The aim of this study is to evaluate the effect of a toothpaste containing stannous fluoride (SnF2) over time on the oral bacterial composition and activity and to explore its effect in comparison to a regular fluoride toothpaste.

This will be a single-center, 6-week, randomized, controlled, analyst and examiner-blind, two treatment, parallel group design, methodology development clinical study, investigating the efficacy of a toothpaste containing 0.454 percent (%) SnF2 in healthy adult participants with mild-moderate gingivitis. The study will describe and compare the overall oral bacterial composition and activity following 6 weeks use of a 0.454 % SnF2 toothpaste and regular fluoride toothpaste (control) using microbial and functional profiling techniques. Participants will be instructed to brush twice daily (morning and evening) in their usual manner, for 1-timed minute, for 6 weeks and to record each brushing in the diary provided. Sufficient participants will be screened to ensure approximately 50 participants complete the entire study.

Inclusion Criteria:

• Participant provision of a signed and dated informed consent document indicating that the participant has been informed of all pertinent aspects of the study before any assessment is performed.
• Participant is male or female who, at the time of screening, is aged 18-65 years, inclusive.
• Participant who is willing and able to comply with scheduled visits, sampling schedule, treatment plan and other study procedures.
• Participant, in the opinion of the investigator or medically qualified designee, in good general and mental health.

At Screening (Visit 1):

• Participant with at least 20 natural, permanent teeth (excluding 3rd molars).
• Participant with at least 40 evaluable surfaces.
• Overall mean Turesky Modified Quigley and Hein Plaque Index (TPI) score greater than or equal to (>=) 1.5.
• Participants with 10% less than (<) bleeding sites (BS) < 30%

Exclusion Criteria:

• A participant who is an employee of the investigational site, either directly involved in the conduct of the study or otherwise supervised by the investigator, or a member of their immediate family; or a sponsor employee directly involved in the conduct of the study or a member of their immediate family.

• A participant who has participated in other studies (including non-medicinal studies) involving investigational product(s) in the 30 days prior to study entry and/or who is participating in other studies during study participation.

• A participant with, in the opinion of the investigator or medically qualified designee, an acute or chronic medical or psychiatric condition or laboratory abnormality that may increase the risk associated with study participation or investigational product administration or may interfere with the interpretation of study results and, in the judgment of the investigator or medically qualified designee, would make the participant inappropriate for entry into this study.

• A participant with any medical/oral condition which, in the opinion of the investigator or medically qualified designee, could impact study outcomes (for example, oral dryness or could directly influence gingival bleeding).

• A participant taking daily doses of medication/having daily treatments which, in the opinion of the investigator or medically qualified designee, could impact study outcomes (for example, is causing oral dryness).

• A participant who is pregnant (self-reported; no pregnancy test required) or intending to become pregnant over the course of the study.

• A participant who is breastfeeding.

• A participant with known or suspected intolerance or hypersensitivity to the study materials (or closely related compounds) or any of their stated ingredients.

• A participant who is unwilling or unable to comply with the Lifestyle Considerations described in this protocol.

• A participant who has difficulty complying with study procedures and examinations, such as excessive gagging during oral assessments.

• A participant who has had routine dental prophylaxis within 12 weeks of Screening.

• A participant who has undergone a tooth bleaching procedure (at-home or professional) within 8 weeks of Screening.

• A participant with any of the following which, in the opinion of the investigator or medically qualified designee, could impact study outcomes or the oral health of the participants if they were to participate in the study:

  1. Severe gingivitis.
  2. Signs of active periodontal disease or who is receiving or has received treatment for periodontal disease (including surgery) within 12 months of Screening.
  3. Active caries.
  4. Evidence of gross intra-oral neglect or the need for extensive dental therapy.
  5. Restorations in a poor state of repair or metal fillings.
  6. Any dental condition (example, malalignment, overcrowding)
  7. High levels of extrinsic dental stain or calculus deposits.

• A participant with the following:

  1. A tongue or lip piercing.
  2. Multiple dental implants which, in the opinion of the investigator or medically qualified designee, could impact study outcomes.
  3. Fixed bridge(s) or removable partial dentures.
  4. Has or has had fixed or removable orthodontic braces/bands or a fixed orthodontic retainer within 3 months of Screening.

• A participant who is unwilling to forgo use of an orthodontic retainer for the duration of the study, provided there would be no impact on the outcome of any previous, completed orthodontic treatment or the participant's well-being.

• Participant who is a current smoker or an ex-smoker who stopped within 6 months of Screening (Visit 1).

• Participant who is a currently user of recreational drugs (example, cannabis) within 6 months of Screening.

• Participant who currently uses smokeless forms of tobacco (example, chewing tobacco, nicotine-based e-cigarettes) within 6 months of Screening.

• Visit 1 (Screening)

  1. A participant who has taken antibiotics within 4 weeks of Screening.
  2. Participant who has used an anti-bacterial mouthwash (example, chlorhexidine) or another oral care product within 2 weeks of Screening that, in the opinion of the investigator or dentally qualified designee, could affect plaque formation or gingival health.

• Visit 2 (Baseline)

  1. A participant who has taken antibiotics during the lead-in period (between Screening and Baseline).

• Participant with a recent history (within the last year) of alcohol or other substance abuse.

• A participant who has previously been enrolled in this study.

• Participant who, in the opinion of the investigator or medically qualified designee, should not participate in the study.

Anonymized individual participant data and study documents can be requested for further research from ww.clinical-trial-register@haleon.com

IPD will be made available within 6 months of publishing the results of the primary endpoints, key secondary endpoints and safety data of the study.

Access is provided after a research proposal is submitted and has received approval from the Independent Review Panel and after a Data Sharing Agreement is in place. Access is provided for an initial period of 12 months, but an extension can be granted, when justified, for up to another 12 months.

Safety population included all randomized participants who completed at least one use of study product.

From signing of informed consent form until 5 days after last administration of study product or last study procedure (up to approximately 51 days)

An adverse event (AE) was defined as any untoward medical occurrence in a clinical study participant, temporally associated with the use of a study product including any washout or lead-in product (or medical device), whether or not considered related to the study product, including any washout or lead-in product (or medical device). A Serious Adverse Event (SAE) was a particular category of an AE where the adverse outcome is serious.