Procedural modifications to the ZIP flap technique

In order to address some of the issues highlighted in this early case, the technique was modified slightly to try and prevent flap overgrowth and prosthesis fracture in the early stages. In order to prevent flap overgrowth over the zygomatic oncology implant abutments, the use of a polythene washer was instituted on subsequent cases treated in the unit. Once the flap was perforated, a 2-mm thick polythene sheet (Centriform Soft Mouthguard material, WHW Plastics Ltd., Hull, UK) was taken and a small disc cut out corresponding to an area of 1–2 cm² surrounding the zygomatic oncology implants. Using a 5-mm tissue biopsy punch, holes were cut into the sheet corresponding to the positions of the abutments and the perforated polythene sheet was then placed over the abutments to keep the flap in a superior position during the initial healing phase prior to restoration. The polythene washer was then kept in place using conical abutment protection caps (Fig. 16), and this enabled the prevention of flap tissue overgrowth and retained access to the oncology implants for subsequent restoration (Fig. 17). In view of the fracture of the interim prosthesis reported in this case, the technique was modified with a definitive cobalt chrome framework being constructed within the first 2 weeks post-surgery with one visit for try-in of the framework and tooth set-up being scheduled to allow any modifications required to either incisal level, occlusion and overall soft tissue fit to be completed. This try in visit occurred at 2–3 weeks post-surgery with the final fit occurring 1 week later. This has prevented further issues for all subsequent patients.