Pilot Study: Comparison of Buffered 1% vs. Unbuffered 2% Lidocaine in Pediatric Subjects; Clinical Outcomes

Local anesthesia is an integral part of clinical pediatric dental practice, but it has challenges. It can be uncomfortable for children, and the risk of adverse events limits how much is used. Some evidence suggests benefits of buffering local anesthetics including equal effect with less pain on injection. These findings have not been replicated and validated among pediatric populations, creating a gap in the knowledge base. To address this knowledge gap and contribute to the evidence base on safety and efficacy of local anesthesia in pediatric dentistry, this investigation proposes to compare the anesthetic effects of buffered 1% lidocaine with those of unbuffered 2%, among children.

The specific aims of this investigation are to determine differences between buffered 1% and unbuffered 2% lidocaine (both with 1:100,000 epinephrine) used for inferior alveolar nerve block (IAN) anesthesia, in the following domains:

1. Pain experience on injection, time to onset following the administration, and time to recovery [subjective]
2. Blood lidocaine levels 15 minutes following the administration and duration of pulpal anesthesia [objective]

Null Hypotheses:

1. No difference exists in anesthetic effectiveness for pulpal anesthesia after intraoral IAN block between buffered 1% Lidocaine with 1:100,000 epinephrine as compared to unbuffered 2% Lidocaine with 1:100,000 epinephrine.
2. No differences exist in peak blood lidocaine levels, pain on injection, time to lip numbness, and duration of anesthesia between the two drug formulations.

Randomized subjects will be injected orally for bottom jaw anesthesia, with 3cc of buffered 1% lidocaine (30mg) 1:100,000 epinephrine or 3cc unbuffered of 2% lidocaine (60mg) 1:100,000 epinephrine. The injectable volume of the buffered formulation will include 0.3cc of 8.4% sodium bicarbonate.

One faculty member in the Department of Pediatric Dentistry at the University of North Carolina (UNC) School of Dentistry will administer the drugs in the Pediatric Dentistry clinic. The same clinician will administer injection to the same subjects at both visits. Clinicians and subjects will not know which drug formulation is given at which appointment.

A clinician will measure the level of discomfort on injection, how long it takes for the lip to be numb, how long it takes for the first molar tooth in that area to be numb, how long it takes the local anesthetic to wear off, and how much of the anesthetic is in the blood.