as good interfacial contact is important for adhesion. Types of surface conditioners: Citric acid: Polyacrylic acid Tannic acid Ferric chloride Sodium fluoride EDTA

55. biologic PROPERTIES OF GIC. Biocompatible: GIC adhesion to tooth provide excellent marginal seal thus eliminating secondary caries and sustainable release of fluoride confers resistance to caries. Bioactive: When used as bone cements it promotes bone growth

56. EFFECT ON PULP AND CELLS: Freshly mixed cement (pH = 0.9 - 1.6 ) The inflammatory response of pulpal tissue decreases after 30 days The extent of the inflammatory response depends upon the thickness of the residual dentin . The worst pulp reaction occurred under GICs when thickness of the remaining dentin was 0.5 mm or less . Therefore, a sub-lining of fast setting calcium hydroxide is recommended if there is less than 0.5 mm of remaining dentin or there is a possibility of actual pulpal exposure. .

57. INDICATIONS & CONTRAINDICATIONS Glass ionomer cement.

58. CLASS I The use of diamond point for fissure widening Carious dentine is removed using slow round bur .

59. Placement of GIC Covered with Burlew’s dry foil. Excess cement is removed with small round bur and excavator.

60. CLASS II Access gained to approximal lesion using small round diamond bur. Soft metal matrix band is inserted & wedged firmly. Band is burnished toward contact area . Placement of GIC

61. Matrix band burnished over cement to develop contact area. Complete restoration Excess cement is removed with carbide bur and excavator.

62. CLASS III Class III cavity preparation Surface conditioning with 25% polyacrylic acid solution for 10 sec Mylar strips are inserted and GIC is inserted into cavity Tight adaptation of matrix strip and burnishing in order to eliminate excess cement.

63. Matrix removal & application of light cure bonding agent immediately. Complete restortion

64. CLASS V Soft metal type of cervical matrix tugged under the gingiva & GIC injected under matrix Matrix burnished closely to cavity margins to avoid excess cement. Use of sharp knives ,scalers / excavators to trim external margins

65. SANDWICH TECHNIQUE Developed by Mc Lean et al in 1985. Process of placing a GIC between tooth structure and composite. Advantage: It gives benefit of good adhesive quality & fluoride release of GIC and aesthetic quality & durability of composite.

66. CLASS V LAMINATES Class V cavity preparation Fast setting GIC in creamy consisitency Cement is placed in depth of atleast 0.5mm . Fine explorer used to remove excess.

67. CLASS V LAMINATES Enamel and cement etch using 37 % phosphoric acid .after washing and drying application of thin coat light cured bonding agent Composite resin is applied and contoured to position

68. CLASS V LAMINATES Complete restortion Margins are finished using carbide burs. Polishing with abrasive rubber cup and slurry of fine aluminum oxide

69. CLASS III LAMINATES Class III cavity preparation Enamel and cement etch using 37 % phosphoric acid .after washing and drying application of thin coat light cured bonding agent

70. CLASS III LAMINATES Composite resin is applied and contoured to position by using matrix Margins are finished using carbide burs. Polishing with abrasive rubber cup and slurry of fine aluminum oxide Composite resin is applied and contoured to position by using matrix

71. CLASS III LAMINATES Complete restortion

72. FISSURE SEALANT Polyacrylic acid solution applied and raked into fissure with sharp explorer A small bead of cement is picked up on explorer and transferred into fissure Cement raked into fissure Thin sheet wax applied over surface to protect the cement during setting

73. Luting Particle size is in range 4-15µm , to achieve a film thickness of 10-20µm. P/L ratio is 1.5:1. pH -1.8 initially then rises to 4.5

74. LUTING CROWN After surface conditioning with 25% tannic acid the tooth should be lightly dried with absorbent cotton wool. Crown lightly coated with cement taking care to wet out internal line and point angle. Tooth lightly coated with cement & crown seated with finger pressure

75. LUTING CROWN Restoration & cement protected with occlusal indicator wax during setting Complete restoration After setting excess should be careful removed with explorer

76. LUTING POST Paper points used to thoroughly dry canal after surface conditioning Post lightly coated with cement Cement spun into canal with spiral filler

77. LUTING POST Post and core seated with firm finger pressure Complete restoration

78. Atraumatic Restorative Technique Isolation with cotton rolls Obtaining access to carious lesion with hand instrument. Removing carious lesion with excavator Placing GIC restorative material Removal of excess cement Phillips Science Of Dental Materials. 11 th edition . Chp 16 Pg No. 481-482.

79. Core build up Stainless steel post have been cemented into tooth A metal matrix has been placed and cermet cement has been injected Build up is coated with light activated bonding resin Core build up completed

80. ENDODONTICS Glass ionomer cement.

81. Root canal sealing : Pitt ford (1990) introduced the concept of using GIC as an root canal sealing material. Ray & seltzer(1991) filled root canals entirely with modified GIC & concluded it to be easy to use and good adaptation with the canal wall later this material was commercially introduced as Ketac Endo . Saunders et al(1992) used GIC in conjunction with gutta percha and good adaptation to canal wall. Trope & Rey(1992) reported that roots filled with GIC showed increased resistance to vertical root fracture.

82. Retrograde root canal filling: The bond of GIC to dentin allows its application as retrograde root canal filling material. Van Riessen AW & Chong BS(1991) , the sealing ability of the conventional glass ionomer cement was significantly better. The healing areas showed deposition of mineralized tissue . Main obstacle in clinical application was maintenance of dry field .

83. Perforation repair: Fuss & Trope(1996) reported cases of successful perforation repair. Alhadainy and Himel found that light-cured glass ionomer cement exhibited a better seal than amalgam or Cavit when used for furcation perforations repair. Moloney LG ( 1993) , Zvi Fuss et al(2000) , Metal-Modified Glass ionomer Cements.

84. Vertical root fracture Stewart et al (1990) Thought it may bond around fracture line and prevent propagation of fracture. Trope and Rosenberg (1992) used this material to bond a mesio - distally fractured maxillary second molar and reported successful functioning of the tooth .

85. CONTRA-INDICATIONS OF GIC. Class IV carious lesion & fractured incisor. Loss of cuspal areas. Lesion involving large areas on labial enamel where esthetic is not concern.

86. types Glass ionomer cements

87. Resin Modified GIC / Hybrid Ionomer To create longer working time yet quick setting time for immediate finishing concet of RM-GIC was introduced in 1980. Methacrylate components are added in limited amounts so a photo initiated &/or redox curing reaction occur. C raig restorative dental materials 13 th edi . chp 9,pg no. 184-185.

88. Dual cure glass ionomer system : The traditional acid- base reaction of glass ionomer and free radical methacrylate polymerization. Tricure glass ionomer system : RMGIC with additional curing mode. Here in addition to photo initiator , self cure redox initiators are added so that methacrylate polymerization can proceed in absence of light C raig restorative dental materials 13 th edi . chp 9,pg no. 184-185.

89. Powder : Fluoroaluminosilicate glass, Chemical- and/or light-activated initiator(s ) Liquid: Polyacrylic acid, methacrylate monomer, water, activator. Phillips Science Of Dental Materials. 11 th edition . Chp 16 Pg No. 482-484. Composition :

90. Setting reaction resin modified Glass Ionomer Cement.

91. An Atlas of GIC .GJ mount chpt 1.pg no. 6 2 distinct mechanism Acid base reaction Polymerization reaction

92. An Atlas of GIC .GJ mount chpt 1.pg no. 6 Step 1: The polycarboxylic acid ionizes in water in the presence of the fluoroaluminate silicate glass to form a negatively charged carboxylate polymer and protons. .

93. An Atlas of GIC .GJ mount chpt 1.pg no. 6 In Step 2 The protons attack the glass, causing it to release positive ions, e.g., Ca2 + , A13 + , A1F2 + , etc .

94. An Atlas of GIC .GJ mount chpt 1.pg no. 6 In Step 3 These positive ions complex with the negatively charged polycarboxylate polymer to form an cross-linked network. Some of the positive-ions released from the glass are complex in structure and have fluoride present in them, e.g., AlF2 + and alF2 + . .

95. An Atlas of GIC .GJ mount chpt 1.pg no. 6 In Step 3, the polycarboxylate ions replace the fluoride of these complex ions, resulting in the very important fluoride releasing benefit of glass ionomers . Step 4 (light-curing) takes place before the glass-ionomer reaction (Steps 1-3) has gone to completion & thus becomes rigid on demand.

96. Metal rein forced GIC GIC lack toughness & hence cant withstand high stress concentration. To overcome this drawback Simmon in 1983 introduced GIC by physically incorporating silver alloy powder with glass powder (silver alloy admix) Cermet: Introduced by McLean and Gasser in 1987. By fusing glass powder to silver particles through sintering (800°) Phillips Science Of Dental Materials. 11 th edition . Chp 16 Pg No. 479-481.

97. General properties: Wear resistance was reported to be same as that of conventional GIC Initially release fluoride in appreciable amount and decreases substantially overtime. Clinical consideration: Alternative to amalgam restoration in posterior tooth. Exhibit fracture in class II restorations Clinical data indicates this material fall short of expectation Phillips Science Of Dental Materials. 11 th edition . Chp 16 Pg No. 479-481.

98. compomer T he search of material that has capability of fluoride release & durability of composite has lead to introduction of polyacid -modified composite / compomer . It has structural and physical property similar to composite It also has ability to release fluoride & undergo acid base reaction in presence of saliva. Phillips Science Of Dental Materials. 11 th edition . Chp 16 Pg No. 484-486.

99. Powder: Strontium aluminum fluorosilicate Metallic oxides Chemically/ light activated initiators Liquid: Polymerizable methacrylate / carboxylic acid monomers Multifunctional acrylate monomer Water. Phillips Science Of Dental Materials. 11 th edition . Chp 16 Pg No. 484-486.

100. SMART GIC Materials possess a type of ‘smart’ behavior if they can interact with their environment to produce an outcome which is beneficial to their function . The mismatch of thermal expansion and contraction between tooth and restoration leads to stresses at interface and micro leakage

101. SMART GIC Similar behavior with little dimensional changes was observed with dentin on exposure to thermal changes. GIC is the material mimicking the behavior of human dentine . Hence, GIC is described as smart material with respect to thermal behavior.

102. RECENT ADVANCES Glass ionomer cement.

103. Self hardening GIC These are basically, purely chemically activated RMGIC with no light activation at all . Developed mainly for luting purposes . They contain monomers and chemical initiatiors such a the benzoyl peroxide and t- amines to allow self polymerization . Advantages : Packable + Condensable, Easy placement , Improved wear resistance and Solubility in oral fluids is very low Dhoot R et al Advances in Glass Ionomer Cement (GIC): A Review. IOSR-JDMS. Volume 15, Issue 11 Ver. III (November. 2016),

104. Chlorhexidine impregnated GIC It is developed to increase the anticariogenic action of GIC . Still under experimental stage. Dhoot R et al Advances in Glass Ionomer Cement (GIC): A Review. IOSR-JDMS. Volume 15, Issue 11 Ver. III (November. 2016),

105. Fiber Reinforced GIC Incorporation of alumina fibers into the glass powder to improve upon its flexural strength . This technology called the Polymeric Rigid Inorganic Matrix Material It involves incorporation of a continuous network / scaffold of alumina and SiO2 ceramic fibres Increased depth of cure Reduced polymerization shrinkage Improved wear resistance Increase in flexural strength. Dhoot R et al Advances in Glass Ionomer Cement (GIC): A Review. IOSR-JDMS. Volume 15, Issue 11 Ver. III (November. 2016),

106. The Bioactive Glass This idea was developed by Hench and co in 1973. It takes into account the fact that on acid dissolution of glass, there is formation of a layer rich in Ca and PO4 around the glass, such a glass can form intimate bioactive bonds with bone cells and get fully integrated with the bone. Retrograde filling material. For perforation repair . Dhoot R et al Advances in Glass Ionomer Cement (GIC): A Review. IOSR-JDMS. Volume 15, Issue 11 Ver. III (November. 2016),

107. Giomer Giomer utilizes the hybridization of GIC and composite by using a unique technology called the pre-reacted glass ionomer technology. The fluoroaluminosilicate glass is reacted with polyalkenoic acid to yield a stable phase of GIC this pre reacted glass is then mixed with the resin . Dhoot R et al Advances in Glass Ionomer Cement (GIC): A Review. IOSR-JDMS. Volume 15, Issue 11 Ver. III (November. 2016),

108. Amalgomers These are restoratives which are glass ionomer based but with the strength of amalgam . Provide F- release Natural adhesion to tooth structure Good compatibility Prevent shrinkage, creep, corrosion or thermal conductivity problems Exceptional wear characteristics. Dhoot R et al Advances in Glass Ionomer Cement (GIC): A Review. IOSR-JDMS. Volume 15, Issue 11 Ver. III (November. 2016),

109. Hainomers These are newer bioactive materials developed by incorporating hydroxyapatite within glass ionomer powder. These are mainly being used as bone cements in oral maxillofacial surgery and may a future role as retrograde filling material. They have a role in bonding directly to bone and affect its growth and development . Dhoot R et al Advances in Glass Ionomer Cement (GIC): A Review. IOSR-JDMS. Volume 15, Issue 11 Ver. III (November. 2016),

110. Proline Containing Glass Ionomer Cement It is an amino acid-containing GIC had better surface hardness properties. This formulation of fast-set glass ionomer showed increased water sorption without adversely affecting the amount of fluoride release . Considering its biocompatibility, this material shows promise not only as a dental restorative material but also as a bone cement with low cytotoxicity Dhoot R et al Advances in Glass Ionomer Cement (GIC): A Review. IOSR-JDMS. Volume 15, Issue 11 Ver. III (November. 2016),

111. CPP – ACP Containing GIC Here casein phospho peptide-amorphous calcium phosphate incorporated into a glass-ionomer cement. Zaliznaik et al (2013) reported that CPP-ACP containing GIC release not only fluoride ions but also calcium and phosphate ions under acidic condition which helps to inhibit demineralization associated with caries and erosion.

112. Calcium Aluminate GIC A hybrid product with a composition between that of calcium aluminate and GIC, designed for luting fixed prosthesis . The calcium aluminate component is made by sintering a mixture of high-purity Al2O3 and CaO (approximately 1 : 1 molar ratio) to create monocalciumaluminate . The calcium aluminate contributes to a basic pH during curing, reduction in micro leakage, excellent biocompatibility, and long-term stability and strength . Dhoot R et al Advances in Glass Ionomer Cement (GIC): A Review. IOSR-JDMS. Volume 15, Issue 11 Ver. III (November. 2016),

113. NANO Bioceramic Modified GIC The glass ionomer cements containing nanobioceramics are promising restorative dental materials with both improved mechanical properties and improved bond strength to dentin . Higher compressive strength (177–179 mpa ) Higher diametral tensile strength (19–20 mpa ) Dhoot R et al Advances in Glass Ionomer Cement (GIC): A Review. IOSR-JDMS. Volume 15, Issue 11 Ver. III (November. 2016),

114. GICS CONTAINING YBF3 (ytterbium) AND BASO4 Prentice et al., nanoparticles of YbF3(25 nm) and BaSO4 (less than 10 nm) were added to conventional glass-ionomer cement powder The BaSO4 was incorporated to increase the radiopacity of the cement and the YbF3 was a fluoride source that can modify both setting and working times Addition of BaSO4 and YbF3 nanoparticles reduced the working time and the initial setting time, However, the effect was reversed at higher concentrations. Significantly reduced 24 h compressive and surface hardness of glass-ionomers

115. Zirconia Containing GIC A potential substitute for miracle mix . The diametral tensile strength of zirconia containing GIC significantly greater than that of Miracle mix due to better interfacial bonding between the particles and matrix . Dhoot R et al Advances in Glass Ionomer Cement (GIC): A Review. IOSR-JDMS. Volume 15, Issue 11 Ver. III (November. 2016),

116. Niobium Silicate GICs In order to investigate the effect of addition of other glass compositions to conventional GIC glasses , Bertolini et al . Used the following composition as the powder for glass-ionomer cements: 4.5 Sio2 : 3Al2o3 : Xnb2o3 (Niobium) 2CaO (0.1 < X < 2.0). Setting time of the cement pastes increased significantly for Nb containing GIC samples Micro hardness and DTS of the experimental glass-ionomer were decreased

117. Zinc Based Glass-ionomer Cements Boyd et al. Investigated the effect of incorporation of Zn in the composition of glass-ionomer cements Mechanical testing results demonstrated that Z n based GIC had approximately one quarter the strength of their aluminium silicate glass counterparts after 30 days of maturation The flexural strength of these cements was comparable to the flexural strength of conventional GIC.

118. Boric Acid Containing Glass-ionomer Cements Prentice et al., Incorporated boric acid (H3BO3 ) into the glass powder of a glass-ionomer cement in order to evaluate the effect of this acid on the mechanical properties of the glass-ionomer cements Indicated that the incorporation of boric acid was followed by a significant reduction in the compressive strength of the GIC

119. SRO ADDED GLASS-IONOMER CEMENTS The effect of strontium oxide on the mechanical properties of GICS was studied by Deb et al. An increase in the amount of SRO led to increases in both working and setting times, indicating that SRO retarded the rate of reaction The compressive strength of SRO modified cement was increased significantly by (0–5% m/m) SRO addition

120. Glass-ionomers Containing Spherical Silica Filler (SSF) Tjandrawinata et al. Incorporated silica fillers into GIC compositions, and evaluated the various properties of the resulting material. The result of their study demonstrated that the addition of SSF Increased the compressive strength value by 1.1 times Increase of modulus of elasticity was 1.10 to 1.35 times Decreased the 24 h water uptake to 80–90% and reduced the immediate setting shrinkage to 70–79% of the original material.

121. SIC ADDED GLASS-IONOMER CEMENTS The results indicated the SIC( silicone carbide ) added GIC exhibited Improved transverse strength, Enhanced fatigue resistance Improved the long term bond to enamel, while not inhibiting fluoride release Forms a thicker intermediate layer.

122. SIC ADDED GLASS-IONOMER CEMENTS The main disadvantage of SIC added GIC is the risk of SIC particles migrating to vital organs since they do not bond to the matrix of GIC and therefore they can be potentially hazardous to human health

123. CONCLUSION

124. CONCLUSION GIC have come long way since its modest beginning in 1969. With the current level of intensive research on glass ionomers, the deficiencies that exist seem certain to be eliminated, or at least reduced, resulting in an ever improving range of materials .

125. REFERENCES Glass-ionomer cement : Alan D. Wilson / John W. Mclean An atlas of Glass Ionomer Cements – A Clinician’s guide (3rd edition) : Graham J. Mount Craig restorative dental materials 13th edi . chp 9. Phillips Science Of Dental Materials. 11 th edition . Chp 16 . Materials Used In Dentistry . Mahalaxmi . Chp 15.

126. REFERENCES Clinical use of glass ionomer cement: a literature review The Saudi Dental Journal, Volume 6, Number 2, May 1994 Dhoot R et al Advances in Glass Ionomer Cement (GIC): A Review. IOSR-JDMS. Volume 15, Issue 11 Ver. III (November. 2016 ). Nagaraja Upadhya P and Kishore G. Glass Ionomer Cement – The Different Generations. Trends Biomater . Artif . Organs, Vol 18 (2), January 2005.