Short implants supporting single crowns in atrophic jaws

Abstract

Data sources: PubMed-Medline, Web of Science, Cochrane Library, ProQuest Dissertations and Theses, LILACS, Ebsco-Dentistry and Oral Sciences Source, Scirus, Embase, Scopus and Journal Ovid databases were searched. In addition hand searching of 14 relevant journals was undertaken along with screening of the reference lists of screened article and reviews.

Study selection: Randomised controlled clinical trials (RCTs), controlled clinical trials (CCTs), prospective cohort studies and case series were included. Studies where short (<10 mm) implants were placed in non-augmented healed alveolar bone with a minimum of ten implants and follow up of one year were considered.

Data extraction and synthesis: One reviewer carried out the quality assessment. Implant level data were analysed. Meta-analyses were conducted and meta-regression analyses were run as fixed-effect models.

Results: Twenty-one articles reporting 16 studies (ten cohorts and six case series) were included. Seven hundred and sixty-two short implants were followed up for up to 120 months in 360 patients (mean follow-up: 44 ± 33.72 months; mean dropout rate: 5.1%). The means failure proportion (FP), biological failure proportion (BFP), prosthetic failure proportion (PFP) and radiographic marginal bone loss (MBL) were 5.9% (95% CI: 3.7-9.2%), 3.8% (95%CI: 1.9-7.4%), 2.8% (95%CI: 1.4-5.7%) and 0.83 mm (95%CI: 0.54-1.12 mm) respectively. Quantitative analysis showed that placement in the mandible (p = 0.0002) and implants with length ≤ 8 mm (p = 0.01) increased FP, BFP and MBL, whereas qualitative assessment revealed that crown-to-implant ratio did not influence MBL.

Conclusions: Within the limitations of the present systematic review with meta-analysis, it is suggested that single crowns supported by short implants are an acceptable and predictable option in the short- and long-term treatment of the atrophic jaws.