Testing the Anesthetic Effectiveness of Three Different Dental Local Anesthetics Injected Next to a Lower First Molar

Anesthetic Efficacy of 4% Articaine With 1:100,000 Epinephrine, 4% Prilocaine With 1:200,000 Epinephrine, and 4% Lidocaine With 1:100,000 Epinephrine as a Primary Buccal Infiltration in the Mandibular First Molar.

Infiltration (injecting next to the tooth) injections are common in dentistry and a number of studies have shown that articaine anesthetic, when injected next to the tooth as a supplemental injection, works very well following a typical inferior alveolar (lower jaw) nerve block. No study has compared 4% articaine with 1:100,000 epinephrine, 4% prilocaine with 1:200,000 epinephrine, and 4% lidocaine with 1:100,000 epinephrine in mandibular (lower jaw) infiltration injections of the first molar. The purpose of this prospective, randomized, double-blind, crossover study is to compare the degree of anesthesia obtained from the three solutions as a primary infiltration injection next to the mandibular first molar. The investigators also will record the pain of injection and postoperative pain.

Using a crossover design, 60 adult subjects will receive three injections consisting of a primary mandibular first molar infiltration of 1.8 mL of 4% articaine with 1:100,000 epinephrine, 1.8 mL of 4% prilocaine with 1:200,000 epinephrine, and 1.8 mL of 4% lidocaine with 1:100,000 epinephrine in three separate appointments spaced at least one week apart. With the crossover design, 180 infiltrations will be given for the first molar and each subject will serve as his or her own control. Ninety infiltrations will be administered on the mandibular left side and ninety administered on the mandibular right side. The order of the three injections will be assigned randomly and the dentist and subject will be blinded about which anesthetic the subject is given. The anesthetics used in this study are not experimental. An electric pulp tester will be used to test the lower back teeth (molars and premolars) for anesthesia in 3-minute time intervals for a total of 60 minutes. The pain of injection and postoperative pain will be recorded in a survey. The data will be statistically analyzed.

Inclusion Criteria:

• between the ages of 18 and 65 years.
• in good health (ASA classification II or lower).
• able to provide informed consent.

Exclusion Criteria:

• allergy to articaine, lidocaine or prilocaine.
• history of significant medical problems (ASA classification III or greater).
• depression (taking tri-cyclic antidepressant medications to control).
• have taken CNS depressants (including alcohol or any analgesic medications) within the last 48 hours prior to testing.
• lactating or pregnant.
• inability to give informed consent.