Conventional drills versus piezosurgery preparation for placement of quadruple immediately loaded zygomatic implants in edentulous patients: a multicenter randomised controlled trial

BACKGROUND: To compare the outcome of preparation of zygomatic implant sites using a conventional preparation with rotary drills or piezosurgery for placing 2 zygomatic implants per zygoma according to a split-mouth design. METHODS: This study was performed at two centres. Each centre recruited 10 patients with atrophic fully edentulous maxilla not having sufficient bone volumes for placing dental implants. The patients had their right side of the mouth randomised to receive either 2 zygomatic implants following conventional site preparation with rotary instruments or piezosurgery. All implants had a diameter of 4.3 mm. Implants were immediately loaded with provisional prostheses which, 6 moths later, were replaced with definitive screw-retained prostheses. Patients were followed to 4 months post-loading and preliminary outcome measures were prosthesis and implant failures, complications, presence or absence of haematoma, time of site preparation. RESULTS: Ten patients were randomly allocated to each centre. One patient dropped out after surgery. Up to 4 months post-loading, 2 implants failed on the drill side while none of the implants failed on the other side (p= 0,317). One complication occurred on the piezo side while two complication occured on the drill side (p= 0,414). There were no statisti cally significant differences in prosthesis failures, implant failures and complications. Post operative haematoma looks larger at the drill side in 13 patients, it looks similar in extension at both side in 7 patients (p= 0,180). Tunnel preparation through piezoelectric inserts was 23.50±2.26 minutes while it was 14.35±1.76 minutes through traditional osteotomic rotary drills (p= 0,000). CONCLUSIONS: Zygomatic implants tunnel preparation with piezoelectric inserts and with drills produces comparable clinical results. Piezoelectric inserts allow for smaller haematoma at surgical sites even if with a longer preparation site.