Ecological Effect of Arginine Dentifrice on Oral Microbiota

Not Applicable

Completed

Brief Summary: caries-free (CF) individuals caries-active (CA) individuals (DMFT ≥ 6) will be recruited. Subjects will be instructed to brush their teeth twice daily for 3 min using Colgate® Sensitive Pro-Relief® toothpaste (containing 8% arginine and 1450 ppm NaF) for 2 weeks. Supra- and subgingival plaque, saliva, and in situ plaque samples will be collected before and after the treatment for laboratory analyses.

Detailed Description: 21 caries-free (CF) individuals with no clinical evidence of caries experience \[decayed, missing and filled teeth (DMFT) = 0\] and 21 caries-active (CA) individuals (DMFT ≥ 6) will be recruited in the clinical trial. The exclusion criteria are: smoker or former smoker, presence of any systemic disease that could alter the production or composition of saliva, treatment with antibiotics, steroids or any medication known to cause dry mouth in the last 3 months, and presence of dental prostheses or orthodontic devices. Subjects will be instructed to brush their teeth twice daily for 3 min using Colgate® Sensitive Pro-Relief® toothpaste (containing 8% arginine and 1450 ppm NaF) for 2 weeks. Volunteers are asked to refrain from brushing and flossing their teeth, eating, and drinking anything other than water for 12 h prior to sample collection visits at the end of both phases. Supra- and subgingival plaque (15 subjects in each group), saliva (21 subjects in each group), and in situ plaque samples (3 subjects in each group) will be collected before and after the treatment. Scraped plaque and saliva samples will be immediately transferred to and dispersed in sterile micro-centrifuge tubes containing 1×phosphate-buffered saline (PBS), and stored at -80 °C until needed for analysis. The in situ plaque samples will be transferred into 4% paraformaldehyde, kept under 4 °C for 16 h, and then stored in 50% (v/v) ethanol at -20 °C.

Recruitment & Eligibility

Inclusion Criteria

caries-free individuals with no clinical evidence of caries experience [decayed, missing and filled teeth (DMFT) = 0] and caries-active individuals (DMFT ≥ 6) were recruited

Exclusion Criteria

smoker or former smoker, presence of any systemic disease that could alter the production or composition of saliva, treatment with antibiotics, steroids or any medication known to cause dry mouth in the last 3 months, and presence of dental prostheses or orthodontic devices.

Arm && Interventions

Group	Intervention	Description
Caries-active subjects	Colgate® Sensitive Pro-Relief® toothpaste	Subjects will use Colgate® Sensitive Pro-Relief® toothpaste for 2 weeks,.
Caries-free subjects	Colgate® Sensitive Pro-Relief® toothpaste	Subjects will use Colgate® Sensitive Pro-Relief® toothpaste for 2 weeks,.

Primary Outcome Measures

Name	Time	Method
The Change of Abundance of Specific Oral Microbes After Intervention as Assessed by 16S rRNA Sequencing	baseline , 2 week	Saliva and dental plaque samples will be collected, and the abundance of specific oral microbes such as Streptococcus mutans, Streptococcus sanguinis will be quantified by microbial 16S rRNA sequencing.

Secondary Outcome Measures

Name	Time	Method
The Change of Relative Activities of Microbial Enzymes After Intervention as Determined by Laboratory Enzymatic Assays	baseline ,2 week	Saliva and dental plaque samples will be collected and microbial enzyme activity will be quantified in the lab. Measures include relative enzyme activity of arginine deiminase, urease and lactase dehydrogenase as determined by standard laboratory enzymatic assay protocols.