Short dental implants (6mm) versus long dental implants (11-15mm) in combination with sinus floor elevation procedures: 3-year results from a multicentre, randomized, controlled clinical trial

AimTo test whether the use of short dental implants (6mm) results in an implant survival rate similar to that with longer implants (11-15mm) in combination with sinus grafting. MethodsThis multicentre study enrolled 101 patients with partial edentulism in the posterior maxilla and a remaining bone height of 5-7mm. Included patients were randomly assigned to receive short implants (6mm; GS/group short) or long implants (11-15mm) simultaneously with sinus grafting (GG/group graft). Six months after implant placement (IP), implants were loaded with single crowns (PR) and patients were re-examined yearly thereafter. Assessed outcomes included: implant survival, marginal bone level changes (MBL), probing pocket depth (PPD), bleeding on probing (BoP) and plaque accumulation (PCR) during 3years of loading as well as recording of any adverse effects. In addition to descriptive statistics, statistical analysis has been performed for the two treatment modalities using a non-parametric approach. ResultsIn 101 patients, 137 implants were placed. At the 3-year follow-up (FU-3), 94 patients with 129 implants were re-examined. The implant survival rate was 100% in both groups. MBL at FU-3 was 0.45mm (GG) and 0.44mm (GS) (p>0.05). A statistically significant loss of MBL was observed in both GG (-0.430.58mm) and GS (-0.44 +/- 0.56mm) from IP to FU-3, and from PR to FU-3 in GG (-0.25 +/- 0.58mm) but not in GS (-0.1 +/- 0.54mm). PCR and BoP at FU-3 did not show any difference between the groups but for PPD (p=0.035). ConclusionsWithin the limitations of this study, implants with a length of 6mm as well as longer implants in combination with a lateral sinus lift may be considered as a treatment option provided a residual ridge height of 5-7mm in the atrophied posterior maxilla is present.