Clinical performance comparing titanium and titanium–zirconium or zirconia dental implants: a systematic review of randomized controlled trials

Objectives: This study aimed to compare clinical results between titanium (Ti), zirconia (Zr), or titanium–zirconium (TZ) dental implants and to analyze survival rate (SR), bleeding on probing (BoP), marginal bone loss (MBL), and/or probing depth (PD). Data source: Manual and electronic searches were conducted (PubMed and Web of Science) to identify randomized controlled trials that compared the outcomes of at least two implant types (control and test group) within the same study. The focused question was determined according to the PICOT strategy. Seven studies were included out of 202 research studies initially found. The follow-up periods ranged from 12 to 80 months, and the mean age was from 43.3 to 65.8 years old. The SR for Ti, TZ, and Zr implants ranged from 92.6% to 100%, 95.8% to 100%, and 87.5% to 91.25%, respectively; MBL for Ti, TZ, and Zr implants varied from −1.17 mm to −0.125 mm for Ti, −0.6 mm to −0.32 mm for TZ, and −0.25 mm to −1.38 mm for Zr. Studies showed a low incidence of mucositis and peri-implantitis; however, BoP for Zr was 16.43%, Ti ranged between 10% and 20%, and TZ from 10% to 13.8%. PD for Ti ranged from 1.6 mm to 3.05 mm, TZ was 3.12 mm (only one study), and Zr ranged from 2.21 mm to 2.6 mm. Conclusion: All three types of implants showed similar tissue behavior. However, the TZ group had better results when compared with Ti and Zr for SR, MBL, and BoP, except for PD. Furthermore, the worst SR was found in the Zr implants group.