Breathing While Asleep May Promote Tooth Decay
A study by dentistry researchers from the University of Otago, Dunedin, New Zealand, and published in the Journal of Oral Rehabilitation, has found that breathing through the mouth during sleep may promote dental erosion and decay.
Saliva helps the mouth to maintain proper PH levels and not become too acidic. Saliva can dry up for mouth breathers.
Researchers investigated what happens to acidity levels in the mouth during open- and closed-mouth sleep. They measured pH and temperature levels in the mouths of 10 healthy volunteers as they alternately slept with and without a nose clip that forced them to breathe through the mouth.
Ranging from 0-14, pH is a measure of acidity. A pH of 7 is neutral, a pH under 7 is acidic, and a pH above 7 is basic or alkaline.
On average, daytime mouth pH was 7.3, and during sleep it was 7.0. The mean mouth pH during sleep with mouth breathing was 6.6, "which was statistically significant compared with the normal sleep condition," according to the study authors.
At some stages during the night, pH levels inside the mouth dropped to 3.6 in individuals who breathed through their mouths. This is well below the threshold (pH 5.5) for when tooth enamel starts to break down.
Joanne Choi, a PhD student in the Faculty of Dentistry in the Sir John Walsh Research Institute at Otago, summed up the results: "This study is the first to continuously monitor intraoral pH changes in healthy individuals over several days. Our findings support the idea that mouth breathing may indeed be a causal factor for dental diseases such as enamel erosion and caries."