restorative GICs... an update on current products Issue Newer conventional GIC >> (cont) Newer conventional GIC >> Conventional GICs >>

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1 Issue glass-ionomer cement update an update on current products restorative GICs... Newer conventional GIC >> Chemfil Rock (Dentsply) Newer conventional GIC >> (cont) Chemfil Rock (cont) Summary: An interesting material with high flexural strength and packable placement characteristics. Independent clinical evaluations needed. 7 Flexural strength 2 Compressive strength 3 N/mm Manufacturer: Dentsply. Type: High viscosity, auto-cure GIC. The powder 8 contains a zinc-modified fluoroaluminosilicate glass. The liquid includes 9 polycarboxylic acid, itaconic acid, tartaric acid and water. 1 Comment: The product has a new zinc formulation designed to improve early strength and ease of handling. During the first stage of the setting reaction of conventional GICs the calcium or strontium ions released from the glass particles form complexes with the acid component. 2 Then, over the subsequent maturation period, the less mobile aluminium ions released from the glass particles, form more rigid complexes with the polyacids. With Chemfil Rock, in the first stage of the setting reaction, it appears that the zinc component quickly forms stronger complexes with the polyacids than obtained with either calcium or strontium. The early strength of the material is thereby enhanced. 2 No reports of independent clinical trials found. Advantages: High flexural strength. 2 Good compressive strength. 3 Produces a good surface free of irregularities. 2 Disadvantages: Less surface hardness than some auto-cure GICs. 2 No independent clinical evaluations. N/mm Chemfil Rock Fuji IX GP Fast Vickers hardness 2 Chemfil Rock Fuji IX GP Fast Conventional GICs >> Fuji IX GP (Fast) (GC) Chemfil Rock Fuji IX Contrast white shade of Chemfil Rock. Manufacturer: GC. Type: High viscosity, auto-cure GIC. The powder contains a strontium aluminofluorosilicate glass. The liquid contains polyacrylic acid, polybasic carboxylic >

2 recent developments from laboratory and clinical testing Fuji IX GP (Fast) (cont) acid and water. 4 Comment: The product was originally developed for the Atraumatic Restorative Technique (ART) and has been widely used since then. The earlier version, Fuji IX GP, had comparable physical properties. The main differences are that Fuji IX GP (Fast) has a quicker setting time and improved hardness. 5 > After 6 years, when used as a restorative material in approximo-occlusal (Class 2) cavities: 6 No secondary caries were seen. There were no failures due to bulk fracture or excessive wear. The main problem was material loss in the contact area of some approximal surfaces and a subsequent undermining of the marginal ridge. > When used as a pit and fissure sealant in a 5-year trial, the retention rate was not high. However, the material demonstrated a residual anti-caries effect approximately 4 times better than the resin sealant used in the same trial. 7 Physical properties: Similar to (3M Espe) the other longstanding high viscosity, auto-cure GIC (see page yy). Summary: A long-standing material which has been extensively evaluated in clinical trials. Has set the standard for other GICs in this category. Fuji IX GP Extra (GC) Fuji IX GP Extra (cont) Manufacturer: GC. Type: High viscosity, auto-cure GIC. Its composition is similar to Fuji IX GP (Fast) except that the aluminofluorosilicate glass has been modified to give a greater translucency, faster setting time and higher fluoride release. 8 Physical properties: Similar to Fuji IX GP (Fast) except that the material is less radiopaque. 8 Fuji IX GP Extra + G-Coat Plus + A light-cured, nanofilled coating material (G-Coat Plus - GC) has been introduced to protect the surface of a GIC, such as Fuji IX GP Extra, during the early setting stages. Its self-adhesive component and low viscosity are designed to effectively seal the GIC surface. 9 The addition of colloidal silica is intended to protect against abrasive wear. (In some markets the combination of G-Coat Plus and Fuji IX GP Extra (GC) is marketed under the name Equia). G-Coat Plus Fuji IX GP Extra G-Coat Plus is designed to provide longer lasting protection to a GIC surface than some of the traditional surface-protective agents.

3 glass-ionomer cement update an update on current products Fuji IX GP Extra + G-Coat Plus A clinical study has been undertaken to determine whether the combination of G-Coat Plus and Fuji IX GP Extra can change the high-viscosity GIC from being a longer-term interim restorative material into a more permanent one for Class I and 2 cavities. 1 After approximately 24 months, some wear was observed in around 1% of the occlusal-surface restorations and just under half of the multiplesurface restorations. In the latter cases, a loss of tight approximal-surface contacts was the main problem. The possibility is that approximal surface contact areas, because of their location, may not have received an adequate application of G-Coat Plus after restoration placement. Summary: It appears that the approximal surface contact area remains the longerterm problem site for Class 2 GIC restorations. However, it is not clear whether G-Coat Plus adequately covered these sites in the clinical trial of Fuji IX GP Extra. Note: Laboratory studies assessing the physical properties of Fuji IX GP Extra in combination with G-Coat Plus (Equia) have been deliberately omitted from this review. The test methods used have either not been given fully (as in the case of Abstracts) or the methodology bears no obvious relationship to the clinical situation. For example, in published tests of flexural strength, the coating was placed underneath the specimen and not on the surface facing the load. 2,9,11 This appears to be the equivalent to placing the coating at the base of a Class I restoration and not on the surface Fil Plus (3M Espe) Manufacturer: 3M Espe. Type: Auto-cure GIC. Powder reported to contain a calcium aluminium lanthanum fluorosilicate glass and strontium. Liquid reported to contain acrylic and maleic acids copolymer, tartaric acid, benzoic acid and water. 12 Comment: One of the early restorative GICs that has stood the test of time. Comparable caries-preventive effect to resinmodified GIC. 13 As effective as resin-based materials when used as a pit and fissure sealant. 14 Summary: A long-standing product for use in non-stress-bearing sites. Compressive strength is lower than (3M Espe). 15 However, flexural strength and fracture toughness are similar to. 15,16 Compressive strength Flexural strength 15 cracks wear Fil Fil K 1 C 1. Fracture toughness 16 Protection of a GIC surface from the time of placement to material maturation has the potential to reduce subsequent problems such as cracking and surface wear..5 Fil

4 recent developments from laboratory and clinical testing (3M Espe) (cont) Knoop hardness 2 Fracture toughness 16 KHN 7 45 K 1 C 1. Premise Filtek Manufacturer: 3M Espe. Type: Auto-cure GIC. Powder reported to contain a calcium aluminium lanthanum fluorosilicate glass and strontium. Liquid reported to contain acrylic and maleic acids copolymer, tartaric acid, benzoic acid and water. 12 Comment: Another long-standing product. Available in two versions. The faster setting version, Quick Aplicap, is illustrated above. Higher caries-preventive effect than amalgam in permanent teeth. No difference in primary teeth. 17 As effective as resin-based materials when used as a pit and fissure sealant. 18 Same or higher survival rate than amalgam when used in ART restorations (Class I, 2 and 5) in permanent teeth. 19 Physical properties: Similar to Fuji IX GP (GC) the other longstanding high viscosity, auto-cure GIC (see below). Summary: For all practical purposes, a material with comparable physical properties to Fuji IX GP (GC). Compressive strength 2 Flexural strength Fuji IX 2 1 Fuji IX Fuji IX Riva Self Cure (SDI) Manufacturer: SDI. Type: Auto-cure GIC. Powder contains a fluoroaluminosilicate glass. Liquid contains polyacrylic acid and tartaric acid. 21 Comment: Product is available in either a standard or high viscosity version. Encapsulation as used in the current product found conducive to ART restoration survival in a 16-month trial. 22 Physical properties: Physical properties in terms of flexural strength and Knoop hardness found to be below those of Fuji IX GP (GC) but no significant difference in terms of compressive strength. 2 Fil Plus Summary: A material with high early fluoride release. Some physical properties (flexural strength and Knoop hardness) of standard viscosity version found to be lower than Fuji IX GP (GC). Results with the higher viscosity version not found.

5 glass-ionomer cement update an update on current products Newer resin-modified GIC >> Nano (3M Espe) Newer resin-modified GIC >> (cont) Nano (cont) Summary: A product that includes more resin as well as nanofillers and nanoclusters. Further clinical studies are needed to show if there are still problems with marginal integrity as seen in the one trial to date Flexural strength 29 Flexural modulus 29 GPa 12 Manufacturer: 3M Espe. Type: A light-curing resin-modified GIC in a paste/paste system. Contains a fluoroaluminosilicate glass plus nanofillers and nanoclusters. Resins present include HEMA, PEGDMA, BISGMA and TEGDMA.* 23,24 Comment: Nano is sometimes referred to as a nanoionomer. In an approach designed to provide improved aesthetics, wear resistance and high initial polish, the product contains increased resin plus nanoparticles and nanoclusters. No hand mixing or trituration of the capsule is required. A 12-month study in which Nano was used to restore non-carious cervical lesions found a significant increase in enamel margin staining and deteriorating marginal adaptation over the period of the trial. 24 Advantages: Good surface gloss and low surface roughness. 25 Good resistance to red wine and tea stains. 26 Fluoride release similar to established resinmodified GICs. 27 Disadvantages: Enamel margins of a cavity may need to be selectively etched to improve marginal quality of restorations when this product used. 24 Water absorption could be a problem. Product found to keep expanding almost 6 months after being placed in cavities in extracted teeth and exposed to water. 28 * HEMA = 2-hydroxyethylmethacrylate. PEGDMA = polyethylene glycol dimethacrylate. BISGMA = bisphenol A diglycidyl ether dimethacrylate. TEGDMA = triethylene glycol dimethacrylate. 5 Fuji ll LC Nano Compressive strength Nano Fuji ll LC Fuji ll LC (GC) 6 Nano Fuji ll LC 29 Fracture toughness 29 m 1/ Resin-modified GICs >> Manufacturer: GC. Type: A light-cured resin-modified GIC. Contains an aluminofluorosilicate glass, polyacrylic acid and HEMA. 3 Comment: One of the longer-standing resinmodified GICs. Nano Fuji ll LC

6 recent developments from laboratory and clinical testing Resin-modified GICs >> (cont) Fuji ll LC (cont) Has shown a higher reduction of demineralisation and at least the same caries-protective effect as resin pit and fissure sealants. 2 Has shown a good retention rate when used to restore non-carious cervical lesions. 18,31 Advantages: Physical properties basically similar to other restorative resin-modified GICs. 16,29,33 Fluoride release similar to established resinmodified GICs. 33 Disadvantages: Increase in the roughness of the surface with time seen in clinical studies. 34 Resin-modified GICs >> (cont) Photac Fil Quick Aplicap (cont) Disadvantages: No longer-term clinical evaluations found. Summary: A product that has a long history of use. However, only limited independent information was found on physical properties and clinical performance. Vitremer (3M Espe) Summary: A reliable material with a good clinical track record. Main weakness is the increasing roughness of the surface with time. Photac Fil Quick Aplicap (3M Espe) Manufacturer: 3M Espe Type: A light-cured resin-modified GIC. Contains acrylic and maleic acids, HEMA and a sodiumcalcium aluminium lanthanum fluorosilicate glass. 35 Comment: A long-standing resin-modified GIC. Designed for situations where rapid application is needed. Has shown a comparable caries-preventive effect to conventional GICs. 13 Advantages: Upper level of fracture toughness amongst resin-modified GICs. 16 Good fluoride release. 33 Manufacturer: 3M Espe Type: A light-cured resin-modified GIC. Contains polyacrylic and itaconic acids, HEMA and a fluoroaluminosilicate glass. 36 Comment: A long-standing resin-modified GIC. Now being promoted as a core-build-up material as well as a restorative material. Has shown a caries-preventive effect similar to or superior to resin composite. 37 Very good longer-term retention when used in non-carious cervical lesions. 38 Advantages: Adequate fracture toughness and compressive strength. 16,33 Satisfactory fluoride release. 33 Disadvantages: Not as strong as resin composite for core buildups. Summary: A product that has stood the test of time. Has a good clinical record as a restorative material for non-carious cervical lesions, as a pit and fissure sealant, and for use in the ART technique.

7 glass-ionomer cement update an update on current products References >> 1. Manufacturer s data. ( Science section download). 2. Zoergiebel J, Ilie N. Evaluation of a conventional glass ionomer cement with new zinc formulation: effect of coating, aging and storage agents. Clin Oral Investig. 212 May 2. [Epub ahead of print] 3. Cabral RJ, Molina GF, Lascano L, Zaya LM, Mazzola I, Frencken J. Compressive strength of new capsulated GIC s for atraumatic restorative treatment. J Dent Res 212 (Spec Iss B) Abstr USAF Dental Evaluation & Consultation Service. Fuji IX GP glass ionomer. Project (9/98) 5. Yap AU, Pek YS, Cheang P. Physico-mechanical properties of a fast-set highly viscous GIC restorative. J Oral Rehabil. 23;3: Scholtanus JD, Huysmans MC. Clinical failure of class-ii restorations of a highly viscous glass-ionomer material over a 6-year period: a retrospective study. J Dent. 27;35: Beiruti N, Frencken JE, van't Hof MA, Taifour D, van Palenstein Helderman WH. Caries-preventive effect of a one-time application of composite resin and glass ionomer sealants after 5 years. Caries Res. 26;4: USAF Dental Evaluation & Consultation Service. Fuji IX GP Extra. Project 7-17 (2/9) 9. Lohbauer U, Krämer N, Siedschlag G, Schubert EW, Lauerer B, Müller FA, Petschelt A, Ebert J. Strength and wear resistance of a dental glass-ionomer cement with a novel nanofilled resin coating. Am J Dent. 211;24: Friedl K, Hiller KA, Friedl KH. Clinical performance of a new glass ionomer based restoration system: a retrospective cohort study. Dent Mater. 211;27: Bonifácio CC, Werner A, Kleverlaan CJ. Coating glass-ionomer cements with a nanofilled resin. Acta Odontol Scand. 211 Dec 12. [Epub ahead of print] 12. Wang L, Cefaly DF, Dos Santos JL, Dos Santos JR, Lauris JR, Mondelli RF, Atta MT. In vitro interactions between lactic acid solution and art glass-ionomer cements. J Appl Oral Sci. 29;17: Mickenautsch S, Tyas MJ, Yengopal V, Oliveira LB, Bönecker M. Absence of carious lesions at margins of glass-ionomer cement (GIC) and resin-modified GIC restorations: a systematic review. Eur J Prosthodont Restor Dent. 21;18: References >> (cont) 14. Mickenautsch S, Yengopal V. Caries-preventive effect of glass ionomer and resin-based fissure sealants on permanent teeth: An update of systematic review evidence. BMC Res Notes. 211;4: Xie D, Brantley WA, Culbertson BM, Wang G. Mechanical properties and microstructures of glassionomer cements. Dent Mater. 2;16: Ilie N, Hickel R, Valceanu AS, Huth KC. Fracture toughness of dental restorative materials. Clin Oral Investig. 212;16: Mickenautsch S, Yengopal V. Absence of carious lesions at margins of glass-ionomer cement and amalgam restorations: An update of systematic review evidence. BMC Res Notes. 211;4: Yengopal V, Mickenautsch S. Resin-modified glassionomer cements versus resin-based materials as fissure sealants: a meta-analysis of clinical trials. Eur Arch Paediatr Dent. 21;11: Mickenautsch S, Yengopal V, Banerjee A. Atraumatic restorative treatment versus amalgam restoration longevity: a systematic review. Clin Oral Investig. 21;14: Bonifácio CC, Kleverlaan CJ, Raggio DP, Werner A, de Carvalho RC, van Amerongen WE. Physical-mechanical properties of glass ionomer cements indicated for atraumatic restorative treatment. Aust Dent J. 29;54: Manufacturer s data. 22. Pereira LC, Queiroz JC, Ferreira ES, Caixeta LS, Lima AA, Barata TJ, Navarro MF, unievangelica. Influence of insertion technique on clinical performance of ART restorations. J Dent Res 21 (Spec Iss B) Abstr Manufacturer s data including product MSDS. 24. Perdigão J, Dutra-Corrêa M, Saraceni S, Ciaramicoli M, Kiyan V. Randomized Clinical Trial of Two Resin- Modified Glass Ionomer Materials: 1-year Results. Oper Dent. 212 Jul 7. [Epub ahead of print] 25. Palasuk J, Cho S, Platt J, Browning W. Nanofilled RMGI: Fracture toughness, surface roughness and gloss testing. J Dent Res 212 (Spec Iss A) Abstr Decoteau C, Ogledzki M, MacDonald S, Perry RD, Kugel G. Stain resistance of resin modified glass ionomer restoratives. J Dent Res 212 (Spec Iss A) Abstr Mitra SB, Oxman JD, Falsafi A, Ton TT. Fluoride release and recharge behavior of a nano-filled resinmodified glass ionomer compared with that of other fluoride releasing materials..am J Dent. 211;24:

8 recent developments from laboratory and clinical testing References >> (cont) 28. Versluis A, Tantbirojn D, Delong R. Does hygroscopic expansion compensate for polymerization shrinkage? J Dent Res 21 (Spec Iss A) Abstr Stoy AJ, Lien W, Vandewalle K, Speck S, Sabey K. Physical properties of newer glass-ionomer restorative materials. J Dent Res 212 (Spec Iss A) Abstr Manufacturer s data. 31. Mickenautsch S, Yengopal V. Demineralization of hard tooth tissue adjacent to resin-modified glassionomers and composite resins: a quantitative systematic review. J Oral Sci. 21;52: Burrow MF, Tyas MJ. Clinical evaluation of three adhesive systems for the restoration of non-carious cervical lesions. Oper Dent. 27;32: Xu X, Burgess JO. Compressive strength, fluoride release and recharge of fluoride-releasing materials. Biomaterials. 23;24: References >> (cont) 34. van Dijken JW. Clinical evaluation of three adhesive systems in class V non-carious lesions. Dent Mater. 2;16: Manufacturer s data. 36. Manufacturer s data. 37. Yengopal V, Mickenautsch S. Caries-preventive effect of resin-modified glass-ionomer cement (RM-GIC) versus composite resin: a quantitative systematic review. Eur Arch Paediatr Dent. 211;12: van Dijken JW, Pallesen U. Long-term dentin retention of etch-and-rinse and self-etch adhesives and a resin-modified glass ionomer cement in non-carious cervical lesions. Dent Mater. 28;24: Background note. >> Because of the changes in the range of glass-ionomer cements marketed, sources other than the refereed scientific literature have been used as reference material. This has involved using abstracts of papers and presentations at scientific meetings as well as other information from independent sources. Whilst this is not ideal, it gives a good idea of trends especially if the same general results are obtained from different research groups. Abstracts and papers of studies sponsored by manufacturers have been excluded unless otherwise indicated. Every effort has been made to make the review as complete and objective as possible. A number of products with few or no independent reports on their physical properties or clinical performance have been excluded. some practical tips... If using a light-cured restorative resin-modified GIC >> Watch limited curing depth: In the age of bulk-fill resin composites with claimed increased curing depths, keep in mind that the curing depth of currently marketed light-cured resinmodified GICs is 2 mm or slightly less. Therefore for deeper cavities, placement in 2 mm increments is required. It is for this reason if placing a Class 2 (approximo occlusal) open sandwich restoration, the use of an auto-cured, high viscosity GIC could be preferable. It can be placed in bulk and without any depth of cure problems. 2 mm Light-cured, resinmodified GICs have a limited depth of cure. Placement in 2 mm increments is required. For open sandwich restorations use of a high viscosity autocured GIC may be preferable as there are no depth-of-cure restrictions.

9 glass-ionomer cement update some practical tips on use If using a light-cured restorative resin-modified GIC >> (cont) Use like with like if adding to newly placed resinmodified GIC: Only resin-modified GIC can be added to newly placed resin-modified GIC (provided the surface has not been contaminated by blood or saliva). Auto-cured GIC, if used, will not bond. resin-modified GIC Modified technique needed if using the fingerpressure technique for placing resin-modified GIC as a pit and fissure sealant or an occlusal restoration: The finger-pressure or press-finger technique is quite straightforward when used with auto-cured glass-ionomer cements. However, if it is to be used with a light-cured, resinmodified GIC, the technique needs modification. Technique: 1. Prepare the fissure system or occlusal cavity to receive the material. 2. Apply mixed resin-modified GIC to the fissure system or inject into cavity. 3. Using a gloved finger (with the glove previously cleaned with an alcohol wipe) cover the resin-modified GIC and apply gentle pressure. 4. At the same time take the curing light and apply the light from the buccal or lingual aspect. Hold the light tip half on the finger and half on the side of the tooth. 5. Use a 4-second exposure. (Keep the light very slightly away from the finger as all modern LED and QTH units can get quite hot). There is enough transmission of light through the side of the finger and the side of the tooth to provide an initial cure of the material. 6. Remove the finger and light cure the material from the occlusal for another 4 seconds. 7. Carry out any trimming (which is usually minimal). conventional GIC resinmodified GIC Only resinmodified GIC can be added to newly placed resinmodified GIC. The GIC restoration surface must be free of contaminants such as blood or saliva. resin-modified glass-ionomer cement Insert resin-modified glassionomer cement into occlusal preparation or apply to the fissure system. gloved finger gloved finger Apply pressure with a gloved finger to compress and contour the material. Apply curing light from the buccal or lingual in the direction shown for a 4 second exposure. The transmitted light provides an initial cure of the material. Remove the gloved finger and give a further exposure to the occlusal surface.

10 some practical tips on use General tips for using glass-ionomer cements >> If using a glass-ionomer cement as a pit and fissure sealant employ a phosphoric acid-etching step: When using either an auto-cured GIC or a resin-modified GIC as a pit and fissure sealant, etching the enamel for 1-15 seconds with phosphoric acid can be a useful step. Phosphoric acid has an advantage in that it provides a reliable etch pattern on enamel. This is particularly important with teeth that have had an optimal fluoride exposure and might be resistant to the formation of an adequate micro-retentive etch pattern if a standard polyalkenoic acid cavity conditioner is used. The substitution of phosphoric acid for a polyalkenoic acid cavity conditioner has been suggested previously as a means of prolonging the retention of GIC sealants. 1 The use of this approach has been shown to enhance the retention of Vitremer (3M Espe) in a 12-month trial Yip HK, Smales RJ. Glass ionomer cements used as fissure sealants with the atraumatic restorative treatment (ART) approach:review of literature. Int Dent J 22;52: Oliveira FS, da Silva SM, Machado MA, Bijella MF, Lima JE, Abdo RC. Resin-modified glass ionomer cement and a resin-based material as occlusal sealants: a longitudinal clinical performance. J Dent Child (Chic). 28;75: % phosphoric acid The application of 35-37% phosphoric acid can be used to obtain a micromechanical etch pattern at the entrance to a fissure and aid in sealant retention. When restoring a Class 2 cavity with an open sandwich restoration keep the glass-ionomer cement in tha approximal box apical to the contact area: A potential weak point of approximo-occlusal (Class 2) open sandwich restorations is the presence of glass-ionomer cement at the contact area. A long-term study (6 years) found that Class 2 Fuji IX (GC) restorations performed very well except at the contact area. Approximately 6% of the restorations showed some dissolution of material at this site. 1 Therefore when using GIC in an approximal box in the open sandwich technique it is important to keep the material well below the contact area. Doing so minimises the possibility of any localised dissolution of the material in this area. 1. Scholtanus JD, Huysmans MC. Clinical failure of class-ii restorations of a highly viscous glass-ionomer material over a 6-year period: a retrospective study. J Dent. 27;35: composite GIC contact area finish GIC here When using a GIC in the open sandwich technique it is advisable to keep the material well below the contact area as shown. Finishing the GIC at or above the contact area can predispose it to localised dissolution in this location. Use a curing light with auto-cured GIC if accelerated setting and early hardness are required. Situations arise when using auto-cured GICs when it is desirable to speed up the setting reaction. It has been found that by heating an auto-cured GIC immediately after placement, not only is the setting time accelerated but some initial physical properties are improved also. One study found that heat (up to 7 C) not only accelerated the setting reaction but improved such properties as the compressive strength of GIC materials including Fuji IX Fast (GC) and (3M Espe). 1 > heat from curing light curing light auto-cured GIC

11 glass-ionomer cement update some practical tips on use General tips for using glass-ionomer cements >> (cont) Use a curing light with auto-cured GIC if accelerated setting and early hardness are required. (cont) Whilst it is not easy in the mouth to achieve the temperature levels used in this study, modern curing lights emit sufficient heat to accelerate the setting process. The process has also been found to increase the early hardness of an auto-cured GIC Kleverlaan CJ, van Duinen RN, Feilzer AJ. Mechanical properties of glass ionomer cements affected by curing methods. Dent Mater 24;2: O'Brien T, Shoja-Assadi F, Lea SC, Burke FJ, Palin WM. Extrinsic energy sources affect hardness through depth during set of a glass-ionomer cement. J Dent. 21;38: tweezers tightly-rolled pellet of cotton wool (lightly moistened) glassionomer cement Additional pressure may be required when placing a highviscosity GIC. From time to time an operator may not be completely satisfied that a high-viscosity glass-ionomer cement (GIC) has been packed sufficiently into a prepared space. For example, this may occur when placing a GIC into an approximal box or when filling a preparation for a tunnel restoration. To obtain an optimal seal there has to be a close adaptation between the material and the cavity walls. The following is an earlier technique that has proved useful and is recommended by some manufacturers. Technique: 1. Inject the high-viscosity GIC into the prepared cavity. 2. Tamp into place using the preferred packing instrument. 3. Take a tightly-rolled pellet of cotton wool in a pair of tweezers and slightly moisten the cotton wool with water. Remove any excess on the end of a cotton roll. (The minuscule amount of moisture in the cotton pellet should have negligible effect on glass-ionomer cement). 4. Whilst the GIC is still workable, use the cotton wool to force the material into the tight space. Tip: Tightly rolled means tightly rolled. The strands in a standard cotton pellet are far too loose. A lightly moistened, tightly-rolled pellet of cotton wool can be used to force an increment of glassionomer cement into place and secure good adaptation. Left: The use of a lightly moistened, tightly-rolled pellet of cotton wool is also a useful technique in the restoration of a tunnel preparation with GIC. Low viscosity GICs for pit and fissure sealing on newly erupting permanent molars. A new 2-year study has confirmed the value of using a low-viscosity auto-cured GIC on newly erupting permanent molar teeth. When compared to a resin-based sealant, the GIC (Fuji VII (white) - GC) had a slightly higher retention rate. However, importantly, in some cases where sealants were lost, demineralisation was seen when the resin sealant had been used. This did not occur when the GIC sealant had been employed. Reference: Antonson SA et al., J Am Dent Assoc. 212;143: