Invitro Evaluation of Antimicrobial Efficacy of a Liquid Denture Cleanser

Proper cleansing of dentures is an essential daily routine in order to ensure the safety and satisfaction of the edentulous patient.  Although mindful of the predominantly aesthetic benefits of cleansing (removal of stain, malodor, off-taste), consumers often overlook the antimicrobial benefit that is essential for the prevention of colonization that can lead to denture-related stomatitis and even systemic diseases.  While the antimicrobial efficacy of effervescent tablet cleansers is well established, many of these claims may be based on recommendations for overnight product usage.  In contrast, much less is understood about the antimicrobial efficacy of liquid cleansers designed to be manually applied by brushing on dentures typically for two minutes or less.  Objectives: In this study, we examined the antimicrobial efficacy of a liquid denture cleanser against five representative bacterial species using an in-vitro kinetic kill protocol.  Methods:  Inoculations of K. pneumoniae, F. nucleatum, V. atypica, A. viscosus, and S. sanguis were exposed to a liquid denture cleanser formulation (diluted 1:1 in artificial saliva & sterile tap water) for up to 120 seconds. At pre-determined time-points, aliquots were removed and reaction neutralized in broth.  Ten-fold serial dilutions (down to 10^-4) were then performed and bacterial populations were measured after 48-72 hour incubation.  Percent kill was determined using a calculation derived from ASTM E-1153.  Results:  K. pneumoniae, V. atypica, A. viscosus, and S. sanguis were reduced > 99.99% at 90 seconds and F. nucleatum was reduced by 99.99% at 90 seconds.  Conclusion:  Liquid denture cleansers are potentially an effective alternative to effervescent tablets for the control of common oral bacteria.  Significant reductions in bacterial load were observed within typical durations of consumer use.  Research supported by GlaxoSmithKline.