Evidence-Based Dentistry: Short Bränemark Implants-an Analysis of Longitudinal Studies

Objectives: The purpose of this study is to shine some light on the therapeutic decision whether to employ advanced surgery or short implants based on data concerning the use of these implants found in follow-up studies. Material and methods: The MEDLINE database was consulted for follow-up studies published between the years 1980 and 2004. Specific inclusion and exclusion criteria were established. Results: Data concerning the amount of short implants placed and lost, the moment in which the failure occurred and the related risk factors were gathered on 33 studies, being arranged in tables subject to analysis. The first table accounted for the implants placed/lost according to their design, yielding 16,344 fixations with 786 failures (4.8%); the second table added the implants according to the moment that the failure occurred, whether before or after prosthesis insertion; the third table listed all the risk factors related to these fixations. Conclusion: The analysis revealed that among the risk factors, poor bone quality in association to short implants seems to be relevant to failure. The use of implants with 4 mm in diameter seems to minimize failure in these situations. The 3.75 x 7 mm fixture presented the highest failure rate (9.7%) in 1894 implants analyzed. In spite of this rate being twice the average, it is still a clinically acceptable value. Short implants should be considered when planning advanced surgeries, since they present higher morbidity, require extended clinical periods and involve higher costs to the patient.