The iontophoresis of lignocaine with epinephrine into carious dentine for pain control during cavity preparation in human molars

• 20% Lignocaine +0.1% epinephrine were applied to carious dentine by iontophoresis.
• A current of 200 μA was applied for 2–10 min in 56 carious molars.
• The dentine was anaesthetized for cavity preparation in 49 (87.5%) of the teeth.
• The method could be useful in patients with haemophilia or a needle phobia.

ObjectiveTo determine the effectiveness of the iontophoretic delivery of lignocaine with epinephrine through carious dentine for pain control during cavity preparation.DesignThe experiments were carried out on 56 carious molars that required class I restorations in 42 subjects (aged 15–20 years). The overhanging enamel and soft caries were removed then the sensitivity of the exposed dentine was tested with drilling, probing and air blast stimuli. The subject indicated the intensity of any pain produced by marking a visual analogue scale (VAS). The cavity was then filled with 20% w/v lidocaine with 0.1% w/v epinephrine and a 200 μA iontophoretic current applied for 2 min after which the sensitivity of the dentine was re-tested. If the dentine was not anaesthetized, the treatment and testing were repeated up to 6 times.ResultsThe total duration (min) of iontophoresis required to anaesthetize the dentine was: 2 in 7 teeth, 4 in 17 teeth, 6 in 14 teeth, 8 in 4 teeth, and 10 in 7 teeth. The remaining 7 teeth were not anaesthetized even after 14 min of iontophoresis.ConclusionsThe iontophoretic delivery of lignocaine with epinephrine anaesthetized dentine for cavity preparation in 49 of 56 (87.5%) of carious molars.