Differentiation of the Anti-plaque Efficacy of Oral Hygiene Agents

Objectives: This investigation evaluated the effects of Colgate Total (CT), Crest Pro-Health (CPH); sodium lauryl sulphate (SLS), triclosan (TCS), stannous fluoride (SF), zinc lactate (ZL) and ZLSF in combination on the microbial ecology of oral microcosms maintained in modified drip flow biofilm reactors (MDFRs) and hydroxyapatite disc bioreactors (HDBs). Methods: Fresh saliva was used to inoculate the MDFRs and HDBs. Antimicrobial agents were delivered to the MDFRs 4 times daily for 6 days and to the HDB once. Viable counts, gravimetric analysis and denaturing gradient gel electrophoresis (DGGE) were used to determine the antimicrobial effects. Results: Following multiple treatment periods, TCS was significantly more effective than ZLSF at reducing biomass (>95% at 6d) and ZLSF was significantly more effective than either ZL or SF at reducing the amounts of all functional bacterial groups. TCS significantly (P<0.05) targeted all groups monitored whilst ZLSF also caused significant (P<0.05) reductions in total anaerobes and streptococci. SF was the least effective agent tested. DGGE analysis revealed that TCS was the most effective individual compound tested; causing marked reductions in diversity on DGGE gels. HDB experiments revealed that only TCS, SLS and CT had significant broad-spectrum activity. ZL and SF alone and in combination did not cause any significant reduction in bacterial viability. Conclusions: Data demonstrate the broad-spectrum efficacy of CT and TCS against dental plaque in comparison to CPH and ZLSF.