Echo Doppler Ultrasonographic Characterization of Healthy and Diseased Implant Sites

Abstract

The study of peri-implant diseases is constantly evolving, from the best practices for detecting mucositis to treating mucositis to return the patient to peri-implant health and the interventions that can be used to treat peri-implantitis. Probing dental implants is the current standard of care for early diagnosis, prevention, and intervention. Ultrasonography in dentistry is an innovative and non-invasive tool that can be useful in the early detection of peri-implant disease to measure tissue perfusion. The pilot case-control study aimed to assess ultrasonographic features and doppler tissue perfusion at healthy implants (HE) and sites diagnosed with peri-implant mucositis (PM); changes within clinical, ultrasonographic, and patient-reported outcomes were assessed after non-surgical therapy. Twenty (20) patients receiving treatment at Harvard Dental Center with two non-adjacent implants diagnosed as HE and PM were included in the present study. The peri-implant region of interest was scanned using the ultrasound before non-surgical therapy at T0 and four weeks after non-surgical treatment at T1. Clinical measurements such as probing depth (PD), keratinized mucosa width (KMW), and peri-implant soft tissue dehiscence (PSTD) of the healthy and diseased implants were assessed. Tissue perfusion, mucosal thickness (MT), buccal bone distance (BBD), buccal bone thickness (BBT), supracrestal tissue height (STH), and mesial and distal papilla height (PH) at the healthy and diseased implants at the midfacial and interproximal was measured at both time points. Non-surgical therapy was performed during the same visit at the diseased implant site, and oral hygiene techniques were reviewed. Thirteen of the twenty diseased implant sites showed complete resolution of the inflammatory condition at the re-evaluation visit. A reduction of mucosal thickness was observed in its coronal portion, while no changes were observed in the most apical areas. PM sites displayed an ultrasonographic feature of an isolated darker area, analogous to a radiolucent area on an x-ray, adjacent to the junctional epithelial surface of the peri-implant mucosa, termed a hypoechoic supracrestal area/lesion (HSA). Without BOP on the midfacial aspect, 19 out of 20 (95%) ultrasound scans did not exhibit HSA. The vertical extension of the HSA (in a corona-apical dimension) was 5.75 mm at baseline and 3.2 mm at the re-evaluation. At the same time, the area of the HSA was 4.94 mm2 at baseline and 2.61 mm2 at the re-evaluation visit. Color Doppler Velocity and Power Doppler were significantly increased in PM sites compared to the HE group (p.01), and their magnitude was correlated to the area of the HSA (p.05). Echo-Doppler ultrasonography is a valuable tool for the characterization of healthy and diseased implant sites in a non-invasive manner. Ultrasonographic outcomes, such as the presence/absence of a “lesion” (HSA) and Doppler tissue perfusion, correlated with the clinical diagnosis of health vs. disease while providing additional information that may be associated with the severity of the condition, the likelihood of resolution, and diseased progression over time. Future studies with longer follow-ups are needed to validate these preliminary findings.