Noise Exposure Assessment in a Dental School

OBJECTIVES: This cross-sectional study was performed in the Dental School of Prince of Songkla University to ascertain noise exposure of dentists, dental assistants, and laboratory technicians. A noise spectral analysis was taken to illustrate the spectra of dental devices. METHODS: A noise evaluation was performed to measure the noise level at dental clinics and one dental laboratory from May to December 2010. Noise spectral data of dental devices were taken during dental practices at the dental services clinic and at the dental laboratory. A noise dosimeter was set following the Occupational Safety and Health Administration criteria and then attached to the subjects' collar to record personal noise dose exposure during working periods. RESULTS: The peaks of the noise spectrum of dental instruments were at 1,000, 4,000, and 8,000 Hz which depended on the type of instrument. The differences in working areas and job positions had an influence on the level of noise exposure (p < 0.01). Noise measurement in the personal hearing zone found that the laboratory technicians were exposed to the highest impulsive noise levels (137.1 dBC). The dentists and dental assistants who worked at a pedodontic clinic had the highest percent noise dose (4.60 +/- 3.59%). In the working areas, the 8-hour time-weighted average of noise levels ranged between 49.7-58.1 dBA while the noisiest working area was the dental laboratory. CONCLUSION: Dental personnel are exposed to noise intensities lower than occupational exposure limits. Therefore, these dental personnel may not experience a noise-induced hearing loss.

The Method to Keep Aseptic Dental Burs Rust-Free

This research studied the methods to keep aseptic dental long steel burs rust-free. The researcher used 3 different methods to store dental burs. The first method was storing in a zero vacuum package. The second method involved storing in a sealed bottle containing silica gel. As a control, the third method was storing in a box placed in a drawer. Each batch consisted of 50 dental burs and after being stored for three months, the number of burs with signs of rust were counted. Each bur was weighted before and after the experiment. The burs were photographed after the experiment using an optical microscope and a digital camera. The results showed that the second method proved to be the most effective method with no signs of rust, on any dental burs. On the contrary, 84.0% of those burs kept in the zero vacuum package and 70.0% of those kept in the drawer showed signs of rust. When compared the weight of bur before and after the experiment, the weight of dental burs kept in a zero vacuum package was significantly reduced (p \< .01) but there were no significant change in weight of the burs kept under the other two methods. In conclusion, the most effective way to keep dental long steel burs rust-free is storing in a sealed bottle containing silica gel.