Structural changes of the human saliva chemical composition at wearers of orthodontic appliances

Abstract

Our experiment focused on identifying the elemental chemical composition of salivary crystals' surface, obtained from patients with/without orthodontic appliances or metal-ceramic crowns in order to test their influence on human saliva. We used 110 samples of saliva derived from 19 patients (11 males and 8 females), with ages between 11–26 years old, divided into three groups: the control sample (without orthodontic appliances/metal-ceramic crowns), the study sample A (with orthodontic appliances/physiognomic metal-ceramic crowns) and the study sample B (former patients with previous orthodontic appliances). The surface elemental chemical composition was observed through Scanning Electron Microscopy (SEM) and was analyzed by X-ray Energy Dispersive Spectroscopy (EDS). The statistical analysis was performed in SPSS 20.0. Metallic elements (Ni, Al, Zn) that do not derive from the chemical composition of human saliva were found on all the salivary crystals. There were found statistically significant differences for Ni between the study sample B and the control sample (p<0.05). Our study found changes in the surface elemental chemical composition of crystallized human saliva. Orthodontic appliances applied in the oral cavity are not the main source of metallic elements released in the saliva, which is probably due to other causes from the investigated subjects' environment.