https://www.selleckchem.com/products/guanosine.html To investigate the subgingival microbiological profiles of patients with periodontitis, to determine their stage and grade scores and to evaluate the differences in the microbiota among different stages and grades. Materials and Methods Sixty-seven (n = 67) periodontitis patients were selected. Periodontitis staging and grading, following the 2018 classification system, were defined. Following a clinical examination, subgingival samples were taken from the deepest periodontal pocket of each quadrant for cultivation, identification and quantification. The prevalence, proportion and counts of nine selected periodontal pathogens were determined, and differences between periodontitis stages III and IV and grades B and C were assessed. Results All nine cultivable periodontal bacteria were detected, of which the most prevalent was P. intermedia (91.0%) and the least prevalent were E. corrodens (9.0%) and C. ochracea (9.0%). The frequency of detection of the two main target pathogens, A. actinomycetemcomitans and itis patients, whereas the counts of P. gingivalis and A. actinomycetemcomitans were similar between grades and stages. Conclusion Our study suggests that relevant differences between the various grades of periodontitis exist only in the numbers of F. nucleatum. Prevalence and quantities of other cultivable species between different stages and grades of periodontitis seem to be similar. The aim of the present research was to analyse the effects of two bleaching agents, on the enamel crystallography by means of X-ray diffraction. Twelve human sound posterior teeth, were collected for the present study (n = 12) and from each tooth two enamel slabs were obtained and randomly assigned to one of two different bleaching protocols. The first protocol involved an in-office bleaching agent (hydrogen peroxide 37.5%/ SDI Polaoffice+), and the second an at-home whitening product (carbamide peroxide 16%/ PHILIPS Zoom! NiteWhi