Pain perception during injection of local anesthesia in pedodontics

Few studies have examined pain levels for the injection of local anesthesia in children, though it is a routine technique in pediatric dentistry. The objective of the study was to evaluate the difference in the assessment of procedural pain by the child, parent, dental practitioner, and independent observers during injection of local anesthesia for dental treatment in pediatric dentistry.

In total, 27 male and 22 female children (5 to 17 years of age, mean ± SD 9.8 ± 4.0 years) received local anesthesia (LA) via infiltration or mandibular alveolar blocks according to a standard protocol. After the dental treatment, the children assessed the pain levels for the procedures on a visual analog scale (VAS), while their parents and the dental practitioner used a numeric rating scale (0 to 10). Independent observers also assessed pain via video tape for an evaluation after blinding. The heart rate was monitored continuously during the procedure. The Bland-Altman method was used to quantify the comparison between pain ratings.

The assessed level of pain by dental practitioner, parent, and child during injection of LA differed clearly (child: 3.94 ± 2.71; parent: 3.31 ± 2.60; dental practitioner: 3.02 ± 1.98; video observer 1: 1.76 ± 2.56; video observer 2: 1.89 ± 2.55). In 42.9% of cases the dental practitioner's rating and the self--reported pain by the child during injection of LA differed by ≥ 2 on the numeric rating scale, which is clinically a highly different and relevant assessment.

As pain perception in children during the injection of local anesthetic and its assessment varies considerably depending on the assessing person and the treated child, dental practitioners and researchers should be cautious in interpreting the patient's pain perception.