GingivitisPERIOCLOCKNCT07452783
Circadian Clock Gene Expression in Periodontal Disease
An observational study of Gingivitis and Periodontitis, run by Inonu University at 1 site in Turkey (Türkiye).
Trial summary
This observational study aims to investigate whether periodontal inflammation is associated with alterations in the expression of circadian clock-related genes and proteins in gingival tissues. Circadian rhythms regulate many biological processes, including immune responses and inflammation. Read more about this study
- Who is it for?
- Ages 25 years and olderHealthy volunteers can take part
- Conditions the study is for
- Gingivitis, Periodontitis
- What is being tested?
- Gingival Tissue Biopsy
- Type of treatment
- Surgery or procedure
- How many people
- 60 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 20 Jan 2024to 1 Dec 2025
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 25 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Systemically healthy adult individuals seeking care at the Department of Periodontology, Inonu University Faculty of Dentistry, were recruited. Participants were categorized into three groups based on periodontal status: periodontally healthy, gingivitis, and Stage III Grade B periodontitis according to the 2018 classification of periodontal diseases. All participants required clinically indicated periodontal procedures from which gingival tissue samples could be obtained.
Who may be able to join
- Adults aged 18 years or older
- Systemically healthy individuals
- Presence of at least 20 natural teeth
- Individuals classified as periodontally healthy, gingivitis, or Stage III Grade B periodontitis according to the 2018 classification of periodontal diseases
- Willingness to provide written informed consent
Who cannot join
- Presence of any systemic disease affecting periodontal status (e.g., diabetes mellitus, autoimmune diseases, cardiovascular diseases)
- Use of antibiotics or anti-inflammatory medications within the previous 3 months
- Periodontal therapy within the last 6 months
- Current smokers or individuals who quit smoking within the past 5 years
- Pregnancy or lactation
- Use of medications known to influence immune or inflammatory responses
- History of systemic conditions that may affect wound healing
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Inonu University Faculty of Dentistry
Malatya, 44210
About this study
Official title: Periodontal Inflammation Is Associated With Disruption of Gingival Circadian Clock Gene and Protein Expression in Individuals With Comparable Chronotype Profiles
This observational study aims to investigate whether periodontal inflammation is associated with alterations in the expression of circadian clock-related genes and proteins in gingival tissues. Circadian rhythms regulate many biological processes, including immune responses and inflammation. Although experimental studies suggest a link between circadian disruption and periodontal disease, human data under controlled chronotype conditions are limited.
A total of 60 systemically healthy, non-smoking individuals aged 22-45 years with comparable sleep patterns (intermediate chronotype and 6-9 hours of sleep) were included. Participants were classified as periodontally healthy, gingivitis, or stage III grade B periodontitis according to established diagnostic criteria. Gingival tissue samples were collected during clinically indicated procedures within a standardized morning time window (09:00-11:00).
Read more
Gene expression levels of circadian clock components (CLOCK, BMAL1, PER1-3, CRY1-2, Rev-Erb-β, ROR-α) and inflammatory mediators (IL-1β, IL-6, TNF-α, NF-κB, IFN-γ, RANKL, OPG) were analyzed using RT-qPCR, Western blot, and ELISA techniques. Associations between molecular findings and clinical periodontal parameters were evaluated.
The study seeks to clarify whether periodontal disease itself may disrupt local circadian regulatory mechanisms in gingival tissues.
Read the detailed description
Circadian rhythms are generated through transcriptional-translational feedback loops involving core clock genes such as CLOCK, BMAL1, PER1-3, CRY1-2, ROR-α, and REV-ERB-β. These molecular oscillators regulate immune function, inflammatory signaling, and bone metabolism. Experimental evidence suggests that circadian dysregulation may aggravate periodontal inflammation and alveolar bone loss; however, comprehensive human data under controlled chronotype conditions remain limited.
This single-center, observational case-control study includes 60 systemically healthy, non-smoking individuals (30 males, 30 females) aged 22-45 years. Chronotype was determined using the Munich Chronotype Questionnaire, and only individuals with intermediate chronotype and self-reported sleep duration between 6 and 9 hours were included to minimize circadian variability.
Participants were classified into three groups (n=20 per group): periodontally healthy, gingivitis, and stage III grade B periodontitis according to the 2017 World Workshop criteria. Comprehensive periodontal examination included plaque index, gingival index, bleeding on probing, probing depth, and clinical attachment loss measurements. Gingival tissue biopsies were obtained during clinically indicated procedures and collected between 09:00 and 11:00 a.m. to standardize circadian timing. Samples were stored at -80°C until molecular analysis.
Total RNA was extracted from gingival tissues, and gene expression was quantified using RT-qPCR with normalization to β-actin and analysis via the 2^-ΔΔCT method. Protein expression of circadian clock components was assessed by Western blot, and inflammatory cytokine levels (IL-1β, IL-6) were quantified by ELISA. Correlation analyses were performed to evaluate associations between circadian gene expression, inflammatory mediators, and clinical periodontal parameters.
The primary objective is to determine whether periodontal inflammation is associated with disruption of gingival circadian clock gene and protein expression in individuals with comparable chronotype profiles.
- Conditions
- Gingivitis, Periodontitis
- Being tested
- Gingival Tissue Biopsy
- Keywords
- Circadian Rhythm, BMAL1, CLOCK, Per1, Per2, Per3, CRY1, CRY2, ROR-α, Rev-Erb-β, IL-1β, IL-6, TNF-α, IFN-γ, RANKL, OPG, NF-κB, Periodontitis, Inflammation
- Medical subject headings
- Gingivitis, Periodontitis, Inflammation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Gingival Tissue BiopsyProcedure or surgery
Collection of gingival tissue samples from interproximal sites during clinically indicated periodontal procedures for molecular and protein expression analyses.
| Study group | Role | What they receive |
|---|---|---|
| Periodontally Healthy | Systemically healthy individuals with clinically healthy periodontal tissues, no attachment loss, and no radiographic bone loss. Receives: Procedure: Gingival Tissue Biopsy | |
| Gingivitis | Systemically healthy individuals presenting with gingival inflammation without clinical attachment loss or radiographic bone loss. Receives: Procedure: Gingival Tissue Biopsy | |
| Stage III Grade B Periodontitis | Systemically healthy individuals diagnosed with Stage III Grade B periodontitis according to the 2018 classification of periodontal diseases. Receives: Procedure: Gingival Tissue Biopsy |
What is being measured
The primary outcome is the main question the study is designed to answer.
Relative mRNA Expression Levels of Circadian Clock Genes in Gingival Tissue
Quantitative assessment of BMAL1, CLOCK, PER1, PER2, PER3, CRY1, CRY2, REV-ERBβ, and ROR-α mRNA expression levels in gingival tissue samples using real-time quantitative polymerase chain reaction (RT-qPCR). Expression levels will be calculated as relative fold changes normalized to housekeeping genes and compared among periodontally healthy, gingivitis, and Stage III Grade B periodontitis groups.
Measured: At the time of gingival tissue collection (single time point)
Secondary outcomes (3)
Pro-inflammatory Cytokine Expression Levels
Relative mRNA expression levels of IL-1β, IL-6, TNF-α, and IFN-γ in gingival tissue samples assessed by RT-qPCR and compared among study groups.
Measured: At the time of tissue collection
NF-κB Expression Level
Relative expression level of NF-κB in gingival tissue samples determined by molecular analysis and compared among study groups.
Measured: At the time of tissue collection
Bone Metabolism Markers
Relative mRNA expression levels of RANKL and OPG in gingival tissue samples and evaluation of the RANKL/OPG ratio among study groups.
Measured: At the time of tissue collection
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Mar 2026
- Study start20 Jan 2024
- Primary completion2 Mar 2025
- Study completion1 Dec 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (6)Papers the sponsor has linked to this study.
- Other trials for GingivitisStudies of the same condition, open and under way.
- More trials run by Inonu UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case-control
- Time perspective
- Cross-sectional
- Enrolment
- 60 participants (actual)
Sponsor and investigators
- Lead sponsor
- Inonu University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Cuneyt Asim Aral, Inonu University
- Investigators
- Cuneyt A Aral, Professor, DDS, PhD, Study chair, Inonu University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07452783
- Sponsor's protocol ID
- IUCREC.2024/05.13
- Other IDs
- TDH-2024-3463
- Acronym
- PERIOCLOCK
- Status last verified
- Mar 2026
- First submitted
- 1 Mar 2026
- Last updated
- 6 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: De-identified individual participant data may be made available upon reasonable request to the corresponding investigator, subject to institutional approval and ethical considerations.
Publications
Kapila YL. Oral health's inextricable connection to systemic health: Special populations bring to bear multimodal relationships and factors connecting periodontal disease to systemic diseases and conditions. Periodontol 2000. 2021 Oct;87(1):11-16. doi: 10.1111/prd.12398.
PubMed 34463994Chapple ILC, Mealey BL, Van Dyke TE, Bartold PM, Dommisch H, Eickholz P, Geisinger ML, Genco RJ, Glogauer M, Goldstein M, Griffin TJ, Holmstrup P, Johnson GK, Kapila Y, Lang NP, Meyle J, Murakami S, Plemons J, Romito GA, Shapira L, Tatakis DN, Teughels W, Trombelli L, Walter C, Wimmer G, Xenoudi P, Yoshie H. Periodontal health and gingival diseases and conditions on an intact and a reduced periodontium: Consensus report of workgroup 1 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions. J Periodontol. 2018 Jun;89 Suppl 1:S74-S84. doi: 10.1002/JPER.17-0719.
PubMed 29926944Dibner C, Schibler U, Albrecht U. The mammalian circadian timing system: organization and coordination of central and peripheral clocks. Annu Rev Physiol. 2010;72:517-49. doi: 10.1146/annurev-physiol-021909-135821.
PubMed 20148687Hergenhan S, Holtkamp S, Scheiermann C. Molecular Interactions Between Components of the Circadian Clock and the Immune System. J Mol Biol. 2020 May 29;432(12):3700-3713. doi: 10.1016/j.jmb.2019.12.044. Epub 2020 Jan 10.
PubMed 31931006Hastings M, O'Neill JS, Maywood ES. Circadian clocks: regulators of endocrine and metabolic rhythms. J Endocrinol. 2007 Nov;195(2):187-98. doi: 10.1677/JOE-07-0378.
PubMed 17951531Czeisler CA, Duffy JF, Shanahan TL, Brown EN, Mitchell JF, Rimmer DW, Ronda JM, Silva EJ, Allan JS, Emens JS, Dijk DJ, Kronauer RE; New Collective Author. Stability, precision, and near-24-hour period of the human circadian pacemaker. Science. 1999 Jun 25;284(5423):2177-81. doi: 10.1126/science.284.5423.2177.
PubMed 10381883
Study at a glance
From the registry record, last updated by the sponsor on 6 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Periodontal Inflammation Is Associated With Disruption of Gingival Circadian Clock Gene and Protein Expression in Individuals With Comparable Chronotype Profiles
- ClinicalTrials.gov ID
- NCT07452783
- Acronym / sponsor ID
- PERIOCLOCK / IUCREC.2024/05.13
- Conditions
- Gingivitis, Periodontitis
- Keywords
- Circadian Rhythm, BMAL1, CLOCK, Per1, Per2, Per3, CRY1, CRY2
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 60 participants (actual)
- Lead sponsor
- Inonu UniversityUniversity, hospital or other
- Study start
- 20 Jan 2024 (actual)
- Primary completion
- 2 Mar 2025 (actual)
- Study completion
- 1 Dec 2025 (actual)
- First posted
- 5 Mar 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This observational study aims to investigate whether periodontal inflammation is associated with alterations in the expression of circadian clock-related genes and proteins in gingival tissues. Circadian rhythms regulate many biological processes, including immune responses and inflammation. Although experimental studies suggest a link between circadian disruption and periodontal disease, human data under controlled chronotype conditions are limited.
A total of 60 systemically healthy, non-smoking individuals aged 22-45 years with comparable sleep patterns (intermediate chronotype and 6-9 hours of sleep) were included. Participants were classified as periodontally healthy, gingivitis, or stage III grade B periodontitis according to established diagnostic criteria. Gingival tissue samples were collected during clinically indicated procedures within a standardized morning time window (09:00-11:00).
Gene expression levels of circadian clock components (CLOCK, BMAL1, PER1-3, CRY1-2, Rev-Erb-β, ROR-α) and inflammatory mediators (IL-1β, IL-6, TNF-α, NF-κB, IFN-γ, RANKL, OPG) were analyzed using RT-qPCR, Western blot, and ELISA techniques. Associations between molecular findings and clinical periodontal parameters were evaluated.
The study seeks to clarify whether periodontal disease itself may disrupt local circadian regulatory mechanisms in gingival tissues.
Detailed description
Circadian rhythms are generated through transcriptional-translational feedback loops involving core clock genes such as CLOCK, BMAL1, PER1-3, CRY1-2, ROR-α, and REV-ERB-β. These molecular oscillators regulate immune function, inflammatory signaling, and bone metabolism. Experimental evidence suggests that circadian dysregulation may aggravate periodontal inflammation and alveolar bone loss; however, comprehensive human data under controlled chronotype conditions remain limited.
This single-center, observational case-control study includes 60 systemically healthy, non-smoking individuals (30 males, 30 females) aged 22-45 years. Chronotype was determined using the Munich Chronotype Questionnaire, and only individuals with intermediate chronotype and self-reported sleep duration between 6 and 9 hours were included to minimize circadian variability.
Participants were classified into three groups (n=20 per group): periodontally healthy, gingivitis, and stage III grade B periodontitis according to the 2017 World Workshop criteria. Comprehensive periodontal examination included plaque index, gingival index, bleeding on probing, probing depth, and clinical attachment loss measurements. Gingival tissue biopsies were obtained during clinically indicated procedures and collected between 09:00 and 11:00 a.m. to standardize circadian timing. Samples were stored at -80°C until molecular analysis.
Total RNA was extracted from gingival tissues, and gene expression was quantified using RT-qPCR with normalization to β-actin and analysis via the 2^-ΔΔCT method. Protein expression of circadian clock components was assessed by Western blot, and inflammatory cytokine levels (IL-1β, IL-6) were quantified by ELISA. Correlation analyses were performed to evaluate associations between circadian gene expression, inflammatory mediators, and clinical periodontal parameters.
The primary objective is to determine whether periodontal inflammation is associated with disruption of gingival circadian clock gene and protein expression in individuals with comparable chronotype profiles.
Study design
- Observational model
- Case-control
- Time perspective
- Cross-sectional
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Periodontally Healthy | – | Procedure: Gingival Tissue BiopsySystemically healthy individuals with clinically healthy periodontal tissues, no attachment loss, and no radiographic bone loss. |
| Gingivitis | – | Procedure: Gingival Tissue BiopsySystemically healthy individuals presenting with gingival inflammation without clinical attachment loss or radiographic bone loss. |
| Stage III Grade B Periodontitis | – | Procedure: Gingival Tissue BiopsySystemically healthy individuals diagnosed with Stage III Grade B periodontitis according to the 2018 classification of periodontal diseases. |
Who may qualify
- Ages
- 25 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Systemically healthy adult individuals seeking care at the Department of Periodontology, Inonu University Faculty of Dentistry, were recruited. Participants were categorized into three groups based on periodontal status: periodontally healthy, gingivitis, and Stage III Grade B periodontitis according to the 2018 classification of periodontal diseases. All participants required clinically indicated periodontal procedures from which gingival tissue samples could be obtained.
Key inclusion criteria (5 listed)
- Adults aged 18 years or older
- Systemically healthy individuals
- Presence of at least 20 natural teeth
- Individuals classified as periodontally healthy, gingivitis, or Stage III Grade B periodontitis according to the 2018 classification of periodontal diseases
- Willingness to provide written informed consent
Key exclusion criteria (7 listed)
- Presence of any systemic disease affecting periodontal status (e.g., diabetes mellitus, autoimmune diseases, cardiovascular diseases)
- Use of antibiotics or anti-inflammatory medications within the previous 3 months
- Periodontal therapy within the last 6 months
- Current smokers or individuals who quit smoking within the past 5 years
- Pregnancy or lactation
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Gingival Tissue BiopsyCollection of gingival tissue samples from interproximal sites during clinically indicated periodontal procedures for molecular and protein expression analyses. | Procedure or surgery | Gingivitis, Periodontally Healthy, Stage III Grade B Periodontitis |
Primary outcome
Relative mRNA Expression Levels of Circadian Clock Genes in Gingival Tissue
Time frame: At the time of gingival tissue collection (single time point)
Quantitative assessment of BMAL1, CLOCK, PER1, PER2, PER3, CRY1, CRY2, REV-ERBβ, and ROR-α mRNA expression levels in gingival tissue samples using real-time quantitative polymerase chain reaction (RT-qPCR). Expression levels will be calculated as relative fold changes normalized to housekeeping genes and compared among periodontally healthy, gingivitis, and Stage III Grade B periodontitis groups.
3 secondary outcomes
Pro-inflammatory Cytokine Expression Levels
Time frame: At the time of tissue collection
NF-κB Expression Level
Time frame: At the time of tissue collection
Bone Metabolism Markers
Time frame: At the time of tissue collection
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Mar 2026.
- Background: PubMed 34463994Kapila YL. Oral health's inextricable connection to systemic health: Special populations bring to bear multimodal relationships and factors connecting periodontal disease to systemic diseases and conditions. Periodontol 2000. 2021 Oct;87(1):11-16. doi: 10.1111/prd.12398.
- Background: PubMed 29926944Chapple ILC, Mealey BL, Van Dyke TE, Bartold PM, Dommisch H, Eickholz P, Geisinger ML, Genco RJ, Glogauer M, Goldstein M, Griffin TJ, Holmstrup P, Johnson GK, Kapila Y, Lang NP, Meyle J, Murakami S, Plemons J, Romito GA, Shapira L, Tatakis DN, Teughels W, Trombelli L, Walter C, Wimmer G, Xenoudi P, Yoshie H. Periodontal health and gingival diseases and conditions on an intact and a reduced periodontium: Consensus report of workgroup 1 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions. J Periodontol. 2018 Jun;89 Suppl 1:S74-S84. doi: 10.1002/JPER.17-0719.
- Background: PubMed 20148687Dibner C, Schibler U, Albrecht U. The mammalian circadian timing system: organization and coordination of central and peripheral clocks. Annu Rev Physiol. 2010;72:517-49. doi: 10.1146/annurev-physiol-021909-135821.
- Background: PubMed 31931006Hergenhan S, Holtkamp S, Scheiermann C. Molecular Interactions Between Components of the Circadian Clock and the Immune System. J Mol Biol. 2020 May 29;432(12):3700-3713. doi: 10.1016/j.jmb.2019.12.044. Epub 2020 Jan 10.
- Background: PubMed 17951531Hastings M, O'Neill JS, Maywood ES. Circadian clocks: regulators of endocrine and metabolic rhythms. J Endocrinol. 2007 Nov;195(2):187-98. doi: 10.1677/JOE-07-0378.
- Background: PubMed 10381883Czeisler CA, Duffy JF, Shanahan TL, Brown EN, Mitchell JF, Rimmer DW, Ronda JM, Silva EJ, Allan JS, Emens JS, Dijk DJ, Kronauer RE; New Collective Author. Stability, precision, and near-24-hour period of the human circadian pacemaker. Science. 1999 Jun 25;284(5423):2177-81. doi: 10.1126/science.284.5423.2177.
- Individual participant dataSharing planned: Undecided. De-identified individual participant data may be made available upon reasonable request to the corresponding investigator, subject to institutional approval and ethical considerations.
Related trials for Gingivitis
Enrolling by invitation
Comparison of the Effects of Oral Hygiene Regimens on Clinical, Immunomodulatory, and Microbial Outcomes and Oral Tolerance in People With Gingivitis
Microbiome, Cytokines
Active, not recruitingPhase 3
A Study to Assess the Efficacy of Two Brushing Regimens in the Reduction of Established Dental Plaque and Gingivitis
Plaque, Gingivitis
Not yet recruiting
Effectiveness of Personalized Digital Oral Health Intervention in Patients With Fixed Orthodontic Appliances.
Oral Hygiene in Patients With Fixed Orthodontic Appliances, Dental Plaque
Not yet recruitingPhase 2
Efficacy of Thymus Vulgaris Mouthwash in the Management of Biofilm-Induced Gingivitis
Plaque-Induced Gingivitis
Not yet recruitingPhase 3
Periodontal Disease and Small Vulnerable Newborns in Rural Nepal: A Community-based Trial
Preterm Birth, Low Birth Weight
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Cuneyt A Aral, Professor, DDS, PhD study chair
Inonu University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Gingivitis and Periodontitis, run by Inonu University at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 6 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Relative mRNA Expression Levels of Circadian Clock Genes in Gingival Tissue (time frame: At the time of gingival tissue collection (single time point)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07452783, which also lists 6 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 6 Mar 2026.