Dental Amalgam and Oral Biological Responses: A Narrative Review of Current Evidence

Dental amalgam remains widely used in restorative dentistry due to its durability and cost-effectiveness, yet concerns persist regarding potential biological effects related to mercury release. This narrative review critically synthesizes current evidence on oral mucosal alterations and salivary biomarker changes reported in association with amalgam restorations. Experimental research supports biological plausibility for oxidative and inflammatory responses to mercury exposure; however, most human evidence derives from observational studies demonstrating heterogeneous associations rather than consistent causal relationships. Reported variations in salivary biomarkers, including interleukin-8 and ceruloplasmin, are generally modest and influenced by confounding factors such as periodontal status, smoking, and systemic inflammation. Histopathological findings adjacent to amalgam restorations include epithelial and inflammatory changes, though many are nonspecific and comparable to other chronic irritative conditions. Overall, current clinical and epidemiological data do not indicate uniform or clinically significant adverse effects in the general population attributable solely to dental amalgam. Regulatory phase-down initiatives primarily reflect environmental and precautionary policies. Available evidence supports a balanced and evidence-based interpretation of amalgam-related biological findings in contemporary dental practice.