Please activate JavaScript!
Please install Adobe Flash Player, click here for download

Journal of Oral Science & Rehabilitation No. 2, 2016

Journal of Oral Science & Rehabilitation Volume 2 | Issue 2/2016 19 T h r e e - y e a r r e s u l t s o f A l l - o n - 4 i n d a i l y p r a c t i c e S u r g i c a l p r o t o c o l An antibiotic (2g of amoxicillin and clavulanic acid or 600mg clindamycin if allergic to penicil- lin) was administered 1 h prior to surgery and continued for six days (1g amoxicillin and clavu- lanic acid or 300 mg clindamycin b.i.d.) after surgery. Local anesthesia was induced using a 4% articaine solution with 1:100,000 epineph- rine (Ubistesin; 3M Italia, Milan, Italy). Implants were placed in the planned anatomical sites ei- ther conventionally or using a fully guided ap- proach. A flapless or a flap approach was per- formed in order to maintain an adequate residual band of keratinized mucosa around the implants. When the alveolar crest was too thin (knife edge) to place the implant, the alveolar crest was remodeled using piezoelectric bone surgery under copious irrigation with sterile sa- line to obtain a flat bony crest. Each patient re- ceived four NobelSpeedy Groovy implants (No- bel Biocare), featuring a flat-to-flat matched implant-abutment interface with a 0.7mm tall external hexagonal prosthetic connection and a rough, highly crystalline and phosphate-en- riched titanium oxide surface (TiUnite, Nobel Biocare).All ofthe implantswere placed accord- ing to the surgical and prosthetic protocols rec- ommended by the manufacturer (IFU 73494 Manual 2/All-on-4 and IFU 71286), with no de- viations from the original protocol. The drilling sequence was chosen according to the manu- facturer’s instructions in relation to the bone quality, achieving an insertion torque at implant placement ranging from 35 to 45 N cm in the mandible or from 35 to 55Ncm in the maxilla, measured using a surgical unit (OsseoCare Pro Drill Motor Set, Nobel Biocare). In the post-ex- traction sites, the gaps between the implants andthesurroundingsocketwallswerefilledwith 0.25–1 mm granules of deproteinized bovine bone (Geistlich Bio-Oss orGeistlich Bio-Oss Col- lagen, Geistlich Pharma, Wolhusen, Switzer- land), hydrated using the patient’s blood mixed with antibiotic solution (Rifocin 250mg/10mL, Sanofi-aventis, Milan, Italy). Seventeen- or thirty-degree angled mul- ti-unit abutments (Nobel Biocare) were imme- diately connected to the distal implants for bet- terorientation ofthe screwaccess hole. Straight multi-unit abutments (NobelBiocare)were used in the anterior implants if needed. A prefabricated screw-retained acrylic resin provisional restoration without any cantilever was delivered immediately after surgery (Figs. 3–5). All of the patients received oral and writtenrecommendationsregardingmedication, oralhygiene maintenance and diet. Post-surgical analgesic treatment was provided with ibupro- fen 600mg, administered every8hfortwo days after the surgery, and later on if needed. The patientswere instructedto rinsethe mouthwith a 0.2% chlorhexidine mouthwash t.i.d. without brushing the implant area (Figs. 6 & 7). P r o s t h e t i c p r o t o c o l Afterthreetofourmonths ofhealing, a definitive impressionwastakenattheimplantorabutment level according to a previously reported proto- col.27 Definitive prostheses with titanium or zir- conia frameworks, fabricated using CAD/CAM technology (NobelProcera), were screwed on at either the implant or abutment level according to the manufacturer’s instructions three to five monthsafterimplantplacement(inthemandible and the maxilla, respectively). The definitive im- plant-supported complete-arch FDP was de- signed with (hybrid design) or without pink ma- terial in the cervical region (crown design) and veneered with ceramic, acrylic or composite according to the patients’ needs (Figs. 8a–c). Clinical accuracy of the framework (strain-free screwing and absence of an open margin upon clinical and radiographic examination) was eval- uated before prosthesis delivery.28–30 The occlu- sion was adjusted avoiding any premature con- tacts. Mutually protected occlusion with anteriorguidanceorbalancedocclusionwasused in cases of opposing natural dentition or an FDP and complete removable denture, respectively. Follow-up visits were scheduled at one and six months and then annually up to five years of function. The patients underwent a professional cleaning by a dental hygienist every four to six months (Figs. 9a–c). Panoramic and periapical radiographs were obtained annually after defin- itive prosthesis delivery (Fig. 10). The primaryoutcome measureswere asfollows: –An implant was classified as “successful” when the following criteria31 were fulfilled: did not causepainorsuppuration,didnotshowanymo- bility,didnotshowanysignsofradiolucency,and did not show periimplant bone loss of >1.5mm during the first year and then >0.2mm yearly. – An implant was classified as “surviving” when theimplantremainedinthejawandwasstable aftertheprosthesiswasremoved,eventhough all of the success criteria were not fulfilled. Volume 2 | Issue 2/201619

Pages Overview