Relationship between 1-, 3-, and 6-Month Gingival Bleeding Outcomes.

Introduction: Results from systematic reviews and meta-analyses show generally consistent antigingivitis effects between 3- and 6-mo observation time points with twice-daily use of stannous fluoride (SnF₂) dentifrice. However, the relationship between 1-, 3-, and 6-mo gingivitis responses has not been investigated.

Methods: This pooled analysis was conducted to understand the relationship of 1-, 3-, and 6-mo gingival bleeding outcomes. Number of bleeding sites, derived from Löe-Silness Gingival Index (LSGI) or Gingival Bleeding Index, was identified as the primary end point of the analysis for the biological and clinical relevance. Randomized, double-blinded, controlled clinical studies meeting the following predefined selection criteria were identified: 1) published and unpublished gingivitis clinical trials conducted from 1995 to 2022 comparing efficacy of 0.454% SnF₂ dentifrices to negative controls (sodium fluoride or sodium monofluorophosphate dentifrice) and 2) studies with a 3-mo assessment and at least a 1- or 6-mo assessment.

Results: The search resulted in ten 6-mo and fourteen 3-mo studies meeting selection criteria. A mixed-effects model was performed on the pooled data to assess gingival bleeding outcomes across time. The bleeding efficacy significantly increased between months 1 and 3 (P < 0.0001) and plateaued between months 3 and 6 (P = 0.007), supporting the fact that bleeding reduction relative to control established by 1 mo will increase and be maintained through 3 and 6 mo (R² = 0.857). In addition, gingival bleeding and gingivitis efficacy, as measured by LSGI, were found to be highly correlated (R² = 0.874).

Conclusion: A clear relationship has been demonstrated between 1-, 3-, and 6-mo gingival bleeding outcomes in gingivitis clinical studies comparing SnF₂ dentifrice to negative control dentifrice. These findings have important implications to the dental practice and scientific research as antigingivitis efficacy evaluations can be observed as early as 1 mo and are consistent with those seen at 3 or 6 mo.

Knowledge transfer statement: Outcomes from this investigation indicate that the clinical evaluation of antigingivitis efficacy at 1 mo is predictive of that at 3 and 6 mo, supporting studies of 1-mo duration as a viable method of knowledge acquisition. This more efficient, expedited research design has positive implications for patient care, clinical practice guidelines, protocols, and policies.