Caffeine Intake and Periodontal Treatment Outcomes

Effects of Dietary Caffeine Intake on Periodontal Treatment Outcomes: A Randomized Controlled Trial

This study will explore whether caffeine intake can affect recovery after periodontal (gum) treatment.

Periodontitis is a common gum disease caused by bacteria. Even after treatment, some people may still have ongoing inflammation or changes in oral bacteria. Researchers want to know if daily caffeine intake, such as from coffee, may help improve this condition.

In this study, about 90 adults with periodontitis will receive standard periodontal treatment. Participants will be randomly assigned to one of three groups: no caffeine intake, low caffeine intake, or moderate caffeine intake. They will follow these instructions for about 6 months.

Researchers will collect saliva samples and check gum health at several time points after treatment. Saliva will be used to measure inflammation markers and to study changes in oral bacteria. Researchers will also record clinical gum conditions, such as gum pocket depth and bleeding.

The goal of this study is to understand whether caffeine intake can help reduce inflammation, improve oral bacteria balance, and support recovery after periodontal treatment. The results may help provide simple dietary advice to improve long-term gum health.

Study Overview

• Status: Not yet recruiting
• Conditions: Periodontitis
• Intervention / Treatment: Dietary supplement: No Caffeine Intake; Dietary supplement: Low Caffeine Intake; Dietary supplement: Moderate Caffeine Intake

Detailed Description

This study is a randomized controlled trial designed to evaluate the effects of dietary caffeine intake on periodontal treatment outcomes and potential biological mechanisms.

Periodontitis is a chronic inflammatory disease associated with microbial imbalance and increased inflammatory activity. Although standard periodontal treatment can control disease progression, some individuals may continue to experience persistent inflammation during the maintenance phase.

Approximately 90 adults with periodontitis will be recruited and will receive standard non-surgical periodontal treatment. Participants will be randomly assigned to one of three groups according to caffeine intake: no intake, low intake, and moderate intake.

Participants will be followed for 6 months. Saliva samples will be collected at baseline and multiple follow-up time points. These samples will be used to assess inflammatory biomarkers and oral microbiome characteristics. Clinical periodontal parameters will also be recorded during follow-up.

This study aims to evaluate whether dietary caffeine intake influences inflammatory responses, oral microbiome characteristics, and clinical periodontal outcomes after periodontal treatment. The findings may provide evidence for incorporating dietary factors into periodontal disease management.

• Study Type: Interventional
• Enrollment (Estimated): 90
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Haoran Feng, BS; Phone Number: +86 13815309288; Email: fenghaoran0611@gmail.com
• Study Contact Backup: Name: Lei Wang, BS; Phone Number: +86 19961910284; Email: 657952067@qq.com

Study Locations

• China
  • Jiangsu
    • Xuzhou, Jiangsu, China, 221000
      • Affiliated Stomatological Hospital of Xuzhou Medical University
      • Contact: Haoran Feng, BS; Phone Number: +86 13815309288; Email: fenghaoran0611@gmail.com
      • Contact: Lei Wang, BS; Phone Number: +86 19961910284; Email: 657952067@qq.com
      • Principal Investigator: Haoran Feng, BS

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Adults aged 18 to 55 years.
• Diagnosed with periodontitis according to the 2018 Classification of Periodontal and Peri-Implant Diseases and Conditions.
• First visit for periodontal treatment and eligible for standard non-surgical periodontal therapy.
• Willing and able to comply with the dietary intervention and scheduled follow-up visits.
• Able to understand the study procedures and provide written informed consent.
• Able to communicate effectively and complete study questionnaires and follow-up assessments.

Exclusion Criteria:

• Pregnant or breastfeeding women, or women planning pregnancy during the study period.
• History of periodontal treatment within the previous 6 months.
• Current smokers or tobacco users.
• Use of antibiotics, anti-inflammatory drugs, immunosuppressive agents, or medications known to affect periodontal status within the previous 3 months.
• Presence of systemic diseases that may influence periodontal conditions, including diabetes mellitus, hypertension, or hyperlipidemia.
• Severe systemic diseases, psychiatric disorders, or other conditions that may interfere with study participation or protocol compliance.
• Allergy or intolerance to caffeine or inability to comply with the dietary caffeine intervention.
• Individuals with limited hand function or other conditions preventing adequate oral hygiene practices.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: No Caffeine Intake Group; Participants will receive standard non-surgical periodontal treatment and will be instructed to avoid dietary caffeine intake throughout the 6-month study period.	Dietary supplement: No Caffeine Intake; Participants will receive standard non-surgical periodontal treatment and will be instructed to avoid all dietary sources of caffeine throughout the 6-month study period.
Experimental: Low Caffeine Intake Group; Participants will receive standard non-surgical periodontal treatment and will consume approximately 50 mg of dietary caffeine per day throughout the 6-month study period.	Dietary supplement: Low Caffeine Intake; Participants will receive standard non-surgical periodontal treatment and will consume approximately 50 mg of dietary caffeine per day throughout the 6-month study period.
Experimental: Moderate Caffeine Intake Group; Participants will receive standard non-surgical periodontal treatment and will consume approximately 100 mg of dietary caffeine per day throughout the 6-month study period.	Dietary supplement: Moderate Caffeine Intake; Participants will receive standard non-surgical periodontal treatment and will consume approximately 100 mg of dietary caffeine per day throughout the 6-month study period.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean Change From Baseline in Salivary Matrix Metalloproteinase-8 Concentration at 2 Weeks, 1 Month, 3 Months, and 6 Months	Unstimulated whole saliva will be collected at baseline and at 2 weeks, 1 month, 3 months, and 6 months after initiation of the intervention. Salivary matrix metalloproteinase-8 concentration will be quantified using a commercial enzyme-linked immunosorbent assay kit. For each participant, change from baseline will be calculated separately at each post-baseline time point. The outcome will be summarized as the mean change from baseline for each intervention arm at each time point.	Baseline, 2 weeks, 1 month, 3 months, and 6 months after initiation of the intervention
Mean Change From Baseline in Salivary Interleukin-1 Beta Concentration at 2 Weeks, 1 Month, 3 Months, and 6 Months	Unstimulated whole saliva will be collected at baseline and at 2 weeks, 1 month, 3 months, and 6 months after initiation of the intervention. Salivary interleukin-1 beta concentration will be quantified using a commercial enzyme-linked immunosorbent assay kit. For each participant, change from baseline will be calculated separately at each post-baseline time point. The outcome will be summarized as the mean change from baseline for each intervention arm at each time point.	Baseline, 2 weeks, 1 month, 3 months, and 6 months after initiation of the intervention

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean Change From Baseline in Salivary Interleukin-6 Concentration at 2 Weeks, 1 Month, 3 Months, and 6 Months	Unstimulated whole saliva will be collected at baseline and at 2 weeks, 1 month, 3 months, and 6 months after initiation of the intervention. Salivary interleukin-6 concentration will be quantified using a commercial enzyme-linked immunosorbent assay kit. For each participant, change from baseline will be calculated separately at each post-baseline time point. The outcome will be summarized as the mean change from baseline for each intervention arm at each time point.	Baseline, 2 weeks, 1 month, 3 months, and 6 months after initiation of the intervention
Mean Change From Baseline in the Shannon Diversity Index of the Salivary Microbiome at 2 Weeks, 1 Month, 3 Months, and 6 Months	Salivary microbiome composition will be assessed using 16S ribosomal RNA gene sequencing. Alpha diversity will be quantified using the Shannon diversity index at baseline and at 2 weeks, 1 month, 3 months, and 6 months after initiation of the intervention. For each participant, change from baseline will be calculated separately at each post-baseline time point. The outcome will be summarized as the mean change from baseline for each intervention arm at each time point.	Baseline, 2 weeks, 1 month, 3 months, and 6 months after initiation of the intervention.
Mean Change From Baseline in the Relative Abundance of Porphyromonas gingivalis in Saliva at 2 Weeks, 1 Month, 3 Months, and 6 Months.	The relative abundance of Porphyromonas gingivalis in saliva will be estimated using 16S ribosomal RNA gene sequencing and reported as a percentage. For each participant, change from baseline will be calculated separately at 2 weeks, 1 month, 3 months, and 6 months after initiation of the intervention. The outcome will be summarized as the mean change in percentage points for each intervention arm at each time point.	Baseline, 2 weeks, 1 month, 3 months, and 6 months after initiation of the intervention.
Mean Change From Baseline in Full-Mouth Mean Probing Depth at 2 Weeks, 1 Month, 3 Months, and 6 Months	Probing depth will be measured in millimeters by one trained and calibrated periodontal examiner using a Florida electronic periodontal probe at six sites per tooth. For each participant, full-mouth mean probing depth will be calculated across all examined periodontal sites at each assessment. Change from baseline will be calculated separately at 2 weeks, 1 month, 3 months, and 6 months. The outcome will be summarized as the mean change from baseline for each intervention arm at each time point.	Baseline, 2 weeks, 1 month, 3 months, and 6 months after initiation of the intervention.
Mean Change From Baseline in Full-Mouth Mean Clinical Attachment Level at 2 Weeks, 1 Month, 3 Months, and 6 Months	Clinical attachment level will be measured in millimeters by one trained and calibrated periodontal examiner using a Florida electronic periodontal probe at six sites per tooth. For each participant, full-mouth mean clinical attachment level will be calculated across all examined periodontal sites at each assessment. Change from baseline will be calculated separately at 2 weeks, 1 month, 3 months, and 6 months. The outcome will be summarized as the mean change from baseline for each intervention arm at each time point.	Baseline, 2 weeks, 1 month, 3 months, and 6 months after initiation of the intervention
Mean Change From Baseline in the Percentage of Periodontal Sites With Bleeding on Probing at 2 Weeks, 1 Month, 3 Months, and 6 Months	Bleeding on probing will be assessed by one trained and calibrated periodontal examiner at six sites per tooth. For each participant, the percentage of periodontal sites with bleeding on probing will be calculated as the number of sites showing bleeding divided by the total number of sites examined, multiplied by 100. Change from baseline will be calculated separately at 2 weeks, 1 month, 3 months, and 6 months. The outcome will be summarized as the mean change in percentage points for each intervention arm at each time point.	Baseline, 2 weeks, 1 month, 3 months, and 6 months after initiation of the intervention

Collaborators and Investigators

• Sponsor: Haoran Feng
• Collaborators: Affiliated Stomatological Hospital of Xuzhou Medical University
• Investigators: Principal Investigator: Haoran Feng, Affiliated Stomatological Hospital of Xuzhou Medical University

Study record dates

Study Major Dates

• Study Start (Estimated): August 1, 2026
• Primary Completion (Estimated): December 31, 2027
• Study Completion (Estimated): December 31, 2027

Study Registration Dates

• First Submitted: July 26, 2026
• First Submitted That Met QC Criteria: July 30, 2026
• First Posted (Actual): August 5, 2026

Study Record Updates

• Last Update Posted (Actual): August 18, 2026
• Last Update Submitted That Met QC Criteria: August 14, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Keywords: Randomized controlled trial; Periodontitis; Oral microbiome; Non-surgical periodontal therapy; Dietary caffeine; Caffeine intake; Salivary inflammatory biomarkers
• Additional Relevant MeSH Terms: Periodontal Diseases; Mouth Diseases; Stomatognathic Diseases; Periodontitis
• Other Study ID Numbers: 2026-KY-008-02

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: De-identified individual participant data used for the published results will be shared, including demographic information, periodontal clinical parameters, salivary inflammatory biomarker measurements (MMP-8, IL-1β, and IL-6), and oral microbiome sequencing data. The study protocol and statistical analysis plan will also be available upon reasonable request.
• IPD Sharing Time Frame: Beginning 6 months after publication and ending 5 years after publication.
• IPD Sharing Access Criteria: De-identified individual participant data and supporting documents will be available to qualified researchers who submit a methodologically sound research proposal. Requests should be directed to the corresponding investigator. Access will be granted after review and approval of the proposal and execution of a data sharing agreement, in accordance with institutional policies and applicable ethical requirements.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No