This research aimed to study a polarized laser speckle contrast imaging (LSCI) system to assess the pulp blood flow, where the ability of vertically polarized LSCI (vp-LSCI) and the non-polarized LSCI (np-LSCI) systems has been compared through space contrast algorithm and time contrast algorithm. The results showed that the vp-LSCI system could detect a wider contrast dynamic range in the pulp flow, approximately 1.5–2 times than that of the np-LSCI system. The time contrast algorithm detected small velocity changes of 0.03–0.07 mm/s, and its detectability index was 5–10 times than the space contrast algorithm. The vp-LSCI system combined with time contrast algorithm greatly improves the ability of laser speckle to detect pulp blood flow and can detect a wider range of blood flow velocity and smaller changes of blood flow. It indicated that our system may be a promising tool for clinical assessment of pulp blood flow. [ABSTRACT FROM AUTHOR]