Inclusion Criteria:  Sex: female or male. Age: 25 - 55 years. Medically controlled according to medical coding of review of systems (ROS)  Exclusion Criteria:  Tobacco smoking for at least 6 months before the study enrollment  Participants with ill-fitting restorations in both upper first molars that affect the stability of the stent. Participants not following oral hygiene instructions. Participants on dental treatment during the study period. Participants with a history of drug administration Vulnerable group. Participants with long-term mouthwash administration.