This randomized controlled trial evaluates the effect of diode laser pre-treatment on the retention and caries prevention of giomer-based fissure sealants in young adults aged 17-22 years. The study compares sealant application with and without diode laser conditioning on molars with ICDAS 0-2 fissures over a 12-month follow-up period. Primary outcome is sealant retention using Simonsen's criteria, while secondary outcome is caries prevention using modified USPHS criteria. The study hypothesizes that diode laser pre-treatment may improve sealant retention and enhance caries prevention by modifying enamel surface characteristics and improving sealant penetration.