title: Comparative study of immediately inserted dental implants in sinus lift: 24 months of follow-up.
abstract: OBJECTIVE
  The primary aim of this study is to evaluate the success rate of immediately inserted dental implants in sinus lift and the secondary aim is to assess the reliability of performing simultaneous surgery for sinus lift, grafting and implant placement in situations of very low residual bone heights (<4 mm) in the posterior maxillae.
  
  
  METHODS
  A series of consecutive patients who sought dental implant rehabilitation were included in this study. The sinus lift cases were selected and divided into two groups based on the maxillary alveolar height, ≥4 mm of radiographically measurable bone height (Group 1) and < 4 mm of bone height (Group 2).
  
  
  RESULTS
  A total of 13 implants were installed in Group 1, whereas 8 implants were installed in Group 2. The success rate for dental implants in the sinus lifts reached 95.2% after a period of 24 months of evaluation, at 100% for Group 1 (bone height ≥ 4 mm) and 87.5% for Group 2 (bone height with < 4 mm). Besides the differences between the percentages of success, statistical differences were not reached when the groups were compared (Fisher's exact test, P = 0.38).
  
  
  CONCLUSIONS
  Despite the limitations of this study, including its low number of participants, the results indicate that simultaneous surgery for sinus lifting, grafting and dental implants in posterior maxillae with very low bone heights (<4 mm) can be performed safely, although with lower success rates than found in patients with higher residual bone heights (>4 mm).
authors.affiliation: Department of Dentistry, Dentistry Postgraduate Program, School of Dentistry, Ponta Grossa State University, Paraná, Brazil.
authors.forename: Marcelo Carlos
authors.initials: MC
authors.lastname: Bortoluzzi
authors.affiliation: Department of Dentistry, Dentistry Postgraduate Program, School of Dentistry, Ponta Grossa State University, Paraná, Brazil.
authors.forename: Rafael
authors.initials: R
authors.lastname: Manfro
authors.affiliation: Department of Dentistry, Dentistry Postgraduate Program, School of Dentistry, Ponta Grossa State University, Paraná, Brazil.
authors.forename: Vinícius
authors.initials: V
authors.lastname: Fabris
authors.affiliation: Department of Dentistry, Dentistry Postgraduate Program, School of Dentistry, Ponta Grossa State University, Paraná, Brazil.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Cecconello
authors.affiliation: Department of Dentistry, Dentistry Postgraduate Program, School of Dentistry, Ponta Grossa State University, Paraná, Brazil.
authors.forename: Estevo D'Agostini
authors.initials: ED
authors.lastname: Derech
keywords: Dental implants; immediate dental implants; sinus lift