CAD/CAM international magazine of digital dentistry

_Introduction The advent of CAD/CAM technology and the more widespread utilisation of implants in modern den- tistry have led to an explosion of treatment solutions designed to address any situation encountered by the general dentist. As patients have become more awareofthebenefitsofimplanttherapy,theyhavebe- gun to demand more immediate restoration of their teeth. The provision of a fixed prosthesis has always been the goal in dentistry; however, the cost of such treatment is pricing the vast majority of patients out of the implant market. Immedi- ate loading, avoiding conventional grafting tech- niques by placing implants at various angulations (All-on-4, Nobel Biocare; ColumbusBridge,BIOMET3i),hasresulted inasignificantuptakeoftreatmentbyedentu- louspatientsandthosewithafailingdentition. This is mainly because a fixed bridge is provided and treatment times are reduced from months to hours, avoiding a conventional denture. Mostedentulouspatientscantolerateacomplete maxillary denture with few problems. The vast ma- jority of problems arise in the mandible, where the underlying supporting tissues are not designed to function under this type of occlusal loading. Even a properly constructed complete lower denture can moveasmuchas10mminfunction.Thiscontinuous movement of the prosthesis results in loss of the supporting bone (or remodelling), further destabil- ising the denture. Poor ridge form increases den- ture instability and this produces more remodelling. Edentulism fulfils the WHO definition of a physical impairment. _Treatment protocol A simple treatment protocol was devised to treat this problem. According to this protocol, two dental implantsareplacedintheinter-foraminalareaofthe mandible, to which either a bar or stud attachments areconnectedtoretainthelowerdenture.Thistreat- ment greatly improves both masticatory efficiency and function in patients. Over the last two decades, attempts have been made to render the implant- retained overdenture the standard treatment for edentulism,1 as demonstrated most recently by the McGill consensus.2 Prosthetic failure, usually loss of retention, and the technical difficulties encountered when relining or changing stud attachments proved to be major negative factors in dentists’ attitudes towards this treatment modality. Several attempts were made to redesign and improve the attachments; however, owing to previous negative experiences, most den- tists became reluctant to adopt implant-retained overdenturesasaroutinetreatmentoption.Thepush to place more implants in an attempt to improve the situation led to the bar- and clip-retained over- denture scenario. This technique was more success- ful but still encountered similar issues to the stud- attachment overdentures.3 I research _ SFI-Bar The implant-retained bar overdenture:The SFI-Bar Author_Dr Tussavir Tambra, United Kingdom 14 I Fig. 2a Fig. 1 Fig. 2b Fig. 2c Fig. 3 CAD/CAM 3_2012