Evaluation of 2-Stage Injection Technique in Children

Does a New Modification of the Two-Step Injection Technique for Inferior Alveolar Nerve Block Reduce Pain Compared to the Conventional Technique? A Randomized Clinical Trial

Background. The ability to control pain is an essential part of dental procedures and the need for optimal pain control and reduction of discomfort is the primary concern of every dentist. This study aims to compare the pain and vital signs during inferior alveolar nerve block between conventional and a new modification of the two-step injection techniques. Methods. In this institutional single-blind randomized clinical trial, attendees of dental school at Mazandaran University of Medical Sciences from February to May 2022 were included. Inclusion criteria were 20–60 years old and healthy (ASA1) individuals who were willing to participate in this study. Individuals who were taking medications affecting their understanding of pain and patients with active infections at the injection site were excluded. These individuals were divided into two groups. First, superficial anesthesia was performed and afterward, conventional and two-step injection techniques were performed. For the two-step injection method, 6 mm of the needle was injected into the mucosa and one-third of the local anesthetic solution was released from the computer-controlled injection toolkit. Afterward, a 25 mm 30-gauge needle was reinserted into the previous hole delivering the remaining local anesthetic. The pain during injection was measured by a patient-reported numerical rating scale (NRS). Moreover, vital signs were monitored immediately before and after the injection. Kolmogorov–Smirnov test, Mann–Whitney U test, independent T-test, and Fisher’s exact χ2 test were performed for statistical analysis (α = 0.05). Results. This study involved 32 adults aged between 20 and 50 years old with 1 : 1 female/male sex distribution. The pain score was significantly higher in the conventional injection technique compared to the two-step injection technique in all sex and age groups. There were no significant differences in vital signs between the conventional and two-step injection techniques. There was no significant difference in the mean pain scores of females and males, regardless of their injection techniques. Conclusion. Utilizing the two-step injection technique in patients for inferior alveolar block reduces pain during injection without altering patients’ vital signs significantly. This trial is registered with IRCT20220106053646N1.

Comparison of Patient Comfort During the First Stage of Conventional Versus Modified Two-Stage Inferior Alveolar Nerve Blocks in Pediatric Patients

Our aim was to compare the comfort of pediatric patients during the first stage of the conventional 2-stage inferior alveolar nerve block (IANB) versus the modified 2-stage IANB. This was a parallel group, single-blinded, randomized controlled trial. Pediatric patients meeting the inclusion criteria were randomly allocated to 1 of the 2 groups receiving IANB, group 1 (31 subjects) utilized a conventional 2-stage technique, and group 2 (33 subjects) utilized a modified 2-stage approach. Patient comfort was assessed indirectly by 2 observers using the Face, Legs, Activity, Cry, Consolability (FLACC) scale during the first stage of the injections. FLACC score data between the 2 groups were analyzed using the chi-square test, and interobserver reliability was measured using kappa statistics. During the first stage of the injections, lower FLACC scores of 0 indicating a relaxed/comfortable patient experience were found in 57.6% of group 2 subjects compared with only 25.8% group 1 subjects, which was a statistically significant difference (p-value .013). Interobserver reliability assessed using kappa coefficients (κ = 0.812) indicated excellent agreement. FLACC scores for the pediatric patients during the first stage of the modified 2-stage IANB technique were significantly lower than during the first stage of the conventional 2-stage IANB technique.

The effect of pre-anesthesia with a needle-free system versus topical anesthesia on injection pain of the inferior alveolar nerve block: a randomized clinical trial

OBJECTIVE

The aim of this study was to compare the effectiveness of pain control between a needle-free system and topical anesthesia applied prior to inferior alveolar nerve block (IANB).

MATERIALS AND METHODS

The present study was designed as a randomized controlled cross-over clinical study on 60 children (aged 6 to 12 years) requiring dental treatment with IANB in bilateral mandibular molars. As pre-anesthesia, topical anesthesia (TA) was applied on one side and the Comfort-in™ injection system (CIS) on the other side in two separate sessions before IANB. The injection pain during IANB, at both the needle insertion and solution deposition phases, was analyzed using the Wong-Baker Faces Pain Rating Scale (PRS) and the Face, Legs, Activity, Cry, Consolability Scale (FLACC). The data were analyzed using the Wilcoxon signed-rank test, Spearman correlation, and Mann-Whitney U test.

RESULTS

There were statistically significant differences between TA and CIS in subjective and objective pain evaluations during both the needle insertion and solution deposition. The use of a needle-free system in pre-anesthesia yielded a significant decrease in subjective and objective pain scores (p < 0.001). No statistical difference was found between TA and CIS in terms of patient preference, but patient preference for CIS was significantly higher in older patients (p < 0.01).

CONCLUSIONS

It was determined that the use of a needle-free system in pre-anesthesia yielded a decrease in injection pain of IANB.

CLINICAL RELEVANCE

Pediatric dentists should be aware of the new injection system in order to decrease the level of injection pain.