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1 - y e a r s t u d y o f n o n s u b m e r g e d i m p l a n t s Consensus Conference)14 was specifically deter- mined by an experienced university clinician following rigorous criteria aimed at best clinical practice (judgmental allocation).15 The following groups were defined: – Immediate post-extraction implant group (type 1 for ITI):14 placement of the implant into the fresh extraction socket immediately after extraction of a tooth affected by chronic periapical disease or of a seriously damaged, hopeless tooth. Only chronic periapical lesions were present and identified by periapical radiolucency. – Early implant group (type 2 for ITI):14 place- ment of the implant in healed bone after 8–12 weeks after extraction of a tooth affected by an acute periapical lesion and/or abscess, pus and clinical symptoms. – Delayed implant group (type 4 for ITI):14 place- ment of the implant in edentulous mature bone 10–12 months after tooth extraction. P r e o p e r a t i v e p r o t o c o l The day before surgery, all of the patients were subjected to a preventive pharmacological treat- ment consisting of 1 g of amoxicillin/clavulanic acid (Augmentin, GlaxoSmithKline, Brentford, U.K.; 1 tablet at 24 and 12 h before the surgery) and a 0.12% chlorhexidine digluconate gel (Corsodyl Gel, GlaxoSmithKline; 3 applications per day). Antibiotic administration was con- tinued for 5 days postoperatively. I m p l a n t s u r g e r y Implant surgeries were conducted by the same operator (C.P.) under local anesthesia with 30 mg/mL of mepivacaine hydrochloride (Carboplyina, Dentsply Italia, Rome, Italy) in sterile conditions. All of the implants were placed in 1-stage surgical procedures. No flaps were raised and no surgical guides were used. A pilot drill of 1.2 mm in diameter was used to mark the position, angle and depth. The drill passed through the mucosa (nonsubmerged), cor- tical bone and cancellous bone at 225 rpm. A series of calibrated drills working at 225 rpm were used to create a site of adequate depth and diameter. Prama implants, characterized by a 3 mm transmucosal machined neck with a hyperbolic profile (as illustrated by the environmental scan- ning electron microscopy image in Fig. 1) were inserted to keep the blasted surface at cortical bone level and the smooth machined neck surface 1–3 mm above the gingival level, accord- ing to the transmucosal technique.16 No sutures were placed. A surgical dressing (COE-PAK, GC America, Alsip, Ill., U.S.) was applied to the implant site and kept in position for 5–7 days. P o s t o p e r a t i v e p r o c e d u r e s Patients were instructed to follow a soft diet regime for 1 week, to rinse 3 times per day with a 0.12% chlorhexidine mouthwash for 3 weeks and to perform oral hygiene on the COE-PAK using a normal-medium-hardness toothbrush for the first week and for 2 weeks after removal of the surgical dressing. Thereafter, conven- tional brushing and flossing were permitted. P r o s t h e t i c r e s t o r a t i o n Three months after implant insertion, impressions using polyether materials (Permadyne and Garant, 3M ESPE, St. Paul, Minn., U.S.) were taken using customized resin trays (pickup impression tech- nique). Gypsum model casts were obtained and provisional resin crowns were carefully designed to keep the crown margins at gingival level with the finishing line on the implant hyperbolic neck. Customized titanium abutments were screwed in after 5–7 days. All of the resin crowns were positioned with temporary cement (Temp Bond, Kerr, Scafati, Italy) for initial prosthetic restoration. In this way, the implant–abutment connection was internal to the crowns. Abut- ments were intended to increase the retention of the cement–crown monobloc. Twenty days later, definitive prosthetic metal–ceramic crowns were positioned and fixed with a polycarboxylate cement (Heraeus Kulzer, Hanau, Germany). Definitive crowns were also prepared according to the BOPT so that all metal and ceramic finishing lines corresponded to the implant hyperbolic neck. Fitting of the metal was gently and carefully done to create a mechanical metal–metal friction. Two experienced prostho- dontists (C.P. and L.M.) performed all of the pros- thetic procedures. Great attention was given to avoiding any cement excess around the resto- rations. F o l l o w - u p i m p l a n t e v a l u a t i o n Active periodontal therapy consisting of moti- vation, instruction in oral hygiene practice, scaling and root planing was performed until no or modest periodontal disease was present. 34 Volume 3 | Issue 4/2017 Journal of Oral Science & Rehabilitation