title: Maxillary sinus augmentation by the crestal core elevation technique.
abstract: BACKGROUND
  The crestal core elevation (CCE) technique is reportedly a less invasive procedure than the lateral window elevation technique. We retrospectively evaluated long-term outcomes of CCE procedures over an 11-year time period.
  
  
  METHODS
  Core preparations were made after extractions of 57 upper molars in 45 patients. Extraction sites were drilled with a calibrated trephine bur to an estimated distance of 1 mm from the sinus membrane. The trephined interradicular bone and underlying sinus membrane were imploded into the sinus. The surgical crater and residual extraction socket were filled with deproteinized bovine bone mineral or freeze-dried bone allograft, stabilized, and protected with an absorbable collagen membrane and fully covered with coronally positioned flaps. Implants were placed 4 months later. Success was defined if ≥9 mm available bone height was available. Where the available bone height varied between 7 and 9 mm, implant placement was complemented using the bone-added osteotome sinus floor elevation technique; those sites were defined as a "partial success."
  
  
  RESULTS
  The CCE technique was successful in 31 (68.9%) out of 45 sites, and partially successful in six (13.3%) out of 45 sites. Eight sites failed (17.8%). Surgical failures were caused by core detachment resulting in large tears of the sinus membrane. Implants placed in successful sites presented a 100% survival rate during the study duration.
  
  
  CONCLUSIONS
  CCE implemented simultaneously with molar extractions provided therapeutic benefits and clinical limitations. The subsequent implant placement using CCE revealed an excellent survival rate in the study population evaluated.
authors: Department of Periodontology, The Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel. daniaron@netvision.net.il
authors: Roni
authors: R
authors: Kolerman
authors: Ofer
authors: O
authors: Moses
authors: Zvi
authors: Z
authors: Artzi
authors: Eytan
authors: E
authors: Barnea
authors: Haim
authors: H
authors: Tal
mesh_terms: D020341:Absorbable Implants; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000540:Alveolar Ridge Augmentation / Q000009:adverse effects / Q000379:methods*; D018786:Bone Substitutes / Q000627:therapeutic use; D016025:Bone Transplantation / Q000379:methods; D003094:Collagen; D015921:Dental Implants; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008437:Maxilla / Q000601:surgery*; D008443:Maxillary Sinus / Q000601:surgery*; D008567:Membranes, Artificial; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures; D008963:Molar / Q000601:surgery; D009092:Mucous Membrane / Q000293:injuries; D010027:Osteotomy / Q000379:methods; D012189:Retrospective Studies; D013524:Surgical Flaps; D016019:Survival Analysis; D014081:Tooth Extraction; D020390:Tooth Socket / Q000601:surgery; D016896:Treatment Outcome
chemical_list: D018786:Bone Substitutes; D015921:Dental Implants; D008567:Membranes, Artificial; D003094:Collagen