Effectiveness of the anterior and middle superior alveolar nerve block (AMSA) technique in single-session endodontic treatments
Supraperiosteal infiltration constitutes the traditional local anesthetic approach in the maxillary arch. The procedure requires that the needle be directed near the hypothetical root apex site, an approach that can lead to failures because of significant curvatures, as can be observed in the premolar and molar regions.
Another possible limit is found for treatments that routinely tend to continue over time. In this sense, an example consists of the choice to perform an endodontic procedure in a single session. If possible, this option will be advantageous compared to extending it over several consecutive sessions but, it will probably lead to longer therapeutic and even anesthesiological time spans.
In addition, some authors suggest the need for palatal administration, in order to ensure complete comfort when a rubber dam is placed.
In order to reduce the overall number of injections and their sequelae, the AMSA (anterior middle superior alveolar nerve block) technique may be an alternative.
Recently, a work conducted by the Patil group and published in Clinical Oral Investigations has proposed to evaluate the effectiveness of anesthesia using the AMSA technique in the context of a single-visit endodontic treatment.
The study included a total of 60 patients, of both sexes and aged between 16 and 60 years, each with a dental element (20 incisors, 4 canines and 36 premolars) that required endodontic treatment scheduled in a single session.
The preparation involved the implementation, after topical anesthesia of the injection site, of the AMSA technique by means of a conventional syringe with a 26 gauge needle. The operator administered an amount of anesthetic equal to 1.5 mL of 2% lidocaine-based solution associated with vasoconstrictor (epinephrine) 1: 80000. The injection target was identified on the hard palate according to the procedure described by Malamed.
Pulp viability was electrically tested prior to anesthesia. In this phase, 17 patients reported no pain, 40 reported mild pain, and the remaining 3, moderate pain.
The degree of depth of anesthesia was assessed by means of a visual-analogue scale (VAS) at 15, 30, 60, and 90 minutes.
In 5 cases, equal to 8.33% of the sample, exactly at the level of an incisor and 4 premolars, an additional administration was required after 15 minutes. The effective rate reported is, therefore, equal to 91.67%.
The depth was thus adequate throughout the investigated period.
In conclusion, the authors indicated the AMSA technique as a valid alternative in cases of endodontic treatment completed in a single session.