The psychological benefits of dental implants in patients distressed by untolerated dentures

It has been claimed that permanent dental implants improve the well-being o f patients distressed by their removable dentures. Research appears to sugg est that this improvement is temporary but the findings have been obscured by the use of inappropriate measures of distress, failure to control for Ty pe II and tin ubiquitous use of repeated pair-wise testing) Type I statisti cal error, poor measures of dental functioning, inadequate descriptions of sampling, failure to include moderating variables such as the impact of den tures on daily living and failure to allow for causal effects of distress. Individual variation has been overlooked: only some patients may be signifi cantly distressed by their dentures. It has been difficult to find control groups of patients to exclude the effect of confounding influences. The cru cial assumption, that psychological distress reduces as dental functioning improves, has not been examined. Statistical modelling, using suitable meas ures of chronic distress, controlling for the effects of moderating variabl es and examining causal relationships, would help to clarify this, Psycholo gical distress, according to statistical analysis designed to avoid Type I and Type II error, should be less, long after the fitting of implants than before.