Influence of laser light on bioimplants used in otorhinolaryngology.

In otorhinolaryngology, dermatology and reconstructive surgery biomaterials as implants and a variety of lasers are used. Laser light applied near to an implant could have the risk to damage these materials. Therefore, their resistance exposed to laser light is of interest. A diode laser emitting at 940 nm and a CO2 laser were used to investigate its effects to the biomaterials Bioverit®, Medpor® and Palacos®, and in addition, an excised implant containing Medpor® and nasal turbinate tissue, excised and fixed in formalin. The macro- and microscopic changes of the material, temperature development during laser energy application in dependency to distance of fibre and material, time of exposure and applied power were investigated. Interaction of diode laser light with Bioverit® (0 mm distance, 360 s, 10 W, 3,600 J) resulted in minimal microscopic effects in direct contact of with the fibre. Using Medpor® (1 mm, 10s, 10 W, 100 J) resulted in melting and perforation. In the case of Palacos® (0.6 mm, 10s, 10 W, 100 J), melting occurred creating a flat excavation. The effect to Medpor® in nasal turbinate (1-2 mm, 10s, 10 W, 100 J) showed tissue denaturation and carbonisation and creation of a hole. The interaction of the CO2 laser with Bioverit® (3 cm, 0.5, 1 and 5 s, 2, 10 or 20 W) induced melting and discolouring resulting finally in a perforating hole. Depending on the material, first damage starts 10 s after an impact of 100 J (threshold value). So interaction between laser energy and biomaterials occurs. This should be carefully considered during clinical laser treatments especially nearby implants.