Hybrid surface dental implant

moderately rough surface implant

Under local anaesthesia, full-thickness mucoperiosteal flaps were elevated, the alveolar ridge measured, and a proper implant dimension (3.75 mm and 4.25 mm diameter; 8 mm, 10 mm and 11.5 mm length) and position selected. After site preparation, each patient was randomly allocated to the test or the control group. Patients in the test group received a modified implant design with the coronal third presenting a machined surface (hybrid surface (HS) group), while in the control group the same implant design with a titanium rough surface up to the implant shoulder was used (rough surface (RS) group). Implants were placed 1 mm sub-crestally. In the case of dehiscence or fenestrations around the implant, the patient was excluded from the study. Once inserted, healing abutments (ranging between 3 -5 mm) were placed, and flaps sutured around the abutments to allow for a transmucosal healing.

Radiographic marginal bone levels (bone loss) are defined as the distance between the bone crest and the implant shoulder at mesial and distal sites.

For standardization of periapical radiographs the same film holder-beam aiming device will be applied (Rinn System) and silicone custom-made bite blocks will be used to improve reproducible repositioning. All digital radiographs will be evaluated by one calibrated and trained researcher (BS) using a software (AutoCAD® Autodesk ®, California, USA) that allows to calibrate the distances using the known implant length.

Clinical measurements will be performed at six sites per implant of i) probing depth (PD), ii) marginal mucosa recession assessed as length of the implant crown (CLI; distance from the mucosal margin to the oclusal surface at the mid buccal point), iii) bleeding on probing (BoP) and iv) plaque scores (PI). Finally, peri-implant mucositis, defined as the presence of profuse BoP.