Decompression treatment, which is simple to perform and generally well-accepted by patients, is a reliable method to considerably reduce the volume of mandibular odontogenic cystic lesions before surgical removal. Extended decompression time seems to improve results of the reduction process.

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Three-dimension (3D) scaffolds for bone tissue regeneration were produced combining three different phases: nanometric hydroxyapatite (HA) was synthesized by precipitation method and the crystals nucleation took place directly within collagen fibrils following a biologically inspired mineralization process; polycaprolactone was employed to give the material a 3D structure. The chemico-physical analysis carried out to test the material's properties and composition revealed a high similarity in composition and morphology with biologically mineralized collagen fibrils and a scaffold degradation pattern suitable for physiological processes. The micro- computerized tomography (micro-CT) showed 53.53% porosity and a 97.86% mean interconnected pores. Computer-aided design and computer-aided manufacturing (CAD-CAM) technology was used for molding the scaffold's volume (design/shape) and for guiding the surgical procedure (cutting guides). The custom made scaffolds were implanted in sheep mandible using prototyped surgical guides and customized bone plates. After three months healing, scanning electron microscopy (SEM) analysis of the explanted scaffold revealed a massive cell seeding of the scaffold, with cell infiltration within the scaffold's interconnected pores. The micro-CT of the explanted construct showed a good match between the scaffold and the adjacent host's bone, to shield the implant primary stability. Histology confirmed cell penetration and widely documented neoangiogenesis within the entire scaffold's volume. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 723-734, 2017.

Purpose. This study evaluated the efficacy of a regenerative approach using mesenchymal stem cells (MSCs) and CAD-CAM customized pure and porous hydroxyapatite (HA) scaffolds to replace the temporomandibular joint (TMJ) condyle. Methods. Pure HA scaffolds with a 70% total porosity volume were prototyped using CAD-CAM technology to replace the two temporomandibular condyles (left and right) of the same animal. MSCs were derived from the aspirated iliac crest bone marrow, and platelets were obtained from the venous blood of the sheep. Custom-made surgical guides were created by direct metal laser sintering and were used to export the virtual planning of the bone cut lines into the surgical environment. Sheep were sacrificed 4 months postoperatively. The HA scaffolds were explanted, histological specimens were prepared, and histomorphometric analysis was performed. Results. Analysis of the porosity reduction for apposition of newly formed bone showed a statistically significant difference in bone formation between condyles loaded with MSC and condyles without (P < 0.05). The bone ingrowth (BI) relative values of split-mouth comparison (right versus left side) showed a significant difference between condyles with and without MSCs (P < 0.05). Analysis of the test and control sides in the same animal using a split-mouth study design was performed; the condyle with MSCs showed greater bone formation. Conclusion. The split-mouth design confirmed an increment of bone regeneration into the HA scaffold of up to 797% upon application of MSCs.

Mesenchymal stem cells (MSC) and adipose-derived stem cells (ASC) were recently proposed for bone maxillofacial reconstruction in association with biomaterials. For this application MSC must be ex-vivo expanded in order to obtain, for a given volume of implanted biomaterial, a relevant number of bone forming cells. Previously conducted pre-clinical studies suggested that a concentration of 6 x 10 8 ASC associated with 900 mg of anorganic bovine bone (ABB) could be effective for human maxillary sinus floor elevation. A keystone issue to guarantee the quality and safety of Advanced Therapy Medicinal Products containing expanded MSC and ASC is their chromosome stability in culture: this topic has been widely investigated and conflicting results have been published. Abnormal karyotype of human ex-vivo expanded MSC and ASC was found by some authors, while, at the same time, several other studies showed the MSC and ASC karyotype to be normal. It is therefore important that all the results obtained on MSC andASC karyotype analysis be published. Given this context, the aim of this manuscript, aim of this manuscript is to verify the karyotype stability of ASC in view oftheir applications in clinical trials. ASC obtained from the adipose tissue of 4 donors were expanded over extended culture time. Based on previous ASC expansions we hypothesized to be able to obtain 6 x lOS cells by passage 7. Karyotype analysis 000 metaphases was planned to be investigated at passage 2, 7, and 15 in all the cultures. No abnormalities were found in the karyotype of two donors at all the passages tested, while a translocation was found in 2 metaphases of a donor at passage 7, but not at passage 15, and in the fourth donor in 5 metaphases a trisomy was found at passage 15. Chromosomal abnormalities were detected only after extended ASC expansion. Whether these anomalies can be related to risk for the patient's safety will have to be demonstrated by in-vivo studies.

Background: At the beginning of 2020, a new pathogen named SARS-CoV-2 spread from China to the globe, becoming responsible for a potentially lethal acute respiratory syndrome: COVID-19. Direct contact and airborne contamination are the most frequent infection ways of SARS-CoV-2. During routine dental practice, SARS-CoV-2 transmission can occur through direct contact with mucous membranes, oral fluids, and contaminated instruments or inhalation of aerosol from infected patients. Introduction: Tooth extraction often involves exposure to blood and oral fluids, and the use of a rubber dam could be indicated to minimize direct contact and to decrease the amount of potentially infected droplets around the operatory field. The aim of this clinical case is to show how the use of a rubber dam could help in preventing or minimizing COVID-19 exposure during dental extraction. Materials and Methods: A 32-year-old patient reported severe pain and discomfort to an upper first molar due to a deep carious lesion and vertical tooth fracture. Under local anaesthesia, a rubber dam was placed, isolating the whole upper right sextant, and an atraumatic extraction was performed. Results: All three roots were intact, the bone septum was stable, and no oro-antral communication was present. A gauze swab was placed onto the socket and compressed slightly. After 5 minutes, the socket stopped bleeding, and both clamp and rubber dam, were removed. Conclusion: Within the limits of this single case report, the use rubber dam prior to tooth extraction could be a useful device to decrease aerosol spread and exposure to blood.

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