In an effort to appraise the current clinical evidence regarding the merits of glass ionomers as tooth restorations and sealants, the SYSTEM Initiative of the Faculty of Health Sciences at the University of the Witwatersrand in Johannesburg, South Africa, has conducted a number of systematic reviews of clinical trials. The SYSTEM Initiative has investigated the accuracy of comparison results from longitudinal studies with those from randomized control trials (RCT).
The SYSTEM Initiative’s results show that no clinical evidence exists to substantiate the belief that high-viscosity glass ionomers are inferior to the current gold standard when placing restorations in posterior load-bearing teeth and when sealing pit and fissure to prevent the development of tooth caries.
All longitudinal studies of high-viscosity glass ionomer restorations were compared with studies of amalgam restorations placed in posterior load-bearing teeth. All studies reviewed were published in the last ten years. Overall, a largely higher performance for amalgam was found. However, no difference between high-viscosity glass ionomer and silver amalgam was found in any of the RCTs published during the same time period.
A similar systematic review of available literature in 2008 also indicated a deficiency in clinical evidence to support the idea that resin-based fissure sealants protect better against tooth caries than glass-ionomer-based sealants. A subsequent investigation was conducted in 2013 and established that the conclusion of the original systematic review remains current.
The published full reports of the findings are available online:
[1] Mickenautsch S, Yengopal V. Failure rate of high-viscosity GIC based ART compared to that of conventional amalgam restorations - evidence from a systematic review update. S Afr Dent J 2012; 67: 329-31.
http://www.ncbi.nlm.nih.gov/pubmed/23951787
[2] Mickenautsch S, Yengopal V. Direct contra naïve-indirect comparison of clinical failure rates between high-viscosity GIC and conventional amalgam restorations. An empirical study. PLOS One 2013; 8: e78397.
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0078397
[3] 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 2011; 4: 22.
http://www.biomedcentral.com/1756-0500/4/22
[4] Mickenautsch S, Yengopal V. The modified Ottawa method to establish the update need of a systematic review: Glass-ionomer versus resin sealants for caries prevention. J Appl Oral Sci 2013; 21: 482-9.
