Aim . To determine cumulative success rate (CSR) of short and ultrashort implants in the posterior maxilla restored with single crowns. Patients and Methods . We performed a retrospective study in 65 patients with 139 implants. 46 were ultrashort and 93 short. Implants were placed with a staged approach and restored with single crowns. Success rate, clinical and radiographic outcomes, and crown-to-implant ratio (CIR) were assessed after three years. Statistical analysis was performed by descriptive and inferential statistics. A log-binomial regression model where the main outcome was implant success was achieved. Coefficients and 95% confidence intervals were reported. Analyses were performed with Stata 13.2 for Windows. Results . 61.54% of patients were female and mean overall age was <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mn fontstyle="italic">51.9</mml:mn><mml:mo>±</mml:mo><mml:mn fontstyle="italic">11.08</mml:mn></mml:math> years old. Overall CSR was 97.1% (95% CI: 92.4–98.9): 97.9 and 95.1% for short and ultrashort, respectively (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"><mml:mrow><mml:mi>P</mml:mi></mml:mrow></mml:math> value: 0.33). Four implants failed. Covariates were not associated with CSR (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M3"><mml:mrow><mml:mi>P</mml:mi></mml:mrow></mml:math> value > 0.05). Regression model showed coefficients correlated with implant success for ultrashort implants (0.87) and most of covariates but none were statistically significant (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M4"><mml:mrow><mml:mi>P</mml:mi></mml:mrow></mml:math> values > 0.05). Conclusions . Our results suggest that short and ultrashort implants may be successfully placed and restored with single crowns in the resorbed maxillary molar region.
