An oral care system (300, 400) configured to obtain a plurality of optical signals to be used for assessing a health parameter of gingival tissue of a user, the oral care system comprising:a force-generating module (52) configured to apply a momentary force to the gingival tissue by applying a burst of compressed air or a burst of liquid to the gingival tissue;a sensor (28) configured to obtain the plurality of optical signals from the gingival tissue over time after the momentary force has been applied.