Comparison of Bone Formation According to Different Maxillary Sinus Width: a Multicenter Prospective Study.

Material and Methods Study protocol This study was designed as a multicenter prospective study following STROBE (STrengthening the Reporting of Observational studies in Epidemiology) guidelines. All procedures were performed in strict accordance with the recommendations of the Declaration of Helsinki as revised in Fortaleza for investigations with human subjects. The study protocol had been approved by the relevant ethical committee (Comitato Etico Calabria-Sezione Area Nord n. 55/2016). Patients, after being thoroughly informed about the study protocol, the treatment, its alternatives and any potential risk, signed a written informed consent for the participation in the study and authorized the use of their data for research purposes.

Any patient with Kennedy class II partial edentulism requiring unilateral sinus floor elevation for the placement of two not adjacent dental implants supporting a fixed partial prosthesis was eligible for entering this study.

Pre-surgical phase Patients recruited in the present study underwent a careful clinical examination, including assessment of periodontal conditions (probing and periapical radiographs), evaluation of available bone volume in the edentulous areas on cone beam computed tomography and analysis of occlusal relationships (diagnostic wax-up). A surgical resin guide was manufactured by duplicating the diagnostic wax-up.

All patients received professional mechanical tooth cleaning and periodontal debridement one week prior to surgery and were prescribed with chlorhexidine digluconate 0.2% mouthwash twice a day.

Surgical procedure All patients underwent antibiotic prophylaxis (2 g single-dose amoxicillin one hour before surgery). After performing local anaesthesia (articaine 4% with epinephrine 1:100.000) and elevating a full-thickness flap, the surgical guide was placed in position and an antrostomy was created by consuming the lateral wall of the maxillary sinus with ultrasonic instrumentation in the area between the two planned implant sites. The sinus membrane was then carefully elevated and, after checking its integrity with visual inspection and Valsalva maneuver, the subantral space was filled with a composite graft in granules [50% cortico-cancellous porcine graft (Gen-Os, Tecnoss, Pianezza, Italy) - 50% synthetic nano-hydroxyapatite (Fisiograft Bone, Ghimas, Casalecchio di Reno, Italy)]. A resorbable bovine collagen membrane (Bio-Gide, Geistlich, Wolhusen, Switzerland) fixed with two pins was placed to cover the lateral antrostomy and flaps were sutured with Sentineri sutures and single stitches using synthetic monofilament. Patients were prescribed with antibiotics for 4 days (amoxicillin 1 g three times a day) and NSAID (ibuprofen 600 mg), when needed. Sutures were removed after 10 days.