Assessing the correlation between salivary parameters and caries incidence

Objectives: The null hypothesis investigated was that there are no correlations between intra-oral carious lesions and various salivary parameters, tested using the Saliva check kit (GC Corp). Method: With ethical approval, 50 subjects, with at least 16 teeth and not having eaten for 2 hours prior to the investigations, underwent clinical and radiographic examinations. Occlusal and smooth surface lesions were separately recorded using a modified visual index described by ICDAS (International Caries Detection and Assessment System). Scores ranged from 1 to 6 depending on clinical severity and depth of the lesion. Scores 1 / 2 were grouped descriptively as mild, essentially enamel lesions. Scores 3 / 4 were moderate lesions, essentially in the outer and middle thirds of dentine with possible cavitation and scores 5 / 6 were severe lesions with cavitation and possible pulpal involvement. Salivary parameters tested included hydration, resting pH, stimulated flow and stimulated buffering scores. Spearman's Rank correlation was used to analyse data. Results: Hydration, resting pH and stimulated flow did not correlate significantly with caries scores. A high buffering score correlated positively with the number of smooth surface lesions detected (p=0.0079, r=0.3714). Mild and moderate caries scores correlated and approached clinical significance with buffering (p=0.0760, r=0.2532) and (p= 0.0547, r= -0.2735) respectively. There were no correlations with any salivary parameters tested and the presence of severe lesions. Conclusion: saliva buffering scores were correlated to the presence of smooth surface lesions.