Publications by authors named "Silvana Rizzo"

Background: Many studies previously reported epidemiological data on mortality due to COVID-19 among health workers. All these studies included a partial sample of the population with a substantial selection bias. The present study evaluates the trend of mortality among physicians and dentists operating in an area considered to be at high risk during the COVID-19 pandemic.

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The discovery of osseointegration of titanium implants revolutionized the dental prosthesis field. Traditionally, implants have a surface that is processed by additive or subtractive techniques, which have positive effects on the osseointegration process by altering the topography. In the last decade, innovative implant surfaces have been developed, on which biologically active molecules have been immobilized with the aim of increasing stimulation at the implant-biological tissue interface, thus favoring the quality of osseointegration.

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Introduction: Acute Myeloid Leukemia (AML) in pediatric patients is a serious disease, although, for the subgroup of patients who receive proper treatment, a long-term survival rate above 50% is typical. The cycles of chemo- and radiotherapy used to treat AML can impair dental development.

Case Report: Herein, we describe the oral condition of a 25-year-old male patient treated for AML with chemo- and radiotherapy from 5 to 7 years of age; his AML has remained in remission for the past 18 years.

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Background: The aim of this study was to evaluate the ability to identify the contiguity between the root of the mandibular third molar and the mandibular canal (MC) in panoramic radiographs compared with Cone Beam-CT.

Material And Methods: Panoramic radiographs of 326 third molars and CBCT radiographs of 86 cases indicated for surgery and considered at risk were evaluated. The following signs were assessed in panoramic radiographs as risk factors: radiolucent band, loss of MC border, change in MC direction, MC narrowing, root narrowing, root deviation, bifid apex, superimposition, and contact between the root third molar and the MC.

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Background: The onset of perioral wrinkles often prompts patients to request treatment. This aesthetic deterioration linked to aging may be associated with tooth and alveolar bone loss in fully edentulous patients.

Purpose: To evaluate perioral wrinkles before and after maxillary and mandibular rehabilitation with implant-retained dentures in fully edentulous patients.

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Human population is facing a revolutionary change in the demographic structure with an increasing number of elderly people requiring an unmet need to ensure a smooth aging process and dental care is certainly an important aspect that has to be considered. To date, dentistry has been conservative and the need of transferring the scientific models of regenerative dentistry into clinical practice is becoming a necessity. The aim of this study was to characterize the differentiation commitment (in vitro) and the clinical grafting ability (in vivo) of a population of progenitor stem cells obtained after mechanical digestion of dental pulp with an innovative system recently developed.

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Although numerous biomaterials are used for maxillary sinus-lift surgery, the ideal material for such procedures has not yet been identified. Both heterologous and alloplastic bone substitutes have a solely osteoconductive effect and lack the osteoinductive properties of the bone morphogenetic proteins typical of autologous bone. Our group assessed a new alloplastic graft material, poly(lactic-co-glycolic) acid/hydroxyapatite (PLGA/HA), implanted in a human model of maxillary sinus-lift surgery.

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Purpose: Bacterial adhesion and colonization play a crucial function in the pathogenesis of peri-implant tissue infection, which is considered the main cause of fixture loss. The aim of this study is to evaluate the differences in bacterial adhesion between a machined titanium surface, a double acid etched surface (Osseotite®) and an Osseotite surface with Nanometer-scale Discrete Crystalline Deposition (DCD™) of calcium phosphate (CaP)(Nanotite®).

Methods: Surface roughness properties of each sample were determined by a laser profilometer and scanning electron microscopy (SEM) observation.

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An osteoma is a slow-growing, benign lesion comprising mature bone tissue. Osteomas rarely occur in maxillary bones, with the exception of the maxillary sinuses. Various possible etiologies have been proposed, including congenital anomalies, chronic inflammation, muscular activity, embryogenetic changes, and trauma.

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Transformation of primary B lymphocytes by Epstein-Barr virus requires the establishment of a strictly latent infection, the expression of several latent viral proteins, and sustained telomerase activity. Our previous findings indicated that induction of hTERT, the rate-limiting catalytic unit of the telomerase complex, was associated with the expression of the viral latent membrane protein 1 (LMP1). In the present study, we demonstrate that ectopic expression of LMP1 in BJAB and Ramos B cells resulted in an increase of hTERT transcripts, thus suggesting that LMP1 acts at the transcriptional level.

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Functional characterization of signaling pathways that critically control mantle cell lymphoma (MCL) cell growth and survival is relevant to designing new therapies for this lymphoma. We herein demonstrate that the constitutive activation of Akt correlates with the expression of the phosphorylated, inactive form of PTEN. Phosphatidyl-inositol-3 kinase (PI3-K)/Akt or mammalian target of rapamycin (mTOR) inhibition decreased the growth of both primary MCL cultures and established cell lines and antagonizes the growth-promoting activity of CD40 triggering and IL-4.

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Retinoic acid (RA) arrests the growth of EBV-immortalized lymphoblastoid B cell lines (LCLs) by upregulating the cyclin-dependent kinase inhibitor p27Kip1. Here, we show that in LCLs, RA inhibits ubiquitination and proteasome-dependent degradation of p27Kip1, a phenomenon that is associated with downregulation of Thr187 phosphorylation of the protein, whereas the phosphorylation on Ser10 is unaffected. Furthermore, we demonstrate that RA downregulates the expression of the p45Skp2 and Cks1 proteins, two essential components of the SCF(Skp2) ubiquitin ligase complex that target p27Kip1 for degradation.

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Mantle cell lymphoma (MCL) is an aggressive B-cell non-Hodgkin's lymphoma with poor response to therapy and unfavorable prognosis. Here, we show that retinoic acid (RA) isomers significantly inhibit the proliferation of both primary MCL cultures (n = 7) and established cell lines (Granta 519 and SP-53) as shown by [(3)H]thymidine uptake and carboxyfluorescein diacetate succinimidyl ester labeling coupled with cyclin D1 staining. RA induces cell accumulation in G(0)-G(1) together with a marked up-regulation of p27(Kip1) by inhibiting ubiquitination and proteasome-dependent degradation of the protein.

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IL-6-mediated B-cell growth promotion is involved in the pathogenesis of EBV+ lymphoproliferative disorders of immunosuppressed patients. Since retinoic acid (RA) inhibits the proliferation of EBV-immortalized lymphoblastoid B-cell lines (LCLs), we have investigated the effects of RA on IL-6 signaling in these cells. RA down-regulated IL-6-receptor components with IL-6 agonist activity (membrane and soluble gp80) and increased the levels of soluble gp130, an IL-6 antagonist.

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Background: Mouthrinses are widely utilized in daily oral and dental hygiene to control plaque. However, most commercially available mouthrinses contain alcohol as an excipient. Most studies have focused on the clinical side effects related to the alcoholic fraction of mouthrinses, overlooking alcohol metabolism in the mouth.

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In the search for retinoids active against Burkitt's lymphoma (BL), we found that the arotinoid mofarotene (Ro 40-8757) induced strong antiproliferative and apoptotic responses in most established BL cell lines as well as in primary BL cells. Ro 40-8757-induced apoptosis is associated with mitochondrial membrane depolarization, activation of caspase-3 and -9, and enhanced production of reactive oxygen species. These effects were related to a transient drop in intracellular ATP content, probably favored by a downregulation of NADH dehydrogenase subunit-1, a component of the mitochondrial respiratory chain (MRC) Complex I.

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Fourteen titanium dental implants (Tioblast) were implanted singly in the proximal tibia of New Zealand rabbits for 120 days. A bone defect was surgically produced and filled with Bio-Oss around six of these implants. After the animals were sacrificed and their organs harvested, bone segments were fixed and methacrylate embedded after the push-in test had been performed.

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The mechanical stability of the fixture in bone is one of the most important factors for the long-term reliability of dental implants. This paper focuses on an experimental procedure to evaluate the mechanical properties of the bone surrounding dental implants. The procedure is based on a surgical animal model followed by mechanical tests.

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