Impact of TNF and IL-33 Cytokines on Mast Cells in Neuroinflammation.

Mast cells (MCs) are derived from hematopoietic progenitors, mature in vascularized tissues, and participate in innate and acquired immunity. Neuroinflammation is a highly debated topic in the biomedical literature; however, the impact of tumor necrosis factor (TNF) and IL-33 on MCs in the brain has not been widely addressed. MCs can be activated by IgE binding to FcεRI, as well as by different antigens. After activation, MCs mediate various immunological and inflammatory responses through TNF and IL-33. TNF has two receptors: TNFR1, a p55 molecule, and TNFR2, a p75 molecule. This cytokine is the only one of its kind to be stored in the granules of MCs and can also be generated by de novo synthesis via mRNA. In the central nervous system (CNS), TNF is produced almost exclusively by microglial cells, neurons, astrocytes, and, minimally, by endothelial cells. After its release into brain tissue, TNF rapidly induces the adhesion molecules endothelial leukocyte adhesion molecule 1 (ELAM-1), intercellular adhesion molecule 1 (ICAM-1), and vascular cell adhesion molecule 1 (VCAM-1) in endothelial cells. TNF causes the chemoattraction of neutrophils by inducing several molecules, including CXC chemokines (IL-8). Both MCs and microglial cells act as a primary barrier against foreign molecules in the CNS, producing pro-inflammatory cytokines such as IL-33. IL-33 belongs to the IL-1 family, is activated through the ST2L/IL1-RAcP receptor complex, and mediates both the innate and adaptive immune response. IL-33 is a nuclear transcription factor expressed in the brain, where it induces pro-inflammatory cytokines (TNF and IL-1) and chemokines (CCL2, CCL3, CCL5, and CXCL10). Therefore, MCs and microglia in the CNS are a source of pro-inflammatory cytokines, including TNF and IL-33, that mediate many brain diseases. The inhibition of TNF and IL-33 may represent a new therapeutic approach that could complement existing neuroinflammatory therapies.

Activation of Mast Cells by Neuropeptides: The Role of Pro-Inflammatory and Anti-Inflammatory Cytokines.

Mast cells (MCs) are tissue cells that are derived from bone marrow stem cells that contribute to allergic reactions, inflammatory diseases, innate and adaptive immunity, autoimmunity, and mental disorders. MCs located near the meninges communicate with microglia through the production of mediators such as histamine and tryptase, but also through the secretion of IL-1, IL-6 and TNF, which can create pathological effects in the brain. Preformed chemical mediators of inflammation and tumor necrosis factor (TNF) are rapidly released from the granules of MCs, the only immune cells capable of storing the cytokine TNF, although it can also be produced later through mRNA. The role of MCs in nervous system diseases has been extensively studied and reported in the scientific literature; it is of great clinical interest. However, many of the published articles concern studies on animals (mainly rats or mice) and not on humans. MCs are known to interact with neuropeptides that mediate endothelial cell activation, resulting in central nervous system (CNS) inflammatory disorders. In the brain, MCs interact with neurons causing neuronal excitation with the production of neuropeptides and the release of inflammatory mediators such as cytokines and chemokines. This article explores the current understanding of MC activation by neuropeptide substance P (SP), corticotropin-releasing hormone (CRH), and neurotensin, and the role of pro-inflammatory cytokines, suggesting a therapeutic effect of the anti-inflammatory cytokines IL-37 and IL-38.

Photobiomodulation Enhances the Healing of Postextraction Alveolar Sockets: A Randomized Clinical Trial With Histomorphometric Analysis and Immunohistochemistry.

PURPOSE: Wound healing of postextraction sockets is a complex process that permits to reach the bone reformation in about 3 months, and that could be characterized by the presence of some complications, mainly dependent on the duration of the surgery. The aim of this study is to evaluate the impact of photobiomodulation (PBMT) on the healing processes of mucosa overlying postextraction alveolus and on related complications. METHODS: Twenty systemically healthy patients who needed to extract both lower third molars were selected in a private clinic and included in this prospective split-mouth randomized clinical trial. Inclusion criteria were no smokers subjects with the necessity to extract both lower third molars with surgeries overlapping for duration and difficulty. A computer-based randomization procedure was permitted to choose the side, subject to PBMT, by means of a neodymium-doped YAG (Nd: YAG) laser (test) and controls. Both surgeries were performed by the same operator with a gap of 40 days. Twenty-two days after each surgery, a biopsy in correspondence to the alveolar mucosa of the socket was obtained from both sites and observed with an optical microscope and analyzed with histomorphometric analysis and immunohistochemistry. RESULTS: Each of the 20 participants included in this study (11 women and 9 men, nonsmokers, mean age 16 years in the range of 15 to 17 years) were subjected to the extraction of both lower third molars, and a side was treated as control, the other, as the test. The histomorphometric analysis and immunohistochemistry showed that the tested sites, contrary to controls, were characterized by a lower presence of inflammatory cells, a more mature epithelium and myofibroblasts incorporated in a network of fibers parallel to the basal membrane, with little positivity to alpha-SMA antibodies and anti-myosin but positivity to anti-desmin. CONCLUSIONS: In conclusion, PBMT accelerates the healing process of postextraction alveolus after third molar extraction.

Virtual Articulators and Virtual Mounting Procedures: Where Do We Stand?

A virtual articulator is a computer software tool that is capable of reproducing the relationship between the jaws and simulating jaw movement. It has gradually gained research interest in dentistry over the past decade. In prosthodontics, the virtual articulator should be considered as an additional diagnostic and treatment planning tool to the mechanical articulator, especially in complex cases involving alterations to the vertical dimension of occlusion. Numerous authors have reported on the available digital methodologies used for the assembly of virtual arch models in a virtual articulator, focusing their attention on topics such as the virtual facebow and digital occlusal registration. To correctly simulate jaw movement, the jaw models have to be digitalized and properly mounted on the virtual articulator. The aim of this review was to discuss the current knowledge surrounding the various techniques and methodologies related to virtual mounting in dentistry, and whether virtual articulators will become commonplace in clinical practice in the future. This review also traces the history of the virtual articulator up to its current state and discusses recently developed approaches and workflows for virtual mounting based on current knowledge and technological devices.

Overexpression of ADAR1 into the cytoplasm correlates with a better prognosis of patients with oral squamous cells carcinoma.

BACKGROUND: ADAR1 is an enzymatic protein, which catalyzes a RNA editing reaction by converting Adenosine to Inosine, and its expression has been found to be dysregulated in many cancer types. The aim of this study was to analyze the expression of ADAR1 in oral squamous cells carcinoma. METHODS: In order to analyze the ADAR1 mRNA expression, data from The Cancer Genome Atlas (TCGA) database were downloaded and analyzed. In addition, immunohistochemistry analysis was performed on an institutional database including 46 samples of oral squamous cell carcinoma in a tissue microarray (TMA). RESULTS: No statistically significant correlation linked the mRNA ADAR1 expression to any clinic-pathological variables in the TCGA database. Immunohistochemistry analysis of ADAR1 showed different expressions between normal mucosa and tumor tissue. Focusing on the subcellular localization, the nuclear expression of ADAR1 correlated with higher grading of differentiation (ρ = 0.442; P-value = 0.002); the general expression of ADAR1 either in cytoplasm or in nuclei, correlated with the Gender of patients (Cytoplasm expression: ρ = -0.295; P-value = 0.049; while for nuclear expression: ρ = +0.374; P = 0.011); cytosol expression resulted to be an independent protective prognostic factor (HR = 0.047; C.I. 95% 0.007-0.321; P-value = 0.002). CONCLUSION: Higher expression of ADAR1 into the cytoplasm resulted to be an independent prognostic factor. In order to understand ADAR1 role in cancer, further studies should be performed, in bigger cohort and under a bio-molecular point of view.

Poly D,L-Lactide-Co-Glycolic Acid Grafting Material in Sinus Lift.

The poly D,L-lactide-co-glycolic acid (PLGA) is a copolymer used in many therapeutic devices for its high rates of biodegradability and biocompatibility. The principal aim of the research was to evaluate the new bone formation, after 16 (T1) and 28 weeks (T2), in sheep maxillary sinus lift in vivo model using PLGA.Computerized tomography analysis, X-ray microanalysis, and scanning electron microscope analysis of secondary electrons (SE) and the backscattered electrons (BSE) of the samples were detected.After 28 weeks, the computed tomography analysis showed a 22% increase of UH density in the grafting areas. The X-ray microanalysis of the samples showed calcium and phosphorus increase at T1 and T2 follow-up period and the carbon and oxygen concentration decrease. The SE evaluation showed a rapid superficial resorption of the biomaterials at T1 and a completely bone reorganization of biomaterial at T2. The BSE analysis confirmed the SE data and showed the direct and intimate contact between bone and PLGA with a higher calcification in T2 compared to T1.Certainly, still other experiments and a larger number of samples will be necessary to be analyzed to determine the behavior of the PLGA in the bone regeneration; however, the PLGA used in maxillary sinus lift animal model, seem to promote new bone formation that continues increase at 28 weeks after grafting.

Correlation Between Maxillary Canine Impaction and Facial Biotype.

AIM: The etiology of teeth impaction is still not fully understood, despite that cofactors have been considered important to develop such a clinical picture. The aim of the authors' paper was to investigate about facial biotype, about the values of inclination of the upper cuspid axis to the perpendicular to Frankfort-horizontal plane and about the distance "d" of the canine cuspid to occlusal plane: each factor was statistically compared. The authors also performed a comparative analysis on the radicular length of the left and right lateral incisors of subjects with impacted maxillary canine. METHODS: The authors recruited with "cluster sampling" randomization more than 30 patients, then refined to 25 after the application of exclusion criteria. Specific values were carried out by x-rays: the authors calculated both the α and ß angles, the intermaxillary angle, the distance "d" and the inclination of upper cuspid axis to the perpendicular-to-Frankfort-horizontal plane. Spearman rank correlation coefficient or Spearman rho (ρ) was used as statistical methods. RESULTS: The authors' results assessed that the inclination of the upper cuspid axis to the perpendicular-to-Frankfort-horizontal plane showed a statistically significant inverse correlation with the intermaxillary angle. CONCLUSION: The authors' data clearly indicate that hyperdivergence is a key-factor that will certainly support the eruption path of canine cuspid: in this light, the treatment of tooth impaction in hyperdivergent subjects can be considered as predictive for a good prognosis.

Prosthetic Rehabilitation of Edentulous Patients With Implants Based on Facial Profile Assessment: A Case Report.

PURPOSE: To introduce a user-friendly protocol for implant-retained prosthetic rehabilitation of fully edentulous patients based on facial profile and the cephalometric intermaxillary relationship. MATERIALS AND METHODS: The prosthetic rehabilitation of edentulous patients with implants based on facial profile assessment protocol commences with a clinical and cephalometric analysis, followed by a preliminary projection to obtain a harmonious interarch relationship, eventually stabilized by the preplanned prosthesis. The protocol is divided into the following 5 phases: esthetic evaluation; cephalometric-occlusal assessment; surgery; provisionalization; and definitive prosthesis. Evaluation of patient's satisfaction from the treatment provided was performed through a preoperative and postoperative visual analogue scale scores. RESULTS: The patient was granted immediate function and superior esthetics at day 1 of the treatment. These results were re-evaluated on an interval of 18 months and continued to be stable. The overall treatment time was significantly reduced. CONCLUSION: Our recommended protocol gives the clinician a chance to grasp results beyond the offered by traditional protocols by using a wider perspective of rehabilitation, involving the patient's facial profile, thus fulfilling the integration of both occlusal and cephalometric parameters in a unified surgical-prosthetic approach.

Immunohistochemical Analysis Revealed a Correlation between Musashi-2 and Cyclin-D1 Expression in Patients with Oral Squamous Cells Carcinoma.

AIM: Musashi 2 (MSI2), which is an RNA-binding protein, plays a fundamental role in the oncogenesis of several cancers. The aim of this study is to investigate the expression of MSI2 in Oral Squamous Cell Carcinoma (OSCC) and evaluate its correlation to clinic-pathological variables and prognosis. MATERIALS AND METHODS: A bioinformatic analysis was performed on data downloaded from The Cancer Genome Atlas (TCGA) database. The MSI2 expression data were analysed for their correlation with clinic-pathological and prognostic features. In addition, an immmunohistochemical evaluation of MSI2 expression on 108 OSCC samples included in a tissue microarray and 13 healthy mucosae samples was performed. RESULTS: 241 patients' data from TCGA were included in the final analysis. No DNA mutations were detected for the MSI2 gene, but a hyper methylated condition of the gene emerged. MSI2 mRNA expression correlated with Grading (p = 0.009) and overall survival (p = 0.045), but not with disease free survival (p = 0.549). Males presented a higher MSI2 mRNA expression than females. The immunohistochemical evaluation revealed a weak expression of MSI2 in both OSCC samples and in healthy oral mucosae. In addition, MSI2 expression directly correlated with Cyclin-D1 expression (p = 0.022). However, no correlation has been detected with prognostic outcomes (overall and disease free survival). CONCLUSIONS: The role of MSI2 expression in OSCC seems to be not so closely correlated with prognosis, as in other human neoplasms. The correlation with Cyclin-D1 expression suggests an indirect role that MSI2 might have in the proliferation of OSCC cells, but further studies are needed to confirm such results.

Mast cells participate in allograft rejection: can IL-37 play an inhibitory role?

OBJECTIVE: The aim of this study was to evaluate the role of mast cells (MCs) in allograft rejection, eventually inhibited by IL-37. Immune cells including MCs participate in allograft rejection by generating IL-1, IL-33, TNF and other cytokines. METHODS: We evaluated allograft rejection on the experience of our experimental data and using the relevant literature. RESULTS: MCs are involved in initiation and regulation of innate and adaptive immune responses-pathways. MCs are important pro-inflammatory cells which express high-affinity receptor FceRI and can be activated by IgE and some pro-inflammatory cytokines, such as IL-1 and IL-33. The cross-linkage of high affinity IgE receptor on MCs by antigen ligation has a crucial role in allergy, asthma, anaphylaxis, cancer and allograft rejection. MCs mediate immunity in organ transplant, leading to the activation of allospecific T cells implicated in the rejection and generate pro-inflammatory cytokines/chemokines. IL-1 pro-inflammatory cytokine family members released by MCs mediate allograft rejection and inflammation. IL-37 is also an IL-1 family member generated by macrophage cell line in small amounts, which binds to IL-18Rα and produces an anti-inflammatory effect. IL-37 provokes the inhibition of TLR signaling, TLR-induced mTOR and (MyD88)-mediated responses, suppressing pro-inflammatory IL-1 family members and increasing IL-10. CONCLUSION: IL-37 inhibition offers the opportunity to immunologically modulate MCs, by suppressing their production of IL-1 family members and reducing the risk of allograft rejection, resulting as a potential good therapeutic new cytokine. Here, we report the relationship between inflammatory MCs, allograft rejection and pro-inflammatory and anti-inflammatory IL-37.

Immediate Postextractive Implants With and Without Bone Graft: 3-year Follow-up Results From a Multicenter Controlled Randomized Trial.

PURPOSE: To evaluate the outcome of single postextraction immediate implants placed with and without bone grafts in the esthetic maxillary premolar area for 3-year follow-up after loading. MATERIAL AND METHODS: After tooth extraction, 102 patients received 115 immediate dental implants. Patients were randomly allocated to immediate implant placement with (group A: 51) or without (group B: 51) anorganic bovine bone and resorbable collagen barrier. RESULTS: After 3 years (T36), 1 implant failed in each group. Thirty-seven patients showed inflammation and bleeding, 19 mucositis, and 2 periimplantitis. Statistical significant association was found between BOP and mucositis at T12 (P < 0.0005) and T36 (P < 0.0005). The mesial bone level was -0.61 mm in group B and -1.01 mm in group A (P < 0.001). The group B distal bone level was -0.71 mm and -1.12 mm in group A (P < 0.005). Group B's buccal mean probing was increased (+0.40 mm) than group A (+0.36 mm). Group B's palatal mean value was higher (+0.54 mm) than group A (+0.38 mm). No statistically significant differences were found between the 2 groups. However, the Pink Esthetic Score and patient satisfaction were higher in group B than A (P < 0.001). CONCLUSIONS: The use of anorganic bovine bone substitute with a resorbable collagen barrier in immediate postextractive implants seems to improve the esthetic outcomes after a 3-year follow-up.

Innovative Surgical Management of the Synovial Chondromatosis of Temporo-Mandibular Joints: Highly Conservative Surgical Technique.

Synovial chondromatosis (SC) is an uncommon disease characterized by a benign nodular cartilaginous proliferation arising from the joint synovium, bursae, or tendon sheaths. Although the temporomandibular joint is rarely affected by neoplastic lesions, SC is the most common neoplastic lesion of this joint. The treatment of this disease consists in the extraoral surgery with a wide removal of the lesion; in this study, the authors described a more conservative intraoral surgical approach. Patient with SC of temporomandibular joint typically refer a limitation in the mouth opening, together with a persistent not physiological mandibular protrusion and an appearance of a neoformation located at the right preauricular region: the authors reported 1 scholar patient. After biopsy of the neoformation, confirming the synovial chondromatosis, the patient underwent thus to the surgical excision of the tumor, via authors' conservative transoral approach, to facilitate the enucleation of the neoformation. The mass fully involved the pterygo-maxillary fossa with involvement of the parotid lodge and of the right TMJ: this multifocal extension suggested for a trans-oral surgical procedure, in the light of the suspicion of a possible malignant nature of the neoplasm. Our intraoral conservative approach to surgery is aimed to reduce the presence of unaesthetic scars in preauricular and facial regions, with surgical results undoubtedly comparable to the traditional surgical techniques much more aggressive. Our technique could be a valid, alternative, and safe approach to treat this rare and complex kind of oncological disease.

Innovative Alveolar Ridge Preservation Surgical Technique with Immediate Dental Implant Placement: A Retrospective Case Report of 1-Year Follow-Up.

Following tooth extraction, the alveolar ridge undergoes morphological and dimensional changes, including a clot formation that is gradually replaced by granulation tissue. Studies indicate that both horizontal and vertical ridge dimensions decrease after extraction; however, these changes can be mitigated through grafting with biomaterials and barrier membranes. Alveolar ridge preservation (ARP) techniques are employed to counteract bone resorption postextraction, encompassing periosteal inhibition and modified periosteal inhibition (MPI) techniques. The Degidi clot chamber technique offers a means to achieve biomaterial-free extraction sockets, promoting healing and osteointegration. This study aims to present the first rehabilitation of a postextraction dental implant in the maxilla using an innovative ARP procedure via a MPI technique. The technique does not involve autologous or heterologous grafting materials; instead, a cortical lamina and a customized screw are used in conjunction with the blood clot. The primary objective is to protect the vestibular cortical bone from preosteoclastic aggression, which can trigger bone resorption. The technique employs a 0.5-mm cortical lamina to mechanically shield the vestibular cortical bone, preventing vestibular cortical bone resorption and increasing its thickness without the need for biomaterial insertion, relying on the blood clot. The effectiveness of the technique was assessed through a 12-month postimplantation cone-beam computed tomography scan, revealing a 0.5-mm increase. Although based on a single case, the 1-year follow-up results are promising, and further studies are warranted to validate the technique's efficacy.

Zirconia CAD-CAM Crowns Behavior after Intraoral Digital Impression in Normal versus Dysfunctional Patients: 3 Years Retrospective Study.

OBJECTIVES: The aim of this study was to evaluate the clinical performance and possible complications of single zirconia crowns fabricated using an intraoral digital computer-aided design-computer-aided manufacturing (CAD-CAM) protocol in normal and dysfunctional patients after 3 years of follow-up. MATERIALS AND METHODS: Seventy patients were included in this study. The teeth were prepared with a knife-edge marginal design, and temporary crowns were placed. Digital impressions were taken using optical scanning, and the frameworks were milled using the same technology. The veneering process was performed by the same dental technician. The occlusal corrections were made before cementation. The outcomes were evaluated in terms of survival, failures, and complications. The marginal adaptation of the crowns was also assessed. RESULTS: The digital protocol for single zirconia crowns resulted in satisfactory outcomes, with high rates of survival and minimal complications after 3 years of follow-up. The marginal adaptation of the crowns was excellent, with 93% of the restorations achieving the ideal marginal adaptation, while 7% had minor deviations. Parafunctions were found in 41.9% of the prosthetic rehabilitation, but no significant differences were observed between the normal and dysfunctional groups regarding the survival and complications of the crowns. CONCLUSION: The digital protocol for single zirconia crowns is a reliable and predictable treatment option, even for patients with parafunction, when proper occlusal corrections are performed before cementation. The use of intraoral digital CAD-CAM technologies with optical impressions can simplify procedures, reduce the workflow time, and minimize the variables linked to the human factor.

Comparative Histological Analysis of Dentine-Derived Tooth Grafts in Maxillary vs Mandibular Socket Preservation: A Retrospective Study of 178 Cases.

(1) Background: In recent years, there has been a growing interest in tooth-derived materials as valuable alternatives to synthetic biomaterials for preventing alveolar ridge dimensional changes. This study aimed to evaluate the histological and clinical differences between alveolar ridge preservation procedures in the maxilla and mandible using demineralized dentin treated with Tooth Transformer®. (2) Methods: A total of 178 patients in good general health were enrolled, with 187 post-extractive sockets lacking buccal and/or palatal bone walls. Alveolar socket preservation procedures and histological evaluations were performed. The sites were divided into two groups: Group A (99 mandibular samples) and Group B (108 maxillary samples). After 5 months (±1 month), single bone biopsies were performed for histologic and histomorphometric analysis. (3) Results: Clinical outcomes demonstrated a good healing of hard and soft tissues with an effective maintenance of bone architecture in both groups. Histomorphometric analysis revealed a total bone volume of 50.33% (±14.86) in Group A compared to 43.53% (±12.73) in Group B. The vital new bone volume was 40.59% (±19.90) in Group A versus 29.70% (±17.68) in Group B, with residual graft dentin material volume at 7.95% (±9.85) in Group A compared to 6.75% (±9.62) in Group B. (4) Conclusions: These results indicate that tooth-derived material supports hard tissue reconstruction by following the structure of the surrounding bone tissue. A 6.8% difference observed between the maxilla and mandible reflects the inherent disparities in natural bone structures in these regions. This suggests that the bone regeneration process after tooth extraction adheres to an anatomical functional pattern that reflects the specific bone characteristics of each area, thus contributing to the preservation of the morphology and functionality of the surrounding bone tissue.

IL-37 evaluation in chronic periodontitis after periodontal treatment with and without low level laser therapy.

BACKGROUND: Periodontal disease poses a significant global health challenge. Traditional treatments focus on reducing inflammation and bacterial load, yet novel approaches are continually being investigated. Recent research suggests that IL-37, a potent anti-inflammatory cytokine, may play a crucial role in modulating the inflammatory processes associated with periodontal disease. In conjunction with IL-37, low-level laser therapy (LLLT) has gained attention for its potential in promoting tissue repair, reducing inflammation, and enhancing cellular processes. This study aims to investigate the effects of LLLT on IL-37 in periodontal disease management. METHODS: Thirty patients were enrolled: the G1 group patients were treated with only scaling and root planning-SRP, the G2 group was treated with SRP and LLLT. Before treatment (T0) all periodontal probing pocket depth and bleeding on probing were obtained. Before (T0) and 10 (T1), 30 (T2) and 60 (T3) days after treatment, was achieved plaque sample and specimens of gingival crevicular fluid. Diode laser wavelength range was used between 600-1000 nm and 0.04-60 J/cm2 energy density for 3-s spotlights. RESULTS: In all patients PPD, BOP and IL-37 have shown healing improved parameters. CONCLUSIONS: Although LLLT is widely recommended for its biostimulatory and anti-inflammatory roles, it only showed additional short-term merits in reducing the pocket depth after conventional SRP. Its long-term adjunctive benefits remain unclear. Future RCTs with better study designs, adequate sample power and longer durations of follow-up are required to assess the effectiveness of LLLT as an adjunctive treatment strategy in patients with periodontal disease.

The "Magnificent Seven" in Oral and Systemic Health against COVID-19.

The COVID-19 pandemic impacted all areas of daily life, including medical care. Unfortunately, to date, no specific treatments have been found for the cure of this disease, and therefore, it is advisable to implement all possible strategies to prevent infection. In this context, it is important to better define the role of all behaviors, in particular nutrition, in order to establish whether these can both prevent infection and improve the outcome of the disease in patients with COVID-19. There is sufficient evidence to demonstrate that immune response can be weakened by inadequate nutrition. Nutrition management and treatment are very important to enhance the immune response of an infected person against RNA viral infection. A complete nutritional assessment should include anthropometric, dietary, and laboratorial assessment, as well as a multidisciplinary discussion about the patient's clinical condition. In this way, it is possible to establish an individualized nutritional approach to contribute to improving clinical and nutritional prognoses. From this point of view, diet, through intake of vitamins and trace elements and maintaining adequate functioning of the intestinal barrier, can reduce the severity of the COVID-19 infection. In this study, we provide an overview of the effects of diet on COVID-19 infection in non-cancer patients. This notion needs to be further evaluated, and thus, identification, characterization, and targeting of the right nutrition principles related to the management of patients with COVID-19 are likely to improve outcomes and may prevent the infection or lead to a cure.

A comparison of bovine bone and hydroxyapatite scaffolds during initial bone regeneration: an in vitro evaluation.

OBJECTIVES: To evaluate the different behavior of 3-dimensional biomaterial scaffolds-Bovine Bone (BB; Bio-Oss) and Hydroxyapatite (HA; ENGIpore)-during initial bone healing and development. MATERIALS AND METHODS: Human dental papilla stem cells (hDPaSCs) were selected with FACsorter cytofluorimetric analysis, cultured with osteogenic medium, and analyzed with Alizarin red stained after differentiation. The obtained osteoblast-like cells (OCs) were cultured with BB and HA. alkaline phosphatase (ALP), OC, MEPE, and runt-related transcription factor 2 (RUNX2) expression markers were investigated performing Western blot and reverse transcription-polymerase chain reaction (RT-PCR) analysis. After 40 days, samples were analyzed by light and electron microscopy. RESULTS: All the samples showed high in vitro biocompatibility and qualitative differences of OCs adhesion. RT-PCR and Western blot data exhibited similar marker rate, but ALP, OC, MEPE, and RUNX2expression, during initial healing and bone regeneration phase, was higher and faster in human dental papilla onto BB than in HA scaffolds. In biomaterials growth, RUNX2 seems to play an important role as a key regulator in human OCs from dental papilla bone development. CONCLUSION: Different surface BB scaffold characteristics seem to play a critical role in OCs differentiation showing different time of bone regeneration morphological characteristics as well as higher and faster levels of all observed markers.

New Implant Materials.

In the last forty years, dental implantology has become a widespread worldwide clinical practice in medicine, able to rehabilitate partial or full human edentulism of the jaw and highly successful over the long term [...].

Biologic Bone Behavior During the Osseointegration Process: Histologic, Histomorphometric, and SEM-EDX Evaluations.

This study evaluated bone behavior during dynamic osseointegration. A total of 12 implants were placed in sheep tibia and analyzed at 15, 30, 60, and 90 days. Quantitative and qualitative bone behaviors were evaluated with histologic, histomorphometric, Alizarin Red S, and SEM-EDX (scanning electron microscopy with energy-dispersive x-ray spectroscopy) analysis. Twenty microanalyses were performed in chambers 1, 3, and 5 (a chamber is the distinctive space/bone volume between two coils of the implant screw) in distinctive zones: the titanium-bone interface (zone A), the middle chamber-bone front (zone B), the bone-surgical threading interface (zone C), and native bone (zone D; used as a control). The dynamic osseointegration index (DOI) and bone quality index (BQI) with calcium/phosphorus (Ca/P) content were detected to evaluate the osseointegration quality, bone-to-implant contact (BIC), and bone density around implants. At 15 days, initial bone formation with osteoid matrix deposition and different color intensities were observed (means: BIC = 23.3% ± 3.9%; DOI = 1.55). SEM-EDX analysis showed low mineralized bone/bone marrow with a very low Ca/P mean value. At 30 days, high new bone deposition with higher color intensity in the crestal portion was recorded (BIC = 77.3% ± 0.4%; DOI = 2.58). At 90 days, tight BIC to the middle and apical implant portions were detected, as well as several osteon structures in the crestal portion (BIC = 86.4% ± 0.6%; DOI = 0.96). During all observed time periods, the BQI showed 25% more Ca/P in zone A. Greater maturation degree and lower BQI were seen at zone A compared to the other zones. After 15 and 30 days, zones B and C (except for P in zone B) showed BQIs slightly over 50% and around 75%, respectively, confirming a progressively higher degree of bone maturation that proceeds with the osseointegration process. After 90 days, the BQI values of zones B and C (greater than 70% in zone B and around 90% in zone C) confirmed the bone mineralization and maturation process and an acceleration of implant osseointegration, while a lower BQI value (25%) was recorded in zone A. This study shows osseointegration as a variable dynamic process with a higher bone deposition in contact with the implant surface during the early phase, while in the active and later osseointegration times, the bone quality maturation showed higher values only "at distance" (growth of native bone to the implant surface, observed later in the osseointegration process). After 3 months (before loading), the BQI evaluation was lower (25%) in zone A, confirming that the healing and maturation process of the bone cannot be considered complete.