Method: One thousand and twenty patients (809 men and 211 women, aged between 19 and 75 years) received a total of 2130 dental implants. The implants installed were divided into: conical (n=615) and cylindrical shape (n=1515), diameter of 4 (n=1385), 4.3 (n=420) and 5mm (n=325) and length of 10 (n=898), 11.5 (n=499) and 13mm (n=733). All surgical and prosthetic procedures were performed by six experienced dentists that followed strict clinical protocols. All subjects were examined by pre-operative computed tomography and the surgery was planned according to a computer-assisted surgical protocol to define the width and length of each implant. A two stage technique was used in the majority of the cases. The healing time was 6 months in the maxilla and 4 months in the mandible. Second-stage surgery was performed to install the healing abutments. The final impressions were taken with pick-up transfers, custom impression trays and polyether. After careful occlusal adjustment, the definitive restorations were placed.
Result: Sixty four implants failed (53 in men patients, 11 in women patients). Of these failed implants, the majority were cylindrical (n=50, 3.3%), with regular platform (n=48, 3.5 %) and 10 mm long (n=34, 3.8%) but there was no significant association between implant failure and implant shape (p=0.26), implant diameter (p=0.21) or length (p=0.16).
Conclusion: The results obtained in this retrospective study revealed that implants had high survival rates and the diameter, length or implant shape did not influence the failure rates.