Injective anesthesia, in other words – the use of the needle, constitutes, together with the sounds of the handpieces, one of the fundamental triggers of the psychological framework of avoidance represented by dental anxiety. This specific causal aspect derives largely from traumatic episodes experienced, not necessarily experienced in the dentist’s chair (think of the vaccinations) nor, even less, related to cases of real malpractice.
Starting from these assumptions, the idea is to propose the possibility of a needleless anesthesia to the anxious patient. In general terms, this type of system is designed to lead the local anesthetic molecule contained in solution inside the vial tube to its target site through a carrier different from the common needle. It is obvious that the active phase of administration, i.e., the release of the anesthetic solution, is also an unpleasant component to be minimized as much as possible; a modern system of anesthesia delivery is also expected to develop this aspect.
In this regard, the Oliveira group has conducted a study aimed at comparing a needleless system, precisely considering, in addition to pharmacokinetic aspects (latency time and duration of the anesthetic effect), the extent of pain symptoms during the anesthetic procedure. Specifically, the evaluated system consists of a method of jet administration that does not involve the use of any needle, patented for skin use and even intraoral.
A total of 41 patients were involved in the restoration of both first lower molars by means of class I fillings in order to prepare the comparison according to a split-mouth model. Without previous topical anesthesia, which could have been a confusing factor, each patient received, in random order, a standardized volume (1.0 mL) of anesthetic solution, using the needleless technique and also through a common traditional dental syringe with a short 30 guage needle.
No significant differences were found between the two techniques in terms of onset time and duration of anesthesia.
Perhaps the most surprising fact, however, is probably that of the VAS scale relating to the painful stimulus during the administration phase; even from this point of view, in fact, the needleless technique has not brought significant advantages.
In conclusion, this work reminds clinicians, in addition to being able to prevent the patient from seeing the needle and its pathological consequences, how ensuring comfort during the delivery phase of anesthesia can also be advantageous.
In other words, it seems interesting to look from needleless to painless systems. In this sense, the clinician will prefer to investigate those systems with a proven reduction of painful injection stimulus supported by a sufficiently broad background in the scientific literature.