There are many patients in general practice with health complaints that cannot be medically explained. Some of these patients attribute their problems to dental amalgam.
This study examined the cost-effectiveness of the removal of amalgam fillings in patients with medically unexplained physical symptoms (MUPS) attributed to amalgam compared to usual care, based on a prospective cohort study in Norway.
Costs were determined using a micro-costing approach at the individual level. Health outcomes were documented at baseline and approximately two years later for both the intervention and the usual care using EQ-5D-5L. Quality-adjusted life year (QALY) was used as the main outcome measure. A decision analytical model was developed to estimate the incremental cost-effectiveness of the intervention. Both probabilistic and one-way sensitivity analyses were conducted to assess the impact of uncertainty on costs and effectiveness.
In patients who attributed health complaints to dental amalgam and fulfilled the inclusion and exclusion criteria, amalgam removal was associated with a modest increase in costs at the societal level as well as improved health outcomes. In the base-case analysis, the mean incremental cost per patient in the amalgam group was NOK 19 416 compared to the MUPS group, while the mean incremental QALY was 0.119 with a time horizon of two years. Thus, the incremental costs per QALY of the intervention were NOK 162 680, which is usually considered to be cost-effective in Norway. The estimated incremental cost per QALY decreased with increasing time horizons, and amalgam removal was found to be cost-saving over both 5 and 10 years.
The authors concluded that this study provides insight into the costs and health outcomes associated with the removal of amalgam restorations in patients who attribute health complaints to dental amalgam fillings, which are appropriate instruments to inform health care priorities.
The group sizes were 32 and 28 respectively. This study was thus almost laughably small and therefore cannot lead to firm conclusions of any type. In this contest, a recent systematic review might be relevant; it concluded as follows:
On the basis of the available RCTs, amalgam restorations, if compared with resin-based fillings, do not show an increased risk for systemic diseases. There is still insufficient evidence to exclude or demonstrate any direct influence on general health. The removal of old amalgam restorations and their substitution with more modern adhesive restorations should be performed only when clinically necessary and not just for material concerns. In order to better evaluate the safety of dental amalgam compared to other more modern restorative materials, further RCTs that consider important parameters such as long and uniform follow up periods, number of restorations per patient, and sample populations representative of chronic or degenerative diseases are needed.
Similarly, a review of the evidence might be informative:
Since more than 100 years amalgam is successfully used for the functional restoration of decayed teeth. During the early 1990s the use of amalgam has been discredited by a not very objective discussion about small amounts of quicksilver that can evaporate from the material. Recent studies and reviews, however, found little to no correlation between systemic or local diseases and amalgam restorations in man. Allergic reactions are extremely rare. Most quicksilver evaporates during placement and removal of amalgam restorations. Hence it is not recommended to make extensive rehabilitations with amalgam in pregnant or nursing women. To date, there is no dental material, which can fully substitute amalgam as a restorative material. According to present scientific evidence the use of amalgam is not a health hazard.
Furthermore, there is evidence that the removal of amalgam fillings is not such a good idea. One study, for instance, showed that the mercury released by the physical action of the drill, the replacement material and especially the final destination of the amalgam waste can increase contamination levels that can be a risk for human and environment health.
As dental amalgam removal does not seem risk-free, it is perhaps unwise to remove these fillings at all. Patients who are convinced that their amalgam fillings make them ill might simply benefit from assurance. After all, we also do not re-lay electric cables because some people feel they are the cause of their ill-health.