Influence of New Bioactive Material on Compound Nerve Action Potentials

Methods: Rat sciatic nerves (n=5/group) were isolated surgically and placed between two platinum electrodes in a bath containing Tyrode solution, which allowed for stimulation and recording of compound action potentials (CAP). Each nerve was repeatedly stimulated with an electrical stimulus (3V amplitude, 0.05 ms pulse width). Raw data were processed digitally by amplifying with x500 gain and 2 kHz low pass, Q=0.070 filtering. Biopac LabPro V.3.7 software (Biopac Inc. CA, USA) was used in recording and analyzing the data. The minimal threshold required for evoking a compound action potential was recorded. The experiments were performed at supramaximal stimulation. The nerves were stimulated for at least 60 min prior to experiments. Thereafter, the test material (DiaRoot BioAggregate)was brought into contact with the nerves and the evoked compound action potentials (CAP) were recorded at 0-10,10-20, 20-30, 30-40, 40-50, 50-60 min time intervals.

Results: The CAP amplitudes (V) in control and test groups for each respecitve time intervals were; 0,022, 0,022, 0,020, 0,020, 0,019, 0,019 and 0,023, 0,023, 0,0230, 0,023, 0,023; respectivey. All CAPs were recovered following irrigation of nerves with fresh Tyrode solution.

Conclusion: The tested endodontic repair biomaterial showed neglectible and transitory blockage of CAPs on isolated sciatic nerve in vitro.