S2k guideline: Laser therapy of the skin.

This guideline aims to improve the efficiency and safety of lasers and optical radiation sources with similar effects (especially IPL). Laser therapy of skin lesions with an increased amount of melanocytes should be performed with caution. Laser treatment of pigmented melanocytic nevi is not recommended. The guideline contains recommendations regarding the treatment of lentigines and café-au-lait spots, non-pigmented dermal nevi, Becker nevus, nevus of Ota/Hori/Ito and melasma. Further recommendations focus on the treatment of skin lesions without an increased amount of melanocytes (ephelides, postinflammatory hyperpigmentation including berloque dermatitis, seborrheic keratoses, traumatic/decorative tattoos and metallic deposits), hypopigmentation (vitiligo), benign non-pigmented neoplasms (fibrous papule of the nose, nevus sebaceus, epidermal nevus, neurofibroma, sebaceous gland hyperplasia, syringoma, xanthelasma palpebrarum), inflammatory dermatoses (acne papulopustulosa/conglobata, acne inversa, granuloma faciale, lichen sclerosus, lupus erythematosus, psoriasis vulgaris, rosacea, rhinophyma), wrinkles/dermatochalasis/striae, hypertrichosis, scars (atrophic, hypertrophic; keloids, burn/scald scars), laser-assisted skin healing, onychomycosis, precancerous lesions and malignant tumors (actinic keratoses/field cancerization, cheilitis actinica, basal cell carcinoma), vascular skin lesions (angiokeratoma, angioma, hemangioma, malformation, spider veins, granuloma telangiectaticum (pyogenic granuloma), rubeosis (erythrosis interfollicularis colli, ulerythema ophryogenes), nevus flammeus, telangiectasias and Osler's disease (hereditary hemorrhagic telangiectasia) and viral skin lesions (condylomata acuminata, mollusca contagiosa, verrucae planae juveniles/vulgares/ verrucae palmares et plantares).

Perturbation factors in the clinical handling of a fiber-coupled Raman probe for cutaneous in vivo diagnostic Raman spectroscopy.

The application of fiber-coupled Raman probes for the discrimination of cancerous and normal skin has the advantage of a non-invasive in vivo application, easy clinical handling, and access to the majority of body sites, which would otherwise be limited by stationary Raman microscopes. Nevertheless, including optical fibers and miniaturizing optical components, as well as measuring in vivo, involves the sensibility to external perturbation factors that could introduce artifacts to the acquired Raman spectra and thereby potentially reduce classification performance. In this study, typical perturbation factors of Raman measurements with a Raman fiber probe, optimized for clinical in vivo discrimination of skin cancer, were investigated experimentally. Measurements were performed under standardized conditions in clinical settings in vivo on human skin, as well as ex vivo on porcine ears. Raman spectra were analyzed in the fingerprint region between 1150 and 1730 cm(-1) using principal component analysis. The largest artifacts in the Raman spectra were found in measurements performed under the influence of strong ambient light conditions as well as after miscellaneous pre-treatments to the skin, such as use of a permanent marker or a sunscreen. Minor influences were also found in measurements using H2O immersion and when varying the probe contact force. The effect of reasonable variation of the fiber-bending radius was found to be of negligible impact. The influence of measurements on hairy or sun-exposed body sites, as well as inter-subject variation, was also investigated. The presented results may serve as a guide to avoid negative effects during the process of data acquisition and so avoid misclassification in tumor discrimination.

Simulation of color perception of layered dental composites using optical properties to evaluate the benefit of esthetic layer preparation technique.

OBJECTIVES: Esthetic restorations require that dental restorative materials have similar optical properties to teeth. To improve the color perception, the inhomogeneous morphology of the native tooth can be imitated by layering two optically different restorative materials. However until now the benefit of this method has not been satisfactorily demonstrated. METHODS: The optical parameters, absorption coefficient µ(a), scattering coefficient µ(s), anisotropy factor g and effective scattering coefficient µ'(s), were determined for the enamel and dentin material of the restorative material systems Artemis(®) and Herculite XRV(®). This was carried out for each material system in the wavelength range between 400 and 700nm using integrating sphere measurements followed by inverse Monte Carlo simulations. RESULTS: Using the optical parameters and a forward Monte Carlo simulation, the color perception of layered samples could be predicted with a sufficient degree of accuracy. The total color impression was shown to be dependent on the sample thickness and the transparency/translucency of the single layers of enamel and dentin materials. CONCLUSION: The study demonstrated that the use of two materials is well-suited for the restoration of front teeth with their relatively high proportion of enamel. This study will continue further with the compilation of a data pool of optical parameters which will enable the application of calculation models to optimize the optical approximation of the natural tooth.

Optical properties of dental restorative materials in the wavelength range 400 to 700 nm for the simulation of color perception.

Aesthetic restorations require dental restorative materials to have optical properties very similar to those of the teeth. A method is developed to this end to determine the optical parameters absorption coefficient mu(a), scattering coefficient mu(s), anisotropy factor g, and effective scattering coefficient mu(s) (') of dental restorative materials. The method includes sample preparation and measurements of transmittance and reflectance in an integrating sphere spectrometer followed by inverse Monte Carlo simulations. Using this method the intrinsic optical parameters are determined for shade B2 of the light-activated composites TPH((R)) Spectrum, Esthet-X, and the Ormocer Definite in the wavelength range 400 to 700 nm. By using the determined parameters mu(a), mu(s), and g together with an appropriate phase function, the reflectance of samples with 1-mm layer thickness and shade B2 could be predicted with a very high degree of accuracy using a forward Monte Carlo simulation. The color perception was calculated from the simulated reflectance according to the CIELAB system. We initiate the compilation of a data pool of optical parameters that in the future will enable calculation models to be used as a basis for optimization of the optical approximation of the natural tooth, and the composition of new materials and their production process.