Background/Objectives: Polymethyl methacrylate (PMMA)-based acrylic materials are widely used in dentistry, but they are not completely biologically inert and have been associated with hypersensitivity and allergic reactions in both patients and dental personnel. This narrative review aimed to synthesize the available evidence on (meth)acrylate-related hypersensitivity reactions in dentistry, with an emphasis on clinical manifestations, immunological mechanisms, and risk factors. Methods: A structured literature search was conducted in PubMed, Web of Science, and Scopus (15 August–1 September 2026), following the SANRA (Scale for the Assessment of Narrative Review Articles) guideline. After screening 408 records, 17 core articles were selected and grouped into four thematic categories: prevalence and clinical relevance, molecular and immunological mechanisms, clinical manifestations in patients, and occupational sensitization in dental personnel. Results: Confirmed (meth)acrylate sensitization ranges from 1.4% to 8% depending on population and testing methodology, remaining lower than metal allergy but clinically relevant. Haptenization through covalent binding of electrophilic monomers to host proteins underlies sensitization, while sublethal HEMA (2-hydroxyethyl methacrylate) exposure can induce measurable cellular stress independent of overt cytotoxicity. Patient presentations range from localized contact stomatitis to acute facial swelling, whereas dental personnel, particularly dental technicians, show disproportionately high occupational incidence rates. Testing restricted to HEMA alone may miss a substantial proportion of sensitized individuals. Conclusions: (Meth)acrylate hypersensitivity, although relatively uncommon, warrants increased diagnostic vigilance, broader patch-test panels, and improved occupational preventive measures. The current literature remains methodologically heterogeneous, underscoring the need for standardized testing series and larger prospective studies.