Salivary Biomarkers in Different Implant-Supported Prostheses

This observational cross-sectional study compared salivary biomarkers among adults with different types of implant-supported prosthetic rehabilitation and periodontally healthy adults with natural teeth. A total of 107 participants were included in four groups: periodontally healthy individuals with natural teeth, patients with implant-supported partial fixed prostheses and remaining natural teeth, patients with full-arch fixed implant-supported prostheses, and patients with implant-retained overdentures. The study measured three biomarkers in unstimulated whole saliva: secretory immunoglobulin A (sIgA), matrix metalloproteinase-8 (MMP-8), and matrix metalloproteinase-9 (MMP-9). These biomarkers are related to oral immune responses and tissue remodeling. The main aim was to determine whether salivary biomarker levels differed according to dentition status and type of implant-supported prosthesis. The study also examined relationships between these biomarkers and clinical parameters, including probing depth. No experimental treatment or intervention was assigned by the study protocol.

Inclusion Criteria: * Age 18 years or older. * Ability and willingness to provide written informed consent. * For the healthy dentate group: fully dentate individuals without dental implants who were systemically and periodontally healthy, with probing depths of 3 mm or less at all sites and full-mouth bleeding on probing below 10%. * For the implant groups: presence of an implant-supported partial fixed prosthesis, full-arch fixed implant-supported prosthesis, or implant-retained overdenture with osseointegrated implants restored with a definitive prosthesis in function for at least 6 months. Exclusion Criteria: * Antibiotic use within the preceding 6 months. * Periodontal therapy within the preceding 6 months. * Systemic conditions known to affect periodontal or immune status, including diabetes mellitus, cardiovascular disease, rheumatoid arthritis, systemic lupus erythematosus, or inflammatory bowel disease. * Systemic infectious diseases, including tuberculosis, hepatitis, or human immunodeficiency virus infection. * Mucocutaneous diseases affecting the oral mucosa, including lichen planus, pemphigus vulgaris, or chronic ulcerative stomatitis. * Ongoing systemic corticosteroid, immunosuppressant, or biologic therapy. * Pregnancy or lactation.