An interventional study of Nonsurgical periodontal treatment in Periodontal Diseases Inflammation, Periodontal Disease and Periodontal Attachment Loss, sponsored by University of Ljubljana. Completed at 1 site in Slovenia. Open to participants aged 18 Years to 75 Years. Per ClinicalTrials.gov, last updated 2026-11-03.
Sponsored by University of Ljubljana · Not applicable, Interventional, and Treatment
This single-centre, randomized split-mouth trial assessed clinical periodontal changes and acute systemic inflammatory responses when supra- and subgingival instrumentation was performed concurrently with oral hygiene instruction or after 90 days of oral hygiene reinforcement. Ten adults with periodontitis participated. One upper and one lower quadrant were randomly allocated to immediate instrumentation, while remaining quadrants received oral hygiene instruction and were instrumented at day 90. Clinical outcomes were evaluated at baseline, day 90 and day 180. High-sensitivity C-reactive protein was sampled before and 24 hours after each instrumentation session.
Periodontitis is a chronic inflammatory disease characterized by the progressive destruction of tooth-supporting tissues. Effective periodontal treatment requires both adequate supragingival plaque control and professional supra- and subgingival instrumentation. Although oral hygiene improvement is an essential component of periodontal therapy, the influence of its timing relative to subgingival instrumentation on clinical treatment outcomes and the acute systemic inflammatory response remains insufficiently understood.
The aim of this single-centre, randomized, controlled, split-mouth clinical trial was to investigate whether improving oral hygiene before periodontal instrumentation, compared with initiating oral hygiene improvement at the time of instrumentation, influences clinical periodontal outcomes and the acute systemic inflammatory response, assessed by changes in serum high-sensitivity C-reactive protein (hs-CRP) concentrations 24 hours after treatment.
Ten adults diagnosed with generalized periodontitis (Stage II or III, Grade C) were enrolled at the Department of Oral Medicine and Periodontology, University Medical Centre Ljubljana, Slovenia. All participants underwent a comprehensive periodontal examination, including measurements of probing pocket depth (PPD), clinical attachment level (CAL), gingival recession, bleeding on probing (BOP), and full-mouth plaque score (FMPS). Intraoral three-dimensional scans were obtained to assess changes in gingival soft-tissue morphology.
A computer-generated randomization procedure was used to allocate one maxillary and one mandibular quadrant in each participant to immediate periodontal instrumentation. These quadrants received supra- and subgingival instrumentation at baseline, together with individualized oral hygiene instruction and motivation. The remaining two quadrants initially received oral hygiene instruction without periodontal instrumentation. Participants were instructed in appropriate toothbrushing and interdental cleaning techniques and attended follow-up appointments for plaque assessment and reinforcement of oral hygiene practices.
At day 90, a comprehensive periodontal examination and intraoral scan were repeated. The previously untreated quadrants then underwent supra- and subgingival instrumentation, following 90 days of oral hygiene improvement. Additional follow-up visits were performed 1, 7, 14, and 30 days after each instrumentation session. The final periodontal examination and intraoral scan were conducted at day 180, corresponding to 90 days after instrumentation of the second group of quadrants.
Venous blood samples were collected immediately before and 24 hours after each instrumentation session to determine serum hs-CRP concentrations. These measurements were used to assess the acute systemic inflammatory response associated with periodontal instrumentation performed at different stages of oral hygiene improvement.
Clinical periodontal outcomes included changes in PPD, CAL, BOP, and plaque scores. Additional analyses evaluated treatment responses according to baseline periodontal pocket depth and assessed three-dimensional gingival soft-tissue changes using digital surface and volumetric comparisons.
The split-mouth design enabled comparisons between treatment approaches within the same participants, thereby reducing the influence of interindividual variability. The study was designed to provide preliminary evidence regarding the influence of oral hygiene improvement before subgingival instrumentation on periodontal healing and the acute systemic inflammatory response.
The study received approval from the National Medical Ethics Committee of the Republic of Slovenia (Approval No. 0120-417/2023/3). Written informed consent was obtained from all participants.
867 studies on the registry are indexed under Periodontal Diseases; 189 are open to participants now.
This study's enrollment of 10 is below the median of 45 across 557 interventional studies indexed under Periodontal Diseases.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Detailed oral hygiene instructions followed by two stage complete oral disinfection
Procedure: Nonsurgical periodontal treatment
All participants received individualized oral hygiene instructions and motivation at baseline. Supra- and subgingival instrumentation was performed in one randomly selected maxillary and one randomly selected mandibular quadrant at baseline. The remaining quadrants underwent the same instrumentation at day 90. Instrumentation was performed using ultrasonic instruments (PiezoLED, KaVo) and hand instruments (Gracey curettes, Hu-Friedy, USA). Full-Mouth Plaque Scores (FMPS) were assessed at follow-up visits on days 1, 7, 14, and 30 after each instrumentation session, and oral hygiene instructions were reinforced as needed to achieve an FMPS below 20% before instrumentation at day 90. Venous blood samples were collected immediately before and 24 hours after each instrumentation session (at baseline and day 90) to measure serum high-sensitivity C-reactive protein (hs-CRP). Three-dimensional (3D) intraoral scans were obtained at baseline, day 90, and day 180.
Probing pocket depth (PPD)
Probing pocket depth measured using manual probe at 6 sites around each tooth. Unit: millimeters
Time frame: At baseline
Probing pocket depth (PPD)
Probing pocket depth measured using manual probe at 6 sites around each tooth. Unit: millimeters
Time frame: 90 days after first intervention
Probing pocket depth (PPD)
Probing pocket depth measured using manual probe at 6 sites around each tooth. Unit: millimeters
Time frame: 180 days after first intervention (90 days after second intervention)
Bleeding on probing (BOP)
Yes/No after probing pocket depth measurement 6 sites around each tooth. Unit: % (bleeding sites/all sites)
Time frame: At baseline
Bleeding on probing (BOP)
Yes/No after probing pocket depth measurement 6 sites around each tooth. Unit: % (bleeding sites/all sites)
Time frame: 90 days after first intervention
Bleeding on probing (BOP)
Yes/No after probing pocket depth measurement 6 sites around each tooth. Unit: % (bleeding sites/all sites)
Time frame: 180 days after first intervention (90 days after second intervention)
Clinical attachment level (CAL)
This is the measurement of the position of the soft tissue attachment in relation to the cemento-enamel junction (CEJ). Two measurements are used to calculate the CAL: the probing depth and the distance from the gingival margin to the CEJ. Unit: millimeters
Time frame: At baseline
Clinical attachment level (CAL)
This is the measurement of the position of the soft tissue attachment in relation to the cemento-enamel junction (CEJ). Two measurements are used to calculate the CAL: the probing depth and the distance from the gingival margin to the CEJ. Unit: millimeters
Time frame: 90 days after first intervention
Clinical attachment level (CAL)
This is the measurement of the position of the soft tissue attachment in relation to the cemento-enamel junction (CEJ). Two measurements are used to calculate the CAL: the probing depth and the distance from the gingival margin to the CEJ. Unit: millimeters
Time frame: 180 days after first intervention (90 days after second intervention)
Plaque index (PI)
Yes/No at six sites around each tooth. Unit: % (sites with plaque/all sites)
Time frame: At baseline
Plaque index (PI)
Yes/No at six sites around each tooth. Unit: % (sites with plaque/all sites)
Time frame: 90 days after first intervention
Plaque index (PI)
Yes/No at six sites around each tooth. Unit: % (sites with plaque/all sites)
Time frame: 180 days after first intervention (90 days after second intervention)
Change in serum hs-CRP from pre-instrumentation to 24 hours after
The absolute change in hs-CRP concentration (24-hour post-instrumentation value minus the pre-instrumentation value), expressed in mg/L.
Time frame: Immediately before and 24 hours after baseline instrumentation
Change in serum hs-CRP from pre-instrumentation to 24 hours after
The absolute change in hs-CRP concentration (24-hour post-instrumentation value minus the pre-instrumentation value), expressed in mg/L.
Time frame: Immediately before and 24 hours after instrumentation at day 90
Digital gingival surface area (mm²) deviations
Digital models were superimposed to evaluate gingival surface deviations over time. Changes in gingival surface area were quantified in square millimetres (mm²) and compared between quadrants
Time frame: 90 days after first intervention
Digital gingival surface area (mm²) deviations
Digital models were superimposed to evaluate gingival surface deviations over time. Changes in gingival surface area were quantified in square millimetres (mm²) and compared between quadrants
Time frame: 180 days after first intervention
Digital gingival volume (mm³) deviations
Digital models were superimposed to evaluate gingival surface deviations over time. Changes in gingival volume were quantified in cubic millimetres (mm³) and compared between quadrants
Time frame: 90 days after first intervention
Digital gingival volume (mm³) deviations
Digital models were superimposed to evaluate gingival surface deviations over time. Changes in gingival volume were quantified in cubic millimetres (mm³) and compared between quadrants
Time frame: 180 days after first intervention
Plan to share: No — All Research data will be available or shared on individual request. Example: conducting Meta-Analysis.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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University of Ljubljana