The Impact of CO2 Laser and Hydroxyapatite Nano Particles on Dental Enamel

Background laser technology holds great promise for medical and dental applications and carbon dioxide (CO2) laser is still one of the most beneficial type. A laser beam is created from a substance known as an active medium, which when stimulated by light or electricity produces photons of a specific wavelength. This beam results in an interaction between light and biological constituents of tissues that is converted into heat, ending with structural and chemical changes in tissues. Dental caries is a dietary carbohydrate-modified bacterial infectious disease. The basic mechanism of dental caries is demineralization through the acids attack. Lasers are expected to be one of the most promising new technical modalities for the treatment of dental diseases. Nanotechnology is the manipulation of matter on the molecular and atomic levels. The developed interest for nanotechnology in many fields, is producing interesting and imminent applications as tissue repair and replacement especially in bones and dental mineralized tissues. Aim of the study this study was conducted to test the impact of CO2 laser and Hydroxyapatite nanoparticles on the change in chemical composition of enamel and the morphological changes in enamel ultra-structure. Materials and Methods Teeth samples in this study consisted of 66 maxillary first premolars, divided into six groups one control group and five study groups, each group consisted of 11 teeth, one tooth for Scanning Electron Microscope examination (SEM), while other 10 teeth for Energy dispersive spectroscopy ( EDS) analysis. A position of circular window on the buccal surface of each tooth was standardized. To induce caries lesion on enamel surface, pH cycling procedure was followed. Lasing was carried out using CO2 laser system at specific power, time and mode. Hydroxyapatite nanoparticles used in the study was 20nm, the concentration was determined to be 10 %. The weight percentages (wt %) of Calcium, Phosphorus, Oxygen were determined using EDS analysis to evaluate the change in chemical composition of enamel, SEM was used to demonstrate the morphological changes in enamel ultra-structure. Results For all groups, the data obtained by (EDS) analysis revealed that for both Calcium (Ca) and Phosphorus (P), the mean atomic percentage was reduced after demineralization and after laser irradiation. An increase in the atomic percentage for both elements after treatment with other agents was noticed, with the maximum value recorded for the group treated with Laser + hydroxyapatite nanoparticles. For Oxygen (O), the result was opposite to that of (Ca) and (P). Statistical analysis were highly significant (pgreater than0.01) for all of the three elements. Examination of enamel surface using SEM revealed an ultrastructural change had occurred beginning with loss of enamel normal architecture after demineralization. After CO2 laser irradiation, cracks and melted and recrystallized areas were noticed. After treatment with hydroxyapatite nanoparticles, hydroxyapatite nanoparticles + CO2 laser and CO2 laser + hydroxyapatite nanoparticles most of micropores were occluded and surface defects were reconstructed. Conclusion Treatment of enamel surface with CO2 laser + hydroxyapatite nanoparticles gave the best result regarding EDS analysis and SEM examination, so such treatment could be considered as a method of preventing demineralization and encouraging remineralization of enamel.