Patient evaluation of a novel non-injectable anesthetic gel: A multicenter crossover study comparing the gel to infiltration anesthesia during scaling and root planing. - van Steenberghe,D.; Bercy,B.; De Boever,J.; Adriaens,P.; Greers,L.; Hendrickx,E.; Adriaenssen,Ch.; Rompen,E.; Malmenäs,M.; Ramsberg,J. (J Periodontol, 2004)