The long‐term effect of a zinc acetate and chlorhexidine diacetate containing mouth rinse on intra‐oral halitosis—A randomized clinical trial

Aim To evaluate the long‐term effects of a zinc acetate and chlorhexidine diacetate mouth rinse (Zn/ CHX ) on intra‐oral halitosis. Materials and methods Forty‐six adults with intra‐oral halitosis were randomized into a 6‐month, double‐blind, placebo‐controlled clinical study. The presence of intra‐oral halitosis was evaluated at baseline, 3 and 6 months after treatment by assessment of organoleptic score ( OLS ) and by total volatile sulphur compounds (T‐ VSC ), hydrogen sulphide (H 2 S) and methyl mercaptan ( MM ) concentrations in exhaled air. Results A Zn/ CHX mouth rinse provided significantly better control of intra‐oral halitosis than a placebo mouth rinse. At 3 and 6 months, individuals rinsing with the Zn/ CHX rinse presented with reductions of the OLS , T‐ VSC ( p  <   .01, respectively), H 2 S ( p  <   .001), and MM ( p  <   .01) in subjects’ exhaled air. At 6 months, 68.2% of individuals using the Zn/ CHX rinse experienced a 1 or 2 category improvement in OLS compared with 19.1% of placebo‐treated subjects. 91% of subjects in the Zn/ CHX group were categorized as being effectively treated for intra‐oral halitosis (i.e. H 2 S < 112 ppb), compared to 43% in the placebo group. Conclusion Zn/ CHX mouth rinse provides effective long‐term efficacy against intra‐oral halitosis, assessed both objectively and subjectively. With regular rinsing, the effect was sustained for 6 months.