To study the morphology of the peri-implant defects using cone-beam computed tomography based on a priori case definition of peri-implantitis (≥3mm of radiographic bone loss + inflammatory clinical parameters)

Diagnosis of peri-implantitis requires:

• Presence of bleeding and/or suppuration on gentle probing.
• Increased probing depth compared to previous examinations.
• Presence of bone loss beyond crestal bone level changes resulting from initial bone remodeling.

In the absence of previous examination data diagnosis of peri-implantitis can be based on the combination of:

• Presence of bleeding and/or suppuration on gentle probing.
• Probing depths of ≥6 mm.
• Bone levels ≥3 mm apical of the most coronal portion of the intraosseous part of the implant.

Nowadays, several radiographic techniques are available to investigate the peri-implant bone morphology by two-dimensional radiographs such as panoramic radiography and intraoral radiography, or three-dimensional techniques such as computer tomography and cone beam computer tomography (CBCT) (Harris et al. 2012). CBCT provides high-contrast 3D visualization of bone beds; however, artifacts caused by the metallic character of implants could disguise information around implants. The diagnostic outcomes of CBCT imaging of peri-implant bone loss have been related to the type of study and defect morphology (Pelekos et al., 2018). The ex vivo studies (cadaver models), considering sensitivity and specificity reported good values for both circumferential and infrabony defects but lower for dehiscences (de-Azevedo-Vaz et al., 2013, Kamburoglu et al., 2013). Contrastingly, CBCT imaging for defect analysis in animal studies showed positive correlation with histology but tend to overestimate (Fienitz et al., 2012, Golubovic et al., 2012) or underestimate (Corpas Ldos et al., 2011, Ritter et al., 2014) the size of the defect. This variability in the measurement is mainly dependent on the different configuration, location or size of the defect. and also by the scattering, beam hardening artifacts, energy settings, exposure time, field of view.

Hence, it is aimed at assessing the morphology of the peri-implant defects using CBCT

Inclusion Criteria:

• Male or female patients between 18 and 80 years of age
• Partial/complete edentulism missing one or more teeth and having it restored with implant-supported prosthesis
• No antibiotic in the last 2 months previous to examination
• >3 year after prosthesis delivery

Exclusion Criteria:

• Uncontrolled systemic disease
• Cemented-retained restorations
• Patients with uncontrolled/active periodontal disease in need of periodontal treatment
• Pregnant patients
• Zygomatic implants
• Implants placed in regenerated/augmented bone
• Patients taking medications known to modify bone metabolism or known to have degenerative diseases of bone (hyperparathyroidism, osteoporosis), vitamin D, patients who had taken antibiotics, NSAIDS or corticosteroids for more than two weeks in the past 3 months before examination

Healthy partially/complete edentulous having previously received screw-retained implants for oral rehabilitation for ≥3 years.