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1.
Int Endod J ; 54(1): 130-146, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32867001

RESUMO

AIM: To evaluate sources of student confidence and stress during the management of deep carious lesions and the exposed pulp during undergraduate clinics. Further aims were to identify barriers and facilitators, which could result in educational or practical improvements in the delivery of teaching and provision of treatment in this area. METHODOLOGY: A exploratory qualitative study design was used, based on recorded focus group interviews, guided by 12 predetermined questions. The discussions were transcribed verbatim and analysed by inductive qualitative content analysis. Common categories were identified to aid understanding. Forty undergraduate dental students from 4th and 5th years in Dublin Dental University Hospital participated in the study. RESULTS: Student stress and confidence were multifactorial and broadly linked to specific domains: clinical procedure, academic education, clinical training, evaluation/grading, organization and equipment, vital pulp biomaterial and the patient. Most students expressed a preference for one-stage selective carious removal to soft dentine rather than potential pulp exposure in deep carious lesions, noting that although it helped to decrease their immediate stress, it also caused longer-term concern by leaving caries close to the pulp. Nevertheless, their confidence was affected by limited clinical experience of carrying out selective removal procedures in deep caries. A recurrent finding was students citing high levels of stress after pulp exposure. Feelings including anger, fear, embarrassment and denial were associated with pulp exposure during deep caries management. Generally, the students felt able to manage pulp capping procedures, but were less certain about partial pulpotomy, suggesting that although they are aware of its advantages, they were unsure about the appropriate volume of pulp tissue to remove. To reduce stress, students suggested that laboratory teaching should employ new 3-D printed solutions and clinics should establish clear consensus amongst supervising teachers about the best way to manage the exposed pulp. CONCLUSIONS: Students lacked confidence as they neared the pulp and prefer selective caries removal techniques, which reduce the likelihood of pulp exposure. Students identified stressors and suggested improvements in several domains that would improve confidence. These ameliorations could lead to enhancements in student ability to perform these conservative techniques, and improve the provision of treatment in this area.


Assuntos
Cárie Dentária , Capeamento da Polpa Dentária , Cárie Dentária/terapia , Polpa Dentária , Exposição da Polpa Dentária , Medo , Humanos , Pulpotomia , Estudantes
2.
Int Endod J ; 54(1): 85-99, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32880979

RESUMO

As one of the most densely innervated tissues, the dental pulp contains abundant nerve fibres, including sensory, sympathetic and parasympathetic nerve fibres. Studies in animal models and human patients with pulpitis have revealed distinct alterations in protein expression and histological appearance in all types of dental nerve fibres. Various molecules secreted by neurons, such as classical neurotransmitters, neuropeptides and amino acids, not only contribute to the induction, sensitization and maintenance of tooth pain, but also regulate non-neuronal cells, including fibroblasts, odontoblasts, immune cells and vascular endothelial cells. Dental nerves are particularly important for the microcirculatory and immune responses in pulpitis via their release of a variety of functional substances. Further, nerve fibres are found to be involved in dental soft and hard tissue repair. Thus, understanding how dental nerves participate in pulpitis could have important clinical ramifications for endodontic treatment. In this review, the roles of dental nerves in regulating pulpal inflammatory processes are highlighted and their implications for future research on this topic are discussed.


Assuntos
Pulpite , Animais , Polpa Dentária , Células Endoteliais , Humanos , Microcirculação , Odontoblastos
3.
J Endod ; 47(1): 44-51, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33045261

RESUMO

The types of pulpal disease found in multirooted teeth may vary from one root canal to the next. Current endodontic treatment strategies allow for options such as regenerative endodontics, vital pulp therapy, or conventional root canal treatment depending on the disease status of the pulp in a specific root canal. A combination of procedures was used in the 3 teeth in this case series based on the assumed pulpal status in each canal. The follow-up ranged from 24-27 months, and in each case the healing response was satisfactory. This report illustrates the use of a combination of treatment procedures that can provide specific treatment benefits in various clinical situations.


Assuntos
Doenças da Polpa Dentária , Tratamento do Canal Radicular , Polpa Dentária , Necrose da Polpa Dentária/terapia , Humanos , Endodontia Regenerativa
4.
J Endod ; 47(1): 52-61, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33045266

RESUMO

INTRODUCTION: The transplantation of stem cells/tissue constructs into root canal space is a promising strategy for regenerating lost pulp tissue. However, the root canal system, which is cone shaped with a taper from the larger coronal end to the smaller apical end, limits the vascular supply and, therefore, the regenerative capacity. The current study aimed to fabricate built-in microchannels with different tapers to explore various approaches to endothelialize these microchannels. METHODS: The fluidic microchannels with varying tapers (parallel, 0.04, and 0.06) were fabricated within gelatin methacryloyl (GelMA) hydrogel (with or without stem cell from the apical papilla [SCAP] encapsulation) of different concentrations (5%, 7.5%, and 10% [w/v]). Green fluorescent protein-expressing human umbilical vein endothelial cells (HUVECs-GFP) were seeded alone or with SCAPs in coculture into these microchannels. Angiogenic sprouting was assessed by fluorescence and a confocal microscope and ImageJ software (National Institutes of Health, Bethesda, MD). Immunostaining was conducted to illustrate monolayer formation. Data were statistically analyzed by 1-way/2-way analysis of variance. RESULTS: HUVEC-only inoculation formed an endothelial monolayer inside the microchannel without angiogenic sprouting. HUVECs-GFP/SCAPs cocultured at a 1:1 ratio produced the longest sprouting compared with the other 3 ratios. The average length of the sprouting in the 0.04 taper microchannel was significantly longer compared with that in the parallel and 0.06 taper microchannels. Significant differences in HUVEC-GFP sprouting were observed in 5% GelMA hydrogel. Encapsulation of SCAPs within hydrogel further stimulated the sprouting of HUVECs. CONCLUSIONS: The coculture of SCAPs and HUVECs-GFP at a ratio of 1:1 in 0.04 taper fluidic microchannels fabricated with 5% (w/v) GelMA hydrogel with SCAPs encapsulated was found to be the optimal condition to enhance angiogenesis inside tapered microchannels.


Assuntos
Gelatina , Hidrogéis , Polpa Dentária , Células Endoteliais da Veia Umbilical Humana , Humanos , Neovascularização Fisiológica
5.
J Endod ; 47(1): 62-68, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33049226

RESUMO

INTRODUCTION: This study aimed to characterize the decellularization effects of different treatment protocols on the bovine dental pulp extracellular matrix (ECM) for tissue regeneration. METHODS: Seven different decellularization protocols consisting of trypsin/EDTA (for 1 hour, 24 hours, or 48 hours), sodium dodecyl sulfate (SDS, for 24 hours or 48 hours), Triton X-100 (for 1 hour), and deoxyribonuclease treatments were tested on bovine dental pulp tissue. The posttreatment samples were evaluated for remaining DNA and cellular contents, structural durability, immunofluorescence analysis, and in vivo immune responses. RESULTS: A complete decellularization process in all of the experimental groups was observed. The protocol that included 1 hour of Triton X-100 treatment and 12 hours of trypsin/EDTA treatment with no SDS treatment (P7 [12E-0S-1T]) showed the highest retention of glycosaminoglycan and the absence of nuclei in 4,6-diamidino-2-phenylindole. All groups showed significantly lower DNA content compared with native pulp tissue (P < .05), whereas compared with other protocols, protocols 1 (1 hour of EDTA/trypsin, 24 hours of SDS, and 1 hour of Triton X-100) and 4 (1 hour of EDTA/Trypsin, 48 hours of SDS, and no Triton X-100) resulted in the highest DNA contents (P < .05). Based on these results, P7 was further evaluated by immunofluorescence and in vivo immunogenicity. P7 specimens preserved collagen type I, whereas mononuclear cell infiltration along with neovascularization was observed in vivo. CONCLUSIONS: All tested treatments displayed the potential ability to decellularize pulp tissue and are viable options for a xenogeneic dental pulp ECM scaffold. The P7 (12E-0S-1T) protocol resulted in decellularized ECM with minimal organic matrix/ultrastructural detriments and an acceptable host immune response.


Assuntos
Polpa Dentária , Engenharia Tecidual , Animais , Bovinos , Matriz Extracelular , Octoxinol , Dodecilsulfato de Sódio , Tecidos Suporte
6.
Eur J Paediatr Dent ; 22(4): 331-333, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33337912

RESUMO

Dental pulp regeneration: An overview of the current approaches. Regenerative Endodontic Procedures (REPs) are biologically based procedures aimed at restoring the damaged structures and physiological functions of the pulp-dentine complex. Clinically, two strategies have been proposed so far to induce REP: cell transplantation and cell homing. REPs success relies primarily on the clinical and biological conditions of the tooth; therefore, cell homing strategies will not be consistently successful in every condition. Root canal treatment remains the standard of care for mature teeth with necrotic pulps and closed apex.


Assuntos
Polpa Dentária , Endodontia , Criança , Necrose da Polpa Dentária/terapia , Humanos , Regeneração , Tratamento do Canal Radicular
7.
PLoS One ; 15(11): e0242273, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33216762

RESUMO

Age is an important parameter to better understand wildlife populations, and is especially relevant for interpreting data for fecundity, health, and survival assessments. Estimating ages for marine mammals presents a particular challenge due to the environment they inhabit: accessibility is limited and, when temporarily restrained for assessment, the window of opportunity for data collection is relatively short. For wild dolphins, researchers have described a variety of age-determination techniques, but the gold-standard relies upon photo-identification to establish individual observational life histories from birth. However, there are few populations with such long-term data sets, therefore alternative techniques for age estimation are required for individual animals without a known birth period. While there are a variety of methods to estimate ages, each involves some combination of drawbacks, including a lack of precision across all ages, weeks-to-months of analysis time, logistical concerns for field applications, and/or novel techniques still in early development and validation. Here, we describe a non-invasive field technique to determine the age of small cetaceans using periapical dental radiography and subsequent measurement of pulp:tooth area ratios. The technique has been successfully applied for bottlenose dolphins briefly restrained during capture-release heath assessments in various locations in the Gulf of Mexico. Based on our comparisons of dental radiography data to life history ages, the pulp:tooth area ratio method can reliably provide same-day estimates for ages of dolphins up to about 10 years old.


Assuntos
Determinação da Idade pelos Dentes/métodos , Polpa Dentária/diagnóstico por imagem , Dente/diagnóstico por imagem , Determinação da Idade pelos Dentes/veterinária , Animais , Animais Selvagens , Golfinho Nariz-de-Garrafa , Polpa Dentária/fisiologia , Feminino , Masculino , Radiografia Dentária , Dente/fisiologia
8.
PLoS One ; 15(11): e0239526, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33147255

RESUMO

During the two World Wars, Bartonella quintana was responsible for trench fever and is now recognised as an agent of re-emerging infection. Many reports have indicated widespread B. quintana exposure since the 1990s. In order to evaluate its prevalence in ancient populations, we used real-time PCR to detect B. quintana DNA in 400 teeth collected from 145 individuals dating from the 1st to 19th centuries in nine archaeological sites, with the presence of negative controls. Fisher's exact test was used to compare the prevalence of B. quintana in civil and military populations. B. quintana DNA was confirmed in a total of 28/145 (19.3%) individuals, comprising 78 citizens and 67 soldiers, 20.1% and 17.9% of which were positive for B. quintana bacteraemia, respectively. This study analysed previous studies on these ancient samples and showed that the presence of B. quintana infection followed the course of time in human history; a total of 14/15 sites from five European countries had a positive prevalence. The positive rate in soldiers was higher than those of civilians, with 20% and 18.8%, respectively, in the 18th and 19th centuries, but the difference in frequency was not significant. These results confirmed the role of dental pulp in diagnosing B. quintana bacteraemia in ancient populations and showed the incidence of B. quintana in both civilians and soldiers.


Assuntos
Bacteriemia/diagnóstico , Bartonella quintana/genética , DNA Bacteriano/genética , Dente/microbiologia , Febre das Trincheiras/diagnóstico , Bacteriemia/microbiologia , Bartonella quintana/fisiologia , DNA Bacteriano/isolamento & purificação , Polpa Dentária/microbiologia , Europa (Continente)/epidemiologia , Fósseis/microbiologia , Humanos , Militares , Paleodontologia/métodos , Prevalência , Reação em Cadeia da Polimerase em Tempo Real , Análise de Sequência de DNA , Febre das Trincheiras/epidemiologia , Febre das Trincheiras/microbiologia
9.
J Biomed Nanotechnol ; 16(6): 965-974, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33187591

RESUMO

As an important recycling and degradation system, autophagy is considered to be critical in regulating stem cell differentiation. It has been shown that graphene oxide quantum dots (GOQDs) are a robust biological labelling tool for stem cells with little cytotoxicity. In this study, we explored the role of autophagy in regulating the impact of GOQDs on the odontoblastic differentiation of DPSCs during autophagy. Western blotting and immunofluorescence staining were used to evaluate the autophagic activity of DPSCs. Quantitative PCR, alizarin red S staining, and alkaline phosphatase staining were used to examine DPSC odontoblastic differentiation. The impacts of ROS scavengers on autophagy induction and reactive oxygen species (ROS) levels were also measured. Lentiviral vectors carrying Beclin1 siRNA sequences, as well as autophagy inhibitors (3-MA and bafilomycin A1), were used to inhibit autophagy. Initial exposure to GOQDs increased autophagic activity and enhanced DPSC mineralization. Autophagy inhibition suppressed GOQD-induced odontoblastic differentiation. Moreover, GOQD treatment induced autophagy in a ROS-dependent manner. GOQDs promoted differentiation, which could be modulated via ROS-induced autophagy.


Assuntos
Autofagia , Polpa Dentária , Pontos Quânticos , Espécies Reativas de Oxigênio , Células-Tronco , Diferenciação Celular , Células Cultivadas , Grafite , Odontoblastos
10.
J Oral Sci ; 63(1): 27-30, 2020 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-33012762

RESUMO

Minimal intervention is generally achieved by using direct composite resin (CR) restorations. However, deep caries lesions may lead to pulpal complications. This study evaluated the risk of endodontic complications after CR restoration in relation to depth of caries lesions. Data on 507 teeth from 316 adults treated with CR were analyzed. Caries depth was expressed as a percentage of the distance between the outer edge of the dental enamel and the pulp base on preoperative radiographs. The interval between CR restoration and follow-up root canal treatment was obtained from electronic treatment records for a period of 24 months. A Cox proportional hazards model was used to investigate the association between risk of endodontic complications and caries depth. Sixteen teeth (3.2%) required root canal treatment within 24 months. No root canal treatment was required after CR treatment for caries affecting <50% of the outer edge of enamel and pulp. As compared with CR treatment of caries lesions with a size of <80%, there was a significantly higher risk of root canal treatment for caries lesions with a size of 80% to 89% (hazard ratio, [95% CI]: 34.68 [4.23-284.11]) and ≥90% (92.01 [10.36-817.41], respectively).


Assuntos
Resinas Compostas , Cárie Dentária , Adulto , Cárie Dentária/terapia , Polpa Dentária , Restauração Dentária Permanente , Humanos , Tratamento do Canal Radicular
11.
Clin Oral Investig ; 24(12): 4185-4196, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33051813

RESUMO

OBJECTIVES: Complement is an efficient plasma immune surveillance system. It initiates inflammation by inducing vascular modifications and attracting immune cells expressing Complement receptors. Investigating Complement receptors in non-immune cells pointed out Complement implication in the regeneration of tissue such as liver, skin, or bone. This review will shed the light on Complement implication in the initial steps of dental tissue regeneration. MATERIALS AND METHODS: Review of literature was conducted on Complement local expression and implication in oral tissue regeneration in vivo and in vitro. RESULTS: Recent data reported expression of Complement receptors and soluble proteins in dental tissues. Cultured pulp fibroblasts secrete all Complement components. Complement C3b and MAC have been shown to control bacteria growth in the dental pulp while C3a and C5a are involved in the initial steps of pulp regeneration. Indeed, C3a induces pulp stem cell/fibroblast proliferation, and fibroblast recruitment, while C5a induces neurite growth, guides stem cell recruitment, and odontoblastic differentiation. Similarly, cultured periodontal ligament cells produce C5a which induces bone marrow mesenchymal stem cell recruitment. CONCLUSIONS: Overall, this review highlights that local Complement synthesis in dental tissues plays a major role, not only in eliminating bacteria but also in the initial steps of dental tissue regeneration, thus providing a link between dental tissue inflammation and regeneration. CLINICAL RELEVANCE: Complement provides an explanation for understanding why inflammation preceeds regeneration. This may also provide a biological rational for understanding the reported success conservative management of mature permanent teeth with carious pulp exposure.


Assuntos
Ativação do Complemento , Polpa Dentária , Diferenciação Celular , Fibroblastos , Humanos , Inflamação , Células-Tronco
12.
Genes Immun ; 21(5): 360-363, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33011745

RESUMO

Pulpitis, inflammation of the dental pulp, is a disease that often necessitates emergency dental care. While pulpitis is considered to be a microbial disease primarily caused by bacteria, viruses have also been implicated in its pathogenesis. Here, we determined the expression of the SARS-CoV2 receptor, angiotensin converting enzyme 2 (ACE2) and its associated cellular serine protease TPMRSS2 in the dental pulp under normal and inflamed conditions. Next, we explored the relationship between the SARS-CoV-2/human interactome and genes expressed in pulpitis. Using existing datasets we show that both ACE2 and TPMRSS2 are expressed in the dental pulp and, that their expression does not change under conditions of inflammation. Furthermore, Master Regulator Analysis of the SARS-CoV2/human interactome identified 75 relevant genes whose expression values are either up-regulated or down-regulated in both the human interactome and pulpitis. Our results suggest that the dental pulp is vulnerable to SARS-CoV2 infection and that SARS-CoV-2 infection of the dental pulp may contribute to worse outcomes of pulpitis.


Assuntos
Infecções por Coronavirus/complicações , Polpa Dentária/metabolismo , Pneumonia Viral/complicações , Pulpite/virologia , Betacoronavirus/metabolismo , Infecções por Coronavirus/metabolismo , Infecções por Coronavirus/virologia , Conjuntos de Dados como Assunto , Polpa Dentária/virologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Humanos , Pandemias , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/metabolismo , Pneumonia Viral/virologia , Pulpite/metabolismo , Receptores Virais/metabolismo , Serina Endopeptidases/metabolismo
13.
Int J Nanomedicine ; 15: 7775-7789, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33116500

RESUMO

Purpose: Several scaffolds and cell sources are being investigated for cartilage regeneration. The aim of the study was to prepare nanocellulose-based thermosensitive injectable hydrogel scaffolds and assess their potential as 3D scaffolds allowing the chondrogenic differentiation of embedded human dental pulp stem and progenitor cells (hDPSCs). Materials and Methods: The hydrogel-forming solutions were prepared by adding ß-glycerophosphate (GP) to chitosan (CS) at different ratios. Nanocellulose (NC) suspension was produced from hemp hurd then added dropwise to the CS/GP mixture. In vitro characterization of the prepared hydrogels involved optimizing gelation and degradation time, mass-swelling ratio, and rheological properties. The hydrogel with optimal characteristics, NC-CS/GP-21, was selected for further investigation including assessment of biocompatibility. The chondrogenesis ability of hDPSCs embedded in NC-CS/GP-21 hydrogel was investigated in vitro and compared to that of bone marrow-derived mesenchymal stem cells (BMSCs), then was confirmed in vivo in 12 adult Sprague Dawley rats. Results: The selected hydrogel showed stability in culture media, had a gelation time of 2.8 minutes, showed a highly porous microstructure by scanning electron microscope, and was morphologically intact in vivo for 14 days after injection. Histological and immunohistochemical analyses and real-time PCR confirmed the chondrogenesis ability of hDPSCs embedded in NC-CS/GP-21 hydrogel. Conclusion: Our results suggest that nanocellulose-chitosan thermosensitive hydrogel is a biocompatible, injectable, mechanically stable and slowly degradable scaffold. hDPSCs embedded in NC-CS/GP-21 hydrogel is a promising, minimally invasive, stem cell-based strategy for cartilage regeneration.


Assuntos
Cartilagem/fisiologia , Diferenciação Celular/efeitos dos fármacos , Condrogênese/efeitos dos fármacos , Polpa Dentária/citologia , Hidrogéis/farmacologia , Regeneração/efeitos dos fármacos , Células-Tronco/citologia , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Cartilagem/citologia , Cartilagem/efeitos dos fármacos , Celulose/química , Quitosana/química , Humanos , Hidrogéis/química , Porosidade , Ratos , Ratos Sprague-Dawley , Células-Tronco/efeitos dos fármacos , Tecidos Suporte/química
14.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 55(10): 710-715, 2020 Oct 09.
Artigo em Chinês | MEDLINE | ID: mdl-33045780

RESUMO

Accurate and measurable tooth preparation under the principle of protecting dental tissue, vital pulp and periodontal tissue health is a challenging procedure in esthetic dental restoration. The traditional protocol of tooth preparation often leads to complications after restoration because of the lack of precise preparation control. The pre-operative analysis and design, intraoperative guidance and sequence guidance technology of post-operative prosthesis production, with the target restoration space (TRS) as the core and digital technology as the support technology, embody the numerical requirements of the prosthesis space based on the actual measurement, and will lay the core foundation of the future digital prosthodontics. This paper introduces the new understanding of tooth preparation guidance, the classification and application of digital guides, the practice of micro tooth preparation guided by digital template, and summarizes the development direction of prosthodontics from experience guidance to digital guidance.


Assuntos
Estética Dentária , Preparo do Dente , Polpa Dentária , Periodonto , Prostodontia
15.
PLoS One ; 15(10): e0239672, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33002062

RESUMO

Human Fortilin, an antiapoptotic protein, has also been implicated in several diseases; however, several potential uses of fortilin have also been proposed. Bearing the implications of fortilin in mind, fortilin analog, which has no complication with diseases, is required. Since a recombinant full-length fortilin from Fenneropenaeus merguiensis (rFm-Fortilin (FL)) reported only 44% (3e-27) homologous to human fortilin, therefore the biological activities of the Fm-Fortilin (FL) and its fragments (F2, F12, and F23) were investigated for potential use against HEMA toxicity from filling cement to pulp cell. The rFm-Fortilin FL, F2, 12, and F23 were expressed and assayed for proliferation activity. The rFm-Fortilin (FL) showed proliferation activity on human dental pulp cells (HDPCs) and protected the cells from 2-hydroxy-ethyl methacrylate (HEMA) at 1-20 ng/ml. In contrast, none of the rFm-Fortilin fragments promoted HDPC growth that may be due to a lack of three conserved amino acid residues together for binding with the surface of Rab GTPase for proliferative activity. In addition, rFm-Fortilin (FL) activated mineralization and trend to suppressed production of proinflammatory cytokines, including histamine (at 10 ng/ml) and TNF-α (at 100 ng/ml). Besides, the rFm-Fortilin (FL) did not mutate the Chinese hamster ovary (CHO) cell. Therefore, the rFm-Fortilin (FL) has the potential use as a supplementary medical material to promote cell proliferation in patients suffering severe tooth decay and other conditions.


Assuntos
Proteínas de Artrópodes/farmacologia , Penaeidae/química , Animais , Proteínas de Artrópodes/genética , Proteínas de Artrópodes/isolamento & purificação , Células Cultivadas , Polpa Dentária/citologia , Polpa Dentária/efeitos dos fármacos , Histamina/metabolismo , Metacrilatos/toxicidade , Proteínas Recombinantes , Alinhamento de Sequência , Fator de Necrose Tumoral alfa/metabolismo
16.
J Contemp Dent Pract ; 21(6): 673-677, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33025937

RESUMO

AIM: Simulated pulpal pressure (PP) has been shown to affect the bond strength and nanoleakage of different adhesives at dentin interfaces but the effect of simulated PP on polymerization of adhesives has not been studied yet. Furthermore, it has been proposed that strong and mild self-etch adhesives have different polymerization behaviors. This study aimed to evaluate the effect of simulated PP on polymerization of two self-etch adhesives, Adper Prompt L-Pop (APLP) and Adper Easy Bond (AEB), by means of the Knoop hardness test. MATERIALS AND METHODS: Sixty caries-free human molars were used to prepare deep dentin specimens with a mean remaining dentin thickness of 0.9 mm. The specimens were bonded in the absence or presence of PP. The specimens were assigned to four equal groups (n = 15) as follows: AEB/-PP, APLP/-PP, AEB/+PP, and APLP/+PP. Bonding procedures were completed; then the specimens' hardness was measured with the Knoop test. Data were analyzed with two-way ANOVA and the t test. RESULTS: In the absence of PP, the hardness of AEB was significantly higher than that of APLP (p < 0.001). In contrast, when PP was simulated, the hardness of APLP was higher than that of AEB (p = 0.002). The hardness of AEB was not influenced by the presence of PP (p = 0.153). Simulation of PP resulted in a significant improvement in the hardness of APLP (p < 0.001). CONCLUSION: The polymerization degree of strong self-etch adhesive was lower compared to mild self-etch adhesive. In the presence of hydrostatic PP, the polymerization degree of strong self-etch adhesive was higher than mild self-etch adhesive. CLINICAL SIGNIFICANCE: Dentin moisture caused by positive PP might improve polymerization of strong self-etch adhesives.


Assuntos
Cimentos Dentários , Polpa Dentária , Dureza , Humanos , Dente Molar , Polimerização
17.
J Endod ; 46(9S): S56-S62, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32950196

RESUMO

INTRODUCTION: The maintenance of a stem cell pool is imperative to enable healing processes in the dental pulp tissue throughout life. As such, knowing mechanisms underlying stem cell self-renewal is critical to understand pulp pathophysiology and pulp regeneration. The purpose of this study was to evaluate the impact of stem cell factor (SCF) signaling through its receptor tyrosine kinase (c-Kit) on the self-renewal of human dental pulp stem cells (hDPSCs). METHODS: The hDPSCs were stably transduced with lentiviral vectors expressing shRNA-c-Kit or vector control. The impact of the SCF/c-Kit axis on hDPSC self-renewal was evaluated by using a pulpsphere assay in low attachment conditions and by evaluating the expression of polycomb complex protein Bmi-1 (master regulator of self-renewal) by Western blot and flow cytometry. RESULTS: The c-Kit-silenced hDPSCs formed fewer pulpspheres when compared with hDPSCs transduced with control vector (P < .05). Evaluation of pulpsphere morphology revealed the presence of 3 distinct sphere types, ie, holospheres, merospheres, and paraspheres. Although c-Kit silencing decreased the number of holospheres compared with control cells (P < .05), it had no effect on the number of merospheres and paraspheres. Recombinant human stem cell factor (rhSCF) increased the number of holospheres (P < .05) and induced dose-dependent Bmi-1 expression in hDPSCs. As expected, the inductive capacity of rhSCF on Bmi-1 expression and fraction of Bmi-1-positive cells was inhibited when we silenced c-Kit in hDPSCs. CONCLUSIONS: These results unveiled the role of SCF/c-Kit signaling on the self-renewal of hDPSCs and suggested that this pathway enables long-term maintenance of stem cell pools in human dental pulps.


Assuntos
Polpa Dentária , Células-Tronco , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Humanos , Transdução de Sinais
18.
Arch Oral Biol ; 119: 104881, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32911120

RESUMO

OBJECTIVES: The present study aimed firstly, to investigate whether pulpal circulatory changes elicited by innocuous tooth cooling and foot heating can be monitored with transmitted-light plethysmography (TLP), which detects pulpal blood volume changes, and secondly, to assess the effect of autonomic nervous control on TLP values. DESIGN: Thirty sound permanent maxillary incisors in 30 healthy volunteers (age: 25-35 years) were examined. The photodiode and 525-nm light-emitting diode of a prototype TLP system (J. Morita) were fixed onto the palatal and labial side, respectively, of each tooth with a custom-made acrylic cap. The subjects were stimulated for 10 min by cold (0 °C) water application to the experimental tooth or 30 min by foot heating with a footbath (43 °C). TLP and finger plethysmography were simultaneously recorded before (baseline), during and after stimulation. TLP values and autonomic nerve activity were statistically analyzed using a repeated measures one-way ANOVA followed by Tukey post-hoc test and partial correlation analysis. RESULTS: TLP values decreased significantly after both innocuous stimuli (P < 0.05), and returned to their baseline levels shortly after the removal of the stimuli. There was no significant serial correlation between the autonomic nervous activity and TLP values (P > 0.05). CONCLUSION: TLP was able to monitor the pulpal circulatory changes evoked by innocuous stimuli. Systemic autonomic nervous control mechanisms were not associated with the pulpal circulatory changes, suggesting the involvement of other mechanisms, such as somatosensory-sympathetic nervous control.


Assuntos
Polpa Dentária/irrigação sanguínea , Pletismografia , Fluxo Sanguíneo Regional , Adulto , Temperatura Baixa , , Temperatura Alta , Humanos , Incisivo
19.
Arch Oral Biol ; 119: 104896, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32932148

RESUMO

OBJECTIVES: This study investigates the post-extraction storage period of human dental pulp stem cells (hDPSCs) for stem cell banking by investigating the viability, function, mineralization, and gene expression of hDPSCs isolated from extracted teeth after 1 h, 6 h and 24 h post-tooth extraction. DESIGN: hDPSCs were extracted from the pulp of impacted third molar teeth after 1 h, 6 h, and 24 h after extraction. The mesenchymal stem cell (MSCs) properties of three groups of cells were analyzed using flow cytometry. Cell morphology and proliferation were analyzed using a light microscope and an MTT assay. The viability, function, mineralization, and gene expression of hDPSCs of 1 h, 6 h, and 24 h groups were also assessed. RESULTS: The delayed harvesting of hDPSCs for 1, 6 or 24 h caused a 31 % reduction in mineral nodule formation and a reduction in the gene expression of osteocalcin (OCN) and vascular endothelial growth factor-alpha (VEGFA). However, the 1, 6 or 24 h, time delay had little effect on MTT cell proliferation, cell viability or morphology. The delayed of harvesting of hDPSCs for 1, 6 or 24 h also had little effect on the expression of MSCs positive (CD44, CD106, CD90) or negative surface markers (CD45 and CD11b). CONCLUSIONS: Our results suggest that a 24 h delay in harvesting hDPSCs from extracted teeth can reduce their mineralization and gene activity but does not markedly reduce survival. Quicker hDPSCs harvesting is likely to yield more useful hDPSCs for experimentation and clinical treatment.


Assuntos
Polpa Dentária/citologia , Células-Tronco/citologia , Fatores de Tempo , Proliferação de Células , Sobrevivência Celular , Células Cultivadas , Humanos , Proteínas de Membrana/metabolismo , Osteocalcina/metabolismo , Extração Dentária , Fator A de Crescimento do Endotélio Vascular/metabolismo
20.
Arch Oral Biol ; 119: 104888, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32932150

RESUMO

OBJECTIVE: To compare proteomics and biological function of human dentin matrix molecules (hDMMs) and bovine dentin matrix molecules (bDMMs). DESIGN: Dentin powder from human or bovine teeth (n = 4) was demineralized in 10% (v/v) ethylenediaminetetraacetic acid for 7 days. The extracts were dialyzed, lyophilized and proteins were characterized using liquid chromatography-tandem mass spectrometry and shotgun proteomic analysis. To study biological function, mouse-derived undifferentiated dental pulp cells (OD21) were treated with 0.01, 0.1 or 1 µg/mL of hDMMs or bDMMs and proliferation was measured after 24 hours and 48 hours using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Cell migration was assessed after 24 hours using a Boyden chamber. Alizarin Red S staining was used to evaluate mineral formation. RESULTS: There were 307 proteins identified, of which 93 proteins were common to both species. Gene Ontology functional analysis demonstrated similar pattern of biological process in both species which consisted mainly of tissue development and biomineralization. hDMMs and bDMMs both enhanced cell proliferation. After 24 hours, all concentrations of bDMMs promoted cell proliferation (p ≤ 0.05), while hDMMs did not affect proliferation. After 48 hours, groups with 1µg/mL of bDMMs and 0.01µg/mL of hDMMs had increased cell proliferation compared to control (p ≤ 0.0001). All concentrations of hDMMs and bDMMs enhanced cell migration and mineralization (p ≤ 0.0001). CONCLUSION: bDMMs has similar biological functions as hDMMs. Moreover, bDMMs stimulated cell proliferation, migration and differentiation similar to hDMMs.


Assuntos
Polpa Dentária/citologia , Dentina/química , Regeneração , Animais , Bovinos , Diferenciação Celular , Movimento Celular , Proliferação de Células , Células Cultivadas , Feminino , Humanos , Camundongos , Proteômica
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