TY JOUR TI COMPARATIVE CHARACTERISTICS OF TEETH HARD TISSUES WITH DIFFERENT WAYS OF PREPARATION KW ultrasonic tooth preparation KW morphology of enamel and dentin KW scanning microscopy tooth JO Actual problems in dentistry AU Chechun, N.V. AU Bondarenko, O.V. AU Sysoeva, O.V. AU Tokmakova, S.I. PY 2015 IS 11 PB TIRAZH Publishing House