Capsaicin modulates TRPV1, induces β-defensin expression, and regulates NF-κB in oral senescent cells and a murine model

Aging is associated with a decline in oral immune function, marked by reduced levels of antimicrobial peptides such as defensins. Capsaicin, a bioactive component found in chili peppers, has been theorized to modulate immune responses through specific receptor pathways. This study examined the effects of aging on oral defensin levels and the potential mitigating role of capsaicin, mediated by the immune response in oral tissues. We conducted a comparative analysis between young and aged mice, with or without capsaicin supplementation, for 3 months. The effect of capsaicin was also studied in vitro in senescence-induced human oral keratinocytes. We found that aging did not reduce defensin levels uniformly but did so in some instances. Capsaicin treatment increased defensin levels in these cases, potentially through transient receptor potential cation channel subfamily V member 1 (TRPV1)-mediated pathways in the oral cavity. Capsaicin supplementation may counteract age-related declines in oral defensin levels, enabling the maintenance of oral immune function during aging.

Micro-arc driven porous ZrO2 coating for tailoring surface properties of titanium for dental implants application

Titanium (Ti) is an ideal material for dental implants due to its excellent properties. However, corrosion and mechanical wear lead to Ti ions and particles release, triggering inflammatory responses and bone resorption. To overcome these challenges, surface modification techniques are used, including micro-arc oxidation (MAO). MAO creates adherent, porous coatings on Ti implants with diverse chemical compositions. In this context, zirconia element stands out in its wear and corrosion properties associated with low friction and chemical stability. Therefore, we investigated the impact of adding zirconium oxide (ZrO2) to Ti surfaces through MAO, aiming for improved electrochemical and mechanical properties. Additionally, the antimicrobial and modulatory potentials, cytocompatibility, and proteomic profile of surfaces were investigated. Ti discs were divided into four groups: machined - control (cpTi), treated by MAO with 0.04 M KOH - control (KOH), and two experimental groups incorporating ZrO2 at concentrations of 0.04 M and 0.08 M, composing the KOH@Zr4 and KOH@Zr8 groups. KOH@Zr8 showed higher surface porosity and roughness, even distribution of zirconia, formation of crystalline phases like ZrTiO4, and hydrophilicity. ZrO2 groups showed better mechanical performance including higher hardness values, lower wear area and mass loss, and higher friction coefficient under tribological conditions. The formation of a more compact oxide layer was observed, which favors the electrochemical stability of ZrO2 surfaces. Besides not inducing greater biofilm formation, ZrO2 surfaces reduced the load of pathogenic bacteria evidenced by the DNA-DNA checkerboard analysis. ZrO2 surfaces were cytocompatible with pre-osteoblastic cells. The saliva proteomic profile, evaluated by liquid chromatography coupled with tandem mass spectrometry, was slightly changed by zirconia, with more proteins adsorbed. KOH@Zr8 group notably absorbed proteins crucial for implant biological responses, like albumin and fibronectin. Incorporating ZrO2 improved the mechanical and electrochemical behavior of Ti surfaces, as well as modulated biofilm composition and provided suitable biological responses.

Multilocus sequence typing and phenotypic properties of Streptococcus mutans from Thai children with different caries statuses

BACKGROUND

Streptococcus mutans is studied for its acidogenic and aciduric characteristics, notably its biofilm formation in the presence of sucrose, toward its role in the caries process. Variations in both genotype and phenotype have been reported among clinical isolates of S. mutans. This study aimed to examine genotypic and phenotypic characteristics of S. mutans obtained from Thai children with varying caries statuses.

METHODS

We determined the presence of S. mutans and caries status in 395 children aged 3-4 years. From 325 children carrying S. mutans, we selected 90 with different caries statuses-caries-free (CF; n = 30), low severity of caries (LC; n = 30), or high severity of caries (HC; n = 30). Three isolates of S. mutans were taken from each child, thus, a total of 270 isolates were obtained. Multilocus sequence typing (MLST) was used to genotype the isolates and assess their clonal relationships. The properties, including biofilm formation, collagen binding, and acid production and tolerance were also evaluated.

RESULTS

Children with carious lesions showed a higher detection rate and number of S. mutans in saliva than those without caries. S. mutans from individuals with HC status showed the lowest biofilm formation ability, while this group had the highest detection rate of collagen-binding isolates. There was no difference in acid production or tolerance by caries status. Genotyping by MLST did not reveal any clone of S. mutans specific to CF status. This result remained even when we included MLST data from the open-access PubMLST database. MLST did identify clones containing only strains from caries-affected hosts, but tests of their phenotypic properties did not reveal any differences between S. mutans from these clones and clones that were from both caries-free and caries-affected children.

CONCLUSIONS

The clonal relationships of S. mutans indicated by MLST were not associated with the status of dental caries in the host.

Nitric oxide releasing coatings for the prevention of viral and bacterial infections

Healthcare associated infections (HCAI) represent a significant burden worldwide contributing to morbidity and mortality and result in substantial economic consequences equating to billions annually. Although the impacts of HCAI have been felt for many years, the coronavirus pandemic has had a profound effect, escalating rates of HCAI, even with extensive preventative measures such as vaccination, personal protective equipment, and deep cleaning regimes. Therefore, there is an urgent need for new solutions to mitigate this serious health emergency. In this paper, the fabrication of nitric oxide (NO) releasing dual action polymer coatings for use in healthcare applications is described. The coatings are doped with the NO donor S-nitroso-N-acetylpenicillamine (SNAP) and release high payloads of NO in a sustained manner for in excess of 50 hours. These coatings are extensively characterized in multiple biologically relevant solutions and the antibacterial/antiviral efficacy is studied. For the first time, we assess antibacterial activity in a time course study (1, 2, 4 and 24 h) in both nutrient rich and nutrient poor conditions. Coatings exhibit excellent activity against Pseudomonas aeruginosa and methicillin resistant Staphylococcus aureus (MRSA), with up to complete reduction observed over 24 hours. Additionally, when tested against SARS-CoV-2, the coatings significantly reduced active virus in as little as 10 minutes. These promising results suggest that these coatings could be a valuable addition to existing preventative measures in the fight against HCAIs.

Unveiling the Intricate Link Between Anaerobe Niche and Alzheimer Disease Pathogenesis

Dysbiosis within microbiomes has been increasingly implicated in many systemic illnesses, such as cardiovascular disease, metabolic syndrome, respiratory infections, and Alzheimer disease (Ad). The correlation between Ad and microbial dysbiosis has been repeatedly shown, yet the etiologic cause of microbial dysbiosis remains elusive. From a neuropathology perspective, abnormal (often age-related) changes in the brain, associated structures, and bodily lumens tend toward an accumulation of oxygen-depleted pathologic structures, which are anaerobically selective niches. These anaerobic environments may promote progressive change in the microbial community proximal to the brain and thus deserve further investigation. In this review, we identify and explore what is known about the anaerobic niche near or associated with the brain and the anaerobes that it is harbors. We identify the anaerobe stakeholders within microbiome communities and the impacts on the neurodegenerative processes associated with Ad. Chronic oral dysbiosis in anaerobic dental pockets and the composition of the gut microbiota from fecal stool are the 2 largest anaerobic niche sources of bacterial transference to the brain. At the blood-brain barrier, cerebral atherosclerotic plaques are predominated by anaerobic species intimately associated with the brain vasculature. Focal cerebritis/brain abscess and corpora amylacea may also establish chronic anaerobic niches in direct proximity to brain parenchyma. In exploring the anaerobic niche proximal to the brain, we identify research opportunities to explore potential sources of microbial dysbiosis associated with Ad.

Porous Gelatin Methacrylate Gel Engineered by Freeze-Ultraviolet Promotes Osteogenesis and Angiogenesis

Alveolar bone defect reconstruction is a common challenge in stomatology. To address this, a thermosensitive/photosensitive gelatin methacrylate (GelMA) gel was developed based on various air solubilities and light-curing technologies. The gel was synthesized by using a freeze-ultraviolet (FUV) method to form a porous and quickly (within 15 min) solidifying modified network structure. Unlike other gel scaffolds limited by complex preparation procedures and residual products, this FUV-GelMA gel shows favorable manufacturing ability, promising biocompatibility, and adjustable macroporous structures. The results from a rat model suggested that this gel scaffold creates a conducive microenvironment for mandible reconstruction and vascularization. In vitro experiments further confirmed that the FUV-GelMA gel promotes osteogenic differentiation of human bone marrow mesenchymal stem cells and angiogenesis of human umbilical vein endothelial cells. Investigation of the underlying mechanism focused on the p38 mitogen-activated protein kinase (MAPK) pathway. We found that SB203580, a specific inhibitor of p38 MAPK, abolished the therapeutic effects of the FUV-GelMA gel on osteogenesis and angiogenesis, both in vitro and in vivo. These findings introduced a novel approach for scaffold-based tissue regeneration in future clinical applications.

Tooth Loss in Periodontitis Patients-A Risk Factor for Mild Cognitive Impairment: A Systematic Review and Meta-Analysis

BACKGROUND

Periodontal disease and tooth loss have been long suggested as risk factors of mild cognitive impairment. The underlying mechanisms could be systemic chronic inflammatory mediators, direct pathologic challenge to the nervous system, malnutrition and/or loss of neurosensory stimulation input causing brain atrophy. This review aimed to examine the existing literature studies linking the effect of periodontal disease and tooth loss on the development of mild cognitive impairment.

METHODS

A systematic review using PEO was conducted. Three electronic databases, namely Embase, Medline and DOSS (UCLan), were searched for relevant articles published up to April 2023. Google Scholar and a hand search were also conducted to ensure no relevant studies had been missed. The Newcastle-Ottawa scale was used to assess the quality of studies.

RESULTS

The findings showed that chronic periodontitis and tooth loss, both individually and in combination, led to an increased risk of mild cognitive decline in adults over 50 years. Within the limitations of this review, periodontitis and tooth loss both contribute to an increased risk of mild cognitive impairment and dementia, but the evidence so far is not strong.

CONCLUSIONS

In future, more robustly designed studies investigating periodontal disease and tooth losslink with cognitive health decline are required with a longer follow-up duration.

Medication-Related Osteonecrosis of the Jaw: A Systematic Review of Case Reports and Case Series

Medication-related osteonecrosis of the jaw (MRONJ) is a rare condition, typically seen in patients receiving antiresorptive or antiangiogenic drugs. This study aims to synthesize reports and case series of MRONJ regarding sociodemographic and clinical characteristics and to evaluate the effectiveness of the treatments applied. Following PRISMA guidelines, a search for case reports and case series was carried out in the PubMed-Medline database until March 2024. A total of 88 articles were included in this review, in a total of 151 cases. The key findings reveal that females were the most affected individuals (71% of the cases) with the average age at diagnosis being 66.27 years with a standard deviation of ±13.03. Stage 2 was the most observed stage, in 43% of cases, and zoledronic acid was the most commonly used drug (32% of cases). The oral route was the most common route of administration, in 26% of cases, with an average administration duration of 60.88 months (standard deviation ± 50.92). The mandible was the most commonly affected anatomical location (in 60% of cases). Amoxicillin + clavulanic acid (875 mg + 125 mg) and chlorhexidine (0.12%) were the most used antibiotics and mouthwash, with 16% and 26% of the cases, respectively. Surgical debridement was the most common surgical procedure, in 32% of cases, while the use of an L-PRF membrane was the most prevalent unconventional treatment, in 21% of cases. This study identified a statistically significant relationship between unconventional treatments and the cure of MRONJ (p < 0.001), indicating the need for further research to confirm these results.

Heat-killed Lancefieldella Rimae Induces Bone Resorption by Promoting Osteoclast Differentiation

INTRODUCTION

Apical periodontitis, mainly caused by bacterial infection in the dental pulp, is often accompanied by abscess, periapical inflammation, and alveolar bone loss. Lancefieldella rimae has been detected in the root canals of patients with apical periodontitis. Here, we investigated whether L. rimae is associated with bone resorption.

METHODS

L. rimae was anaerobically cultured and heat-killed (HKLr). A mouse calvarial implantation model was used to determine the bone resorption in vivo. Committed osteoclasts prepared from C57BL/6 wild-type or Toll-like receptor 2 (TLR2)-deficient mice were differentiated into mature osteoclasts in the presence or absence of HKLr. The mRNA expression of tartrate-resistant acid phosphatase (TRAP), ATPase H+ transporting V0 subunit D2, cathepsin K, interleukin-6, tumor necrosis factor-α, and glyceraldehyde 3-phosphate dehydrogenase was quantified using real-time reverse transcription-polymerase chain reaction. The protein levels of c-Fos and NFATc1 were determined by Western blot analysis.

RESULTS

Implantation of HKLr onto the mouse calvaria induced the bone destruction with an increase of TRAP-positive areas. While HKLr enhanced the differentiation of osteoclasts, this effect was not observed in TLR2-deficient osteoclasts. HKLr dose-dependently increased the mRNA expression of genes associated with osteoclast differentiation including TRAP, ATPase H+ transporting V0 subunit D2, and cathepsin K. In addition, HKLr enhanced the expression of c-Fos and NFATc1, which are important transcription factors for osteoclast differentiation. Moreover, HKLr increased the expression of interleukin-6 and tumor necrosis factor-α.

CONCLUSION

L. rimae induces bone resorption by enhancing osteoclast differentiation through the TLR2 signaling pathway, implying that L. rimae is a causative agent responsible for the alveolar bone resorption accompanying apical periodontitis.

Can periodontitis affect the COVID-19 severity, symptoms, hospital stay, and mortality? A case-control study

Background/purpose

Poor oral hygiene and periodontal disease have been identified as potential risk factors for the coronavirus disease 2019 (COVID-19). The present study aimed to determine the association between periodontitis and COVID-19 severity, nature of symptoms, mortality, and hospital stay.

Methods

In total, 163 COVID-19-positive patients (men: 93; women: 70) were categorized into two groups: the control group, consisting of 120 patients with asymptomatic or mild symptoms, and the case group, consisting of 43 patients with moderate-to-severe symptoms. The severity of periodontal disease, oral hygiene status (OHI), pocket depth (PD), bleeding on probing (BOP), number of decayed/missing/filled teeth, mortality, duration of stay in the hospital, oxygen requirement, and nature of COVID-19 symptoms were assessed in both groups. The association between periodontitis and COVID-19 was analyzed with other confounding factors such as age, sex, comorbidities, oral hygiene, and smoking status.

Results

The presence of periodontitis increases the severity of COVID-19 by 3.7 times (p = 0.002). A statistically significant difference was noted for symptoms such as dizziness (p = 0.036), running nose/cold (p = 0.009), and headache (p = 0.005) in the presence of periodontitis. The risk estimate for death associated with periodontitis was 1.03. Additionally, the average duration of stay was longer for individuals with periodontitis than for those in the control group.

Conclusion

There is a positive association between periodontal disease and COVID-19. Periodontitis increases the severity of COVID-19 and alters the symptoms. Hence, periodontal disease management should be an integral part of managing patients with coronavirus infection.

GPR40/GPR120 Agonist GW9508 Improves Metabolic Syndrome-Exacerbated Periodontitis in Mice

G protein-coupled receptor (GPR)40 and GPR120 are receptors for medium- and long-chain free fatty acids. It has been well documented that GPR40 and GPR120 activation improves metabolic syndrome (MetS) and exerts anti-inflammatory effects. Since chronic periodontitis is a common oral inflammatory disease initiated by periodontal pathogens and exacerbated by MetS, we determined if GPR40 and GPR120 activation with agonists improves MetS-associated periodontitis in animal models in this study. We induced MetS and periodontitis by high-fat diet feeding and periodontal injection of lipopolysaccharide, respectively, and treated mice with GW9508, a synthetic GPR40 and GPR120 dual agonist. We determined alveolar bone loss, osteoclast formation, and periodontal inflammation using micro-computed tomography, osteoclast staining, and histology. To understand the underlying mechanisms, we further performed studies to determine the effects of GW9508 on osteoclastogenesis and proinflammatory gene expression in vitro. Results showed that GW9508 improved metabolic parameters, including glucose, lipids, and insulin resistance. Results also showed that GW9508 improves periodontitis by reducing alveolar bone loss, osteoclastogenesis, and periodontal inflammation. Finally, in vitro studies showed that GW9508 inhibited osteoclast formation and proinflammatory gene secretion from macrophages. In conclusion, this study demonstrated for the first time that GPR40/GPR120 agonist GW9508 reduced alveolar bone loss and alleviated periodontal inflammation in mice with MetS-exacerbated periodontitis, suggesting that activating GPR40/GPR120 with agonist GW9508 is a potential anti-inflammatory approach for the treatment of MetS-associated periodontitis.

Evaluation of adherence of Candida albicans to differently manufactured acrylic resin denture base materials

STATEMENT OF PROBLEM

Though computer-aided design and computer-aided manufactured (CAD-CAM) denture bases have become popular, evidence on the ability of C. albicans cells to adhere to these denture bases is lacking.

PURPOSE

The purpose of this in vitro study was to evaluate the adherence of Candida albicans to differently manufactured acrylic resin denture bases.

MATERIAL AND METHODS

Acrylic resin disks were fabricated using a total of 6 different fabrication methods (compression molding, injection molding, CAD-CAM milling, and rapid prototyping on 3 different printers with 3 different resins). Each material was evaluated for adherence of C. albicans using 2 different experimental methods - suspension in inoculated tryptic soy broth (TSB) or placed onto a uniform lawn of C. albicans on tryptone soya agar (TSA) with 5% sheep's blood. Attached cells were quantified by spiral plating and then used to re-inoculate sterile plates. Logarithmic transformation was completed to normalize data. For the broth suspension, the Kruskal-Wallis test was used to identify any differences between the 6 specimen types in terms of recovery, and the Dunn test was used for post hoc analysis. For the microbial lawn experiment, 1-way analysis of variance (ANOVA) and then the Tukey Honestly Significant Difference (HSD) post hoc test were used.

RESULTS

Statistically significant differences were found between the numbers of adherent cells based on manufacturing method and between experimental designs (P<.05). All resins demonstrated growth with re-inoculation.

CONCLUSIONS

Though statistical significance was noted, neither experimental technique demonstrated what is likely a clinically significant preferential binding to any particular resin surface. Attached Candida cells are effective carriers of pathogens to uninfected surfaces. Further studies are indicated for potential virulence factors and differences in printed resins.

Chitosan and liposomal delivery systems for epicatechin or propyl gallate targeting localized treatment of vulvovaginal candidiasis

Natural polyphenols are promising alternatives to antifungals for novel treatments of vulvovaginal candidiasis (VVC) in an era of antimicrobial resistance. However, polyphenols are poorly soluble and prone to degradation. To overcome their limitations, we propose incorporation in liposomes. The study aimed to develop chitosan and liposome comprising delivery systems for epicatechin (EC) or propyl gallate (PG) as treatment of VVC. EC was selected for its antioxidative properties and PG as an ester of antifungal gallic acid. To improve formulation retention at vaginal site, mucoadhesive chitosan was introduced into formulation as liposomal surface coating or hydrogel due to intrinsic antifungal properties. These polyphenol-loaded liposomes exhibited an average size of 125 nm with a 64 % entrapment efficiency (for both polyphenols). A sustained in vitro polyphenol release was seen from liposomes, particularly in chitosan hydrogel (p < 0.01 or lower). Viscosity was evaluated since increased viscosity upon mucin contact indicated adhesive bond formation between chitosan and mucin confirming mucoadhesiveness of formulations. Antifungal activity was evaluated by the broth microdilution method on Candida albicans CRM-10231. Unlike PG, incorporation of EC in liposomes enabled antifungal activity. Fungicidal activity of chitosan was confirmed both when used as liposomal coating material and as hydrogel vehicle.

Productions of Th2 cytokines, IL-4 and IL-10, were enhanced via the function of IL-2 from anti-CD3 antibody-stimulated mouse spleen cells treated with caffeic acid phenethyl ester

OBJECTIVES

Interleukin (IL)-2 production by mouse spleen cells stimulated with an anti-CD3 antibody is significantly enhanced by caffeic acid phenethyl ester (CAPE), a major constituent of Chinese propolis (CP). In this study, we evaluated the functional significance of IL-2 in CAPE-treated activated spleen cells.

METHODS

Mouse spleen cells were stimulated with an anti-CD3 monoclonal antibody in the presence of CAPE. Cytokine production was examined using an enzyme-linked immunosorbent assay (ELISA). Messenger RNA level expression was examined via reverse transcription quantitative polymerase chain reaction (RT-PCR). IL-2 function was assessed using IL-2 and a neutralizing antibody. Spleen cell subsets were identified and characterized using flow cytometry.

RESULTS

CAPE treatment of anti-CD3 antibody-stimulated spleen cells reduced IFN-γ production, then enhanced IL-2 production, followed by enhancement of IL-4 and IL-10 production. The Th2 cytokine production enhancing effects of CAPE were completely abolished by addition of an anti-IL-2 neutralizing antibody. In the absence of CAPE, exogenously added IL-2 could enhance IL-4 production to a lesser degree, but did not stimulate IL-10 production, in stimulated spleen cells. Interestingly, CAPE significantly reduced the proportions of CD4+ and CD8+ cells, and increased those of CD4-CD8- cells among anti-CD3 stimulated spleen cells, in the presence or absence of anti-IL-2 neutralizing antibody treatment.

CONCLUSIONS

CAPE reduced IFN-γ production, then enhanced IL-4 and IL-10 production via the activity of specifically elevated IL-2 in stimulated spleen cells. CAPE exerted these effects in a CD4- CD8- cell specific manner.

Revolutionizing Bone Regeneration with Grinder-Based Dentin Biomaterial: A Systematic Review

Bone tissue regeneration is a critical aspect of dental surgery, given the common occurrence of bone resorption leading to alveolar bone defects. The aim of this paper was to conduct a systematic review to provide a comprehensive summary of the evidence regarding the regenerative properties of dentin biomaterial. This systematic review was conducted through comprehensive searches in the PubMed, Scopus, and Web of Science databases, as well as an extensive exploration of the gray literature sources, including WorldCat, The New York Academy of Medicine Library, and Trip Database, following the established PRISMA protocol. Keywords such as tooth, dentin, grinder, and autograft guided the search, with a focus on a standardized procedure involving dentin grinders within laboratory, experimental, and clinical settings. Initially, a pool of 1942 articles was identified with 452 duplicates removed. An additional 1474 articles were excluded for not aligning with the predefined topics, and three more were excluded due to the unavailability of the full text. Ultimately, 13 articles met the strict inclusion criteria and were included in the review. The chemical composition of the dentin particles was similar to natural bone in terms of oxygen, carbon, calcium, phosphorus, sodium, and magnesium content, as well as in terms of the Ca/P ratio. In addition, the dentin also contained amide I and amide II structures, as well as aliphatic and hydroxyl functional groups. The chemically treated dentin was free of microorganisms. The dentin had characteristic tubules that opened after chemical treatment. At the cellular level, dentin released bone morphogenetic protein 2, induced significant cell growth, and stimulated the reorganization of the fibroblast cytoskeleton. Most clinical studies have focused on alveolar bone regeneration. After the transplantation of demineralized dentin particles, studies have observed new bone formation, a reduction in residual bone, and an increase in connective tissue. Clinical reports consistently indicate uncomplicated healing and recovery post-transplantation. However, there is a notable gap in the evidence concerning complication rates, patient-reported outcomes, and the presence of pro-inflammatory factors. In conclusion, dentin biomaterial emerges as a versatile bone substitute, demonstrating high biocompatibility and ease of acquisition. The preservation of its internal structure containing organic matter and growth factors enhances its potential for effective bone regeneration. Particularly, in dental surgery, dentin-derived materials present a promising alternative to traditional autologous bone autografts, offering the potential to reduce patient morbidity and treatment costs.

Animal models and related techniques for dentin study

The intricate and protracted process of dentin formation has been extensively explored, thanks to the significant advancements facilitated by the use of animal models and related techniques. Despite variations in their effectiveness, taking into account factors such as sensitivity, visibility, and reliability, these models or techniques are indispensable tools for investigating the complexities of dentin formation. This article focuses on the latest advances in animal models and related technologies, shedding light on the key molecular mechanisms that are essential in dentin formation. A deeper understanding of this phenomenon enables the careful selection of appropriate animal models, considering their suitability in unraveling the underlying molecular intricacies. These insights are crucial for the advancement of clinical drugs targeting dentin-related ailments and the development of comprehensive treatment strategies throughout the duration of the disease.

A nontoxic strontium nanoparticle that holds the potential to act upon osteocompetent cells: An in vitro and in vivo characterization

Estrogen deficiency, long-term immobilization, and/or aging are commonly related to bone mass loss, thus increasing the risk of fractures. One option for bone replacement in injuries caused by either traumas or pathologies is the use of orthopedic cement based on polymethylmethacrylate (PMMA). Nevertheless, its reduced bioactivity may induce long-term detachment from the host tissue, resulting in the failure of the implant. In view of this problem, we developed an alternative PMMA-based porous cement (pPMMA) that favors cell invasion and improves osteointegration with better biocompatibility. The cement composition was changed by adding bioactive strontium-nanoparticles that mimic the structure of bone apatite. The nanoparticles were characterized regarding their physical-chemical properties, and their effects on osteoblasts and osteoclast cultures were assessed. Initial in vivo tests were also performed using 16 New Zealand rabbits as animal models, in which the pPMMA-cement containing the strontium nanoparticles were implanted. We showed that the apatite nanoparticles in which 90% of Ca2+ ions were substituted by Sr2+ (NanoSr 90%) upregulated TNAP activity and increased matrix mineralization. Moreover, at the molecular level, NanoSr 90% upregulated the mRNA expression levels of, Sp7, and OCN. Runx2 was increased at both mRNA and protein levels. In parallel, in vivo tests revealed that pPMMA-cement containing NanoSr 90%, upregulated two markers of bone maturation, OCN and BMP2, as well as the formation of apatite minerals after implantation in the femur of rabbits. The overall data support that strontium nanoparticles hold the potential to up-regulate mineralization in osteoblasts when associated with synthetic biomaterials.

Candida species in periodontitis: A new villain or a new target?

OBJECTIVES

Recent research indicated that fungi might have a role in periodontitis alongside traditional periodontal pathogens. This state-of-the-art narrative review explores current concepts on the involvement of Candida species in periodontitis, and suggests the potential for ecological management of this disease.

DATA, SOURCES AND STUDY SELECTION

A literature search was conducted for a narrative review on Web of Science, PubMed, Medline and Scopus about periodontitis associated with Candida species. Published articles, including case reports, case series, observational and interventional clinical trials, and critical appraisals of the literature were retrieved and reviewed.

CONCLUSIONS

Several factors predispose individuals to periodontitis associated with Candida species. These include systemic diseases that lead to immunosuppression and oral environment changes such as cigarette smoking. While a consistent significant increase in the detection rate of Candida species in patients with periodontitis has not been universally observed, there is evidence linking Candida species to the severity of periodontitis and their potential to worsen the condition. Candida species may participate in the development of periodontitis in various ways, including cross-kingdom interactions with periodontal pathogens, changes in the local or systemic environment favoring the virulence of Candida species, and interactions between Candida-bacteria and host immunity.

CLINICAL SIGNIFICANCE

Mechanical plaque control is the most common treatment for periodontitis, but its effectiveness may be limited, particularly when dealing with systemic risk factors. Understanding the specific role of Candida in periodontitis illuminates innovative approaches for managing the ecological balance in periodontal health.

Bifunctional naringenin-laden gelatin methacryloyl scaffolds with osteogenic and anti-inflammatory properties

OBJECTIVE

To fabricate and characterize an innovative gelatin methacryloyl/GelMA electrospun scaffold containing the citrus flavonoid naringenin/NA with osteogenic and anti-inflammatory properties.

METHODS

GelMA scaffolds (15 % w/v) containing 0/Control, 5, 10, or 20 % of NA w/w were obtained via electrospinning. The chemical composition, fiber morphology/diameter, swelling/degradation profile, and NA release were investigated. Cytotoxicity, cell proliferation, adhesion and spreading, total protein/TP production, alkaline phosphatase/ALP activity, osteogenic genes expression (OCN, OPN, RUNX2), and mineralized nodules deposition/MND with human alveolar bone-derived mesenchymal stem cells (aBMSCs) seeded on the scaffolds were assessed. Moreover, aBMSCs seeded on the scaffolds and stimulated with tumor necrosis factor-alpha/TNF-α were submitted to collagen, nitric oxide/NO, interleukin/IL-1α, and IL-6 production assessment. Data were analyzed using ANOVA and t-student/post-hoc tests (α = 5 %).

RESULTS

NA-laden scaffolds presented increased fiber diameter, lower swelling capacity, and faster degradation profile over 28 days (p < 0.05). NA release was detected over time. Cell adhesion and spreading, and TP production were similar between GelMA and GelMA+NA5 % scaffolds, while cell proliferation, ALP activity, OCN/OPN/RUNX2 gene expression, and MND were higher for GelMA+NA5 % scaffolds (p < 0.05). Cells seeded on control scaffolds and TNF-α-stimulated presented higher levels of NO, IL-1α/IL-6, and lower levels of collagen (p < 0.05). In contrast, cells seeded on GelMA+NA5 % scaffolds showed downregulation of inflammatory markers and higher collagen synthesis (p < 0.05).

SIGNIFICANCE

GelMA+NA5 % scaffold was cytocompatible, stimulated aBMSCs proliferation and differentiation, and downregulated inflammatory mediators' synthesis, suggesting its therapeutic effect as a multi-target bifunctional scaffold with osteogenic and anti-inflammatory properties for bone tissue engineering.

Regional difference in the distribution of alkaline phosphatase, PHOSPHO1, and calcein labeling in the femoral metaphyseal trabeculae in parathyroid hormone-administered mice

OBJECTIVES

This study aimed to elucidate whether the administration of parathyroid hormone (PTH) results in remodeling- or modeling-based bone formation in different regions of the murine femora, and whether the PTH-driven bone formation would facilitate osteoblastic differentiation into osteocytes.

METHODS

Six-week-old male C57BL/6J mice were employed to examine the distribution of alkaline phosphatase (ALP), PHOSPHO1, podoplanin, and calcein labeling in two distinct long bone regions: the metaphyseal trabeculae close to the chondro-osseous junction (COJ) and those distant from the COJ in three mouse groups, a control group receiving a vehicle (sham group) and groups receiving hPTH (1-34) twice a day (PTH BID group) or four times a day (PTH QID group) for two weeks.

RESULTS

The sham group showed PHOSPHO1-reactive mature osteoblasts localized primarily at the COJ, whereas the PTH BID/QID groups exhibited extended lines of PHOSPHO1-reactive osteoblasts even in regions distant from the COJ. The PTH QID group displayed fragmented calcein labeling in trabeculae close to the COJ, whereas continuous labeling was observed in trabeculae distant from the COJ. Osteoblasts tended to express podoplanin and PHOSPHO1 independently in the close and distant regions of the sham group, while osteoblasts in the PTH-administered groups showed immunoreactivity of podoplanin and PHOSPHO1 together in the close and distant regions.

CONCLUSIONS

Administration of PTH may accelerate remodeling-based bone formation in regions close to the COJ while predominantly inducing modeling-based bone formation in distant regions. PTH appeared to simultaneously facilitate osteoblastic bone mineralization and differentiation into osteocytes in both remodeling- and modeling-based bone formation.

Assessing the existence of the male-female health-survival paradox in the past: Dental caries in medieval London

OBJECTIVES

This study seeks to identify signals of the male-female health-survival paradox in medieval London.

MATERIALS AND METHODS

This study uses skeletal data on age, sex, dental caries (n = 592) and antemortem tooth loss (n = 819) from adult individuals from medieval London cemeteries (c. 1200-1540 CE). The association between age and dental caries was assessed using binary logistic regression. The associations among age, time period (pre- vs. post-Black Death), oral biomarker (dental caries or antemortem tooth loss), and sex were tested using hierarchical log-linear analysis.

RESULTS

The analyses reveal significantly higher odds of dental caries with increasing adult ages, more older adults after the Black Death, different age distributions of dental caries between the sexes, and a greater decrease in the prevalence of dental caries for females after the Black Death. These results appear not to be an artifact of trends in AMTL. However, this study does not yield evidence suggesting that females experienced both a survival advantage and a decline in oral health at late adult ages after the Black Death relative to males.

CONCLUSIONS

These results do not provide evidence of the existence of a male-female health-survival paradox, but they do corroborate existing evidence of improvements in health in general in the aftermath of the Black Death. The decreased prevalence of dental caries after the Black Death may reflect dietary improvements or the effects of selective mortality during the epidemic.

Pathogenic mechanisms in genetically defined Ehlers-Danlos syndromes

The Ehlers-Danlos syndromes (EDS) are a group of rare heritable connective tissue disorders, common hallmarks of which are skin hyperextensibility, joint hypermobility, and generalized connective tissue fragility. Currently, 13 EDS types are recognized, caused by defects in 20 genes which consequently alter biosynthesis, organization, and/or supramolecular assembly of collagen fibrils in the extracellular matrix (ECM). Molecular analyses on patient samples (mostly dermal fibroblast cultures), combined with studies on animal models, have highlighted that part of EDS pathogenesis can be attributed to impaired cellular dynamics. Although our understanding of the full extent of (extra)cellular consequences is still limited, this narrative review aims to provide a comprehensive overview of our current knowledge on the extracellular, pericellular, and intracellular alterations implicated in EDS pathogenesis.

Diurnal fluctuations in biochemical parameters related to calcium homeostasis - the Bispebjerg study of diurnal variations

PURPOSE

This aim of this study was to assess the possible association between diurnal oscillations and biochemical markers associated with calcium homeostasis. This included the markers parathyroid hormone (PTH), total calcium, total alkaline phosphatase, phosphate, and 25-hydroxyvitamin D (25-OH-D). By examining the influence of circadian rhythms on these parameters, the study aimed to deepen the understanding of calcium metabolism dynamics and its clinical implications.

PATIENTS AND METHODS

Blood samples from 24 Caucasian male volunteers aged 20 to 40 (mean age 26) with normal pulse, blood pressure, and BMI were analyzed for biochemical markers related to calcium homeostasis. Data was obtained from the Bispebjerg study of diurnal variations. Blood samples were collected every three hours over a 24-hour period. Patients were fasting from 22:00 to 09:00. The participants spent 24 h in the hospital ward, receiving regular meals and engaging in low-intensity activities. They experienced 15 h of daylight and 9 h of complete darkness during sleep. Diurnal oscillations were analyzed using cosinor analysis with statistical significance set at p < 0.05.

RESULTS

Total calcium, phosphate, and PTH exhibited significant diurnal variations. Total calcium and PTH were inversely synchronized while PTH and phosphate oscillated in synchronization. The three parameters showed relatively large amplitude/reference range ratios from 25.4% to 41.5%.

CONCLUSION

This study found notable fluctuations in total calcium, phosphate, and PTH levels over a 24-hour cycle, while 25-OH-D and total alkaline phosphatase remained consistent. It highlights the importance of considering sampling times for total calcium, PTH, and phosphate in clinical settings.

Efficacy of adjunctive local periodontal treatment for type 2 diabetes mellitus patients with periodontitis: A systematic review and network meta-analysis

OBJECTIVES

To investigate the effectiveness of different adjunctive local treatments combined with non-surgical periodontal therapy (NSPT) to reduce pocket depth (PD), gain clinical attachment level (CAL), and/or reduce glycated hemoglobin (HbA1c) in individuals with both type 2 diabetes mellitus (T2DM) and periodontitis in a systematic review and network meta-analysis.

DATA SOURCES

Publications were searched in Cochrane databases, EMBASE, Google Scholar, MEDLINE, PubMed, opengrey.eu, and www.

CLINICALTRIALS

gov up to May 29, 2024 with no language restriction.

STUDY SELECTION

Only randomized controlled trials (RCTs) were included. Network meta-analysis utilized frequentist models.

DATA

The network meta-analysis of 30 RCTs involving 1224 patients revealed that, in short-term (2-3 months) and medium-term (4-6 months), adjunctive local treatment involving statins or metformin significantly outperformed scaling and root planning (SRP) with/without additional interventions such as photodynamic and laser therapies (PDT/LT), phytotherapy, doxycycline, bisphosphonates, antibiotics, antiseptics, or placebo for reducing PD and/or gaining CAL. In the long-term (>6 months), statins yielded the most significant additional PD reduction and CAL gain, followed by antibiotics, compared to SRP with antiseptics or placebo. Only PDT/LT demonstrated significantly greater HbA1c reduction in the short term compared to SRP with/without statins, antiseptics, or placebo.

CONCLUSION

This study moderately supports that adding metformin or statins locally to NSPT may enhance PD reduction and CAL gain compared to SRP with/without placebo.

CLINICAL SIGNIFICANCE

Clinicians are guided to optimize adjunctive therapies, enhancing the health of patients with type 2 diabetes and periodontitis. A strategic approach is proposed to tackle systemic and oral health challenges simultaneously.

Three-dimensional volumetric assessment and stability of simultaneously placed implant following sinus floor augmentation with deproteinized human demineralized tooth matrix or deproteinized bovine bone mineral: a randomized controlled clinical trial

PURPOSE

This study aimed to analyze and compare three-dimensional volumetric bone changes and stability of simultaneously placed dental implants following sinus augmentation using deproteinized human demineralized tooth matrix (dpDTM) and deproteinized bovine bone mineral (DBBM).

METHODS

Twenty-four patients who required lateral maxillary sinus floor augmentation with simultaneous dental implant placement were randomly assigned to receive either dpDTM (n = 12) or DBBM (n = 12). Cone-beam computed tomography and resonance frequency analysis of implant stability were conducted immediately after surgery and 6 months postoperatively. Changes in the graft sinus floor and graft height volumes in the sagittal and coronal views, along with the implant stability quotient (ISQ), were analyzed and compared.

RESULTS

Volumetric graft alteration was comparable between dpDTM (120.33 ± 77.48 mm3) and DBBM (108.51 ± 65.15 mm3) (p = 0.690). Reduction in the average graft height was also comparable: dpDTM group ranged from - 0.59 to - 0.93 mm and the DBBM group ranged from - 0.55 to - 0.82 mm (p > 0.05) at most examined levels. However, greater reduction in the mesial-graft height occurred in the dpDTM group (- 1.08 ± 0.70 mm vs. -0.58 ± 0.39 mm, p = 0.04). The ISQ values increased similarly in both groups to reach 70 at 6 months.

CONCLUSION

dpDTM demonstrated comparable stability in graft volume and height during the healing process compared to DBBM and could serve as a viable alternative to DBBM for sinus floor augmentation with simultaneous implant placement.

In silico analysis of DEL-1 and inflammation-related genes in lung squamous cell carcinoma

AIM

Twenty to thirty percent of non-small cell lung cancers (NSCLC) are caused by lung squamous cell carcinoma (LUSC), especially in smokers and there has been limited study previously evaluating the situation in terms of the genome and gene expression profile, which demonstrates the relationship among DEL-1, leucocyte recruitment, and pro-inflammatory cytokines in LUSC.

MATERIAL AND METHODS

In the current study, the m-RNA expression patterns and mutation profiles of our target genes, such as, pro-inflammatory cytokines, chemoattractant molecules, and DEL-1 genes, in 511 LUSC patients. To find the harmful mutations, the PolyPhen-2 and SNAP programs were employed. Not only gene expression was detected, but also survival analysis and correlation between DEL-1 and other target genes' expression levels were explored too.

RESULTS

Target genes such as, DEL-1, TNF, IL-18, IL-1, CXCL8, CXCL13, and IL-6 were found to have a total genetic anomaly carrying rate of 16.4%. Seven mutations were found, and two of those mutations have a pathogenic aspect. Deep deletion and gene amplification of the genetic anomalies were also observed. According to gene expression analysis results in the LUSC patient group; DEL-1 and IL-6 levels were significantly lower than those of the control group, whereas the CXCL13 level was found to be higher.

CONCLUSION

Findings of the current study revealed that, there is a significant role of DEL-1 in LUSC pathogenesis. Since present study is an in silico-centered study, this approach can give more insight on experimental studies. These events may support that one of the cancer improvement mechanisms depending on DEL-1 gene at the molecular level.

Scent of relief: Mastic resin scent recovers salivation in chronic dry mouth patients

BACKGROUND

Olfactory stimulation with mastic resin, derived from the Pistacia lentiscus tree, demonstrated a bona fide sialagogic effect in healthy volunteers [1]. Its main volatile compound, α-pinene, also showed this effect. The current study aimed to validate the effect of mastic resin volatiles in chronic dry mouth patients with confirmed decreased saliva secretion.

METHODS

41 chronic dry mouth patients with decreased unstimulated saliva secretion (<0.25 mL/min) were exposed to mastic resin volatiles as part of the diagnostic routine at the Saliva Clinic of Academic Centre for Dentistry Amsterdam. During their visit, dry-mouth questionnaires were conducted and samples of unstimulated whole saliva, chew-stimulated saliva, acid-stimulated saliva and mastic resin stimulated saliva were collected. Saliva flow rate, spinnbarkeit, pH, ion composition, MUC5B and MUC7 levels in all samples were analyzed.

RESULTS

Salivary flow rates increased by all stimuli when compared to the baseline unstimulated saliva (P<0.001). During olfactory mastic resin stimulation, the salivary spinnbarkeit (P<0.001) and sodium concentration (P<0.01) were increased compared to unstimulated saliva. MUC5B and MUC7 levels were increased during olfactory mastic resin stimulation compared to chew-stimulated saliva (P=0.016 and P<0.001, respectively). Spinnbarkeit correlated positively with MUC5B (R=0.399, P=0.002) and MUC7 levels (R=0.375, P=0.004). Results of dry-mouth questionnaires indicated reduced posterior palate dryness shortly after olfactory mastic resin stimulation (P=0.04).

CONCLUSIONS

Olfactory mastic resin stimulation increased mucous saliva secretion and reduced posterior palate dryness in a group of chronic dry mouth patients. These findings, validated in patients, underscore mastic resin scent as a beneficial and non-invasive sialagogic treatment for clinical applications.

Dysgeusia and Chronic Kidney Disease: A Scoping Review

Dysgeusia is a common altered taste perception in chronic kidney disease patients. The study aims to identify available treatments for educating, screening, and clinically managing dysgeusia in this population. A scoping review was conducted following the protocol of Arksey and O'Malley, incorporating the Joanna Briggs Institute methodology, and adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews guidelines. Among the 424 identified records, 13 studies were included. Screening methodologies, educational strategies, particularly a hospital-based program focusing on salt reduction, showed a significant improvement in dysgeusia (P < .001). The identified clinical treatments exclusively included oral zinc supplementation, with dosages ranging from 50 to 220 mg, reporting heterogeneous results not consistent across different studies. The personalized management of dysgeusia associated with chronic kidney disease is crucial, requiring targeted education and treatment protocols to prevent and address nutritional complications such as malnutrition.

The relevance of taurodontism in forensic dental age estimation

Taurodontism is a dental morphological anomaly characterized by enlarged pulp cavities repositioned towards the apical region of the tooth, coupled with shortened root structures. Molars are commonly affected by this alteration. Certain populations exhibit up to 48% prevalences for this dental alteration, underscoring its significance in dental age estimation (DAE). In the field of DAE, an individual's chronological age is inferred from specific dental features, frequently employed within the forensic context. The effect of taurodontism on the features of DAE is an unanswered issue. The influence of taurodontism on eruption, mineralization, radiographic visibility of root canals, and radiographic visibility of the periodontal ligament space in mandibular third molars- some of the established criteria for DAE as examples-is currently not systematically examined. Some common staging scales for the dental features of DAE cannot technically be applied to taurodontic teeth. Additionally, given the association of taurodontism with syndromes affecting tooth development, caution is warranted in age assessment procedures. Notably, taurodontic teeth may serve as indicators of syndromes influencing skeletal development, further emphasizing the relevance of taurodontism in forensic age assessment. Presumably taurodontic teeth were included in reference data to some extent due to their partially high prevalence in the past, whereby the influence of taurodontism has been statistically absorbed within the overall spread of the features. Future studies should compare the temporal course of these tooth characteristics in affected and unaffected teeth. Subsequent initiatives should focus on raising awareness among forensic dentists regarding taurodontism, necessitating in-depth exploration of the subject.

A millimetre-scale capacitive biosensing and biophysical stimulation system for emerging bioelectronic bone implants

Bioelectronic bone implants are being widely recognized as a promising technology for highly personalized bone/implant interface sensing and biophysical therapeutic stimulation. Such bioelectronic devices are based on an innovative concept with the ability to be applied to a wide range of implants, including in fixation and prosthetic systems. Recently, biointerface sensing using capacitive patterns was proposed to overcome the limitations of standard imaging technologies and other non-imaging technologies; moreover, electric stimulation using capacitive patterns was proposed to overcome the limitations of non-instrumented implants. We here provide an innovative low-power miniaturized electronic system with ability to provide both therapeutic stimulation and bone/implant interface monitoring using network-architectured capacitive interdigitated patterns. It comprises five modules: sensing, electric stimulation, processing, communication and power management. This technology was validated using in vitro tests: concerning the sensing system, its ability to detect biointerface changes ranging from tiny to severe bone-implant interface changes in target regions was validated; concerning the stimulation system, its ability to significantly enhance bone cells' full differentiation, including matrix maturation and mineralization, was also confirmed. This work provides an impactful contribution and paves the way for the development of the new generation of orthopaedic biodevices.

Roles of SP/KLF transcription factors in odontoblast differentiation: From development to diseases

OBJECTIVES

A zinc-finger transcription factor family comprising specificity proteins (SPs) and Krüppel-like factor proteins (KLFs) plays an important role in dentin development and regeneration. However, a systematic regulatory network involving SPs/KLFs in odontoblast differentiation has not yet been described. This review examined the expression patterns of SP/KLF gene family members and their current known functions and mechanisms in odontoblast differentiation, and discussed prospective research directions for further exploration of mechanisms involving the SP/KLF gene family in dentin development.

MATERIALS AND METHODS

Relevant literature on SP/KLF gene family members and dentin development was acquired from PubMed and Web of Science.

RESULTS

We discuss the expression patterns, functions, and related mechanisms of eight members of the SP/KLF gene family in dentin development and genetic disorders with dental problems. We also summarize current knowledge about their complementary or synergistic actions. Finally, we propose future research directions for investigating the mechanisms of dentin development.

CONCLUSIONS

The SP/KLF gene family plays a vital role in tooth development. Studying the complex complementary or synergistic interactions between SPs/KLFs is helpful for understanding the process of odontoblast differentiation. Applications of single-cell and spatial multi-omics may provide a more complete investigation of the mechanism involved in dentin development.

Association of gut microbiome and oral cavity cancer: A two sample mendelian randomization and case-control study

INTRODUCTION

Considering the interconnectedness of the oral cavity and gut tract and the presence of abundant natural microbiota in both. We utilized Mendelian Randomization (MR) in a two-sample study to unveil the genetic causal impact of gut microbiota on the development of oral cavity cancer.

MATERIALS & METHODS

The instrumental variables employed in this study consisted of single nucleotide polymorphisms (SNPs) that demonstrated a robust association with 211 distinct gut microbiota taxa, encompassing a sample size of 18,340 individuals. Our investigation sought to explore the potential causal relationship between these genetic variants and the incidence of oral cavity cancer. To accomplish this, we adopted a random effect inverse variance-weighted approach to analyze the causal effect. Additionally, sensitivity analyses were performed utilizing Cochran's Q tests, funnel plots, leave-one-out analyses, and MR-Egger intercept tests, to assess the robustness and validity of our findings.

RESULTS

Five gut microbiota taxa (the family Prevotellaceae, the genus Alloprevotella, the genus Erysipelatoclostridium, the genus Parabacteroides, the genus Ruminococcus gauvreauii group) are predicted to play a causal role in promoting the initiation of the risk of oral cavity cancer. While the genus Christensenellaceae R 7 group, the genus Intestinimonas, the genus Ruminococcaceae, and the order Bacillales causally reduce the risk of oral cavity cancer. Furthermore, no significant evidence suggesting heterogeneity or pleiotropy was observed.

DISCUSSION

The novel genetic causal effects of 211 gut microbiota taxa on oral cavity cancer are elucidated in this investigation, thus offering valuable insights for clinical interventions targeting oral cavity cancer.

Identifying teeth and tooth fragments from digital 3D models

Dental anatomy is an essential skill for human identification in forensic odontology. With the advent of technology enabling virtual autopsies, there is scope for virtual consultation by forensic odontologists especially when the expertise is unavailable but needed in zones of conflict or disasters. This study aimed to investigate potential benefits and challenges of identifying intact and damaged teeth from 3D scanned digital models. Ten 3D tooth models - nine permanent and deciduous human teeth and one animal tooth were uploaded on a hosting platform. A 3-part survey was circulated among 60 forensic odontologists with questions about demography (P1), tooth identification of the scanned 3D models (P2) and the perceived usefulness of 3D models for tooth identification (P3). This was the first time that a survey required the identification of individual human teeth (intact or not) and animal tooth combined. The response rate for study participation was 58%. Substantial agreement among participants was seen in the determination of tooth classification (i.e., molars, premolars) or non-human and tooth within the same tooth class (i.e., lateral incisors, second molar) (both k=0.61). The least agreement (k=0.21) was seen in identification of tooth according to the FDI notation with a mean accuracy of 0.34. While most responders correctly identified the animal tooth, most incorrect responses were seen in the identification of the intact third molar. While 3D-scanned teeth have the potential to be identified virtually, forensic odontologists should continuously test their skills in tooth morphology and dental anatomy of humans (damaged or not) and animals.

Molecular microbiological profiling of bottled unsweetened tea beverages: A screening experiment

To explore the potential storage and safety of drinking leftover bottled tea beverages from various manufacturers after direct drinking from bottles, we conducted a screening experiment on the growth of salivary bacteria in plastic bottles of tea. The diluted saliva samples from 10 participants were inoculated into the test bottled beverages, which resulted in bacteria, particularly former members of the genus Lactobacillus, growing in some green tea beverages with a neutral pH. In contrast, tea beverages with less bacterial growth contained Streptococcus spp., and the leftovers may be safe to store and drink again.

Epoxy resin bioactive dental implant capped with hydroxyapatite and curcumin nanoparticles: a novel approach

OBJECTIVE

In this study, the developed bioactive dental implant (BDI) from epoxy resin (ER), hydroxyapatite (HA), and curcumin nanoparticles (CUNPs).

MATERIALS AND METHODS

The prepared BDI were characterized using their physicochemical, mechanical, antimicrobial, bioactive, and biocompatibility study. The scanning electron microscopy (SEM) morphology of the BDI was observed HA mineralized crystal layer after being immersed in the stimulated body fluids (SBF) solution.

RESULTS

The mechanical properties of the BDI exhibited tensile strength (250.61 ± 0.43 MPa), elongation at break (215.66 ± 0.87%), flexural modulus (03.90 ± 0.12 GPa), water absorption (05.68 ± 0.15%), and water desorption (06.42 ± 0.14%). The antimicrobial activity of BDI was observed in excellent zone of inhibition against the gram-negative (15.33 ± 0.04%) and gram- positive (15.98 ± 0.07%) bacteria. The biocompatibility study of BDI on osteoblasts cell line (MG-63) was analyzed using MTT (3-[4, 5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay. The results were observed 85% viable cells present in the BDI compared to the control (only ER) samples.

CONCLUSIONS

Based on the research outcome, the BDI could be used for biomaterials application, particularly tooth dental implantation.

A probable case of hypophosphatasia in St Bride's Lower Churchyard (1770-1849, London, UK)

OBJECTIVES

The objective of this study was to analyse an individual whose remains are characterised by early deciduous tooth loss and multi-focal lesions on the post-cranial skeleton.

MATERIALS

Skeletal remains of an immature individual buried between 1770 and 1849 in London.

METHODS

The remains were examined by visual macroscopic inspection, supplemented by radiographic examination of the mandible and maxillae. A differential diagnosis with possible conditions, frequent in this archaeological context, was conducted. A comprehensive examination of dental lesions was performed to investigate the aetiologies of deciduous tooth loss.

RESULTS

The individual exhibited a mosaic of skeletal and dental pathological changes, including premature loss of deciduous dentition, premature eruption of permanent teeth generalised bone loss in both the mandible and maxilla; osteomyelitis of the left radius; osteolytic lesion on the body of the second lumbar vertebra, and marked expansions of the rib shafts due to sub-periosteal new bone formation.

CONCLUSION

A differential diagnosis considered indicates that the pathological changes of the individual were most likely associated with a comorbidity involving hypophosphatasia and tuberculosis.

SIGNIFICANCE

We present in this study several oral signs that could alert paleopathologists and bioarcheologists to systematically consider the potential of a condition that is rarely encountered in archaeological contexts.

LIMITATIONS

Due to poor preservation, this study was confined to the analysis of a partial maxilla and mandible, a left radius shaft and the axial skeleton (rib heads and vertebrae) of the individual.

SUGGESTIONS FOR FURTHER RESEARCH

Further radiographic, histological and genetic analyses would confirm the diagnosis.

TRPA1 up-regulation mediates oxidative stress in a pulpitis model in vitro

BACKGROUND AND PURPOSE

Pulpitis is associated with tooth hypersensitivity and results in pulpal damage. Thermosensitive transient receptor potential (TRP) ion channels expressed in the dental pulp may be key transducers of inflammation and nociception. We aimed at investigating the expression and role of thermo-TRPs in primary human dental pulp cells (hDPCs) in normal and inflammatory conditions.

EXPERIMENTAL APPROACH

Inflammatory conditions were induced in hDPC cultures by applying polyinosinic:polycytidylic acid (poly(I:C)). Gene expression and pro-inflammatory cytokine release were measured by RT-qPCR and ELISA. Functions of TRPA1 channels were investigated by monitoring changes in intracellular Ca2+ concentration. Mitochondrial superoxide production was measured using a fluorescent substrate. Cellular viability was assessed by measuring the activity of mitochondrial dehydrogenases and cytoplasmic esterases. TRPA1 activity was modified by agonists, antagonists, and gene silencing.

KEY RESULTS

Transcripts of TRPV1, TRPV2, TRPV4, TRPC5, and TRPA1 were highly expressed in control hDPCs, whereas TRPV3, TRPM2, and TRPM3 expressions were much lower, and TRPM8 was not detected. Poly(I:C) markedly up-regulated TRPA1 but not other thermo-TRPs. TRPA1 agonist-induced Ca2+ signals were highly potentiated in inflammatory conditions. Poly(I:C)-treated cells displayed increased Ca2+ responses to H2O2, which was abolished by TRPA1 antagonists. Inflammatory conditions induced oxidative stress, stimulated mitochondrial superoxide production, resulted in mitochondrial damage, and decreased cellular viability of hDPCs. This inflammatory cellular damage was partly prevented by the co-application of TRPA1 antagonist or TRPA1 silencing.

CONCLUSION AND IMPLICATIONS

Pharmacological blockade of TRPA1 channels may be a promising therapeutic approach to alleviate pulpitis and inflammation-associated pulpal damage.

Photodynamic therapy on mRNA levels in bacteria

Antimicrobial photodynamic therapy (aPDT) has shown efficacy in inactivating different bacterial species by photosensitizer-induced free radical production. Despite aPDT is considered unable to cause resistant strains, enzymatic pathways for detoxification of reactive oxygen species and transmembrane photosensitizer efflux systems could cause resistance to aPDT. Resistance mechanisms can be evaluated by measurement of mRNA from by quantitative reverse transcription polymerase chain reaction (RT-qPCR). Thus, the aim of this study was to access the mRNA level data obtained by RT-qPCR in bacterial cells submitted to photodynamic therapy. Studies performed on mRNA levels in bacteria after PDT were assessed on MEDLINE/Pubmed. The mRNA levels from genes related to various functions have been successfully evaluated in both Gram-positive and -negative bacteria after aPDT by RT-qPCR. Such an approach has improved the understanding of aPDT-induced effects, and reinforced the effectiveness of aPDT on bacteria, which can cause infections in different human tissues.

Investigation of the extent of post-extraction bone contraction and remodeling after 4 months. A prospective pilot study

OBJECTIVES

To investigate the correlation between the serum levels of 25(OH)D and the resorption of the alveolar bone walls and regeneration of the alveolar space after tooth extraction.

METHODS

14 adults in need of extraction of hopeless teeth were enrolled. An intraoral digital impression was performed, and each patient was tested to assess serum vitamin D levels. Subsequently, extraction of teeth and contextual guided bone regeneration was performed using porcine origin graft material and a resorbable collagen membrane to covert the defect. After 4 months, an impression was taken, and the model was scanned using a professional scanner for lab. At the same time, a cone beam computed tomography was performed to plan implant insertion through fully digital computer guided surgery. Bone was collected to perform histological and histomorphometric analysis. Pre and postoperative scans were compared using a specific software to estimate the volumetric changes. Tests were applied to investigate the relationship between the different predictor variables and the outcome variables.

RESULTS

14 patients were divided in 3 groups depending on the serum Vit-D levels, identifying three ranges corresponding to low (lower than 20), medium (between 20 and 30), and optimal vitamin D levels (higher than 30). Volumetric contraction after extraction was observed for all patients, without any significant difference between the groups. Focusing on the post-extraction regeneration, patients belonging to the group with lower levels of Vit-D displayed lower and more disorganized levels of bone. Immunohistochemistry analysis showed that Col1A1 and Osteocalcin had no physiological alteration. Osteopontin could be identified near the external surface of bone tissue granules. Runx2 signals were detected near the margins of bone trabeculae.

CONCLUSIONS

Serum vit-D levels do not appear to influence the extent of post-extraction bone contraction; on the contrary, they seem to influence the post-extraction regeneration.

CLINICAL SIGNIFICANCE

Vit D serum levels may influence the regenerative aspect during post-extraction turn-over. This might suggest controlling and (in case of low levels) recommend Vit D supplement in the patient diet in case of extraction.

Salivaomics in head and neck cancer

Salivaomics is a promising method for the early detection and monitoring of head and neck cancer (HNC). By analyzing salivary proteomics, RNA, and DNA, it identifies biomarkers that distinguish HNC patients from healthy individuals. Saliva's non-invasive, easily collectible nature and affordability make it an advantageous screening tool. Multiomics approaches, which explore genetic mutations, gene expression patterns, protein profiles, and metabolite levels, provide a comprehensive molecular perspective that enhances clinical applicability. The approaches enhance the precision of diagnoses, enable the development and application of targeted therapies, and contribute to the overall advancement of personalized medicine. Despite its potential, larger-scale studies are essential for validating biomarkers, and assessing sensitivity, accuracy, and specificity in detecting HNC. This review highlights salivaomics' potential as a non-invasive, accessible biological sample for early disease detection in HNC and underscores the value of multiomics in advancing this research. Salivaomics offers significant insights into the underlying mechanisms of HNC, enabling the discovery of robust, non-invasive biomarkers for improved disease management.

Maxillary Sinus Augmentation with Autogenous Tooth Grafting Material: A Systematic Review

The aim of this systematic review was to determine whether autogenous tooth grafting material (ATGM) is as safe and effective as other bone substitutes used for maxillary sinus augmentation procedures, evaluating histomorphometric and/or histological data, implant primary stability, associated complications and radiographic bone height measurements. An automated electronic search was conducted using four databases (Medline/PubMed, Scopus, Web of Science and Cochrane Library), supplemented by a manual search, to identify clinical human studies using particulate ATGM for the aforementioned procedure. The included studies had a sample size of at least four patients and were published before 31st July 2024. The Newcastle-Ottawa scale (NOS) and Joanna Briggs Institute (JBI) Critical Appraisal Checklist were used to assess the risk of bias in cohort studies and case series, respectively. Seven studies were included in the descriptive analysis, obtaining 128 participants (46.8% only treated with ATGM) and 192 placed implants. Due to the heterogeneity of the studies, meta-analysis could not be performed. The authors concluded that ATGM appears to be a feasible and safe alternative for maxillary sinus augmentation procedures. These results should be interpreted with caution due to the limited amount of scientific evidence on this topic and the heterogeneity between the included studies.

Enhanced functionality and migration of human gingival fibroblasts on vacuum ultraviolet light-treated titanium: An implication for mitigating cellular stress to improve peri-implant cellular reaction

PURPOSE

The maintenance of peri-implant health relies significantly on the integrity of the peri-implant seal, particularly vulnerable at the interface between implant abutment and soft tissue. Early healing stages around implants involve cellular exposure to oxidative stress. This study aimed to investigate whether vacuum ultraviolet (VUV)-treated titanium augments the growth and functionality of human gingival fibroblasts while mitigating cellular stress.

METHODS

Machined titanium plates underwent treatment with 172 nm VUV light for one minute, with untreated plates as controls. Human gingival fibroblasts were cultured on treated and untreated plates, and their behavior, growth, and functionality were assessed. Functionally impaired fibroblasts, treated with hydrogen peroxide, were also cultured on these titanium plates, and plate-to-plate transmigration ability was evaluated.

RESULTS

Fibroblasts on VUV-treated titanium exhibited a 50% reduction in intracellular reactive oxygen species production compared to controls. Additionally, glutathione, an antioxidant, remained undepleted in cells on VUV-treated titanium. Furthermore, the expression levels of inflammatory cytokines IL-1β and IL-8 decreased by 40-60% on VUV-treated titanium. Consequently, fibroblast attachment and proliferation doubled on VUV-treated titanium compared to those in the controls, leading to enhanced cell retention. Plate-to-plate transmigration assays demonstrated that fibroblasts migrated twice as far on VUV-treated surfaces compared to those in the controls. In particular, the transmigration ability, impaired in functionally impaired fibroblasts on the controls, was preserved on VUV-treated titanium.

CONCLUSIONS

VUV-treated titanium promotes the growth, function, and migration of human gingival fibroblasts by reducing cellular stress and enhancing antioxidative capacity. Notably, the transmigration ability significantly improved on VUV-treated titanium.

Role of circulating microparticles and cytokines in periodontitis associated with diabetes

Background

Periodontitis is a chronic inflammatory condition that affects the supporting tissues of the teeth, and can lead to serious complications such as tooth loss and systemic health problems, including diabetes, which have a bidirectional relationship with periodontitis. Circulating microparticles originate from different cell types after stimuli such as activation or apoptosis. Interleukins are related to processes in the regulation of the immune response, inflammation, and cell growth. This study aimed to evaluate circulating microparticles as well as interleukins in the plasma, at baseline and 1 month after the end of the non-surgical periodontal treatment.

Methods

Samples were collected from 45 patients, with moderate to severe periodontitis with diabetes (N = 25) and without diabetes (N = 20). Microparticles were evaluated in the platelet-poor plasma by flow cytometer. Cytokine levels were evaluated by the enzyme immunoabsorption assay (ELISA).

Results

Higher levels of the pro-inflammatory cytokines were found in the group with diabetes compared to the non-diabetic group both at baseline and 1 month after the end of the treatment. A higher IL-6/IL-10 ratio was found in patients with diabetes compared to the group without diabetes at T0 and T1, whereas an increased IFN-γ/IL-10 ratio was only found at T1 in patients with diabetes in comparison to the group without diabetes. In the group with diabetes, it was verified positive correlations between IL-10 and IL-6 or IFN-γ and a negative correlation between IL-6 and PMP, at T0; in contrast, in the T1, negative correlations were found between TNF-α and IL-10 or PMP. Besides, at T0, it was evidenced positive correlations both between circulating TNF-α and IL-6, and IL-10 and EMP, as well as a negative correlation between IL-10 and PMP in the group with diabetes. In addition, it was observed in T1 positive correlations between levels of TNF-α and IL-6, IFN-γ, or IL-10, and between PMP and IFN-γ, and between EMP and IL-6, TNF-α and IFN-γ in this group.

Conclusion

The results suggest a modulatory effect of the periodontitis associated with diabetes, as well as the periodontal treatment, in the systemic inflammatory status of the participants of the study.

Salivary gland organoid transplantation as a therapeutic option for radiation-induced xerostomia

BACKGROUND

Xerostomia is a pathological condition characterized by decreased salivation due to salivary gland dysfunction and is frequently attributed to irreversible damage as a side effect of radiation therapy. Stem cell-derived organoid therapy has garnered attention as a promising avenue for resolving this issue. However, Matrigel, a hydrogel commonly used in organoid culture, is considered inappropriate for clinical use due to its undefined composition and immunogenicity. In this study, we aimed to develop a method for culturing collagen-based human salivary gland organoids (hSGOs) suitable for clinical applications and evaluated their therapeutic effectiveness.

METHODS

Human salivary gland stem cells were isolated from the salivary gland tissues and cultured in both Matrigel and collagen. We compared the gene and protein expression patterns of salivary gland-specific markers and measured amylase activity in the two types of hSGOs. To evaluate the therapeutic effects, we performed xenogeneic and allogeneic transplantation using human and mouse salivary gland organoids (hSGOs and mSGOs), respectively, in a mouse model of radiation-induced xerostomia.

RESULTS

hSGOs cultured in Matrigel exhibited self-renewal capacity and differentiated into acinar and ductal cell lineages. In collagen, they maintained a comparable self-renewal ability and more closely replicated the characteristics of salivary gland tissue following differentiation. Upon xenotransplantation of collagen-based hSGOs, we observed engraftment, which was verified by detecting human-specific nucleoli and E-cadherin expression. The expression of mucins, especially MUC5B, within the transplanted hSGOs suggested a potential improvement in the salivary composition. Moreover, the allograft procedure using mSGOs led to increased salivation, validating the efficacy of our approach.

CONCLUSIONS

This study showed that collagen-based hSGOs can be used appropriately in clinical settings and demonstrated the effectiveness of an allograft procedure. Our research has laid the groundwork for the future application of collagen-based hSGOs in allogeneic clinical trials.

Cytokines in gingivitis and periodontitis: from pathogenesis to therapeutic targets

Chronic inflammatory processes in the oral mucosa and periodontitis are common disorders caused by microflora and microbial biofilms. These factors activate both the innate and adaptive immune systems, leading to the production of pro-inflammatory cytokines. Cytokines are known to play a crucial role in the pathogenesis of gingivitis and periodontitis and have been proposed as biomarkers for diagnosis and follow-up of these diseases. They can activate immune and stromal cells, leading to local inflammation and tissue damage. This damage can include destruction of the periodontal ligaments, gingiva, and alveolar bone. Studies have reported increased local levels of pro-inflammatory cytokines, such as interleukin-1beta (IL-1beta), tumor necrosis factor (TNF), IL-6, IL-17, and IL-23, in patients with periodontitis. In experimental models of periodontitis, TNF and the IL-23/IL-17 axis play a pivotal role in disease pathogenesis. Inactivation of these pro-inflammatory pathways through neutralizing antibodies, genetic engineering or IL-10 function has been demonstrated to reduce disease activity. This review discusses the role of cytokines in gingivitis and periodontitis, with particular emphasis on their role in mediating inflammation and tissue destruction. It also explores new therapeutic interventions that offer potential for research and clinical therapy in these chronic inflammatory diseases.

The Role of Deubiquitinating Enzymes in Primary Bone Cancer

Bone is a living, intricate, and dynamic tissue providing locomotion and protection of the body. It also performs hematopoiesis and mineral homeostasis. Osteosarcoma (OS), Ewing sarcoma (ES), and chondrosarcoma (CS) are primary bone cancers. OS and ES mostly develop in younger individuals, and CS generally develops in adults. Ubiquitination regulates numerous cellular processes. The deubiquitinating enzymes (DUBs) detach the ubiquitin molecules from the ubiquitin labeled substrate, altering ubiquitinated protein functions and regulating protein stability via various signaling pathways. Protein homeostasis and bone remodeling are both crucially influenced by the UPS. Recently, there have been several reports on DUBs involved in bone homeostasis and various bone disorders through the regulation of osteoblasts and osteoclasts via NF-κB, Wnt/β-catenin, TRAF6, TGFβ, ERK1/2, and PI3K/Akt pathways. However, DUBs regulating function in bone homeostasis is still in its infancy. Here, we summarized several recent identifications on DUBs, with a focus on their role in bone cancer progression. Therefore, the study attempts to summarize association with the expression level of DUBs as key factors driving bone cancers and also provide new insights on DUBs as key pharmacologic targets for bone cancer therapeutics.

A retrospective case series on bisphosphonate related osteonecrosis of the jaw in 20 cats

Introduction

This retrospective study highlights the salient aspects of a series of feline patients affected with bisphosphonate related osteonecrosis of the jaw. Though more commonly published in human literature, this presentation is rare in cats. The authors hope that this study will assist in making this a more globally known entity with subsequent improved prognosis.

Methods

Data was retrospectively obtained from the medical records between 2015 and 2021 of 20 cats with Medication Related Osteonecrosis of the Jaw. Data included patient information, clinical history, presenting complaint, systemic diseases, details referable to hypercalcemia and treatment thereof, bisphosphonate specifics (dose and duration), clinical presentation of the lesion, diagnostic testing including radiographic and histopathologic descriptions, treatment, and outcome.

Results

Pertinent results include that all 20 cats who developed Medication Related Osteonecrosis of the Jaw had been treated for idiopathic hypercalcemia with the bisphosphonate medication alendronate. Eighty-five percent of the cases had prior dental extractions at the site of MRONJ lesion. Ninety-five percent of the affected cats required a surgical procedure to control the disease. Thirty-five percent of cases required at least one revision surgery after the initial procedure was performed. Diagnosis of MRONJ was made by a correlation of diagnostic findings and patient history. No single diagnostic, or combination was pathognomonic for lesion diagnosis. As well, there were no statistically significant associations between patient variables assessed and the overall patient outcome.

Discussion

The case series reveals that cats with feline idiopathic hypercalcemia treated with alendronate may be at a risk for development of MRONJ, a serious oral condition with significant morbidity. Prior dental extraction sites in patients concurrently treated with bisphosphonate medications were often associated with MRONJ lesions. Therefore, any needed dental surgery should be performed prior to the use of bisphosphonates where possible. The authors have also included a relevant comparative literature review.

Propolis: a natural compound with potential as an adjuvant in cancer therapy - a review of signaling pathways

Propolis is a natural product used in cancer treatment, which is produced by bees via different sources. The chemical composition of Propolis is determined based on the climatic and geographical conditions, as well as harvesting time and method. This compound has been the subject of numerous investigational endeavors due to its expansive therapeutic capacity which includes antibacterial, anti-fungal, anti-inflammatory, anti-oxidant, anti-viral, and anti-cancer effects. The growing incidence rate of different cancers necessitates the need for developing novel preventive and therapeutic strategies. Chemotherapy, radiotherapy, and stem cell therapy have proved effective in cancer treatment, regardless of the adverse events associated with these modalities. Clinical application of natural compounds such as Propolis may confer promise as an adjuvant therapeutic intervention, particularly in certain subpopulations of patients that develop adverse events associated with anticancer regimens. The diverse biologically active compounds of propolis are believed to confer anti-cancer potential by modulation of critical signaling cascades such as caffeic acid phenethyl ester, Galangin, Artepillin C, Chrysin, Quercetin, Caffeic acid, Nymphaeols A and C, Frondoside A, Genistein, p-coumaric acid, and Propolin C. This review article aims to deliver a mechanistic account of anti-cancer effects of propolis and its components. Propolis can prevent angiogenesis by downregulating pathways involving Jun-N terminal kinase, ERK1/2, Akt and NF-ƘB, while counteracting metastatic progression of cancer by inhibiting Wtn2 and FAK, and MAPK and PI3K/AKT signaling pathways. Moreover, propolis or its main components show regulatory effects on cyclin D, CDK2/4/6, and their inhibitors. Additionally, propolis-induced up-regulation of p21 and p27 may result in cell cycle arrest at G2/M or G0/G1. The broad anti-apoptotic effects of propolis are mediated through upregulation of TRAIL, Bax, p53, and downregulation of the ERK1/2 signaling pathway. Considering the growing body of evidence regarding different anti-cancers effects of propolis and its active components, this natural compound could be considered an effective adjuvant therapy aimed at reducing related side effects associated with chemotherapy and radiotherapy.

Sleep bruxism (SB) may be not associated with obstructive sleep apnea (OSA): A comprehensive assessment employing a systematic review and meta-analysis

Associations between obstructive sleep apnea (OSA) and sleep bruxism (SB) are the subject of discussion but have not been confirmed definitively. Therefore, the objective of this meta-analysis was to examine the relationship between OSA and SB. This systematic review was conducted in accordance with PRISMA 2020 guidelines. PubMed, Embase and Web of Science were screened up to February 2024. The risk of bias was assessed with the Joanna Briggs Institute tool. 2260 records were identified, but only 14 studies were included. The odds of SB presence in OSA did not differ from the control group (OR: 1.23, 95 % CI: 0.47-3.20). The chance of SB compared to controls also did not differ in mild OSA (OR: 1.56, 95 % CI: 0.76-3.18), in moderate OSA (OR: 1.51, 95 % CI: 0.77-2.94) and in severe OSA (OR: 1.50, 95 % CI: 0.68-3.29). Additionally, the odds of SB were not increased in moderate OSA in comparison to mild OSA (OR: 1.14, 95 % CI: 0.63-2.94), in severe OSA compared to moderate OSA (OR: 1.31, 95 % CI: 0.61-2.79) or in severe OSA compared to mild OSA (OR = 1.42, 95 % CI: 0.69-2.93). The presence of SB in OSA did not differ between genders (OR: 2.14, 95 % CI: 0.65-7.05). The quality of the major studies included is low; therefore, the noted lack of correlation between OSA and SB may require further research. The relationship between OSA and SB seems to be multi-faceted. Presented results should not exempt clinicians from exact diagnosis of concomitant sleep conditions in OSA subjects.

Differentiation of Spiral Ganglion Neurons from Human Dental Pulp Stem Cells: A Further Step towards Autologous Auditory Nerve Recovery

The degeneration of spiral ganglion neurons (SGNs), which convey auditory signals from hair cells to the brain, can be a primary cause of sensorineural hearing loss (SNHL) or can occur secondary to hair cell loss. Emerging therapies for SNHL include the replacement of damaged SGNs using stem cell-derived otic neuronal progenitors (ONPs). However, the availability of renewable, accessible, and patient-matched sources of human stem cells is a prerequisite for successful replacement of the auditory nerve. In this study, we derived ONP and SGN-like cells by a reliable and reproducible stepwise guidance differentiation procedure of self-renewing human dental pulp stem cells (hDPSCs). This in vitro differentiation protocol relies on the modulation of BMP and TGFβ pathways using a free-floating 3D neurosphere method, followed by differentiation on a Geltrex-coated surface using two culture paradigms to modulate the major factors and pathways involved in early otic neurogenesis. Gene and protein expression analyses revealed efficient induction of a comprehensive panel of known ONP and SGN-like cell markers during the time course of hDPSCs differentiation. Atomic force microscopy revealed that hDPSC-derived SGN-like cells exhibit similar nanomechanical properties as their in vivo SGN counterparts. Furthermore, spiral ganglion neurons from newborn rats come in close contact with hDPSC-derived ONPs 5 days after co-culturing. Our data demonstrate the capability of hDPSCs to generate SGN-like neurons with specific lineage marker expression, bipolar morphology, and the nanomechanical characteristics of SGNs, suggesting that the neurons could be used for next-generation cochlear implants and/or inner ear cell-based strategies for SNHL.