“…* References: 18,19,20,21,22,36,53 ; ** References: 17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45 . to the main argument pointed out previously in the literature 10 . Klinge & Norlund 10 suggest that the statistically significant and negative association between socioeconomic conditions and periodontal disease is questionable, because the studies that come to this conclusion have been, in their majority, cross-sectional and most did not adjust this association for smoking in their analysis.…”