Effects of the iontophoresis of lignocaine with epinephrine into exposed dentine on the sensitivity of the dentine in man

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

“…[14][15][16] The VAS scores recorded from the carious teeth when tested with air-blast and probing stimuli before treatment, were substantially lower than those obtained with the same stimuli under similar conditions from normal teeth. 1 This was probably because the dentine in the normal teeth had been etched, which would have both removed the smear layer left by drilling, unblocking the mouths of the tubules, and left the dentine surface more compliant than normal. These changes may have allowed the air-blast to cause more fluid to be lost from the tubules and the probing to cause a greater displacement of the tubule contents; both resulting in a greater excitation of the hydrodynamic receptors in the normal than in the carious teeth.…”

“…[2][3][4][5] In the present experiments, the possibility of anaesthetising carious molars for cavity preparation using a technique similar to that described by Thongkukiatkun et al 1 was investigated. Preliminary experiments indicated that the original technique did not provide adequate anaesthesia for the treatment of carious teeth and for this reason the iontophoretic current was increased from 120 to 200 mA and it was applied for 2 min rather than 90 s. In every other respect, the method of treatment was as described by Thongkukiatkun et al 1 …”

“…The carious dentine in these teeth was however much more resistant to anaesthesia than the freshly exposed, normal dentine that was investigated using a similar procedure in a previous study. 1 The same solution was applied to the dentine in both studies (20% w/v lignocaine HCl with 0.1% w/v epinephrine HCl) but whereas the normal dentine was immediately anaesthetised when an anodal current of 120 mA was passed from the solution into the dentine for 90 s, the carious dentine required a current of 200 mA, and this had to be applied for much longer. Most teeth were anaesthetised after between 2 and 10 min, but even after a total of 14 min, 7 out of 56 teeth (12.5%) were not anaesthetised to the level that would permit dentine to be drilled without pain.…”

“…1 These experiments were carried out on freshly exposed, healthy dentine; if the technique could be used for cavity preparation in carious teeth, it would avoid the need for the administration of local anaesthetics by injection, which causes patients pain and To determine the effectiveness of the iontophoretic delivery of lignocaine with epinephrine through carious dentine for pain control during cavity preparation.…”

Iontophoretic Drug Delivery in the Oral Cavity

“…Both methods were found to reduce hypersensitivity, and iontophoresis was more effective clinically and had fewer failures compared to the bonding agent application [ 94 ]. In addition to fluoride, iontophoretic delivery of lignocaine into exposed dentin was examined and found to be effective in anaesthetizing dentin-exposed teeth [ 58 , 74 ].…”