The objective of this study aimed to assess the caries-preventive potential of various chopped CO2 laser parameters, and to explore the effect of the laser energy density on the caries inhibition activity.Roots of extracted human premolar teeth were irradiated with three various energy densities (25.47, 50.93, and 101.86) J/cm2, by changing the number of pulses, the pulse duration, and the spot diameter. The CO2 laser system emitted laser with 10.6m in wavelength. All roots were subjected to carieslike lesion formation by 3.5 pH lactic acid for 21 days. The roots after that were sectioned into ground cross sections and the lesion depths were measured under a polarizing microscope.Chopped CO2 laser preventive treatments inhibited carieslike lesion progression up to 36%. This effect was improved with decreased total energy density within the limits of the examined laser parameters.

The objective of this study aimed to assess the carieslike lesion preventive potential of low power dye assisted He-Ne laser.Enamel of extracted human premolar teeth were painted with methylene blue dye and irradiated with 5 mW of He-Ne laser, which emitted laser with 632.8 nm in wavelength. Another group were irradiated without dye application, and the third group was served as control (without laser irradiation). All samples were subjected to carieslike lesion formation by 3.5 pH lactic acid for 21 days. The crowns after that were sectioned into ground cross sections and the lesion depths were measured under a polarizing microscope.According to this study, successful carieslike lesion inhibition could be achieved to 29% extent, by using low power dye assisted He-Ne laser irradiation.

In this study anterior filling was used type of G-aenial and used in the restoration of teeth, then conducted a study and divided into four groups of the first sample, which is the group A, which was irradiated by laser and then hardened by Light Curing then irradiated with laser and the third sample C, which was irradiated with Light Curing, and the laser on the sample at the same time and the fourth sample D The original samples are not exposed to irradiation (control) Based on the filling specifications The sample was prepared cylindrical and dimensions (10 × 6mm) to be used in a number of Synthetic measurements such as x-ray diffraction analysis, electron microscopy scanner and some important mechanical properties such as hardness and wear. The results showed X-ray diffraction that the components of A, B, C and D aggregates gave emitted precipitation and a thin crystalline state clear all forms of x-ray diffraction. It was found that the XRD test of the B group showed a significant increase in the intensity of the material in the G-aenial filler and is indicated by the laser effect clearly after light therapy and laser irradiation.The results of the SEM examination of group B in the case of Light Curing and laser hardening showed clear homogeneity and better atomic distribution compared to other studied groups.

The objective of this study aimed to assess the effeats of the CO2 laser on the enamel cracks. The labial cracks of thirty extracted central incisors were irradiated with 4 Watts power and (0.4, 0.2 and 0.1) pulse durations. The laser used was CO2 laser with 10.6 μm in wavelength. The irradiated samples were sectioned into ground cross sections and examined under polarizing microscope. Enamel cracks can not be welded completely using CO2 laser irradiation. Although the formation of superficial glaze layer, there was a tendency to increase in the separation of the crack sides as the pulse duration of the laser increased

The objective of this study aimed to assess the relation between various CW CO2 laser parameters and the thickness of the surface zone in the created carieslike lesion.A total of twenty four extracted human premolar teeth were irradiated with three various power densities (63.66, 31.83, and 15.9) W/cm2. The CO2 laser system emitted laser with 10.6m in wavelength. All samples were subjected to 3.5 pH lactic acid for 21 days to form carieslike lesion. The crowns after that were sectioned into ground cross sections and the surface zone thicknesses were measured under a polarizing microscope.Continuous wave (CW) CO2 laser had a noticeable effect on the prominence of the surface zone. The mean of the surface zone thicknesses found to be directly related to the power density of CW CO2 laser.