Is it possible to anesthetize palatal tissues with buccal 4% articaine injection?

The aim of this study was to evaluate the presence of probable diffused local anesthetic solution at and anesthesia of palatal tissues after buccal injection of 4% articaine hydrochloride (HCl) with 1:100,000 epinephrine or 1:200,000 epinephrine at the premolar and molar region.

Thirty volunteers received maxillary buccal injections of 4% articaine HCl with 1:100,000 epinephrine or 1:200,000 epinephrine bilaterally to the first premolar or first molar. Magnetic resonance images were obtained before and 5 minutes after local anesthetic injections, and a visual evaluation was done to determine the presence of local anesthetic solution at palatal tissues. Anesthesia of palatal tissues after buccal injection was assessed by needle-prick stimulation pain with a visual analog scale (VAS). The Kruskal-Wallis test was used for comparison of the VAS values.

The visual evaluation of the magnetic resonance images did not show any signal change as an indicator of the presence of local anesthetic solution at the palatal region. Most of the volunteers described moderate or severe pain with needle-prick stimulation. The mean VAS score for needle-prick stimulation was 86.33 +/- 39.45 mm (1:100,000 epinephrine) and 87.0 +/- 36.28 mm (1:200,000 epinephrine) in the first premolar region and 57.20 +/- 46.69 mm (1:100,000 epinephrine) and 75.53 +/- 49.78 mm (1:200,000 epinephrine) in the molar region (P > .05).

We could not establish the presence of anesthesia or 4% articaine HCl at the palatal tissues after buccal injection. Maxillary tooth removal without palatal injection requires further objective investigations.