The aim of this study was to assess whether sodium hypochlorite (NaOCl) or chlorhexidine (CHX) and two irrigation protocols may alter the antibacterial properties of dentine and three endodontic sealers using a novel ex vivo tooth model.

Abstract from Håkon Valens lecture at symposium PDT-4. Human antimicrobial PDT. ESP-IUPB World Congress, Light & Life, Barcelona, Spain. August 25-30. 2019. Bacteria in the oral cavity lives primarily in polymicrobial biofilms. Oral mature biofilms may contain several hundred different bacterial species, and over 600 different species have been shown to colonize the oral cavity. […]

The increased occurrence of antibiotic resistance in general necessitates development of alternative antimicrobial drugs or methods. Further, certain cases of periodontitis respond poorly to conventional treatment. The principle of photodynamic therapy, currently used against certain cancers, may be a practical treatment modality for oral infections, presumably with low possibility for development of resistance. The treatment requires the presence of light-absorbing molecules (photosensitizer; PS) and irradiation with a light source emission that spectrally matches the light-absorption of the PS.