Alexandre Anesi

Bioactive glass/hydroxyapatite composites: mechanical properties and biological evaluation.

Bioactive glass/hydroxyapatite composites for bone tissue repair and regeneration have been produced and discussed. The use of a recently developed glass, namely BG_Ca/Mix, with its low tendency to crystallize, allowed one to sinter the samples at a relatively low temperature thus avoiding several adverse effects usually reported in the literature, such as extensive crystallization of the glassy phase, hydroxyapatite (HA) decomposition and reaction between HA and glass. The mechanical properties of the composites with 80wt.% BG_Ca/Mix and 20wt.% HA are sensibly higher than those of Bioglass® 45S5 reference samples due to the presence of HA (mechanically stronger than the 45S5 glass) and to the thermal behaviour of the BG_Ca/Mix, which is able to favour the sintering process of the composites. Biocompatibility tests, performed with murine fibroblasts BALB/3T3 and osteocites MLO-Y4 throughout a multi-parametrical approach, allow one to look with optimism to the produced composites, since both the samples themselves and their extracts do not induce negative effects in cell viability and do not cause inhibition in cell growth.

Sol-gel derived bioactive glasses with low tendency to crystallize: synthesis, post-sintering bioactivity and possible application for the production of porous scaffolds.

A new sol-gel (SG) method is proposed to produce special bioactive glasses (BG_Ca family) characterized by a low tendency to devitrify. These formulations, derived from 45S5 Bioglass®, are characterized by a high content of CaO (45.6 mol%) and by a partial or complete substitution of sodium oxide with potassium oxide (total amount of alkaline oxides: 4.6 mol%), which increases the crystallization temperature up to 900°C. In this way, it is possible to produce them by SG preserving their amorphous nature, in spite of the calcination at 850°C. The sintering behavior of the obtained SG powders is thoroughly investigated and the properties of the sintered bodies are compared to those of the melt-derived (M) counterparts. Furthermore, the SG glass powders are successfully used to produce scaffolds by means of a modified replication technique based on the combined use of polyurethane sponges and polyethylene particles. Finally, in the view of a potential application for bone tissue engineering, the cytotoxicity of the produced materials is evaluated in vitro.

How to improve retromandibular transmasseteric anteroparotid approach for mandibular condylar fractures: our clinical experience.

Fractures of the mandibular condyle are common and account for 25-35% of all mandibular fractures reported in the literature. Even with the development of a consensus on the preference for open reduction and internal fixation of these fractures, the clinician is still faced with a dilemma concerning the optimal approach to the ramus-condyle unit. Limited access and injury to the facial nerve are the most common problems. The most commonly used extraoral approaches are the submandibular, retromandibular and preauricular methods. In this study, we propose a modified cosmetic preauricular incision with a short end in the neck, to improve the transmasseteric anteroparotid (TMAP) approach previously described by Wilson et al. in 2005. We retrospectively analysed 13 patients treated in our department for mandibular condylar fractures. Post-operative complications, occlusal status, interincisal opening and joint tenderness were evaluated at 3 months after surgery. The wider skin incision described here provides a convenient approach for open reduction and rigid internal fixation, and good results were obtained. The follow-up ranged from 6 to 40 months.

Surgical treatment of unilateral condylar hyperplasia with piezosurgery.

IntroductionUnilateral condylar hyperplasia (UCH) is a disorder of unknown etiology mainly seen in growing patients, which results in facial asymmetry. High condylectomy alone or in association with orthognathic surgery can improve the occlusion and the facial aesthetics. Materials and MethodsBetween 2005 and 2012, a total of 5 patients underwent high condylectomy for UCH using a piezoelectric cutting device. All patients were treated postoperatively with functional rehabilitation. ResultsThe long-term follow-up showed that all patients had a satisfactory temporomandibular joint articular function associated with stable occlusion without any recurrence of further condylar growth. ConclusionsHigh condylectomy in the surgical treatment of unilateral UCH seems to be the procedure of choice in growing patients. The use of a piezoelectric cutting device allows a safe and less invasive high condylectomy.

Synergistic use of local flaps for total lower lip reconstruction.

&NA; The authors have indicated no significant interest with commercial supporters.

Expression of CD133 Correlates with Tumor Stage, Lymph Node Metastasis and Recurrence in Oral Squamous Cell Carcinoma

Objective: CD133 is a pentaspan membrane protein expressed by the so-called cancer stem cells (CSC) in the majority of human cancers. The aim of this study was to analyze CD133 expression levels in specimens of oral cancer and to evaluate its relation with disease evolution. Methods: Expression of the CD133 protein was evaluated by immunostaining in a series of oral squamous cell carcinoma (OSCC) and its relation with traditional prognostic indicators and the clinical outcome of patients was analyzed. Results: CD133 expression was highly variable amongst different samples with a median percentage of positive cells of 5 (range 0 - 80; mean = 11) and CD133 staining was not detectable in tumor cells in 29 (43%) cases. No correlation was observed with age at diagnosis, gender and grading while a significant correlation was observed with tumor stage. Kaplan-Meier curves of disease-free survival displayed a significant separation between the negative and positive groups of patients (p = 0.001 by log-rank test) but CD133 staining did not confirm to be an independent predictor of clinical outcome in a multivariate analyses. Conclusion: Expression of CD133 was detectable in the majority of OSCC samples and correlated significantly with tumor stage and the clinical outcome of patients in terms of disease-free survival. Further studies are warranted on a larger series of cases to elucidate the role of CD133 in the development and progression of OSCC and its suitability as a prognostic biomarker.

Structural and ultrastructural analyses of bone regeneration in rabbit cranial osteotomy: Piezosurgery versus traditional osteotomes

Clinical advantages of piezosurgery have been already proved. However, few investigations have focused on the dynamics of bone healing. The aim of this study was to evaluate, in adult rabbits, bone regeneration after cranial linear osteotomies with two piezoelectrical devices (Piezosurgery® Medical - PM and Piezosurgery® Plus - PP), comparing them with conventional rotary osteotomes (RO). PP was characterized by an output power three times higher than PM. Fifteen days after surgery, histomorphometric analyses showed that the osteotomy gap produced with PM and PP was about half the size of that produced by RO, and in a more advanced stage of recovery. Values of regenerated bone area with respect to the total osteotomy area were about double in PM and PP samples compared with RO ones, while the number of TRAP-positive (tartrate-resistant acid phosphatase positive) osteoclasts per linear surface showed a significant increase, suggesting greater bone remodelling. Under scanning electron microscopy, regenerated bone displayed higher cell density and less mineralized matrix compared with pre-existent bone for all devices used. Nanoindentation tests showed no changes in elastic modulus. In conclusion, PM/PP osteotomies can be considered equivalent to each other, and result in more rapid healing compared with those using RO.

Bisphosphonate-Related Osteonecrosis of the Jaw (BRONJ)

Osteonecrosis of the jaw (ONJ) is a rare condition that has been mainly related to the treatment with i.v. bisphosphonates in patients affected by cancer bone disease. The ethiopathology is still unknown and the frequency is between 0.8 and 12 %. It can appear in edentulous patients, but invasive procedures have been demonstrated to increase the risk of developing this complication. Few cases have been described in the endodontic literature. In the next chapter, we will describe ONJ, will analyze the data from literature, and will report expert opinions and guidelines about the best clinical practice in the endodontic field. Finally, since data in this field are limited, we would like to underline that the best treatment plan for cancer patients receiving bisphosphonates and requiring dental procedures is a multidisciplinary, case-by-case approach.

Microsurgical reconstruction of the mandible in a patient with evans syndrome: a case report and review of the literature.

In this report, we describe the first successful case of microvascular free tissue transfer in a patient with Evans Syndrome (ES), a rare form of idiopathic thrombocytopenic purpura (ITP) and associated autoimmune hemolytic anemia (AIHA). Microvascular surgery in the setting of ES is likely to have higher complication rates because of the increased risk of postoperative bleeding and free flap thrombosis. The case presented here opens up to the feasibility of microvascular reconstruction of patients with coagulation disorders like ES. Every effort should be made to control for hemolytic, thrombocytopenic, and thrombophilic states associated with ES. In the absence of evidence-based treatment guidelines for ES, personalized treatment protocols with high-dose corticosteroids, immunoglobulin, and postoperative anticoagulation regimen are highly recommended.