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1.
Oper Dent ; 46(1): E60-E67, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33882138

RESUMO

CLINICAL RELEVANCE: The clinical performance of both conventional and flowable giomer restorative materials was particularly good in Class I restorations after three years of service. SUMMARY: This study evaluated and compared the clinical performance of a flowable and a conventional giomer restorative material after three years. Forty-four pairs of restorations (total n=88) were placed in Class I cavities with either a flowable giomer (Beautifil Flow Plus F00; Shofu Inc, Kyoto, Japan) or a conventional giomer restorative material (Beautifil II; Shofu Inc) after the application of a dentin adhesive (FL-Bond II; Shofu Inc) and a flowable liner (Beautifil Flow Plus F03; Shofu Inc). After 3 years, 39 pairs of restorations were evaluated with the modified United States Public Health Service criteria, and digital color photographs of restorations were taken at each patient visit. The evaluation parameters were as follows: color match, marginal integrity, marginal discoloration, retention, secondary caries formation, anatomic form, surface texture, and postoperative sensitivity. Evaluations were recorded as a clinically ideal situation (Alpha), a clinically acceptable situation (Bravo), or a clinically unacceptable situation (Charlie). Data were analyzed with Fisher's exact and McNemar tests (α=0.05).None of the restorations showed retention loss, postoperative sensitivity, secondary caries, or color change. The performance of Beautifil II in terms of marginal integrity, marginal discoloration, and surface anatomic form was significantly lower at the 36-month follow-up than at baseline (p=0.007). There were no significant differences between the baseline and 36-month follow-up scores for the other criteria for Beautifil II (p>0.05). No differences were found between the baseline and the 36-month follow-up scores for any of the criteria for Beautifil Flow Plus F00 (p>0.05). No statistically significant difference in overall clinical performance was found between the 2 materials after 36 months (p>0.05).The three-year clinical performance of both restorative materials (Beautifil Flow Plus F00 and Beautifil II) was very good and not significantly different for any of the parameters evaluated.


Assuntos
Cárie Dentária , Restauração Dentária Permanente , Cor , Resinas Compostas , Cárie Dentária/terapia , Adaptação Marginal Dentária , Materiais Dentários , Seguimentos , Humanos , Japão , Propriedades de Superfície
2.
Oper Dent ; 46(1): E11-E20, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33882141

RESUMO

CLINICAL RELEVANCE: A prereacted, glass-ionomer filler fluoride-containing resin composite had lower remineralization potential than glass-ionomer cements but was able to inhibit enamel demineralization; thus, it may be an option for restoring dental surfaces for patients at high risk of caries. SUMMARY: Evidence is lacking on the use of surface prereacted glass-ionomer filler resin composites to inhibit demineralization and that simulate real clinical conditions. The present laboratory study evaluated the potential of such composites to prevent demineralization and quantified fluoride (F) and other ions released from restorative materials after a dynamic pH-cycling regimen applied to the tooth material interface in vitro. The pH-cycling regimen was assessed by measuring surface hardness (SH) along with energy dispersive X-ray spectroscopy (EDX). METHODS AND MATERIALS: Ninety blocks of bovine enamel were subjected to composition analysis with EDX, and were further categorized based on SH. The blocks were randomly divided into 6 treatment groups (n=15 each): F IX (Fuji IX Extra; GC Corporation); IZ (Ion Z, FGM); F II (Fuji II LC, GC Corporation); B II (Beautifil II, Shofu); F250 (Filtek Z250 XT, 3M ESPE); and NT (control, no treatment). The blocks were subjected to a dynamic pH-cycling regimen at 37°C for 7 days concurrently with daily alternations of immersion in demineralizing/remineralizing solutions. EDX was conducted and a final SH was determined at standard distances from the restorative materials (150, 300, and 400 µm). RESULTS: The EDX findings revealed a significant increase in F concentration and a decrease in Ca2+ in the enamel blocks of group B II after the pH-cycling regimen (p<0.05). SH values for groups F IX, IZ, and F II were greater than those for groups B II, F250, and NT at all distances from the materials. CONCLUSIONS: The results suggest that each of 3 restorative materials, F IX, IZ, and F II, partially inhibited enamel demineralization under a dynamic pH-cycling regimen.


Assuntos
Desmineralização do Dente , Animais , Cariostáticos , Bovinos , Resinas Compostas , Esmalte Dentário , Materiais Dentários , Fluoretos , Cimentos de Ionômeros de Vidro/uso terapêutico , Humanos , Cimentos de Resina , Desmineralização do Dente/prevenção & controle
3.
Int J Oral Maxillofac Implants ; 36(2): 327-331, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33909723

RESUMO

PURPOSE: To compare the temperature changes during the setting process of two provisional crown materials, polymethyl methacrylate (PMMA)-based acrylic resin (Ac) and bis-acryl composite resin (Co), at the first thread surface of one-piece implants. MATERIALS AND METHODS: Twenty-two 3.3-mm-diameter one-piece implants were divided into two groups according to the provisional restoration material. Implants were mounted on a Plexiglas apparatus. A K-type thermocouple was fixed at the most coronal thread. Baseline (Bl Temp) and maximal (Max Temp) temperatures of both groups were recorded during the curing process. Total heat flux (THF) at the implant surface and thermal amplitude (Temp-Amp) were calculated. Differences between groups were compared using a t test for unpaired observations. RESULTS: Upon curing, a statistically significant increase in the Max Temp from the Bl Temp was detected in both groups, with a greater increase in the Ac compared with the Co group. The Temp-Amp and the THF were two times greater in the Ac group than the Co group. CONCLUSION: Significant heat is produced during the polymerization of PMMA-based resin and bis-acryl composite resin provisional crowns in one-piece implants. To decrease the risk of thermal challenge at the implant cervical aspect associated with restoration of immediately loaded implants, bis-acryl composite resin should be used.


Assuntos
Resinas Acrílicas , Implantes Dentários , Resinas Compostas , Materiais Dentários , Teste de Materiais , Polimetil Metacrilato , Propriedades de Superfície
5.
Braz Dent J ; 32(1): 91-97, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33914009

RESUMO

This study investigated the effects of oxygen inhibition and finishing/polishing procedures on the composite resin properties. One bulk-fill and two conventional composite resins (nanoparticle and microhybrid) were evaluated. Specimens were prepared using 4 surface treatments: control, no treatment; Gly, oxygen inhibition with glycerin; FP, finishing and polishing; Gly + FP, glycerin followed by finishing and polishing. The degree of conversion (DC) was measured using Fourier Transformed Infrared Spectroscopy (FTIR) immediately and after 15 days (n=5). Color stability (ΔEab, and ΔE00) and opacity were evaluated using a spectrophotometer after 15 days of immersion in coffee, using the CIELAB system (n=5). Data were analyzed by two-way ANOVA and Tukey tests (α=0.05) and opacity by two-way repeated-measures ANOVA. Glycerin usage increased significantly the DC however had no influence on the ΔEab, ΔE00 and, opacity values. Finishing and polishing reduced ΔEab and ΔE00 values, regardless of composite resins. Microhybrid showed higher opacity, followed by the nanoparticle and bulk fill, regardless of surface treatment. Post-polymerization polishing procedures resulted in lower conversion than using an oxygen inhibitor agent (Gly condition), but similar staining caused by coffee.


Assuntos
Resinas Compostas , Oxigênio , Cor , Materiais Dentários , Polimento Dentário , Teste de Materiais , Propriedades de Superfície
6.
J Adhes Dent ; 23(2): 91-110, 2021 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-33825424

RESUMO

PURPOSE: The goals of this review are (1) to describe the evidence behind the use of ceramics vs composite resin to restore teeth with anterior veneers using a minimally-invasive strategy; and (2) to discuss the choice of materials and techniques for anterior veneer restorations. OVERVIEW: In recent years new adhesive restorative materials and techniques have been introduced in dentistry, including nanofilled composite resins for direct restorations, new ceramic materials that combine esthetics and strength, and polymer/ceramic materials for indirect restorations that are fabricated chairside using CAD/CAM technology, allowing the dentist to design, mill, and cement the restoration in one session. In spite of the novelty and new technology behind the introduction of new materials, the available evidence that backs some of these materials does not justify their use over similar materials or techniques that have been used by dentists for some years. Notwithstanding the success of laminate veneers and the popularity of new materials and digital techniques, the classical direct composite resin veneer is still very popular among clinicians and taught in dental schools and continuing education courses. Direct composite resin veneers are usually more affordable than indirect veneers, less invasive of the tooth structure, and easier to repair. Current composite resin materials can be finished to a tooth-like appearance, but they are susceptible to alterations of the surface gloss and potential discoloration of the composite resin. On the other hand, the preparation for indirect veneers is generally more invasive and the respective restorations are more difficult to repair. In addition, the esthetic outcome of bonded ceramic restorations still depends on the clinical behavior of the dentin adhesive and resin luting cement used to bond the restoration to the tooth structure. CONCLUSIONS: The ultimate goals of any restorative treatment are to restore function and esthetics, prevent recurrent caries lesions and bacterial leakage into the pulp space, save tooth structure, and promote the well-being of our patients. The armamentarium of new dental materials for esthetic clinical procedures has increased exponentially in the last few years. The use of different materials and techniques for anterior veneer restorations must be based on sound evidence rather than on the marketing hype or testimonials.


Assuntos
Resinas Compostas , Facetas Dentárias , Cerâmica , Materiais Dentários , Porcelana Dentária , Humanos , Cimentos de Resina
7.
Compend Contin Educ Dent ; 42(2): 93-94, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33735582

RESUMO

Composite materials remain a mainstay as a restorative option in dentistry. This article reviews some of the most recent updates and projected future trends in dental composites, along with curing lights and matrix systems.


Assuntos
Luzes de Cura Dentária , Bandas de Matriz , Resinas Compostas , Materiais Dentários , Teste de Materiais
8.
Dent Mater ; 37(5): 840-848, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33658138

RESUMO

OBJECTIVE: To evaluate optical properties, and translucency and opalescence parameters of one-shaded resin-based composites. METHODS: Three one-shaded resin composites (OM - Omnichroma; VP - Venus Pearl; and VD - Venus Diamond) and a group-shaded resin composite (FU- Filtek Universal A2) were used. Three composite discs from each material were fabricated for each of the following thickness: 0.5, 1.0 and 2.0 mm. Diffuse reflectance was measured against white and black backgrounds using a calibrated spectroradiometer, CIE D65 illuminant and the CIE 45°/0° geometry. Translucency parameter (TP) was calculated using ΔEab * and ΔE00. Scattering (S) and absorption (K) coefficients and transmittance (T%) were calculated using Kubelka-Munk's equations, and a reflection spectrophotometer was used to measure the opalescence parameter (OP). Data was statistically analyzed using Kruskal-Wallis, Mann-Whitney tests, and VAF coefficient. RESULTS: Spectral distributions of S, K and T were wavelength dependent, showing significant differences between materials of the same thickness and for different thicknesses of the same material (p < 0.001). OM showed the greatest translucency values for all thicknesses. Translucency decreased as thickness increased with statistically significant differences (p < 0.005). Values of ΔTPab and ΔTP00 between thicknesses were above of translucency thresholds for all materials. VP and VD showed the lowest OP values. SIGNIFICANCE: One-shaded resin-based composites showed different optical behavior than the group-shaded resin-based composite. Understanding the optical behavior of the one-shaded resin-based composites is essential to optimize their clinical performance.


Assuntos
Resinas Compostas , Materiais Dentários , Cor , Iridescência , Luz , Teste de Materiais
9.
Gen Dent ; 69(2): 40-46, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33661113

RESUMO

The objective of the present study was to assess the influence of energy and hydroelectrolytic beverages on the color stability and fluorescence of composite resins. Three composite resins (Amelogen, Filtek Z350 XT, and Filtek Bulk Fill) were analyzed at 4 different time periods: at baseline (T0) and after 1 (T1), 2 (T2), and 3 (T3) months of storage. Thirty specimens of each material were prepared and divided into subgroups (n = 10) based on the type of solution in which they were immersed for 1 hour a day at 37°C: distilled water (control), Red Bull, and Gatorade. Color stability and fluorescence tests were performed at each timepoint. Three-way repeated-measures analysis of variance (ANOVA) tests were used to evaluate the influences of material, immersion solution, and time on the color stability and fluorescence values (α = 0.05). The Bonferroni test was used as a post hoc test to compare the mean values between the groups (α = 0.05). For color change, ANOVA showed a statistically significant influence of all isolated factors and their interactions. Overall, for all periods of analysis, Amelogen showed significantly higher fluorescence values than the other composite resins after storage in all solutions. In this in vitro study, energy and hydroelectrolytic beverages altered the color stability and fluorescence of the studied materials at all timepoints. The potential for future color alterations should be considered before anterior composite resin restorations are placed in patients who consume high quantities of these beverages.


Assuntos
Bebidas , Resinas Compostas , Bebidas/efeitos adversos , Cor , Materiais Dentários , Humanos , Teste de Materiais , Propriedades de Superfície
10.
Dent Mater ; 37(4): 559-567, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33685651

RESUMO

OBJECTIVE: To determine the polymerization shrinkage (%) and shrinkage stress (MPa) characteristics of ultra-rapid photo-polymerized bulk fill resin composites. METHODS: Two ultra-rapid photo-polymerized bulk fill (URPBF) materials: PFill and PFlow were studied, along with their comparators ECeram and EFlow. PFill contains an addition fragmentation chain transfer (AFCT) agent. The URPBR materials were irradiated using two different 3 s high irradiance protocols (3000 and 3200 mW/cm2 based on Bluephase PowerCure and VALO LCUs, respectively) and one 10 s standard protocol (1200 mW/cm2 based on a Bluephase PowerCure LCU). Bonded disk and Bioman II instruments were used to measure Polymerization shrinkage % and shrinkage stress MPa, respectively, for 60 min at 23 ± 1 °C (n = 5). Maximum shrinkage-rate and maximum shrinkage stress-rate were also calculated for 15 s via numerical differentiation. The data were analyzed via multiple One-way ANOVA and Tukey post-hoc tests (α = 0.05). RESULTS: PFill groups, regardless of their irradiance protocol, showed significantly lower PS than the comparator, ECeram (p < 0.05). However, PFlow irradiated via different protocols, was comparable to EFlow and ECeram (p > 0.05). PFill consistently produced stress results which were significantly lower than ECeram (p < 0.05) and were comparable for both high irradiance protocols (p > 0.05). PFlow only exhibited significantly higher shrinkage stress when polymerized with the 3 sVALO protocol (p < 0.05). The maximum shrinkage strain-rate (%/s) was significantly lower in PFill-10s and PFill-3s groups (using PowerCure LCU) compared to ECeram. However, no differences were seen between PFlow and EFlow (p > 0.05). The maximum shrinkage stress-rate of PFill and PFlow was comparable between different irradiation protocols, as well as to their comparator ECeram (p > 0.05). SIGNIFICANCE: High irradiation protocols over ultra-short periods led to slightly lower shrinkage strain but slightly higher stress, possibly due to reduced network mobility. The AFCT agent incorporated in PFill composite seemed to reduce shrinkage stress development, even with high irradiance protocols.


Assuntos
Resinas Compostas , Materiais Dentários , Teste de Materiais , Polimerização
11.
Dent Mater ; 37(5): 905-913, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33691991

RESUMO

OBJECTIVES: To evaluate the effect of laser fused and air abraded fluorapatite particles on flexural strength σf and fracture toughness (KIC) of Yttria tetragonal zirconia polycrystal (Y-TZP). METHODS: 160 polished Y-TZP bars received one of the following surface treatments: airborne particle abrasion (APA) with fluorapatite glass-ceramics (FGC), APA with tribochemical silica-coated alumina (CoJet), laser fused FGC using Nd:YAG Laser (FGC + Laser), while as-sintered polished specimens served as control. Initial flexural strength σfI was measured to half of the specimens, while the rest underwent cyclic fatigue (1,000,000 cycle of 15N load and 3 s contact time) followed by measuring residual flexural strength σfR. Fractographic analysis was performed and KIC was calculated. The effect of surface treatment and fatigue on flexural strength was statistically analysed using 2-way ANOVA (α = 0.05). Weibull probability was measured to assess the reliability of flexural strength. RESULTS: The highest σf before or after the fatigue was reported for the control group while the lowest was for FGC + Laser group. Cyclic fatigue significantly decreased the flexural strength of all groups except for FGC + Laser group. There was no significant difference between the KIC between the control and FGC groups, however, a significant reduction of KIC was found in the CoJet group, while FGC + Laser reported the significant lowest value compared to all groups (P = 0.00). SIGNIFICANCE: Fluorapatite glass-ceramic powder offers a promising alternative for particle abrasion of zirconia-based frameworks.


Assuntos
Materiais Dentários , Zircônio , Cerâmica , Análise do Estresse Dentário , Teste de Materiais , Reprodutibilidade dos Testes , Propriedades de Superfície , Ítrio
12.
Dent Mater ; 37(5): 875-881, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33715863

RESUMO

OBJECTIVE: Continuous efforts have been made to hasten the zirconia densification process without compromising properties. This study evaluated the long-term structural durability of microwave speed-sintered zirconia (MWZ) relative to a conventionally sintered zirconia (CZ). METHODS: As-machined dental 3Y-TZP discs (Ø12 × 1.2 mm) were speed sintered at 1450 °C for 15 min using an industrial microwave oven, while conventional sintering was conducted in a standard dental furnace at 1530 °C for 2 h. Both were followed by natural cooling. The total sintering time was 105 min for MWZ and 600 min for CZ. Groups were compared regarding density, grain size, phase composition, and fracture resistance. Structural durability was investigated employing two fatigue protocols, step-stress and dynamic fatigue. RESULTS: Compared to CZ, MWZ exhibited a slightly lower density (MWZ = 5.98 g/cm3, CZ = 6.03 g/cm3), but significantly smaller grain sizes (MWZ = 0.53 ± 0.09 µm, CZ = 0.89 ± 0.10 µm), lower cubic-zirconia contents (MWZ = 15.3%, CZ = 22.7%), and poorer translucency properties (TP) (MWZ = 13 ± 1, CZ = 29 ± 0.8). However, the two materials showed similar flexural strength (MWZ = 978 ± 112 MPa, CZ = 1044 ± 161 MPa). Additionally, step-stress testing failed to capture the fatigue effect in 3Y-TZP, whereas dynamic fatigue revealed structural degradation due to moisture-assisted slow-crack-growth (SCG). Finally, MWZ possessed a slightly higher Weibull modulus (MWZ = 7.9, CZ = 6.7) but similar resistance to SCG (MWZ = 27.5, CZ = 24.1) relative to CZ. SIGNIFICANCE: Dental 3Y-TZP with similar structural durability can be fabricated six-times faster by microwave than conventional sintering.


Assuntos
Materiais Dentários , Ítrio , Teste de Materiais , Micro-Ondas , Propriedades de Superfície , Tecnologia , Zircônio
13.
Dent Mater ; 37(5): 758-771, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33715864

RESUMO

OBJECTIVE: Digital image correlation (DIC) is a non-contact image processing technique for full-field strain measurement. Although DIC has been widely used in engineering and biomechanical fields, it is in the spotlight only recently in dental materials. Therefore, the purpose of this review paper is introducing the working principle of the DIC technique with some modifications and providing further potential applications in various dental materials and related fields. METHODS: The accuracy of the algorithm depending on the environmental characteristics of the DIC technique, as well as the advantages and disadvantages of strain measurement using optical measurements, have been elaborated in dental materials and related fields. Applications to those researches have been classified into the following categories: shrinkage behavior of light-cured resin composite, resin-tooth interface, mechanical properties of tooth structure, crack extension and elastic properties of dental materials, and deformation of dental restoration and prosthesis. This classification and discussion were performed using literature survey and review based on numerous papers in the international journals published over the past 20 years. The future directions for predicting the precise deformation of dental materials under various environments, as well as limitations of the DIC technique, was presented in this review. RESULTS: The DIC technique was demonstrated as a more effective tool to measure full-field polymerization shrinkage of composite resin, even in a simulated clinical condition over the existing methods. Moreover, the DIC combined with other technologies can be useful to evaluate the mechanical behavior of material-tooth interface, dentine structure and restorative and prosthetic materials with high accuracy. Three-dimensional DIC using two cameras extended the measurement range in-plane to out-of-plane, enabling measure of the strain directly on the surface of dental restorations or prosthesis. SIGNIFICANCE: DIC technique is a potential tool for measuring and predicting the full-field deformation/strain of dental materials and actual prostheses in diverse clinical conditions. The versatility of DIC can replace the existing complex sensor devices in those studies.


Assuntos
Resinas Compostas , Processamento de Imagem Assistida por Computador , Materiais Dentários , Restauração Dentária Permanente , Imageamento Tridimensional , Teste de Materiais , Polimerização , Estresse Mecânico
14.
Dent Mater ; 37(5): 755-757, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33752947
15.
J Prosthet Dent ; 125(5): 824.e1-824.e8, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33775390

RESUMO

STATEMENT OF PROBLEM: Modifications have been made in the microstructure and sintering parameters of monolithic zirconia to improve esthetics qualities and avoid chipping of 2-layer restorations. However, how these modifications affect the physical and mechanical properties of zirconia is unclear. PURPOSE: The purpose of this in vitro study was to compare the influence of different sintering parameters on the microstructure, 4-point flexural strength, density, and grain size of 2 commercially available zirconia advocated for the fabrication of monolithic dental prostheses and 1 commercially available zirconia for use as a core material. MATERIAL AND METHODS: Three presintered blocks (Ceramill Zolid, Prettau, and IPS e.max ZirCAD) were used. Specimens were cut and sintered as per the manufacturer's recommendation or as per a modified heating protocol. Ceramill Zolid (Z1450) was sintered at 1450 °C, Prettau (P1600) was sintered at 1600 °C, and IPS e.max ZirCAD (I1530) was sintered at 1530 °C by following the manufacturer's heating protocol. Groups Ceramill Zolid Z1530 and Z1600 were sintered at temperatures higher than the manufacturer's recommendation. Specimens from each group (n=13) were analyzed with X-ray diffraction (XRD), density calculus, average grain size measurement, and 4-point flexural tests. Data were compared by using ANOVA (α=.05). RESULTS: XRD analysis showed the presence of a tetragonal metastable phase in all groups before and after sintering. No significant differences were found in relative density values for the 3 Ceramill groups (5.98 g/cm3). Groups I1530 (6.03 g/cm3) and P1600 (6.03 g/cm3) had similar density results greater than 6.00 g/cm3. The average grain size of all groups remained lower than 1 µm. P1600 had the highest grain size (0.817 µm), and Z1450 presented the lowest grain size (0.465 µm). P1600 showed the most homogeneous flexural strength and the highest Weibull modulus (m=8.22). Z1530 presented the lowest Weibull modulus (m=4.58). IPS e.max ZirCAD (I1530) had the highest flexural strength (1057.41 ±150.54 MPa), and Ceramill Zolid Z1450 had the lowest (621.01 ±138.08 MPa). CONCLUSIONS: The flexural strength, microstructure, crystal phase, and grain size of the analyzed zirconia varied as per the sintering processing. The IPS e.max ZirCAD had the highest flexural strength (1057.41 ±150.54 MPa), followed by Prettau zirconia (864.18 ±118.21), with a statistically significant difference (P<.05). The Ceramill Zolid zirconia presented the lowest flexural strength, as well as the lowest reliability for all sintering parameters used (Z1450: 621.01 ±138.08 MPa and m=5.42; Z1530: 713.10 ±175.44 MPa and m=4.58; Z1600: 630.15 ±112.08 MPa and m=6.87). At a lower heating rate (8 °C/min), the final density increased and excessive grain growth in group Z1530 was prevented.


Assuntos
Materiais Dentários , Resistência à Flexão , Cerâmica , Teste de Materiais , Reprodutibilidade dos Testes , Estresse Mecânico , Propriedades de Superfície , Ítrio , Zircônio
16.
Br Dent J ; 230(5): 294-300, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33712779

RESUMO

Objectives To present the treatment approach for the restoration of localised anterior erosive wear using a combination of dental materials.Clinical considerations A patient presented in a private dental practice concerned about the aesthetics of his anterior teeth. The patient's history and clinical examination revealed erosive wear on the labial and palatal aspects of his maxillary central incisors and right lateral incisor. The formulated treatment plan was to restore the teeth in a conservative way. A diagnostic wax-up was performed and confirmed with the patient with chairside mock-up. The treatment provided included direct composite restorations, replacement of a porcelain-fused-to-metal crown on his left lateral incisor with a porcelain-fused-to-zirconia crown, and lithium disilicate ceramic veneers on the worn labial surfaces of the central incisors and the right lateral incisor. The preparations for the ceramic veneers were carried out with the aid of the diagnostic mock-up, thus minimising the need for tooth removal of the worn teeth.Conclusions Pre-operative planning for tooth surface loss cases can help to ensure that little or no remaining tooth structure is removed during the restorative procedures. A strict bonding protocol is crucial to ensure longevity of the restorations.


Assuntos
Facetas Dentárias , Estética Dentária , Cerâmica , Materiais Dentários , Porcelana Dentária , Humanos , Incisivo , Coroa do Dente
17.
Artigo em Inglês | MEDLINE | ID: mdl-33528447

RESUMO

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.


Assuntos
Materiais Dentários , Restauração Dentária Permanente , Resinas Compostas , Análise do Estresse Dentário , Humanos , Teste de Materiais , Estresse Mecânico
18.
São Paulo; s.n; 20210219. 78 p.
Tese em Português | LILACS, BBO - Odontologia | ID: biblio-1147715

RESUMO

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.


Assuntos
Resinas Acrílicas , Materiais Dentários , Antifúngicos
19.
Int J Prosthodont ; 34(1): 47-53, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33570519

RESUMO

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.


Assuntos
Prótese Dentária , Zircônio , Materiais Dentários , Porcelana Dentária , Análise do Estresse Dentário , Teste de Materiais
20.
Bull Tokyo Dent Coll ; 62(1): 15-26, 2021 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-33583880

RESUMO

A range of experimental designs have been used in destructive testing of composite resin CAD/CAM crowns. Various materials have been adopted for the abutment in such tests, including human or bovine dentin, stainless steel, PMMA, and composite resin, the selection of which is made in accordance with study objective or preference of the researcher. The purpose of this study was to determine how the material selected for the abutment material affected fracture load and maximum displacement. Destructive tests were conducted on composite resin crowns of the same design. Three types of material were used for the abutments together with 2 types of adhesive material. Images of each sample were acquired before destruction using a microfocus X-ray CT scanner to confirm the feasibility of a non-destructive test.The load required to fracture the composite CAD/CAM resin crowns depended on the abutment material used, with a decrease being observed in the order of composite resin, stainless steel, and PMMA. Maximum displacement decreased in the order of PMMA, composite resin, and stainless steel. Differences in the material used for setting (adhesive resin or polycarboxylate cement) showed no effect on fracture load. These results indicate that the load required to achieve destruction of resin CAD/CAM crowns varies according to the abutment material used.


Assuntos
Resinas Compostas , Planejamento de Prótese Dentária , Animais , Bovinos , Coroas , Materiais Dentários , Análise do Estresse Dentário , Humanos , Teste de Materiais , Cimentos de Resina
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