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1.
Int J Prosthodont ; 33(3): 328-332, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32320187

RESUMO

PURPOSE: To examine microwave heating for the purpose of ceramic glazing as an alternative to conventional methods in terms of color stability. MATERIALS AND METHODS: Thirty disk-shaped specimens (11 × 2 mm) of VITA VM 9, VITA VM 13, VITA VMK 95, and IPS e.max Ceram veneers were prepared (n = 30 each). The specimens were further divided into three subgroups according to surface finishing procedure (polishing, conventional oven glazing, or microwave glazing [n = 10 each]). The related surface finishing procedure was applied according to the manufacturers' instructions. Color differences (ΔE) of the ceramic samples stored in a coffee solution at 37°C for 168 hours were determined using spectrophotometry. Data were analyzed using two-way ANOVA. The group differences were analyzed using Tukey HSD test. RESULTS: Microwave-glazed specimens showed similar ΔE values to conventionally glazed specimens for the tested ceramics (P > .05). Polished specimens showed higher ΔE values than glazed specimens for the investigated ceramic materials, and the difference was significant for VITA VMK 95 and Vita VM9 (P ≤ .05). CONCLUSION: Microwave glazing has the advantage of decreasing glazing time to a few minutes and could be considered as an alternative method to conventional oven glazing and polishing with respect to color stability.


Assuntos
Polimento Dentário , Micro-Ondas , Cerâmica , Cor , Porcelana Dentária , Teste de Materiais , Propriedades de Superfície
2.
Chin J Dent Res ; 23(1): 63-69, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32232231

RESUMO

OBJECTIVE: To determine the effects of different polishing protocols and curing times on the surface roughness (SR), surface gloss (SG) and surface hardness (SH) of a bulk-fill composite resin (BCR). METHODS: A total of 30 block-shaped specimens (40 mm long × 10 mm wide × 2 mm thick) were made from Filtek Bulk-Fill composite resin and divided into two groups (n = 15) according to curing time (10 and 40 seconds). Each group was subdivided into five groups (n = 3) according to the polishing protocol: laboratory polishing with different silicon paper grits (G1:1200) → (G2:2400) → (G3:4000). Chairside polishing was performed using a series of Sof-Lex spiral (G4) and Jiffy Polisher (G5) points. The SR was measured by a surface profilometer. A Vickers indenter was used to test the SH, and a glossmeter was used to determine the SG at 60 degrees. The SR, SG and SH were quantified before and after polishing. A scanning electron microscopy (SEM) evaluation was then performed. RESULTS: The curing time did not affect the surface properties of the BCR (P > 0.05). Significant differences in SR (ranging from 0.1 to 2 µm) and SG (ranging from 20 to 90 GU [gloss unit]) were found according to the type of polishing protocol (P < 0.05). The SH values following different polishing protocols were significantly higher (ranging from 82 to 95 VH [Vickers hardness]) than the polishing values obtained before the polishing protocols (P < 0.05). CONCLUSION: The tested chairside polishing protocols presented lower SG and higher SR values than the laboratory polishing protocols.


Assuntos
Resinas Compostas , Polimento Dentário , Dureza , Teste de Materiais , Propriedades de Superfície
3.
Dent Mater ; 36(3): 442-455, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32001023

RESUMO

OBJECTIVES: The main goal of this work is to evaluate the suitability of nanostructured zirconia pieces obtained by robocasting additive manufacturing (AM), for dental applications. METHODS: The density, crystalline structure, morphology/porosity, surface roughness, hardness, toughness, wettability and biocompatibility of the produced samples were compared with those of samples obtained by conventional subtractive manufacturing (SM) of a similar commercial zirconia material. Chewing simulation studies were carried out against dental human cusps in artificial saliva. The wear of the material was quantified and the wear mechanisms investigated, as well as the influence of glaze coating. RESULTS: AM samples, that revealed to be biocompatible, are slightly less dense and more porous than SM samples, showing lower hardness, toughness and wettability than SM samples. After chewing tests, no wear was found both on AM and SM samples. However, the dental wear was significantly lower when AM samples were used as counterbody. Concerning the glazed samples, both coated surfaces and dental cusps suffered wear, being the cusps' wear higher than that found for unglazed samples. More, cusps tested against AM coated samples suffered less wear comparatively to those opposed to SM coated samples. SIGNIFICANCE: Overall, the results presented in this paper show that AM processed nanostructured zirconia can be used in dental restorations, with important advantages from the point of view of processing and tribological performance. Moreover, the option for glaze finishing should be carefully considered both in SM and AM processed specimens.


Assuntos
Porcelana Dentária , Desgaste de Restauração Dentária , Polimento Dentário , Humanos , Teste de Materiais , Impressão Tridimensional , Propriedades de Superfície , Zircônio
4.
Int J Prosthodont ; 33(2): 217-223, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32069347

RESUMO

PURPOSE: To evaluate the surface roughness values of zirconium oxide samples that were gradually polished using a commercially available polishing system and polishing paste. MATERIALS AND METHODS: A total of 50 rectangular specimens of predetermined size (10 × 10 × 3 mm) were sintered from zirconium oxide. Samples were randomly assigned to one of five groups (n = 10 each): control, coarse (Co), fine (F), super fine (SF), or polishing paste (PP). In the control group, no polishing was done; in the Co group, a coarse polisher was used; and the specimens in the remaining three groups underwent additional processing with a fine rubber abrasive. For SF and PP samples, subsequent treatment with a super fine polisher was applied. Finally, for the PP group, a goat-hair brush with diamond polishing paste was used. An optical profilometer was used to evaluate roughness average (Ra) in micrometers (µm). ANOVA and Games-Howell post hoc tests were utilized to detect differences between groups. The significance level was set to α = .05. RESULTS: Surface roughness gradually decreased with further polishing throughout the groups: control Ra = 0.525 ± 0.099 µm; Co Ra = 0.252 ± 0.038 µm; F Ra = 0.196 ± 0.035 µm; SF Ra = 0.114 ± 0.031 µm; and PP Ra = 0.054 ± 0.020 µm. Statistically significant differences were detected among all groups (P < .05). CONCLUSION: A surface roughness of 0.054 µm can be achieved if a full zirconia polishing protocol is used. Zirconium oxide can be polished to various surface roughnesses using commercially available polishing products.


Assuntos
Polimento Dentário , Zircônio , Teste de Materiais , Microscopia Eletrônica de Varredura , Propriedades de Superfície
5.
Braz Oral Res ; 33: e121, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31939500

RESUMO

The objective of the study was to analyze the surface area (SA) of the wear caused by simulated chewing on human enamel and opposing restorative material, namely: composite resin (CR), porcelain fused to metal (PFM), lithium disilicate (LD), or monolithic zirconia (MZr). Forty-eight premolars were selected as enamel specimens and divided randomly into 4 groups (n = 48; n =12) used as antagonists in chewing simulation (250,000 loading cycles) against one of the four selected test materials. Enamel and material specimens were scanned and evaluated under digital microscope, and wear SA (mm2) were recorded. Descriptive statistics, paired t-test, one-way ANOVA, and post-hoc Tukey-HSD tests were used for statistics (p < 0.05). The smallest and largest SA were exhibited by enamel against LD (0.80 mm2) and PFM (1.74 mm2), respectively. PFM (3.48 mm2) showed the largest SA and CR (2.28 mm2) showed the smallest SA. Paired t-test for SA values showed significant difference (p < 0.05) in all wear comparisons between materials and enamel antagonists. The wear of materials were greater than that of their respective enamel antagonists (p < 0.05). One-way ANOVA of the logarithmic means of wear SA revealed significant differences (P<0.05). Post-hoc Tukey test revealed significance for PFM (p < 0.05) with other materials. Wear of all test materials was greater compared to the wear of enamel antagonists. PFM and LD caused the largest and the smallest enamel wear, respectively. CR, LD, and MZr are more resistant than PFM to wear after simulated chewing against enamel.


Assuntos
Resinas Compostas/química , Esmalte Dentário/química , Porcelana Dentária/química , Mastigação , Ligas Metalo-Cerâmicas/química , Desgaste dos Dentes/etiologia , Zircônio/química , Adolescente , Adulto , Análise de Variância , Polimento Dentário/métodos , Humanos , Processamento de Imagem Assistida por Computador , Teste de Materiais , Microscopia/instrumentação , Valores de Referência , Estatísticas não Paramétricas , Propriedades de Superfície , Adulto Jovem
6.
J Oral Sci ; 62(1): 40-42, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31996521

RESUMO

The purpose of this study was to evaluate the influence of various polishing protocols on the surface roughness of polyetheretherketone (PEEK) and identify an effective polishing method of dental prostheses at the chairside. The PEEK specimens were assigned to seven groups with different protocols: no additional polishing (NT); polishing using a rubber point (C); polishing using "silky shine" (S); polishing using "aqua blue paste" (A); protocol C followed by protocol S (CS); protocol C followed by protocol A (CA); and protocol C followed by protocols S and A (CSA). The surface roughness (Sa and Ra) of the polished surfaces was measured. The surface roughness decreased in the following order of groups: NT, C, S, CS, CSA, CA, and A. In Groups C and S, wide deep pits formed by abrasive grains of SiC paper were observed, whereas only fine linear structures were observed on the surface in other groups. With respect to the polishing protocol of PEEK, clinically acceptable surface roughness was obtained using a soft polishing brush and agent for more than 3 min.


Assuntos
Polimento Dentário , Cetonas , Teste de Materiais , Polietilenoglicóis , Propriedades de Superfície
7.
Clin Oral Investig ; 24(1): 395-403, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31102049

RESUMO

OBJECTIVES: To test the impact of polishing strategies on zirconia properties. MATERIALS AND METHODS: One hundred eight zirconia specimens were divided into nine groups (n = 12/group). Seven groups were polished in the white-stage with either (1) a felt wheel (FW), (2) a felt wheel combined with a polishing paste (FWP), (3) a goat hair brush (GB), (4) a goat hair brush combined with a polishing paste (GBP), (5) a green-state finishing kit (FK), (6) a universal polisher (UP), or (7) with SiC polishing paper (PP), and sintered. Thereafter, the seven groups were divided into two subgroups each and polished using (1) a fine polisher (one-step, n = 6) or (2) a rough and fine polisher (two-steps, n = 6). The positive control group (polish-lab-kit, PLK) was sintered and polished in two-steps. The no polished group (NP) acted as negative control group. Translucency (T%) was measured after white-stage polishing and sintering, and after sintered-stage polishing. Surface free energy (SFE), surface roughness (SR), and flexural strength (FS) were determined. Data were analyzed using one-way ANOVA with Tukey-B post-hoc, t test, and Wilcoxon-test (p < 0.05). RESULTS: FWP, GB, FK, UP, and PP presented decreased T% after one-step, while FWP, GB, GBP, FK, and UP presented decreased T% following two-steps polishing. FW showed the highest T% after white-stage, one-, and two-steps polishing. PP presented the lowest SFE. Two-steps polishing resulted in a lower SR for FW, FWP, GB, FK, UP, and PP and increased FS in all groups. CONCLUSIONS: White-stage polishing improved zirconia properties. Two-steps polishing in the sintered stage, especially when combined with a polishing paste, can decrease SR and increase T% and FS. CLINICAL RELEVANCE: With polishing in the sintered-stage impairing the polishing material and being time consuming, alternatives such as white-stage polishing should be investigated.


Assuntos
Polimento Dentário , Zircônio , Teste de Materiais , Microscopia Eletrônica de Varredura , Polônia , Propriedades de Superfície
8.
J Prosthet Dent ; 123(2): 330-337, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31079884

RESUMO

STATEMENT OF PROBLEM: How occlusal adjustments and finishing of high-translucent monolithic zirconia restorations affect their mechanical behavior is unclear. PURPOSE: The purpose of this in vitro study was to investigate the effect of grinding, finishing, and hydrothermal degradation on the roughness, flexural strength, and reliability of fully stabilized zirconia (FSZ) and partially stabilized zirconia (PSZ) for monolithic restorations. MATERIAL AND METHODS: Specimens of PSZ and FSZ were divided into 5 groups: control (Ctrl); those ground by using coarse diamond rotary instrument (Gr); those that underwent grinding, polishing (diamond rubber), and glazing (GrPolGl); those that underwent grinding and glazing (GrGl); and those that underwent grinding and polishing (GrPol). These groups were subdivided into nonaged and hydrothermally aged in autoclave (134 °C, 200 kPa). Three-point bend tests (flexural strength [FS]) were performed (n=30), and roughness (Ra) was measured by using a contact profilometer (n=30). The Weibull moduli were obtained from the FS data. The intergroup FS was analyzed by the Kruskal-Wallis test and Student-Newman-Keuls method, and the intragroup FS, Mann-Whitney tests (α=.05). RESULTS: The median FS for PSZ (MPa) for the aforementioned groups is as follows: Gr (1147.8)=GrPol (1210.3)>GrPolGl (815.6)>GrGl (569.7)=Ctrl (583.0). The FS for FSZ (MPa) for the aforementioned groups is as follows: GrPolGl (404.2)=GrGl (427.0)

Assuntos
Polimento Dentário , Zircônio , Humanos , Teste de Materiais , Reprodutibilidade dos Testes , Propriedades de Superfície
9.
J Evid Based Dent Pract ; 19(4): 101314, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31843176

RESUMO

OBJECTIVE: The objective of this review was to evaluate the effect of subgingival debridement by ultrasonic debridement (UD) in comparison with subgingival air polishing (SubGAP) during periodontal maintenance. METHODS: A systematic search of electronic databases was conducted to identify publications from January 01, 2000, to December 21, 2018. Publication selection, data extraction, and risk of bias assessment were performed by two reviewers independently. The addressed problem-intervention-comparison-outcomes question was "For patients in the periodontal maintenance phase, is SubGAP more likely to result in better clinical outcomes than UD?" RESULTS: From a total of 435 articles identified, 6 studies were included. Although none of them was evaluated to have a low risk of bias, overall, the main reason was that blinding of personnel was almost impossible to achieve for the study design. Owing to the heterogeneity, the data from included studies could not be synthesized. Most of the included studies suggested no statistical difference in pocket-depth reduction, except for one which showed UD was superior to SubGAP. In terms of clinical attachment loss and gingival regression, no treatment was indicated to have more benefits than the other based on the present evidence. SubGAP had a preferable comfort level compared with UD, as reported. It must be noted that none of included studies' follow-up time was more than 1 year. CONCLUSION: The clinical efficacy of SubGAP compared with that of UD for periodontal maintenance remains inconclusive on account of limited evidence. To date, neither SubGAP nor UD showed superior clinical effect when compared. High-quality, well-designed clinical studies are still needed to ascertain the long-term clinical stability.


Assuntos
Raspagem Dentária , Ultrassom , Desbridamento , Polimento Dentário , Humanos , Desbridamento Periodontal , Índice Periodontal , Resultado do Tratamento
10.
Int J Oral Maxillofac Implants ; 34(6): 1299-1305, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31711072

RESUMO

PURPOSE: To assess surface characteristics and implant stability after implantoplasty performed by two different instrument sequences regarding material loss, surface roughness, and fracture load resistance. Additionally, operators' subjective experience during instrumentation and the damage to neighboring teeth were evaluated. MATERIALS AND METHODS: Titanium implants were placed in the position of both first maxillary molars in models exposing 6 mm of their surface. Implantoplasty was performed in phantom heads: Exposed surfaces were instrumented with diamonds and Arkansas stones or abrasive stones and silicone polishers. Operators reported on abrasion, gloss, effectiveness, and tactility using a visual analog scale (VAS). Residual wall thickness of implants was measured on radiographs, material abrasion using three-dimensional (3D) scans, and surface roughness by contact profilometry. Maximum bending moments were measured. RESULTS: Residual thickness and weight loss were comparable after both treatments (0.3 ± 0.1 and 0.25 ± 0.07 mm and 0.22 ± 0.01 g, and 0.03 ± 0.01 mm and 0.02 ± 0.01 g, respectively, P > .05). Mean surface roughness was lower (P = .0001) for the group with the silicone polishers (0.4 ± 0.2 µm) compared with the group employing diamonds (0.8 ± 0.1 µm). Maximum bending moments showed neither intergroup differences nor stability loss compared with untreated implants. The stone-and-silicone polisher group showed less abrasion (4.6 ± 2.2) and higher gloss values (8.1 ± 1.4) than the diamond-and-Arkansas group (3.1 ± 1.3 and 4.1 ± 2.1, respectively). Superficial tooth injuries at proximal neighbor teeth were common (73% and 80%). CONCLUSION: Implantoplasty did not weaken implant stability. The use of silicone polishers revealed lower surface roughness. Regarding surface smoothness, the instrumentation sequence employing silicon carbide and Arkansas stones followed by silicone polishers seems to be superior to the combination of diamond and Arkansas stones.


Assuntos
Implantes Dentários , Titânio , Polimento Dentário , Teste de Materiais , Microscopia Eletrônica de Varredura , Propriedades de Superfície
11.
Braz Dent J ; 30(5): 511-518, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31596336

RESUMO

This study evaluated the influence of zirconia surface finishes on the wear of an enamel analogue. 40 zirconia discs were divided into four groups: control (without finish); glazed; polished; polished and glazed. All samples were subjected to wear against steatite antagonists. The specimens underwent roughness, topographic, scanning electron microscopy (SEM) and wettability analyses. Quantitative wear measurements were performed on both steatites and discs. To measure wear of steatites the weight before and after the test and the diameter after the test were used. Profilometer measurements were performed to determine the wear on discs. Roughness, volumetric wear and mass loss were analyzed using the Kruskal-Wallis and Dunn tests (5%), while contact angle values were analyzed with One-way ANOVA and Tukey tests (5%). The polished group had the lowest roughness means, being statistically different from the other groups (p-value=0.0001). The glazed group presented the lowest steatite volumetric wear (p-value=0.0001), but not statistically different from the polished and glazed group, whereas these groups presented the highest zirconia volumetric wear, with statistically different (p-value=0.0002) compared to the others. SEM showed irregularities on the control groups surface, grooves on the polished group, and a homogeneous surface for the glazed group with a few pores. All groups presented contact angles lower than 90 degrees, characterizing hydrophilic surfaces. It can be concluded that just glazed zirconia caused less wear on the antagonist when compared to no finish and polished zirconia.


Assuntos
Porcelana Dentária , Zircônio , Polimento Dentário , Teste de Materiais , Propriedades de Superfície
12.
Gen Dent ; 67(6): 62-66, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31658028

RESUMO

This study evaluated how exposure to ultraviolet (UV) light affected the gloss of composite resins following application of resin-based surface sealants (SSs). Thirty composite resin discs were fabricated using cylindrical molds and randomly assigned to 1 of 5 SS groups (n = 6 each). Both sides of each disc received a polyester film clear matrix surface finish, and then rotary finishing and polishing procedures were performed on 1 side only. Six baseline measurements for each disc surface were performed using a 60-degree-angle gloss meter. The finished and polished side then received an SS application and was polymerized with an LED light through a polyester film matrix. Gloss measurements were then obtained. All specimens were then exposed to an artificial UV light source for a total of 382 hours, after which final gloss measurements were made. A 2-way repeated-measures analysis of variance and Student-Newman-Keuls pairwise multiple comparison tests revealed statistically significant differences between the SS materials and surface treatments (P < 0.05). No statistically significant (P > 0.05) differences were found between the surfaces that were mechanically finished and polished and those that only received a polyester film finish. However, all specimens exhibited significantly (P < 0.0001) higher gloss readings after SS application. Following UV exposure, all SS specimens exhibited significantly (P < 0.0001) lower gloss readings. The study results suggest that application of SSs to composite resin discs increases the gloss on a short-term basis; however, long-term exposure of SSs to an artificial UV light source might have a negative effect on the surface properties. Thus, dentists need to periodically evaluate composite resin restorations.


Assuntos
Polimento Dentário , Raios Ultravioleta , Resinas Compostas , Materiais Dentários , Humanos , Teste de Materiais , Propriedades de Superfície
13.
J Prosthet Dent ; 122(3): 332.e1-332.e5, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31383532

RESUMO

STATEMENT OF PROBLEM: Resin-coating agents can be used to fill microstructural defects within composite resin restorations, which might result in a smoother surface. Nevertheless, data about the color stability and surface roughness of coated restorations are lacking. PURPOSE: The purpose of this in vitro study was to compare the surface roughness and color stability of restorations before and after application of different resin-coating agents. MATERIAL AND METHODS: Forty specimens of composite resin (Filtek Z250) (diameter×height, 6×2 mm) were divided into 5 groups according to the surface treatments (n=8 per group): control (CTR), Fortify (FT), Lasting touch (LT), BisCover (BIS), and Fill Glaze (FG). The specimens were evaluated for surface roughness by using a profilometer with 3 readings for each specimen (separated by 300 µm) before immersion in a staining solution (coffee) and after 5 days immersed in coffee and for color stability (▵E) by using a spectrophotometer before being immersed in coffee (initial reading) and after 6 hours, 12 hours, 1, 2, 3, 4, and 5 days. RESULTS: Two-way ANOVA with repeated measures and the Tukey test showed that the CTR group showed the highest roughness values, similar to those of the FT and LT groups. The BIS and FG groups showed lower roughness than the other groups but similar results when compared with each other. All groups, except LT, showed increased roughness values after immersion in coffee solution, and the BIS group showed the lowest variation over time. Color alterations were found for all groups, with the CTR group showing the lowest ▵E values when compared with the other groups except for the BIS group. No correlation was found between surface roughness and degree of color change (P=.401). CONCLUSIONS: The BisCover surface sealant showed the lowest surface roughness and the best color stability. Surface sealants can be used to fill microcracks and microgaps but should not be used as a substitute for polishing.


Assuntos
Resinas Compostas , Polimento Dentário , Cor , Materiais Dentários , Teste de Materiais , Propriedades de Superfície
14.
Am J Dent ; 32(4): 169-173, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31436936

RESUMO

PURPOSE: To evaluate the effect of diamond toothpastes on the gloss surface of five resin composites. METHODS: 30 discs of each resin composite in A2 shade [Filtek Supreme Ultra (FS), Tetric EvoCeram (TE), IPS Empress Direct (ED), Charisma (CC), Venus Diamond (VD)] were made. The samples were divided into three groups according to the toothpaste: Colgate Total Clean Mint (control) (CTC), Candida White Diamond (CWD) and Emoform-F Diamond (EFD). After standardized polishing, the samples were brushed using a toothbrushing simulator, and gloss measurements were assessed at baseline and 15, 30, 45, 60, 75, 90, 105 and 120 minutes. RESULTS: Diamond toothpastes behaved dif-ferently from each other: the CWD and CTC groups presented the lowest values compared to EFD (P< 0.05). Nanofilled composites presented higher gloss values than other composites when brushed with various toothpastes (P< 0.05). The addition of diamond particles as abrasives in toothpastes can affect resin composites' surface gloss. CLINICAL SIGNIFICANCE: The various types of abrasive particles present in toothpastes may harm resin-composite restorations.


Assuntos
Polimento Dentário , Cremes Dentais , Resinas Compostas , Diamante , Teste de Materiais , Propriedades de Superfície
15.
Oper Dent ; 44(3): E122-E132, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31046648

RESUMO

OBJECTIVES: The objective of this in vitro study was to compare, with a threshold value of 200 nm, the surface roughness obtained when using 12 different polishing systems on four different composite resins (microfill, nanofill, and two nanohybrids). METHODS AND MATERIALS: A total of 384 convex specimens were made using Durafill VS, Filtek Supreme Ultra, Grandio SO, and Venus Pearl. After sandblasting and finishing with a medium-grit finishing disc, initial surface roughness was measured using a surface roughness tester. Specimens were polished using 12 different polishing systems: Astropol, HiLuster Plus, D♦Fine, Diacomp, ET Illustra, Sof-Lex Wheels, Sof-Lex XT discs, Super-Snap, Enhance/Pogo, Optrapol, OneGloss and ComposiPro Brush (n=8). The final surface roughness was measured, and data were analyzed using two-way analysis of variance. Pairwise comparisons were made using protected Fisher least significant difference. RESULTS: There were statistical differences in the final surface roughness between polishing systems and between composite resins (p<0.05). The highest surface roughness was observed for all composite resins polished with OneGloss and ComposiPro Brush. Enhance/Pogo and Sof-Lex Wheels produced a mean surface roughness greater than the 200-nm threshold on Filtek Supreme Ultra, Grandio SO, and Venus Pearl. Data showed that there was an interaction between the composite resins and the polishing systems. CONCLUSIONS: A single polishing system does not perform equally with all composite resins. Except for Optrapol, multi-step polishing systems performed generally better than one-step systems. Excluding Enhance/Pogo, diamond-impregnated polishers led to lower surface roughness. Durafill VS, a microfill composite resin, may be polished more predictably with different polishers.


Assuntos
Resinas Compostas , Polimento Dentário , Diamante , Teste de Materiais , Propriedades de Superfície
16.
J Prosthodont ; 28(7): 818-825, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31066483

RESUMO

PURPOSE: To evaluate surface roughness and topography of different zirconia-based restorations at various steps of finishing and polishing. MATERIALS AND METHODS: Seventy-five zirconia discs were fabricated and divided into 3 layered and 2 monolithic groups: layered conventional (VM9; Vita), layered pressed (PM9; Vita), layered digital (TriLuxe Forte; Vita), opaque monolithic (Ceramill Zi; Amann Girrbach), and translucent monolithic (Zolid FX; Amann Girrbach). Surface roughness testing (Ra, Rz) and scanning electron microscopy were performed at the glazed, unglazed, finished, polished, super-polished, and super-polished with diamond paste steps. One-way ANOVA and Tukey tests were used for statistical analysis. RESULTS: There were significant differences in all groups among the different steps (p < 0.001, F = 77.67 for layered conventional; p < 0.001, F = 133.90 for layered pressed; p < 0.001, F = 47.94 for layered digital; p < 0.001, F = 48.05 for zirconia opaque; p < 0.001, F = 43.91 for zirconia translucent). For the layered groups, glazed stage was significantly different from all other steps (p < 0.001). For the layered conventional and digital groups, polishing using diamond paste was not significantly different from the polished and super-polished steps (p = 0.448, p = 0.153), while for the layered pressed group, polishing using diamond paste was not significantly different from the super polished step (p = 0.815). For monolithic groups, there were no significant differences between the polished and super-polished steps (p = 0.957 for zirconia opaque, p = 1.00 for zirconia translucent). Both the diamond paste and super-polished steps showed no significant differences (p = 0.620, p = 0.550) from the glazed surface in the opaque zirconia group. CONCLUSIONS: Surface roughness of monolithic and layered zirconia was improved by polishing; however, only opaque zirconia reached the level of surface roughness of the glazed stage. Type of buildup affected the surface roughness of adjusted ceramics, with monolithic zirconia showing lower surface roughness than layered zirconia. Polishing with diamond paste provided no significant improvement in the surface roughness of monolithic or layered zirconia.


Assuntos
Polimento Dentário , Zircônio , Porcelana Dentária , Teste de Materiais , Microscopia Eletrônica de Varredura , Propriedades de Superfície
17.
J Prosthodont ; 28(5): 564-571, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30933395

RESUMO

PURPOSE: To evaluate the roughness and color change of a conventional acrylic resin and a bis-acryl resin, submitted to different types of polishing and exposed to a staining solution. MATERIALS AND METHODS: One hundred specimens were manufactured from an autopolymerizing conventional acrylic resin (Duralay, shade 66) (n = 50) and a bis-acryl resin (Protemp 4, shade A3) (n = 50) according to the manufacturers' instructions. Specimens were subdivided into 10 groups (n = 10), according to the type of resin and polishing method, including no-polishing (control groups for acrylic resin [tungsten bur finishing] and bis-acryl resin [cotton and alcohol]), Enhance System, Edenta kit, Labordental kit, and sandpaper. The specimens were immersed in a staining solution (coffee at 60°C) for 7 days. Surface roughness was evaluated before the first immersion (baseline - Ra1) and after 7 days (Ra2). The color change (∆E) was determined after 24 hours (∆E1) and 7 days (∆E2), by CIE L* a* b* scale. Data were statistically analyzed with 3-way ANOVA for repeated measures test and Tukey test (α = 0.05). RESULTS: According to 3-way ANOVA test, material, polishing techniques, and polishing*material factors exhibited statistically significant influence (p < 0.0001) on the roughness, and, for color change, material, polishing techniques, time, polishing*material, and material*time factors were statistically significant (p < 0.0001). The polishing techniques successfully reduced the surface roughness of acrylic resin groups, when compared to control (p < 0.001), but for bis-acryl resin, results were not different from the control group (Enhance: p = 0.954, Edenta: p = 0.866, sandpaper: p = 0.366, Labordental: p = 0.945). Surface roughness was not affected by the immersion in staining solution for 7 days. Color change of acrylic resin groups after 24 hours and 7 days of immersion exhibited a clinically acceptable value (ΔE < 3.7) with the exception of the Enhance group, and all bis-acryl resin groups exhibited a clinically unacceptable color change value (ΔE > 3.7) independent of polishing technique and time interval (∆E1 and ∆E2). CONCLUSIONS: Roughness of both materials was similar when the polishing techniques studied were performed, although Ra values were superior to the clinically acceptable values (0.20 µm), and were not affected by the immersion protocol studied; however, when esthetics are critical, the selection of material type is more important than the surface treatment technique used, and bis-acryl resin was more susceptible to clinically unacceptable color change after immersion in a staining solution.


Assuntos
Polimento Dentário , Estética Dentária , Cor , Resinas Compostas , Teste de Materiais , Prostodontia , Propriedades de Superfície
18.
Braz Dent J ; 30(2): 164-170, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30970060

RESUMO

This study evaluated the effect of different finishing-polishing protocols on surface roughness, gloss, morphology and biaxial flexural strength of pressable fluorapatite glass ceramic. Thirty ceramic discs (12x1 mm) were produced and divided into five groups (n=6): CT: control (glaze); DA: fine grit diamond bur; DG: DA + new glaze layer; DP: DA + felt disk with fine grit diamond paste; DK: DA+ sequential polishing with silicon abrasive instruments, goat hair brush and cotton wheel. The specimens were analyzed for surface roughness (Ra) under profilometry and atomic force microscopy (AFM). Gloss was measured with spectrophotometry and micromorphology with scanning electron microscopy (SEM). Flexural strength was assessed by biaxial flexural strength test. Data were analyzed using one-way ANOVA and Tukey's post hoc test (a=0.05). DK showed the lowest surface roughness values and DA presented the highest in the perfilometer analysis. No significant differences were observed in the AFM for the CT, DG and DK groups, which presented the lower surface roughness; DA and DP had the higher Ra values. The DA, DP and CT showed the lowest surface gloss values, and the reflectance was significantly different from those observed for DK and DG groups. SEM analysis revealed the smoothest surface for DK group, followed by DG and CT groups; DA and DP groups exhibited variable degrees of surface irregularities. No significant differences were observed among groups for the biaxial flexural strength. The polishing protocol used in DK group can be a good alternative for chairside finishing of adjusted pressable fluorapatite glass ceramic surfaces.


Assuntos
Polimento Dentário , Porcelana Dentária , Cerâmica , Resistência à Flexão , Teste de Materiais , Microscopia Eletrônica de Varredura , Propriedades de Superfície
19.
Niger J Clin Pract ; 22(4): 496-502, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30975953

RESUMO

Aim: The aim of this research was to investigate the effect of microwave glazing, conventional oven glazing, and polishing on surface roughness and wettability of porcelains. Materials and Methods: The initial surface roughness values (Ra0) of the prepared specimens for four different porcelains (Vita VM 9, VitaVM 13, Vita VMK 95, IPS e.maxCeram) were determined by profilometry. Then, the specimens were divided randomly into three groups as polishing, conventional oven glazing, and microwave glazing. Final surface roughness values were evaluated by profilometry (Ra1) and scanning electron microscopy. Wettability of glazed specimens were evaluated by contact angle goniometer. Results: Although microwave-glazed specimens had lower Ra1 values compared with the conventional oven-glazed ones for IPS e.maxCeram (P < 0.05), there were not any statistically significant differences between these two procedures in terms of Ra1 values for the other porcelains (P > 0.05). Microwave-glazed specimens had lower wettability values than conventional oven-glazed ones for Vita VM 9. Conclusions: Microwave glazing procedure may be considered as an alternative method because of the advantages of providing volumetric heating, time, and energy saving.


Assuntos
Ligas Dentárias/química , Polimento Dentário/métodos , Porcelana Dentária/química , Teste de Materiais/métodos , Microscopia Eletrônica de Varredura , Micro-Ondas , Molhabilidade , Cerâmica , Temperatura Alta , Humanos , Propriedades de Superfície
20.
Microsc Res Tech ; 82(7): 1215-1223, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30938008

RESUMO

The aim of this study was to provide important insights into the effects of four different dental polishing protocols (one single-step and one multi-step either followed or not by diamond paste polishing) on the 3D surface morphology of two representative dental resin-based nanocomposites (a nanofilled and a nanohybrid composite) by means of digital image analysis and processing techniques. The 3D surface morphology was investigated by atomic force microscopy. Segmentation, statistics of height distributions (described by statistical parameters, according to ISO 25178-2: 2012) and Minkowski functionals were applied to the images to characterize the spatial patterns of analyzed samples at micrometer scale. The nanofilled composite had significantly lower values of height parameters in comparison with nanohybrid one. Multi-step polishing protocol generated a statistically significant smoother finish for both tested materials, than one-step polishing protocol, even when it was followed by diamond paste polishing. Diamond paste polishing generated a statistically significant smoother surface of tested samples. This suite of surface analysis tools is important in the research and manufacture of these dental resin-based nanocomposites, where material surfaces have a key role in the functionality of objects.


Assuntos
Polimento Dentário , Nanocompostos/química , Propriedades de Superfície , Resinas Compostas , Materiais Dentários/química , Diamante , Teste de Materiais , Microscopia Eletrônica de Varredura
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