[Experimental studies on the effectiveness of intraligamental anesthesia].

In this study the effectiveness of the periodontal ligament injection was tested in rats. Anesthetic solutions with carbon dye were injected into the crestal periodontal ligament space under back-pressure. Vital microscopic observations showed that the solution spreads via an intraosseous path into the vessels of the pulp. These results support the contention that the periodontal ligament injection is intravascular in nature. Therefore, possible cardiovascular responses to periodontal ligament injections containing catecholamines must be considered.