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1.
São Paulo; s.n; 20210219. 78 p.
Tesis en Portugués | LILACS, BBO - Odontología | ID: biblio-1147715

RESUMEN

A resina acrílica é usada em larga escala nos mais diversos setores inclusive na odontologia. Apesar dessa difusão, esse material sofre um problema sério frente a adesão de microrganismos em sua superfície. Visando isso, o presente trabalho elaborou um biomaterial baseado na incorporação do biocida Poli (cloreto de dialildimetilamônio) (PDADMAC) na massa de resinas acrílicas auto e termopolimerizável, avaliou suas propriedades antifúngicas e citotoxicidade. O PDADMAC foi incorporado nas resinas acrílicas e sua atividade antifúngica foi testada frente aos fungos Candida albicans (ATCC 10231) e Aspergillus niger (ATCC 16404) seguindo os protocolos padrão G21-15 e E2149-13. Além disso, cepas isoladas da mucosa oral de pacientes sem doenças sistêmicas foram identificadas e a partir disso foram realizados os estudos de protease e de potencial antifúngico frente a essas cepas. Foram realizados também os testes de citotoxidade utilizando o ensaio de redução de MTT em células-tronco de polpa dentária cultivadas em contato com meio de cultura condicionado pelas resinas. Os resultados demostraram que ambas as resinas com PDADMAC exibiram eficácia significativa contra Candida albicans. Já com relação ao fungo Aspergillus niger, ficou evidente que esse material possui apenas eficácia fungistática. Com relação às cepas isoladas da mucosa oral de pacientes sem doenças sistêmicas, foi observado que a Candida albicans foi a mais prevalente e que independente da produção de protease produzidas por essas cepas as resinas acrescidas de PDADMAC são eficazes. Nos exames de citotoxidade a adição do biocida nas resinas não afetou a viabilidade celular quando comparada às células cultivadas em condições ideais. Portanto, conclui-se que a incorporação de PDADMAC nas resinas acrílicas foi determinante para alcançar o efeito antifúngico desejado, mantendo a biocompatibilidade. Este estudo encontrou resultados promissores para o uso futuro deste biocida em materiais odontológicos.


Asunto(s)
Resinas Acrílicas , Materiales Dentales , Antifúngicos
2.
Artículo en Inglés | MEDLINE | ID: mdl-33528447

RESUMEN

This study compares the mechanical strengths of bulk-fill composite resin and amalgam material to investigate the stress distribution and capacity to mitigate stress of restored Class I and Class II teeth under chewing loads, using finite element analysis. A 3D model of a human mandibular first molar and four Class I (C1) and Class II (C2) caries, including 95-degree cavity-margin angles, were created. Different material combinations were simulated: model C1-A and C2-A, with an amalgam material; and model C1-C and C2-C, with a bulk-fill composite resin. Solid 3D elements with four grid points were employed for modeling the tooth. A vertical occlusal load of 600 N was applied, and nodal displacements on the bottom cutting surfaces were constrained in all directions. All materials were assumed to be isotropic and elastic, and a static linear analysis was performed. The highest maximum principal stress was observed in C2-C, followed by C1-C, C2-A, and C1-A, respectively. The maximum principal stress load on the lingual cusp was recorded at the junction of the lingual margin (C1-C and C2-C), and stress was recorded on the line of restoration and enamel (C1-A and C2-A). Restoration materials and cavity preparations influence the stress distribution at the restoration-tooth interface and, consequently, the measured bond strength.


Asunto(s)
Materiales Dentales , Restauración Dental Permanente , Resinas Compuestas , Análisis del Estrés Dental , Humanos , Ensayo de Materiales , Estrés Mecánico
3.
Int J Prosthodont ; 34(1): 47-53, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33570519

RESUMEN

PURPOSE: To investigate the impact of high-speed sintering and artificial aging on the fracture load of three-unit zirconia fixed dental prostheses (FDPs). MATERIALS AND METHODS: Three-unit FDPs manufactured from 3Y-TZP (Ceramill Zolid, Amann Girrbach) and 4Y-TZP (Ceramill Zolid HT+, Amann Girrbach; N = 128, n = 64/group) were sintered at 1,580°C (high-speed sintering) or at 1,450°C (control group; n = 32/subgroup). Specimens were bonded to steel abutment models using Multilink Automix (Ivoclar Vivadent), and fracture load was examined without (n = 16/subgroup) and with artificial aging (6,000 thermocycles [5°C/55°C] and 1,200,000 chewing cycles [50 N]; n = 16/subgroup). Univariate analysis of variance, unpaired t test, and Weibull modulus were computed (P < .05). RESULTS: Sintering protocol (P = .944), artificial aging (P = .630), and zirconia material (P = .445) did not show an influence on the fracture load of three-unit FDPs. High-speed sintering led to superior Weibull modulus results for artificially aged 4Y-TZP specimens, while all other groups showed values in the same range. CONCLUSION: The present study shows promising results for the novel high-speed sintering protocol, as it led to comparable fracture load and similar, or even superior, Weibull modulus results compared to the control group. The 4Y-TZP material presented fracture load results similar to the tried-and-tested 3Y-TZP. Artificial aging did not influence zirconia's resistance to fracture for either 3Y-TZP or 4Y-TZP.


Asunto(s)
Prótesis Dental , Circonio , Materiales Dentales , Porcelana Dental , Análisis del Estrés Dental , Ensayo de Materiales
4.
Monogr Oral Sci ; 29: 155-194, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33427213

RESUMEN

Biofilm formation depends on many factors, one of them being the surface (substrate) on which the biofilm is formed, and dental restorative materials are such substrates. Biofilms play a crucial role for caries formation and inflammation of gingival, periodontal, or mucosal tissues next to restorations. Even general health problems such as systemic infections in immunocompromised patients may result from biofilms on dental materials (e.g., on dentures). Furthermore, biofilms may change material or surface properties. Biofilms on restorative materials have been investigated by several in vitro, in situ, and in vivo methods measuring a large number of different endpoints. Basically, datasets obtained from different methodological approaches are most suitable for final assessments. While surface properties like wettability or surface free energy (SFE) influence biofilm formation to a certain extent, the most relevant surface properties are material roughness followed by surface chemistry. The pellicle, which is formed rapidly on restorations after in vivo exposure, masks or levels off the influence of surface properties like wettability or SFE on biofilm formation. The prevention of biofilm formation is mainly based on general oral hygiene regimens. Furthermore, optimal polishing of restorative materials is instrumental. Several antimicrobial substances have been incorporated into restorative materials, which act by being released or as surface repellents. However, the optimal biofilm-preventive restorative material has not been found so far. New approaches in this context should aim at: (1) better understanding the role of the biofilm matrix (extracellular polymeric substance), and (2) implementing ecology-based approaches for the modification of dysbiotic disease-associated biofilms.


Asunto(s)
Adhesión Bacteriana , Matriz Extracelular de Sustancias Poliméricas , Biopelículas , Materiales Dentales , Película Dental , Humanos
6.
Quintessence Int ; 0(0): 0, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33491388

RESUMEN

Objectives: This systematic review aimed to evaluate the clinical and radiographic outcomes of coronal and partial pulpotomies in mature permanent molars with cariously exposed vital pulp. Method and materials: The protocol of the current review was registered in the PROSPERO database (CRD 42020190785). Articles published between January 1980 and June 2020 were searched in eight different online databases and six textbooks according to PRISMA guidelines. Eleven studies were included in the analysis of 1-year success rates, whereas five studies were included in the analyses of 2-year and > 2-year success rates for coronal pulpotomy. Two studies were included in the analyses of the 1-year and 2-year success rates for partial pulpotomy. The clinical and radiographic success rates were estimated using the DerSimonian-Laird random effect method. The risks of bias were evaluated using Cochrane RoB 2, ROBINS-I, and Newcastle-Ottawa scale assessment tools. Evidence levels were determined using the Oxford Centre for Evidence-Based Medicine (OCEBM) recommendation tool. The success rates using different pulp capping medicaments and restorative materials were analyzed using meta-regression analysis. Results: The clinical and radiographic success rates of coronal pulpotomy ranged between 92.2% and 99.4%, whilst for partial pulpotomy, the success rates ranged between 78.2% and 80.6%. Different pulp capping medicaments and restorative materials showed no significant effect on the success rates of coronal pulpotomy, but the former significantly (P < .05) affected the success rates of partial pulpotomy. Conclusion: Coronal and partial pulpotomies demonstrated a high success rate in treating cariously exposed vital pulp of mature permanent molars. Further well-designed studies with longer follow-up periods are required to validate these findings.


Asunto(s)
Caries Dental , Pulpotomía , Materiales Dentales , Recubrimiento de la Pulpa Dental , Humanos , Diente Molar/diagnóstico por imagen , Diente Molar/cirugía , Diente Primario , Resultado del Tratamiento
7.
Rev. cuba. estomatol ; 57(4): e3016, Oct.-Dec. 2020. graf
Artículo en Inglés | LILACS, CUMED | ID: biblio-1144446

RESUMEN

ABSTRACT Introduction: The passivity of prosthetic components is one of the most important prerequisites in oral implant rehabilitation for maintenance of osseointegration. Objective: Thus, the present study analyzed in vitro the accuracy of different molding techniques in prosthetic rehabilitation on angled implants installed in an anatomical model of a metallic edentulous maxilla. Methods: Laboratory experiment study. A reference metal model of an edentulous maxilla was used. A metal framework was used for the misadaptation assessment. Three groups (n= 10) were compared and impressions were made with vinyl-polysiloxane and casts were obtained with type IV stone: (1) Impression with a metallic open-tray without splinted transfers; (2) Impression with a metallic open-tray and metal splinted transfers; (3) Impression with a multifunctional guide and metal splinted transfers. Misadaptation was assessed with the aid of a stereomicroscope and measuring software. Data were submitted to ANOVA with Welch correction and the Games-Howell post-hoc test with the significance set at 5 percent. Results: Misadaptation (µm) was 110,23 ± 30,94, 37,53 ± 3,92, and 37,69 ± 2,79 for the the groups. Statistically significant differences between impression with a metallic open-tray with and without splinted transfers were observed (p < 0,001). No significant differences between the other types of impression. Conclusions: Impression with a metallic open-tray without splinted transfers and with a multifunctional guide splinted with metal transfers were the most precise methods resulting in higher accuracy in transferred implants(AU)


RESUMEN Introducción: La pasividad de los componentes protésicos es uno de los prerrequisitos más importantes para el mantenimiento de la osteointegración en la rehabilitación oral sobre implantes. Objetivo: Evaluar in vitro la precisión de diferentes técnicas de impresión en rehabilitación sobre implantes inclinados instalados en un modelo anatómico de un maxilar metálico desdentado. Métodos: Estudio de laboratorio de tipo experimental. Se utilizó un modelo metálico de referencia de un maxilar desdentado. Fue utilizada una barra metálica para la evaluación de la desadaptación. Se compararon tres grupos (n = 10), se realizaron impresiones con polivinilsiloxano y se obtuvieron modelos con yeso piedra tipo IV: (1) impresión con una cubeta metálica abierta sin unión de los transferentes; (2) impresión con una cubeta metálica abierta y unión de los transferentes con cilindros metálicos; (3) impresión con una guía multifuncional y unión de los transferentes con cilindros metálicos. La desadaptación se evaluó con la ayuda de un microscopio estereoscópico y un software de medición. Los datos se enviaron a ANOVA con la corrección de Welch y la prueba post-hoc de Games-Howell con la significación establecida en 5 por ciento. Resultados: La desadaptación (µm) fue de 110,23 ± 30,94; 37,53 ± 3,92 y 37,69 ± 2,79 para los grupos, respectivamente. Se observaron diferencias estadísticamente significativas entre la impresión con cubeta abierta metálica con y sin unión de los transferentes (p <0,001). No hubo diferencias significativas entre los otros tipos de impresiones. Conclusiones: La impresión con cubeta abierta metálica sin unión de los transferentes y con una guía multifuncional con unión de los transferentes con cilindros metálicos fueron los métodos más precisos que dieron como resultado una mayor precisión en la transferencia de la posición de los implantes(AU)


Asunto(s)
Humanos , Implantación Dental/métodos , Materiales de Impresión Dental/efectos adversos , Materiales Dentales/uso terapéutico
8.
Braz Dent J ; 31(5): 523-531, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33146337

RESUMEN

Thiourethane additives have been shown to improve properties in several dental polymer applications. The aim of this study was to verify the effect of the addition of thiourethane oligomers and acrylamide or isobornyl-based plasticizers on the physical properties of the denture base acrylic resin polymerized with microwaves. Thiourethane oligomer (TU) was synthetized and added to microwaved acrylic resin in proportions varying between 3 and 14 wt%. Separate experimental groups included the addition of dimethyl acrylamide (DMAM) and isobornyl methacrylate as plasticizers, at concentrations varying from 5 to 20 wt%. Samples were polymerized using microwave energy at 500 Watts for 3 min, deflasked at room temperature, stored in water at 37 °C for 24 h, and evaluated for: linear dimensional change, gloss, Knoop hardness, surface roughness, impact strength, yield strength, elastic modulus, toughness, yield strength, viscosity, glass transition temperature and network heterogeneity, and water sorption/solubility. Data were analyzed with ANOVA/Tukey's post-hoc test (a=5%). The addition of TU led to properties that were similar or worse than the materials to which it was not added, except for dimensional stability. The impact on properties was statistically significant for all materials above 20% addition of TU. The addition of DMAM at 5 wt% or isobornyl methacrylate at 10 wt% improved yield strength and modulus, but increased water sorption and solubility. Except for dimensional stability, the addition of thiourethane oligomers to acrylic denture base materials compromised most tested properties. The use of DMAM and isobornyl methacrylate improved properties for selected compositions.


Asunto(s)
Bases para Dentadura , Microondas , Materiales Dentales , Ensayo de Materiales , Polimerizacion , Polimetil Metacrilato , Propiedades de Superficie
9.
J Adhes Dent ; 22(5): 515-522, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33073782

RESUMEN

PURPOSE: To evaluate the biocompatibility in rat subcutaneous tissue of conventional orthodontic cements, Riva (R) and Meron (M), modified by the addition of ethanolic extract of red propolis (EERP), at different concentrations and time intervals. MATERIALS AND METHODS: One hundred eight male adult Wistar rats were used, distributed in nine groups of cements with added EERP at the concentrations used (C-control, MC, M10, M25, M50, RC, R10, R25, and R50). The rats were sacrificed after 3 time intervals (7, 15, and 30 days). Histological and immunohistochemical analyses were performed. The findings were statistically analyzed using the Kruskal-Wallis test followed by Dunn's test (p < 0.05). RESULTS: The highest concentrations led to a higher level of inflammation at the initial times (p < 0.05), but without differences after 30 days. In terms of collagen, there was less collagenization at the initial times in comparison with the control group C. However, over time, the addition of propolis resulted in healing compatible with that of group C. The level of CD68 immunostaining was statistically significantly higher in the groups with the highest concentrations (R50 and M50) (p = 0.001). CONCLUSION: Orthodontic cements with the addition of EERP were found to be biocompatible in rat subcutaneous tissue. Riva cement with the addition of 50% EERP showed the highest tissue inflammation, but with satisfactory tissue repair.


Asunto(s)
Própolis , Animales , Cementos Dentales , Materiales Dentales , Masculino , Ratas , Ratas Wistar , Tejido Subcutáneo
10.
J Adhes Dent ; 22(5): 540-544, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33073785
11.
Pediatr Dent ; 42(5): 392-398, 2020 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-33087225

RESUMEN

Purpose: he purpose of this study was to evaluate in vitro the effect of 5.25 percent sodium hypochlorite (NaOCl) on the bond strength of resin sealant to hypomineralized enamel. Methods: Sound (S) and hypomineralized (H) enamel specimens were subjected to three different treatments: (1) etch only (E); (2) 5.25 percent NaOCl treatment (60 seconds) after (Post) etching; and (3) 5.25 percent NaOCl treatment (60 seconds) before (Pre) etching. A sealant rod was bonded for microshear bond strength (µSBS) testing. DIAGNOdent™ and spectrophotometry were used to detect changes in surface organic content and verify the amount of organic material removed. Results: Ninety S and 90 H specimens were randomly grouped into SE, SPost, SPre, HE, HPost, HPre groups. The average µSBS of hypomineralized enamel in etch only (HE) and NaOCl pre-etch (HPre) were significantly lower (9.2 MPa). NaOCl after etching significantly increased the µSBS of hypominineralized enamel (HPost) to 14.5 MPa, similar to sound enamel. DIAGNOdent™ readings were significantly lower in NaOCl Post versus E and NaOCl Pre, suggesting lower surface organic content. Spectrophotometry confirmed that NaOCI significantly removed more organic material in hypomineralized enamel. Conclusion: Applying 5.25 percent sodium hypochlorite for 60 seconds after etching (32 percent phosphoric acid) increased the bond strength of resin sealant to hypomineralized enamel comparable to that of sound enamel, as a result of surface organic content removal.


Asunto(s)
Materiales Dentales , Hipoclorito de Sodio , Esmalte Dental , Humanos
12.
Int J Esthet Dent ; 15(4): 428-439, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33089258

RESUMEN

OBJECTIVE: The combination of partial edentulism and a worn anterior tooth in the esthetic zone can be a challenge for the dentist. This clinical situation requires extensive knowledge of soft and hard tissue management, surgical planning and execution for implant therapy, and conservative tooth preparation with ideal bonding protocols for the tooth-supported prosthesis. Moreover, an optimal selection of the final restorative materials is imperative to manage occlusal forces and fulfill the patient's esthetic demands. MATERIALS AND METHODS: The patient presented with partial edentulism on site 11, a worn incisal edge, and facial defects on tooth 21. Minimally invasive implant therapy for site 11 was performed with a papilla-sparing flap design that only included the edentulous site, and the soft tissue contouring was started for an immediate provisional restoration. A suturing technique was executed that aimed at maintaining an interproximal papilla. Conservative veneer preparation was performed on tooth 21 in order to bond the restoration to the enamel structure. Final restorations included a custom abutment with a lithium disilicate fused to zirconia crown for the implant on site 11 and a lithium disilicate veneer on tooth 21. CONCLUSIONS: A well-planned single implant and a ceramic veneer restoration was able to fulfill the patient's esthetic expectations. The selection of materials for the final restoration was crucial to manage the occlusal forces and to mimic the shade and shape of the adjacent teeth.


Asunto(s)
Implantes Dentales , Estética Dental , Coronas , Materiales Dentales , Estética , Humanos
13.
Shanghai Kou Qiang Yi Xue ; 29(4): 375-379, 2020 Aug.
Artículo en Chino | MEDLINE | ID: mdl-33089285

RESUMEN

PURPOSE: To investigate the effect of commonly used subgingival wedge-shaped defect filling materials on the formation of Porphyromonas gingivalis (P.gingivalis) biofilm. METHODS: Subgingival class V cavities were prepared on the buccal surfaces of 48 extracted premolars. After that, the premolars were randomly divided into 3 groups (A, B and C) with 16 in each group. After filling and polishing with universal nano fluid resin, universal nano solid resin and glass ionomer cement individually, Isomet 4000 precision cutting machine was used to make specimens containing all the filling materials (mesiodistal distance: 5 mm, occlusal-gingival distance: 3 mm, buccolingual distance: 2 mm). All the specimens were placed in P.gingivalis bacterial solution for 24 hours to form P.gingivalis biofilm. Then the attachment amount of P.gingivalis was observed by crystal violet staining. Confocal laser scanning microscopy (CLSM) was used to observe the P.gingivalis biofilm. SPSS 22.0 software package was used for Kruskal-Wallis rank sum test. RESULTS: The results of crystal violet staining showed that the amount of P.gingivalis adhered to the glass ionomer cement filling surface was significantly less than that of other groups(P<0.05). CLSM scan showed no significant difference in proportion of viable bacteria and biofilm thickness among three groups (P>0.05). P.gingivalis biofilm in glass ionomer cement group was sparse, showing small clumps, and did not aggregate into pieces. On the surface of universal nano solid resin, P.gingivalis biofilm was in large pieces with a three-dimensional structure. CONCLUSIONS: Compared with the universal nano solid/fluid resin, the surface of glass ionomer cement is not conducive to the formation of P.gingivalis biofilm. Therefore, from the perspective of periodontal health, glass ionomer cement is suitable for filling treatment of subgingival wedge-shaped defects.


Asunto(s)
Materiales Dentales , Porphyromonas gingivalis , Biopelículas , Cementos de Ionómero Vitreo , Microscopía Confocal
14.
J Contemp Dent Pract ; 21(6): 691-695, 2020 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33025941

RESUMEN

AIM: The longevity of restorative materials depends on the resistance to masticatory forces. The present study was undertaken to evaluate the mechanical and microleakage properties of Cention-N with glass ionomer cement (GIC) and composite restorative materials. MATERIALS AND METHODS: A total of 45 specimen blocks were prepared with 15 samples of each type of restorative material, namely Cention-N, GIC, and hybrid composite. Samples were subjected to load at crosshead speed of 0.75 ± 0.25 mm/min till the fracture of sample. Class V cavities were prepared on the buccal surface of orthodontically extracted premolars followed by restoration of each test material. All the surfaces of the tooth were coated with clear nail varnish except 1 mm around the margins of the restorations. These samples were immersed in 0.5% basic fuchsine dye and longitudinally sectioned and observed under stereomicroscope to check microleakage. The obtained data were statistically evaluated. RESULTS: We found the highest mean compressive and flexural strength for hybrid composite followed by Cention-N and least for GIC which is statistically significant (p < 0.001). CONCLUSION: Mean microleakage was least for Cention-N. Cention-N is a newer restorative material having higher mechanical properties with lesser microleakage. CLINICAL SIGNIFICANCE: Cention-N is a newer restorative material having promising properties. This material can be used as an alternative restorative material.


Asunto(s)
Filtración Dental , Resinas Compuestas , Materiales Dentales , Restauración Dental Permanente , Cementos de Ionómero Vitreo , Humanos
15.
Swiss Dent J ; 130(10): 785-790, 2020 10 12.
Artículo en Alemán | MEDLINE | ID: mdl-33044805

RESUMEN

Minimally invasive dentistry includes a wide range of treat­ment options for replacing lost tooth substance or constructing new tooth shapes. An additive restoration concept in combina­tion with composite or ceramic restorations ensures that the tooth substance is protected. The dentist's preferences deter­mine the choice of the restoration material. In this case, a direct composite restoration was selected to close a diastema between tooth 11 and 21.


Asunto(s)
Diente , Cerámica , Materiales Dentales , Estética , Estética Dental
16.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 4466-4469, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-33018986

RESUMEN

The efficacy of implantable medical devices is limited by the longevity of devices in the body environment. Due to the aqueous and mobile-ion rich environment of tissue, robust and long-lasting encapsulation materials are critical for chronic implants. Assessing the reliability of medical devices is commonly performed through saline soak tests with reactive oxidative species at elevated temperatures and lifetime data are fit to an Arrhenius model to predict lifetime under physiological conditions. While effective, these systems often require frequent human involvement to maintain system temperature and reactive oxidative species concentration, as well as monitor sample lifetime, which makes long term testing of multiple samples difficult. Here we present an automated, low-cost, low-solution volume, and high-throughput reactive accelerated aging system to assay many thin film samples in an easy and low maintenance manner. The efficacy of up to 16 thin film coating samples can be assessed by our system through in-situ current leakage tests in a mock biological environment. We validate our system by aging thermal oxide and a-SiC thin films at 93 °C with 20 mM H2O2. Our system shows early failure of the thermal oxide compared to the a-SiC, in agreement with the current literature.


Asunto(s)
Envejecimiento , Peróxido de Hidrógeno , Materiales Dentales , Humanos , Longevidad , Reproducibilidad de los Resultados
17.
J Contemp Dent Pract ; 21(7): 808-814, 2020 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-33020368

RESUMEN

AIM: This literature review aims to update the evidence for prevention of white spot lesion (WSL) using orthodontic sealants among patients with fixed orthodontic appliances. BACKGROUND: As a major issue among orthodontists, prolonged treatment duration increases the risk of plaque development around orthodontic brackets and bands. In consequence, this can lead to heightened risk for caries development and higher possibility of WSL development around fixed orthodontic brackets. RESULTS: Increased prevalence of WSLs generally occurs during orthodontic treatment. This review explored various products of orthodontic sealants used to prevent WSL. Orthodontic sealants do not require patient compliance and thus will further lessen the burden among orthodontists as well as support enamel surface for a long period of time during treatment. Certain factors, however, are considered important in the efficacy of these sealants, such as antibacterial activity, color stability, resistance to acid and brush abrasion, and their effect on shear bond strength (SBS). CONCLUSION: The review showed that the use of orthodontic sealants in preventing WSLs during and after fixed orthodontic treatment is significantly effective. However, the bioactive glass is deemed more effective against WSL development due to its ability to immediately repair enamel surface, low cytotoxicity, and high biocompatibility. Moreover, clinical studies on bioactive glass are still needed to determine its acceptability among patients with fixed orthodontic appliance. CLINICAL SIGNIFICANCE: Development of WSL around the orthodontic brackets during treatment is a difficult task among orthodontists. As such, this review explored various strategies to effectively combat WSL development for good oral health and esthetics during orthodontic treatment.


Asunto(s)
Caries Dental/etiología , Caries Dental/prevención & control , Soportes Ortodóncicos/efectos adversos , Ortodoncia , Materiales Dentales , Estética Dental , Humanos
18.
Compend Contin Educ Dent ; 41(9): 477-482, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33001658

RESUMEN

Lithium disilicate and layered zirconia appear to be the most prevalent materials used for single-unit anterior crowns. These materials offer the necessary mechanical properties as well as sufficient optical characteristics needed in this type of restoration. There now are also more translucent versions of zirconia available that can be used for monolithic anterior restorations. This article discusses the factors that clinicians must take into account when determining a restorative material for single-unit anterior crowns. Considerations for lithium-disilicate crowns, 4 and 5 mol% yttria-containing (4Y and 5Y) zirconia materials, and layered 3Y zirconia restorations are provided.


Asunto(s)
Coronas , Diente , Materiales Dentales , Ensayo de Materiales
19.
Am J Dent ; 33(5): 243-247, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33017526

RESUMEN

PURPOSE: Concurrently with the growing interest in CAD-CAM systems, several new materials of different chemical nature have become available. As an alternative to ceramics, numerous polymer-based materials have recently been proposed for permanent prosthetic restorations. Aim of this study was to test the CAD-CAM polymer-based materials available on the market, comparing mean flexural strength, Weibull characteristic strength and Weibull modulus. METHODS: Seven types of polymer-based blocks were tested: Lava Ultimate, 3M; Brilliant Crios, Coltene; Cerasmart, GC; Block HC, Shofu; Katana Avencia, Noritake; Grandio Blocs, Voco; Tetric CAD, and Ivoclar-Vivadent. Specimens were cut out from blocks, finished, polished, and tested in a three-point bending test apparatus until failure (n=30). Flexural strength, Weibull characteristic strength, and Weibull modulus were calculated. Flexural strength data were statistically analyzed. ANOVA on Ranks was applied, followed by the Dunn's test for post hoc comparisons (P= 0.05). RESULTS: Flexural strength values (MPa) were measured (mean±standard deviation). Different letters in parentheses label statistically significant differences: Grandio Blocs 266±24(a), Brilliant Crios 259±21(ab); Tetric CAD 254±15(ab); Katana Avencia 241±29(bc); Cerasmart 221±24(cd); Lava Ultimate 196±23(de); Block HC 139±10(e). All the tested materials had flexural strengths greater than 100 MPa, thereby satisfying the requirements of ISO standards for polymer-based materials. For all the tested materials the Weibull characteristic strength was greater than 100 MPa. Weibull modulus ranged between 21.20 (Tetric CAD) and 9.09 (Katana Avencia). CLINICAL SIGNIFICANCE: Even though all the CAD-CAM polymer-based materials marketed in blocks tested in the present study satisfy the requirements of ISO standard for polymer-based materials, their flexural resistance differs significantly. The data presented in the study may be helpful to clinicians for selecting the most appropriate materials for each clinical case.


Asunto(s)
Resistencia Flexional , Polímeros , Diseño Asistido por Computadora , Materiales Dentales , Ensayo de Materiales
20.
J Indian Soc Pedod Prev Dent ; 38(3): 247-252, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33004722

RESUMEN

Background: We aimed to determine the fluoride release and fluoride-recharging ability of a sealant containing surface pre-reacted glass (S-PRG) ionomer filler particles (BeautiSealant) with a fluoride-releasing resin sealant (Helioseal F), and a glass-ionomer sealant (Fuji VII). Methodology: Forty-eight disc-shaped specimens of each material were immersed in deionized water to determine the fluoride release utilizing a fluoride ion-selective electrode. After 21 days, 8 specimens were soaked in 0.22% Sodium Fluoride solution for 2 min; 8 specimens were coated with 1.23% Acidulated Phosphate Fluoride (APF) gel for 4 min, and the fluoride-recharging ability was evaluated for 40 days. Data were analyzed using one way-ANOVA and Bonferroni post hoc tests. Results: Total fluoride release over the 21-day period was: Fuji VII > BeautiSealant > Helioseal F, (P = 0.000). After refluoridation of the specimens with 0.22% Sodium Fluoride solution, the cumulative fluoride release during the 40-day period for each material was: BeautiSealant > Fuji VII > Helioseal (P = 0.000). After exposure to 1.23% APF gel, the cumulative fluoride release during the 40-day period for each material was: BeautiSealant > Fuji VII > Helioseal F (P = 0.000). Conclusion: Glass ionomer-based sealants (Fuji VII) exhibited higher initial fluoride release whilst the surface pre-reacted glass-ionomer filler containing sealant (BeautiSealant) demonstrated superior fluoride recharging properties.


Asunto(s)
Materiales Dentales , Fluoruros , Fluoruro de Fosfato Acidulado , Electrodos de Ion-Selectivo
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