This study will be conducted to evaluate the effect of arginine versus fluoride containing toothpaste on neutralization of microbial acid produced by Cariogenic bacteria in adult population using chair side assessment method.

.28 volunteer participants will be assigned in this study. Participants will be randomly divided into two groups(n=14) according to type of toothpaste D where groups D1 patient will use arginine containing toothpaste while groups D2 the patient will used the fluoride toothpaste with a number of 14 patients in each group. The pH will be evaluated according to time in relation to the brushing with toothpaste (T) where (T0) represent salivary pH before brushing with toothpaste , (T1) represent salivary pH 10 minutes after brushing with toothpaste at fixed time of the day.

Inclusion Criteria:

• Participants should be over 18 years of age.
• Systematically healthy.
• Not taking any medication interfering with saliva secretion.
• Participants who signed informed consent.

Exclusion Criteria:

• Participants with a compromised medical history.
• Participants under systemic disease treatment, with antibiotic, steroid or any medication known to cause dry mouth.
• Severe or active periodontal disease.
• History of allergies or other adverse reactions to arginine, or oral care product or their ingredient.