All-ceramic restoration of zirconia two-piece implants - a randomized controlled clinical trial

ObjectivesAim of this controlled prospective randomized study was to evaluate the outcome of two-piece zirconia implants compared to titanium implants over a period of up to 24months. Material and methodsA total of 31 implants (16 zirconia/Ziterion vario Z((R))+15 titanium/Ziterion vario T-(R)) were inserted primary stable (>30Ncm) in the maxilla (7) and mandible (24) of 22 patients (13 male, nine female) requiring neither bone nor soft tissue augmentation. After a healing period of 6months in the maxilla and 4months in the mandible, ceramic abutments were luted adhesively to the zirconia implants and definitive all-ceramic restoration was performed with high-density ceramics. Radiographic bone levels, condition of the peri-implant mucosa, aesthetic outcome, implant survival and success were recorded for up to 24months. ResultsMeasurements of mean marginal bone levels 24months after surgery showed a significant bone loss (P<0.001) in both groups (Ti: 1.43 (SD0.67) vs. Zir 1.48 (SD +/- 1.05). One zirconia implant was lost 8months after restoration. No further complications were recorded, giving an overall survival and success rate of 93.3% for zirconia and 100% for titanium implants after a period of up to 24months. ConclusionsAfter 24months, success rates of the two-piece ceramic implants showed no significant difference compared to control two-piece titanium implants. The bonded zirconia implant abutment connection appears to be capable with clinical application over the observed period. However, further control measurements need to confirm the presented data.