Confounding and interaction effect of Treponema denticola salivary carriage in chronic periodontitis.
OBJECTIVE
To evaluate the salivary carriage of Treponema denticola and its association with demographic variables in the etiopathogenesis of chronic periodontitis.


METHODS
Ninety-seven chronic periodontitis (CP) patients and a control group of 51 healthy subjects (HC) were selected. Periodontal status was assessed by criteria based on probing depth, attachment loss, extent, and severity of periodontal breakdown. A polymerase chain reaction method was used to determine the occurrence of T. denticola in saliva samples. Risk indicators for CP were assessed individually and adjusted for confounding and/or interaction using a logistic regression model.


RESULTS
Although univariate analysis revealed a positive association of age >or=30 years, smoking, and salivary carriage of T. denticola with CP, after logistic regression analysis, the association between age >or=30 years/smoking and CP persisted, whereas salivary carriage of T. denticola failed to achieve statistical significance. An interaction effect was significantly detected between these three variables.


CONCLUSIONS
Although salivary carriage of T. denticola may be a risk indicator for CP, its pathogenicity should not be exclusively endorsed to its detection in saliva, but it might be associated with the synergistic biological interaction of the bacterium with some demographic characteristics of the susceptible host.
POPCAD Research Group, Laboratory of Immunodetection and Bioanalysis, Faculty of Dentistry, University of Antioquia, Medellín, Colombia.
M C
MC
Martínez-Pabón
A
A
Martínez-Gaviria
D M
DM
Isaza-Guzmán
C E
CE
Muskus-López
S I
SI
Tobón-Arroyave
D000328:Adult; D000367:Age Factors; D000368:Aged; D000704:Analysis of Variance; D002353:Carrier State / Q000382:microbiology*; D016022:Case-Control Studies; D055113:Chronic Periodontitis / Q000382:microbiology*; D015986:Confounding Factors, Epidemiologic; D003430:Cross-Sectional Studies; D004269:DNA, Bacterial / Q000032:analysis; D004198:Disease Susceptibility; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012307:Risk Factors; D012463:Saliva / Q000382:microbiology*; D012737:Sex Factors; D012907:Smoking; D018709:Statistics, Nonparametric; D048373:Treponema denticola / Q000302:isolation & purification / Q000472:pathogenicity*; D055815:Young Adult
D004269:DNA, Bacterial