Streptococcus mutans and Lactobacillus acidophilus are the most common cariogenic microorganisms. Chlorhexidine has been the most widely used antibacterial mouthwash in dentistry. On the other hand, few studies have reported the antibacterial potential of Propolis and Ozonated olive oil as antibacterial agents that can be used as alternatives to Chlorhexidine. This study aims to evaluate and compare the antibacterial effect of Ozonated olive oil, Propolis, and Chlorhexidine on S. mutans and L. acidophilus count in pediatric patients.

Inclusion Criteria:

• High caries risk patients, according to AAPD guidelines, with visible caries or radiographic penetration into dentin, white spots on smooth surfaces, or recent restorations or missing teeth due to caries.
• Cooperative children according to Frankl's rating (score 3 & 4)

Exclusion Criteria:

• Children with any medical illness or oral infection or those who received any type of antibiotic treatment or mouthwash for two weeks before or during the study were excluded