The Study On Radiation Property Of Photosensitizer And Diagnosis For Calculus

Photodynamic as a new method has been used in diagnoses and therapy of tumors and some non-cancerous disease. It has a lot of outstanding advantages, such as small-wound, low-toxicity and high-selectivity. But photodynamic therapy has two shortages: it is very difficult to approve a new photosensitive medication; there is no director for fluorescent diagnosis. Our research is around optical properties of photosensitizer and autofluorescent diagnoses. The purpose of our research is using clinical medicine as photosensitizer in order to avoid the approval of the novel medicine. Furthermore, autofluorescence is used for spectral diagnoses of calculus, which has the important meaning to effectively treat the periodontal disease.Making use of energy level transition theories we analyze the three level energy system of a photosensitive molecule to build up decay traces of every energy level particle population. Absorption and fluorescence spectra of rhodamine123 and the influence of PH value were investigated. Time-resolved fluorescence spectroscopic measurements of rhodamine123 were carried out. The result indicates the lifetime of rhodamine123 is less than 1ns. The equipment of measuring singlet molecule oxygen produced by photosensitization was developed. The emission spectra from singlet molecule oxygen in the excited state photosensitized by rhodamine123 were not obtained on the equipment. This illustrates the product photosensitized by rhodamine123 is not singlet molecule oxygen, but free radical.A diagnose system was set up, then autofluorescence and sensitization fluorescence of calculus were measured. The measurement result indicates that no change was found between normal and calculus at 499nm, but two significant fluoresence peaks at 635nm and 690nm were found on the calculus. So autofluorescence can be used for spectral diagnoses of calculus.A great deal of research indicates rhodamine123 can selectively accumulate in the calculus, so fluorescence spectra of rhodamine123 can be used for photodynamic diagnoses of calculus. In conclusion, the ratio P<1 indicate no calculus, P>1 indicate calculus. Therefore, the present study will be benefic for...