UV light-embrittled dental resin cement containing photodegradable polyrotaxane cross-linkers. (IMAGE) Tokyo Medical and Dental University Caption To facilitate the debonding of dental restorative materials adhered on tooth surfaces, UV light-embrittled dental resin cement containing photodegradable polyrotacane (PRX) cross-linkers was developed. PRX is a supramolecular interlocked polymer composed of α-cyclodextrin threaded on a linear polymer chain capped with bulky stopper molecules. The photodegradable PRXs containing photolabile o-nitrobenzyl ester was newly designed and used as a cross-linker of dental resin cements. The UV irradiation cleaves o-nitrobenzyl ester and the PRXs are dissociated, leading to decreasing the adhesive force of the dental resin cements. The plastic block was adhered on to the surface of bovine dentin using adhesive resin cement cross-linked with photodegradable PRXs, and the adhesive strength between plastic and dentin was clinically acceptable value. By contrast, the adhesive force was decreased by approximately 60% through the irradiation of UV light for 2 min, due to the photodegradation of PRX cross-linkers. This result suggests that the adhesive resin cement containing photodegradable PRX cross-linkers is a promising candidate for facilitating the debonding of dental materials from tooth surfaces via UV light irradiation. Credit Department of Organic Biomaterials,TMDU Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.