Format of Original
Nature Publishing Group (Macmillan Publishers Limited)
PubMed/Medline, Embase and Cochrane Library databases supplemented by searches of the journals; Clinical Implant Dentistry and Related Research, Clinical Oral Implants Research, International Journal of Oral and Maxillofacial Implants, International Journal of Oral and Maxillofacial Surgery, Journal of Clinical Periodontology, Journal of Dentistry, Journal of Oral and Maxillofacial Surgery, Journal of Oral Implantology, Journal of Oral Rehabilitation, Journal of Periodontology, Periodontology 2000.
Randomised controlled trials (RCTs) and prospective studies with at least ten patients, published in the last ten years that compared short and standard implants and published in English were considered.
Data extraction and synthesis
A single author abstracted data with checking by a second reviewer. Methodological quality was assessed using the Jadad Scale and the Cochrane risk of bias tool. Risk ratios (RR) were calculated for implant survival rates, complications and prostheses failures and marginal bone loss was evaluated using mean difference (MD).
Thirteen studies consisting of ten RCTs and three prospective studies were included. The ten RCTs were considered to be of high quality. Two thousand six hundred and thirty-one implants were placed in 1269 patients (981 short and 1650 standard implants). Thirty-eight short implants failed (3.87%) and 45 standard implants (2.72%). Random effects meta-analysis found no statistically significant difference between standard implants and short implants placed in the posterior regions; RR =1.35 (95% CI; 0.82-2.22: P=0.24). Marginal bone loss was evaluated in nine studies and no differences in marginal bone loss were observed. Complications were reported by seven studies and no significant difference was seen between standard and short implants; RR= 0.54 (95% CI; 0.27-1.09: P = 0.08). There was also no significant difference in prosthesis failures between standard and short implants; RR= 0.96 (95% CI: 0.44–2.09: P = 0.92)
Short implants showed marginal bone loss, prosthesis failures and complication rates similar to standard implants, being considered a predictable treatment for posterior jaws, especially in cases that require complementary surgical procedures. However, short implants with length less than 8 mm (4-7 mm) should be used with caution because they present greater risks for implant failures when compared to standard implants.