This research aims to explore the influence of vitamin D on the body's defense system by examining its impact on specific proteins involved in immune response and inflammation in the soft tissues surrounding dental implants. Also aims to determine how vitamin D levels affect these proteins and their role in protecting peri-implant tissues from microbial infections and inflammation.

This cross-sectional clinical study examined 33 patients with 105 dental implants, classified as having either healthy peri-implant tissues or peri-implant diseases. Participants had not received peri-implant treatment in the past six months or taken medications affecting peri-implant tissues in the last three months. Eligible implants had been functional for at least 12 months with prosthetic superstructures that allowed sample collection. Patients with uncontrolled systemic conditions, metabolic bone diseases, autoimmune disorders, or those who were pregnant or breastfeeding were excluded. Clinical assessments were conducted at six peri-implant sites, measuring probing depth (PD), clinical attachment level (CAL), modified plaque index (mPI), modified sulcus bleeding index (mSBI), and keratinized mucosa width (KMW). Bone loss was evaluated using radiographs. Patients were categorized into three groups based on the 2017 Classification of Periodontal and Peri-implant Diseases: peri-implant health, peri-implant mucositis, and peri-implantitis (35 implants per group). Peri-implant sulcus fluid (PISF) samples were collected for 25(OH)D and LL-37 analysis using enzyme-linked immunosorbent assay (ELISA). Statistical analysis included normality tests (Kolmogorov-Smirnov), descriptive statistics, one-way ANOVA with Tukey HSD, Kruskal-Wallis with Dunn's test, chi-square tests, and Spearman's correlation for non-normally distributed data.