Properties of Glass-Ionomer Cements Sealed with Petroleum Jelly or Wax

A study has been carried out to determine the effect of coating two commercial glass-ionomer cements in either petroleum jelly or wax. After coating, specimens were stored in water for 24 or 168 hours, then the coating removed and the surface examined. Coating in wax was found to increase the surface hardness significantly compared with the uncoated control, whereas coating the specimens in petroleum jelly led to only a slight increase in surface hardness. Coating in wax led to no detectable ion release after either 24 or 168 hours, though there was some ion release after the coating had been removed and the specimens exposed to water for a further 24 hours. This shows that soluble species remained in these specimens. Overall, this study confirms the idea that immature glass-ionomers should be protected from early exposure to moisture, and that the protection offered by petroleum jelly is only modest.




References:
[1] Wilson AD, Kent BE. The glass-ionomer cement: A new translucent
dental filling material. J Appl Chem Biotechnol 1971; 21:313.
[2] Kent BE, Wilson AD. The properties of a glass-ionomer cement. Br
Dent J 1973; 135:322-6.
[3] Mount GJ. A colour atlas of glass-ionomer cements. 3rd edn. London.
Martin Dunitz. 2002.
[4] Causton B. The physico-chemical consequences of exposing glass
ionomer cements to water during setting. Biomaterials 1981; 2:112-5.
[5] Sidhu SK, Sherriff M, Watson TF. The effects of maturity and
dehydration shrinkage on a resin-modified glass-ionomer restoration. J
Dent Res 1997; 76:1495-1501.
[6] Brito CR, Velasco LG, Bonini GAVC, Imparato JCP, Raggio DP. Glassionomer
cement hardness after different materials for surface protection.
J Biomed Mater Res 2010; 93:243-6.
[7] Earl MSA, Mount GJ, Hume WR. The effect of varnishes and other
surface treatments on water movement across the glass-ionomer cement
surface. Aust Dent J 1989; 39:326-9.
[8] Frencken JE, Wolke J. Clinical and SEM assessment of ART high
viscosity glass-ionomer sealants after 8-13 years in 4 teeth. J Dent 2010;
38:59-64.
[9] Forsten L. Fluoride release from a glass ionomer cement. Eur J Oral Sci
1977:85:503-4.
[10] McKnight-Hanes C, Whitford GM. Fluoride release from three glass
ionomer materials and the effect of varnishing with or without finishing.
Caries Res 1992; 26:345-50.
[11] Nicholson JW, Czarnecka B. Kinetic studies of the effect of varnish on
water loss by glass-ionomer cements. Dent Mater 2007; 23:1549-52.
[12] Nicholson JW, Czarnecka B. The kinetics of water uptake and loss in
glass-ionomer cements. J Mater Sci Mater Med 2008; 19:1723-7.
[13] Schmage P, Nergiz I, Platzer U, Roseutritt M. Wear and hardness of
different core build-up materials. J Biomed Mater Res B: Appl Biomater
2009; 91:71-9.
[14] Silva RC, Zuanon ACC, Esberard RR, Candido MSM, Machado JS. In
vitro microhardness of glass ionomer cements. J Mater Sci: Mater Med
2007;18:139-142
[15] Phillips S, Bishop BM. An in vitro study of the effect of moisture on
glass-ionomer cement. Quintessence Int 1985; 2:175-177.
[16] Gladys S, Van Meerbeck B, Braen M, Lambrechts P, VanherleG.
Comparative physio-mechanical characterisation of new hybrid
restorative materials with conventional glass-ionomer and resin
composite restorative materials. J Dent Res 1997; 76:883-894.