Aim: 

Salivary thiobarbituric acid reacting substances (TBARS) have been proved as a potential marker of intraoral oxidative stress and parodontal status. This study was aimed at the analysis of intra- and interindividual variability of TBARS in saliva.

Methods: 

Twenty two young healthy volunteers (12F & 10M) collected saliva samples daily in the morning during a period of 30 consecutive days. Salivary TBARS were measured spectrophotometrically. Time series analysis was done using standard statistical methods.

Results: 

Repeated measures ANOVA showed significant between day variations of salivary MDA (p < 0.001). The dynamics did not differ between genders, however, the data was not synchronized, and thus, gender differences in endogenous dynamics cannot be ruled out. Intraindividual variability was very high in both genders with coefficients of variation of more than 70%. Interindividual variability was higher in men than in women (63% vs. 20%; p < 0.001).

Discussion: 

The relatively high intraindividual variability indicates that repeated samplings and subsequent measurements are needed for individual diagnostics. Gender differences and interindividual variability will be taken into account in running clinical studies on patients with periodontal and dental diseases. Factors influencing the variability of salivary TBARS including infradian biorhythms should be uncovered by further studies.