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1.
Acta Biomater ; 2024 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-39299623

RESUMO

Peri-implantitis and osseointegration failure present considerable challenges to the prolonged stability of oral implants. To address these issues, there is an escalating demand for a resilient implant surface coating that seamlessly integrates antimicrobial features to combat bacteria-induced peri­implantitis, and osteogenic properties to promote bone formation. In the present study, a bio-inspired poly(amidoamine) dendrimer (DA-PAMAM-NH2) is synthesized by utilizing a mussel protein (DA) known for its strong adherence to various materials. Conjugating DA with PAMAM-NH2, inherently endowed with antibacterial and osteogenic properties, results in a robust and multifunctional coating. Robust adhesion between DA-PAMAM-NH2 and the titanium alloy surface is identified using confocal laser scanning microscopy (CLSM) and attenuated total reflectance-infrared (ATR-IR) spectroscopy. Following a four-week immersion of the coated titanium alloy surface in simulated body fluid (SBF), the antimicrobial activity and superior osteogenesis of the DA-PAMAM-NH2-coated surface remain stable. In contrast, the bifunctional effects of the PAMAM-NH2-coated surface diminish after the same immersion period. In vivo animal experiments validate the enduring antimicrobial and osteogenic properties of DA-PAMAM-NH2-coated titanium alloy implants, significantly enhancing the long-term stability of the implants. This innovative coating holds promise for addressing the multifaceted challenges associated with peri­implantitis and osseointegration failure in titanium-based implants. STATEMENT OF SIGNIFICANCE: Prolonged stability of oral implants remains a clinically-significant challenge. Peri-implantitis and osseointegration failure are two important contributors to the poor stability of oral implants. The present study developed a mussel-bioinspired poly(amidoamine) dendrimer (DA-PAMAM-NH2) for a resilient implant surface coating that seamlessly integrates antimicrobial features to combat bacteria-induced peri­implantitis, and osteogenic properties to promote bone formation to extend the longevity of oral implants.

4.
J Dent ; 148: 105214, 2024 09.
Artigo em Inglês | MEDLINE | ID: mdl-38950767

RESUMO

OBJECTIVES: To evaluate the mechanical properties of root canal dentin treated with sodium hypochlorite (NaOCl) in combination with hydroxyethylidene diphosphonic acid (HEDP) or ethylenediaminetetraacetic acid (EDTA). METHODS: For testing fracture resistance, 45 single-rooted teeth were instrumented and irrigated with NaOCl/HEDP, NaOCl/EDTA, or distilled water. Fifteen untreated teeth served as control. After obturation, specimens from the experimental groups were thermocycled, dynamically-loaded, and then statically-loaded in a universal testing machine until failure. For flexural strength analysis, 15 teeth were instrumented and irrigated with NaOCl/HEDP or NaOCl/EDTA. Root segments were sectioned into dentin bars and tested for flexural strength using a universal testing machine. For microhardness evaluation, 20 teeth were instrumented and irrigated with NaOCl/HEDP or NaOCl/EDTA. Dentin disks from the coronal-third of each root segment were prepared, one before and one after irrigation, for microhardness testing with a Knoop hardness tester. RESULTS: The highest fracture resistance was recorded in the untreated group, and the lowest in the EDTA group. Although the HEDP group had higher fracture resistance than the EDTA group, the distilled water group demonstrated even greater fracture resistance than the HEDP group. Specimens treated with HEDP had significantly higher flexural strength and microhardness values when compared with those treated with EDTA. CONCLUSION: The fracture resistance, flexural strength, and microhardness of root canal dentin were higher when root canals were irrigated with NaOCl/HEDP, when compared with NaOCl/EDTA. CLINICAL SIGNIFICANCE: Irrigating root canals with NaOCl combined with HEDP significantly improves the mechanical integrity of root canal dentin compared to the use of NaOCl with EDTA.


Assuntos
Quelantes , Dentina , Ácido Edético , Dureza , Teste de Materiais , Irrigantes do Canal Radicular , Hipoclorito de Sódio , Dentina/efeitos dos fármacos , Hipoclorito de Sódio/farmacologia , Humanos , Ácido Edético/farmacologia , Irrigantes do Canal Radicular/farmacologia , Quelantes/farmacologia , Estresse Mecânico , Ácido Etidrônico/farmacologia , Cavidade Pulpar/efeitos dos fármacos , Resistência à Flexão , Análise do Estresse Dentário , Preparo de Canal Radicular/métodos , Fraturas dos Dentes/prevenção & controle , Raiz Dentária/efeitos dos fármacos , Maleabilidade , Temperatura , Obturação do Canal Radicular/métodos
6.
NPJ Biofilms Microbiomes ; 10(1): 56, 2024 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-39003275

RESUMO

Dental calculus severely affects the oral health of humans and animal pets. Calculus deposition affects the gingival appearance and causes inflammation. Failure to remove dental calculus from the dentition results in oral diseases such as periodontitis. Apart from adversely affecting oral health, some systemic diseases are closely related to dental calculus deposition. Hence, identifying the mechanisms of dental calculus formation helps protect oral and systemic health. A plethora of biological and physicochemical factors contribute to the physiological equilibrium in the oral cavity. Bacteria are an important part of the equation. Calculus formation commences when the bacterial equilibrium is broken. Bacteria accumulate locally and form biofilms on the tooth surface. The bacteria promote increases in local calcium and phosphorus concentrations, which triggers biomineralization and the development of dental calculus. Current treatments only help to relieve the symptoms caused by calculus deposition. These symptoms are prone to relapse if calculus removal is not under control. There is a need for a treatment regime that combines short-term and long-term goals in addressing calculus formation. The present review introduces the mechanisms of dental calculus formation, influencing factors, and the relationship between dental calculus and several systemic diseases. This is followed by the presentation of a conceptual solution for improving existing treatment strategies and minimizing recurrence.


Assuntos
Biofilmes , Cálculos Dentários , Cálculos Dentários/microbiologia , Cálculos Dentários/prevenção & controle , Humanos , Animais , Biofilmes/crescimento & desenvolvimento , Bactérias/classificação , Saúde Bucal , Boca/microbiologia , Cálcio/metabolismo , Fósforo/metabolismo
8.
J Imaging Inform Med ; 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38806951

RESUMO

This study aimed to create a caries classification scheme based on cone-beam computed tomography (CBCT) and develop two deep learning models to improve caries classification accuracy. A total of 2713 axial slices were obtained from CBCT images of 204 carious teeth. Both classification models were trained and tested using the same pretrained classification networks on the dataset, including ResNet50_vd, MobileNetV3_large_ssld, and ResNet50_vd_ssld. The first model was used directly to classify the original images (direct classification model). The second model incorporated a presegmentation step for interpretation (interpretable classification model). Performance evaluation metrics including accuracy, precision, recall, and F1 score were calculated. The Local Interpretable Model-agnostic Explanations (LIME) method was employed to elucidate the decision-making process of the two models. In addition, a minimum distance between caries and pulp was introduced for determining the treatment strategies for type II carious teeth. The direct model that utilized the ResNet50_vd_ssld network achieved top accuracy, precision, recall, and F1 score of 0.700, 0.786, 0.606, and 0.616, respectively. Conversely, the interpretable model consistently yielded metrics surpassing 0.917, irrespective of the network employed. The LIME algorithm confirmed the interpretability of the classification models by identifying key image features for caries classification. Evaluation of treatment strategies for type II carious teeth revealed a significant negative correlation (p < 0.01) with the minimum distance. These results demonstrated that the CBCT-based caries classification scheme and the two classification models appeared to be acceptable tools for the diagnosis and categorization of dental caries.

9.
J Dent ; 146: 105020, 2024 07.
Artigo em Inglês | MEDLINE | ID: mdl-38670329

RESUMO

OBJECTIVE: To design and evaluate a matrix metalloproteinase 9 (MMP-9)-responsive hydrogel for vital pulp therapy. METHODS: A peptide linker with optimized sensitivity toward MMP-9 was crosslinked with 4-arm poly (ethylene glycol)-norbornene (PEG-NB) by thiol-norbornene photo-polymerization. This resulted in the formation of a hydrogel network in which the peptide IDR-1002 was incorporated. Hydrogel characterization and gelation kinetics were examined with Fourier-transform infrared spectroscopy, scanning electron microscopy, rheological testing, and swelling evaluation. Hydrogel degradation was examined through multiple exposure to pre-activated MMP-9, to simulate flare-ups of dental pulp inflammation. The IDR-1002 released from degraded hydrogels was measured with high-performance liquid chromatography. Effect of IDR-1002 released from hydrogels on one-week-old multispecies oral biofilms was evaluated using confocal laser scanning microscopy. RESULTS: MMP-9-responsive, injectable, and photo-crosslinkable hydrogels were successfully synthesized. When hydrogel degradation and release of IDR-1002 were examined with exposure to pre-activated MMP-9, IDR-1002 release was significantly correlated with elevated levels of MMP-9 (p < 0.05). The effectiveness of IDR-1002 in killing bacteria in multispecies oral biofilms was significantly enhanced when the hydrogels were immersed in 10 nM or 20 nM pre-activated MMP-9, compared to immersion in phosphate-buffered saline (p < 0.05). CONCLUSIONS: The MMP-9-responsive hydrogel is a promising candidate for on-demand delivery of bioactive agent in vital pulp therapy. CLINICAL SIGNIFICANCE: MMP-9 is one of the most important diagnostic and prognostic biomarkers for pulpitis. An MMP-9-responsive hydrogel has potential to be used as an in-situ on-demand release system for the diagnosis and treatment of dental pulp inflammation.


Assuntos
Hidrogéis , Metaloproteinase 9 da Matriz , Polietilenoglicóis , Metaloproteinase 9 da Matriz/metabolismo , Hidrogéis/química , Humanos , Polietilenoglicóis/química , Polpa Dentária/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Espectroscopia de Infravermelho com Transformada de Fourier , Peptídeos/química , Peptídeos/farmacologia , Microscopia Eletrônica de Varredura , Pulpite , Reologia , Microscopia Confocal , Reagentes de Ligações Cruzadas/química
11.
J Dent ; 144: 104923, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38461884

RESUMO

OBJECTIVES: This paper evaluated the success rates of pulpotomy, compared its efficacy with non-surgical root canal treatment (NSRCT), evaluated different pulpotomy techniques, and analyzed the effectiveness of contemporary bioactive materials in managing irreversible pulpitis in mature permanent teeth. DATA SOURCES: A comprehensive literature search was conducted across multiple databases including PubMed, Web of Science, Scopus, and the Cochrane Library. Search was conducted from the inception of each database to the present, adhering to PRISMA 2020 guidelines. STUDY SELECTION: Studies were selected through a multi-step screening process, focusing on adult populations, randomized controlled trials, and single-arm trials. DATA: Fifteen randomized controlled trials and eight single-arm trials were included. For a follow-up period of more than 24 months, pooled clinical success rate of pulpotomy was 92.9 % (95 %CI;82.1-99.0 %), whereas pooled radiographic success rate was 78.5 % (95 %CI;66.7-88.4 %). Meta-analyses showed that there was no significant difference in success rates between pulpotomy and NSRCT, between full and partial pulpotomy techniques, or between Mineral Trioxide Aggregate pulpotomy and Calcium Enriched Mixture pulpotomy. The results indicated comparable efficacy across these variables. CONCLUSIONS: The study highlights the potential of less invasive treatments. Pulpotomy may be a viable alternative to NSRCT for managing irreversible pulpitis in mature permanent teeth. Limitations such as the low quality of some single-arm trials and the high risk of bias in some randomized controlled trials highlight the need for further research to standardize methodologies and broaden literature inclusion for a more comprehensive understanding of the efficacy of pulpotomy, considering the high success rates reported. Clinical Significance This quantitative systematic review recognizes the potential of full or partial pulpotomy as a viable treatment alternative to root canal therapy for managing irreversible pulpitis in mature permanent teeth. Future studies should aim for standardized protocols to validate these findings and improve patient treatment outcomes.


Assuntos
Pulpite , Pulpotomia , Adulto , Humanos , Compostos de Alumínio/uso terapêutico , Compostos de Cálcio/uso terapêutico , Dentição Permanente , Combinação de Medicamentos , Pulpite/terapia , Pulpotomia/métodos , Ensaios Clínicos Controlados Aleatórios como Assunto , Materiais Restauradores do Canal Radicular/uso terapêutico , Tratamento do Canal Radicular/métodos , Silicatos/uso terapêutico , Resultado do Tratamento , Ensaios Clínicos Controlados como Assunto
12.
J Dent ; 143: 104882, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38331378

RESUMO

OBJECTIVES: This study investigated the relationship between bacterial growth, viability, and extracellular polymeric substances (EPS) formation in biofilms, particularly regarding resistance development. It also examined the impact of chemical factors on the EPS matrix and bacterial proliferation in oral biofilms. METHODS: Three multi-species oral biofilms were incubated in anaerobic conditions. Three strains of Enterococcus faecalis were incubated in aerobic conditions. The incubation periods ranged from 0 h to 7 days for short-term biofilms, and from 3 to 90 days for long-term biofilms. Fluorescent labeling with carboxyfluorescein diacetate succinimidyl ester (CFSE) and flow cytometry were used to track EPS and bacterial growth. Confocal laser scanning microscopy (CLSM) assessed bacterial viability and EPS structure. Biofilms aged 7, 14, and 21 days were treated with 2 % chlorhexidine (CHX) and 1 % sodium hypochlorite (NaOCl) to evaluate their effects on EPS and bacterial proliferation. RESULTS: Short-term biofilms showed rapid bacterial proliferation and a gradual increase in EPS, maintaining stable viability. In the first two weeks, a significant rise in CFSE indicated growing maturity. From 14 to 90 days, EPS and CFSE levels stabilized. Following treatment, CHX significantly reduced bacterial proliferation, while NaOCl decreased EPS volume. CONCLUSIONS: Biofilm development involves a balance between bacterial proliferation and EPS production. The complexity of this process poses challenges in treating biofilm-associated infections, requiring strategies tailored to the biofilm's developmental stage. CLINICAL SIGNIFICANCE: For effective root canal treatment, it is imperative to focus on reducing bacterial proliferation during the early stages of oral infections. In contrast, strategies aimed at minimizing EPS production could be more beneficial for long-term management of these conditions.


Assuntos
Biofilmes , Matriz Extracelular de Substâncias Poliméricas , Fluoresceínas , Succinimidas , Clorexidina/farmacologia , Hipoclorito de Sódio/farmacologia , Enterococcus faecalis , Microscopia Confocal , Proliferação de Células , Irrigantes do Canal Radicular/farmacologia
13.
Adv Healthc Mater ; 13(19): e2400318, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38408212

RESUMO

Drug-resistant bacterial infection of cutaneous wounds causes great harm to the human body. These infections are characterized by a microenvironment with recalcitrant bacterial infections, persistent oxidative stress, imbalance of immune regulation, and suboptimal angiogenesis. Treatment strategies available to date are incapable of handling the healing dynamics of infected wounds. A Schiff base and borate ester cross-linked hydrogel, based on phenylboronic acid-grafted chitosan (CS-PBA), dibenzaldehyde-grafted poly(ethylene glycol), and tannic acid (TA), is fabricated in the present study. Customized phenylboronic acid-modified zinc oxide nanoparticles (ZnO) are embedded in the hydrogel prior to gelation. The CPP@ZnO-P-TA hydrogel effectively eliminates methicillin-resistant Staphylococcus aureus (MRSA) due to the pH-responsive release of Zn2+ and TA. Killing is achieved via membrane damage, adenosine triphosphate reduction, leakage of intracellular components, and hydrolysis of bacterial o-nitrophenyl-ß-d-galactopyranoside. The CPP@ZnO-P-TA hydrogel is capable of scavenging reactive oxygen and nitrogen species, alleviating oxidative stress, and stimulating M2 polarization of macrophages. The released Zn2+ and TA also induce neovascularization via the PI3K/Akt pathway. The CPP@ZnO-P-TA hydrogel improves tissue regeneration in vivo by alleviating inflammatory responses, stimulating angiogenesis, and facilitating collagen deposition. These findings suggest that this versatile hydrogel possesses therapeutic potential for the treatment of MRSA-infected cutaneous wounds.


Assuntos
Quitosana , Hidrogéis , Staphylococcus aureus Resistente à Meticilina , Cicatrização , Quitosana/química , Quitosana/farmacologia , Cicatrização/efeitos dos fármacos , Animais , Hidrogéis/química , Hidrogéis/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Camundongos , Neovascularização Fisiológica/efeitos dos fármacos , Antioxidantes/farmacologia , Antioxidantes/química , Óxido de Zinco/química , Óxido de Zinco/farmacologia , Taninos/química , Taninos/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Células RAW 264.7 , Bases de Schiff/química , Bases de Schiff/farmacologia , Ácidos Borônicos/química , Ácidos Borônicos/farmacologia , Humanos , Masculino , Angiogênese
14.
Bone Res ; 12(1): 11, 2024 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-38383487

RESUMO

Brain-derived extracellular vesicles participate in interorgan communication after traumatic brain injury by transporting pathogens to initiate secondary injury. Inflammasome-related proteins encapsulated in brain-derived extracellular vesicles can cross the blood‒brain barrier to reach distal tissues. These proteins initiate inflammatory dysfunction, such as neurogenic heterotopic ossification. This recurrent condition is highly debilitating to patients because of its relatively unknown pathogenesis and the lack of effective prophylactic intervention strategies. Accordingly, a rat model of neurogenic heterotopic ossification induced by combined traumatic brain injury and achillotenotomy was developed to address these two issues. Histological examination of the injured tendon revealed the coexistence of ectopic calcification and fibroblast pyroptosis. The relationships among brain-derived extracellular vesicles, fibroblast pyroptosis and ectopic calcification were further investigated in vitro and in vivo. Intravenous injection of the pyroptosis inhibitor Ac-YVAD-cmk reversed the development of neurogenic heterotopic ossification in vivo. The present work highlights the role of brain-derived extracellular vesicles in the pathogenesis of neurogenic heterotopic ossification and offers a potential strategy for preventing neurogenic heterotopic ossification after traumatic brain injury. Brain-derived extracellular vesicles (BEVs) are released after traumatic brain injury. These BEVs contain pathogens and participate in interorgan communication to initiate secondary injury in distal tissues. After achillotenotomy, the phagocytosis of BEVs by fibroblasts induces pyroptosis, which is a highly inflammatory form of lytic programmed cell death, in the injured tendon. Fibroblast pyroptosis leads to an increase in calcium and phosphorus concentrations and creates a microenvironment that promotes osteogenesis. Intravenous injection of the pyroptosis inhibitor Ac-YVAD-cmk suppressed fibroblast pyroptosis and effectively prevented the onset of heterotopic ossification after neuronal injury. The use of a pyroptosis inhibitor represents a potential strategy for the treatment of neurogenic heterotopic ossification.


Assuntos
Lesões Encefálicas Traumáticas , Vesículas Extracelulares , Ossificação Heterotópica , Humanos , Ratos , Animais , Encéfalo/metabolismo , Ossificação Heterotópica/etiologia , Lesões Encefálicas Traumáticas/complicações , Barreira Hematoencefálica/metabolismo , Vesículas Extracelulares/metabolismo
15.
J Mech Behav Biomed Mater ; 152: 106407, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38277911

RESUMO

OBJECTIVE: To evaluate the effect of a Nisin-based dentin pretreatment solution on microtensile bond strength, antibacterial activity, and matrix metalloproteinase (MMP) activity of the adhesive interface. MATERIALS AND METHODS: 100 human molars were sectioned to expose dentin. The teeth were assigned to five groups (n = 20), according to the dentin pretreatment: 0.5%, 1.0%, or 1.5% Nisin; 0.12% chlorhexidine (positive control), and no solution (negative control), and divided into 2 subgroups: no aging, and thermomechanical aging. Specimens were etched with 37% H3PO4 for 15 s and submitted to the dentin pretreatment. Then, they were bonded with an adhesive (Adper Single Bond 2) and a resin composite for microtensile bond strength (µTBS) evaluation. Antibacterial activity against Streptococcus mutans was qualitatively examined using an agar diffusion test. Anti-MMP activity within hybrid layers was examined using in-situ zymography. Data were analyzed with two-factor ANOVA and post-hoc Tukey's test (α = 0.050). RESULTS: For µTBS, significant differences were identified for the factors "solutions" (p = 0.002), "aging" (p = 0.017), and interaction of the two factors (p = 0.002). In the absence of aging, higher µTBS was observed for the group 0.5% Nisin. In the presence of aging, all groups showed similar µTBS values. All Nisin concentrations were effective in inhibiting the growth of S. mutans. Endogenous MMP activity was more significantly inhibited using 0.5% and 1.0% Nisin (p < 0.050). CONCLUSION: 0.5% and 1.0% Nisin solutions do not adversely affect resin-dentin bond strength and exhibit a potential bactericidal effect against S. mutans. Both concentrations effectively reduce endogenous gelatinolytic activity within the hybrid layer. CLINICAL RELEVANCE: The use of 0.5% and 1.0% Nisin solutions for dentin pretreatment potentially contributes to preserving the adhesive interface, increasing the longevity of composite restorations.


Assuntos
Colagem Dentária , Nisina , Humanos , Nisina/farmacologia , Nisina/análise , Adesivos/análise , Dentina/química , Antibacterianos/farmacologia , Resinas Compostas/química , Resistência à Tração , Adesivos Dentinários/química , Cimentos de Resina/análise , Teste de Materiais
16.
Adv Mater ; 36(16): e2311659, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38175183

RESUMO

Enamel repair is crucial for restoring tooth function and halting dental caries. However, contemporary research often overlooks the retention of organic residues within the repair layer, which hinders the growth of dense crystals and compromises the properties of the repaired enamel. During the maturation of natural enamel, the organic matrix undergoes enzymatic processing to facilitate further crystal growth, resulting in a highly mineralized tissue. Inspired by this process, a biomimetic self-maturation mineralization system is developed, comprising ribonucleic acid-stabilized amorphous calcium phosphate (RNA-ACP) and ribonuclease (RNase). The RNA-ACP induces initial mineralization in the form of epitaxial crystal growth, while the RNase present in saliva automatically triggers a biomimetic self-maturation process. The mechanistic study further indicates that RNA degradation prompts conformational rearrangement of the RNA-ACP, effectively excluding the organic matter introduced earlier. This exclusion process promotes lateral crystal growth, resulting in the generation of denser enamel-like apatite crystals that are devoid of organic residues. This strategy of eliminating organic residues from enamel crystals enhances the mechanical and physiochemical properties of the repaired enamel. The present study introduces a conceptual biomimetic mineralization strategy for effective enamel repair in clinical practice and offers potential insights into the mechanisms of biomineral formation.


Assuntos
Biomimética , Fosfatos de Cálcio , Cárie Dentária , Humanos , RNA , Ribonucleases , Esmalte Dentário
17.
Bioact Mater ; 34: 37-50, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38173842

RESUMO

Calcification of cartilage by hydroxyapatite is a hallmark of osteoarthritis and its deposition strongly correlates with the severity of osteoarthritis. However, no effective strategies are available to date on the prevention of hydroxyapatite deposition within the osteoarthritic cartilage and its role in the pathogenesis of this degenerative condition is still controversial. Therefore, the present work aims at uncovering the pathogenic mechanism of intra-cartilaginous hydroxyapatite in osteoarthritis and developing feasible strategies to counter its detrimental effects. With the use of in vitro and in vivo models of osteoarthritis, hydroxyapatite crystallites deposited in the cartilage are found to be phagocytized by resident chondrocytes and processed by the lysosomes of those cells. This results in lysosomal membrane permeabilization (LMP) and release of cathepsin B (CTSB) into the cytosol. The cytosolic CTSB, in turn, activates NOD-like receptor protein-3 (NLRP3) inflammasomes and subsequently instigates chondrocyte pyroptosis. Inhibition of LMP and CTSB in vivo are effective in managing the progression of osteoarthritis. The present work provides a conceptual therapeutic solution for the prevention of osteoarthritis via alleviation of lysosomal destabilization.

18.
Dent Mater ; 40(2): 327-339, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38065798

RESUMO

OBJECTIVES: Extrafibrillar demineralization is an etching technique that removes only minerals from around the collagen fibrils for resin infiltration. The intrafibrillar minerals are left intact to avoid their replacement by water that is hard for adhesive resin monomers to displace. The present work reported the synthesis of a water-soluble methacryloyloxy glycol chitosan-EDTA conjugate (GCE-MA) and evaluated its potential as an extrafibrillar demineralization agent for self-etch dentin bonding. METHODS: Glycol chitosan-EDTA was functionalized with a methacryloyloxy functionality. Conjugation was confirmed using Fourier transform-infrared spectroscopy. The GCE-MA was used to prepare experimental self-etch primers. Extrafibrillar demineralization of the primers was evaluated with scaning electron microscopy and transmission electron microscopy. The feasibility of this new self-etch bonding approach was evaluated using microtensile bond strength testing and inhibition of dentin gelatinolytic activity. The antibacterial activity and cytotoxicity of GCE-MA were also analyzed. RESULTS: Conjugation of EDTA and the methacryloyloxy functionality to glycol chitosan was successful. The functionalized conjugate was capable of extrafibrillar demineralization of mineralized collagen fibrils. Tensile bond strength of the experimental self-etch primer to dentin was comparable to that of phosphoric acid-etched dentin and the commercial self-etch primer Clearfil SE Bond 2. The GCE-MA also inhibited soluble rhMMP-9. In-situ zymography detected minimal fluorescence in hybrid layers conditioned with the experimental primer. The GCE-MA was noncytotoxic and possessed antibacterial activities against planktonic bacteria. SIGNIFICANCE: Synthesis of GCE-MA brought into fruition a self-etch conditioner that selectively demineralizes the extrafibrillar mineral component of dentin. A self-etch primer prepared with GCE-MA achieved bond strengths comparable to commercial reference adhesive systems.


Assuntos
Quitosana , Colagem Dentária , Ácido Edético/análogos & derivados , Desmineralização do Dente , Humanos , Ácido Edético/química , Cimentos Dentários , Colágeno/química , Antibacterianos , Dentina/química , Minerais , Água , Adesivos Dentinários/farmacologia , Adesivos Dentinários/química , Resistência à Tração , Cimentos de Resina/química , Teste de Materiais
20.
Braz Dent J ; 34(4): 34-43, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37909640

RESUMO

This study evaluated the effect of heating on the physicochemical properties and surface changes of tricalcium silicate sealers. Three tricalcium silicate root canal sealers (Bio-C Sealer, BioRoot-RCS, EndoSequence BC Sealer), and one epoxy resin-based sealer (AH Plus; control) were tested. The effect of heating on setting time (ST) and flowability were assessed according to ANSI/ADA 57 and ISO 6876 standards. Solubility and dimensional change (DC) of the set sealers were evaluated at 24 hours and after 30 days; the pH of the water used in the DC testing was also measured. Tests were repeated with heated sealers in an oven at 100 °C for 1 min. SEM and EDS analysis were performed. Data were analyzed using One-Way ANOVA and Tukey post-hoc tests (α=5%). Heating decreased the ST for AH Plus and EndoSequence (p<0.05). Heating reduced flowability (p<0.05) and increased pH for AH Plus (p<0.05). The solubility of Bio-C (dried specimens) was not in accordance with the ANSI/ADA standard. The solubility of EndoSequence was significantly higher (p<0.05) when it was heated and dried after 30 days. DC of Bio-C (24 h and 30 days), BioRoot-RCS (30 days) and AH Plus (24 h and 30 days) were not in accordance with the standards. SEM and EDS analysis showed significant changes in sealer microstructure after heating. In conclusion, heating decreased the ST and increased the solubility of EndoSequence BC sealer. No significant changes in flowability, DC, and pH were identified for all three tricalcium silicate sealers after heat application. However, all sealers had significant surface changes.


Assuntos
Materiais Restauradores do Canal Radicular , Materiais Restauradores do Canal Radicular/química , Calefação , Cavidade Pulpar , Compostos de Cálcio/química , Resinas Epóxi/química , Silicatos/química , Teste de Materiais
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