Abstract
The aim of this study is to determine the ototoxicities of boric acid in alcohol (BAA) and Castellani solutions by means of distortion product otoacoustic emission (DPOAE). A total of 28 rats were randomly divided into four groups, each group consisting of 7 animals. Then, 0.1 mL Castellani solution, 0.1 mL BAA (4% boric acid solution prepared with 60% alcohol), 0.2 mL (40 mg/mL) gentamicin and 0.2 mL saline were dropped to right outer ear canals of rats in groups 1, 2, 3 and 4 respectively, twice a day, for 14 days. DPOAE values obtained on days 0 and 14 were statistically compared for the values obtained at 750-8000 Hz frequencies. A statistically significant decrease was found on day 14 compared to day 0 values in Castellani group at all frequencies (p < 0.05). In BAA group, there was a statistically significant decrease between frequencies 1500 and 8000 Hz on day 14 (p < 0.05).We found that Castellani and BAA were ototoxic. BAA and Castellani solutions should be avoided in patients with tympanic membrane perforations, ventilation tubes and open mastoid cavities.