| 摘要 |
<p>The studies made on Dental units revealed that the single light head device used in the classical system is inadequate. The reflector device with double light heads provides light without shadows and thus ensures a larger illumination area, stronger illumination and where necessary, illumination of two separate parts either within the mouth and outside of the mouth, and because it has two distinct sources of light which can be directed independently, the treatment will not be hampered even if one of the reflectors is out of order for any reason.</p> |
