The advent of regenerative medicine has brought us the opportunity to regenerate, modify and restore human organs function. Stem cells, a key resource in regenerative medicine, are defined as clonogenic, self-renewing, progenitor cells that can generate into one or more specialized cell types. Stem cells have been classified into three main groups: embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs) and adult/postnatal stem cells (ASCs). The present review focused the attention on ASCs, which have been identified in many perioral tissues such as dental pulp, periodontal ligament, follicle, gingival, alveolar bone and papilla. Human dental pulp stem cells (hDPSCs) are ectodermal-derived stem cells, originating from migrating neural crest cells and possess mesenchymal stem cell properties. During last decade, hDPSCs have received extensive attention in the field of tissue engineering and regenerative medicine due to their accessibility and ability to differentiate in several cell phenotypes. In this review, we have carefully described the potential of hDPSCs to differentiate into odontoblasts, osteocytes/osteoblasts, adipocytes, chondrocytes and neural cells.

All of the 28 implants placed in combination with sinus membrane elevation were stable during the first year of loading. No extra costs for biomaterial or morbidity for bone harvesting were necessary.

A 59-year-old man suffering from Paget's disease of bone and periodontal disease was examined in anticipation of bisphosphonate treatment. The previous therapy with clodronate resulted ineffective and markers of bone turnover were markedly elevated. Periodontal disease was correctly approached and treated with an excellent outcome. 5 mg zoledronate iv infusion induced a remarkable reduction of bone markers which persisted on time within the normal range. After zoledronate treatment no signs of osteonecrosis of the jaw (ONJ) were observed. A correct management of periodontal disease is mandatory in pagetic patients on bisphosphonate treatment.

Objective: Osteoporosis is a systemic disorder characterized by generalized decrease in bone mineral density that can eventually result in fragility fracture. Bisphosphonates have been used in the treatment of osteoporosis for many years in order to inhibit bone resorption. Unfortunately, the use of bisphosphonates has been found to be associated with several adverse events in patients where dental pathologies were present. For this reason, an increased attention has been recommended in those patients where bisphosphonates have been assumed and where dental therapies are mandatory. The aim of this article is to focus on the aspects of implant therapy in patients under bisphosphonates treatment and to produce a bibliographic review of dental implants placed in osteoporotic/osteopenic patients under treatment with oral bisphosphonates. Materials and Methods:The literature review was performed on PUBMED, MEDLINE using as search terms: oral bisphosphonates, dental implants, osteoporosis/osteopenia, osteonecrosis of the jaws (ONJ). Conclusions:In conclusion the analysis of the studies shows that the therapy with oral bisphosphonates does not affect osteointegration of dental implants and in most cases determines a low risk of ONJ. Keywords: Oral bisphosphonates; Dental implants; Osteoporosis/ osteopenia; Osteonecrosis of the jaws (ONJ) IntroductionOsteoporosis is a systemic skeletal disorder characterized by skeletal fragility, and macro/micro-architectural modifications [1]. Osteoporosis is one of the most common chronic diseases referred in 1/3 postmenopausal women and 1/5, men over the age of 50 years (European Parliament Osteoporosis Interest Group and EU Osteoporosis Consultation Panel 2004) [2]. For example in Europe, the USA and Japan, osteoporosis is estimated to affect 75 million people [3] ; currently, it is estimated that over 200 million people worldwide suffer from this disease, and the incidence of osteoporosis increases exponentially after the age of 50 [4] . In fact one third of women and one-fifth of men over 50 had experienced osteoporotic fractures [5,6]. The risk of hip, forearm and vertebrae fracture is approximately 40% the same as the risk of cardiovascular disease [6]. According to some authors, 40% of women [7,8] or 50% of women over 50 [9] and up to 29% of men may sustain an osteoporotic fracture. A higher prevalence of fragility fractures has been described in white populations [10], especially in non Hispanic-Caucasians [11]; lower rates have been found among black populations [10]. In Europe, the Scandinavian countries have the highest prevalence of fragility fractures [12]. Although it is widely recognized that low bone mass is not the only determinant of bone fragility, the strength of the skeleton is influenced by other bone tissue properties, collectively named "bone quality" [13,14]. The mean change of bone remodelling pattern in osteoporosis patients resulted in perforation of trabecular plates and loss of cancellous trabecular elements with consequent bone mineral densit...