TY JOUR TI ESTIMATION OF PREVALENCE OF MAIN PERIODONTAL PATHOGENS AT WORKERS OF PETROCHEMICAL PRODUCTION WITH CHRONIC PERIODONTAL DISEASES KW petrochemical production KW chronic periodontitis KW red complex KW PCR JO Actual problems in dentistry AU Zaydullin, I.I. AU Karimov, D.O. AU Valeeva, E.T. AU Galimova, R.R. AU Kabirova, M.F. PY 2018 IS 14 PB TIRAZH Publishing House