Ultra-short laser pulses (USLP) have the potential for materials processing with almost no collateral thermal or mechanical damage. Thus they are well suited for hard tissue preparation in dentistry. But since sharp focusing has to be applied to reach the high intensities required for plasma-mediated ablation, the small focal spot has to be scanned over a larger area representing the cross section of a usual dental drill. This paper investigates cavity shape and morphology for two different pulse lengths, as longer pulses would allow access to cheaper laser sources for later industrial development of a medical device. 700 fs and 12 ps laser pulses were applied on plain human dentine slices with a pulse repetition rate of 35 kHz using a newly developed rotating scanner working in r/φ-coordinates. Cavity shape and morphology of different scanning patterns were evaluated using ESEM and 3D light microscopy.
Autori
Martin Strassl
Ariej Yousif
Ernst Wintner
