DEMONSTRATIONS OF DEMINERALIZATION AND REMINERALIZATION MECHANISM AS REVEALED IN SYNTHETIC AUDITORY OSSICLE (APACERAM(R)) OF RATS BY LASER-RAMAN SPECTROMETRY

In investigations of the process of bone destruction caused by chronic otitis media complicated with cholesteatoma, we proposed previously a hypothesis to explain its mechanism. In the present study, we substit ute a synthetic auditory ossicle (Apaceram(R)) for the bone to simplif y the model system of experiments for our hypothesis. Its process was studied on a model simulation in vitro, in vivo and clinically at mole cular level, using laser-Raman spectrometry. An increase of conductivi ty in both the saline solution and double-distilled water immersed Apa ceram indicated demineralization depending on time lapse. The process of demineralization was revealed by the Raman spectral profiles as sho wn by narrowing a half-peak breadth (p<0.01) of v(1) signal PO43-, 960 cm(-1)) and the disappearance of the shoulder at circa 950 cm(-1) on the Apaceram surface implanted for 6 months. On the other hand, the pr ocess of remineralization was revealed in vivo by the spectral profile s: 1) a broader half-peak breadth (p<0.01) of v(1) signal on the Apace ram surface implanted for 10 months than that implanted for 6 months; 2) a weak reappearance of the shoulder at ca. 950 cm(-1) on the Apacer am surface after 10 months; 3) four signals (v(1) through v(4)) of PO4 3- on the HOAP observed for inside the Apaceram shaft and 4) a weak v( 1) signal on both the granular fluorescent substance in the clinical c ase and the high density area of subcutaneous tissue after contact wit h the Apaceram in rats for 3 months. Judging from these investigations , it is proposed that the mechanism of bone destruction associated wit h cholesteatoma is a form of de- and remineralization.