The 15/16 Gracey Curette was introduced in 1993. It is designed for increased access to molars where it can be difficult to position the 11/12 Gracey curette correctly. It is used on the mesial surfaces of the posterior teeth but has the shank design of a Gracey 13/14 (Figures 11‑12).
In the clinical view of this region of the mouth, it is usually necessary to use an extraoral fulcrum to achieve a parallel shank angle with the 11/12 (Figure 13). With the increased angle of the 15/16, a superior adaptation is provided in this area and allows for the choice of an intraoral fulcrum position (Figure 14).
The 17/18 Gracey Curette is designed to improve access to the distal surfaces of posterior teeth (Figure 15). The deep angle of the shank, along with multiple bends, provides crown clearance and prevents interference of the handle with the opposing arch and teeth. It also has a long terminal shank and reduced blade length in order to access deep periodontal pockets on the distal areas. In addition, the shorter blade length allows better access to furcations and root concavities.
When comparing the terminal shank and blade of 13/14 After Five and 17/18 Gracey Curette, the terminal shank is almost as long as an After Five Gracey. This can increase access in periodontal pockets (Figures 16‑17). The blade is 1mm shorter than standard Gracey blades which allows for adaption to more of the tooth surface by the blade (Figures 18‑19).