Abstract
Abstract: The objectives are to investigate the association between dental caries and H.pylori, the association between dental caries and smoking among Saudi students, and to investigate the association between smoking and H.pylori among students with dental caries. The present cross sectional study included 120 male students from Aljouf University. Participating students were clinically examined for dental caries. Urine samples were tested for cotinine and stool samples were tested for H.pylori. Both cotinine and H.pylori was tested using strips especially prepared based on antigen-antibody reaction (COT, Innovacon Inc., USA, Helicobacter antigen Quick, GA Inc, Germany). Statistical analysis was done using Chi-Square test. The mean age of study participants was 22.37+-1.50 years. The mean of teeth with caries was 9.57+-4.68. There were 93 (77.5%) students positive for H.pylori, and 100 (83.3%) positive for cotinine. There was a significant relationship between cotinine and caries (P=0.000), and H.pylori and dental caries (P=0.000). The co-existence of H.pylori and cotinine was also significant among cases with caries (P=0.000). The present study showed that cotinine and H.pylori were significantly associated with dental caries. The co-existence of both among cases with dental caries may be a new finding and may work synergistically with each other.