Method for Extending the Handling Time of Composites

While setting a composite filling, the modelling of the light-sensitive filling material must be completed before the polymerisation of the composite begins. Generally, there is a risk of premature hardening caused by the light emitted from the lighting on the dentist's chair. Often, practitioners will attempt to limit the premature hardening by reducing the lighting through dimming or turning away the lamp to avoid triggering the polymerisation. Concentrated work under unfavourable lighting conditions puts strain on the eyes of the practitioner, leading to accelerated fatigue. The aim of this study is to show that the use of filters on the dentist chair lamps allows for sufficient lighting in the oral cavity with no detrimental effects on the modelling of the composite, thus eliminating unnecessary stressful working conditions. The filters selected and presented here provide sufficient lighting, providing 80 % of the normal intensity while extending the time frame for molding by a factor up to 48. In principle, existing lighting can easily be retrofitted with such filters at minimal cost.