title: Labial soft tissue volume evaluation of different techniques for ridge preservation after tooth extraction: a randomized controlled clinical trial.
abstract: OBJECTIVE
  To volumetrically evaluate soft tissue changes of different ridge preservation techniques compared to spontaneous healing 6 months after tooth extraction.
  
  
  METHODS
  In each of 40 patients, one single-rooted tooth was extracted and four treatment modalities were randomly assigned to the following groups (n = 10 each): A) ß-tricalcium-phosphate-particles with a polylactid coating (ß-TCP), B) demineralized bovine bone mineral with 10% collagen covered with a collagen matrix (DBBM-C/CM), C) DBBM with 10% collagen covered with an autogenous soft tissue punch graft (DBBM-C/PG), D) spontaneous healing (control). Impressions were obtained before extraction and 6 months later, casts were digitized and volumetric changes at the buccal soft tissues were determined. One-way anova was performed and pair-wise Wilcoxon rank sum test with Bonferroni-Holm method was applied for comparison of differences between two groups.
  
  
  RESULTS
  After 6 months, horizontal contour changes accounted for -1.7 ± 0.7 mm (A), -1.2 ± 0.5 mm (B), -1.2 ± 0.7 mm (C) and -1.8 ± 0.8 mm (D). None of the group comparisons reached statistical significance.
  
  
  CONCLUSIONS
  Six months after tooth extraction all groups revealed a horizontal volume change in the buccal soft tissue contour. Application of DBBM-C/CM or DBBM-C/PG reduced the amount of volume resorption compared to ß-TCP or spontaneous healing without reaching statistically significant difference.
authors.affiliation: Clinic of Fixed and Removable Prosthodontics and Dental Material Science, Center of Dental Medicine, University of Zurich, Zurich, Switzerland.
authors.forename: David
authors.initials: D
authors.lastname: Schneider
authors.forename: Patrick R
authors.initials: PR
authors.lastname: Schmidlin
authors.forename: Alexander
authors.initials: A
authors.lastname: Philipp
authors.forename: Beat M
authors.initials: BM
authors.lastname: Annen
authors.forename: Valerie
authors.initials: V
authors.lastname: Ronay
authors.forename: Christoph H F
authors.initials: CH
authors.lastname: Hämmerle
authors.forename: Thomas
authors.initials: T
authors.lastname: Attin
authors.forename: Ronald E
authors.initials: RE
authors.lastname: Jung
mesh_terms: D000539:Alveolar Process / Q000473:pathology; D000540:Alveolar Ridge Augmentation / Q000379:methods*; D064592:Autografts / Q000637:transplantation; D018786:Bone Substitutes / Q000627:therapeutic use; D002130:Calcium Phosphates / Q000627:therapeutic use; D003094:Collagen / Q000627:therapeutic use; D054893:Cone-Beam Computed Tomography / Q000379:methods; D005500:Follow-Up Studies; D005881:Gingiva / Q000473:pathology* / Q000637:transplantation; D016557:Guided Tissue Regeneration, Periodontal / Q000379:methods; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D008903:Minerals / Q000627:therapeutic use; D003765:Models, Dental; D011091:Polyesters / Q000627:therapeutic use; D014081:Tooth Extraction / Q000379:methods*; D020390:Tooth Socket / Q000473:pathology; D014945:Wound Healing / Q000502:physiology
chemical_list: C077540:Bio-Oss; D018786:Bone Substitutes; D002130:Calcium Phosphates; D008903:Minerals; D011091:Polyesters; C471130:beta-tricalcium phosphate-poly-L-lactide copolymer; D003094:Collagen
keywords: CAD/CAM; RCT; bone regeneration; bone substitute; graft material; human; ridge preservation