Pose, smile, click, and a selfie with a perfect smile and shiny white teeth has been taken that may go viral on social media. For those who resort to tooth whitening to enhance their smile, a bifunctional photodynamic dental therapy (PDDT) strategy newly developed by researchers in Tianjin may well meet their demands in a more convenient and efficient way.

Compared to traditional physical whitening treatments, like polishing and veneer coverage, that may cause irreversible damage to the enamel, chemical bleaching technology provides a safer alternative. It is based on the degradation of chromogen by reactive oxygen species (ROS) and can oxidize the colored chromogen caused by smoking or drinking beverages, turning it into colorless smaller compounds, and disintegrating the biofilm.

Synthetic route for ZMP and schematic illustration of using PDDT for tooth whitening and biofilm eradication.

The PDDT strategy is a kind of chemical bleaching technology that has been designed by Prof. Zhang Lei’s team at Tianjin University and Prof. Zhang Xu’s team from the Stomatological Hospital affiliated to Tianjin Medical University. They synthesized a highly water-soluble, biocompatible zwitterion-modified porphyrin (ZMP) and raised the reactive oxygen species output to be roughly 8 times higher.

According to Prof. Zhang Lei, this new strategy can not only whiten teeth harmlessly by degrading the chromogen, but also eradicate about 95% of the biofilm by disintegrating extracellular polymeric substances.