title: Atomic analysis and hardness measurement of the cavity prepared by laser.
abstract: The purpose of this study was to compare the compositional changes and microhardness of the cavity floor prepared by erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser irradiation with those of the conventional bur-prepared cavity. A total of 16 extracted human molar teeth (with no carious lesions or repairs) were selected for this study. On the buccal and lingual (palatal) surfaces of each tooth, cavities (diameter 3 mm, depth 2 mm) were prepared with an Er,Cr:YSGG laser system (Waterlase MD(TM), USA) and high-speed turbine. The cavities were cross-sectioned and subjected to atomic analysis by scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDX) and Vickers hardness test. Statistical analyses were performed with t-tests. Surface characteristics of the prepared cavities were also investigated by SEM. No significant differences were found between the calcium/phosphorus (Ca/P) ratio and Vickers hardness of laser- and bur-prepared cavities. The SEM observation revealed that the lased cavity surface was irregular, and there was also an absence of smear layer; the orifices of dentinal tubules were exposed. Microhardness measurement of the cavity floor confirmed that the Er,Cr:YSGG laser produced a clean-cut surface of the cavity.
authors: School of Dentistry/Laser Research Center, Research Center for Science and Technology In Medicine, Tehran, Iran. shahabis@tums.ac.ir
authors: Sima
authors: S
authors: Shahabi
authors: Somaeh
authors: S
authors: Zendedel
mesh_terms: D002118:Calcium / Q000032:analysis; D003737:Dental Cavity Preparation / Q000379:methods*; D006244:Hardness; D006245:Hardness Tests; D006801:Humans; D066298:In Vitro Techniques; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D008855:Microscopy, Electron, Scanning; D008963:Molar / Q000502:physiology / Q000528:radiation effects / Q000648:ultrastructure; D010758:Phosphorus / Q000032:analysis
chemical_list: D010758:Phosphorus; D002118:Calcium