title: Histologic evaluation of a stem cell-based sinus-augmentation procedure.
abstract: BACKGROUND
  Predictability has been demonstrated for the long-term success of dental implants placed simultaneously with or after a sinus-augmentation procedure. However, the time required to obtain optimal bone formation can be from 6 to 9 months or longer with grafting materials other than autogenous bone. For this reason, there is interest in a surgical technique that does not require the harvest of autogenous bone but still results in sufficient bone formation within a relatively short time frame.
  
  
  METHODS
  The purpose of this case series was to evaluate the bone formation following sinus-augmentation procedures using an allograft cellular bone matrix containing native mesenchymal stem cells. Biopsy and histologic evaluation were performed after approximately 4 months of healing.
  
  
  RESULTS
  Histomorphometric analysis revealed an average vital bone content of 33% (range, 22% to 40%) and an average residual graft content of 6% (range, 3% to 7%) for the five cases reported that had an average healing period of 4.1 months (range, 3 to 4.75 months).
  
  
  CONCLUSIONS
  The high percentage of vital bone content, after a relatively short healing phase, may encourage a more rapid initiation of implant placement or restoration when a cellular grafting approach is considered.
authors.affiliation: Private practice, Portland, OR, USA.
authors.forename: Bradley S
authors.initials: BS
authors.lastname: McAllister
authors.forename: Kamran
authors.initials: K
authors.lastname: Haghighat
authors.forename: Aron
authors.initials: A
authors.lastname: Gonshor