| 摘要 |
<p>The invention refers to an orthochromatic system of rare earh elements screen film for intra-oral odontological radiology, which is characterized by comprising: 1.a) a protective layer (1-PL) b) one phosphor emulsion layer (1-PEL), comprised by fluorescent grains of phosphor and oxysulphite of gadolinium and terbium; c) an aborption or reflection layer (1-ARL); d) one base or support (1-BS) or 2.a) one protective layer (2-PL), comprised by a gelatin, an anti-static agent and a hardening agent; b) one emulsion layer (2-EL), comprised by silver halide gelatin "anti-fog"; also containing a sensitizing ink; c) one sub-layer or substrate (2-SS); d) one base or support (2-BS). That combination of a rare earth elements screen (1) and orthochromatic film (2) allows to reduce the time of exposure to X-rays between 0.05 and 0.13 of a second, measured by the ionization chamber that consequently provides an optimization of the restriction of the dosage og ionizing radiation between 10 and 15 times (an average of 0.12 mGy) for the patients and professionals that stand close to the source of radiation during the performance of the periapical and occlusive radiographs and also allows to reduce the time for manual development with an average of 8 seconds, for a developer temperature of approximately 23 DEG C to 25 DEG C.</p> |
