title: Marginal bone loss around implants placed in maxillary native bone or grafted sinuses: a retrospective cohort study.
abstract: OBJECTIVE
  To assess differences in marginal bone loss around implants placed in maxillary pristine bone and implants placed following maxillary sinus augmentation over a period of 3 years after functional loading.
  
  
  METHODS
  Two cohorts of subjects (Group 1: Subjects who received sinus augmentation with simultaneous implant placement; Group 2: Subjects who underwent conventional implant placement in posterior maxillary pristine bone) were included in this retrospective study. Radiographic marginal bone loss was measured around one implant per patient on digitized panoramic radiographs that were obtained at the time of prosthesis delivery (baseline) and 12, 24, and 36 months later. The influence of age, gender, smoking habits, history of periodontal disease, and type of prosthetic connection (internal or external) on marginal bone loss was analyzed in function of the type of osseous support (previously grafted or pristine).
  
  
  RESULTS
  A total of 105 subjects were included in this study. Cumulative radiographic marginal bone loss ranged from 0 mm to 3.9 mm after 36 months of functional loading. There were statistically significant differences in marginal bone loss between implants placed in grafted and pristine bone at the 12-month assessment, but not in the subsequent progression rate. External prosthetic connection, smoking, and history of periodontitis negatively influenced peri-implant bone maintenance, regardless of the type of osseous substrate.
  
  
  CONCLUSIONS
  Implants placed in sites that received maxillary sinus augmentation exhibited more marginal bone loss than implants placed in pristine bone, although marginal bone loss mainly occurred during the first 12 months after functional loading. Implants with external implant connection were strongly associated with increased marginal bone loss overtime.
authors: Department of Oral Surgery and Implant Dentistry, School of Dentistry, University of Granada, Granada, Spain.|Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, MI, USA.
authors: P
authors: P
authors: Galindo-Moreno
authors: Private practice, Jaén, Spain.
authors: A
authors: A
authors: Fernández-Jiménez
authors: Department of Periodontics, College of Dentistry, University of Iowa, Iowa City, IA, USA.
authors: G
authors: G
authors: Avila-Ortiz
authors: Department of Stomatology, University of Valencia, Valencia, Spain.
authors: F J
authors: FJ
authors: Silvestre
authors: Orthopedic Surgery Unit, San Cecilio Clinical Hospital, Granada, Spain.
authors: P
authors: P
authors: Hernández-Cortés
authors: Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, MI, USA.
authors: H L
authors: HL
authors: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging / Q000209:etiology*; D003758:Dental Implantation, Endosseous / Q000009:adverse effects*; D015921:Dental Implants / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008437:Maxilla / Q000601:surgery*; D008875:Middle Aged; D010518:Periodontitis / Q000150:complications; D011862:Radiography, Panoramic; D012189:Retrospective Studies; D012307:Risk Factors; D059546:Sinus Floor Augmentation; D012907:Smoking / Q000009:adverse effects
chemical_list: D015921:Dental Implants
keywords: alveolar bone loss; bone grafting; bone resorption; dental implants; maxillary sinus