Conditions: Dental Caries
Allocation: RANDOMIZED | Intervention model: CROSSOVER
Enrollment: 58
Healthy volunteers: yes

Brief summary:
This will be a single-centre, randomized, blinded, placebo-controlled, 6-treatment, 4-period crossover, incomplete block design, in situ caries study in healthy adults who wear a removable bilateral mandibular partial denture. The denture will be modified to accommodate 4 gauze-covered specimens of human dental enamel (4x3mm) that have been previously demineralized in vitro to form either S or low-R lesions (2 specimens of each lesion type will be used with each participant). After 14 days of twice daily product use off-site, the 2 S lesion specimens will be removed at the study site, with the remaining 2 low-R lesion specimens removed at the study site after a further 14 days of product use. To determine the remineralization ability of the treatments, all specimens will be analyzed by transverse microradiography (TMR) and enamel fluoride uptake (EFU), with the S lesions additionally analyzed by surface micro hardness (SMH) and the low-R lesions additionally analyzed by quantitative light fluorescence (QLF).

Detailed description:

Arms:
arm 1: Participants will brush their natural teeth with a pre-wetted toothbrush and their assigned dentifrice for one timed minute, ensuring the enamel specimens retained within their mouths are not directly brushed. Participants should then rinse their mouths with 15ml of tap water for approximately 10s. arm 2: Participants will brush their natural teeth with a pre-wetted toothbrush and their assigned dentifrice for one timed minute, ensuring the enamel specimens retained within their mouths are not directly brushed. Participants should then rinse their mouths with 15ml of tap water for approximately 10s. arm 3: Participants will brush their natural teeth with a pre-wetted toothbrush and their assigned dentifrice for one timed minute, ensuring the enamel specimens retained within their mouths are not directly brushed. Participants should then rinse their mouths with 15ml of tap water for approximately 10s. arm 4: Participants will brush their natural teeth with a pre-wetted toothbrush and their assigned dentifrice for one timed minute, ensuring the enamel specimens retained within their mouths are not directly brushed. Participants should then rinse their mouths with 15ml of tap water for approximately 10s. arm 5: Participants will brush their natural teeth with a pre-wetted toothbrush and their assigned dentifrice for one timed minute, ensuring the enamel specimens retained within their mouths are not directly brushed. Participants should then rinse their mouths with 15ml of tap water for approximately 10s. arm 6: Participants will brush their natural teeth with a pre-wetted toothbrush and their assigned dentifrice for one timed minute, ensuring the enamel specimens retained within their mouths are not directly brushed. Participants should then rinse their mouths with 15ml of tap water for approximately 10s.

Interventions: intervention 1: 0.425 % w/w phytate,1150ppm F intervention 2: 0.85 % w/w phytate,1150ppm F intervention 3: 0.85 % w/w phytate,0.3%ZnCl2 0.5% sodium citrate, 1150ppm F intervention 4: 0 ppm F intervention 5: 1150ppm F intervention 6: 0.3%ZnCl2, 0.5% sodium citrate, 1150ppm F
Intervention descriptions: intervention 1: Participants were assigned with 1.5±0.1g twice daily dentifrice for one timed minute. intervention 2: Participants were assigned with 1.5±0.1g twice daily dentifrice for one timed minute. intervention 3: Participants were assigned with 1.5±0.1g twice daily dentifrice for one timed minute. intervention 4: Participants were assigned with 1.5±0.1g twice daily dentifrice for one timed minute. intervention 5: Participants were assigned with 1.5±0.1g twice daily dentifrice for one timed minute. intervention 6: Participants were assigned with 1.5±0.1g twice daily dentifrice for one timed minute.

Protocol document: