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1.
J Indian Prosthodont Soc ; 23(1): 45-49, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36588374

RESUMO

Aim: The intention was to determine the chemical interaction of silanized AgNPs with PMMA by Fourier transform infrared (FTIR) spectroscopy. Settings and Design: In-vitro comparative study. Materials and Methods: This study is composed of four groups - 0.75% AgNP, 1.0% AgNP, 1.5% AgNP impregnated with PMMA, and nonimpregnated PMMA as control. The chemical nature of silanized AgNPs was studied using FTIR study. Results: The results showed the appearance of new peak between 1727/cm and 1436/cm, i.e., 1636.476/ cm, 1645.886/cm, and 1646.885/cm, representing the C = C stretch in the experimental groups, i.e., 2, 3, and 4, respectively. This peak confirms that coupling agent has chemically interacted with PMMA. Conclusion: It can be concluded that the AgNPs coated with the silane coupling agent TMSPM has chemically reacted with PMMA.


Assuntos
Nanopartículas Metálicas , Polimetil Metacrilato , Polimetil Metacrilato/química , Prata , Teste de Materiais , Nanopartículas Metálicas/química , Bases de Dentadura , Metacrilatos
2.
Int J Mol Sci ; 24(2)2023 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-36674421

RESUMO

Silanized glass fibers are popular reinforcements of acrylic denture base materials. To increase the number of surface hydroxyl groups and to improve interfacial adhesion between the matrix and reinforcements, acid or base treatments of glass fibers are commonly performed before the silanization. However, limited data are available on the effect of these treatments on the mechanical properties of acrylic matrix composite materials used for denture base applications. In this work, before the silanization of a woven glass fiber fabric (GF) with 3-(trimethoxysilyl) propyl methacrylate, activation pretreatments using HCl and NH4OH aqueous solutions have been performed. To characterize the glass surface, FTIR spectroscopy was used. Specimens of cured acrylic denture base resin and composites were divided into five groups: (1) cured acrylic denture base resin-control group; (2) composite with non-silanized GF; (3) composite with silanized GF; (4) composite with NH4OH activated and silanized GF; (5) composite with HCl activated and silanized GF. The flexural and impact properties of specimens were evaluated by means of three-point-bending tests and Charpy impact testing, respectively. The residual reactivity of the samples was analyzed using differential scanning calorimetry. The results of mechanical testing showed that acid and base pretreatments of the glass fabric had a positive effect on the flexural modulus of prepared composites but a negative effect on their impact strength. Possible interfacial adhesion mechanisms and the diffusion control of isothermal cure reactions due to vitrification have been discussed.


Assuntos
Bases de Dentadura , Polimetil Metacrilato , Polimetil Metacrilato/química , Teste de Materiais , Análise de Variância , Vidro/química , Resinas Acrílicas/química , Propriedades de Superfície , Estresse Mecânico
3.
J Mech Behav Biomed Mater ; 138: 105634, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36543086

RESUMO

Poly (methyl methacrylate) (PMMA) is a commonly used material for the fabrication of biomedical appliances. Although PMMA has several advantages, it is susceptible to microbial insults with practical use. Therefore, different bioactive nanomaterials, such as nanoceria (CeN), have been proposed to enhance the properties of PMMA. In this study, we investigated the effect of the incorporation of CeN into PMMA with and without the use of mesoporous silica nanoparticle (SBA-15) carriers. The unmodified PMMA specimens (control, CTRL) were compared to groups containing SBA-15, CeN, and the synthesized SBA-15 impregnated with CeN (SBA-15@CeN) at different loading percentages. The mechanical and physical properties of the different SBA-15@CeN groups and their effects on cell viability were investigated, and the optimal CeN concentration was identified accordingly. Our results revealed that flexural strength was significantly (P < 0.01) reduced in the SBA-15@CeN3× group (containing 3-fold the CeN wt. %). Although the surface microhardness increased with the increase in the wt. % of SBA-15@CeN, cell viability was significantly reduced (P < 0.001). The SBA-15@CeN1× group had the optimal concentration and displayed significant resistance to single-and multispecies microbial colonization. Finally, the enzymatic activity of CeN was significantly high in the SBA-15@CeN1× group. The proinflammatory markers (IL-6, IL-1ß, TNF-α, CD80, and CD86) showed a significant (P < 0.001) multifold reduction in lipopolysaccharide-induced RAW cells treated with a 5-day eluate of the SBA-15@CeN1× group. These results indicate that the addition of SBA-15@CeN at 1.5 wt % improves the biological response of PMMA without compromising its mechanical properties.


Assuntos
Bases de Dentadura , Polimetil Metacrilato , Dióxido de Silício , Propriedades de Superfície , Teste de Materiais
4.
J Prosthet Dent ; 129(1): 228.e1-228.e8, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36476985

RESUMO

STATEMENT OF PROBLEM: Polymethyl methacrylate (PMMA) is commonly used in dentistry, including as a denture base material. However, the colonization of a PMMA surface by microbial microorganisms could increase the risk of oral diseases such as denture stomatitis and gingivitis. The development of PMMA with antibacterial properties should improve its clinical application, but whether adding ε-poly-L-lysine (ε-PL) and 2-methacryloyloxyethyl phosphorylcholine (MPC) provides antimicrobial effects is unclear. PURPOSE: This in vitro study aimed to develop a novel antibacterial PMMA resin containing the natural nontoxic antibacterial agent ε-PL and the protein repellent agent MPC. The mechanical properties, protein repellency, and antimicrobial activities of the resin were then evaluated. MATERIAL AND METHODS: Different mass fractions of ε-PL and MPC were mixed into PMMA as the experimental groups, with unaltered PMMA as the control group. The flexural strength (n=10) and surface roughness (n=6) of the resulting mixtures were measured to determine their mechanical properties. The antiprotein properties were measured by using the micro bicinchoninic acid method (n=6). The antimicrobial effect of the resin was assessed using live/dead staining (n=6) and methyltransferase (MTT) assays (n=10). According to the variance homogeneity and normal distribution results, 1-way analysis of variance followed by the Tukey honestly significant difference test or the Welch test and the Games-Howell test were used (α=.05 for all tests). RESULTS: No significant differences were found in the flexural strength values and surface roughness of the specimens containing 1.5% MPC and 1.5% ε-PL compared with those of the control (P>.05). The addition of ε-PL to the PMMA resin alone significantly increased its bactericidal properties (P<.05). Adding both ε-PL and MPC further increased the antibacterial activity of the PMMA resin without increasing protein adhesion more than in the control group. CONCLUSIONS: The incorporation of both ε-PL and MPC into PMMA improved its antibacterial capacity without affecting its mechanical properties and did not increase protein adhesion. Therefore, the novel PMMA fabricated in this study shows promise for dental applications.


Assuntos
Polilisina , Polimetil Metacrilato , Polimetil Metacrilato/farmacologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Metacrilatos , Fosforilcolina/farmacologia , Teste de Materiais , Bases de Dentadura , Propriedades de Superfície
5.
Am J Dent ; 35(6): 291-296, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36508184

RESUMO

PURPOSE: To evaluate the influence of brushing with a specific antiseptic soap solution on the surface (roughness and hardness) and biological properties of a specific hard chairside reline resin. METHODS: The hard chairside reline resin specimens were made and distributed to the following groups according to disinfectant solution: sodium hypochlorite 0.5% (SH), Lifebuoy solution 0.78%; experimental group (LS) and phosphate-buffered saline PBS to be submitted to the brushing cycle for 10 seconds. The roughness and hardness were assessed before and after the cycle. For the biological properties, the colony-forming unit and Alamar Blue assays were performed. For all the properties evaluated the sample size consisted of nine specimens. The data were submitted to two-factor ANOVA (surface properties) and one-way ANOVA (biological properties) and Tukey's post-test with a significance level of 5% (α= 0.05). RESULTS: The Lifebuoy group did not present a statistical difference (P> 0.05) in relation to the other groups for the evaluated surface properties. Furthermore, the Lifebuoy solution showed a statistically significant difference (P> 0.05) in relation to the negative control in the reduction of biofilm on the resin and no significant difference (P> 0.05) was observed when compared to the positive control group. Thus, it was concluded that brushing with the Lifebuoy soap solution did not interfere with the surface properties of the hard chairside reline resin, and was able to reduce the biofilm of C. albicans. CLINICAL SIGNIFICANCE: Disinfectant liquid soap can be used for brushing of relined removable dentures as a simple, low-cost, and effective method for removing the biofilm.


Assuntos
Anti-Infecciosos Locais , Desinfetantes , Sabões , Resinas Acrílicas , Escovação Dentária , Propriedades de Superfície , Candida albicans , Teste de Materiais , Bases de Dentadura
6.
BMC Oral Health ; 22(1): 611, 2022 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-36522725

RESUMO

BACKGROUND: Studies on the antifungal activity, flexural strength, Vickers hardness, and intaglio surface trueness of three-dimensionally printed (3DP) denture bases with microencapsulated phytochemicals with respect to changes in post-polymerization time (PPT) are lacking. METHODS: Specimens of various shapes and dimensions were fabricated with a 3DP denture base resin mixed with 5 wt% phytoncide-filled microcapsules. Each specimen was subjected to different PPT protocols of 5, 10, 20, and 30 min. Specimens without microcapsules with 5-min PPT were used as the negative control group. Cell colonies were counted to evaluate antifungal activity. Three-point bending and Vickers hardness tests were performed to measure the flexural strengths and hardness of the specimens. Fourier-transform infrared spectrometry was used to inspect the degree of conversion (DC). The intaglio surface trueness was measured using root-mean-square estimates calculated by superimposition analysis. A non-parametric Kruskal-Wallis test or one-way analysis of variance was performed (α = 0.05). RESULTS: The specimens with microcapsules and 10-min PPT showed the highest antifungal activity among the tested groups. Compared with the positive control group (5-min PPT), the specimens with PPTs of 10 min or longer showed significantly higher mean flexural strength, higher DC, greater hardness, and better trueness (all, P < 0.05). Except for the difference in antifungal activity, no statistically significant differences were detected between the specimens subjected to 10-, 20-, and 30-min PPT. CONCLUSION: The 3DP denture base filled with microencapsulated phytoncide showed different antifungal activity and physical properties on changing PPT. The 3DP denture base containing phytoncide-filled microcapsules at 5 wt% concentration and subjected to 10-min PPT exhibited sufficient antifungal activity as well as mechanical properties and accuracy within clinical acceptance.


Assuntos
Antifúngicos , Bases de Dentadura , Humanos , Antifúngicos/farmacologia , Polimerização , Cápsulas , Propriedades de Superfície , Impressão Tridimensional , Compostos Fitoquímicos , Teste de Materiais
7.
J Indian Prosthodont Soc ; 22(4): 368-376, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36511071

RESUMO

Aim: Aim of this study was to evaluate the effect of silver nanoparticles incorporated injection molded heat-cured polymethylmethacrylate resin on wettability, anti-fungal effect, flexural strength and colour stability in human saliva. Settings and Design: An In-Vitro study with In -Vivo parameter. Materials and Methods: Rectangular and circular stainless-steel dies were fabricated according to ISO standardization 20795-1:2018 and ADA specification number 12. A total of 144 samples were prepared and divided into 4 groups with thirty-six samples in each group. Each of the 4 groups were subdivided into 3 subgroups based on concentration of silver nanoparticles as 0% in subgroup A, 0.05% in subgroup B and 0.2% in subgroup C. Group 1 samples evaluated wettability, they were assessed at 0, 7, 90 and 180 days after immersing in human saliva using goniometer. Group 2 samples evaluated antifungal effect, they were assessed against Candida albicans in Muller hinton agar plate enriched with 2% glucose. Group 3 samples evaluated flexural strength, they were assessed by using universal testing machine. Group 4 samples evaluated colour stability, they were assessed using UV spectrophotometer at 0, 3 and 7 days after immersing in human saliva. Statistical Analysis Used: One-way ANOVA and Post- Hoc Tukey test were used to evaluate the significant differences in the mean values of the groups. Results: Subgroup C samples with 0.2% Ag nanoparticles had better wettability, maximum antifungal property, highest flexural strength and good colour stability followed by subgroup B and subgroup A samples. Conclusion: Injection molded denture base resin incorporated with 0.2% Ag nanoparticles could be used clinically as a denture base material for completely and partially edentulous patients.


Assuntos
Nanopartículas Metálicas , Polimetil Metacrilato , Humanos , Bases de Dentadura , Prata/farmacologia , Temperatura Alta , Teste de Materiais , Antifúngicos
8.
J Indian Prosthodont Soc ; 22(3): 288-293, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36511060

RESUMO

Aim: The aim of the study was to compare the efficiency of three denture cleansers (Valclean, Polident and Clinsodent) in removal of turmeric stains from flexible denture base resins. Settings and Design: In vitro - comparative study. Materials and Methods: A total of 45 specimens of flexible denture base resins were fabricated and subjected to baseline colour measurements using spectrophotometer. Specimens were stained with turmeric and colour measurements of stained specimens were made. All the stained specimens were divided into three groups (n = 15) for removal of stains with three denture cleansers: Valclean, Polident, Clinsodent and colour measurements of cleansed specimens were made. The colour measurements (ΔE) values obtained were collected and statistical analysis was done. Statistical Analysis Used: One-way ANOVA (Analysis of Variance), Tukey's post hoc test. Results: One way ANOVA test revealed that the mean colour difference of three groups were statistically different with P value < 0.001. A further Tukey post hoc test revealed that the Valclean group had lesser mean scores than Polident and Clinsodent group. Conclusion: It was concluded that Valclean showed statistically significant greater stain removal efficiency than Polident followed by Clinsodent.


Assuntos
Higienizadores de Dentadura , Corantes de Alimentos , Bases de Dentadura , Corantes , Resinas Acrílicas
9.
Sci Rep ; 12(1): 19456, 2022 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-36376540

RESUMO

Colonization of auto-polymerized acrylic resin by pathogenic Candida albicans is a common problem for denture users. In this study, zinc-modified phosphate-based glass was introduced into an auto-polymerized acrylic resin at concentrations of 3, 5, and 7 wt.%. The mechanical or physical properties (flexural strength, elastic modulus, microhardness, and contact angle), surface morphology of the resultant materials, and the antimicrobial effect on C. albicans were investigated. There were no statistical differences in the mechanical properties between the control and the zinc-modified phosphate-based glass samples (p > 0.05); however, the number of C. albicans colony-forming units was significantly lower in the control group (p < 0.05). Scanning electron microscopy revealed that C. albicans tended not to adhere to the zinc-modified-phosphate-based glass samples. Thus, the zinc-modified materials retained the advantageous mechanical properties of unaltered acrylic resins, while simultaneously exhibiting a strong antimicrobial effect in vitro.


Assuntos
Resinas Acrílicas , Anti-Infecciosos , Resinas Acrílicas/farmacologia , Candida albicans , Bases de Dentadura , Propriedades de Superfície , Teste de Materiais , Fosfatos/farmacologia , Zinco/farmacologia
10.
Dent Mater ; 38(12): 2062-2072, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36437128

RESUMO

OBJECTIVES: To investigate the effect of a protective coating on the surface characteristics, flexural properties, cytotoxicity, and microbial adhesion of vat-photopolymerization additive-manufacturing denture base polymers. METHODS: The specimens were additively manufactured using digital light processing (DLP). Specimen surfaces were coated with the same printed resin, and mechanical polishing was used for comparison. Surface topography, arithmetical mean height (Sa), and water contact angle values were measured. Furthermore, flexural strength (FS)/modulus and fractography were evaluated. Also, cytotoxicity was evaluated by an extract test. Finally, an adhesion test was used to investigate the adhesion of mixed oral bacteria to the specimens. RESULTS: The Sa values in the polished (0.26 ± 0.08 µm) and coated (0.38 ± 0.14 µm) groups were significantly lower than in the untreated (2.21 ± 0.42 µm) and control (2.01 ± 0.37 µm) groups. The coating treatment resulted in a higher FS compared to the untreated surface (p = 0.0002). After the coating treatment, no significant differences were found in relative cell viability between the groups (p > 0.05). The quantitative results showed significantly higher bacterial adhesion in the untreated group than in the polished (p = 0.0047) and coated (p < 0.0001) groups. SIGNIFICANCE: The surface characteristics and flexural properties were optimized by the protective coating. Also, the protective coating did not adversely affect cytocompatibility. Moreover, the coating treatment could effectively decrease oral bacteria adhering to the surfaces. Therefore, the protective coating treatment can be a less time-consuming alternative to mechanical polishing as a post-processing procedure for the digital denture.


Assuntos
Resistência à Flexão , Polímeros , Bases de Dentadura , Aderência Bacteriana , Água
11.
J Contemp Dent Pract ; 23(6): 613-617, 2022 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-36259300

RESUMO

AIM: The aim of the current research was to evaluate the tensile bond strength of a soft liner to the denture base resin with different surface management techniques. MATERIALS AND METHODS: Dies made up of stainless steel and having dimensions of 40 × 10 × 10 were used to fabricate polymethyl-methacrylate resinous blocks. To make sure of the regularity of the soft liner in the test, dies made up of stainless steel and having dimensions of 10 × 10 × 3 were fabricated to serve as spacers. These acrylic resinous blocks were allocated to three groups depending upon the particular surface management technique as: group I-Absence of surface treatment (Control), group II-Surface management with methyl methacrylate (MMA) monomer, and group III-Surface management with Phosphoric acid. All the samples underwent thermocycling at 5° centigrade and 55° centigrade in two water baths for 500 cycles at a dwell tenure of 30 seconds in every bath to reproduce the oral circumstances. The samples were then subjected to testing in the universal testing machine for evaluation of the tensile strength. RESULTS: The highest tensile strength was noted in the soft liner with denture base resin that was subjected to treatment with a monomer having a mean score of 1.88 ± 0.11 in pursuit by surface management using phosphoric acid at 1.16 ± 0.90 as well as the control group at 0.94 ± 0.02 in that order. There was a statistically noteworthy disparity amid the three dissimilar surface management techniques with a p-value <0.001. There was a statistically noteworthy differentiation amid group I vs group II as well as group II vs group III with a p-value <0.001. However, there was no statistically significant disparity amid group I vs group III with p-value >0.001. CONCLUSION: The current research arrived at the conclusion that the samples subjected to treatment with MMA monomer exhibited higher and noteworthy bond strength than those attained by additional surface management techniques for soft lining of the denture base resins. CLINICAL SIGNIFICANCE: Soft denture lining materials play a pivotal position in contemporary prosthodontic practice as they possess the ability to restore the health of swollen as well as deformed mucosal tissues. They are comfortable in those individuals who are unable to endure pressure from occlusal forces, like in a situation of residual ridge resorption, sore tissues, and ridges that attain a knife-edge shape. Failing bond causes delamination of the reliner and therefore lack of adaptability of the denture to the oral mucosal tissues. For this reason, superior bonding to the denture base beneath is critical for the clinical triumph of relining agents.


Assuntos
Colagem Dentária , Reembasadores de Dentadura , Humanos , Bases de Dentadura , Aço Inoxidável , Elastômeros de Silicone/química , Teste de Materiais , Propriedades de Superfície , Metilmetacrilato , Água/química , Metacrilatos
12.
Am J Dent ; 35(5): 238-244, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36261403

RESUMO

PURPOSE: To evaluate the influence of brushing with specific antiseptic soap solution on the surface (roughness, hardness, and color stability) and biological properties of a specific heat-polymerized denture base resin. METHODS: 189 denture base acrylic resin specimens (10 mm x 1.2 mm) were made and distributed into three groups: sodium hypochlorite 0.5% (SH), Lifebuoy solution 0.78% (LS) and phosphate-buffered saline (PBS) and were submitted to the brushing cycle for 10 seconds. For each property assessed the sample size was composed of nine specimens. Roughness, hardness, and color stability were assessed before and after the cycle. For the biological properties (biofilm formation and reduction capacity) the colony forming unit and Alamar Blue assays were performed. For this, the specimens were placed separately in a 24-well plate with medium containing C. albicans. The plate was incubated for 48 hours for the formation of mature biofilm. The data were submitted to two-factor ANOVA (roughness and hardness) and one-way ANOVA (color stability and biological properties) and Tukey's post-test (α= 0.05). RESULTS: The Lifebuoy group did not present a statistical difference (P> 0.05) in relation to the other groups for the evaluated surface properties (roughness, hardness, and color stability). Also, from the colony-formation unit and Alamar Blue assays, there was no statistical difference (P> 0.05) between the groups. Regarding biofilm reduction capacity formed on the samples, the results obtained from the count of colony forming units (CFU/mL) showed a reduction of approximately 1.3 logs in the number of CFU/mL in the Lifebuoy group (µ = 4.78 log¹º) compared to the negative control group (µ = 6.02 log¹º) (P< 0.05). When evaluating the cellular metabolism of C. albicans cells, the experimental group did not show any statistical difference compared to controls (P> 0.05). Brushing with Lifebuoy soap solution did not alter the surface properties of the acrylic resin, and reduced the C. albicans biofilm. CLINICAL SIGNIFICANCE: Brushing removable partial or total dentures can be performed using Lifebuoy liquid disinfectant soap, as a simple, low-cost, and effective method for removing biofilm.


Assuntos
Anti-Infecciosos Locais , Desinfetantes , Resinas Acrílicas , Higienizadores de Dentadura/farmacologia , Sabões , Bases de Dentadura , Hipoclorito de Sódio/farmacologia , Candida albicans , Fosfatos
13.
Am J Dent ; 35(5): 251-254, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36261405

RESUMO

PURPOSE: To evaluate two agents for bonding denture bases and teeth manufactured either by stereolithography (SLA) or by the subtractive mixed technique. METHODS: Two types of cylinders [small for the tooth resin and large for the base resin) were designed using CAD software according to the ANSI/ADA 15-2008 (R2013)] specification. For SLA manufacturing, 30 small cylinders were shaped with Denture Teeth resin and 30 large cylinders with Denture Base resin. For the mixed technique, 30 large cylinders were manufactured by SLA with V-print dentbase resin, and 30 small cylinders were milled with a CediTEC DT disk. Half the specimens were bonded with liquid Denture Base resin and half with CediTEC Primer and Adhesive, according to the manufacturers' protocols. Shear bond strength was measured using a universal testing machine. The failure mode was noted for all the specimens. RESULTS: The shear bond strength values were not significantly different between the groups (P> 0.05). Specimens bonded with liquid Denture Base resin displayed cohesive failure (P> 0.05, ײ= 0). Of the specimens bonded with CediTEC Primer and Adhesive, cohesive failures were observed with five specimens manufactured with the SLA technique and one specimen manufactured with the mixed technique (P> 0.05, ײ= 3.33). The Chi-square test results were significant between groups with different bonding agents regardless of the technique used (P< 0.001). Within the limitations of the present study, even if the shear bond strength values were similar, the failure mode analysis suggests that the uncured liquid Denture Base resin may be more effective than the CediTEC Primer and Adhesive for bonding denture bases and teeth manufactured either by SLA or the mixed technique. CLINICAL SIGNIFICANCE: The present study suggests that the uncured liquid resin (Denture Base) used as a bonding agent and the denture base and tooth materials (V-Print and CediTEC DT) manufactured by SLA and the subtractive technique are clinically compatible.


Assuntos
Colagem Dentária , Bases de Dentadura , Resinas Acrílicas/química , Teste de Materiais , Cimentos Dentários , Desenho Assistido por Computador , Resinas Sintéticas , Propriedades de Superfície , Análise do Estresse Dentário
14.
Int J Nanomedicine ; 17: 4639-4658, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36199477

RESUMO

Background: Though acrylic resins possess many useful properties, denture fracture is nevertheless a familiar issue. Objective: This study aimed to determine the effect of low-percent recycled Zirconia nanoparticles as filler on the transverse strength, impact strength, surface hardness, water sorption, and solubility of resin using the sprinkle cold-curing technique. Materials and Methods: Various formulae were prepared and mixed with PMMA (polymer) powder containing varying percentages (0.01%, 0.1%, 0.3%, and 0.5%) of recycled ZrO2NPs to mono-methyl methacrylate (MMA monomer). A 2-hydroxyethyl-methacrylate (HEMA) agent was used to functionalize recycled zirconia (ZrO2) nano-fillers. X-ray diffraction, field emission scanning electron microscopy, high-resolution transmission electron microscopy, energy-dispersive X-ray spectroscopy, and dynamic light scattering were used to characterize the samples. For mechanical tests, standard metallic moulds (according to American Dental Association specification no. 27) were machined for 60 specimens' preparation, 12 for each percent (zero, 0.01%, 0.1%, 0.3%, and 0.5%). A one-way ANOVA test was used to compare the five groups for parametric data, while the Kruskal-Wallis test was employed for nonparametric data. The P 0.05 value was accepted as the significance level. All formulae were tested for cytotoxicity at 24 and 48 hours on WI38 normal lung cell lines. Results: The XRD analysis demonstrated the tetragonal crystallographic structure of the recycled zirconia nanoparticles. Incorporating a low percentage of recycled ZrO2 nanoparticles (0.01%, 0.1%, 0.3%, and 0.5%) improved the tested properties of PMMA to different degrees in a significant and non-significant pattern, while the optimal tested percent was 0.3%. Conclusion: The 0.3% percentage of recycled zirconia nanoparticles maintained and improved the physical and mechanical properties of acrylic resin. Recycled ZrO2/PMMA nanocomposite is a synergistic candidate due to its economic return and clinical application safety.


Assuntos
Bases de Dentadura , Polimetil Metacrilato , Resinas Acrílicas/química , Teste de Materiais , Metacrilatos , Polimetil Metacrilato/química , Pós , Propriedades de Superfície , Água/química , Zircônio
15.
Dent Mater ; 38(12): 1841-1854, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36195470

RESUMO

OBJECTIVE: Three-dimensional (3D) printing is increasingly being utilised in the dental field because of its time-saving potential and cost effectiveness. It enables dental practitioners to eliminate several fabrication steps, achieve higher precision, and attain consistency in complex prosthetic models. The properties of 3D-printed resin materials can be affected by many factors, including the printing orientation (PO) and insufficient post-curing time (CT). This study aimed to investigate the effect of PO and CT on the mechanical and physical properties of a 3D-printed denture base resin (NextDent). METHODS: 3D-printed specimens were fabricated in 0°, 45°, and 90° POs, followed by three CTs (20, 30, and 50 min). The microhardness was tested using a Vickers hardness test, while the flexural property was evaluated using a three-point bending test. Sorption and solubility were measured after the specimens had been stored in an artificial saliva for 42 days, and the degree of conversion during polymerisation was analysed using Fourier Transform Infra-red (FTIR) spectroscopy. RESULTS: The flexural strength of the material significantly increased (p < 0.05) when the printing orientation was changed from 0° to 90°. A similar increase was observed in the hardness, degree of conversion, and water sorption results. In general, no significant difference (p > 0.05) in any of the tested properties was found when the post-curing times were increased from 20 to 50 min. SIGNIFICANCE: The highest physical and mechanical properties of the 3D-printed denture base resin can be obtained by printing vertically (90° angle to the platform base). The minimal post-curing time to achieve ideal results is 30 min, as further curing will have no significant effect on the properties of the material.


Assuntos
Materiais Dentários , Bases de Dentadura , Humanos , Materiais Dentários/química , Teste de Materiais , Odontólogos , Propriedades de Superfície , Papel Profissional , Polimetil Metacrilato/química , Impressão Tridimensional
16.
Int J Mol Sci ; 23(18)2022 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-36142201

RESUMO

Polymethyl methacrylate (PMMA), a well-known polymer of the methacrylate family, is extensively used in biomedicine, particularly in odontological applications including artificial teeth, dentures and denture bases, obturators, provisional or permanent crowns, and so forth. The exceptional PMMA properties, including aesthetics, inexpensiveness, simple manipulation, low density, and adjustable mechanical properties, make it a perfect candidate in the field of dentistry. However, it presents some deficiencies, including weakness regarding hydrolytic degradation, poor fracture toughness, and a lack of antibacterial activity. To further enhance its properties and solve these drawbacks, different approaches can be performed, including the incorporation of nanofillers. In this regard, different types of metallic nanoparticles, metal oxide nanofillers, and carbon-based nanomaterials have been recently integrated into PMMA matrices with the aim to reduce water absorption and improve their performance, namely their thermal and flexural properties. In this review, recent studies regarding the development of PMMA-based nanocomposites for odontology applications are summarized and future perspectives are highlighted.


Assuntos
Nanocompostos , Polimetil Metacrilato , Antibacterianos , Carbono , Bases de Dentadura , Teste de Materiais , Metacrilatos , Óxidos , Polímeros , Propriedades de Superfície , Água
17.
Int J Mol Sci ; 23(18)2022 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-36142344

RESUMO

Polymers remain an integral part of denture fabrication materials, specifically polymethylmetacrylate (PMMA). PMMA has been extensively used, particularly in construction as a denture base material. Nonetheless, various challenges, including microbial threats in the form of candidiasis occurrence, still remain a biological challenge to denture wearers. The present article comprehensively reviews the biomodifications introduced to denture components, in particular denture base material, to improve the overall biological properties, together with physical, mechanical, structural integrity, and optical properties. In addition, fundamental information specifically to PMMA as a conventional denture base material and the causative aetiological microbial agents for biological threat to dentures are explored.


Assuntos
Polímeros , Polimetil Metacrilato , Bases de Dentadura , Dentaduras , Teste de Materiais , Polímeros/química , Polimetil Metacrilato/química , Propriedades de Superfície
18.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 57(9): 927-931, 2022 Sep 09.
Artigo em Chinês | MEDLINE | ID: mdl-36097939

RESUMO

Objective: To compare the accuracy and retention of denture bases fabricated by injection molding, milling, and three-dimensional (3D) printing fabricating, in order to provide some references for clinical practice. Methods: A maxillary edentulous jaw model made was used to duplicated 10 working casts. The casts were numbered and scanned. The wax pattern was designed by digital ways and conventional methods and then the denture bases were fabricated by injection molding, milling, and 3D printing. The tissue surface of experimental denture base was obtained using a dental laboratory scanner. The deviation between the tissue surface of the fabricated denture bases and the working model was evaluated. A digital force gauge was used to measure the traction force. Results: The milling group [(0.076±0.026) mm] was more accurate than the 3D printing group [(0.117±0.041) mm] (P<0.05) and the injection group [(0.120± 0.025) mm] (P<0.05). The accuracy of 3D printing group and that of injection group were not statistically significant (P>0.05). The milling group [(9.55±2.44) N] demonstrated greater retentive force than 3D printing group [(5.19±0.06) N] and injection molding group [(1.52±0.52) N] (P<0.05). Conclusions: The denture base fabricated by milling was more accurate and showed the greatest retentive force than the other groups. And 3D printing group showed better retentive force than the injection molding group. Both digital manufacturing methods can meet the requirements of clinical application.


Assuntos
Bases de Dentadura , Arcada Edêntula , Desenho Assistido por Computador , Humanos , Maxila , Impressão Tridimensional
19.
Br Dent J ; 233(3): 218, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35962099
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