Tenuta, Livia MAlmalki, Jawharah2024-10-062024Effect of Dextranase on S. mutans Biofilm. Almalki J, Capalbo LC, Yoshino N, Tenuta LMA’https://orcid.org/0009-0001-7790-6842https://hdl.handle.net/20.500.14154/73162Dental biofilms are complex structures that are influenced by their environments. Dysbiosis of these biofilms can cause diseases, with dental caries being the most prevalent biofilm-mediated disease. This dissertation investigates the composition of biofilms, their role in dental caries, and the concept of biofilm alteration and modification by the use of enzymatic treatments. A special focus is given to the extracellular polysaccharides in the dental biofilm matrix, which are formed upon exposure to sucrose. In a review manuscript, we discuss the existing knowledge of biofilm modification with an extensive review of the literature. Over the last decades, different enzymes have been used in an attempt to modify the biofilm matrix and make it more susceptible to anticaries treatments. Dextranase, mutanase, and eDNAse are example of enzymes which show promising results for continuing investigation. Then, we experimentally tested in vitro the effect of short (1 min) treatments, twice/day, on the composition of cariogenic Streptococcus mutans biofilms grown in the presence of sucrose. Dextranase at 2 and 20 units/mL were able to significantly reduce biofilm biomass; the proportion of extracellular polysaccharides to total biofilm mass was not significantly different between treatments with or without dextranase. In conclusion, enzymes that modify the biofilm matrix can be adjunct agents in anticaries treatments; for example, the use of dextranase was shown to reduce S. mutans biofilm mass and potentially its cariogenicity.51enBiofilmDental BiofilmDextranaseThesis