Clinical and radiographic evaluation of implant-supported single-unit crowns with cantilever extension in posterior areas: A retrospective study with a follow-up of at least 10 years

Background Implant-supported restorations with cantilever extension may display high rates of biological and technical complications. Purpose To report the outcomes of single-unit crowns with cantilever extension (SCCs). Materials and methods Patients with SCCs were reevaluated after >= 10 years of loading. Radiographic marginal bone levels (mBLs) at baseline (ie, delivery of SCCs) and follow-up were calculated and compared between implant surfaces adjacent to and distant from the cantilever extension. Implant survival and success rates were calculated. Results Twenty-one patients with 25 SCs supported by 25 implants were reevaluated after a mean of 13.6 +/- 3.8 years (range: 10-19 years). No implants were lost. The mean overall mBLs changed from 0.99 mm +/- 0.95 at baseline to 0.95 mm +/- 0.99 at follow-up (p = 0.853). The mean pocket probing depths changed from 3.39 mm +/- 0.62 at baseline to 3.34 mm +/- 0.54 at follow-up (p = 0.635). Loss of retention occurred 3x in 2 patients (14.3%). At follow-up, peri-implant health was diagnosed in 10 (48%) and peri-implant mucositis in 11 (52%) patients, respectively. Conclusions Within the limitations of the present study, the use of implant-supported SCs with cantilever extension in posterior areas represents a reliable long-term treatment option with a 100% implant survival rate and minimal marginal bone level changes.