RESUMO
Ultrasound transmission and reflection at the interface between restorative material and tooth tissue have been investigated using experimental flat-parallel models and whole extracted human teeth with restorations. It has been found that in the case of good bonding the ultrasound wave energy practically does not reflect at the cement/dentin interface and propagates into dentin layer. If any microscopic cavity had been formed between cement and dentin, the most part of the acoustic energy would be reflected from the interface between cement and gaseous or liquid contents of that cavity. The results acquired have been used for the interpretation of morphological peculiarities of the adhesive bonding area in visual images, non-destructively obtained in acoustic microscope ultrasound frequency - 50 MHz. The differences discovered could be used as a base for the design and development of new ultrasound methods for the restorative materials bonding evaluation as well as for secondary caries revealing.
