The optical characteristics of 39 excised human tumors are determined. Then liquid phantoms, representative of these tumors, are used to measure the space irradiance in a plane containing the optical axis for two irradiation geometries (external and interstitial) and two wavelengths (514 and 630 nm); a rotating miniature probe allows a spatial resolution of 0.1 mm. It is found that, on the optical axis, the space irradiance at the surface of a phantom is higher than the irradiance applied externally and exhibits a maximum prior to reaching an exponential decrease. A zone where green light is expected to provide better photochemical efficiency than red light is determined and the space irradiance obtained with external and interstitial irradiation are compared quantitatively. The clinical usefulness of the results is limited by the fact that individual samples belonging to the same type of tumor differ considerably in their optical characteristics, at least unless a more detailed classification (based on a greater number of tumor samples) is available.

Digestive System Neoplasms↗

PubMedDate not supplied

[New technic of surgical treatment of periapical lesions using carbon dioxide laser].

After briefly reviewing the use of the CO2 laser in dentistry, the authors will describe the materials and method for laser radiation after peri-apical surgery. The laser application will result in the sterilization of the apical region. The authors explain the importance of the "LASER-MIRROR" a mini contra-angle head which can maintain the integrity of the apex or minimize apical ressection while reflecting the laser beam at a 90 degree angle. Two case reports will be described and the authors will give the indications and contra-indications of their technic.

Aged↗

PubMedDate not supplied

[Experiences with PVC-dowel pins in the full crown technic].

Explore the source record for details and available documents.

Crowns↗