JOHANNESBURG, July 18, 2014 /PRNewswire/ -- 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, University of the Witwatersrand, Johannesburg, has conducted a number of systematic reviews of clinical trials while simultaneously investigating the accuracy of comparison results from longitudinal studies with that from randomised control trials (RCT).
SYSTEM'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.
When all longitudinal studies, published during the last ten years, for high-viscosity glass-ionomer restorations were compared with that of amalgam restorations placed in posterior load bearing teeth a largely higher performance for amalgam was found. However, no difference between high-viscosity glass-ionomer and silver amalgam was found in all RCTs, published during the same time period.
A similar systematic review of available literature 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 to the original systematic review in 2008 was conducted in 2013 and established that its conclusion remains current.
The published full reports of the findings are available online:
 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
 Mickenautsch S, Yengopal V. Direct contra naive-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
 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
 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. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3881834/