Noise rich in low frequency components, a new comorbidity for periodontal disease? An experimental study

Abstract

Introduction:Exposure to noise rich in low frequency components induces abnormal proliferation of extracellular matrix and collagens. The previous studies have shown alterations in the periodontium of both humans and animals. Our objective was the evaluation of collagens I, IV and V of the periodontium of Wistar rats exposed to noise rich in low frequency components.Materials and Methods:5 groups (each with 10 animals) were exposed to continuous low frequency noise (LFN). The LFN, from previously recorded white noise, frequency filtered and amplified, was applied in growing periods of 1, 3, 5, 9 and 13 weeks, in order to characterize the alterations with exposure time. A control group of ten animals was kept in silence. These animals were used in groups of 2 as aged-matched controls. After exposure, sections were obtained including teeth, alveolar bone and periodontium and observed after immunollabeling for collagens I, IV and V.Results:A significant increase in collagen I was observed in exposed groups (P < 0.001) (Kruskal-Wallis test). Post-hoc comparisons (Mann-Whitney test with Bonferroni correction) showed an increase in collagen I in animals exposed for 3 weeks or more (P < 0.001). The same test was applied to collagen V where significant differences were found when comparing control and exposed groups (P ≤ 0.004). The t-test for independent samples was applied to collagen type IV where no significant differences were found (P = 0.410), when comparing to the control group.Discussion:As in other organs, we can observe fibrosis and the newly formed collagen is likely to be “nonfunctional”, which could have clinical impact.Conclusion:Noise may constitute a new comorbidity for periodontal disease.

Industrial noise: A new stimulus for dental pulp aging? Qualitative and quantitative analysis in Wistar rat teeth–A pilot study

“…Most investigations focus on auditory effects; however, the effects of sound exposure can go beyond hearing loss [8,9]. The non-auditory effects of noise exposure can change the normal procedures of other organs and systems [10], including: degenerative cellular changes, stomach vascular injury [8], increased connective tissue in the liver [11], swelling of the renal glomerulus [12] fibrosis in the cardiac muscle [13], increased perivascular tissue of coronary arteries with significant periarterial fibrosis [14], induction of coronary perivascular fibrosis that differs under corticosteroid administration [15], increased in atrial interstitial fibrosis and a decreased in connexin 43 in rat hearts [16], increased risk of hypertension [17], increased in myocardial infarction and strokes [18] and changes in the adrenal cortex [19]. In the oral cavity, the authors described a morphological and functional change in the parotid gland [6], periodontal injury [20], and dental wear [21,22].…”