Lower alveolar nerve blocks are deemed the reference anesthesiological method in management of intraoperative pain at the level of the posterior mandibular region. However, it is a painful injection procedure when compared with local infiltration techniques and intraligament injections. Both the initial phase of needle insertion and the subsequent penetration phase induce pain in patients. Pressure changes during release constitute a significant source of discomfort for patients on an essentially iatrogenic basis.
Conceptually, injecting the anesthetic solution “slowly” is a safety measure, as well as the administration of the minimum effective dose, that is capable of increasing comfort. With the use of a conventional carpule syringe, however, the issue of dependence on the operator remains.
The computer-controlled local anesthetic delivery (CCLAD) system was developed with the rationale of exploiting the advantages of pressure control, exempting the clinician from this careful task, while still allowing for supervision of the overall procedure. A pump system manages the speed and the computer cancels out the differences in flow resistance.
Recently, the Gajendragadkar working group proposed a comparison of the conventional lower alveolar block technique and CCLAD as regards intraprocedural pain perception.
The study involved a total of 50 patients between 18 and 75 years of age, screened based on their scheduled treatments requiring bilateral inferior alveolar block. The trial investigation was carried out according to a split-mouth model, therefore each patient received the conventional lower alveolar block and, after one week, administration via CCLAD on the contralateral side, or vice versa. In order to minimize the carry-across effect, in fact, in 25 patients (randomly allocated according to the SNOSE technique), started with one method, while the remaining half of the sample started with the other method. In order to also reduce confounding factors, the same active ingredient was always been administered at the same dosage (1.8 ml, equivalent to one tubular injection vial), using a 1.5-inch needle and 30 gauge, albeit with different handpieces. In addition, in both cases the bidirectional rotation technique was used during needle insertion. After the injection procedure, each patient was asked to self-evaluate the pain stimulation by means of a visual-analogue scale (VAS).
The results show a significantly lower difference in the VAS score in findings relative to the group treated with CCLAD. This method was therefore, confirmed to be excellent in managing the injection pain stimulus.