Comparing Different Timings for Periodontal Re-evaluation After Non-surgical Periodontal Therapy (NSPT)

This is a prospective cohort study that aims to describe the difference in terms of percentage of closed pockets (PPD \<5 mm and no BOP) when performing the periodontal re-evaluation at 3-4, 6-8 and 12 months.

Fifty-two, ≥18-year old, otherwise healthy, periodontitis patients will be recruited at Centro di Odontoiatria, Università di Parma.

This is a prospective cohort study describing the difference in terms of percentage of closed pockets (PPD \<5 mm and no BOP) when performing the periodontal re-evaluation at 3-4, 6-8 or 12 months. The trial will follow the recommendations of the Consolidated Standards of Reporting Trials (CONSORT) statement. The study consists of 7 visits over a period of 15 months.

Visit 1 - Baseline -

* Informed consent, medical/dental history and demographics
* Record concomitant medications and smoking history
* Periodontal assessment by a blind and calibrated examiner, consisting of full mouth PPD, REC, BOP, PI, mobility and furcation involvement. PPD, REC, PI and BOP will be recorded at 6 sites per tooth.
* Standardized peri-apical x-rays for the sites with PPD≥5mm, as per standard of practice (if not already available within the previous 6 months)
* Intra-oral 3D scan
* Oral hygiene instructions and demonstration of self-performed oral hygiene measures
* PROMs questionnaires
* Saliva collection and GCF collection from the deepest pockets (maximum of 5 sites)

Visit 2 and 3 - NSPT - (and extra visit 3.1 and 3.2 if needed) (within 60 days from baseline)

* Update medical/dental history and record adverse events and/or concomitant medications
* NSPT, consisting in the careful removal of hard and soft deposits with ultrasonic instruments at infected sites performed by an experienced clinician following the principles of minimally invasive non-surgical therapy (MINST). A quadrant approach will be adopted and it will be left to the discretion of the clinician to choose whether to instrument 1 or 2 quadrants at a time and the length of session visits. Hence, 2 to 4 sessions of NSPT with an interval of 1 week between each other will be performed. During NSPT, teeth considered hopeless will be extracted as per standard of practice.
* Reinforcement of oral hygiene instructions
* PROMs questionnaires

Extra visits outside the study protocol may be arranged in case the patients need extractions or other dental treatments besides NSPT.

Visit 4 (4-6 weeks from the end of NSPT)

* Update medical/dental history and record adverse events and/or concomitant medications
* Visual inspection of signs of inflammation and plaque
* Supragingival polish and reinforcement of oral hygiene instructions
* PROMs questionnaires
* Intra-oral 3D scan

Visit 5 (3-4 months from the end of NSPT)

* Update medical/dental history and record adverse events and/or concomitant medications
* Periodontal assessment by a blind and calibrated examiner, consisting of full mouth PPD, REC, BOP, PI, mobility and furcation involvement. PPD, REC, PI and BOP will be recorded at 6 sites per tooth.
* PROMs questionnaires
* Intra-oral 3D scan
* Saliva collection and GCF collection from the same sites identified at baseline
* Supragingival polish and reinforcement of oral hygiene instructions

Visit 6 (6-8 months from the end of NSPT)

* Update medical/dental history and record adverse events and/or concomitant medications
* Periodontal assessment by a blind and calibrated examiner, consisting of full mouth PPD, REC, BOP, PI, mobility and furcation involvement. PPD, REC, PI and BOP will be recorded at 6 sites per tooth.
* PROMs questionnaires
* Intra-oral 3D scan
* Saliva collection and GCF collection from the same sites identified at baseline
* Supragingival polish and reinforcement of oral hygiene instructions

Visit 7 (12 months ± 14 days from the end of NSPT)

* Update medical/dental history and record adverse events and/or concomitant medications
* Periodontal assessment by a blind and calibrated examiner, consisting of full mouth PPD, REC, BOP, PI, mobility and furcation involvement. PPD, REC, PI and BOP will be recorded at 6 sites per tooth.
* PROMs questionnaires
* Intra-oral 3D scan
* Standardized peri-apical x-rays
* Saliva collection and GCF collection from the same sites identified at baseline
* Supragingival polish and reinforcement of oral hygiene instructions

Photos and videos may be taken/recorded in any of the study visits for documentation purposes. The subject will not be identifiable from those photos/videos.

Eligibility Criteria:
Inclusion Criteria:

* Systemically healthy males and females ≥18 years old
* Willingness to read and sign a copy of the Informed Consent Form after reading the Patient Information Sheet, and after the nature of the study has been fully explained
* Clinical evidence of periodontitis, defined as the presence of interdental clinical attachment loss detectable at ≥2 non-adjacent teeth or buccal or oral clinical attachment loss ≥3mm with pocketing \>3 mm detectable at ≥2 teeth (Tonetti et al., 2018)
* Not having received subgingival instrumentation within the previous 12 months

Exclusion Criteria:

* Medical history that includes serious medical conditions or transmittable diseases (e.g. serious cardiovascular disease, organ transplant, renal failure, AIDS, viral etc.).
* Antibiotic, anti-inflammatory or anticoagulant therapy during the month preceding the baseline exam.
* In treatment with drugs that induce gingival overgrowth
* History of conditions requiring prophylactic antibiotic coverage prior to invasive dental procedures
* History of alcohol or drug abuse.
* Self-reported pregnancy or lactation (this criterion is due to oral tissue changes related to pregnancy and nursing, which can affect interpretation of study results).
* Other severe acute or chronic medical or psychiatric condition or laboratory abnormality that may increase the risk associated with trial participation or investigational product administration or may interfere with the interpretation of trial results and, in the judgement of the investigator, would make the subject inappropriate for entry into this trial.