title: Two-stage crestal sinus elevation by sequential drills in less than 4 mm of residual ridge height: a clinical and histologic case report.
abstract: OBJECTIVE
  The aim of this work, the first human histologic case report of this technique, was a clinical and histologic evaluation of implant placed in a severely atrophic maxilla using a 2-stage crestal sinus elevation.
  
  
  METHODS
  A 52-year-old woman required rehabilitation of an atrophic maxilla with a fixed implant-supported prosthesis. At the first surgery, a crestal sinus lift was performed using beta-tricalcium phosphate (β-TCP), as radiographic tracer, and mineralized human bone allograft (MHBA) as grafting material. After 6 months, a bone core biopsy was taken, and 2 implants were placed in the augmented sites. Four months later, implants were exposed, and 2 splinted gold-porcelain crowns were delivered. Histology highlighted basal bone disappearance, replaced by a wide composite network (∼50% vol/vol) of MHBA granules connected by newly formed bone, and osteoblastic activities.
  
  
  CONCLUSIONS
  This case report demonstrates the possibility of executing a staged transcrestal sinus lift in atrophic situations. MHBA evidenced usefulness in maintaining bone volume. Histologic analyses confirmed the sound outcome of the graft augmentation. Additional studies would be beneficial to confirm or refute the reliability of this technique.
authors.affiliation: *Private Practice, Terranegra, Italy. †Adjunct Professor, Department of Biomedical and Neuromotor Sciences, School of Dentistry, Unit of Periodontology and Implantology, University of Bologna, Bologna, Italy. §Associate Professor of Human Anatomy, Department of Biomedical, Metabolic and Neural Sciences, Human Morphology Section, University of Modena and Reggio Emilia, Modena, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Bernardello
authors.forename: Enrico
authors.initials: E
authors.lastname: Massaron
authors.forename: Sergio
authors.initials: S
authors.lastname: Spinato
authors.forename: Davide
authors.initials: D
authors.lastname: Zaffe
mesh_terms: D000539:Alveolar Process / Q000000981:diagnostic imaging / Q000601:surgery*; D054893:Cone-Beam Computed Tomography; D005260:Female; D006801:Humans; D008875:Middle Aged