INTRODUCTIONAlthough it is well known that treatment with fixed appliances increases the risk of enamel demineralization, little information is available about preventive measures that orthodontists actually use. This study was executed to survey measures used in orthodontic practices to prevent decalcifications during fixed appliance treatment, and to compare these measures with the available evidence-based information.METHODSA questionnaire was sent to all privately practicing orthodontists in the Netherlands who were affiliated with the Dutch Dental Association.RESULTSOf 229 orthodontists, 178 (78%) returned the questionnaires. Most of the orthodontists had a basic practice protocol for preventing demineralizations at the start of treatment. This protocol nearly always included oral hygiene instructions. If demineralizations occurred, 99% of the orthodontists took extra measures. Comparing the measures applied in the orthodontic practices with the evidence from a systematic review, a number of differences became apparent. The additional use of chlorhexidine or toothpaste with a high fluoride concentration (which has been demonstrated to have an inhibitive effect) is rarely prescribed. Fluoride rinse is prescribed most often, although there is not any high-quality, long-term study that demonstrates a caries preventive effect in orthodontic patients. Sixty-eight percent of the orthodontists considered it necessary to develop a practice guideline for preventing demineralizations.CONCLUSIONSOrthodontists do not implement the available evidence in order to prevent enamel demineralizations during fixed-appliance treatment. A practice guideline incorporating this information should be developed.