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Journal of the Mechanical Behavior of... May 2024To evaluate whether coating enamel with a polymeric primer (PPol) containing titanium tetrafluoride (TiF) before applying a bleaching gel with 35% HO (35% BG) increases...
OBJECTIVE
To evaluate whether coating enamel with a polymeric primer (PPol) containing titanium tetrafluoride (TiF) before applying a bleaching gel with 35% HO (35% BG) increases esthetic efficacy, prevents changes in morphology and hardness of enamel, as well as reduces the cytotoxicity from conventional in-office bleaching.
MATERIALS AND METHODS
Standardized enamel/dentin discs were stained and bleached for 45 min (one session) with 35% BG. Groups 2TiF, 6TiF, and 10TiF received the gel on the enamel previously coated with PPol containing 2 mg/mL, 6 mg/mL, or 10 mg/mL, respectively. No treatment or application of 35% BG directly on enamel were used as negative control (NC), and positive control (PC), respectively. UV-reflectance spectrophotometry (CIE L*a*b* system, ΔE, and ΔWI, n = 8) determined the bleaching efficacy of treatments. Enamel microhardness (Knoop, n = 8), morphology, and composition (SEM/EDS, n = 4) were also evaluated. Enamel/dentin discs adapted to artificial pulp chambers (n = 8) were used for trans-amelodentinal cytotoxicity tests. Following the treatments, the extracts (culture medium + bleaching gel components diffused through the discs) were collected and applied to odontoblast-like MDPC-23 cells, which were assessed concerning their viability (alamarBlue, n = 8; Live/Dead, n = 4), oxidative stress (n = 8), and morphology (SEM). The amount of HO in the extracts was also determined (leuco crystal violet/peroxidase, n = 8). The numerical data underwent one-criterion variance analysis (one-way ANOVA), followed by Tukey's test, at a 5% significance level.
RESULTS
Regarding the ΔE, no difference was observed among groups 2TiF, 6TiF, and PC (p > 0.05). The ΔWI was similar between groups 2TiF and PC (p > 0.05). The ΔWI of group 6TiF was superior to PC (p < 0.05), and group 10TiF achieved the highest ΔE and ΔWI values (p < 0.05). Besides limiting enamel microstructural changes compared to PC, group 10TiF significantly increased the hardness of this mineralized dental tissue. The highest cellular viability occurred in 10TiF compared to the other bleached groups (p < 0.05). Trans-amelodentinal HO diffusion decreased in groups 2TiF, 6TiF, and 10TiF in comparison with PC (p < 0.05).
CONCLUSION
Coating enamel with a PPol containing TiF before applying a 35% BG may increase enamel microhardness and esthetic efficacy and reduce the trans-amelodentinal cytotoxicity of conventional in-office tooth bleaching. The PPol containing 10 mg/mL of TiF promoted the best outcomes.
Topics: Hydrogen Peroxide; Tooth Bleaching Agents; Dentin; Tooth Bleaching; Dental Enamel
PubMed: 38458078
DOI: 10.1016/j.jmbbm.2024.106497 -
ACS Biomaterials Science & Engineering Apr 2024Regenerating the pulp-dentin complex remains a decisive factor during apexification for immature permanent teeth. Peptide KN-17, which was modified based on the...
Regenerating the pulp-dentin complex remains a decisive factor during apexification for immature permanent teeth. Peptide KN-17, which was modified based on the structure of cecropin B, could effectively interfere with bacterial growth and induce the migration of human bone marrow stromal cells (hBMSCs). This study aimed to investigate the effect of KN-17 on the tissue regeneration. To our surprise, KN-17 can significantly stimulate angiogenesis in vitro and in vivo, which may provide a guarantee for apical closure. Herein, a novel peptide/KN-17 coassembled hydrogel is developed via a heating-cooling process. Npx-FFEY/KN-17 supramolecular hydrogel can induce vessel development, stimulate odontogenic differentiation of human dental pulp stem cells (hDPSCs), and exert an antibacterial effect on (). Furthermore, coronal pulp excised rat molars are supplied with KN-17 or KN-17-loaded hydrogel and transplanted subcutaneously in BALB/c-nu mice. After 4 weeks, the hydrogel Npx-FFEY/KN-17 stimulates the formation of multiple odontoblast-like cells and dentin-like structures. Our findings demonstrate that the KN-17-loaded hydrogel can promote the regeneration of the pulp-dentin complex for continued root development.
Topics: Mice; Rats; Humans; Animals; Hydrogels; Peptides; Mesenchymal Stem Cells; Odontoblasts; Dentin; Dental Pulp
PubMed: 38445444
DOI: 10.1021/acsbiomaterials.3c01376 -
Archives of Oral Biology May 2024To evaluate the role of induced nitric oxide synthase (iNOS) in nociception/orofacial discomfort in rats submitted to tooth whitening with hydrogen peroxide (H₂O₂).
OBJECTIVE
To evaluate the role of induced nitric oxide synthase (iNOS) in nociception/orofacial discomfort in rats submitted to tooth whitening with hydrogen peroxide (H₂O₂).
DESIGN
Wistar rats were divided into three groups (n = 24/group): a sham group not submitted to whitening treatment, a saline group submitted to whitening treatment, and a test group submitted to whitening treatment and blockade of iNOS with aminoguanidine 50 mg/kg/day. After 24 and 48 h, and 7 days, the animals were euthanized to collect trigeminal ganglia and maxillae to histomorphometric analysis (size of neuronal bodies and percentage of pulp area filled by vessels) and behavior/nociception (Grimace scales, scratching and biting counting, weight loss and nociception assay). ANOVA-1- or - 2-way tests were used (p < 0.05, GraphPadPrism 5.0).
RESULTS
The aminoguanidine-treated group showed a reduction in nociceptive threshold in the masseteric region (p < 0.001), Grimace scale scores (p < 0.001), number of scratching (p = 0.011) and body mass loss (p = 0.007). After 24 and 48 h of tooth bleaching, the saline group showed a significant increase in the mean area of the blood vessels (p = 0.020) and iNOS immunostaining in odontoblasts (p = 0.002) and non-odontoblasts cells (p = 0.025). Aminoguanidine reversed both increases. Tooth bleaching reduced the mean area of neuronal bodies, and aminoguanidine significantly reversed it (p = 0.019), but an increase in GFAP immunostaining in neuronal bodies did not reduce after seven-days or after aminoguanidine treatment (p = 0.003).
CONCLUSION
iNOS blockage by aminoguanidine plays an important role in nociception and orofacial discomfort by control of inflammation in dental pulp after tooth bleaching with hydrogen peroxide (H₂O₂) 35%.
Topics: Rats; Animals; Tooth Bleaching; Hydrogen Peroxide; Nociception; Nitric Oxide; Rats, Wistar; Nitric Oxide Synthase; Tooth Bleaching Agents; Guanidines
PubMed: 38442471
DOI: 10.1016/j.archoralbio.2024.105937 -
International Endodontic Journal Jun 2024This study aimed to investigate the anti-inflammatory and odontoblastic effects of cerium-containing mesoporous bioactive glass nanoparticles (Ce-MBGNs) on dental pulp...
AIMS
This study aimed to investigate the anti-inflammatory and odontoblastic effects of cerium-containing mesoporous bioactive glass nanoparticles (Ce-MBGNs) on dental pulp cells as novel pulp-capping agents.
METHODOLOGY
Ce-MBGNs were synthesized using a post-impregnation strategy based on the antioxidant properties of Ce ions and proposed the first use of Ce-MBGNs for pulp-capping application. The biocompatibility of Ce-MBGNs was analysed using the CCK-8 assay and apoptosis detection. Additionally, the reactive oxygen species (ROS) scavenging ability of Ce-MBGNs was measured using the 2,7-Dichlorofuorescin Diacetate (DCFH-DA) probe. The anti-inflammatory effect of Ce-MBGNs on THP-1 cells was further investigated using flow cytometry and quantitative real-time polymerase chain reaction (RT-qPCR). Moreover, the effect of Ce-MBGNs on the odontoblastic differentiation of the dental pulp cells (DPCs) was assessed by combined scratch assays, RT-qPCR, western blotting, immunocytochemistry, Alizarin Red S staining and tissue-nonspecific alkaline phosphatase staining. Analytically, the secretions of tumour necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were detected with enzyme-linked immunosorbent assay (ELISA).
RESULTS
Ce-MBGNs were confirmed to effectively scavenge ROS in THP-1-derived macrophages and DPCs. Flow cytometry and RT-qPCR assays revealed that Ce-MBGNs significantly inhibited the M1 polarization of macrophages (Mφ). Furthermore, the protein levels of TNF-α and IL-1β were downregulated in THP-1-derived macrophages after stimulation with Ce-MBGNs. With a step-forward virtue of promoting the odontoblastic differentiation of DPCs, we further confirmed that Ce-MBGNs could regulate the formation of a conductive immune microenvironment with respect to tissue repair in DPCs, which was mediated by macrophages.
CONCLUSIONS
Ce-MBGNs protected cells from self-produced oxidative damage and exhibited excellent immunomodulatory and odontoblastic differentiation effects on DPCs. As a pulp-capping agent, this novel biomaterial can exert anti-inflammatory effects and promote restorative dentine regeneration in clinical treatment. We believe that this study will stimulate further correlative research on the development of advanced pulp-capping agents.
Topics: Dental Pulp; Cerium; Humans; Anti-Inflammatory Agents; Nanoparticles; Reactive Oxygen Species; Tumor Necrosis Factor-alpha; Ceramics; Cell Differentiation; Glass; Odontoblasts; Regeneration; THP-1 Cells; Pulp Capping and Pulpectomy Agents; Interleukin-1beta; Apoptosis; Porosity; Cells, Cultured
PubMed: 38436622
DOI: 10.1111/iej.14055 -
The Saudi Dental Journal Feb 2024This study evaluated the influence of traumatic occlusion in the dentin-pulp complex a molar teeth submitted to subluxation.
BACKGROUND
This study evaluated the influence of traumatic occlusion in the dentin-pulp complex a molar teeth submitted to subluxation.
MATERIAL AND METHODS
Ninety Wistar rats were divided into groups Naïve (N), Subluxation (S) and Subluxation with traumatic occlusion (STO) and submitted to histological analysis after 7 and 21 days. A quantitative analysis was submitted to one-way ANOVA and Tukey's post-hoc test, and Chi-square and Bonferronís post-hoc test.
RESULTS
S and STO showed a significant increase in blood vessels area (p < 0.0005), amorphous fundamental substance (p < 0.0005) and reactionary dentin formation (p < 0.0005), as well as a decrease in the nuclear profile (p < 0.0005), odontoblast layer (p = 0.013 and p < 0.0005) by day 7 when compared with N. These changes normalized by day 21, except for the reactionary dentin (p < 0.0005) in both S and STO groups. Interestingly, the STO group exhibited significant changes in the increase of pulp calcification (p < 0.0005), presence of tubules with nuclei (p < 0.0005), and inflammatory infiltrate (p < 0.0005), as well reduction of nuclear profile (p < 0.0005), odontoblast layer (p < 0.0005) compared with N and S at day 21.
CONCLUSIONS
STO impaired the defence response and decreased pulp regeneration capacity by increasing the inflammatory infiltrate and pulp calcification, and decreasing the nucleated cell number in the odontoblast layer and central pulp.
PubMed: 38420008
DOI: 10.1016/j.sdentj.2023.11.012 -
Oral Diseases Feb 2024A zinc-finger transcription factor family comprising specificity proteins (SPs) and Krüppel-like factor proteins (KLFs) plays an important role in dentin development... (Review)
Review
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.
PubMed: 38409677
DOI: 10.1111/odi.14904 -
Journal of Molecular Histology Apr 2024Cytodifferentiation of odontogenic cells, a late stage event in odontogenesis is based on gene regulation. However, studies on the identification of the involved genes... (Review)
Review
Cytodifferentiation of odontogenic cells, a late stage event in odontogenesis is based on gene regulation. However, studies on the identification of the involved genes are scarce. The present study aimed to search for molecules for the cytodifferentiation of ameloblastic cells in rats. Differential display-PCR revealed a differentially expressed gene between cap/early bell stage and hard tissue formation stage in molars. This gene was identified as N-myc Downregulated Gene 1 (Ndrg1), which is the first report in tooth development. Real time PCR and western blotting confirmed that the mRNA level of Ndrg1 was higher during enamel formation than the cap stage. Ndrg1 expression was upregulated in the early bell, crown, and root stages in a time-dependent manner. These patterns of expression were similar in Ndrg2, but Ndrg3 and Ndrg4 levels did not change during the developmental stages. Immunofluorescence revealed that strong immunoreactivity against Ndrg1 were detected in differentiated ameloblasts only, not inner enamel epithelium, odontoblasts and ameloblastic cells in defected enamel regions. Alkaline phosphatase and alizarin red s stains along with real time PCR, revealed that Ndrg1 and Ndrg2 were involved in cytodifferentiation and enamel matrix mineralization by selectively regulating amelogenin and ameloblastin genes in SF2 ameloblastic cells. These results suggest that Ndrg may play a crucial functional role in the cytodifferentiation of ameloblasts for amelogenesis.
Topics: Animals; Rats; Ameloblasts; Amelogenesis; Molar; Muscle Proteins; Nerve Tissue Proteins; Odontogenesis; Proteins
PubMed: 38407765
DOI: 10.1007/s10735-024-10182-9 -
Journal of Dental Research Apr 2024Tooth development and regeneration are regulated through a complex signaling network. Previous studies have focused on the exploration of intracellular signaling... (Review)
Review
Tooth development and regeneration are regulated through a complex signaling network. Previous studies have focused on the exploration of intracellular signaling regulatory networks, but the regulatory roles of extracellular networks have only been revealed recently. Proteoglycans, which are essential components of the extracellular matrix (ECM) and pivotal signaling molecules, are extensively involved in the process of odontogenesis. Proteoglycans are composed of core proteins and covalently attached glycosaminoglycan chains (GAGs). The core proteins exhibit spatiotemporal expression patterns during odontogenesis and are pivotal for dental tissue formation and periodontium development. Knockout of core protein genes , , , and has been shown to result in structural defects in enamel and dentin mineralization. They are also closely involved in the development and homeostasis of periodontium by regulating signaling transduction. As the functional component of proteoglycans, GAGs are negatively charged unbranched polysaccharides that consist of repeating disaccharides with various sulfation groups; they provide binding sites for cytokines and growth factors in regulating various cellular processes. In mice, GAG deficiency in dental epithelium leads to the reinitiation of tooth germ development and the formation of supernumerary incisors. Furthermore, GAGs are critical for the differentiation of dental stem cells. Inhibition of GAGs assembly hinders the differentiation of ameloblasts and odontoblasts. In summary, core proteins and GAGs are expressed distinctly and exert different functions at various stages of odontogenesis. Given their unique contributions in odontogenesis, this review summarizes the roles of proteoglycans and GAGs throughout the process of odontogenesis to provide a comprehensive understanding of tooth development.
Topics: Mice; Animals; Glycosaminoglycans; Mice, Knockout; Odontogenesis; Extracellular Matrix Proteins; Tooth Germ
PubMed: 38407002
DOI: 10.1177/00220345231224228 -
Cells Feb 2024Regenerative endodontic procedures (REPs) are promising for dental pulp tissue regeneration; however, their application in permanent teeth remains challenging. We...
Regenerative endodontic procedures (REPs) are promising for dental pulp tissue regeneration; however, their application in permanent teeth remains challenging. We assessed the potential combination of an REP and local dental pulp cell (DPC) transplantation in the mature molars of C57BL/6 mice with (REP + DPC group) or without (REP group) transplantation of DPCs from green fluorescent protein (GFP) transgenic mice. After 4 weeks, the regenerated tissue was evaluated by micro-computed tomography and histological analyses to detect odontoblasts, vasculogenesis, and neurogenesis. DPCs were assessed for mesenchymal and pluripotency markers. Four weeks after the REP, the molars showed no signs of periapical lesions, and both the REP and REP + DPC groups exhibited a pulp-like tissue composed of a cellular matrix with vessels surrounded by an eosin-stained acellular matrix that resembled hard tissue. However, the REP + DPC group had a broader cellular matrix and uniquely contained odontoblast-like cells co-expressing GFP. Vasculogenesis and neurogenesis were detected in both groups, with the former being more prominent in the REP + DPC group. Overall, the REP was achieved in mature mouse molars and DPC transplantation improved the outcomes by inducing the formation of odontoblast-like cells and greater vasculogenesis.
Topics: Mice; Animals; Regenerative Endodontics; Dental Pulp; X-Ray Microtomography; Mice, Inbred C57BL; Dentin; Cell Transplantation
PubMed: 38391961
DOI: 10.3390/cells13040348 -
Journal of Developmental Biology Jan 2024Hyperplastic dental follicles (HDFs) represent odontogenic hamartomatous lesions originating from the pericoronal tissues and are often associated with impacted or...
Hyperplastic dental follicles (HDFs) represent odontogenic hamartomatous lesions originating from the pericoronal tissues and are often associated with impacted or embedded teeth. These lesions may occasionally feature unique calcifying bodies, known as calcifying whorled nodules (CWNs), characterized by stromal cells arranged in a whorled or spiral fashion. CWNs are typically observed in multiple calcifying hyperplastic dental follicles or regional odontodysplasia. In our study, we examined 40 cases of HDFs, including nine instances with characteristics of CWNs, referred to as calcifying hyperplastic dental follicles (CHDFs), which are infrequently accompanied by odontodysplasia. The median ages of the HDFs and CHDFs were 16 (ranging from 3 to 66) and 15 (ranging from 11 to 50) years, respectively. The lower third molars were the most frequently affected by HDSFs and CHDFs, followed by the upper canines. A histological examination was conducted on all 40 cases, with an immunohistochemical analysis performed on 21 of them. Among the cases with CWN, nine affected a single embedded tooth, with one exception. CWNs exhibited diverse calcifications featuring sparse or entirely deposited psammoma bodies, and some displayed dentinoid formation. Immunohistochemically, the stromal cells of HDFs were frequently positive for CD56 and nestin. By contrast, CWNs were negative for CD56 but positive for nestin as well as hairy and enhancer split 1 (HES1), with a few dentin sialoprotein (DSP)-positive calcified bodies. Our results revealed that hamartomatous CHDFs can impact multiple and single-embedded teeth. CWNs composed of nestin and HES1-positive ectomesenchymal cells demonstrated the potential to differentiate into odontoblasts and contribute to dentin matrix formation under the influence of HES1. This study is the first report documenting odontoblastic differentiation in HDFs. The rare occurrence of HDFs and CHDFs contributes to limited comprehension. To prevent misdiagnosis, a better understanding of these conditions is necessary.
PubMed: 38390958
DOI: 10.3390/jdb12010007