Optical Spectroscopy to Detect Changes in Rats Hard Tissues With Osteoporosis

Objectives: Osteoporosis is a systemic disease characterized by low bone mass and micro architectural deterioration of bone tissue which may be associated with oral disease. In this way, the aim of this study was to evaluate changes in tissue structures and mineral content of teeth and bone in rats with induced osteoporosis.
Methods: Ten female Wistar rats (n=10) were randomized into 2 Groups: Control Group (C) non and ovariectomized rats Group (OV). Ovariectomized rats induced osteoporosis. The optical spectroscopy and energy dispersive X-ray (EDX) of lower incisor teeth and femur bone was performed for long-term (6 months post-ovariectomy). Fluorescence spectra was obtained with diodo laser and a doubled-frequency of a Nd:YAG laser consecutively for excitation at 408 nm (violet) and 532 nm (green). Raman spectra was obtained with excitation laser at 785 nm. The atomic concentrations of phosphate (P) and calcium (Ca) were measured using EDX. One-way ANOVA and Tukey’s post-hoc test were performed using Statistica for Windows Release 7 software (Statsoft Inc., Tulsa, Ok) at a significance level of 5% (p<0.05).
Results: Changes in fluorescence spectra were observed with laser at 532 nm, showing a significant increase (p<0.05) of the band area in OV compared to C for teeth (80989±4512 vs. 97222±704) and bone (87431±5170 vs. 97070±2214). The phosphate/amide ratio was significantly greater (p<0.05) in OV than C for dentine (86±34 vs. 53±27) and cortical bone (2.04±0.86 vs. 1.29±0.25). The concentrations of P for dentine (11.15±0.09 vs 12.05±0.07) and Ca for cortical bone (20.91±0.58 vs. 22.73±0.72) were significantly reduced (p<0.05) in OV compared to C.
Conclusions: The aging process and osteoporosis may lead to alterations in mineral crystallites and reduced mineral content of teeth and bone. The optical spectroscopy may be used to evaluate quality of teeth and bone, allowing portability, rapid clinical assessment with low cost and preventing dental and orthopedic complications.