Healing of extraction wounds in an experimental model of rat

Introduction: The process of wound healing after tooth extraction has been studied in several animal species under normal and experimental conditions that might interfere with the healing. Chronology of wound healing after tooth extraction (molars and incisors), which consists in several phases, has been examined by histological, radiological, immunohistochemistry, stereology (bone volumetry), and densitometry methods and by using of micro-camera to determine the volume fraction of histological components. The aim of this study is to analyse the process of healing of normal extraction wound and to determine the period of time it takes for the postextraction wound to completely heal. Material and method: The research is based on the literature available in electronic databases Pubmed/Medline, Kobson, Googlescholar. The total of 22 papers which follow the normal course of healing were found; 7 papers met the criteria regarding the complete description of the healing process in the socket after tooth extraction in rats. Results: On the second day after the extraction wound starts with forming epithelium. The first sign of bone tissue has appeared four days after the extraction as subperiostal osteogenesis. On fourth and fifth day, in some fibroblasts differentiation in osteoblasts has already begun. On the fifth day the delicate trabecules of young bone attached to the walls of the socket in its basal part can be seen, and the signs of ossification are clearly indicated by a darker shadow in the central part of the apical third of the socket present in the x ray. The end of the epitelization is on the eighth day, when the lamina dura was slightly less pronounced, while the lower parts of the socket have a pronounced X-ray shadow. In most of the specimens, the socket has been completely filled with reticular bone on day 14. The socket has been filled with young bone after 20 days. Presence of lamelar bone can be seen 60th day after extraction. Remodelation of aveolar ridges lasts until 112th day. Conclusion: The healing of normal extraction wounds in rats begins with the appearance of the epithelium of the second postoperative day, and the end of the epitelization is on the eighth day . Formation of bone begins on the fourth day after the exodontia. The intense bone formation lasts until the twentieth postoperative day when the young r bone fills the socket. Lamellar bone is present on 60th days after extraction. Application of bone morfogenetic protein, low power laser and polarized light had no expected effect on the healing of the extraction wound in experimental rats.