The objective of this study aimed to assess the caries-preventive potential of various CW CO2 laser parameters, and to explore the effect of the laser power density on the caries inhibition activity.Extracted human deciduous molars were irradiated with three various power densities, by changing the output power, the exposure time, and the spot diameter. The CO2 laser system emitted laser with 10.6μm in wavelength. All teeth were subjected to carieslike lesion formation by 3.5 pH lactic acid for 21 days. The teeth after that were sectioned into ground cross sections and the lesion depths were measured under a polarizing microscope.CW CO2 laser preventive treatments inhibited carieslike lesion progression up to 82%. This effect was improved with increasing power density within the limits of the examined laser parameters.


The aim of this study was to assess the incidence of two root canals in the mesial root of the extracted permanent maxillary first molars of a Sulaimani population. An ex vivo study on 180 extracted permanent maxillary first molars was conducted. The teeth were examined clinically and radiographically. The results showed that 23.3 % of the examined teeth had two canals in the mesial root (17.0 % with one apical foramen and 6.3 % with two separate foramens).