title: Retracted: Histologic evaluation of new bone in post-extraction sockets induced by melatonin and apigenin: an experimental study in American fox hound dogs.
abstract: The aim of this study was to evaluate the effect of topical applications of melatonin and apigenin (4',5,7-trihydroxyflavone) on new bone formation in post-extraction sockets after 30, 60 and 90 days.
  
  
  
  Six American fox hounds were used in the study, extracting mandibular premolars (P2, P3 and P4) and first molar (M1). Melatonin or apigenin impregnated in collagen sponges were applied at P3, P4 and M1 sites in both hemimandibles; P2 sites were used as control sites. Bone biopsies were taken at 30, 60 and 90 days and stained with hematoxylin-eosin.
  
  
  
  At 30 days, a higher percentage of immature bone was observed in the control group (58.11 ± 1.76%) than in the apigenin (34.11 ± 1.02%) and melatonin groups (24.9 ± 0.14%) with significant differences between the three groups (P < 0.05). At 60 days, results were significantly better at melatonin sites (10.34 ± 1.09%) than apigenin (19.22 ± 0.35%) and control sites (36.7 ± 1.11%) (P < 0.05). At 90 days, immature bone percentages were similar for all groups. New bone formation was higher in melatonin group (79.56 ± 1.9%) than apigenin (68.89 ± 1.5%) and control group (58.87 ± 0.12%).
  
  
  
  Topical applications of either melatonin or apigenin have a potential to accelerate bone tissue in early healing stages; melatonin was seen to have stimulated bone maturation to a greater extent at the 60 days of follow-up.
authors.affiliation: Dentistry, International Dentistry Research Cathedra, Faculty of Medicine and Dentistry, Universidad Católica San Antonio de Murcia (UCAM), Murcia, Spain.
authors.forename: José Luis
authors.initials: JL
authors.lastname: Calvo-Guirado
authors.affiliation: International Dentistry Research Cathedra, Faculty of Medicine and Dentistry, Universidad Católica San Antonio de Murcia (UCAM), Murcia, Spain.
authors.forename: Patricia J
authors.initials: PJ
authors.lastname: López-López
authors.affiliation: Dentistry Department, Universidad San Pablo CEU, Madrid, Spain.
authors.forename: Manuel Fernández
authors.initials: MF
authors.lastname: Domínguez
authors.affiliation: International Dentistry Research Cathedra, Faculty of Medicine and Dentistry, Universidad Católica San Antonio de Murcia (UCAM), Murcia, Spain.
authors.forename: Manuel Maiquez
authors.initials: MM
authors.lastname: Gosálvez
authors.affiliation: Department of Stomatology, Universidad Rey Juan Carlos, Madrid, Spain.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Prados-Frutos
authors.affiliation: Biotecnos, Santa Maria, Brazil.|Catholic University of Uruguay, Montevideo, Uruguay.|Universidad Católica San Antonio de Murcia (UCAM), Murcia, Spain.
authors.forename: Sergio Alexandre
authors.initials: SA
authors.lastname: Gehrke
keywords: apigenin; bone formation; melatonin; socket preservation