Objectives: To assess the effectiveness and cost-effectiveness of HealOzone (CurOzone USA Inc., Ontario, Canada) for the management of pit and fissure caries, and root caries. The complete HealOzone procedure involves the direct application of ozone gas to the caries lesion on the tooth surface, the use of a remineralising solution immediately after application of ozone and the supply of a 'patient kit', which consists of toothpaste, oral rinse and oral spray all containing fluoride.
Data sources: Electronic databases up to May 2004 (except Conference Papers Index, which were searched up to May 2002).
Review methods: A systematic review of the effectiveness of HealOzone for the management of tooth decay was carried out. A systematic review of existing economic evaluations of ozone for dental caries was also planned but no suitable studies were identified. The economic evaluation included in the industry submission was critically appraised and summarised. A Markov model was constructed to explore possible cost-effectiveness aspects of HealOzone in addition to current management of dental caries.
Results: Five full-text reports and five studies published as abstracts met the inclusion criteria. The five full-text reports consisted of two randomised controlled trials (RCTs) assessing the use of HealOzone for the management of primary root caries and two doctoral theses of three unpublished randomised trials assessing the use of HealOzone for the management of occlusal caries. Of the abstracts, four assessed the effects of HealOzone for the management of occlusal caries and one the effects of HealOzone for the management of root caries. Overall, the quality of the studies was modest, with many important methodological aspects not reported (e.g. concealment of allocation, blinding procedures, compliance of patients with home treatment). In particular, there were some concerns about the choice of statistical analyses. In most of the full-text studies analyses were undertaken at lesion level, ignoring the clustering of lesions within patients. The nature of the methodological concerns was sufficient to raise doubts about the validity of the included studies' findings. A quantitative synthesis of results was deemed inappropriate. On the whole, there is not enough evidence from published RCTs on which to judge the effectiveness of ozone for the management of both occlusal and root caries. The perspective adopted for the study was that of the NHS and Personal Social Services. The analysis, carried out over a 5-year period, indicated that treatment using current management plus HealOzone cost more than current management alone for non-cavitated pit and fissure caries (40.49 pounds versus 24.78 pounds), but cost less for non-cavitated root caries ( 14.63 pounds versus 21.45 pounds). Given the limitations of the calculations these figures should be regarded as illustrative, not definitive. It was not possible to measure health benefits in terms of quality-adjusted life-years, due to uncertainties around the evidence of clinical effectiveness, and to the fact that the adverse events avoided are transient (e.g. pain from injection of local anaesthetic, fear of the drill). One-way sensitivity analysis was applied to the model. However, owing to the limitations of the economic analysis, this should be regarded as merely speculative. For non-cavitated pit and fissure caries, the HealOzone option was always more expensive than current management when the probability of cure using the HealOzone option was 70% or lower. For non-cavitated root caries the costs of the HealOzone comparator were lower than those of current management only when cure rates from HealOzone were at least 80%. The costs of current management were higher than those of the HealOzone option when the cure rate for current management was 40% or lower. One-way sensitivity analysis was also performed using similar NHS Statement of Dental Remuneration codes to those that are used in the industry submission. This did not alter the results for non-cavitated pit fissure caries as the discounted net present value of current management remained lower than that of the HealOzone comparator ( 22.65 pounds versus 33.39 pounds).
Conclusions: Any treatment that preserves teeth and avoids fillings is welcome. However, the current evidence base for HealOzone is insufficient to conclude that it is a cost-effective addition to the management and treatment of occlusal and root caries. To make a decision on whether HealOzone is a cost-effective alternative to current preventive methods for the management of dental caries, further research into its clinical effectiveness is required. Independent RCTs of the effectiveness and cost-effectiveness of HealOzone for the management of occlusal caries and root caries need to be properly conducted with adequate design, outcome measures and methods for statistical analyses.