Thedentalresearchliteratureconta Secondaryresearchincludesguideli,economicanddecisionanalysesandbo nonsystematicandsystematicreview(appraisalofsystematicreviewsisdi).Descriptivestudies(e ﹒ g . casereports,caseseriesofcrosssectionalsur‐veys)tendtobehypothe ......