In vitro study of pulp blood flow based on laser speckle contrast imaging

The aim of this study is to develop an ex vivo dental pulp blood flow model and assess variations in flow velocity using laser speckle contrast imaging (LSCI). Furthermore, we seek to quantitatively examine the impact of various flow rates, dentin block thicknesses, and capillary inner diameters on LSCI detection outcomes.

Polypropylene capillaries were inserted into 50 isolated teeth, followed by the injection of a 1 % intralipid solution into the capillaries. A coherent light source is used to illuminate the surface of the dental crown in LSCI, and the speckle images of the crown are captured by a detector at varying flow rates. The Speckle Flow Index (SFI) was computed using a time-based algorithm. A quantitative analysis was then conducted to assess the impact of flow rate, dentin thickness, and capillary diameter on the LSCI detection outcomes.

Utilizing the time-based algorithm, SFI values were determined for 50 isolated teeth across various flow rates, and there were significant differences between SFI values at different flow rates (p<0.05). Quantitative analysis further revealed a robust positive correlation between flow velocity and SFI value, a pronounced negative correlation between total dentin thickness and SFI value, and a negative correlation between capillary diameter and SFI value.

LSCI demonstrates the capability to detect alterations in blood flow velocity within an in vitro dental pulp blood flow model, showcasing its significant potential for clinical application in assessing dental pulp vitality.