European Journal of Orthodontics 19(1997) 29-37 9 1997 European Orthodontic So iety Collagen synthesis from human PDL cells following orthodontic tooth movement*

SUMMARY The dynamic remodelling processes in the periodontal ligament (PDL) account for the reaction of PDL cells to different orthodontic force sirnulations. These occur mostly by degradation and synthesis of collagen types I, III, V, VI, XII and XIV. The purpose of this study was to quantify specific collagen types in the PDL from zones of tension and compression of experimental teeth. Such changes could then be correlated with the processes of orthodontic-stimulated tissue breakdown. Maxillary and mandibular premolars of three females and one male patient were orthodontically moved with a box Ioop for a total of 14 days, prior to tooth extraction. Teeth from the contralateral side of either the maxilla or the mandible served as the untreated controls. A total of seven experimental and seven control teeth were used in this investigation. PDL fibroblasts from the cervical third of the roots corresponding to the compression and tension zones of the experimental and control teeth, respectively, were scraped and cultured in vitro at 37 ~ in a humidified incubator with 5 per cent CO2/95 per cent air. Collagen synthesis of types I, III, V and VI was quantified by using an ELISA. Application of orthodontic forces in the experimental teeth showed a significant increas