title: Transalveolar sinus floor elevation using osteotomes without grafting in severely atrophic maxilla: a 5-year prospective study.
abstract: OBJECTIVE
  The aim of this study was to assess the clinical success of dental implants placed in severely atrophic maxilla (residual bone height ≤4 mm) using transalveolar sinus floor elevation (TSFE) without grafting. Furthermore, the implant stability during the healing period was also evaluated.
  
  
  METHODS
  Twenty five generally healthy patients with 37 Straumann(®) Standard Plus SLA implants were included in the study. After a modified Summers TSFE without grafting was performed, the smooth collar was embedded 0.5-1 mm beneath the cortical bone level. Follow-ups were conducted at 12, 36, and 60 months after crown placement. Implant survival rate, resonance frequency analysis (RFA), and clinical and radiographic parameters were evaluated.
  
  
  RESULTS
  At 5-year follow-up, 35 implants fulfilled the survival criteria, representing a 5-year cumulative survival rate of 94.6% at implant level and 92% at subject level. The mean value of implant stability quotient (ISQ) ranged from 67.8 to 72.8, and the lowest values were reached at 4 weeks. No significant difference was found with the passage of time in modified plaque index (P = 0.92), pocket probing depth (P = 0.34), and modified bleeding index (P = 0.4). The average residual bone height was 2.81 mm (SD: 0.74 mm) in this study. The average crestal bone loss (CBL) significantly increased from 0.83 mm at 1-year examination to 1.47 mm at 3-year examination (P < 0.001). The average CBL remained stable at years 3 and 5 (1.47 vs. 1.54 mm, P = 0.083).
  
  
  CONCLUSIONS
  According to the current evidence, it is feasible to place cylindrical implants in severely atrophic maxilla. High survival rate could be achieved following TSFE without grafting at least within 5-year follow-up.
authors.affiliation: Department of Oral and Maxillo-Facial Implantology, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China.
authors.forename: Ying-Xin
authors.initials: YX
authors.lastname: Gu
authors.affiliation: Department of Oral and Maxillo-Facial Implantology, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China.
authors.forename: Jun-Yu
authors.initials: JY
authors.lastname: Shi
authors.affiliation: Department of Oral and Maxillo-Facial Implantology, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China.
authors.forename: Long-Fei
authors.initials: LF
authors.lastname: Zhuang
authors.affiliation: Department of Oral and Maxillo-Facial Implantology, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China.
authors.forename: Shu-Jiao
authors.initials: SJ
authors.lastname: Qian
authors.affiliation: Department of Oral and Maxillo-Facial Implantology, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China.
authors.forename: Jia-Ji
authors.initials: JJ
authors.lastname: Mo
authors.affiliation: Department of Oral and Maxillo-Facial Implantology, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China.
authors.forename: Hong-Chang
authors.initials: HC
authors.lastname: Lai
mesh_terms: D000328:Adult; D000368:Aged; D001284:Atrophy; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D005260:Female; D006801:Humans; D008297:Male; D008437:Maxilla / Q000473:pathology* / Q000601:surgery*; D008875:Middle Aged; D010027:Osteotomy / Q000295:instrumentation*; D011446:Prospective Studies; D059546:Sinus Floor Augmentation / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D015921:Dental Implants
keywords: dental implants; survival rates; transalveolar sinus floor elevation