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1.
BMC Oral Health ; 20(1): 193, 2020 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-32641017

RESUMO

OBJECTIVE: To compare the antifungal action of two commercially available denture cleaning agents to that of standard clinical solutions, and determine their effects on the polymethyl methacrylate (PMMA) acrylic resin denture surface. METHODS: Candida albicans growth was analyzed by colony forming assay, and the methyl thiazolyl tetrazolium (MTT) assay was used to evaluate biofilm formation and cell adhesion. The morphology and roughness of PMMA acrylic resin surface was measured by scanning electron microscopy (SEM) images and stylus method. RESULTS: Clene®, Polident® and 3% NaHCO3 solutions showed significantly greater antifungal effects in terms of both inhibiting growth and biofilm formation. In addition, Clene® solution prevented adhesion of C. albicans on cell culture plates compared to filter-sterile tap water, whereas other reagents did not have an inhibitory effect. One-month immersion in the different cleaning reagents significantly inhibited fungal adhesion on the PMMA surface Clene®, Polident® and 3% NaHCO3 showed greater effect compared to PBS and filter-sterile tap water. Finally, none of the cleansing agents significantly affected the morphology and roughness of the PMMA surface. CONCLUSION: Clene®, Polident® and 3% NaHCO3 solutions can inhibit C. albicans growth and biofilm formation to some extent on cell culture plates, and significantly inhibit fungal adhesion on the PMMA surface without affecting surface morphology and roughness.


Assuntos
Biofilmes/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Materiais Dentários/química , Bases de Dentadura , Higienizadores de Dentadura/farmacologia , Polimetil Metacrilato/química , Polimetil Metacrilato/farmacologia , Biofilmes/crescimento & desenvolvimento , Candida albicans/crescimento & desenvolvimento , Humanos , Peróxidos , Propriedades de Superfície
2.
BMC Oral Health ; 20(1): 180, 2020 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-32600325

RESUMO

BACKGROUND: Bonded retainers are widely used as they are esthetically pleasing, easily acceptable, provide greater stability, compliance free and causes no soft tissue irritation and speech problems. Though, fracture and bond failure are their shortcomings. Therefore, the objectives of this study were to evaluate the number of bond failures and type of failure pattern between two types of mandibular canine-canine bonded retainers. METHODS: Total 60 subjects were recruited initially and were assessed for eligibility, out of which 6 were excluded and 2 were lost to follow up. They were randomly divided into two groups. Fiber reinforced composite (FRC) retainers were inserted in group 1 subjects while group 2 subjects received multistranded stainless steel (MSW) retainers. The subjects were recalled after every 3 months over a period of 1 year. Bond failure rate and failure pattern based on adhesive remnant index were evaluated at each visit. The bond failure rate and failure pattern were compared between the two retainers by using Chi-square test. RESULTS: The bond failure rates were 42.94% for FRC retainer and 31.41% for MSW retainer. Hence, total number of bond failures in both retainers were 37.17%. The difference of bond failure between two groups was statistically significant (p = 0.012). Type "0" failure pattern was detected commonly with both types of retainers (p <  0.001). CONCLUSION: Our findings indicate that multistranded stainless steel wire retainer is a superior option to be used for fixed lingual retention in mandibular arch as it exhibited lower bond failure as compared to fiber reinforced composite retainer. Adhesive failure is the most common type of bond failure observed with both types of fixed retainers. TRIAL REGISTRATION: ID NCT03881813 ( https://clinicaltrials.gov/ ); March 19, 2019, retrospective registration.


Assuntos
Colagem Dentária/métodos , Materiais Dentários/química , Desenho de Aparelho Ortodôntico , Contenções Ortodônticas , Adesividade , Adulto , Dente Canino/anatomia & histologia , Esmalte Dentário , Feminino , Humanos , Masculino , Aparelhos Ortodônticos Fixos , Fios Ortodônticos , Estudos Retrospectivos
3.
Niger J Clin Pract ; 23(5): 660-667, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32367873

RESUMO

Aims: The aim of this study is to investigate the color changes of three different traditional composites, one ceramic and two resin-based composites CAD/CAM blocks in different solutions. Methods: The materials used in the study were CAD/CAM block containing lithium disilicate glass ceramic (Ivoclar), Vita Enamic containing resin (VITA), Lava Ultimate Block containing resin (3M ESPE), G-aenial anterior composite (GC,), Filtek™ Ultimate Universal composite (3M ESPE) and Clearfil Majesty Esthetic composite (Kuaray). As colouring solutions, red wine (Buzbaǧ), black tea (Lipton), coffee (Nescafe) and distilled water (EAU distillee) were used. For the preparation of the traditional composite samples to be used in the study, 7 × 7 mm square-shaped plexiglass moulds, 1.2 mm in thickness, were used. The CAD/CAM blocks with ceramic and resin content were cut at the same thickness using a Struers sensitive cutting device. The samples were then randomly separated into grups of 10 and of the 240 samples, groups were separated into 6 different materials and 4 different solutions. The colour measurements of the 240 samples were taken at baseline, 30 days and 120 days with a Lovibond spectrophotometer (Tintometer). Results: A statistically significant difference was determined between the materials in respect of the ΔE values in the 30-day solution groups (P < 0.05). No statistically significant difference was determined in the ΔE values of the different materials in the 30-day and 120-day distilled water groups (P > 0.05). A statistically significant difference was determined between the materials in respect of the ΔE values in the 120-day solution groups (P < 0.05). Conclusion: In respect of discolouration, ceramic blocks are more successful. Resin-based blocks and traditional aesthetic composites showed more discolouration. The dietary habits of the patient should be taken into consideration in the selection of the restorative material.


Assuntos
Cerâmica/química , Materiais Dentários/química , Teste de Materiais/métodos , Cor , Resinas Compostas/química , Desenho Assistido por Computador
4.
Niger J Clin Pract ; 23(5): 720-728, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32367882

RESUMO

Objective: To evaluate the effects of surface coating and 1-year water aging on flexural strength, compressive strength (CS) and surface roughness of fluoride-releasing restorative materials. Materials and Methods: The specimens were prepared from seven materials: GCP Glass Fill (GCP), Amalgomer CR (AHL), Zirconomer (Shofu), Fuji IX GP Capsule (GC), Beautifil II (Shofu), Estelite Σ Quick (Tokuyama), and reliaFIL LC (AHL). The specimens were randomly divided into two groups for each test: surface coated with G-Coat Plus (GC) and uncoated. Each group was subdivided into two groups stored in distilled water at 37°C for 24 h and 1 year before testing (n = 10). The flexural and CS were evaluated according to ISO standards on a universal testing machine. The surface roughness was assessed with AFM. After flexural strength test, a cross-section of the coated specimens was evaluated with SEM. Data were analyzed with one-way analysis of variance, Duncan and independent t-tests (P = 0.05). Results: After 24 h, a significant increase was observed on the flexural and CS of Amalgomer CR, Zirconomer, and Fuji IX GP by coating (P < 0.05). After 1 year, the coating increased the flexural strength of Amalgomer CR and Zirconomer, and CS of GCP Glass Fill (P < 0.05). The coating decreased the surface roughness of GCP Glass Fill, Amalgomer CR, and Zirconomer after 1 year (P < 0.05). The water aging decreased the mechanical properties of glass ionomer-based materials and increased their surface roughness (P < 0.05). Conclusion: The mechanical properties and surface roughness of glass ionomer-based materials were affected by coating and water aging.


Assuntos
Materiais Dentários/química , Fluoretos/química , Força Compressiva , Resistência à Flexão , Teste de Materiais , Propriedades de Superfície , Fatores de Tempo , Água
5.
Niger J Clin Pract ; 23(4): 523-533, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32246660

RESUMO

Objectives: The purpose of this study was to evaluate the effect of the tooth color, ceramic color, and ceramic thickness on the final color parameters of a feldspathic computer-aided design (CAD)/computer-aided manufacturing (CAM) ceramic material. Materials and Methods: Resin specimens (12 × 14 × 4 mm) were prepared from six shades, namely, 0M1S, 1M1S, 2M3S, 3M2S, 4M3S, and 5M3S, to simulate tooth color. Ceramic slices with thicknesses of 0.3, 0.5, 0.7, and 1 mm were sectioned from Vitablocs Mark II (12 × 14 × 18 mm) in 10 shades-OM1C, 1M1C, 1M2C, 2M1C, 2M2C, 2M3C, 3M1C, 3M2C, 3M3C, and 4M2C. An intraoral spectrophotometer was used and three axes of Commission Internationale de l'Eclairage (CIE) LAB color space (CIE L* a* b*) and chroma (C) and hue (H) values were obtained. Results: The a* and b* values showed a decrease with increasing thickness. Generally, C decreased with the increasing ceramic thickness. The effect of ceramic thickness on H changed depending on the block and substructure color. The change of ceramic thickness resulted in changes in the lightness parameter (L*) of the ceramics. Generally, with an increase in the thickness, the L* value increased. The univariate analysis of variance (ANOVA) indicated a significant interaction between ceramic thickness and substructure color (P <. 005) and ceramic thickness and ceramic color (P <. 005). Conclusion: The final color parameters of a feldspathic CAD/CAM block were significantly affected by the changes in the ceramic thickness and substructure color.


Assuntos
Cerâmica/química , Desenho Assistido por Computador , Materiais Dentários/química , Cor
6.
Braz Oral Res ; 34: e020, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32236317

RESUMO

This in vitro study aimed to assess the effects of different pretreatments used to adapt glass-fiber posts cemented to root canals with different resin cements, regarding porosity percentage and bond strength. Twelve bovine incisor roots were prepared with Largo drills. After post space preparation, the specimens were randomized into two types of pretreatment groups (n = 3): water-wet bonding and ethanol-wet bonding. After the post were cemented, the roots were stored in 100% humidity at room temperature for 7 days. The samples were scanned by microcomputed tomography (micro-CT). Images were reconstructed by NRecon software, and CTAn software was used to analyze the porosity percentage (%) at the luting interface. Evaluation of the push-out bond strength was performed by serially cutting the roots, and submitting the slices to testing. Additionally, the resin cement post-gel shrinkage values (%) were measured using the strain-gauge method (n = 10). Data were analyzed by two-way ANOVA, Tukey's test and Student's t test (a = 0.05). The roots prepared with ethanol-wet bonding using RelyX™ U200 had significantly lower porosity in the coronal and apical thirds (p < 0.05). The group prepared with ethanol-wet bonding using RelyX™ ARC presented better bond strength results in the coronal and apical thirds (p < 0.05). RelyX™ ARC (0.97%) produced a higher post-gel shrinkage value than RelyX™ U200 (0.77%). Canals pretreated with ethanol-wet bonding presented better outcomes in regard to porosity percentage and push-out bond strength.


Assuntos
Adesivos Dentinários/farmacologia , Etanol/farmacologia , Técnica para Retentor Intrarradicular , Cimentos de Resina/química , Raiz Dentária/efeitos dos fármacos , Animais , Bovinos , Colagem Dentária , Materiais Dentários/química , Cavidade Pulpar , Vidro , Teste de Materiais , Porosidade , Irrigantes do Canal Radicular/química , Microtomografia por Raio-X
7.
In Vivo ; 34(2): 609-614, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32111760

RESUMO

BACKGROUND/AIM: Tooth extraction is a common procedure in dental clinics. Tooth extraction can destroy gingiva, alveolar bone, periodontal ligaments and cement. If dental sockets are left as extracted, it will result in loss of teeth, as well as voice and aesthetic problems. A natural hydroxyapatite (HA) bioceramic bone graft substitute developed from goose-beak bone particles (GBPs) was used for dentoalveolar reconstruction in a canine model. MATERIALS AND METHODS: Four adult (18-22 months old) male beagle dogs weighing 8.2-9.6 kg were included in the study. Eight alveolar extraction sockets in the four dogs were divided randomly into two groups and a split-mouth design was established; control group, socket filled with commercial synthetic HA; tested group, socket filled with granulated GBP. RESULTS: Micro-CT analysis and hematoxylin and eosin and Masson's trichrome staining of non-decalcified sections were undertaken. Examination revealed that dentoalveolar reconstruction was initiated from the periphery of the host bone, and newly formed bone was well integrated with the GBP. Bone apposition was observed at the edge of the host bone-GBP interface. CONCLUSION: A natural ceramic powder obtained from GBP is suitable for use in dentoalveolar reconstruction in dogs.


Assuntos
Bico , Materiais Biocompatíveis , Regeneração Óssea , Substitutos Ósseos , Materiais Dentários , Gansos , Animais , Bico/química , Materiais Biocompatíveis/administração & dosagem , Materiais Biocompatíveis/química , Substitutos Ósseos/administração & dosagem , Substitutos Ósseos/química , Materiais Dentários/química , Cães , Durapatita/química , Regeneração Tecidual Guiada , Masculino , Osteogênese , Alvéolo Dental/diagnóstico por imagem , Alvéolo Dental/patologia , Microtomografia por Raio-X
8.
Niger J Clin Pract ; 23(3): 304-309, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32134027

RESUMO

Background: Denture hygiene is an important factor to remove dental plaque and discoloration, to provide optimal oral health, and to prevent denture stomatitis. Aim: The purpose of this study was to evaluate the effect of coffee staining and denture cleaner on the color stability of two differently polymerized (heat and microwave) denture acrylic resin in vitro. Materials and Methods: Two commonly used denture base acrylic resins and effervesecnt tablet form denture cleaner were used in this study. Disc-shaped specimens from each acrylic resin were polymerized according to the manufacturer's instructions (n = 7). Color values were recorded before and after immersion in distilled water (I), denture cleaner (II), coffee (III), and coffee + denture cleaner (IV) with a tristimulus colorimeter using CIEDE2000 color difference formula. Two-way analysis of variance (ANOVA) and Fisher's least significant difference tests were used for multiple comparisons at a 95% confidence level (P < 0.05). Surface topography of the acrylic resin denture base specimens before and after immersion were taken under 500 × magnification. Results: The two-way ANOVA revealed significant interactions between denture base resins and solutions (P < 0.001). Immersion in denture cleaner and coffee solution caused significant color changes in acrylic resin denture bases. Conclusion: Heat- and microwave-polymerized acrylic denture base resins can show different color stability. Immersion in coffee and denture cleaner solutions can cause noticeable color changes.


Assuntos
Resinas Acrílicas/química , Café , Materiais Dentários/química , Bases de Dentadura , Higienizadores de Dentadura/efeitos adversos , Temperatura Alta , Micro-Ondas , Descoloração de Dente , Água , Cor , Colorimetria , Humanos , Imersão , Teste de Materiais , Polimerização , Coloração e Rotulagem , Propriedades de Superfície
9.
Niger J Clin Pract ; 23(3): 349-354, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32134034

RESUMO

Objective: To evaluate and compare the fracture resistance and marginal adaptation of Zirconomer and bulk fill posterior restorative material (Surefil SDR) in nonendodontically and endodontically treated teeth. Materials and Methods: The sample consisted of 52 caries-free extracted human premolars which were individually mounted in polyvinyl chloride (PVC) ring filled with acrylic resin up to 1.0 mm below the cementoenamel junction. The teeth were then divided into four groups according to the restorative material used as group I: Zirconomer + Operative only, Group II: Zirconomer + Endodontic treatment, Group III: SDR + Operative, and Group IV: SDR + Endodontic treatment. Fracture strength was tested using a universal testing machine and was expressed in Newtons. The marginal gap was measured at its maximum using a scanning electron microscope and expressed in micrometers. One-way analysis of variance followed by Tukey's post hoc test was used to compare the mean fracture resistance (N) and marginal adaptation (µm) between the four groups. Statistical significance was determined at α = 0.05. Results: Group 3 exhibited significantly highest mean fracture resistance than Group 1 (P < 0.001), Group 2 (P < 0.001), and Group 4 (P < 0.001). Group 4 had significantly higher mean fracture resistance than Group 1 (P = 0.008) and Group 2 (P < 0.001). Group 1 exhibited significantly highest mean marginal gap than Group 3 (P < 0.001) and Group 4 (P < 0.001). Group 2 had a significantly higher mean marginal gap than Group 3 (P < 0.001) and Group 4 (P < 0.001). Conclusion: The fracture resistance and marginal adaptation of Zirconomer are significantly lower than Surefil SDR in both nonendodontically and endodontically treated teeth.


Assuntos
Dente Pré-Molar/química , Adaptação Marginal Dentária , Materiais Dentários/química , Dente não Vital , Restauração Dentária Permanente , Humanos , Teste de Materiais
10.
Life Sci ; 248: 117460, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32092331

RESUMO

AIM: This study determined the optimum gamma irradiation dosage to sterilize sodium hyaluronate (HY), single-walled carbon nanotubes (SWCNT), multi-walled carbon nanotubes (MWCNT) and CNT functionalized with HY (HY-SWCNT and HY-MWCNT), evaluated the structural integrity of the materials and assessed whether sterilized materials kept biological properties without affecting renal function. MAIN METHODS: Materials were submitted to dosages of 100 gγ to 30 Kgγ and plated onto agar mediums for colony forming units (CFUs) counting. Sterilized samples were inoculated with 107Bacillus clausii, submitted again to gamma irradiation, and plated in agar mediums for CFUs counting. Scanning electron microscope was used for structural evaluation of sterilized materials. Tooth sockets of rats were treated with sterilized materials for bone formation assessment and renal function of the animals was analyzed. KEY FINDINGS: The optimum gamma dosage for sterilization was 250 gγ for HY and 2.5 Kgγ for the other materials without meaningful structural changes. Sterilized materials significantly increased bone formation (p < 0.05) and they did not compromise renal function and structure. SIGNIFICANCE: Gamma irradiation efficiently sterilized HY, SWCNT, MWCNT, HY-SWCNT and HY-MWCNT without affecting structural aspects while maintaining their desirable biological properties.


Assuntos
Materiais Dentários/efeitos da radiação , Raios gama , Ácido Hialurônico/efeitos da radiação , Nanotubos de Carbono/efeitos da radiação , Osteogênese/efeitos dos fármacos , Alvéolo Dental/efeitos dos fármacos , Animais , Bacillus clausii/efeitos da radiação , Contagem de Colônia Microbiana , Materiais Dentários/química , Materiais Dentários/farmacologia , Humanos , Ácido Hialurônico/química , Ácido Hialurônico/farmacologia , Testes de Função Renal , Masculino , Dente Molar/cirurgia , Nanotubos de Carbono/química , Nanotubos de Carbono/ultraestrutura , Ratos , Ratos Wistar , Esterilização/métodos , Extração Dentária/métodos , Alvéolo Dental/microbiologia , Alvéolo Dental/fisiologia , Alvéolo Dental/cirurgia , Cicatrização/efeitos dos fármacos
11.
BMC Oral Health ; 20(1): 30, 2020 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-32000753

RESUMO

BACKGROUND: Increased composite roughness enhances bacterial adhesion and discoloration, thus increasing the risk of gingival inflammation and secondary caries. Concerns about detrimental effects of sodium bicarbonate on surface roughness influenced the development of less abrasive powders: a glycine-based powder and an erythritol-based powder, additionally - sodium bicarbonate-based powder of reduced grain size. However, there is limited evidence on effects of these materials on the surface of dental fillings. The aim of the present study was to compare the effects of three air-polishing powders (of a reduced abrasiveness) on surface roughness of microhybrid restorative composite material. MATERIAL AND METHODS: Microhybrid light-cure resin composite samples were placed on 64 plaster cubes and light-cured through polyester strips. Surface roughness was measured using laser confocal microscope (magnification 2160x). The specimens were randomly divided into three groups (n = 20, 20 and 24) and air-polished with: sodium bicarbonate (40 µm), glycine (25 µm) and erythritol (14 µm), respectively. Then surface roughness was remeasured, keeping the same field of observation. Specialized 3D analysis software was used for data processing. Parameters according to ISO 25178: Sa, Sq, Sku, Sp, Sv, Sz, Ssk were used to describe surface roughness. RESULTS: Sa, Sq, Sp, Sv, Sz increased significantly following air polishing. Ssk was significantly higher, whereas Sku was significantly lower in sodium bicarbonate and erythritol groups than before air polishing. Comparison between the three powders revealed that Sa was significantly higher in sodium bicarbonate group than in glycine group. Sku was significantly higher in glycine and erythritol groups than in sodium bicarbonate group. CONCLUSIONS: Sodium bicarbonate has a stronger detrimental effect on composite surface than glycine or erythritol. No advantage of erythritol comparing to glycine could be found.


Assuntos
Resinas Compostas , Materiais Dentários/química , Polimento Dentário/métodos , Bicarbonato de Sódio/química , Pressão do Ar , Resinas Compostas/química , Humanos , Teste de Materiais , Pós , Propriedades de Superfície
12.
BMC Oral Health ; 20(1): 19, 2020 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-31973705

RESUMO

BACKGROUND: The purpose of this research was to investigate the effects of disinfection and three different sterilization methods on the dimensional changes and mechanical properties of three-dimensional (3D) printed surgical guide for implant therapy. The objective was to assess the effects of sterilization procedures in 3D printed drill guide templates with destructive and non-destructive material testing. METHODS: Fifteen identical drill guide templates were produced using a 3D printer. The surgical guides were classified into five groups: three controls, three disinfected (4% Gigasept®, 60 min), three plasma sterilized, three autoclave sterilized (+ 1 bar, 121 °C, 20 min), and three autoclave sterilized (+ 2 bar, 134 °C, 10 min). The templates were digitalized with a Steinbichler SCAN ST 3D scanner. Length was measured under an SZX16 stereomicroscope. A scanning electron microscope was used to study the surface morphology of the drill templates. The hardness, and flexural and compressive strength were measured to assess any changes in the physical characteristics of the material caused by sterilization. The drill guide templates were also examined with a Dage XiDAT 6600 X-ray. During the X-ray examinations, the following parameters were used: 100 kV voltage, 128 AVG averaging, 0.8 W power. One-way analysis of variance (ANOVA) was used to detect the difference between groups. RESULTS: Evaluation of the hardness measurements of the various specimens shows that the hardness of the material was not changed by the plasma sterilization (p = 0.0680), steam sterilization on 121 °C (p = 0.6033) or disinfection process (p = 0.1399). The statistical analysis revealed significant difference in hardness strength of the autoclave sterilized (134 °C) specimens (p = 0.0002). There was no significant difference between the goups regarding the scanning electron microscopic and stereomicroscopic examinations. There was no significant difference regarding the X-ray visibility of the templates to the effect of the disinfection (p = 0.7844), plasma sterilization (p = 0.4091) and steam sterilization on 121 °C (p = 0.9277) and steam sterilization on 131 °C (p = 0.093). The effect of the sterilization was the same in case of both flexural and compressive strength of the material. CONCLUSIONS: Our findings indicate that plasma sterilization and steam sterilization at 121 °C were both suitable for sterilizing the tested 3D printed surgical guides.


Assuntos
Implantação Dentária/instrumentação , Materiais Dentários/química , Desinfecção , Impressão Tridimensional , Vapor , Esterilização/métodos , Cirurgia Assistida por Computador/instrumentação , Desenho Assistido por Computador , Temperatura Alta , Humanos , Teste de Materiais , Projetos Piloto
13.
J Mater Sci Mater Med ; 31(2): 14, 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31965336

RESUMO

The aim of this study was to evaluate volumetric and morphological stability of 3 root-end filling materials in addition to porosity and interface voids, using micro-computed tomography (µCT) in high resolution and a highly accurate approach for image analysis. Following root-end resection and apical preparation, two-rooted maxillary premolars were divided into three groups, according to the filling materials: White MTA Angelus, Biodentine, and IRM. Samples were scanned by µCT at 5 µm after the setting time and at time intervals of 7 and 30 days after immersion in phosphate-buffered saline (PBS). Volumetric and morphological changes besides material porosity and interface voids were evaluated by comparing initial values and those obtained after immersion. Data were analyzed statistically, using ANOVA and t-tests (α = 0.05). All materials showed volumetric stability. Regarding the morphological changes, Biodentine had a significant thickness reduction after storage in PBS when compared with MTA. Biodentine also showed an increase in porosity, as well as in percentage and thickness of voids after 30 days of immersion. In conclusion, µCT in high resolution and an accurate image analysis approach may be used to evaluate morphological changes of endodontic materials. Although Biodentine showed suitable adaptability and lower values of porosity than MTA, after PBS immersion there was a dimensional reduction of this material, besides an increase in porosity and interface voids.


Assuntos
Materiais Dentários/química , Teste de Materiais/métodos , Microtomografia por Raio-X , Restauração Dentária Permanente , Raiz Dentária
14.
Appl Microbiol Biotechnol ; 104(5): 2029-2037, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31940083

RESUMO

Crack propagation is one of the issues associating with dental composites which can significantly affect their performance. Current solutions for preventing and stopping the cracks include maximizing the filler to matrix ratio as well as fiber reinforcing of composites which are not always reliable. The precipitation of calcium carbonate (CaCO3) minerals by the generally recognized as safe (GRAS) bacteria can be seen as a novel approach to address this shortcoming. In the present study, the effect of microbially induced calcium carbonate precipitation (MICP) on filling dental composites' cracks and cavities was studied. In this first step, the capability of different GRAS bacteria to induce CaCO3 precipitation was investigated. In the next step, the capability of potent bacteria to initiate MCIP in solid matrix was evaluated. For this purpose, the CaCO3-bacteria along with necessary nutrients were introduced into different dental composites in two ways, namely, powder and paste form. The light-cured composites were analyzed using optical microscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray (EDS) to identify and characterize the precipitated CaCO3 crystals. It was shown that the incorporation of powder healing compound in two composites resulted in precipitation of CaCO3, while no crystals were formed when a paste form of healing compound was mixed with composites. The results evidently show that MICP can be a feasible alternative to current inefficient approaches to address microcracking issues in dental composites.


Assuntos
Bactérias/metabolismo , Carbonato de Cálcio/química , Materiais Dentários/química , Carbonato de Cálcio/metabolismo , Precipitação Química , Materiais Dentários/metabolismo
15.
Niger J Clin Pract ; 23(1): 110-115, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31929216

RESUMO

Objective: The aim of this study was to compare to effect of phototherapy and surface flattening after immediately bleaching on the shear bond strength to bleached enamel. Methods: Ninety-six human upper incisors were divided into 4 groups (n = 24). Group NB: no bleached, group P: phototherapy with YSGG laser, group F: 0.5 mm surface flattening, group PF: 0.5 mm surface flattening and phototherapy with Er;Cr:YSGG laser. Then, each group was assigned to 2 subgroups according to adhesive mode (n = 12) as; subgroup S (self-etching mode), subgroup T (total-etching mode) which are universal adhesives. All surface conditionings and restorations were performed with composite resin materials immediately after bleaching. Shear bond strength test was performed by using universal testing machine. The surfaces were also evaluated with SEM. The data were statistically analyzed with one-way ANOVA post-hoc Tukey tests. Results: The lowest SBS values were achieved in FS (13.72 ± 2.29) while the highest ones in PT (28.01 ± 6.81). However, the differences were not significant (P > 0.05). All surface conditioning methods provided SBS values similar to the control (P > 0.05). All subgroups of self-etching mode were significantly lower than their total-etching counterparts (P < 0.05). Conclusions: The present study showed that surface removal and phototherapy have a potential clinical application for eliminate to undesirable effect of bleaching treatment. Surface conditioning with either flattening and/or phototherapy may provide clinicians to restore bleached teeth at the same visit with bleaching and reduce chair-time.


Assuntos
Adesivos/farmacologia , Colagem Dentária/métodos , Esmalte Dentário/efeitos dos fármacos , Corrosão Dentária/métodos , Lasers de Estado Sólido/uso terapêutico , Fototerapia , Resistência ao Cisalhamento , Clareamento Dental , Condicionamento Ácido do Dente/métodos , Resinas Compostas/química , Materiais Dentários/química , Humanos , Teste de Materiais , Clareamento Dental/métodos
16.
J Appl Oral Sci ; 28: e20190042, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31778443

RESUMO

INTRODUCTION: Gap formation of composite resin restorations is a serious shortcoming in clinical practice. Polymerization shrinkage stress exceeds the tooth-restoration bond strength, and it causes bacterial infiltration within gaps between cavity walls and the restorative material. Thus, an intermediate liner application with a low elastic modulus has been advised to minimize polymerization shrinkage as well as gap formation. OBJECTIVE: The purpose of this in vitro study was to assess gap formation volume in premolars restored with different bulk-fill composites, with and without a resin-modified glass-ionomer cement (RMGIC) liner, using x-ray micro-computed tomography (micro-CT). METHODOLOGY: Sixty extracted human maxillary premolars were divided into six groups according to bucco-palatal dimensions (n=10). Standardized Class II mesio-occluso-distal cavities were prepared. G-Premio Bond (GC Corp., Japan) was applied in the selective-etch mode. Teeth were restored with high-viscosity (Filtek Bulk Fill, 3M ESPE, USA)-FB, sonic-activated (SonicFill 2, Kerr, USA)-SF and low viscosity (Estelite Bulk Fill Flow, Tokuyama, Japan)-EB bulk-fill composites, with and without a liner (Ionoseal, Voco GmbH, Germany)-L. The specimens were subjected to 10,000 thermocycles (5-55°C) and 50,000 simulated chewing cycles (100 N). Gap formation based on the volume of black spaces at the tooth-restoration interface was quantified in mm3 using micro-computed tomography (SkyScan, Belgium), and analyses were performed. Data were analyzed using repeated-measures ANOVA and the Bonferroni correction test (p < 0.05). RESULTS: The gap volume of all tested bulk-fill composites demonstrated that Group SF (1.581±0.773) had significantly higher values than Group EB (0.717±0.679). Regarding the use of a liner, a significant reduction in gap formation volume was observed only in Group SFL (0.927±0.630) compared with Group SF (1.581±0.773). CONCLUSION: It can be concluded that different types of bulk-fill composite resins affected gap formation volume. Low-viscosity bulk-fill composites exhibited better adaptation to cavity walls and less gap formation than did sonic-activated bulk-fill composites. The use of an RMGIC liner produced a significant reduction in gap formation volume for sonic-activated bulk-fill composites.


Assuntos
Resinas Compostas/química , Preparo da Cavidade Dentária/métodos , Materiais Dentários/química , Restauração Dentária Permanente/métodos , Imageamento Tridimensional/métodos , Polimerização , Análise do Estresse Dentário , Humanos , Técnicas In Vitro , Teste de Materiais , Cimentos de Resina , Microtomografia por Raio-X
17.
Microsc Res Tech ; 83(2): 202-207, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31729109

RESUMO

The objective of this study was to examine the effects of extrinsic or intrinsic acids on nanofilled and bulk fill resin materials in vitro. A total of 90 disks were prepared using dental restorative material (Filtek Z350XT, GrandioSO, Filtek Bulk Fill, X-tra fil). Thirty disks of each material were sub-divided into three groups (n = 10) that were immersed for 7 days in deionized water (DW), 5% citric acid (CA-pH 2.1), or 0.1% hydrochloric acid (HCl-pH = 1.2). Surface hardness and roughness (stylus profilometer by Ra parameter) analysis were performed before and after immersion. Morphological changes were evaluated by scanning electron microscopy. The data were analyzed by two-way ANOVA and Tukey's test (α = 0.05). All tested materials did not show significant differences in the effects of the DW, CA, or HCl solutions on surface roughness (p = .368). Likewise, the hardness loss was not affected by the solutions tested (p = .646), but there was a difference in the resin type (p = .002). Filtek Bulk Fill resin hardness was less affected, while Filtek Z350XT and GrandioSO presented the most hardness loss after 7 days of solution immersion. In terms of this experimental study, the results demonstrate the effectiveness of the mechanical properties (roughness and hardness surface) of nanofilled and bulk fill resin materials to resist erosion from extrinsic and intrinsic acids, therefore being potential candidates for dental applications.


Assuntos
Ácidos/química , Resinas Compostas/análise , Materiais Dentários/análise , Teste de Materiais , Resinas Compostas/química , Materiais Dentários/química , Dureza , Microscopia Eletrônica de Varredura , Propriedades de Superfície
18.
Mater Sci Eng C Mater Biol Appl ; 106: 110167, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31753414

RESUMO

New inventions and innovations in the field of dentistry have potential applications to satisfy the patient's demand. In prosthodontics, a dental prosthesis plays a major role in improving the quality of oral health care. Currently, the trends have shifted towards the implants and implant-supported prosthesis for the replacement of missing teeth. Conventional dentures are patient's preference mainly due to financial constraints. In an attempt to find solutions to current problems, we have come across new materials zirconium, titanium and new inventions like flexible dentures, fenestrated dentures, and CAD/CAM fabricated dentures. Using the progress of past five years in the field of prosthodontics, this comprehensive review focuses on denture base materials, denture liners, removable partial dentures, fixed prosthesis such as crown and bridge materials, implant-supported a fixed denture, artificial teeth materials, impression materials, and ingenious alternatives to conventional dentures. This article also sheds some light on the current promising researches and gives insight into the problems that can be the focus of future researches.


Assuntos
Prótese Dentária Fixada por Implante , Coroas , Materiais Dentários/química , Planejamento de Prótese Dentária , Prótese Parcial Removível , Humanos , Zircônio/química
19.
Technol Health Care ; 28(1): 35-44, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31104033

RESUMO

BACKGROUND: Clinicians routinely encounter the endodontically treated teeth with wide flared canals and mineral trioxide aggregate (MTA) repair on the canal wall. OBJECTIVE: To assess the effect of customized glass reinforced composite (FRC) post and reshaped root canal along with different acid etching protocol of MTA surface on push-out bond strength (PBS) in flared, MTA repaired root canal. METHODS: Ninety recently extracted single-rooted premolar teeth were sequentially subjected to root canal obturation, post space preparation, flaring, and MTA application. The samples were randomly divided into 3 groups of control (no relining or reshaping), customized FRC post by relining with self-adhesive resin cement and reshaping the canal with flowable composite. Each group was subdivided into 3 subgroups (n= 10) as no surface treatment, 37% H3PO4 and 19% EDTA etching of MTA surface. Teeth samples cemented with FRC post were sectioned into 2 mm and push-out testing. RESULTS: Control group had the lowest PBS at 1.988 N. The PBS values for the groups with customized post relining were 8.489 N, 8.888 N and 7.911 N for control, H3PO4 etch and EDTA etch. The corresponding PBS values for root canal reshaping were 7.323 N, 8.318 N and 7.785 N. CONCLUSIONS: Customized FRC post with 37% H3PO4 etching is advised for the flared and MTA repaired root canals.


Assuntos
Compostos de Alumínio/química , Compostos de Cálcio/química , Materiais Dentários/química , Vidro/química , Óxidos/química , Preparo de Canal Radicular/métodos , Silicatos/química , Combinação de Medicamentos , Humanos
20.
Clin Oral Investig ; 24(5): 1695-1700, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31338631

RESUMO

OBJECTIVE: To evaluate the artifact expression of a new material-polylactic acid (PLA)/hydroxyapatite (HA)/graphene oxide (GO) nanocomposite-and compare it with that of commonly used dental materials, using cone-beam computed tomography. MATERIALS AND METHODS: Cylinders of amalgam alloy, metal alloy, titanium, gutta-percha, and PLA/HA/GO were individually placed in the center of an acrylic phantom. Three images of each phantom + cylinder set were acquired using a Picasso Trio unit (Vatech, Hwaseong, South Korea) set at 90 kVp, 3.7 mA, 0.2 mm3 voxel size, and 12 × 8.5 cm FOV. Three images of a control group (sound phantom) were also obtained. Eight ROIs were established in each image to evaluate the standard deviation (S.D.) of gray values in the ImageJ Software. The Kruskal-Wallis test with the Student-Newman-Keuls post hoc was employed, considering a significance level of 5%. RESULTS: There were no significant differences in S.D. between the control and PLA/HA/GO images (p = 0.712). Both control and PLA/HA/GO showed fewer image artifacts than the other materials (p < 0.05). The images of the amalgam alloy did not differ from the metal alloy images (p = 0.691), showing more artifacts than the gutta-percha (p = 0.028) and titanium (p = 0.051). CONCLUSIONS: The PLA/HA/GO produced fewer artifacts and a better-quality image than the other tested materials. CLINICAL RELEVANCE: The PLA/HA/GO has physical and biological properties similar to those of dental materials. Since it has produced fewer image artifacts, this new nanocomposite may be employed in the near future, enhancing the diagnosis in CBCT.


Assuntos
Materiais Dentários/química , Durapatita/química , Grafite/química , Nanocompostos/química , Poliésteres/química , Artefatos , Tomografia Computadorizada de Feixe Cônico , Imagens de Fantasmas
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