The topic of managing the pH of the tubular injection vial’s content has already been discussed in articles published here.
The pediatric patient is perhaps the most susceptible to fear of anesthetic injection and, in particular, to the pain associated with it. Aside from the innate fear of needles, the trigger of anesthaesia can be explained as the burning sensation perceived on the soft tissues, also linked to the difference in pH, a thousand times more acidic than that of the subcutaneous tissue. By bringing this back close to physiological values, just before administration,
Apart from the sensation directly linked to the infiltration, several studies have indicated alkalinizing the pH as a way to improve the pharmacodynamic effects of the molecules used. Kattan’s systematic review (JADA 2019) established that buffered local anesthesia has greater efficacy in adults compared with non-buffered, with a likelihood ratio of 2.29.
Recently, Meincken et al. conducted a study, published in Pediatric Dentistry, aimed at evaluating injection pain and onset time in pediatric patients when using buffered local anesthetic, compared with a non-buffered control.
The sample consisted of 65 patients aged 7–11, all effectively old enough to provide good dental cooperation.
The study was designed according to a prospective, randomized, single-blind, split-mouth model. In other words, patients received local anesthesia alternately with both anesthetic solutions. As for the starting side, the dentists proceeded with the criterion of extending carious lesions.
Pain perception was measured with the help of the Wong-Baker FACES pain rating scale and the Ohio State University behavior rating scale.
A total of 130 inferior alveolar nerve block procedures were performed. Using buffered lidocaine (2% associated with 1:100000 adrenaline), the average onset time was 2.22 minutes, lower than that obtained with non-buffered solution (2.53 minutes) but not significantly so. Contrary to expectations, the pain measurements, although reduced, were also not significantly lower in the case group.
Beyond the investigation’s possible limits, the pediatric subject is likely – referring back to the beginning of this discussion – to have a pain perception and a psychological component which can influence the results sought in the study. In approaching these subjects, then, it is also wise to orientate on alternative methods which can ensure control of pain stimulation during the anesthetic procedure.