Amalgam phase-out: what next for dentistry? Costs and benefits of the alternative direct restorations

Abstract

Introduction Dental amalgam has been used to restore posterior teeth for centuries. It contains mercury and concerns around its toxicity have mandated a phase-down of its use and an exploration of the feasibility of its phase-out in England by 2030. This thesis explored the current use of amalgam and the relative costs and benefits of the directly placed alternatives in the English NHS primary care setting. Methods This thesis comprised three complimentary phases. Phase one quantified the use of materials and techniques to restore posterior teeth by UK primary care clinicians, alongside their opinions of the phase-down using an online questionnaire. Phase two quantified UK public preferences for different aspects of posterior restorations in terms of differences in their willingness to pay using a discrete choice experiment. Phase three was an economic evaluation of amalgam versus the alternative restorations in the English NHS setting. A model of restoration and reintervention was built to compare the lifetime costs and outcomes of amalgam with the alternatives. Data from all phases were then used in a cost-consequence analysis which quantified the differences in various outcomes and costs from the perspective of funders, patients and clinicians. Results Amalgam is frequently used in NHS primary care and clinician confidence in the alternatives is limited, with significantly higher reported post-operative complications. The lifetime monetary and time costs to patients, funders and clinicians are significantly higher for composite than amalgam and clinical outcomes are significantly worse. In terms of preferences, the UK public value amalgam more than composite, with the largest relative difference seen in low-income groups. Discussion An imminent phase-out of amalgam in England would lead to concerns around survival of restored teeth, funding, patient safety and access to care, which risk exacerbating existing health inequalities.