Chlorhexidine (CHX) is the main chemical agent for treating and managing plaque and reducing gingivitis. It is a wide-spectrum antibacterial agent. Mouthwash used for oral hygiene can cause degradation of the resin composite surface because of its components, such as detergent, alcohol, emulsifier, and organic acid. Enhancing the baseline data and enhancing instructions, would improve dental student's understanding and awareness while protecting the integrity of composite restorations and patient's oral health. To evaluate the effect of chlorhexidine mouthwash on color stability and surface roughness of conventional nano-hybrid composite. A cross-sectional study was conducted. The survey was distributed among undergraduate dental students and interns in Saudi Arabia. Analyzes and entry methods were performed by using SPSS version 21 for the data gathered through surveys. The Statistical Package for Social Sciences was used to import the overall response rate and the percentage of responses for each question. One thousand and forty-one participants enrolled in this study, and the majority of respondents fall within the 21-25 age group accounting for 93.0% of the total sample. 48.4% were males and 51.6% were females. Findings showed a breakdown of the frequency and percentage distribution of individuals categorized by their level of knowledge. The parameter "High knowledge" is represented by 179 individuals, accounting for 17.2% of the total sample. The knowledge and awareness level of the effect of mouth rinse, specifically chlorhexidine, on tooth-colored composite restorations among dental students in KSA is acceptable based on the study results.
