CAD/CAM - international magazine of digital dentistry

16 I I opinion _ CBCT _With all the technologies available to dental practitioners today, very few can be described as “career altering”. One of my original reasons for in- vesting in a CBCT scanner was to assist with the complete evaluation of dental implant sites. A major concern during implant placement is the possibility of placing an implant too close to or penetratingtheinferioralveolarnervecanal,likelyre- sulting in injuries such as paraesthesia, anaesthesia or dysaesthesia. In preparation for the insertion of fixtures, I wanted to be able to visualise important anatomic landmarks appropriately, such as the infe- rior alveolar nerve canal, mental foramen, maxillary sinus,incisivecanal,nasalfloor,mylohyoidridge,and the location and morphologic variation of adjacent teeth. The data provided by the scan allows the den- tist to locate such structures accurately beforehand, so that they and potential iatrogenic injuries can be effectively avoided during surgery. Obviously, with traditional 2-D radiographs, Icouldvisualisethegenerallocationoftheseentities and the approximate height of the alveolus, but a 3-D scan provides more information about the mor- phologyofthatridge—itsheightandwidthtowithin a hundredth of a millimetre, as well as its angulation and variation of its form. Currently, I feel that the scope of data garnered from the CBCT scan is im- perative for placing implants safely and correctly for the best restorative options, and this technology has indeed altered my approach to dentistry. I continue tolearnfromeachcasethatIperformbytakinglow- radiation, limited, post-operative scans, which help me become a better surgeon. Theclear,virtual,revolvingmodelofthedentition captured on the CBCT scan can be rotated, zoomed in on from any angle and viewed in 360° to assist in the determination of the implant site, as well as for the fixture’s proper inclination, length and diameter. Asanaddedbenefit,therearenumerousCBCT-com- patible, implant-positioning software programmes available, such as SimPlant (Materialise Dental), NobelGuide (Nobel Biocare), EasyGuide (Keystone Dental) and InVivo5 (Anatomage). Besides its usefulness for implant patients, my CBCT has a myriad of other benefits. I use it to gain information for many of the procedures performed in my practice: extractions; diagnosis and treatment of pathology; orthognathic surgery; airway studies; dental,oralandmaxillo-facialtrauma;bonegrafting; and evaluation of the paranasal sinuses. For example, a CB image can show the relation- ship of a tooth to vital structures such as nerves, the sinus or other teeth, which could turn an apparently simple extraction into a complicated one or provide dentists with information to treat complex extrac- tions more easily. Using preoperative 3-D recon- structions, like those produced by InVivo5, has be- come indispensable preceding my treatment of jaw tumours,congenitalanddevelopmentaldeformities, or maxillo-facial trauma. In addition to educating me regarding preopera- tiveplanning,theCBCTallowspatientstounderstand my reasons for the treatment that has been sug- gestedbetter,sotheyfeelmoreinvolvedintheirown dental health planning decisions. When they must decide between an implant and other possible treat- mentoptions,the3-Dimagesillustrateandenhance CAD/CAM 1_2012 CBCT and implants: Acareer-altering experience Author_ Dr Steven A. Guttenberg, USA Fig. 1