Caries Prevention and Side Effects of Gum Arabic and Licorice Extracts Versus Chlorhexidine in High Caries Risk Patients

Inclusion Criteria: * High caries risk patients according to CAMBRA caries risk assessment tool * Baseline of at least 2-3 active non-cavitated or cavitated carious lesionssz * Baseline salivary Mutans streptococci count ≥ 106 CFU/ml * Baseline salivary Lactobacilli count ≥ 104 CFU/ml * Baseline DMF index of at least 3-5 * Cooperative patients approving to participate in the study Exclusion Criteria: * Any systemic conditions, severe medical complications * Significant past or current medical condition that may affect oral health or oral flora * Current medications (may affect the oral flora or salivary flow) * Allergy to any of the ingredients of the study products * Use of any antibiotics within the past 3 months * Use of any mouth rinses within the past 3 months * Current periodontitis (sites of probing pocket depth ≥ 5 mm) * Evidence of parafunctional habits * Dysfunction of temporomandibular joint * Presence of developmental dental anomalies * Presence of orthodontic appliance or removable prosthesis * Pregnancy * Xerostomia * Heavy smoking * Drug or alcohol addiction, or conditions that may decrease adhering to study protocol * Lack of compliance