title: Short (6-mm) dental implants versus sinus floor elevation and placement of longer (≥10-mm) dental implants: a randomized controlled trial with a 3-year follow-up.
abstract: OBJECTIVE
  To investigate whether short (6-mm) dental implants could be an alternative to sinus floor elevation (SFE) and placement of longer (≥10-mm) implants in the posterior maxilla.
  
  
  METHODS
  Over a 3-year period, all patients presenting with partial edentulism in the posterior maxilla were considered for inclusion in this randomized controlled trial. Patients were randomly chosen either to receive short (6-mm) implants (test group [TG]) or to undergo SFE with simultaneous placement of standard-length (≥10-mm) implants (control group [CG]). SFE was performed using the lateral technique. In both groups, tapered implants (AnyRidge, MegaGen, Gyeongbuk, South Korea) were placed. All implants were loaded after 4 months of healing. At each annual follow-up session, clinical and radiographic parameters were assessed. Primary outcomes were implant survival, stability (measured with the implant stability quotient [ISQ]), marginal bone loss (MBL), and complications; secondary outcomes were patient satisfaction and treatment time and cost.
  
  
  RESULTS
  Thirty-three patients were assigned to the TG and 20 to the CG. Forty-five implants were inserted in each group. At 3 years, implant survival rates were 100% and 95.0% for the TG and CG, respectively; this difference was not statistically significant (P = 0.38). The mean ISQ values of the TG and CG did not differ at placement (68.2 vs. 67.8, P = 0.1), at delivery of the final restoration (69.5 vs. 69.4, P = 0.9), and after 1 year (71.0 vs. 71.5, P = 0.1); at 3 years, the CG had a significantly higher mean ISQ than the TG (72.4 vs. 71.6, P = 0.004). Mean MBL was significantly higher in the CG than in the TG, both at 1 year (0.14 mm vs. 0.21 mm, P = 0.006) and at 3 years (0.20 mm vs. 0.27 mm, P = 0.01). A few complications were reported. Surgical time and cost were significantly higher in the CG than in the TG (P < 0.0001). Patient satisfaction was high in both groups.
  
  
  CONCLUSIONS
  In this randomized controlled trial, results for short (6-mm) implants were similar to those for longer (≥10-mm) implants in augmented bone. Short implants might be preferable to SFE, because the treatment is faster and less expensive. Long-term randomized controlled trials are required to confirm these results.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Lithuanian University of Health Science, Kaunas, Lithuania.
authors.forename: Souheil
authors.initials: S
authors.lastname: Bechara
authors.affiliation: Department of Oral and Maxillofacial Surgery, Lithuanian University of Health Science, Kaunas, Lithuania.
authors.forename: Ricardas
authors.initials: R
authors.lastname: Kubilius
authors.affiliation: Department of Clinical and Experimental Medicine, University of Varese, Varese, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Veronesi
authors.affiliation: Department of Periodontology and Oral Implantology, Dental Research Division, Guarulhos University, Guarulhos, Sao Paulo, Brazil.
authors.forename: Jefferson T
authors.initials: JT
authors.lastname: Pires
authors.affiliation: Department of Periodontology and Oral Implantology, Dental Research Division, Guarulhos University, Guarulhos, Sao Paulo, Brazil.
authors.forename: Jamil A
authors.initials: JA
authors.lastname: Shibli
authors.affiliation: Department of Surgical and Morphological Sciences, Dental School, University of Varese, Varese, Italy.
authors.forename: Francesco G
authors.initials: FG
authors.lastname: Mangano
mesh_terms: D000328:Adult; D000368:Aged; D003365:Costs and Cost Analysis; D015921:Dental Implants / Q000009:adverse effects / Q000191:economics; D017267:Dental Prosthesis Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000209:etiology; D011446:Prospective Studies; D059546:Sinus Floor Augmentation / Q000009:adverse effects / Q000191:economics; D013997:Time Factors; D055815:Young Adult
chemical_list: D015921:Dental Implants
keywords: complications; marginal bone loss; short implants; sinus floor elevation; stability; survival