In the present study the light transmitting capacity of differently shapedglass-fibre posts were estimated using visible light with a wavelengths of400-470 nm. The factory-made root canal posts' energy transmission wasevaluated in a preliminary exclusion procedure analysing their translucencyas well as in a following examination verifying their hardness. In theexclusion procedure, 3 different types of pins ( FRC Postec®, Twin LuscentAnchors® and ParaPost® FIBER WHITE) were illuminated in the darkroom.Pictures were taken of both the pin and of the emitted cloud of light. FRCPostec® and Twin Luscent Anchors® showed differences in light energydistributions whereas ParaPost® FIBER WHITE was found to have a limitedability of light transmission. In the following examination the rate ofpolymerization which depends on the light transferred through the pin, wasevaluated by estimating the hardness of dental cement (Knoop). 10 pins ofFRC Postec® and Twin Luscent Anchors® were fixed to the equipment with lightinduced polymerising composit Tetric®, illuminated for four differentexposure times and prepared as grinding compounds in order to measure thehardness of the surrounding dental cement. Assuming 25,8 KHM ± SD to bethe clinically acceptable hardness, Twin Luscent Anchors® showed a depth ofpolymerization of about 7.8 mm, FRC Postec® of 8.0 mm. Glass-fibrereinforced root canal posts revealed that light transmission depends on theindividual geometrical shape of the pin. Considering the size and the littledifferences in shape associated with it, the geometrical shape of the pointhas only a slightly distinctive impact on the light transmission.Consequence of which is a difference in degree of the dental cements'polymerisation. Palabras clave: glass-fiber post, capability of transmitting light, translucsnsy, light polymerisation