The aim of this study was to determine the effect of orthodontic treatment with aligner on changes in osteoprotegerin (OPG) and receptor activator of NF-κB ligand (RANKL) levels in saliva samples and to investigate the possible relationship between periodontal clinical parameters. Materials and Methods: A total of 25 (n=25) saliva samples were taken from systemically healthy non-smoking individuals who were planned to receive orthodontic treatment with aligner before treatment. Whole mouth clinical periodontal measurements including probing depth (PD), clinical attachment level (CAL), bleeding on probing (BOP), gingival index (GI) and plaque index (PI) were also recorded and repeated at 1 and 3 months. Enzyme-linked immunosorbent assay (ELISA) was used to determine OPG and RANKL levels in biological samples.

Inclusion Criteria:

• Systemically healthy (The determination of healthy volunteers will be based on the statements of the patients in the anamnesis. No additional examinations will be made.)
• Must receive orthodontic treatment with aligners and must have accepted the treatment
• Non-smoker
• No medication for continuous use
• Those who have not used antibiotics, anti-inflammatory and systemic corticosteroid drugs in the last 6 months.
• Not in pregnancy or lactation period.

Exclusion Criteria:

• Any oral or systemic disease
• Regularly using a systemic medication
• During pregnancy or lactation
• Received periodontal treatment within the last 6 months.
• Those who received antibiotic, anti-inflammatory or systemic corticosteroid medication in the last 6 months
• Smokers are not included in the study