This randomized controlled clinical trial investigates the comparative efficacy of different laser systems and fluoride-based treatments for managing dentinal hypersensitivity, a prevalent clinical condition characterized by sharp, transient pain from exposed dentin in response to thermal, evaporative, tactile, or chemical stimuli. The study will recruit 96 participants aged 18-45 years with dentinal hypersensitivity scores ≥4 on a Visual Analogue Scale (VAS), randomly allocating them into four equal groups (n=24 each): Group 1 receiving Erbium:YAG laser treatment (2940 nm, 80mJ, 2Hz) which works through thermal tubule occlusion; Group 2 receiving Diode laser photobiomodulation therapy (650 nm, 100mW, 2J total dose) targeting neural modulation; Group 3 receiving combination therapy of Diode laser with 5% sodium fluoride varnish to exploit synergistic mechanisms; and Group 4 receiving fluoride varnish alone as the control comparator. The primary outcome measures dentinal hypersensitivity reduction using VAS scores (0-10 scale) assessed through standardized evaporative stimulus tests at baseline, 1 week, 4 weeks, and 6 months post-treatment, while secondary outcomes include patient satisfaction and treatment tolerability. Conducted at the Conservative Dentistry Department, Faculty of Dentistry, Cairo University, with blinded outcome assessors and standardized protocols, this superiority trial addresses the clinical need for evidence-based, long-term effective treatments for dentinal hypersensitivity by comparing individual laser modalities against combination therapy and established fluoride treatments, potentially establishing optimal therapeutic protocols that provide both immediate relief and sustained tubule occlusion or neural modulation for improved patient quality of life.