Longitudinal Evaluation of Several Modalities of Treatment of Peri-implantitis: 5 to 23 Years Follow-up

To evaluate the peri-implant conditions of patients undergoing different surgical and non-surgical techniques, associated or not with regenerative therapies after long periods of time (between 5 and 23 years)

3. MATERIAL AND METHODS

3.1. Experimental design This retrospective study will evaluate the peri-implant conditions of patients with peri-implantitis treated at the UnG Clinic using various types of treatments. To this end, participants will be selected from the UnG graduate clinic who received some type of treatment (surgical or non-surgical) until 2021. Participants selected for the study must sign the Informed Consent Form (ICF) after verbal and written explanation of the project. Subjects will receive oral hygiene instruction and professional prophylaxis prior to clinical examinations.

3.2. Sample selection This clinical study will be submitted for approval by the Ethics Committee of the University of Guarulhos (CEP-UnG). Subjects (minimum of 50 and maximum of 300) will be recruited and evaluated at the Implantology clinic of Guarulhos University. This sample was obtained based on the power test so that the study presented a power of around 80%, and NCI and bone loss were considered primary variables.

3.3. Inclusion criteria The sample included 300 systemically healthy individuals, over 18 years of age, who received some type of treatment (surgical or non-surgical) for peri-implantitis, associated or not with systemic antibiotic therapy.

3.4. Sample exclusion criteria Individuals who have lost the implants after some peri-implant therapy;' have undergone periodontal treatment for at least 6 months prior to the start of the study.

Clinical examinations A single, trained and calibrated examiner will perform all clinical examinations. The examiner will be trained and calibrated before and during the study in order to achieve maximum reproducibility in measurements. The methodology to be used for intra-examiner calibration will be the one recommended by Araujo et al. 2003, in which the standard error of measurement for continuous periodontal clinical parameters is evaluated. For the other clinical variables, the mean level of agreement between the examiners will be determined and considered satisfactory when the value is greater than 90% (Kappa test).

Clinical measures

The following parameters will be recorded at six sites per implant using a periodontal probe North Carolina:

1. Plate index: 0 = absence of plaque; 1 = separate patches of plaque at the cervical margin; 2 = a thin, continuous band of plaque [up to 1 mm] at the cervical margin of the tooth; 3 = strip of plaque greater than 1 mm, but covering less than 1/3 of the tooth crown; 4 = plaque that covers at least 1/3 but less than 2/3 of the tooth's crown; 5 = plate covering 2/3 or more of the tooth's crown).
2. Gingival index : 0 = absence of inflammation; 1 = mild inflammation change in color and little change in texture; 2 = moderate inflammation - tempered glasses, redness, edema and hypertrophy; 3 = severe inflammation - marked redness and hyperplasia.
3. Bleeding on probing: 0 = absence; 1 = presence.
4. Suppuration: 0 = absence; 1 = presence.
5. Probing depth: distance (mm) from the peri-implant mucosal margin to the most apical portion of the peri-implant pocket.
6. Relative attachment level: distance (mm) from the implant shoulder to the most apical portion of the peri-implant pocket.
7. Keratinized tissue height : vertical distance (mm) measured from the mucogingival line to the peri-implant margin in the center of the buccal face of the implant.
8. Keratinized tissue thickness 1: measured in the center of the buccal surface of the ridge, at the midpoint between the mucogingival line and the top of the ridge.
9. Mesial and distal keratinized tissue thickness 2: measured over the ridge (mesial and distal of the implant) when the crown can be removed.
10. Evaluation of the biotype of peri-implant tissue: thin or thick, according to the visualization of the periodontal probe through the peri-implant tissue.

Screw-retained implant crowns will be removed to observe clinical records, while cemented crowns will not be removed.

Radiographic measurements As a way of evaluating the stability of bone tissue, the interproximal level of the bone crest will be measured by means of periapical radiographs. After the radiographic takes, the radiographs will be scanned and the distance in millimeters from the interproximal bone crest to the base of the implant will be evaluated.