Our theoretical and experimental results prove massive beam-hardening artifacts for a typical implant diameter and typical energies of up-to-date CBCT machines. Meaningful artifact reduction has to be based on more sophisticated mathematical modeling of the actual physical image acquisition process rather than on postprocessing of the erroneous results obtained from the rather crude reconstruction algorithms used presently.

A cellular effect of the soft laser application is clearly discernible. Clinical studies are needed to evaluate whether the application of low-level laser therapy might be beneficial in regenerative periodontal therapy.

Even at low energy densities, the Er:YAG laser has a high bactericidal potential on common implant surfaces. Clinical studies are justified to evaluate the applicability and efficacy of the Er:YAG laser in the treatment of peri-implantitis.

A cellular effect of the soft laser irradiation on HGF is evident. Its duration, however, seems to be limited. These findings might be clinically relevant, indicating that repeated treatments are necessary to achieve a positive laser effect in clinical applications.

Background. Anatomic location has been identified by several investigators as a significant prognostic factor for patients with primary cutaneous melanoma (CM). However, the best determination of higher and lower risk sites is still controversial, and the biologic significance of tumor site in the course of primary CM is unknown. The aim of the present study was to identify higher and lower risk sites based on multivariate analysis. Methods. A series of 5093 patients with invasive primary cutaneous melanoma followed from 1970 to 1988 at four university centers in Germany was investigated using the multivariate Cox proportional hazard model to analyze the importance of anatomic location for survival probability. Results. The anatomic location was found to be a highly significant prognostic factor for patients with primary melanoma by multivariate analysis (P < 0.0001). An optimized classification into sites of higher and lower risk with respect to survival was evaluated by multivariate analysis controlling for the possible confounding effects of the other significant prognostic factors. Relative to the lower leg as the prognostically favorable baseline, the following locations were associated with a significantly higher risk of death caused by primary cutaneous melanoma: back and breast (thorax), upper arm, neck, and scalp (TANS regions). The lower trunk, thigh, lower leg, foot, lower arms, hands, and face were identified as lower risk sites. Conclusions. Anatomic location was confirmed as an independent prognostic factor for patients with primary cutaneous melanoma. The TANS regions were identified as high risk sites, and the lower trunk, thigh, lower leg, foot, lower arms, hands, and face were identified as intermediate sites.