Date of Award


Degree Type


Degree Name

Master of Clinical Dentistry




Dr. Peter Cadieux


An Evaluation of Novel Approaches to Antimicrobial Control of Oral Biofilms

Introduction: Streptococcus mutans (SM) and Haemophilus actinomycetemcomitans (HA) are important pathogens in the development of caries and periodontitis. This thesis investigated several novel strategies aimed at preventing their growth and biofilm forming capacity.

Methods: SM and HA biofilms were challenged with numerous antimicrobial solutions and assessed for biofilm retention and bacterial survival. Antibiotic susceptibility profiling was performed and the ability of antimicrobial-impregnated silicone disks and Streptococcus salivarius probiotic strains K12 and M18 to inhibit the pathogens was investigated.

Results: Silicone oil effectively disrupted HA biofilms but did not affect either pathogen’s viability. Neither HA nor SM showed any relevant antibiotic resistance and polyvinyl siloxane impregnated with triclosan and chlorhexidine demonstrated antibacterial activity against both strains. Finally, both probiotics inhibited the growth of HA but not SM via differential antagonism.

Conclusions: This work supports the widening application of silicone- based products and probiotics in maintaining oral health and fighting disease



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