مریم فضلی - Dept. of Oral Health, Zanjan University of Medical Sciences, Zanjan, Iran
پروین نصیری - Dept. of Occupational Health, School of Public Health and Institute of Public Health Research, Tehran University of Medical Sciences, Tehran, Iran
زهرا حسنی - Dept. of Occupational Health, Zanjan University of Medical Sciences, Zanjan, Iran

Background and Objective: There are many chemical, physical and biological hazards which are threatening the dentistschr('۳۹') health. In this study we assessed the effect of noise on Zanjan dentists hearing loss as one of the dentistry physical hazards. Materials and Methods: This cross sectional study was performed on all zanjan dentists in ۲۰۰۶-۷. All dentists were examined by audiometer (CA۷۶ and AC۴۰). The exclusion criteria were hearing accidents and diseases. The data were statistically analyzed by T test ( =۰.۰۵). Results: Noise induced hearing loss was observed in most cases. Left ear was more susceptible than right ear. The men had more hearing loss than the women. (P value on Freq ۸۰۰۰ HZ= ۰.۰۰۱). Deutists with seniority of ۱۰ years and over had more hearing loss than who have seniority of less than ۱۰ years (P value on Freq ۸۰۰۰ HZ= ۰.۰۰۴). The dentists in the age of ۴۰ years old and over had more hearing loss than the ages below ۴۰ year (P value on freq ۸۰۰۰ HZ in the left ear = ۰.۰۰۷, in the right ear = ۰.۰۱۹). Left ear had more hearing loss than right ear. Noise induced hearing loss in extra–speech frequencies was more than speech frequencies. The noise frequency of dental equipments was between ۷۰ to ۱۰۵ db. Conclusion: Noise induced hearing loss which has threatened the dentistschr('۳۹') health is an incurable problem that must be prevented. Regular audiometric exam, use of hearing protection devices and also the occupational health regulations must be implemented for dentists in order to reduce the risk of noise induced hearing loss.

Key words: Hearing loss, Noise, Noise frequency, Dentists.