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1.
J Appl Oral Sci ; 28: e20190105, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31800873

RESUMO

Calcium aluminate cement (CAC) has been highlighted as a promising alternative for endodontic use aiming at periapical tissue repair. However, its effects on dental pulp cells have been poorly explored. OBJECTIVE: This study assessed the impact of calcium chloride (CaCl2) and bismuth oxide (Bi2O3) or zinc oxide (ZnO) additives on odontoblast cell response to CAC. METHODOLOGY: MDPC-23 cells were exposed for up to 14 d: 1) CAC with 2.8% CaCl2 and 25% ZnO (CACz); 2) CAC with 2.8% CaCl2 and 25% Bi2O3 (CACb); 3) CAC with 10% CaCl2 and 25% Bi2O3 (CACb+); or 4) mineral trioxide aggregate (MTA), placed on inserts. Non-exposed cultures served as control. Cell morphology, cell viability, gene expression of alkaline phosphatase (ALP), bone sialoprotein (BSP), and dentin matrix protein 1 (DMP-1), ALP activity, and extracellular matrix mineralization were evaluated. Data were compared using ANOVA (α=5%). RESULTS: Lower cell density was detected only for MTA and CACb+ compared with Control, with areas showing reduced cell spreading. Cell viability was similar among groups at days one and three (p>0.05). CACb+ and MTA showed the lowest cell viability values at day seven (p>0.05). CACb and CACb+ promoted higher ALP and BSP expression compared with CACz (p<0.05); despite that, all cements supported ALP activity. Matrix mineralization were enhanced in CACb+ and MTA. CONCLUSION: In conclusion, CAC with Bi2O3, but not with ZnO, supported the expression of odontoblastic phenotype, but only the composition with 10% CaCl2 promoted mineralized matrix formation, rendering it suitable for dentin-pulp complex repair.


Assuntos
Compostos de Alumínio/química , Compostos de Alumínio/farmacologia , Compostos de Cálcio/química , Compostos de Cálcio/farmacologia , Cimentos Dentários/química , Cimentos Dentários/farmacologia , Polpa Dentária/citologia , Polpa Dentária/efeitos dos fármacos , Fosfatase Alcalina/análise , Fosfatase Alcalina/efeitos dos fármacos , Animais , Bismuto/química , Bismuto/farmacologia , Cloreto de Cálcio/química , Cloreto de Cálcio/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Combinação de Medicamentos , Expressão Gênica/efeitos dos fármacos , Teste de Materiais , Camundongos , Odontoblastos/efeitos dos fármacos , Óxidos/química , Óxidos/farmacologia , Reprodutibilidade dos Testes , Silicatos/química , Silicatos/farmacologia , Fatores de Tempo , Óxido de Zinco/química , Óxido de Zinco/farmacologia
2.
Infect Immun ; 87(12)2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31527130

RESUMO

Candida-associated denture stomatitis (DS) is a persistent and chronic oral infection of the denture-bearing palatal mucosa. DS stems from the ability of the fungal opportunistic pathogen Candida albicans to adhere to denture material and invade palatal tissue. Although DS is the most prevalent form of oral candidiasis, there are currently no feasible therapeutic strategies for the prevention of this recurrent condition. We developed a peptide-based antimicrobial bioadhesive formulation specifically designed for oral topical formulation. In this study, we aimed to evaluate the applicability of the novel formulation for the prevention of C. albicans colonization on denture material and development of clinical disease. To that end, using the latest technological advances in dental digital design and three-dimensional (3D) printing, we fabricated an intraoral device for rats with universal fit. The device was successfully installed and used to develop clinical DS. Importantly, by taking a preventative therapeutic approach, we demonstrated the potential clinical utility of the novel formulation as a safe and feasible prophylactic agent against DS.


Assuntos
Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Candidíase Bucal/prevenção & controle , Cimentos Dentários/farmacologia , Estomatite sob Prótese/prevenção & controle , Animais , Antifúngicos/química , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Candida albicans/crescimento & desenvolvimento , Candidíase Bucal/tratamento farmacológico , Candidíase Bucal/microbiologia , Cimentos Dentários/química , Dentaduras/microbiologia , Modelos Animais de Doenças , Masculino , Mucosa Bucal/microbiologia , Ratos , Ratos Sprague-Dawley , Estomatite sob Prótese/tratamento farmacológico , Estomatite sob Prótese/microbiologia
3.
Comput Methods Biomech Biomed Engin ; 22(10): 953-960, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31045456

RESUMO

The mechanical properties of the adhesive cement used in resin-bonded fixed partial dentures (RBFPD) can modify the clinical performance of the rehabilitation. The goal of this study was to evaluate the influence of the elastic modulus of different cements on the stress distribution in RBFPD using finite element analysis. For that an anterior 3-unit prosthesis was modeled based in a stereolithography file. The model was meshed with tetrahedral elements and materials considered isotropic, linearly elastic and homogeneous. The force applied to the palatal area of the lateral incisor (pontic) at 45° was 100 N. The cements used presented 7 different elastic modulus (E): 2, 6, 10, 14, 18, 22 or 26 GPa. The total deformation, von-Mises stress and maximum principal stress criteria were used to calculate the results. The lower tensile stress occurred in the cement layer with E = 2 GPa [25.6 (canine) and 16.32 MPa (incisor)]. For the prosthesis, the model with the lower tensile stress [287 (canine) and 248 MPa (incisor)] occurred when the cement presented E = 26 GPa. In this way, the stress concentration may have its magnitude modified depending on the stiffness of the cement. Since more flexible cements concentrate less tensile stress in its structure, but allow an increased displacement of the prosthesis, which is friable and rigid and ends up concentrating more tensile stress at its connector. In that way the clinician should avoid the use of adhesive cement with lower elastic modulus due to it increases the stress concentration in the ceramic.


Assuntos
Cimentos Dentários/farmacologia , Análise do Estresse Dentário , Prótese Adesiva , Cimentos de Resina/farmacologia , Módulo de Elasticidade , Análise de Elementos Finitos , Humanos , Incisivo , Estresse Mecânico
4.
Microsc Res Tech ; 82(7): 1191-1197, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30920097

RESUMO

This study compared the performance of a glass ionomer (GC Gold Label 1, GIC) as a fiber post cementation system for glass fiber posts with a self-adhesive resin cement (Relyx U200, RUC) and a conventional resin cement system (Scotchbond Muli-Purpose and Relyx ARC, RAC). Thirty endodontically treated canines were randomly divided in three groups (n = 10), according to the fiber post cementation system: (RAC)-Scotchbond Multi-Purpose and Relyx X ARC; (RUC)-Relyx U200 and (GIC)-GC Gold Label 1 Luting & Lining. Rhodamine was incorporated into the cementation system prior to the fiber post cementation. After glass fiber post cementation, roots were incubated in artificial saliva for 6 months. After that, specimens from the cervical, middle, and apical thirds of the post space were prepared and analyzed using a push-out bond strength test and confocal laser microscopy. ANOVA one way and Tukey tests showed that GIC and RUC demonstrated similar push-out bond strength values, independently of the post space third (p > .05); however, values were greater than those shown by RAC (p < .05). For dentin penetrability, GIC and RUC also had similar results (p > 0.05) and lower than RAC (p < 0.05). Inside the root canal, the cementation system using glass ionomer cement (GC Gold Label 1 Luting & Lining) has similar push-out bond strength to the self-adhesive resin cement (Relyx U200) and these were higher than the conventional resin (Relyx ARC), despite its higher dentin penetrability.


Assuntos
Cimentos Dentários/química , Cimentos Dentários/farmacologia , Cavidade Pulpar/efeitos dos fármacos , Dentina/efeitos dos fármacos , Cimentos de Ionômeros de Vidro/farmacologia , Cimentação , Resinas Compostas/química , Resinas Compostas/farmacologia , Dente Canino/efeitos dos fármacos , Colagem Dentária , Humanos , Teste de Materiais , Cimentos de Resina/farmacologia , Preparo de Canal Radicular
5.
Braz Oral Res ; 33: e010, 2019 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-30892409

RESUMO

This in situ study aimed to evaluate the antibacterial and anti-demineralization effects of an experimental orthodontic adhesive containing triazine and niobium phosphate bioglass (TAT) around brackets bonded to enamel surfaces. Sixteen volunteers were selected to use intra-oral devices with six metallic brackets bonded to enamel blocks. The experimental orthodontic adhesives were composed by 75% BisGMA and 25% TEGDMA containing 0% TAT and 20% TAT. Transbond XT adhesive (TXT) was used as a control group. Ten volunteers, mean age of 29 years, were included in the study. The six blocks of each volunteer were detached from the appliance after 7 and 14 days to evaluate mineral loss and bacterial growth including total bacteria, total Streptococci, Streptococci mutans, and Lactobacilli. Statistical analysis was performed using GLM model - univariate analysis of variance for microhardness and 2-way ANOVA for bacterial growth (p<0.05). The 20% TAT adhesive caused no difference between distances from bracket and the sound zone at 10-µm deep after 7 and 14 days. After 14 days, higher mineral loss was shown around brackets at 10- to 30-µm deep for TXT and 0% TAT adhesives compared to 20% TAT. S. mutans growth was inhibited by 20% TAT adhesive at 14 days. Adhesive with 20% TAT showed lower S. mutans and total Streptococci growth than 0% TAT and TXT adhesives. The findings of this study show that the adhesive incorporated by triazine and niobium phosphate bioglass had an anti-demineralization effect while inhibiting S. mutans and total Streptococci growth. The use of this product may inhibit mineral loss of enamel, preventing the formation of white spot lesions.


Assuntos
Antibacterianos/farmacologia , Cimentos Dentários/farmacologia , Lactobacillus/efeitos dos fármacos , Nióbio/farmacologia , Óxidos/farmacologia , Fosfatos/farmacologia , Streptococcus/efeitos dos fármacos , Desmineralização do Dente/prevenção & controle , Adulto , Antibacterianos/química , Cerâmica/química , Cerâmica/farmacologia , Cimentos Dentários/química , Método Duplo-Cego , Feminino , Humanos , Masculino , Adulto Jovem
6.
Lasers Med Sci ; 34(7): 1493-1501, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30830558

RESUMO

The proanthocyanidin (PA)-rich grape seed extract (GSE) is a collagen cross-linking agent that can perform a chemical bond with the dentin's collagen. The objective of this study was to evaluate the influence on shear bond strength (SBS) of the pre-conditioning of GSE, on human dentin surfaces conditioned with Er,Cr:YSGG laser. The sample consisted of 64 non-carious human teeth, divided into eight groups, four groups conditioned with Er,Cr:YSGG laser (4.5 W, 50 Hz, 50 µs, 70% air, 90% water) and four prepared with conventional methods (control). In both groups, a GSE solution was applied before using the two adhesives tested: Clearfil™ SE Bond (CSE) and Scotchbond™ Universal (SU). Subsequently, a SBS test, a scanning electron microscopy, and a statistical analysis were performed. In the laser groups, the best SBS mean (20.08 ± 4.01 MPa) was achieved in the group treated with GSE and CSE. The control group with the application of CSE showed the highest SBS mean (24.27 ± 10.28 MPa), and the group treated with laser and SU showed the lowest SBS mean (12.94 ± 6.51 MPa). Between these two groups there was a statistically significant difference (p = 0.05). However, this was not observed among the laser or control groups. The type of dentin surface preparation can influence the SBS. The CSE showed better SBS in laser and control groups. The presence of GSE did not improve the adhesion on surfaces conditioned with laser, but more studies should be carried out in the future to confirm this conclusion.


Assuntos
Cimentos Dentários/farmacologia , Dentina/efeitos dos fármacos , Dentina/efeitos da radiação , Extrato de Sementes de Uva/farmacologia , Lasers de Estado Sólido , Colagem Dentária , Dentina/ultraestrutura , Humanos , Propriedades de Superfície
7.
Microsc Res Tech ; 82(5): 538-543, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30614122

RESUMO

The purpose of this study was to evaluate the micro-tensile bond strength (µTBS) of dentin bonding agents containing different ratios of nano-sized hydroxyapatite fillers (HA). X-ray diffraction analysis was used for characterization, and scanning electron microscope (SEM) analysis was used to determine the HA particle size after that HA were mixed a bonding agents without filler. Dentin bonding agents were divided into four groups according to addition of different ratios of nano-sized hydroxyapatite fillers as 2% HA, 5% HA, 7% HA, and no-filler control group. The teeth (n = 32) were sectioned with a low-speed diamond blade under water cooling to expose the mid-coronal dentin. Following the bonding application, restorations were applied incrementally. Each tooth was cut on the x and y axis, and each specimen was fixed to a testing device and stressed until failure occurred. The debonded specimens were examined under 250× magnification without a coating layer at 2.00 kV using a SEM to determine failure patterns. µTBS data were analyzed using a anova and Tukey's post hoc test. The failure mode data were analyzed using the Chi-Square test. The maximum mean value of µTBS was in the 7% HA group, while the minimum mean value of µTBS was observed in the control group. 7% HA group was statistically significant and higher than other groups while there were no significant differences between the control, 2% HA, and 5% HA groups. According to SEM analysis, fracture analysis revealed that the mixed fracture type was seen more often than the other fracture types. The particle size and amount of HA fillers added to the adhesive resin seem to affect the success of the bond strength to the dentin. Adding different ratio nano-sized HA fillers to the adhesive resin contributed positively to the immediate µTBS values in the dentin.


Assuntos
Materiais Biocompatíveis/análise , Cimentos Dentários/química , Cimentos Dentários/farmacologia , Durapatita/análise , Fenômenos Mecânicos , Nanoestruturas/análise , Humanos , Microscopia Eletrônica de Varredura , Dente Molar , Difração de Raios X
8.
J Appl Oral Sci ; 27: e20180247, 2019 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-30624470

RESUMO

OBJECTIVE: This study aimed to investigate the effects of dodecacalcium hepta-aluminate (C12A7) content on some physicochemical properties and cytocompatibility of tricalcium silicate (C3S) cement using human dental pulp cells (hDPCs). MATERIAL AND METHODS: High purity C3S cement was manufactured by a solid phase method. C12A7 was mixed with the cement in proportions of 0, 5, 8, and 10 wt% (C12A7-0, -5, -8, and -10, respectively). Physicochemical properties including initial setting time, compressive strength, and alkalinity were evaluated. Cytocompatibility was assessed with cell viability tests and cell number counts. Statistical analysis was performed by using one-way analysis of variance (ANOVA) and Tukey's test (p<0.05). RESULTS: The initial setting time of C3S-based cement was shorter in the presence of C12A7 (p<0.05). After 1 day, C12A7-5 showed significantly higher compressive strength than the other groups (p<0.05). After 7 days, the compressive strength of C12A7-5 was similar to that of C12A7-0, whereas other groups showed strength lower than C12A7-0. The pH values of all tested groups showed no significant differences after 1 day (p>0.05). The C12A7-5 group showed similar cell viability to the C12A7-0 group (p>0.05), while the other experimental groups showed lower values compared to C12A7-0 group (p<0.05). The number of cells grown on the C12A7-5 specimen was higher than that on C12A7-8 and -10 (p<0.05). CONCLUSIONS: The addition of C12A7 to C3S cement at a proportion of 5% resulted in rapid initial setting time and higher compressive strength with no adverse effects on cytocompatibility.


Assuntos
Compostos de Alumínio/química , Compostos de Cálcio/química , Cimentos Dentários/química , Cavidade Pulpar/citologia , Silicatos/química , Compostos de Alumínio/farmacologia , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Compostos de Cálcio/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Força Compressiva , Cimentos Dentários/farmacologia , Cavidade Pulpar/efeitos dos fármacos , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Valores de Referência , Reprodutibilidade dos Testes , Silicatos/farmacologia , Fatores de Tempo , Difração de Raios X
9.
Mater Sci Eng C Mater Biol Appl ; 97: 116-123, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30678896

RESUMO

Metal oxide nanoparticles are a new class of important materials used in a wide variety of biomedical applications. Bulk zinc oxide (ZnO) particles have been used for temporal or permanent luting cement because of their excellent mechanical strength and biocompatibility. ZnO nanoparticles have distinct optical and antibacterial properties and a high surface-to-volume ratio. We investigated the mechanical and antibacterial properties of luting cement with different ratios of ZnO nanospheres. We showed that luting cement with 5% and 10% ZnO nanospheres was less soluble in low-pH (pH 3) artificial saliva. Antibacterial activity was 40% higher for Streptococcus mutans and 90% higher for Porphyromonas gingivalis when >10% (w/v) of the bulk particles were replaced with ZnO nanospheres in ZnO polycarboxylate cement. ZnO nanospheres were also biocompatible with mammalian cells. Additionally, the compressive strength was 1.2 times greater and the diametral tensile strength was 1.5 times greater for cements with 10% ZnO nanospheres than for conventional ZnO polycarboxylate cement. We propose a new method for improving dental luting cement by integrating it with ZnO nanospheres. This method simultaneously adds their greater antibacterial, mechanical, and acid resistance properties and retains an outstanding degree of biocompatibility.


Assuntos
Antibacterianos/farmacologia , Cimentos Dentários/química , Cimentos Dentários/farmacologia , Nanosferas/química , Óxido de Zinco/química , Animais , Antibacterianos/química , Implantes Dentários , Relação Dose-Resposta a Droga , Concentração de Íons de Hidrogênio , Teste de Materiais , Camundongos , Cimento de Policarboxilato/química , Cimento de Policarboxilato/farmacologia , Porphyromonas gingivalis/efeitos dos fármacos , Saliva/química , Streptococcus mutans/efeitos dos fármacos , Resistência à Tração , Óxido de Zinco/administração & dosagem , Óxido de Zinco/farmacologia
10.
Photodiagnosis Photodyn Ther ; 25: 239-246, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30611862

RESUMO

BACKGROUND: Potential complications on the crown level during fixed orthodontic procedures are white spot, enamel demineralization and tooth decay. This study evaluated the antimicrobial properties of an orthodontic adhesive incorporating cationic curcumin doped zinc oxide nanoparticles (cCur/ZnONPs), which can have the highest concentration of cCur/ZnONPs and shear bond strength (SBS) value simultaneously, against cariogenic bacteria including Streptococcus mutans, Streptococcus sobrinus, and Lactobacillus acidophilus. MATERIALS AND METHODS: Following synthesis and confirmation of cCur/ZnONPs, SBS and adhesive remnant index (ARI) of the test adhesives containing cCur/ZnONPs (1.2, 2.5, 5, 7.5, and 10% wt.) were measured using universal testing machine and stereomicroscope, respectively. After continuously rinsed (up to 180 day), the residual antimicrobial ability of modified adhesives which can have the highest concentration of cCur/ZnONPs and SBS value simultaneously were determined by disc agar diffusion (DAD), biofilm formation inhibition, and metabolic activity assays following photo-activation using light-emitting diode (LED) for 5 min against multispecies cariogenic biofilm-producing bacteria. RESULTS: Adhesive with 7.5% wt. cCur/ZnONPs showed the highest concentration of cCur/ZnONPs and SBS value (14.89 ± 3.26 MPa, P < 0.05) simultaneously. No significant differences in ARI scores were found between the modified adhesive and control (Transbond XT without the cCur/ZnONPs). 7.5% wt. cCur/ZnONPs following photo-activation was not colonized by the test microorganisms and suppressed 100% metabolic activity of the test microorganisms up to 90 day compared to the control group (cCur/ZnONPs free LED irradiation; P < 0.05). In DAD assay, the reduction of photodynamic disinfection of the 7.5% wt. cCur/ZnONPs against test bacteria was positively associated to the time, in such a way that it was decreased significantly after 60 day. From days 120 onwards, microbial biofilm formation and metabolic activity was progressively increased on 7.5% wt. cCur/ZnONPs adhesive discs compared to the control group (cCur/ZnONPs free LED irradiation). CONCLUSIONS: Our findings highlight the photo-activated 7.5% wt. cCur/ZnONPs can serve as an orthodontic adhesive additive to control the cariogenic multispecies biofilm, and also to reduce their metabolic activity.


Assuntos
Biofilmes/efeitos dos fármacos , Curcumina/farmacologia , Cimentos Dentários/farmacologia , Nanopartículas/administração & dosagem , Fotoquimioterapia/métodos , Óxido de Zinco/farmacologia , Adesividade , Cátions , Curcumina/química , Cimentos Dentários/química , Lactobacillus acidophilus , Nanopartículas/química , Streptococcus mutans , Streptococcus sobrinus , Propriedades de Superfície
11.
Clin Oral Investig ; 23(8): 3213-3218, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30415440

RESUMO

OBJECTIVE: The aim of this in vitro study is to evaluate the effects of resveratrol (RES) addition on the cytotoxicity and microtensile bond strength (µTBS) of different adhesives. MATERIALS AND METHODS: Five self-etching adhesives (G-aenial Bond-GC, Optibond All in One-Kerr, Gluma Self Etch-Kulzer, Clearfil S3 Bond-Kuraray, and Nova Compo-B Plus-Imicryl) were tested. They were applied to L-929 cell culture by the extract method. In the test groups, 0.5 µM RES (Sigma-Aldrich) was added into the medium. Cell viability was assessed by MTT assay after 24 h. Human extracted third molars were used for µTBS test (n = 7). The adhesives with or without 0.5 µM RES addition were applied on dentin surfaces. A composite build-up was constructed. Then, the specimens were sectioned into multiple beams with the non-trimming version of the microtensile test and subjected to microtensile forces. Statistical analysis was performed using ANOVA and post hoc Tukey test (p Ë‚ 0.05). RESULTS: The extracts of all adhesives decreased the cell viability. However, RES addition increased the cell viability in all groups (p Ë‚ 0.05). RES addition did not cause any decrease in µTBS values of the adhesives compared to baseline. Optibond All in One showed the highest µTBS after RES addition. It was followed by Clerafil S3 Bond and Nova Compo-B Plus. No difference was determined between the Optibond All in One and Clearfil S3 Bond. There was difference between Optibond All in One and Nova Compo-B Plus (p Ë‚ 0.05). CONCLUSION: RES addition may improve the biocompatibility without causing negative influence on µTBS of the adhesives. CLINICAL RELEVANCE: RES addition has clinical applicable potential to overcome the adverse biocompatibility of adhesives.


Assuntos
Colagem Dentária , Cimentos Dentários , Resveratrol , Adesivos , Resinas Compostas , Cimentos Dentários/farmacologia , Dentina , Adesivos Dentinários , Humanos , Teste de Materiais , Cimentos de Resina , Resveratrol/farmacologia , Resistência à Tração
12.
Am J Orthod Dentofacial Orthop ; 155(1): 88-97, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30591172

RESUMO

INTRODUCTION: The aim of this study was to determine the effect of an orthodontic bonding adhesive containing benzalkonium chloride (BAC) on enamel demineralization. METHODS: Eighteen female Sprague-Dawley rats, aged 8 to 10 weeks, were inoculated with Streptococcus sobrinus for 5 days. The animals were randomly divided into the control, non-BAC, and BAC groups. The 6 animals in each group did not receive any brackets, received brackets on the maxillary left first molars bonded with conventional adhesive, or received brackets on the maxillary left and right first molars bonded with adhesive incorporated with 0.25% and 0.75% BAC (wt/wt), respectively. After 7 weeks, the maxillae were soaked in murexide stain to observe the surface area (mm2) and percentages of enamel demineralization on the palatal, mesial, buccal, and occlusal surfaces of the maxillary molars using color-based image analysis. RESULTS: The non-BAC and BAC groups exhibited greater enamel demineralization compared with the control group. The surface areas and percentages of enamel demineralization in the BAC group were less compared with the non-BAC group. Less enamel demineralization was noted in the animals treated with 0.75% BAC compared with those given 0.25% BAC in all areas; however, these differences were not great enough to attain statistical significance at the 0.05 level. CONCLUSIONS: The addition of BAC to an orthodontic composite has the potential to reduce the amount and percentage of enamel demineralization. In addition to being an antibacterial agent, BAC may also have an anticariogenic effect. Increased sample sizes and testing of more concentrations of BAC are recommended.


Assuntos
Anti-Infecciosos Locais/uso terapêutico , Compostos de Benzalcônio/uso terapêutico , Cimentos Dentários/uso terapêutico , Desmineralização do Dente/prevenção & controle , Animais , Anti-Infecciosos Locais/farmacologia , Compostos de Benzalcônio/farmacologia , Cárie Dentária/prevenção & controle , Cimentos Dentários/farmacologia , Feminino , Humanos , Ratos , Ratos Sprague-Dawley , Dente/efeitos dos fármacos
13.
Lasers Med Sci ; 34(1): 47-54, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29984399

RESUMO

Root-filled teeth that received fiber posts most frequently fail at the adhesive interface between resin cement and dentin. The objective of this study is to evaluate the effect of Er:YAG laser and/or sodium ascorbate (SA) on bond strength, microhardness of dentin, and penetration depth of cement into dentinal tubules. Forty-eight bovine incisor roots were endodontically treated, post spaces were prepared and equally divided into four groups (n = 12): G1-distilled water (control); G2-10% SA (10 min); G3-Er:YAG laser (150 mJ/4 Hz/40 s), and G4-Er:YAG laser + 10% SA. Glass fiber posts were cemented and roots sectioned into slices. In the first slice, the push-out bond strength (MPa) and failures were analyzed by confocal laser scanning microscope (CLSM). The second slice was subjected to microhardness test (KHN) and CLSM to assess the cement penetration. ANOVA and Tukey test were used for bond strength and microhardness data and Kruskal-Wallis and Dunn tests for the cement penetration (α = .05). The SA-treated samples had higher bond strength (10.02 ± 5.45a), similar to Er:YAG laser (9.91 ± 4.62a) and Er:YAG laser + SA (8.09 ± 4.07a). The least values (P < .05) were found on control (4.02 ± 2.39b). Significant differences were observed on root thirds (P < .05): cervical > middle > apical. There was a predominance of adhesive failures. The microhardness test revealed no differences between groups (P > .05). The experimental groups (G2, G3, and G4) had highest penetration into dentinal tubules when compared to the control (G1). Dentin pretreatments with Er:YAG laser or SA improved bond strength of cement-post-dentin interfaces; however, no synergistic effect of both treatments combined was observed.


Assuntos
Ácido Ascórbico/farmacologia , Colagem Dentária , Dentina/efeitos da radiação , Vidro/química , Lasers de Estado Sólido , Animais , Bovinos , Cimentos Dentários/farmacologia , Dureza , Teste de Materiais , Cimentos de Resina/farmacologia , Raiz Dentária/efeitos dos fármacos , Raiz Dentária/efeitos da radiação
14.
Clin Oral Investig ; 23(3): 1367-1372, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30022269

RESUMO

OBJECTIVES: To assess the viability of multispecies microcosm biofilm after contact with NeoMTA Plus, Biodentine, and MTA Angelus. MATERIALS AND METHODS: Fifty-four human dentin blocks (4 × 5 × 4 mm) were allocated to Hawley retainers, worn by six volunteers for 72 h. The blocks were then individually incubated in BHI broth for 21 days at 37 °C. At the end of experimental time for biofilm growth, the samples were randomly divided into four groups (n = 12): NeoMTA Plus, Biodentine, MTA Angelus, and negative control. The materials were placed in contact with the blocks. All samples were placed in cell-culture plate wells and incubated in BHI broth for 7 days at 37 °C. One sample from each volunteer (n = 6) was analyzed by SEM to describe the biofilm morphology. CLSM was performed to determine the percentage of viable biofilm biovolume. The data were statistically analyzed by one-way ANOVA and Tukey's multiple comparison test (α = 5%). RESULTS: SEM showed biofilm formed by spherical and rod-shaped bacteria surrounded by an extracellular matrix. No material was able to kill all biofilm cells, and all groups had more than 50% of viable bacteria. NeoMTA Plus was significantly different from the negative control group (P < .05). CONCLUSIONS: All tested materials were not effective against multispecies microcosm biofilm. CLINICAL RELEVANCE: NeoMTA Plus, Biodentine, and MTA Angelus were not effective against multispecies microcosm biofilm. It is essential to understand that these bioceramic cements are indicated for infected clinical situations. Thus, complementary disinfection procedures should be conducted prior to filling with these materials.


Assuntos
Anti-Infecciosos/farmacologia , Biofilmes/efeitos dos fármacos , Cimentos Dentários/farmacologia , Bismuto/farmacologia , Compostos de Cálcio/farmacologia , Humanos , Teste de Materiais , Microscopia Confocal , Óxidos/farmacologia , Silicatos/farmacologia
15.
Biointerphases ; 13(6): 061004, 2018 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-30558430

RESUMO

Dentin adhesive systems for composite tooth restorations are composed of hydrophilic/hydrophobic monomers, solvents, and photoinitiators. The adhesives undergo phase separation and concomitant compositional change during their application in the wet oral environment; phase separation compromises the quality of the hybrid layer in the adhesive/dentin interface. In this work, the adhesive composition in the hybrid layer can be represented using the phase boundaries of a ternary phase diagram for the hydrophobic monomer/hydrophilic monomer/water system. The polymer phases, previously unaccounted for, play an important role in determining the mechanical behavior of the bulk adhesive, and the chemomechanical properties of the phases are intimately related to the effects produced by differences in the hydrophobic-hydrophilic composition. As the composition of the polymer phases varies from hydrophobic-rich to hydrophilic-rich, the amount of the adsorbed water and the nature of polymer-water interaction vary nonlinearly and strongly correlate with the change in elastic moduli under wet conditions. The failure strain, loss modulus, and glass transition temperature vary nonmonotonically with composition and are explained based upon primary and secondary transitions observed in dynamic mechanical testing. Due to the variability in composition, the assignment of mechanical properties and the choice of suitable constitutive models for polymer phases in the hybrid layer are not straightforward. This work investigates the relationship between composition and chemomechanical properties of the polymer phases formed on the water-adhesive phase boundary using quasistatic and dynamic mechanical testing, mass transfer experiments, and vibrational spectroscopy.


Assuntos
Cimentos Dentários/química , Cimentos Dentários/farmacologia , Polímeros/química , Polímeros/farmacologia , Fenômenos Químicos , Fenômenos Mecânicos , Relação Quantitativa Estrutura-Atividade
16.
Med Oral Patol Oral Cir Bucal ; 23(6): e646-e655, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30341273

RESUMO

BACKGROUND: The purpose of this study was to evaluate nanohardness and viscoelastic behavior of dentin surfaces treated with two canal sealer cements for dentin remineralization. MATERIAL AND METHODS: Dentin surfaces were subjected to: i) 37% phosphoric acid (PA) or ii) 0.5 M ethylenediaminetetraacetic acid (EDTA) conditioning prior to the application of two experimental hydroxyapatite-based cements, containing sodium hydroxide (calcypatite) or zinc oxide (oxipatite), respectively. Samples were stored in simulated body fluid during 24 h or 21 d. The intertubular and peritubular dentin were evaluated using a nanoindenter to assess nanohardness (Hi). The load/displacement responses were used for the nano-dynamic mechanical analysis to estimate complex modulus (E*) and tan delta (δ). The modulus mapping was obtained by imposing a quasistatic force setpoint to which a sinusoidal force was superimposed. AFM imaging and FESEM analysis were performed. RESULTS: After 21 d of storage, dentin surfaces treated with EDTA+calcypatite, PA+calcypatite and EDTA+oxipatite showed viscoelastic discrepancies between peritubular and intertubular dentin, meaning a risk for cracking and breakdown of the surface. At both 24 h and 21 d, tan δ values at intertubular dentin treated with the four treatments performed similar. At 21 d time point, intertubular dentin treated with PA+oxipatite achieved the highest complex modulus and nanohardness, i.e., highest resistance to deformation and functional mineralization, among groups. CONCLUSIONS: Intertubular and peritubular dentin treated with PA+oxipatite showed similar values of tan δ after 21 d of storage. This produced a favorable dissipation of energy with minimal energy concentration, preserving the structural integrity at the dentin surface.


Assuntos
Cimentos Dentários/farmacologia , Dentina/efeitos dos fármacos , Hidróxido de Sódio/farmacologia , Remineralização Dentária/métodos , Óxido de Zinco/farmacologia , Humanos , Técnicas In Vitro , Teste de Materiais , Propriedades de Superfície
17.
Mater Sci Eng C Mater Biol Appl ; 93: 931-943, 2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-30274130

RESUMO

The development of dental adhesive resins with long-lasting antibacterial properties is a possible solution to overcome the problem of secondary caries in modern adhesive dentistry. OBJECTIVES: (i) Synthesis and characterization of nitrogen-doped titanium dioxide nanoparticles (N_TiO2), (ii) topographical, compositional and wettability characterization of thin-films (unaltered and experimental) and, (iii) antibacterial efficacy of N_TiO2-containing dental adhesives against Streptococcus mutans biofilms. MATERIALS AND METHODS: Nanoparticles were synthesized and characterized using different techniques. Specimens (diameter = 12 mm, thickness ≅ 15 µm) of OptiBond Solo Plus (Kerr Corp., USA) and experimental adhesives [50, 67 and 80% (v/v)] were fabricated, photopolymerized (1000 mW/cm2, 1 min) and UV-sterilized (254 nm, 800,000 µJ/cm2) for microscopy, spectroscopy, wettability and antibacterial testing. Wettability was assessed with a contact angle goniometer by dispensing water droplets (2 µL) onto four random locations of each specimen (16 drops/group). Drop profiles were recorded (1 min, 25 frames/s, 37 °C) and contact angles were calculated at time = 0 s (θINITIAL) and time = 59 s (θFINAL). Antibacterial testing was performed by growing S. mutans (UA159-ldh, JM10) biofilms for either 3 or 24 h (anaerobic conditions, 37 °C) with or without continuous light irradiation (410 ±â€¯10 nm, 3 h = 38.75 J/cm2, 24 h = 310.07 J/cm2) against the surfaces of sterile specimens. RESULTS: N_TiO2 was successfully prepared using solvothermal methods. Doped-nanoparticles displayed higher light absorption levels when compared to undoped titania. Experimental adhesives demonstrated superior antibacterial efficacy in dark conditions. CONCLUSIONS: The findings presented herein suggest that N_TiO2 is a feasible antibacterial agent against cariogenic biofilms.


Assuntos
Antibacterianos , Biofilmes/efeitos dos fármacos , Cimentos Dentários , Nanopartículas/química , Nitrogênio , Streptococcus mutans/fisiologia , Titânio , Antibacterianos/química , Antibacterianos/farmacologia , Biofilmes/crescimento & desenvolvimento , Cimentos Dentários/química , Cimentos Dentários/farmacologia , Nitrogênio/química , Nitrogênio/farmacologia , Titânio/química , Titânio/farmacologia
18.
PLoS One ; 13(10): e0203951, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30304005

RESUMO

OBJECTIVES: To verify whether the Ultra Corega Cream and Corega Strip Denture Adhesive adhesives interfere in the microbial adhesion and biofilm formation by Candida albicans and Lactobacillus casei in single- and mixed-species settings, and observe whether synergistic or antagonistic relationships between these species occur. METHODS: Specimens made from heat-polymerized acrylic resin (Lucitone 550) were fabricated (n = 144) with a circular shape and standardized roughness (3.0 µm ±0.3 Ra) and were divided into three groups: Without Adhesive (WA), with Ultra Corega Cream adhesive (CA) and Corega Strips adhesive (SA). These groups were divided into three subgroups each: C. albicans single-species, L. casei single-species and C. albicans with L. casei (mixed-species). Microbial adhesion and biofilm formation assays were performed in duplicate at four distinct experimental times (n = 8 per experimental condition). The amount of each microorganism on the surfaces of the specimens was observed by counting of the Colony Forming Units (CFU) per substrate. Additional specimens were characterized by Scanning Electron Microscopy (SEM), with 18 specimens being used in this analysis (n = 18), 2 per experimental condition (n = 2). Two-way ANOVA and Tukey's test for multiple comparisons were employed, using α≤0.05. RESULTS: L. casei (mixed-species) adhered more on the WA substrate than the CA, while C. albicans (single- and mixed-species) adhered more on the SA. C. albicans, both single- and mixed-species adhered more than the L. casei (single- and mixed-species), regardless of the substrate. L. casei (single-species) formed more biofilm on the WA, but in its mixed cultivation, it had no difference of growth among the tested situations. C. albicans (single- and mixed-species) formed more biofilm on the SA than the CA, and the fungus formed more biofilm when compared to L. casei. In general, whenever a species was compared in its single- and mixed-species situation, no statistically significant difference was observed. SEM of biofilm formation assays demonstrated that L. casei single-species WA formed more biofilm than when the adhesives tested were used, and C. albicans (both single- and mixed-species) formed more biofilm on the SA than on the CA. CONCLUSIONS: (1) The two denture adhesives tested increased the adhesion of C. albicans but not of L. casei; (2) biofilm formation by C. albicans (single- and mixed-species) was increased on the SA; (3) Relations of synergism or antagonism was not observed between the two microorganisms studied.


Assuntos
Aderência Bacteriana/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Cimentos Dentários/farmacologia , Retenção de Dentadura/métodos , Biofilmes/crescimento & desenvolvimento , Candida albicans/efeitos dos fármacos , Candida albicans/fisiologia , Contagem de Colônia Microbiana , Prótese Total , Lactobacillus casei/efeitos dos fármacos , Lactobacillus casei/fisiologia , Microscopia Eletrônica de Varredura , Especificidade da Espécie , Propriedades de Superfície
19.
J Dent ; 78: 83-90, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30153498

RESUMO

OBJECTIVES: This work aims to explore the feasibility of chlorhexidine-encapsulated mesoporous silica (CHX@pMSN) as a modifier of a commercial dental adhesive via the evaluation of physicochemical properties and antibacterial capabilities of adhesive-dentin interface. METHODS: Therapeutic adhesives were developed in the present study by incorporating CHX@pMSN into a commercial adhesive at four mass fractions (0, 1, 5 and 10 wt.%). The antibacterial capability on Streptococcus mutans (S. mutans) biofilm, conversion degree, adhesive morphology, microtensile bond strength (MTBS) and nanoleakage expression were evaluated comprehensively. RESULTS: MTT and CLSM evaluation showed that CHX@pMSN-doped adhesive inhibits S. mutans biofilm growth, while CHX is released from the modified adhesive continuously. The incorporation of CHX@pMSN did not affect immediate bond strength at the concentration of 1% and 5% (P > 0.05). Moreover, these bonds were mainly preserved in 5% CHX@pMSN group after one month of collagenase ageing. Meanwhile, CHX@pMSN-doped adhesive groups exhibited similar nanoleakage distribution compared with the control. CONCLUSION: This study showed that the 5% CHX@pMSN-modified adhesive achieved balance amongst unaffected immediate bonding strength, well-preserved bonds against collagenase ageing and effective inhibition of S. mutans biofilm growth. CLINICAL SIGNIFICANCE: CHX@pMSN-modified dentin adhesive can potentially extend the service life of adhesive restoration in clinic.


Assuntos
Fenômenos Químicos , Clorexidina , Cimentos Dentários , Dióxido de Silício , Antibacterianos/química , Antibacterianos/farmacologia , Fenômenos Químicos/efeitos dos fármacos , Clorexidina/química , Clorexidina/farmacologia , Colagem Dentária/normas , Cimentos Dentários/química , Cimentos Dentários/farmacologia , Teste de Materiais , Dióxido de Silício/química , Streptococcus mutans/efeitos dos fármacos
20.
J Dent ; 78: 91-99, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30153499

RESUMO

OBJECTIVES: The objectives were to develop a calcium (Ca) and phosphate (P) ion-rechargeable and protein-repellent adhesive containing nanoparticles of amorphous calcium phosphate (NACP) and 2-methacryloyloxyethyl phosphorylcholine (MPC), and investigate the MPC effects on ion recharge and re-releases for the first time. METHODS: Pyromellitic glycerol dimethacrylate and ethoxylated bisphenol-A dimethacrylate were used to fabricate adhesive PEHB. Six adhesives were tested: (1) Scotchbond (SBMP); (2) PEHB, (3) PEHB + 20%NACP; (4) PEHB + 30%NACP; (5) PEHB + 20%NACP+3%MPC; (6) PEHB + 30%NACP+3%MPC. Dentin shear bond strength, Ca/P ion release, recharge and re-release, and protein adsorption were measured. A microcosm biofilm model was tested for lactic-acid production and colony-forming units (CFU). RESULTS: Adding NACP + MPC did not negatively affect dentin bond strength (p > 0.1). With increasing the number of recharge/re-release cycles, the Ca/P ion re-release reached similarly higher levels (p > 0.1), indicating long-term remineralization capability. One recharge enabled the adhesives to have continued re-releases for 21 days. Incorporation of 3% MPC yielded 10-fold decrease in protein adsorption, and 1-2 log decrease in biofilm CFU. CONCLUSIONS: The new rechargeable adhesive with MPC + 30%NACP greatly reduced protein adsorption, biofilm growth and lactic acid. Incorporation of MPC did not compromise the excellent Ca/P ion release, rechargeability, and dentin bond strength. CLINICAL SIGNIFICANCE: Novel bioactive adhesive containing MPC + NACP is promising to repel proteins and bacteria, and inhibit secondary caries at the restoration margins. The method of NACP + MPC to combine CaP-recharge and protein-repellency is applicable to the development of a new generation of materials including composites and cements to suppress oral biofilms and plaque formation and protect tooth structures.


Assuntos
Fosfatos de Cálcio , Cimentos Dentários , Íons , Nanopartículas , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Fosfatos de Cálcio/química , Fosfatos de Cálcio/farmacologia , Cimentos Dentários/química , Cimentos Dentários/farmacologia , Íons/química , Teste de Materiais , Metacrilatos/química , Metacrilatos/farmacologia , Nanopartículas/química
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