EDENTULISM PROBLEM: USE OF STEM CELLS FOR BONE REGENERATION AND BONE INFLAMMATION

In this study we have started from a real odontoiatric clinic problem, which affects a high percentage of patients: edentulism. Implant therapy, started by Prof. Branemark in the seventies thanks to the discovery of osseointegration, has developed in the last 15 years. This therapy represents a valid solution for edentulous patients, although it cannot always be used. Severe osseous resorption or anatomical limitations hinder the use of implant and force the employ of biomaterials and/or autologous bone, which, according to the latest scientific research, represents the gold standard. However, intraoral bone graft is not always well tolerated by patients and, in cases of severe atrophy, the quantity of bone that can be taken from the oral cavity is not enough for complete regeneration. Although implant therapy represents the best solution for edentulous patients, in the latest years a biological complication has become more and more frequent: peri-implantitis. It represents a serious problem since it begins with an inflammation of peri-implant hard tissues that clinically leads to a loss of peri-implant alveolar bone and, eventually, to the loss of the implant as a whole. According to the most recent literature, this serious problem affects 10% of the patients and 4% of the implant sites after 10 years of follow-up. To make this pathology even more serious is the little knowledge that clinicians and researchers have about early diagnosis, etiopathogenesis and therapy. The purpose of this study is to address both edentulism and consequent osseous regeneration, as well as the problem of peri-implantitis from a biological point of view and with the help of tissue engineering. In particular, we wanted to test the ability of stem cells taken from adult tissue to favor - in shorter time - osseous regeneration and implant osseointegration both in vitro and on small and large animals. Furthermore, we have tested the anti-inflammatory ability of stem cells in bone tissue. Finally, with regard to the problem of peri-implantitis, we have searched for predictive genetic factors in order to possibly identify patients at risk. Preliminary results of studies performed both in vitro and on animal enable us to state that: -- It is possible to isolate stem cells from different adult tissues (adipose tissue, dental pulp) and test their genetic stability. -- For the cells isolated from dental pulp, we could identify an important connection between patient’s age and ability to differentiate and proliferate. -- Stem cells combined with different scaffolds are able to foster osseous regeneration faster. -- It has been recognized an actual anti-inflammatory ability of stem cells in bone tissue. -- Preliminary results on the use of CGH as genetic predictive technique for peri-implantitis are encouraging since they foreground a correlation between the genetic alteration of some chromosomal tracts and clinical onset of the disease.