IM0310

I 31 study _ design and surfaces I implants3_2010 Fig. 4a_Extraction of central incisor and canine. Fig. 4b_Paralleling tools in extraction sits. Fig. 4c_Two 3.75 mm Tapered Self Thread Implant placed in the fresh sockets. Fig. 4d_Abutments placed on im- plants for immediate provisional restoration. _Results There were no dropouts of patients during the follow-upstages.Priortoperformingtheprosthe- sis, the implant site was evaluated to determine osseointegration. Five implants 3.47 % were recorded as failures during the follow-up period. Two of the failed implants, 2.81 %, were in maxilla and three of the implants, 4.10 %, in the mandible. Failed implants were present in five patients. The distribution of the failed implants regarding sex, jaw type, presented in the following table. Two of the failing implants were identified and removed during Surgical Stage II and one was lost during preparation of temporary restoration. Two of the lost implants, posterior maxilla and poste- rior mandible, were 10 mm long. Three of the lost implants (anterior maxilla and anterior mandible, were 13 mm long. One of the failed implants (anterior maxilla) was placed in the site of bone augmentation and associated with a jaw splitting procedure during Stage I surgery, followed up by using a temporary full denture and commented in protocol at the time of implant placement. Failureswererelatedto: One 10 mm implant located in poor bone qual- ity of posterior maxilla in an extraction site. One 10 mmimplantlocatedinposteriormandible.One 13 mm implant located in anterior maxilla was placed in a resorbed narrow ridge (2 mm). One 13 mm implant, placed in the anterior mandible, immediately after the extraction of a contami- nated fractured tooth. No specific pattern regard- ing fixture size could be observed. All types of implants used in the sinus lift proce- durespresenteda100%successrate.FourImplants were lost in immediate extraction sites, in resorbed bone sites, and poor bone quality, all lost implants were threaded non-coated implants, statistical sig- nificance was not substantiated. Using Pearson’s ChiSquaretestastatisticallysignificantassociation was found between the three types (p = 0.04) _Discussion The results of the study present 3.47% failure rate (five implants). This is a most favorable result takingintoconsiderationthatmanyoftheimplants were placed in most unfavorable sites including those with bone defects, unhealed bone extraction sites,sinusliftprocedures,bonegraftingsites,ridge augmentation and implants placed in extremely narrow ridges.4,5,6 Implants lost were correlated to the posterior zone due to poorer bone quality,7 nar- row ridge and other unfavorable conditions. Poste- riormaxillaandmandiblebonestructureislesscon- densed and therefore the ability of firm osseointe- gration of the implant is reduced. Fig. 4cFig. 4a Fig. 4b Fig. 4d Distribution of implant length 8 mm 10 mm 13 mm 16 mm Total HA Smooth Fit 0 0 3 4 17 TPS Smooth Fit 0 12 33 18 63 Self Thread 0 22 42 0 64 Tab. 4