title: Dynamics of mucosal dimensions after root coverage with a bioresorbable membrane.
abstract: BACKGROUND
  So far, the clinical effects of the placement of a resorbable membrane for guided tissue regeneration have not been studied in humans in great detail. The dynamics of the resorptive processes, in particular, appear to be rather speculative. In the present longitudinal study, specific alterations of the dimensions of the dentogingival mucosa were explored after surgical root coverage by using a bioresorbable membrane and a coronally-repositioned flap.
  
  
  METHODS
  The study population consisted of 14 patients with a total of 31 predominantly shallow, Miller class I, II or III recessions. The thickness of the masticatory and lining mucosa before and after surgical intervention was measured with an ultrasonic device.
  
  
  RESULTS
  Mean (+/-sd) recession depth and width were 2.85+/-1.29 and 4.46+/-1.14 mm, respectively. After 12 months, 51+/-29% of the recession depth (p<0.001) and 13+/-35% of its width (n.s.) were covered. Root coverage seems to be rather defect-type sensitive with best results obtained at canines with relatively shallow recessions. Mucosal thickness was considerably increased after surgery with a gradual decrease during the following 9 months. Thus, thickness of the marginal tissue rose from 0.82+/-0.27 mm to 1.49+/-0.54 mm 3 months after placement of the membrane (p<0.001). After 12 months, a mean thickness of 1.03+/-0.40 mm was observed (p<0.001). Even more pronounced alterations were noted for the alveolar lining mucosa with a threefold increase of thickness 3 months after surgery and a gradual decrease to about 1 mm after 12 months.
  
  
  CONCLUSIONS
  The present results point to the considerable space making capacity of the bioresorbable membrane which probably allows for the ingrowth of a granulation tissue derived from the underlying structures. The gradual decline in mucosal thickness between months 6 and 9 after surgery may be paralleled by the maturation of the granulation tissue while complete resorption of the membrane had been accomplished.
authors.affiliation: Department of Operative Dentistry and Periodontology, University of Heidelberg, Germany.
authors.forename: H P
authors.initials: HP
authors.lastname: Müller
authors.forename: M
authors.initials: M
authors.lastname: Stahl
authors.forename: T
authors.initials: T
authors.lastname: Eger
mesh_terms: D020341:Absorbable Implants; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001672:Biocompatible Materials; D002951:Citrates; D005260:Female; D005889:Gingival Recession / Q000473:pathology / Q000601:surgery*; D016557:Guided Tissue Regeneration, Periodontal / Q000379:methods*; D006801:Humans; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D008567:Membranes, Artificial; D008875:Middle Aged; D009061:Mouth Mucosa / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D011091:Polyesters; D015203:Reproducibility of Results; D014463:Ultrasonography; D014945:Wound Healing
chemical_list: D001672:Biocompatible Materials; D002951:Citrates; C105021:Guidor; D008567:Membranes, Artificial; D011091:Polyesters