Effect of Non-Surgical Periodontal Therapy on Salivary Biomarkers in Smokers and Non-Smokers With Periodontitis (NSPT-Biomarker)

April 20, 2026 updated by: Hussein Abdul-Rassul Hateim, Al-Mustansiriyah University

The Significance of Non-Surgical Periodontal Therapy on Salivary Dkk-1, Sclerostin, and PLAP-1 Levels in Smoker and Non-Smoker Patients With Periodontitis: A Clinical Comparative Study

This study evaluates the effect of non-surgical periodontal therapy on salivary biomarkers (Dkk-1, Sclerostin, and PLAP-1) and clinical periodontal parameters in patients with periodontitis. Periodontitis is a chronic inflammatory disease that destroys tooth-supporting tissues. Smoking is a significant risk factor that worsens periodontal destruction and reduces the effectiveness of standard therapies.

  • The trial is a non-randomized comparative clinical study.
  • It includes 44 adult patients diagnosed with Stage II and III periodontitis.
  • The participants are divided into two equal groups: 22 current smokers and 22 non-smokers.
  • Participants will undergo a baseline examination, followed by standardized non-surgical periodontal therapy consisting of scaling and root planing.
  • A follow-up visit will be conducted six weeks post-therapy to repeat clinical measurements and saliva collection.
  • The primary objective is to evaluate changes in salivary biomarker levels and clinical parameters (Plaque Index, Gingival Index, bleeding on probing, Probing Pocket Depth, Clinical Attachment Level) after treatment.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Smoking is known to adversely affect the periodontium by altering cytokine production, impairing neutrophil function, and causing vasoconstriction that masks clinical inflammation. Because conventional diagnostic methods primarily measure past tissue destruction, there is growing interest in utilizing salivary biomarkers for real-time monitoring of disease activity. Specifically, Dickkopf-1 (Dkk-1) and Sclerostin (SOST) are elevated in periodontitis and actively suppress bone formation by antagonizing the Wnt/β-catenin pathway. Conversely, Periodontal Ligament-Associated Protein-1 (PLAP-1) plays a protective role in maintaining the periodontal ligament, and its presence in saliva may indicate active degradation. The collective behavior of these biomarkers in response to therapy among smokers is not fully understood.

This non-randomized comparative clinical trial aims to investigate the impact of smoking on these salivary biomarkers before and after non-surgical periodontal therapy. A total of 44 systemically healthy adult participants with Stage II and III periodontitis will be enrolled. The participants will be divided into two groups of 22: current smokers and non-smokers (defined as having never smoked or quit >5 years ago).

Study Procedures:

  • Baseline Visit: Participants will provide written informed consent, followed by the collection of unstimulated whole saliva via passive drooling. A full-mouth clinical examination will then be conducted using a UNC-15 periodontal probe. Clinical measurements include Plaque Index (PLI), Gingival Index (GI), Gingival Bleeding Index (GBI), Probing Pocket Depth (PPD), and Clinical Attachment Level (CAL).
  • Treatment Phase: Patients will receive standardized non-surgical periodontal therapy. This involves scaling at the first visit, followed by root planing after one week.
  • Follow-up Visit: Six weeks after completing the therapy, participants will return for a second saliva collection and a repeat of all clinical periodontal examinations.

Laboratory and Statistical Analysis:

  • Saliva samples will be kept in an ice box, centrifuged at 3000 rpm for 10 minutes, and the supernatant stored at -40 °C.
  • Salivary levels of Dkk-1, SOST, and PLAP-1 will be quantified using specific human ELISA kits.
  • Statistical analysis will assess intra-group and inter-group changes using SPSS, with a statistical significance level set at p ≤ 0.05.

Study Type

Interventional

Enrollment (Estimated)

44

Phase

  • Not Applicable

Contacts and Locations

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

Study Contact

Study Contact Backup

Study Locations

  • Iraq
    • Baghdad Governorate
      • Baghdad, Baghdad Governorate, Iraq, 10001
        • Recruiting
        • Al-Sadr Specialized Dental Center
      • Baghdad, Baghdad Governorate, Iraq

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

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Systemically healthy.
  • Diagnosed with Stage II and III periodontitis.
  • Presence of ≥ 20 teeth (excluding third molars).
  • Current smoker OR non-smoker

Exclusion Criteria:

  • Presence of systemic diseases affecting the periodontium.
  • Use of medications affecting inflammation.
  • Received periodontal therapy in the past 6 months.
  • Received antibiotic therapy in the last 3 months.
  • Alcohol use.

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

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Smokers
22 adult patients with Stage II or III periodontitis who currently smoke. They will receive standardized non-surgical periodontal therapy.
Procedure: Non-surgical periodontal therapy (Scaling and root planing)
Standardized non-surgical periodontal therapy performed over two visits (scaling at the first visit and root planing after one week).
Active Comparator: Non-smokers
22 adult patients with Stage II or III periodontitis who have never smoked or quit more than 5 years ago. They will receive standardized non-surgical periodontal therapy.
Procedure: Non-surgical periodontal therapy (Scaling and root planing)
Standardized non-surgical periodontal therapy performed over two visits (scaling at the first visit and root planing after one week).

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Salivary Dickkopf-1 (Dkk-1) Levels
Time Frame: Baseline and 6 weeks post-therapy.
Salivary Dkk-1 levels will be quantified using a specific human Enzyme-Linked Immunosorbent Assay (ELISA) kit.
Baseline and 6 weeks post-therapy.
Change in Salivary Sclerostin (SOST) Levels
Time Frame: Baseline and 6 weeks post-therapy.
Salivary Sclerostin (SOST) levels will be quantified using a specific human Enzyme-Linked Immunosorbent Assay (ELISA) kit.
Baseline and 6 weeks post-therapy.
Change in Salivary PLAP-1 (Asporin) Levels
Time Frame: Baseline and 6 weeks post-therapy.
Salivary Periodontal Ligament-Associated Protein-1 (PLAP-1) levels will be quantified using a specific human Enzyme-Linked Immunosorbent Assay (ELISA) kit.
Baseline and 6 weeks post-therapy.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Probing Pocket Depth (PPD)
Time Frame: Baseline and 6 weeks post-therapy.
PPD will be measured from the gingival margin to the base of the periodontal pocket using a UNC-15 periodontal probe.
Baseline and 6 weeks post-therapy.
Change in Clinical Attachment Level (CAL)
Time Frame: Baseline and 6 weeks post-therapy.
CAL will be measured from the cementoenamel junction (CEJ) to the base of the periodontal pocket using a UNC-15 periodontal probe.
Baseline and 6 weeks post-therapy.
Change in Plaque Index (PLI)
Time Frame: Baseline and 6 weeks post-therapy.
The amount of dental plaque will be assessed and scored clinically according to the Silness & Löe (1964) Plaque Index.
Baseline and 6 weeks post-therapy.
Change in Gingival Index (GI)
Time Frame: Baseline and 6 weeks post-therapy.
Gingival inflammation will be assessed and scored clinically according to the Löe & Silness (1963) Gingival Index.
Baseline and 6 weeks post-therapy.
Change in Gingival Bleeding Index (GBI)
Time Frame: Baseline and 6 weeks post-therapy.
The presence or absence of gingival bleeding will be assessed clinically according to the Ainamo & Bay (1975) Gingival Bleeding Index.
Baseline and 6 weeks post-therapy.

Collaborators and Investigators

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

Sponsor

Al-Mustansiriyah University

Investigators

  • Principal Investigator: Hussein Abdul-Rassul Hatiem, B.D.S., M.Sc. Student, College of Dentistry / Mustansiriyah University
  • Study Director: Ghasaq Asim Abdulwahab, B.D.S., M.Sc., Ph.D., College of Dentistry / Mustansiriyah 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)

January 1, 2026

Primary Completion (Estimated)

August 1, 2026

Study Completion (Estimated)

October 1, 2026

Study Registration Dates

First Submitted

April 9, 2026

First Submitted That Met QC Criteria

April 20, 2026

First Posted (Actual)

April 23, 2026

Study Record Updates

Last Update Posted (Actual)

April 23, 2026

Last Update Submitted That Met QC Criteria

April 20, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • MU-DENT-2025-01

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

IPD Plan Description

De-identified individual participant data will be made available upon reasonable request to the Principal Investigator.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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