A randomised clinical trial to assess maintenance of gingival health by a novel gel to foam dentifrice containing 0.1%w⁄w o-cymen-5-ol, 0.6%w⁄w zinc chloride Objectives: To assess the ability of 0.1%w ⁄ w o-cymen-5-ol ⁄ 0.6%w ⁄ w zinc chloride gel to foam dentifrice to maintain gingival health compared to a sodium fluoride control dentifrice. Design: Following a baseline examination, subjects went through a regimen to bring them to a high level of gingival health. This involved a professional dental prophylaxis supported by oral hygiene instruction prior to commencing study treatment. Subjects brushed twice daily for 12 weeks with either the test or control dentifrice. Examinations for gingival inflammation (MGI), bleeding and plaque were performed after 12 weeks. Results: 205 subjects were included in the efficacy analysis. Relative to the sodium fluoride ⁄ silica control dentifrice group the o-cymen-5-ol ⁄ zinc chloride gel to foam dentifrice exhibited statistically significant reductions (p < 0.0001) in MGI, bleeding and plaque of 32.2%, 26.3% and 20.7% respectively after 12 weeks. Conclusion: The results of the present clinical study demonstrate that the use of the 0.1%w ⁄ w o-cymen-5-ol ⁄ 0.6%w ⁄ w zinc chloride gel to foam dentifrice over a 12 week period provides a statistically significant benefit in maintaining gingival health compared to a sodium fluoride control dentifrice.