Simple device for locating the abutment screw position of a cement-retained implant restoration.

aAffiliate Faculty, Department of Restorative Dentistry, University of Washington; Private practice, Bellevue, Wash. bProfessor, Department of Restorative Dentistry, University of Washington. (J Prosthet Dent 2013;109:272-274) 1 Plate and guide rod engage abutment screw head on cast, with plate lowered and oriented to buccal of adjacent teeth. Cement-retained implant restorations have been reported to have several advantages over their screwretained counterparts, especially with respect to esthetics, occlusion, cost, passive fit, and reduced chair time.1,2 However, there are occasions when the cement-retained restoration requires removal, for example, if the abutment screws loosen or if the restoration needs repair.3,4 In this instance, the crown frequently remains cemented to the abutment. The abutment screw must then be accessed through the crown. The challenge here is to locate the screw position with minimal damage to the restoration, abutment, and possibly implant. Several authors have reported techniques to achieve this, which include reviewing a radiograph of the implant position and estimating the long axis position of the screw,5 using photography to record the position of the abutment before the crown is cemented,6,7 marking the screw access site with a porcelain stain during fabrication,8 or fabricating a vacuum-formed guide or template over the definitive restoration.9,10 The problems associated with these techniques are clear. Estimating the implant position in 2 dimensions either with radiographic or photographic records is inaccurate.5-7 Marking the screw access point may be useful in nonesthetic areas but has limitations with an anterior restoration.8 This article describes the procedure for fabricating a custom-made and precision implant-locating device (PILD) to record the access position of the abutment screw. It is simple, rapid, inexpensive, and gives 3-dimensional information for guiding directional screw access.