Amalgam dental fillings and hearing loss

Area of Science:

• Audiology
• Dental Materials Science
• Environmental Health

Background:

• Dental amalgam, a common filling material, contains mercury.
• Potential health effects of dental materials are a growing concern.
• Hearing loss, particularly age-related hearing loss (presbycusis), affects a significant portion of the population.

Purpose of the Study:

• To investigate the relationship between dental amalgam exposure and auditory thresholds.
• To determine if the quantity or surface area of amalgam fillings impacts hearing.
• To explore potential links between amalgam fillings and age-related hearing decline.

Main Methods:

• Auditory thresholds were measured in 39 non-smoking women aged 40-45 across a frequency range of 0.25 to 16 kHz.
• Regression and correlation analyses were used to assess the association between hearing and dental filling data (amalgam vs. composite).
• American Speech-Language-Hearing Association (ASHA) criteria for ototoxic change were used as a reference.

Main Results:

• No significant correlation was found between composite fillings or drilling and auditory thresholds.
• A significant positive linear correlation was observed between amalgam filling data and auditory thresholds at high frequencies (8-16 kHz).
• The strongest association was at 14 kHz, with each additional amalgam filling linked to a 2.4 dB decline in hearing threshold.

Conclusions:

• The findings suggest an association between a higher number of amalgam fillings and poorer hearing thresholds at higher frequencies.
• This association may contribute to the development of presbycusis.
• The results support phasing out dental amalgams where suitable alternatives exist.