Beyond Glycemic Control: Periodontal, Salivary, and Oral Microbiome Effects of GLP-1 Receptor Agonists—A Scoping Review of Clinical and Preclinical Evidence

Background/Objectives: Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are widely used to treat type 2 diabetes and obesity, yet their periodontal, peri-implant, salivary, and oral microbial effects remain incompletely characterized. This scoping review mapped the clinical and preclinical evidence on GLP-1RA-related oral effects, investigated mechanisms, and knowledge gaps. Methods: PubMed, Scopus, and the Web of Science Core Collection were searched from inception to 9 September 2026. Original human, animal in vivo, in vitro/ex vivo, and mixed-design studies were eligible when a GLP-1RA was a principal intervention or exposure and a relevant oral or orofacial outcome was reported. Two reviewers independently screened records. Study characteristics, interventions, outcomes, and findings were charted and synthesized descriptively. The review followed Joanna Briggs Institute methodology and PRISMA-ScR guidance and was registered on the Open Science Framework after study selection but before completion of the methodological appraisal and manuscript. Results: Twenty-seven publications were included, 23 of which were wholly or partly preclinical. Four publications were exclusively human, and one mixed-design publication included an additional human observational component. Experimental findings suggested anti-inflammatory, antioxidant, and osteogenic effects, but molecular responses were not consistently accompanied by structural benefits. Evidence concerning salivary function, oral microbial changes, and orofacial adverse events was limited and heterogeneous. Human findings were derived from non-randomized observational and descriptive designs. Conclusions: Evidence of potential oral effects is predominantly experimental, and human data are insufficient to establish clinical benefit or causality. Prospective controlled studies with standardized clinical outcomes are needed to determine whether experimental findings translate into meaningful oral-health benefits.