title: Membranes over the lateral window in sinus augmentation procedures: a two-arm and split-mouth randomized clinical trials.
abstract: OBJECTIVE
  This study evaluates whether or not, among other factors, membrane-coverage of antrostomy defects improves implant survival in sinus augmentation procedures.
  
  
  METHODS
  We performed a two-arm and split-mouth randomized controlled clinical trial on 104 and 5 patients respectively. In the two-arm study, antrostomy defects were membrane-covered in 66 procedures and uncovered in 69, before placing a total of 265 implants that were followed up for 1 year. In the split-mouth study, following bilateral sinus augmentation, antrostomy defects were membrane-covered on one side and left uncovered on the contra-lateral. Bone biopsies from each sinus were histologically analysed 6 months later.
  
  
  RESULTS
  In the two-arm study, implant survival rates were similar (p = 0.08) in the membrane-covered (96.1%) and uncovered (94.2%) groups. In the split-mouth study, bone augmentation was similar in both groups (p = 0.52). Delayed implant placement (p = 0.04), thick Schneider's membrane (≥2 mm) (p < 0.01), treatment for hypertension (p = 0.04) and non-smoking (p = 0.01) seemed to be associated with lower risk of implant failure.
  
  
  CONCLUSIONS
  Implant survival in sinus lifting procedures could be influenced significantly by timing of implant placement, Schneider's membrane thickness, antihypertensive treatment and smoking habits, but not by antrostomy membrane coverage.
authors.affiliation: Faculty of Dentistry, Universidad Complutense, Madrid, Spain; Private practice, Clinica Dental Alcalá, Madrid, Spain.
authors.forename: Jesús Torres
authors.initials: JT
authors.lastname: García-Denche
authors.forename: Xixi
authors.initials: X
authors.lastname: Wu
authors.forename: Pedro-Pablo
authors.initials: PP
authors.lastname: Martinez
authors.forename: Hazem
authors.initials: H
authors.lastname: Eimar
authors.forename: Daher Jalil-Abumalham
authors.initials: DJ
authors.lastname: Ikbal
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Hernández
authors.forename: Enrique
authors.initials: E
authors.lastname: López-Cabarcos
authors.forename: Isabel
authors.initials: I
authors.lastname: Fernandez-Tresguerres
authors.forename: Faleh
authors.initials: F
authors.lastname: Tamimi
mesh_terms: D020341:Absorbable Implants; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000959:Antihypertensive Agents / Q000627:therapeutic use; D001706:Biopsy / Q000379:methods; D018786:Bone Substitutes / Q000627:therapeutic use; D003094:Collagen; D003758:Dental Implantation, Endosseous / Q000379:methods; D015921:Dental Implants; D019094:Dental Prosthesis, Implant-Supported; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006973:Hypertension / Q000188:drug therapy; D008297:Male; D008437:Maxilla / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D008443:Maxillary Sinus / Q000473:pathology / Q000601:surgery; D008567:Membranes, Artificial; D008875:Middle Aged; D008903:Minerals / Q000627:therapeutic use; D009297:Nasal Mucosa / Q000473:pathology; D011859:Radiography; D059546:Sinus Floor Augmentation / Q000295:instrumentation / Q000379:methods*; D012907:Smoking; D016019:Survival Analysis; D016896:Treatment Outcome
chemical_list: D000959:Antihypertensive Agents; C106416:Bio-Gide; C077540:Bio-Oss; D018786:Bone Substitutes; D015921:Dental Implants; D008567:Membranes, Artificial; D008903:Minerals; D003094:Collagen
keywords: barrier membranes; bone regeneration; dental implants; risk factors; sinus floor augmentation