The effects of brushing with three different dentifrices on plaque accumulation and gingival inflammation were studied in 83 subjects. The Turesky modification of the Quigley-Hein plaque index and a modified Löe-Silness gingivitis index were employed. Index scores were obtained in a randomized, double-blind study design, at 0 (baseline), 3-, 6-, and 9-week intervals. ANOVA analyses of results showed no significant differences between any of the three dentifrices used with respect to observed effects. Of interest, however, was the observation that with all three dentifrices reductions in plaque accumulations occurred, at 1% and 5% significance levels, without a corresponding commensurate improvement in the inflammatory status of the associated gingivae (using paired sample t-test analyses). The above results and relevant literature are discussed in support of the thesis that at times, for reasons as yet inexplicable, plaque and gingival inflammation may not be causally related in the manner so commonly observed.