Effect of Non-Surgical Periodontal Therapy on Salivary Biomarkers in Smokers and Non-Smokers With Periodontitis

Official title

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

Overview

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.

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.

Interventions

• 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).

Primary outcome measures

• Change in Salivary Dickkopf-1 (Dkk-1) Levels [Time frame: Baseline and 6 weeks post-therapy.]
• Change in Salivary Sclerostin (SOST) Levels [Time frame: Baseline and 6 weeks post-therapy.]
• Change in Salivary PLAP-1 (Asporin) Levels [Time frame: Baseline and 6 weeks post-therapy.]

Secondary outcome measures (5)

• Change in Probing Pocket Depth (PPD) [Time frame: Baseline and 6 weeks post-therapy.]
• Change in Clinical Attachment Level (CAL) [Time frame: Baseline and 6 weeks post-therapy.]
• Change in Plaque Index (PLI) [Time frame: Baseline and 6 weeks post-therapy.]
• Change in Gingival Index (GI) [Time frame: Baseline and 6 weeks post-therapy.]
• Change in Gingival Bleeding Index (GBI) [Time frame: Baseline and 6 weeks post-therapy.]

Eligibility criteria

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.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Non-randomized

Model

Parallel assignment

Masking

Open label

Primary purpose

Treatment

Study locations

Iraq · 2 centers

• Al-Sadr Specialized Dental Center — Baghdad
• Sadr Specialized Dental Center — Baghdad

Publications

• Saraç Atagün Ö, Baltacıoğlu E, Alver A, Balaban Yücesan F, Yuva P, Aslan Kehribar M, et al. Effects of smoking on local and systemic oxidative stress markers in individuals with periodontitis. Northwestern Med J. 2024;4(4):195-20. https://doi.org/10.54307/2024.NWMJ.71
• Gur B, Afacan B, Cevik O, Kose T, Emingil G. Gingival crevicular fluid periodontal ligament-associated protein-1, sclerostin, and tumor necrosis factor-alpha levels in periodontitis. J Periodontol. 2023 Oct;94(10):1166-1175. doi: 10.1002/JPER.22-0750. Epub 2023 Apr 19. PMID 37006132
• Liao C, Liang S, Wang Y, Zhong T, Liu X. Sclerostin is a promising therapeutic target for oral inflammation and regenerative dentistry. J Transl Med. 2022 May 13;20(1):221. doi: 10.1186/s12967-022-03417-4. PMID 35562828
• Azab E, Attia A, Yaghmoor W, Aldahlawi S, Youssef AR. The Impact of Nonsurgical Periodontal Therapy on Serum Levels of Dickkopf-Related Protein-1 in Smokers and Nonsmokers with Periodontitis: A Prospective Comparative Study. Clin Cosmet Investig Dent. 2022 Jun 28;14:191-198. doi: 10.2147/CCIDE.S362801. eCollection 2022. PMID 35789574

Identifiers

NCT: NCT07547202 · MU-DENT-2025-01

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗