Evaluation of the Effects of Levodopa-Benserazide Drug Combination on Periodontal Status in Patients With Parkinson's Disease

September 1, 2026 updated by: Özlem SARAÇ ATAGÜN, Saglik Bilimleri Universitesi

The Effect of Levodopa-Benserazide Combination on Periodontal Status in Patients With Parkinson's Disease: A Cross-Sectional Study

The aim of this study is to evaluate the effects of Levodopa-Benserazide drug combination on periodontal status and salivary cytokine levels in patients with Parkinson's disease. The study includes four groups: Parkinson's patients with periodontitis, periodontally healthy Parkinson's patients, participants without Parkinson's with periodontitis, and periodontally healthy participants without Parkinson's. Clinical periodontal parameters (Plaque Index, Gingival Index, Bleeding on Probing, Pocket Depth, and Clinical Attachment Loss) will be recorded. Unstimulated saliva samples will be collected to analyze the levels of TNF-alpha, RANTES, IL-10, IL-13, Total Oxidant Status (TOS), Total Antioxidant Status (TAS), and Malondialdehyde (MDA).

Study Overview

Status

Active, not recruiting

Conditions

Detailed Description

Background and Rationale: Parkinson's Disease (PD) is a progressive neurodegenerative disorder characterized by the degeneration of dopaminergic neurons in the substantia nigra. Chronic inflammation and oxidative stress are considered significant factors in the progression of PD. Levodopa (L-DOPA), combined with Benserazide, remains the most effective pharmacological treatment for managing PD symptoms. Periodontitis is a chronic inflammatory disease that leads to the destruction of tooth-supporting tissues and is associated with elevated levels of local and systemic inflammatory cytokines such as TNF-alpha, IL-10, IL-13, and RANTES. Recent studies suggest a bidirectional relationship between systemic inflammation and neurodegenerative diseases. This study aims to evaluate the effects of the Levodopa-Benserazide drug combination on periodontal status and salivary inflammatory cytokine levels in patients with Parkinson's Disease.

Study Design and Setting: This cross-sectional, case-control study will be conducted in collaboration with the Department of Periodontology at the University of Health Sciences, Gulhane Faculty of Dentistry, and the Department of Neurology at Hacettepe University Faculty of Medicine.

Participants and Groups: The study will include a total of 136 participants divided into four groups (n=34 per group):

Parkinson's patients with periodontitis

Periodontally healthy Parkinson's patients

Systemically healthy participants with periodontitis (Control)

Systemically and periodontally healthy participants (Control)

Diagnosis of Parkinson's Disease will be confirmed based on the United Kingdom Parkinson's Disease Society Brain Bank Criteria.

Exclusion Criteria: Participants will be excluded if they have active smoking habits, diabetes mellitus, history of antibiotic or anti-inflammatory drug use in the last 3 months, periodontal treatment in the last month, use of probiotics or oral antiseptics in the last month, history of radiotherapy/chemotherapy in the last 6 months, presence of fewer than 16 natural teeth, use of removable partial or complete dentures, or inability to give informed consent due to dementia or other cognitive impairments.

Clinical Evaluations: All participants will undergo a comprehensive periodontal examination. Clinical parameters including Plaque Index (PI) (Silness-Löe), Gingival Index (GI) (Löe-Silness), Bleeding on Probing (BOP), Pocket Depth (PD), and Clinical Attachment Loss (CAL) will be recorded using a Williams periodontal probe. Measurements for PD, CAL, and BOP will be taken at six sites per tooth, while PI and GI will be recorded at four sites per tooth.

Biochemical Analysis: Unstimulated whole saliva samples will be collected from all participants between 09:00 and 10:00 AM to minimize circadian rhythm variations. Participants will be asked to refrain from eating, drinking, or oral hygiene procedures for at least one hour prior to collection. Samples will be stored at -80°C until analysis.

Inflammatory cytokines (TNF-alpha, RANTES, IL-10, IL-13) will be analyzed using Enzyme-Linked Immunosorbent Assay (ELISA).

Oxidative stress markers, including Total Oxidant Status (TOS), Total Antioxidant Status (TAS), and Malondialdehyde (MDA), will be measured using spectrophotometric methods.

Statistical Analysis: Data distribution will be assessed using the Kolmogorov-Smirnov test. Differences between groups will be analyzed using ANOVA (for normally distributed data) or appropriate non-parametric tests. Categorical variables will be compared using the Chi-square test. A p-value of <0.05 will be considered statistically significant.

Study Type

Observational

Enrollment (Estimated)

136

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

Turkey (Türkiye)
- - Ankara, Turkey (Türkiye), 06010
    - Sağlık Bilimleri Üniversitesi Gülhane Diş Hekimliği Fakültesi

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

Child
Adult
Older Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

Participants will be recruited from the Department of Neurology at Hacettepe University Faculty of Medicine (Parkinson's patients) and the Department of Periodontology at the University of Health Sciences, Gulhane Faculty of Dentistry (Periodontitis patients and healthy controls).

Description

Inclusion Criteria:

Diagnosis of Parkinson's Disease according to United Kingdom Parkinson's Disease Society Brain Bank Criteria (for study group).
Systemically healthy individuals (for control group).
Willingness to participate and sign informed consent.

Exclusion Criteria:

Active smoking.
Comprehensive periodontal treatment within the last month.
Oral, respiratory, or digestive system diseases within the last 3 months.
Fewer than 16 natural teeth.
Use of full or removable partial dentures.
Dementia or inability to provide consent.
Serious active illnesses or substance abuse.
Antibiotic treatment within the last 3 months.
Probiotic use within the last month.
Radiotherapy/chemotherapy within the last 6 months.
Use of oral antiseptics within the last month.
Diabetes mellitus.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Number of groups / cohorts

Cohorts and Interventions

Group / Cohort
Parkinson's - Periodontitis Patients diagnosed with Parkinson's Disease who also have Periodontitis.
Parkinson's - Healthy Patients diagnosed with Parkinson's Disease who are periodontally healthy.
Control - Periodontitis Systemically healthy participants (non-Parkinson) who have Periodontitis.
Control - Healthy Systemically and periodontally healthy participants.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Salivary Inflammatory Cytokine Time Frame: Day 1	TNF-alpha,	Day 1
Salivary Inflammatory Cytokine Time Frame: Day 1	RANTES	Day 1
Salivary Inflammatory Cytokine Time Frame: Day 1	IL-10	Day 1
Salivary Inflammatory Cytokine Time Frame: Day 1	IL-13	Day 1
Salivary Oxidative Stress Levels Time Frame: Day 1	Total Oxidant Status (TOS)	Day 1
Salivary Oxidative Stress Levels Time Frame: Day 1	Total Antioxidant Status (TAS)	Day 1
Salivary Oxidative Stress Levels Time Frame: Day 1	Malondialdehyde (MDA)	Day 1

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Clinical Periodontal Parameters Time Frame: Day 1	Assessment of Plaque Index (PI)	Day 1
Clinical Periodontal Parameters Time Frame: Day 1	Bleeding on Probing (BOP)	Day 1
Clinical Periodontal Parameters Time Frame: Day 1	Gingival Index (GI)	Day 1
Clinical Periodontal Parameters Time Frame: Day 1	Pocket Depth (PD)	Day 1
Clinical Periodontal Parameters Time Frame: Day 1	Clinical Attachment Loss (CAL)	Day 1

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Saglik Bilimleri Universitesi

Collaborators

Hacettepe University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

February 10, 2026

Primary Completion (Estimated)

October 10, 2026

Study Completion (Estimated)

November 10, 2026

Study Registration Dates

First Submitted

February 2, 2026

First Submitted That Met QC Criteria

February 11, 2026

First Posted (Actual)

February 12, 2026

Study Record Updates

Last Update Posted (Actual)

September 4, 2026

Last Update Submitted That Met QC Criteria

September 1, 2026

Last Verified