Limitations
autism
This study has some limitations; however, implementing lessons learned from our pilot study enabled us to successfully avoid many in the execution of this study. First, despite our efforts to minimize the burden to study participation, our attrition rate was greater than anticipated, with 162 participants completing 1 dental cleaning and 138 participants completing 2, from the original 220 participants enrolled. Study features minimizing the potential effect of missing data included that participants with one dental cleaning were demographically similar to those with 2, any unmeasured participant characteristic associated with missing a dental visit would have been equally likely to have been randomized to SADE first as to RDE first, and use of statistical methods where data are missing completely at random is not required. Second, because our consecutive sampling strategy, our sex distribution reflects more closely the autism distribution reported in the community (1 girl to 4 boys). Future research should examine possible sex-specific differences for SADE, since there are documented health-related sex differences in the autistic population.