title: Periodontal healing may be affected by aging: a histologic study in rats.
abstract: OBJECTIVE
  Although wound healing has been reported to be impaired with aging, very little is known about its effect on periodontal tissues. Therefore, the aim of this study was to evaluate, histologically in rats, the influence of aging on a spontaneous periodontal healing model.
  
  
  METHODS
  Twenty-four male Wistar rats were used and assigned to the following groups: control (n = 12; 2 mo old) and aged (n = 12; 18 mo old). Fenestration defects (4 x 3 x 1 mm) were created bilaterally at the buccal aspect of the distal root of the first mandibular molars, and the mandibulae were retrieved 3 and 6 wk postoperatively. The percentage of bone fill and density of newly formed bone, new cementum formation (NC), and the extension of the remaining defect (ERD) were histometrically obtained.
  
  
  RESULTS
  Intragroup analysis demonstrated that, except for cementum, all histological parameters significantly improved over time (p < 0.05). Intergroup analysis additionally showed that the defects were initially similar in size, and that at 3 wk aging negatively influenced newly formed bone (86.38 +/- 2.99% and 73.06 +/- 3.21%, p < 0.001, for groups control and aged, respectively), BF (75.84 +/- 16.53% and 57.70 +/- 22.28%, p = 0.014) and ERD (0.41 +/- 0.20 mm and 1.17 +/- 0.37 mm, p < 0.001). At 6 wk, aging negatively influenced newly formed bone (88.12 +/- 2.90% and 78.19 +/- 5.35%, p < 0.001, for groups control and aged, respectively) and ERD (0.01 +/- 0.006 mm and 0.34 +/- 0.18 mm, p = 0.003), but not BF (98.15 +/- 2.43% and 87.87 +/- 11.63%, p > 0.05). No new cementum was formed along the root surface in the above groups.
  
  
  CONCLUSIONS
  Within the limits of the present study, data analysis suggests that aging may impair, but not prevent, periodontal healing.
authors.affiliation: Department of Prosthodontics and Periodontics, Division of Periodontics, Faculty of Dentistry, Campinas State University, Piracicaba, São Paulo, Brazil.
authors.forename: B B
authors.initials: BB
authors.lastname: Benatti
authors.forename: J B C
authors.initials: JB
authors.lastname: Neto
authors.forename: M Z
authors.initials: MZ
authors.lastname: Casati
authors.forename: E A
authors.initials: EA
authors.lastname: Sallum
authors.forename: A W
authors.initials: AW
authors.lastname: Sallum
authors.forename: F H
authors.initials: FH
authors.lastname: Nociti
mesh_terms: D000375:Aging / Q000502:physiology*; D000704:Analysis of Variance; D000818:Animals; D001861:Bone Regeneration / Q000502:physiology; D025021:Cementogenesis / Q000502:physiology; D008297:Male; D010519:Periodontium / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D012038:Regeneration / Q000502:physiology*; D018709:Statistics, Nonparametric