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ePaper created 2017-03-17, 11:08:54 | version 1.38.0
P h y s i o l o g i c a l b o n e r e m o d e l i n g o n O s s t e m i m p l a n t s computed tomography (CBCT) scans, and model casts were produced for all of the patients, for initial screening and case evaluation. Before implant placement, all of the patients received a single dose of an antibiotic (2 g of amoxicillin or 600 mg of clindamycin if allergic to penicillin). Prior to the start of surgery, the patients rinsed with 0.2% chlorhexidine for 1 min. The patients received Osstem TSIII bone level implants with a rough surface (Ra of 2.5~3.0 μm) sandblasted with alumina and acid-etched and featuring an internal hex and 11° conical connection. Implant placement was performed using either comput- er-guided template-assisted implant placement or conventional freehand surgery. Most of the implants were placed according to the drilling protocol recommended by the manufacturer. In the case of immediate loading, post- extractive implants and poor bone quality, the drilling pro- tocol was customized (Table 1). Surgical protocols included placement in completely or partially edentulous healed ridges with or without bone grafting, as well as in fresh extraction sockets using a flapless or a flap ap- proach. A flapless approach was planned in the case of post-extractive implants or in a healed site, depending on the width of the available keratinized mucosa. In cases of ridge atrophy, defined as a bone height of < 7.0 mm and/or bone width of < 4.5 mm, implant placement was per- formed simultaneously with guided bone regen- eration (GBR). Otherwise, in cases of severe ridge atrophy, implant placement was per- formed six months after bone regene ration. Sinus lift procedures were performed using the conventional lateral window technique or by a less invasive transcrestal sinus floor elevation (Crestal Approach Sinus KIT, CAS-KIT, Osstem) in the case of a residual alveolar crest of at least 3 mm (maximum of 8 mm) in height and 6 mm in width distal to the canine, measured on a CBCT scan. In all reconstructive cases, the bone graft material was based on auto genous bone, combined with synthetic hydroxyapatite en- riched with magnesium (SINTlife, Finceramica, Faenza, Italy) or with beta- tricalcium phosphate (Q-Oss+, Osstem). A resorbable cross-linked collagen membrane (OssGuide, Osstem) was used to protect the graft material during healing in the case of GBR or the lateral window ap- proach. In the case of immediate post-extractive im- plants, residual teeth were extracted as atrau- matically as possible. Implant insertion was then planned along the palatal socket wall, about 1.5 mm below the buccal alveolar crest. The residual socket was grafted with corticocancel- lous heterologous bone, with a graft particle size of 250–1,000 μm (OsteoBiol Gen-Os, Tecnoss, Giaveno, Italy). In the case of delayed implants, socket preservation was performed with the same procedure and the implant was placed four months after healing. Loading protocols varied based on implant stability and/or individual case requirements. Immediate loading (within 48 h of implant place- ment) was performed in the case of an implant stability of at least 35 N cm and at the patient’s request. Titanium temporary abutments or titanium or zirconia definitive abutments were screwed directly on to the implants or the inter- mediate abutments (straight or angulated multi-abutments, Osstem) with prosthetic screws tightened to 15 N cm on the day of surgery. Straight or angled multi-abutments (Osstem) were used in the case of multiunit res- torations and screw-retained prostheses and/or when there was the need to change the depth or the angle of the implant. Prefabricated, screw-re- tained or cemented temporary acrylic resto- rations were trimmed and polished chairside. Partially edentulous patients received nonocclu- sal temporary restorations. Multiple implants received splinted, metal-reinforced temporary restorations with centric contact and group func- tion, but without any cantilever. If needed, flaps were closed around the abutments. Otherwise, in the case of a bone augmentation procedure or post-extractive implants, a conventional or de- layed loading protocol (three to six months after implant placement) was adopted.17 After implant placement, all of the patients received oral and written recommendations on medication, oral hygiene maintenance and diet. Postoperative antibiotic therapy (1 g of amoxi- cillin or 300 mg of clindamycin), administered every 12 h for six days, was limited to cases with immediate socket sites, bone grafting or sinus procedures. Analgesics (500 mg of paracetamol plus 30 mg of codeine, or 600 mg of ibuprofen) were administered as needed. Final restorations were delivered between eight (single or partial crowns and overdentures) and twenty weeks (full arches). Final resto- rations were either screw-retained or cemented. Cemen ted restorations were delivered on either stock or customized CAD/CAM abutments. All of the restorations (metal and zirconia) were cemented using a glass ionomer cement (Ketac Cem, 3M ESPE, Neuss, Germany). Any cement 70 Volume 3 | Issue 1/2017 Journal of Oral Science & Rehabilitation