Sustainable oral healthcare: what is it and how do we achieve it?

In recent years, there has been an increase in interest in what environmental sustainability means for healthcare, including oral health and dentistry. To help facilitate discussions among key stakeholders in this area, the Scottish Dental Clinical Effectiveness Programme held a workshop in November 2022. The purpose of this workshop was to explore current thinking on the subject of sustainability as it relates to oral health and to help stakeholders identify how to engage with the sustainability agenda. This paper presents an overview of the presentations and discussions from the workshop and highlights potential avenues for future work and collaboration.

Phenothiazinium photosensitisers XI. Improved toluidine blue photoantimicrobials.

The phenothiazinium derivative toluidine blue O (TBO) is widely employed as a photoantimicrobial agent in clinical trialling, particularly in dentistry. However, its activity against a range of pathogenic microbial species is not significantly different to that of the standard photoantimicrobial methylene blue. In the current study, derivatives of TBO with varying hydrocarbon substitution in chromophore position 2 were synthesised via the established anilinethiosulphonic route, using the mild oxidant silver(II) carbonate to allow substituent preservation. The resulting series of analogues demonstrated the expected increases in visible absorption wavelength and lipophilicity with increasing hydrocarbon content, as well as decreased aggregation for derivatives with bulkier substituents, and all produced singlet oxygen on illumination in vitro. Screening against a range of bacterial and fungal pathogens relevant to infection control showed remarkable increases in activity relative to the parent compound, particularly against the clinically important Gram-negative bacterium Pseudomonas aeruginosa. In addition, in order to demonstrate clinical relevance, the photoactivities of the new derivatives against microbial targets were compared to conventional antibacterial and antifungal drugs, as well as biocides commonly used for local disinfection. Activity here was also generally greater than that of the conventional agents used for comparison, considerably so relative to the local disinfectant agents.