During our senior year we can opt to have a concentration in various disciplines (ie, prosthodontics, pediatric dentistry, omfs, esthetica, etc). Each concentration requires some extra coursework, so in that sense we can take electives. I haven't heard of anyone taking any undergraduate or graduate coursework in addition to the DDS courses with the exception of MBA or MPH dual degree students - but in those cases they are typically paying more for those degrees and tacking on an extra year to the DDS.