Glass-ionomers are commonly regarded as inferior to amalgam or composite resin when used for placing tooth restorations. However, our research over the last years could establish:
General emerging evidence: The requirements for an ideal restorative material include adhesion to tooth structure (enamel and dentine) and an ability to withstand the traumas of occlusion. However, some level of an anticaries effect is also desirable. After a long history of glass-ionomer cement (GIC) development, an evidence base in support of the therapeutic effect of GIC, particularly with regard to its anticaries effect, is emerging. This evidence is increasingly presented through systematic reviews of clinical GIC application and, to a certain extent, relates to a caries-preventive effect of the material itself [1].
Glass-ionomers & carious lesion development: Significantly less carious lesions were observed on single-surface GIC restorations in permanent teeth after 6 years as compared to restorations with amalgam (OR 2.64 - CI 95% 1.39 - 5.03, p= 0.003). Studies investigating carious lesions at margins of restorations in primary teeth showed no difference between both materials after 3 and 8 years. Carious lesions at margins of single-surface GIC restorations are less common than with amalgam fillings after 6 years in permanent teeth. No difference was observed in primary teeth [2]. In addition, the database search (up to 10 August 2010) identified 1 new trial, in addition to the 9 included in the original systematic review, and 11 further trials were included after a hand-search and reference check. The overall results of the computed datasets suggest that GIC has a higher caries-preventive effect than amalgam for restorations in permanent teeth. No difference was found for restorations in the primary dentition. This outcome is in agreement with the conclusions of the original systematic review [3].
Glass-ionomers versus composite resins: The available evidence suggests no difference in the failure rates between composite resin and glass-ionomer restorations beyond the play of chance [4].
Glass-ionomers versus amalgam: Controlled clinical trials with high-viscosity glass-ionomer cements (HVGIC) restorations placed using Atraumatic Restorative Treatment (ART) provide the bulk of the available evidence that suggest that the failure rate of direct posterior HVGIC restorations in permanent teeth are comparable to that of dental amalgam restorations [5]. The majority of the results show no differences between the types of intervention. The current evidence indicates that the failure rate of HVGIC restorations is not higher than, but is similar to that of conventional amalgam fillings after periods longer than six years [6]. The prior Odds that HVGICs are clinically inferior to amalgam as restorative materials in posterior permanent teeth in relation to the hypothesis that this is not so was 1.12 to 1. The Likelihood Ratio based on new evidence in favour the hypothesis was zero and the subsequent posterior Odds 0 to 1. Therefore, based on the new evidence, the Odds that HVGICs are clinically inferior to amalgam as restorative materials in posterior permanent teeth degreased from 1.12 to zero. The current evidence suggests lack of support for the hypothesis that high-viscosity glass-ionomer cements are inferior to silver amalgam as restorative materials for permanent posterior teeth [7].
References
[1] Mickenautsch S, Mount G, Yengopal V. Therapeutic effect of glass-ionomers: an overview of evidence. Aust Dent J. 2011;56(1):10-103. Abstract
[2] Mickenautsch S, Yengopal V, Leal SC, Oliveira LB, Bezerra AC, Bönecker M. Absence of carious lesions at margins of glass-ionomer and amalgam restorations: a meta- analysis. Eur J Paediatr Dent. 2009;10(1):41-46.Abstract
[3] 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. 2011;4:58. Abstract
[4] Mickenautsch S, Yengopal V. Failure Rate of Direct High-Viscosity Glass-Ionomer Versus Hybrid Resin Composite Restorations in Posterior Permanent Teeth - a Systematic Review. Open Dent J. 2015;9:438-448. Abstract
[5] Mickenautsch S. High-viscosity glass-ionomer cements for direct posterior tooth restorations in permanent teeth: The evidence in brief. J Dent. 2016;55:121-123. Abstract
[6] Mickenautsch S, Yengopal V. Failure rate of high-viscosity GIC based ART compared with that of conventional amalgam restorations--evidence from an update of a systematic review. SADJ. 2012;67(7):329-331. Abstract
[7] Mickenautsch S. Are high-viscosity glass-ionomer cements inferior to silver amalgam as restorative materials for permanent posterior teeth? A Bayesian analysis. BMC Oral Health. 2015;15(1):118. Abstract
