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1.
Molecules ; 26(5)2021 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-33652887

RESUMO

Although several natural plants and mixtures have been known and used over the centuries for their antibacterial activity, few have been thoroughly explored in the field of dentistry. Thus, the aim of this study was to enhance the antimicrobial activity of a conventional glass ionomer cement (GIC) with natural plant extracts. The effect of this alteration on the bond strength and film thickness of glass ionomer cement was evaluated and related to an 0.5% chlorohexidine modified GIC. Olive leaves (Olea europaea), Fig tree (Ficus carica), and the leaves and roots of Miswak (Salvadora persica) were used to prepare an alcoholic extract mixture. The prepared extract mixture after the evaporation of the solvent was used to modify a freeze-dried glass ionomer cement at three different extracts: water mass ratios 1:2, 1:1, and 2:1. An 0.5% chlorhexidine diacetate powder was added to a conventional GIC for the preparation of a positive control group (CHX-GIC) for comparison. The bond strength to dentine was assessed using a material-testing machine at a cross head speed of 0.5 mm/min. Failure mode was analyzed using a stereomicroscope at 12× magnification. The cement film thickness was evaluated in accordance with ISO standard 9917-1. The minimum number of samples in each group was n = 10. Statistical analysis was performed using a Kruskal-Wallis test followed by Dunn's post hoc test for pairwise comparison. There was a statistically insignificant difference between the median shear bond strength (p = 0.046) of the control group (M = 3.4 MPa), and each of the CHX-GIC (M = 1.7 MPa), and the three plant modified groups of 1:2, 1:1, 2:1 (M = 5.1, 3.2, and 4.3 MPa, respectively). The CHX-GIC group showed statistically significant lower median values compared to the three plant-modified groups. Mixed and cohesive failure modes were predominant among all the tested groups. All the tested groups (p < 0.001) met the ISO standard of having less than 25 µm film thickness, with the 2:1 group (M = 24 µm) being statistically the highest among all the other groups. The plant extracts did not alter either the shear bond strength or the film thickness of the GIC and thus might represent a promising additive to GICs.


Assuntos
Anti-Infecciosos/química , Cimentos Dentários/química , Cimentos de Ionômeros de Vidro/química , Extratos Vegetais/farmacologia , Anti-Infecciosos/farmacologia , Clorexidina/química , Clorexidina/farmacologia , Cimentos Dentários/farmacologia , Dentina/química , Dentina/microbiologia , Ficus/química , Cimentos de Ionômeros de Vidro/farmacologia , Humanos , Teste de Materiais , Olea/química , Extratos Vegetais/química , Folhas de Planta/química , Raízes de Plantas/química , Salvadoraceae/química , Resistência ao Cisalhamento , Propriedades de Superfície
2.
Life Sci ; 270: 119126, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33508295

RESUMO

AIMS: To investigate the biomimetic fabrication of fibrous-like organic-inorganic hybrid structures via a simple bottom-up approach, viz. self-assembly of simple molecules, and apply fibrous-like composites as a novel primer to improve dentin bond strengths of self-etch adhesives. MATERIALS AND METHODS: The resultants of commercial amorphous calcium phosphate (ACP) nanoparticles and 10-methacryloyloxydecyl dihydrogen phosphate (MDP) ethanol-aqueous solution were analyzed by TEM, SEM, XRD, DLS and AFM. The acid and alkali resistance of abovementioned self-assembled composites were analyzed with TEM. Micro-tensile bond strengths (MTBS) tests were performed after polished dentin surfaces were pretreated with self-assembled composites. The pretreated dentin surfaces and dentin-resin interfaces were characterized by SEM/TEM. KEY FINDINGS: ACP nanoparticles in MDP solution could self-assemble into fibrous-like nanotube structures in 8 nm diameter. Self-assembly and self-proliferation process went from ACP nanoparticles, dissolved ACP nanoparticles (less than 50 nm), twig-like structures and fibrous-like nanotubes to cellular networks. The fibrous-like nanotubes were only detected when the amount of ACP in reaction system were more than 0.01 g. The more ACP interacted with MDP, the more fibrous-like nanotubes were formed. After the dentin surfaces were treated with fibrous-like nanotube composites, MTBS could be significantly improved. Moreover, the fibrous-like nanotube structures could be resistant to acidic challenge, and were stable at least for 3 months. SIGNIFICANCE: The fibrous-like nanotube structures could be self-assembled via a bottom-up approach at certain ratio of MDP and commercial ACP nanoparticles. The application of fibrous-like nanotube composites as a novel primer prior to self-etch adhesives greatly improved dentin bond strengths.


Assuntos
Biomimética/métodos , Dentina/química , Nanotubos/química , Adesivos/química , Fosfatos de Cálcio/química , Humanos , Teste de Materiais/métodos , Metacrilatos/química , Nanopartículas/química , Resistência à Tração/fisiologia
3.
Nan Fang Yi Ke Da Xue Xue Bao ; 40(9): 1307-1312, 2020 Sep 30.
Artigo em Chinês | MEDLINE | ID: mdl-32990241

RESUMO

OBJECTIVE: To study the effect of nanohydroxyapatite (nHA) for promoting surface mineralization of demineralized dentin discs and adsorption of lead ions in simulated sewage water. METHODS: Sixty dentin disks were prepared from freshly extracted teeth with intact crown (including 30 premolars and 30 molars) and treated with 10% citric acid for 2 min to simulate dentinal tubules with dentin hypersensitivity. The etched dentin discs were brushed with distilled water, 0.2 g HA or 0.2 g nHA for 2 min twice a day for 7 consecutive days, after which scanning electron microscopy (SEM) was performed and calcium and phosphorus contents in the dentin discs were detected using EDS. Lead ion adsorption capacities of HA and nHA were tested by mixing 1 mL serial concentrations of HA and nHA suspensions with 50 mL lead ion solutions (1.0 mg/L). After 24 h, the residual lead ion concentration in the supernatant was measured using ICP to calculate lead ion adsorption rate and adsorption capacity of the materials. RESULTS: SEM showed a smooth surface and empty dentin tubules in the acid- etched dentin dics. The dentin dics treated with HA were covered with masses of particles that loosely attached to the surface, and the diameter of the dentin tubules was reduced. In nHA group, the dentin discs showed a fine and homogeneous surface clogging with a tight attachment, and the dentin tubule diameter was obviously reduced. Daily brushing with HA and nHA, especially the latter, significantly increased calcium and phosphorus contents on the surface of the dentin dics (P < 0.000). In lead ion adsorption experiment, the lead ion adsorption rate of HA decreased as its concentration increased with the highest adsorption rate of 83.01%; the adsorption rate of nHA increased with its concentration until the adsorption equilibrium was reached, and its highest adsorption rate was 98.79%. A good liner relationship was found between the adsorption ability and concentration of HA. CONCLUSIONS: Compared with HA, nHA has a better capacity for surface mineralization of acid-etched dentin discs and also a better ability of lead ion adsorption.


Assuntos
Dentina/química , Adsorção , Durapatita , Íons , Chumbo , Microscopia Eletrônica de Varredura
4.
PLoS One ; 15(8): e0237116, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32857787

RESUMO

Bone metastases are a frequent complication in prostate cancer, and several studies have shown that vitamin D deficiency promotes bone metastases. However, while many studies focus on vitamin D's role in cell metabolism, the effect of chronically low vitamin D levels on bone tissue, i.e. insufficient mineralization of the tissue, has largely been ignored. To investigate, whether poor tissue mineralization promotes cancer cell attachment, we used a fluorescence based adhesion assay and single cell force spectroscopy to quantify the adhesion of two prostate cancer cell lines to well-mineralized and demineralized dentin, serving as biomimetic bone model system. Adhesion rates of bone metastases-derived PC3 cells increased significantly on demineralized dentin. Additionally, on mineralized dentin, PC3 cells adhered mainly via membrane anchored surface receptors, while on demineralized dentin, they adhered via cytoskeleton-anchored transmembrane receptors, pointing to an interaction via exposed collagen fibrils. The adhesion rate of lymph node derived LNCaP cells on the other hand is significantly lower than that of PC3 and not predominately mediated by cytoskeleton-linked receptors. This indicates that poor tissue mineralization facilitates the adhesion of invasive cancer cells by the exposure of collagen and emphasizes the disease modifying effect of sufficient vitamin D for cancer patients.


Assuntos
Calcificação Fisiológica , Adesão Celular , Neoplasias da Próstata/metabolismo , Animais , Materiais Biomiméticos/química , Linhagem Celular Tumoral , Colágeno/metabolismo , Citoesqueleto/metabolismo , Dentina/química , Elefantes , Humanos , Masculino , Receptores de Superfície Celular/metabolismo , Tecidos Suporte/química , Vitamina D/metabolismo
5.
PLoS One ; 15(7): e0235080, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32639959

RESUMO

Detailed information about the lives and deaths of children in antiquity is often in short supply. Childhood dietary histories are, however, recorded and maintained in the teeth of both juveniles and adults. Primary tooth dentinal collagen does not turn over, preserving a sequential record of dietary changes. The use of nitrogen (δ15N) and carbon (δ13C) isotope values of incrementally sampled dentin are used in the study of breastfeeding practices but evidence for the addition of weaning foods, both in terms of mode and, particularly, duration, has remained analytically inaccessible to date. Here, we demonstrate how the novel use hydrogen isotope (δ2H) values of sequentially micro-sampled dentin collagen, measured from individuals excavated from a Punic cemetery, in Sardinia, Italy, can serve as a proxy for weaning food type and duration in ancient childhood diet. The weaning rate and age, based on the decline in δ15N and δ13C values of permanent first molars and the concomitant increase in δ2H, appears to be broadly similar among six individuals. Hydrogen isotopes vary systematically from a low value soon after birth, rising through early childhood. The early post-birth values can be explained by the influence of 2H-depleted lipids from mother's breastmilk and the later δ2H rise is consistent with, among other things, a substantial portion of boiled foodstuffs, such as the higher δ2H values observed in porridge. Overall δ2H in dentin shows great promise to elucidate infant and childhood feeding practices, and especially the introduction of supplementary foods during the weaning process.


Assuntos
Dieta/história , Aleitamento Materno/história , Pré-Escolar , Colágeno/análise , Dentina/química , Deutério/análise , Feminino , História Antiga , Humanos , Lactente , Itália , Desmame
6.
PLoS One ; 15(7): e0235283, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32614918

RESUMO

Recurrent caries, the development of carious lesions at the interface between the restorative material and the tooth structure, is highly prevalent and represents the primary cause for failure of dental restorations. Correspondingly, we exploited the self-assembly and strong antibiofilm activity of amphipathic antimicrobial peptides (AAMPs) to form novel coatings on dentin that aimed to prevent recurrent caries at susceptible cavosurface margins. AAMPs are alternative to traditional antimicrobial agents and antibiotics with the ability to target the complex and heterogeneous organization of microbial communities. Unlike approaches that have focused on using these AAMPs in aqueous solutions for a transient activity, here we assess the effects on microcosm biofilms of a long-acting AAMPs-based antibiofilm coating to protect the tooth-composite interface. Genomewise, we studied the impact of AAMPs coatings on the dental plaque microbial community. We found that non-native all D-amino acids AAMPs coatings induced a marked shift in the plaque community and selectively targeted three primary acidogenic colonizers, including the most common taxa around Class II composite restorations. Accordingly, we investigated the translational potential of our antibiofilm dentin using multiphoton pulsed near infra-red laser for deep bioimaging to assess the impact of AAMPs-coated dentin on plaque biofilms along dentin-composite interfaces. Multiphoton enabled us to record the antibiofilm potency of AAMPs-coated dentin on plaque biofilms throughout exaggeratedly failed interfaces. In conclusion, AAMPs-coatings on dentin showed selective and long-acting antibiofilm activity against three dominant acidogenic colonizers and potential to resist recurrent caries to promote and sustain the interfacial integrity of adhesive-based interfaces.


Assuntos
Anti-Infecciosos/administração & dosagem , Peptídeos Catiônicos Antimicrobianos/administração & dosagem , Biofilmes/efeitos dos fármacos , Placa Dentária/tratamento farmacológico , Anti-Infecciosos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Biofilmes/crescimento & desenvolvimento , Materiais Revestidos Biocompatíveis/química , Dentina/química , Dentina/microbiologia , Durapatita/química , Humanos , Proteínas Imobilizadas/administração & dosagem , Proteínas Imobilizadas/farmacologia , Microbiota/efeitos dos fármacos
7.
Sci Rep ; 10(1): 8127, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32415190

RESUMO

The present study aimed to evaluate the efficiency, effectiveness, and biocompatibility of two agents used for the chemomechanical removal of carious dentin. Sixty extracted carious human teeth were treated with a conventional bur (CBG) or chemomechanical agents - Papacarie Duo (PG) and Brix 3000 (BG). Treatment efficiency and effectiveness were assessed by the working time for carious dentin removal and Knoop microhardness values, respectively. Human pulp fibroblasts (FP6) were used to evaluate cytotoxicity by incorporating MTT dye, and genotoxicity was evaluated with the micronuclei test. The carious tissue was removed in a shorter time with CBG (median = 54.0 seconds) than the time required for chemomechanical agents (p = 0.0001). However, the time was shorter for Brix 3000 (BG) than that for Papacarie Duo (PG), showing mean values of 85.0 and 110.5 seconds, respectively. Regarding microhardness testing, all approaches tested were effective (p < 0.05). The final mean microhardness values were 48.54 ± 16.31 KHN, 43.23 ± 13.26 KHN, and 47.63 ± 22.40 KHN for PG, BG, and CBG, respectively. PG decreased cell viability compared to that of BG, but it presented no genotoxicity. Brix 3000 may be a good option for chemomechanical dentin caries removal due to its reduced removal time and lower cytotoxicity compared to the other treatment options.


Assuntos
Cárie Dentária/terapia , Preparo da Cavidade Dentária/métodos , Dentina/química , Fibroblastos/efeitos dos fármacos , Dureza/efeitos dos fármacos , Papaína/farmacologia , Hipoclorito de Sódio/farmacologia , Proliferação de Células , Células Cultivadas , Dentina/efeitos dos fármacos , Fibroblastos/patologia , Humanos , Técnicas In Vitro , Estresse Mecânico
8.
J Appl Oral Sci ; 28: e20190499, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32348441

RESUMO

Enzymatic degradation of the hybrid layer can be accelerated by the activation of dentin metalloproteinases (MMP) during the bonding procedure. MMP inhibitors may be used to contain this process. Objective To evaluate the degree of conversion (DC%), dentin bond strength (µTBS) (immediate and after 1 year of storage in water), and nanoleakage of an experimental (EXP) and a commercial (SB) adhesive system, containing different concentrations of the MMP inhibitor GM1489: 0, 1 µM, 5 µM and 10 µM. Methodology DC% was evaluated by FT-IR spectroscopy. Dentin bond strength was evaluated by µTBS test. Half of beams were submitted to the µTBS test after 24 h and the other half, after storage for 1 year. From each tooth and storage time, 2 beams were reserved for nanoleakage testing. Data were analyzed using ANOVA and Tukey's test to compare means (α=0.05). Results All adhesive systems maintained the µTBS after 1 year of storage. Groups with higher concentrations of inhibitor (5 µM and 10 µM) showed higher µTBS values than groups without inhibitor or with 1 µM. The nanoleakage values of all groups showed no increase after 1 year of storage and values were similar for SB and EXP groups, in both storage periods. The inhibitor did not affect the DC% of the EXP groups, but the SB5 and SB10 groups showed higher DC% values than those of SB0 and SB1. Conclusions The incorporation of GM1489 in the adhesive systems had no detrimental effect on DC%. The concentrations of 5 µM GM1489 for SB and 5 µM or 10 µM for EXP provided higher µTBS than groups without GM1489, in the evaluation after 1 year of storage; whereas the concentration of inhibitor did not affect adhesive systems nanoleakage.


Assuntos
Cimentos Dentários/química , Dentina/química , Inibidores de Metaloproteinases de Matriz/química , Metacrilatos/química , Polietilenoglicóis/química , Ácidos Polimetacrílicos/química , Análise de Variância , Colagem Dentária/métodos , Corrosão Dentária/métodos , Infiltração Dentária , Dentina/efeitos dos fármacos , Humanos , Teste de Materiais , Valores de Referência , Reprodutibilidade dos Testes , Espectroscopia de Infravermelho com Transformada de Fourier , Estatísticas não Paramétricas , Propriedades de Superfície , Resistência à Tração , Fatores de Tempo
9.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 55(2): 135-138, 2020 Feb 09.
Artigo em Chinês | MEDLINE | ID: mdl-32074678

RESUMO

Establishing a stable resin-dentin hybrid layer is an effective method to improve the adhesion durability of the restoration. The biomodification of dentin by cross-linkers can enhance the mechanical properties of collagen and resistance to enzymatic hydrolysis while, inhibiting the process of demineralization and promoting the remineralization of dentin, which has the potential clinical applicability of preventing dental caries and improving adhesive property. This review summarizes the biomodification of dentin type Ⅰ collagen by different cross-linkers.


Assuntos
Colágeno Tipo I/química , Colagem Dentária , Adesivos Dentinários , Dentina/química , Cárie Dentária/prevenção & controle , Humanos , Teste de Materiais , Cimentos de Resina
10.
Braz Oral Res ; 34: e001, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32022221

RESUMO

This study analyzed the effect of prior application of copaiba oil (CO) emulsions as a dentin cleaning substance on microleakage and microtensile adhesive strength. Twenty-five premolars and sixty-four molars were used for microleakage and microtensile assays. For the microleakage assays, specimens with standard class V cavities were divided (n = 5), according to the tested CO emulsions: CO10%X, CO10%Y, and CO10%Z, as well as chlorhexidine 2% (CHX) and distilled water (DW), as positive and negative controls, respectively. Restorations were performed using the Adper Single Bond® and/or Clearfil SE Bond® systems. Cervical, occlusal, distal and mesial sections were assessed for tracer penetration degree at the composite/tooth interface. For the microtensile assay, healthy molars were divided into sixteen groups, in which artificial caries were induced in half of the groups. Dentin surfaces were treated with CO10%X and CO10%Y, CHX and DW. Microtensile bond strength was measured by fixing each sample to the plate of a universal testing machine operated at a speed of 0.5 mm/minute until failure. Dentin treated with CO10%X showed a lower infiltration rate than dentin treated with the other CO emulsions, CHX2% and DW. According to the microtensile assay, both healthy and affected dentin treated with CO10%X and Adper Single Bond® adhesive system presented higher adhesive strength. CO emulsion, used as a dentin biomodifier, interfered positively in microleakage and improved adhesive strength after acid etching in the Adper Single Bond® adhesive system, or before applying the Clearfil SE Bond® self-etching system.


Assuntos
Colagem Dentária/métodos , Adesivos Dentinários/química , Dentina/efeitos dos fármacos , Fabaceae/química , Óleos Vegetais/química , Análise de Variância , Clorexidina/química , Resinas Compostas/química , Cimentos Dentários/química , Infiltração Dentária , Dentina/química , Emulsões/química , Humanos , Teste de Materiais , Reprodutibilidade dos Testes , Cimentos de Resina/química , Estatísticas não Paramétricas , Propriedades de Superfície , Resistência à Tração
11.
Microsc Res Tech ; 83(5): 514-522, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31912929

RESUMO

This study evaluated the shear bond strength (SBS) and internal marginal adaptation of pulp-capping materials to dentin. Flat occlusal deep dentin surfaces were produced and randomly assigned to two groups (sound or artificial caries-affected dentin). The specimens in each group were assigned to one of seven subgroups according to the materials used: Biodentine, Theracal LC, Ultra-Blend plus, Calcimol LC, ApaCal ART, EQUIA Forte, and Ionoseal. Buildups (3-mm inner diameter and 2-mm deep) were made over the dentin surfaces. The bonded specimens were tested under shear forces at a crosshead speed of 0.8 mm/min and fracture modes were determined using a stereomicroscope at 25× magnification. The materials were applied to the pulp floor of prepared Class I cavities and then the cavities were restored with composite resin. Restored molar teeth were subjected to 5,000 thermocycles and sectioned in a bucco-lingual direction. Resin replicas were made to determine the adaptation at the pulp floor with scanning electron microscopy. Significant differences were determined among both bond strengths and gap formations of the materials. EQUIA Forte applied to both dentin substrates had a significantly higher SBS than the other materials. The bond strength of each material was not influenced by the dentin condition. Biodentine (3.03%), EQUIA Forte (7.83%), and Theracal LC (13.37%) had lower gap formations compared to other materials but were not significantly different from each other.


Assuntos
Colagem Dentária , Capeamento da Polpa Dentária , Adesivos Dentinários/química , Dentina/química , Dentina/ultraestrutura , Polpa Dentária/ultraestrutura , Humanos , Técnicas In Vitro , Teste de Materiais , Microscopia Eletrônica de Varredura , Dente Molar
12.
Molecules ; 25(1)2020 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-31947753

RESUMO

The rat has been considered as an appropriate animal model for the study of the mineralization process in humans. In this work, we found that the phosphorus species in human dentin characterized by solid-state NMR spectroscopy consist mainly of orthophosphate and hydrogen phosphate. Some orthophosphates are found in a disordered phase, where the phosphate ions are hydrogen-bonded to structural water, some present a stoichiometric apatite structure, and some a hydroxyl-depleted apatite structure. The results of this study are largely the same as those previously obtained for rat dentin. However, the relative amounts of the various phosphorus species in human and rat dentin are dramatically different. In particular, stoichiometric apatite is more abundant in human dentin than in rat dentin, whereas the converse is true for disordered-phase orthophosphates. Furthermore, spatial proximity among all phosphorus species in human dentin is identical within experimental error, in contrast to what observed for rat dentin. Although it is not clear how these spectroscopic data could relate to the hierarchical structure or the mechanical properties of teeth, our data reveal that the molecular structures of human and rat dentin at different growth stages are not exactly the same.


Assuntos
Apatitas/química , Dentina/química , Espectroscopia de Ressonância Magnética , Fosfatos/análise , Fósforo/análise , Humanos
13.
Microsc Res Tech ; 83(4): 393-401, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31868286

RESUMO

This study evaluates the bond strength of four self-etching adhesive systems with different acidity levels in normal and artificially hypermineralized dentin substrate. Healthy human molars were divided into groups: normal dentin-N (n = 36) and artificially hypermineralized dentin-H (n = 36). Self-etching adhesive systems Clearfil S3 Bond (n = 9), Optibond All in One (n = 9), Clearfil SE Bond (n = 9), and Adhese (n = 9) were used for both the N and H groups. Transparent cylindrical matrices were positioned on the treated dentin surfaces, filled with composite resin, and light-cured for 40 s. After the transparent cylindrical matrices were removed, the specimens were stored for 24 hr in a humid environment at 37°C and were subjected to a micro-shear bond strength test. For each group, a specimen was prepared and evaluated in scanning electron microscope for adhesive interface observation. Normality was confirmed and the two-way analysis of variance and Games-Howell post-tests were conducted (α = .05). The data demonstrated an interaction between the adhesive system and type of dentin substrate (p < .01). For normal dentin, all adhesive systems assessed were adequate; however, in the hypermineralized dentin, the Clearfil SE Bond two-step self-etching adhesive system with mild pH presented the highest immediate bond strength. There was a predominance of adhesive failures for all adhesive systems in the different dentin substrates evaluated. It was concluded that the self-etching adhesive systems evaluated were efficient for both substrates, and for the hypermineralized dentin, the Clearfil SE Bond presented a higher bond strength value.


Assuntos
Ácidos , Adesivos Dentinários/farmacologia , Dentina/química , Teste de Materiais/métodos , Minerais/química , Dentina/efeitos dos fármacos , Humanos , Microscopia Eletrônica de Varredura , Dente Molar/efeitos dos fármacos , Resistência ao Cisalhamento , Estresse Mecânico , Resistência à Tração
14.
Microsc Res Tech ; 83(2): 186-195, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31701615

RESUMO

This study evaluated the effect of 10% sodium hypochlorite (NaOCl) as deproteinizing agent and storage media on bond strength (BS) of two etch-and-rinse adhesive systems to dentin. Twenty-eight sound extracted human third molars were divided in four groups (n = 7), according to dentin treatment (conventional etching or etching followed by 10% NaOCl application) and adhesive systems (GB-Gluma 2Bond and OS-One-Step). After dentin treatments and adhesive application, a composite block was built-up on dentin surface and teeth were serially sectioned to obtain bonded sticks specimens. The sticks were submitted to three aging conditions: (24H) 24 hr in water (immediate), (SH) 3 hr of NaOCl accelerated-aging or (1Y) 1 year of water storage. Afterward, submitted to microtensile bond strength test (µTBS), failure modes and adhesive interfaces analyzes. Data were analyzed by two-way analysis of variance (ANOVA) and Tukey's test (α = .05). Dentin deproteinization before bonding significantly reduced µTBS for GB-treated group (p < .05), regardless the aging conditions. Water storage for 1 year (1Y) and NaOCl accelerated-aging (SH) decreased µTBS for both adhesives. Yet, the groups stored in NaOCl (SH) exhibited the lowest BS results (p < .05). Bond strength of deproteinized dentin was dependent on the adhesive system composition and NaOCl accelerated-aging promoted decreased bond strength and further degradation than water storage for 1 year.


Assuntos
Adesivos/química , Dentina/química , Dente Serotino , Hipoclorito de Sódio/química , Colagem Dentária , Análise do Estresse Dentário , Humanos , Teste de Materiais , Resistência à Tração , Água
15.
Carbohydr Polym ; 229: 115547, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31826527

RESUMO

Chondroitin sulfate (CS) is widespread in mineralized tissues and is considered to play crucial roles during the mineralization process. However, its role in biomineralization remains controversial. In the present study, CS is immobilized to collagen fibrils to mimic its state in biomineralization. The results demonstrate that immobilized CS on collagen fibrils accelerates calcium phosphate nucleation and significantly promotes collagen mineralization by accumulating calcium ions in collagen fibrils. The stochastic optical reconstruction microscopy results confirm that CS gives the specific nucleation sites for calcium phosphate to preferentially form, the improved intrafibrillar heterogeneous nucleation of calcium phosphate facilitates intrafibrillar mineralization. It is found remarkably accelerated remineralization of CS immobilized demineralized dentin is achieved. This study offers insight on the understanding of the function of the biomacromolecule CS on the biomineralization front. In addition, CS effectively promotes intrafibrillar mineralization, which highlights fine prospect for CS to reconstruct collagen-mineralized tissues as a natural material.


Assuntos
Sulfatos de Condroitina/química , Colágeno/química , Fosfatos de Cálcio/química , Fosfatos de Cálcio/metabolismo , Colágeno/metabolismo , Dentina/química , Dentina/metabolismo , Módulo de Elasticidade , Dureza , Hidrogéis/química
16.
Rapid Commun Mass Spectrom ; 34(8): e8674, 2020 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-31769096

RESUMO

RATIONALE: The use of multi-isotopic analysis (δ2 H, δ13 C, δ15 N, δ18 O, and δ34 S values) of modern human body tissues for provenancing of unknown individuals in forensics is increasing. Tooth dentine develops during childhood and adolescence, therefore providing geographical information from that period of life. Tooth apatite δ18 O values are commonly used for the reconstruction of drinking water values, and H-C-N-S isotope ratios in collagen supply additional information about the composition of diet. We tested if dentine collagen δ2 H values provide similar information to apatite δ18 O values with a proof-of-concept study. METHODS: Tooth samples were taken from modern-day individuals born in different regions of the world. Apatite and collagen were prepared from dentine. Stable isotope analyses were performed on apatite phosphate oxygen (δ18 Ophos ); oxygen and carbon of the structural carbonate (δ18 Ocarb , δ13 Ccarb ); and hydrogen, carbon, nitrogen, and sulfur of the collagen (δ2 Hcoll, δ13 Ccoll , δ15 N, δ34 S). RESULTS: δ18 Ophos , δ18 Ocarb , and δ2 Hcoll values are highly correlated in modern human dentine. There are significant relationships of δ18 O values in the apatite fraction and δ2 H values in the collagen fraction with local δ18 O and δ2 H precipitation values, respectively. Pearson correlation coefficients indicate no direct relationship between δ15 N values and the isotope ratios of any other element. Weak relationships exist between collagen δ34 S values and δ18 Ocarb or δ18 Ophos values. CONCLUSIONS: The highly significant correlation of δ18 Ophos , δ18 Ocarb , and δ2 Hcoll values in the modern human dentine implies that measurement of δ2 H values in collagen or δ18 O values in bioapatite will provide reliable information about the climate at the person's whereabouts.


Assuntos
Apatitas/química , Colágeno/química , Dentina/química , Dente/química , Isótopos de Carbono/análise , Deutério/análise , Ciências Forenses , Geografia , Humanos , Espectrometria de Massas , Isótopos de Oxigênio/análise , Fosfatos/química , Isótopos de Enxofre/análise
17.
Clin Oral Investig ; 24(3): 1151-1160, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31292776

RESUMO

OBJECTIVES: The aim of this study was to describe the histological and clinical outcome of "dentin block" (a mixture of autologous particulate dentin, leukocyte- and platelet-rich fibrin (L-PRF), and liquid fibrinogen) in alveolar ridge preservation. MATERIAL AND METHODS: Ten extraction sockets were grafted with "dentin block," a mixture of particulate autologous dentin with chopped leukocyte-platelet-rich fibrin (L-PRF) membranes at a 1:1 ratio, and liquid fibrinogen as a binder. Two grafted sites were followed at 4 and 5 months, and 6 sites at 6 months. Biopsies were taken from the core of the grafted site for histologic and histo-morphometric analysis. RESULTS: All patients completed the study without any adverse event. The vertical and horizontal dimensions of the alveolar ridge were preserved or even increased after 4, 5, or 6 months and remained stable after 6 months of the implant placement. The histological examination revealed a median relative percentage of bone, dentin, and connective tissue of 57.0, 0.9, and 39.3%, respectively. A comparison of samples at different time points (4, 5, and 6 months) showed a progressive increase in the proportion of bone with a decrease in the proportion of dentin. The bone was compact with normal osteocytes and moderate osteoblastic activity. In 4 out of 10 samples, no dentin was observed; in the other samples, it represented 1-5% (with geometric fragments). CONCLUSIONS: Dentin block showed to be a suitable bone substitute in an alveolar ridges preservation model. CLINICAL RELEVANCE: The promising results of dentin block as a bone substitute in alveolar ridge preservation could have an important clinical impact considering this biomaterial brings together the regenerative potential of three autologous products with excellent biological and clinical behavior, low risk of adverse effects, and feasible acquisition.


Assuntos
Aumento do Rebordo Alveolar , Substitutos Ósseos/uso terapêutico , Dentina/química , Fibrinogênio/química , Fibrina Rica em Plaquetas/química , Adulto , Feminino , Humanos , Pessoa de Meia-Idade , Projetos Piloto , Extração Dentária , Alvéolo Dental
18.
Lasers Med Sci ; 35(1): 173-179, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31273570

RESUMO

The purposes of the study were to evaluate the bond strength of bioceramic TotalFill root repair material (RRM) in retrograde cavities prepared using Er:YAG and Er,Cr:YSGG laser and steel bur, and to analyze failure modes. The root canals of 30 single-rooted teeth were endodontically treated, their root-ends were resected using a diamond bur, and the teeth were randomly divided into three groups (N = 10) according to the retrograde cavity preparation technique: (1) Er:YAG laser, (2) Er,Cr:YSGG laser, and (3) steel bur. All retrograde cavities were filled with the TotalFill RRM which was prepared according to the manufacturers' instructions. Push-out test was performed using universal testing machine, and failure mode was analyzed using a scanning electron microscope. The data were analyzed using one-way ANOVA, post hoc analysis with Bonferroni correction, and Fisher-Freeman-Halton exact test (p < 0.05). In the Er:YAG-, Er,Cr:YSGG-, and steel bur-prepared cavities, mean bond strengths (MPa) were 12.76, 8.44, and 6.01, respectively. The bond strength of the TotalFill RRM to dentin was significantly higher in the Er:YAG laser compared with the steel bur-prepared cavities (p = 0.004). The bond strength was not significantly different between the Er:YAG and Er,Cr:YSGG cavities (p = 0.074) and between the Er,Cr:YSGG and bur cavities (p = 0.648). In the cavities prepared by the Er,Cr:YSGG laser and bur, the failure mode of the TotalFill RRM was predominantly mixed, then adhesive and cohesive. In the Er:YAG laser-prepared cavities, the most common failure mode was adhesive, followed by mixed type and no cohesive failure. The bond strength of the TotalFill RRM to dentin was highest in the group of retrograde cavities prepared by the Er:YAG laser.


Assuntos
Cerâmica/química , Colagem Dentária/métodos , Dentina/química , Dentina/efeitos da radiação , Lasers de Estado Sólido , Raiz Dentária/química , Raiz Dentária/efeitos da radiação , Adesivos Dentinários/química , Humanos
19.
Mater Sci Eng C Mater Biol Appl ; 106: 110283, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31753393

RESUMO

The aim of this study was to characterize glycolic acid (GA) and examine its effects on powder and flexural strength of dentin. Particle size and energy-dispersive EDS in GA powder was performed for chemical analysis. Surface tension and pH levels of ethylenediaminetetraacetic acid (EDTA), citric acid (CA), and GA solutions were evaluated at different times and temperatures. Dentin powder and mineralized dentin beams were immersed for 1 min in EDTA, CA, or GA solutions and subjected to Fourier transform infrared spectroscopy for apatite/collagen ratio analysis and 3-point flexure test, respectively. GA showed the largest particle size (µm), and its surface tension was similar to that of EDTA and CA. Surface tension decreased in solutions of higher concentrations. GA showed pH stability at all times and temperatures evaluated. The apatite/collagen ratio reduced with increased GA concentrations, while flexural strength was not significantly affected by GA concentration. GA seems a good choice as a final irrigation solution after root canal preparation.


Assuntos
Dentina/química , Glicolatos/química , Ácido Cítrico/química , Colágeno/química , Colágeno/metabolismo , Cavidade Pulpar/efeitos dos fármacos , Dentina/efeitos dos fármacos , Ácido Edético/química , Resistência à Flexão , Glicolatos/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Tamanho da Partícula , Desnaturação Proteica , Irrigantes do Canal Radicular/química , Irrigantes do Canal Radicular/farmacologia , Tensão Superficial , Temperatura
20.
Arch Oral Biol ; 109: 104552, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31541843

RESUMO

OBJECTIVES: The aim of this in vitro study was to investigate the behavior of osteoblasts on titanium discs under different concentrations of enamel matrix derivatives (EMD) and dentin matrix derivative (DMD). MATERIALS AND METHODS: MC3T3-E1 osteoblast-like cells were cultivated on coated titanium SLA discs with EMD or DMD at 100 µg/ml, 1 mg/ml, 10 mg/ml and 30 mg/ml or left uncoated. Cell viability, proliferation, adhesion and migration were assessed respectively with MTT, BrdU, DAPI and scratch wound healing assays. Messenger ribonucleic acid of different genes related to osteoblastic differentiation was quantified by means of real-time quantitative PCR. Data were analyzed using student t-test for adhesion and migration assay and ANOVA for proliferation assay (p < 0.05). RESULTS: BrdU incorporation was found in proliferative osteoblasts for both test solutions at all concentrations. Osteoblast migrated and covered approximately 70% of the wound area observed at time zero when exposed to EMD and DMD to all concentrations. The increase of gene expression was dependent on the concentration enhancement of EMD and DMD. Higher concentrations showed proliferation augmentation if compared to lower concentrations. CONCLUSIONS: Roughness surface of Ti SLA can limit cell adhesion independent of the presence EMD or DMD. DMD enhances cell migration of osteoblasts on SLA titanium implants in a concentration-dependent manner.


Assuntos
Proteínas do Esmalte Dentário/química , Implantes Dentários , Dentina/química , Osteoblastos/citologia , Titânio , Células 3T3 , Animais , Diferenciação Celular , Proliferação de Células , Camundongos , Propriedades de Superfície
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