Regulatory effects of some neuropeptides substance-P (SP), neurokinin-A (NKA), calcitonin gene-linked peptide (CGRP) and neuropeptide-Y (NPY) )on inflammatory responses in periodontal disease has been described; however, the impact of neuropeptide levels are not clearly defined in healthy and diseased peri-implant tissues.ın order to evaluate the situation, thirty-nine implants that have been loaded over the past 12 months and their symmetrically matching teeth were evaluated using a split-mouth study design. Clinical periodontal examinations included the Silness-Löe plaque index, Löe-Silness gingival index, bleeding on probing, probing pocket depth and clinical attachment level parameters were determined. Gingival crevicular fluid (GCF)/Periimplant sulcular fluid (PISF) samples were collected, and the levels of the neuropeptides were determined by enzyme-linked immunosorbent assay. Correlations between GCF/PISF neuropeptide levels and the clinical examination parameters were evaluated in the peri-implant/periodontal soft tissues.

Inclusion Criteria:

The main inclusion criteria for patient selection were as follows:

• Compliance with systematic maintenance care;
• Adult, non-smoker, systemically healthy
• Not using any medicament for the last 6 months ;
• Partially dentated patient treated with implant-supported metal ceramic full crowns and/or fixed partial dentures
• As the study was split-mouth designed, in each individual at least one implant and one matching tooth in the same mouth symmetrically representing the same tooth group (premolars/molars);
• A single type of metal ceramic implant restoration that is functional for at least 1 year; and a matching tooth with no dental or endodontic restorations.

Exclusion Criteria:

• Medical history of cancer, rheumatoid arthritis, diabetes mellitus, or cardiovascular disease and any other systemic disease affecting lipid metabolism (i.e. impaired glucose tolerance, metabolic syndrome);
• Compromised immune system;
• Pregnancy, menopause, or lactation;
• Ongoing drug therapy that might affect the clinical characteristics of periodontitis and lipid metabolism;
• Dental treatment during the 6 months prior to data collection.

Thirty-nine male, systemically healthy adult individuals (35-55 years old) and 39 dental implants were recruited for the present study. The same implant system was utilized for the treatments and the clinical treatment procedures were completed by the same two clinicians at the Ondokuz Mayis University Dental Faculty between 2011 and 2013.