Sentence:  In this author's opinion, one can state without a doubt that the Endotec is a step forward, since it incontrovertibly proves that the “<WSD>lateralists</WSD>” have also realized that by softening the gutta-percha with heat and subjecting the mass thus obtained to pressure (vertical and/or lateral) one obtains better results! 
Meaning of the word marked with <WSD> tags:  One who favors a lateral approach or explanation over one that involves a different direction.