title: Radiographic evaluation of different techniques for ridge preservation after tooth extraction: a randomized controlled clinical trial.
abstract: OBJECTIVE
  To evaluate the radiographic changes of the alveolar ridge following application of different ridge preservation techniques 6 months after tooth extraction.
  
  
  METHODS
  Four treatment modalities were randomly assigned in 40 patients: β-tricalcium-phosphate-particles with polylactid coating (β-TCP), demineralized bovine bone mineral with 10% collagen covered with a collagen matrix (DBBM-C/CM), DBBM-C covered with an autogenous soft-tissue graft (DBBM-C/PG) and spontaneous healing (control). Cone-beam computed tomography scans were performed after treatment and 6 months later.
  
  
  RESULTS
  After 6 months, the vertical changes ranged between -0.6 mm (-10.2%) for control and a gain of 0.3 mm (5.6%) for DBBM-C/PG on the lingual side, and between -2.0 mm (-20.9%) for β-TCP and a gain of 1.2 mm (8.1%) for DBBM-C/PG on the buccal side. The most accentuated ridge width changes were recorded 1 mm below the crest: -3.3 mm (-43.3%, C), -6.1 mm (-77.5%, β-TCP), -1.2 mm (-17.4%, DBBM-C/CM) and -1.4 mm (-18.1%, DBBM-C/PG). At all three levels, DBBM-C with either CM or PG was not significantly differing (p > 0.05), while most other differences between the groups reached statistical significance (p < 0.05).
  
  
  CONCLUSIONS
  Application of DBBM-C, covered with CM or PG, resulted in less vertical and horizontal changes of the alveolar ridge as compared with controls 6 months after extraction.
authors.affiliation: Clinic of Fixed and Removable Prosthodontics and Dental Material Science, University of Zurich, Zurich, Switzerland. ronald.jung@zzm.uzh.ch
authors.forename: Ronald E
authors.initials: RE
authors.lastname: Jung
authors.forename: Alexander
authors.initials: A
authors.lastname: Philipp
authors.forename: Beat M
authors.initials: BM
authors.lastname: Annen
authors.forename: Luca
authors.initials: L
authors.lastname: Signorelli
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Thoma
authors.forename: Christoph H F
authors.initials: CH
authors.lastname: Hämmerle
authors.forename: Thomas
authors.initials: T
authors.lastname: Attin
authors.forename: Patrick
authors.initials: P
authors.lastname: Schmidlin
mesh_terms: D000328:Adult; D000368:Aged; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging / Q000209:etiology / Q000517:prevention & control*; D000704:Analysis of Variance; D001857:Bone Matrix / Q000637:transplantation*; D018786:Bone Substitutes; D002130:Calcium Phosphates / Q000627:therapeutic use; D020099:Coated Materials, Biocompatible / Q000627:therapeutic use*; D003094:Collagen / Q000627:therapeutic use; D054893:Cone-Beam Computed Tomography; D005260:Female; D006801:Humans; D019344:Lactic Acid; D008297:Male; D008875:Middle Aged; D008903:Minerals; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011446:Prospective Studies; D018709:Statistics, Nonparametric; D014081:Tooth Extraction / Q000009:adverse effects*
chemical_list: C077540:Bio-Oss; D018786:Bone Substitutes; D002130:Calcium Phosphates; D020099:Coated Materials, Biocompatible; D008903:Minerals; C485817:beta-tricalcium phosphate; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; D003094:Collagen