Evaluation of Oral Hygiene Products in an In Situ Caries Model

Inclusion Criteria: 1. Aged between 18 and 85 years inclusive 2. Understands and is willing, able and likely to comply with all study procedures and restrictions 3. Good general and mental health with, in the opinion of the investigator or medically qualified designee: * No clinically significant and relevant abnormalities in medical history or upon oral examination. * Absence of any condition that could affect the participant's safety or well-being or their ability to understand and follow study procedures and requirements 4. Currently living in the Indianapolis, Indiana area and has not had a professional fluoride treatment within 14 days of the first treatment visit 5. Currently wearing a removable mandibular partial denture with sufficient room in one posterior buccal flange areas to accommodate two enamel specimens 6. Willing to have their denture modified to accommodate enamel test specimens and willing and capable of wearing their removable mandibular partial dentures 24 hours per day during the experimental periods 7. Have a salivary flow rate in the range of normal values (un-stimulated whole saliva flow rate ≥ 0.2 milliliter (mL)/minute; gum base stimulated whole saliva flow rate ≥ 0.8 mL/minute). Exclusion Criteria: 1. Pregnant or breast feeding women 2. Known or suspected intolerance or hypersensitivity to the study materials (or closely related compounds) or any of their stated ingredients 3. Currently taking antibiotics or have taken antibiotics in the two weeks prior to the screening visit. 4. Taking or have taken a bisphosphonate drug for treatment of osteoporosis. 5. Participation in another GSKCH investigational dental product study within seven days of first study treatment. 6. Previous participation in this study. 7. Recent history (within the last year) of alcohol or other substance abuse.