Extension of the working time of dental composites due to a new type of white operating lamp

Objectives: Dental composite materials for filling teeth are usually hardened by polymerisation lamps emitting blue light. However, the same wavelength is also emitted by light of dental operating lamps for lighting the oral cavity. Thus, the hardening of the composite is already initiated earlier, shortening the time of formability. The objective of this study is to develop a specific white LED for dental operating lamps. When restoring teeth, it enables dentists to work longer on light-curing composites in the same brightness.

Methods: Based on a short-wave blue coloured LED and a fluorescent substance, a white luminescent LED with a colour temperature of approx. 3,000 K is produced as a prototype. The formable working times of three composites are measured for this LED and two dental head lamps at an illuminance of 10,000 lx.

Results: Shorter working times of 98-237 s were measured for the headlamps and 409-807 s for the new LED. This light of the new LED is perceived by the human eye as warm white.

Conclusions: The new LED extends the working time by the factor of 3.0 to 5.8 compared to the head lamps. This enables more precise modelling of fillings.