Systematic Review Evidence Shows Silver Amalgam Not Superior To High-Viscosity Glass Ionomers for Posterior Tooth Restorations

For several decades many practicing dentists have accepted the consensus that silver amalgam is clinically superior to glass-ionomers when placing restorations in posterior teeth despite a distinct lack in valid clinical evidence to support this belief. In an effort to appraise the current clinical evidence, the SYSTEM Initiative of the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, has conducted a systematic review of randomised control trials and a meta-epidemiological study to this topic. This scientifically focused analysis incorporated a systematic literature search in 17 global and regional databases, databases for open access journals and ‘grey’ literature. In addition to searching the global databases PubMed/Medline and the Cochrane library, SYSTEM searched additional regional English databases comprised of the scientific dental literature from Africa, Europe, India and North America, whilst regional non-English databases comprised of the dental literature from China and Latin-speaking American countries. In total, 38 controlled clinical trials were accepted as evidence, comprising the investigation of more than 10 000 placed tooth restorations. The outcome shows that amalgam cannot be regarded as superior to new generation, high viscous glass-ionomers fillings, due to a lack of clinically meaningful differences in both restoration types’ failure rates beyond the play of chance. The results of SYSTEM’s meta-epidemiological study shows that statements concerning amalgam’s superiority are based on incorrect statistical comparison methods. Such methods continue to include and rely on the common naïve-indirect comparison of restoration failure rates from uncontrolled clinical longitudinal studies. Simply put, the traditional argument against the use […]

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