Evaluation of Iraqi Phosphorite from Akashat Mine as a Polishing and Whitening Material in Human Dentistry: A Study in Medical Geology

The aim of this study is to prepare and assess the phosphorite efficiency for removal extrinsic stains and debris from the human teeth and luster increasing via a set of laboratory experiments. The phosphorite is composed of carbonate-fluorapatite, while the human teeth are composed of hydroxyapatite. Polishing of the human teeth was conducted by using 68, 46, 30, and 18 m grain sizes of phosphorite powder which are equivalent to 260, 325, 600, and 1200 mesh respectively. Buffing stage wes gently done later using diamond paste of 7 and 2.5 m grain size. The surface roughness (Ra m) of the target (human teeth) which was measured after each stage positively correlated to the grain size, while reflectance (R %) was of negative correlation. The reflectance values of the sharp human tooth are 0, 1.4, 2.8, 3.3, 3.6, 4.7, and 4.5 % for the surface roughness values of 45.2, 39.8, 32.6, 25.6, 10.3, 7.5, and 4.0 m. The reflectance values of the wide human tooth are 0, 1.1, 2.2, 2.7, 3.5, 4.2, and 4.6 % for the surface roughness values of 40.2, 34.6, 27.7, 21.3, 9.0, 7.5, and 4.0 m. The phosphorite powder of grain size 18 m is the best abrasive for removal the extrinsic stain which is a deposition of chromogenic materials on the external surface (enamel and dentin) of the human teeth.