The objective of this 6-month, double-blind, clinical study, conducted in harmony with American Dental Association (ADA) guidelines, was to evaluate the efficacy of a
dentifrice containing 2%
zinc citrate and 0.76%
sodium monofluorophosphate in a
silica base (
zinc citrate dentifrice) for the control of supragingival plaque and
gingivitis, compared to a control
dentifrice containing 0.76%
sodium monofluorophosphate in a
silica base (control
dentifrice). Adult men and women from the Atlanta, Georgia, area were entered in the study and stratified into two treatment groups, which were balanced for baseline Quigley-Hein Plaque Index scores and baseline Löe-Silness Gingival Index scores. Participants received an oral prophylaxis and were instructed to brush their teeth twice daily (morning and evening) for 1 minute with their assigned
dentifrice, using a soft-bristled toothbrush. Examinations for supragingival plaque and
gingivitis were conducted after 3 months and again after 6 months' use of the study
dentifrices. Ninety-nine participants complied with the protocol and completed the entire 6-month clinical study. At both the 3- and 6-month study examinations, the
zinc citrate dentifrice group exhibited statistically significant reductions in both plaque and
gingivitis compared to the control
dentifrice group, based on whole-mouth data. At the 6-month examination, the magnitude of these reductions met or exceeded 18% for both plaque and
gingivitis (25.3% for plaque; 18.8% for
gingivitis). The effect of the
zinc citrate dentifrice was most pronounced on the more severe manifestations of plaque and
gingivitis, indicating a statistically significant (50.2%) reduction in severe plaque and a statistically significant (66.7%) reduction in severe
gingivitis over the control
dentifrice after 6 months of use. Similar findings were observed for data obtained from proximal, lingual, and posterior sites. Among the sites that indicated a tendency toward high levels of plaque or
gingivitis based on the baseline scores, substantially fewer sites tended to continue to present such high levels at follow-up exams in the
zinc citrate dentifrice group than in the control
dentifrice group. Thus, in accordance with the 1986 guidelines published by the ADA and the 1994 revision published by the Task Force on Design and Analysis in Dental and Oral Research, the results of this study support the conclusion that a
dentifrice containing 2%
zinc citrate and 0.76%
sodium monofluorophosphate in a
silica base is clinically efficacious for the control of supragingival plaque and
gingivitis.