This chapter examines the pivotal role of bacterial biofilms in the pathogenesis of dental diseases and their impact on oral health. It reviews the molecular and cellular mechanisms underlying biofilm formation, including bacterial adhesion, extracellular polymeric substance production, quorum sensing (QS), and genetic regulation. These processes contribute to the development and persistence of oral infections. Diagnostic challenges are discussed by reviewing conventional clinical examinations and radiographic techniques alongside advanced molecular and imaging methods. However, the inherent resistance of biofilm-embedded bacteria to antimicrobials and the limitations of current diagnostic tools underscores the need for more refined approaches. Prevention and management strategies are explored, emphasizing rigorous oral hygiene practices, dietary modifications to reduce fermentable carbohydrate intake, and professional interventions including mechanical debridement and adjunctive antimicrobial therapies. Emerging therapies—such as nanoparticle-based antimicrobials, QS inhibitors, guided biofilm therapy, and photodynamic therapy—offer promising alternatives to traditional treatments. Prevention and management of biofilm-associated dental diseases requires integrated, multidisciplinary strategies, incorporating personalized medicine and advanced diagnostic technologies.