Objectives: This study was performed to examine the cultivable flora in dentine after manual excavation of caries lesions using the Atraumatic Restorative Treatment (ART) technique and to examine for associations between the microbiological results and cavity size, dentine colour and consistency.
Methods: Dentine samples from 40 caries lesions were collected before and after treatment and cultured for total viable counts (TVC), mutans streptococci (MS) and lactobacilli.
Results: The bacterial bioburden between the two samples showed a significant reduction in the frequency and proportions of TVC and MS but not lactobacilli.
Conclusion: Cavity preparation produced a clinical change in dentine colour and consistency from dark shades and soft dentine at enamel dentine junction to light shades and hard dentine at the cavity floor. The results show that cavity size, dentine colour and consistency are not absolute indicators of the microbiological bioburden in an ART cavity.