Surface Roughness Of Feldspathic Porcelain Research Articles

Effect of two polishing systems on color and surface roughness of feldspathic porcelain following orthodontic bracket debonding and composite resin removal

Objectives Orthodontic bracket removal from a porcelain crown can roughen the surface and lead to plaque accumulation, discoloration, and esthetic problems. Porcelain polishing after debonding is one strategy to decrease such consequences. This study aimed to compare the efficacy of two polishing systems (Sof-Lex discs and Meisinger polishing system) for correction of surface roughness and discoloration of porcelain after orthodontic bracket debonding. Materials and Methods Twenty porcelain blocks were evaluated in two groups of 10. First, the baseline surface roughness and color parameters of the samples were measured using atomic force microscopy and spectrophotometry, respectively. After bracket bonding, a fine cutter was used for bracket debonding, and resin remnants were removed by a tungsten carbide bur and low-speed handpiece. Samples were then polished using Sof-Lex discs (group 1) and Meisinger porcelain polishing kit (group 2). Surface roughness and color parameters were measured again. Data were analyzed using SPSS 18 through the Shapiro–Wilk test, Student’s t-test, and paired t-test at 5% level of significance. Results Porcelain color change (ΔE) was significantly greater in the Meisinger system than Sof-Lex (P < 0.001). The Rq, Ra, and Rt surface roughness parameters significantly increased in both the groups after the intervention compared to baseline (P < 0.05), but the two groups were not significantly different in this respect after the polishing procedures (P > 0.05). Conclusion The porcelain color after polishing with Sof-Lex discs was closer to the baseline. Furthermore, the two systems were not significantly different regarding surface roughness. However, Sof-Lex discs may be recommended due to lower cost.

Effect of different bleaching agents on the surface roughness and color stability of feldspathic porcelain

Objective: The aim of this study was to evaluate the effect of different bleaching agents on the surface roughness and color stability of feldspathic porcelain. Material and Methods: In this study, totally 40 disc-shaped Noritake and Ceramco 3 feldspathic porcelain and two bleaching agents (Opalescence Boost and Opalescence Pf) were used. Bleaching agents were exposed to specimens according to their protocol. Then, the surface roughness of the specimens was evaluated with profilometer and the color of the specimens was recorded by colorimeter. Statistical analysis of the data was performed with IBM SPSS Statistics 20. Results: The results showed that that there were statistically significant differences between the bleaching agents on the surface roughness of feldspathic porcelain (p<0.05). However, there were no statistically significant differences between the bleaching agents on the color stability of feldspathic porcelain (p>0.05). Conclusion: The obtained data presented that the bleaching agents increased the surface roughness and not affect the color stability of the feldspathic porcelain.KeywordsBleaching; Ceramic; Color; Surface roughness.

The effect of different surface treatment techniques on the surface roughness of feldspathic porcelain.

This in vitro study compared the effect of five different techniques on the surface roughness of feldspathic porcelain. 100 feldspathic porcelain disk samples mounted in acrylic resin blocks were divided into five groups (n=20) according to type of surface treatment: I, hydrofluoric acid (HFA); II, Deglazed surface porcelain treated with Neodymium:yttrium- aluminum-garnet (Nd:YAG) laser; III, Deglazed porcelain surface treated with Erbium:yttrium-aluminum-garnet (Er:YAG) laser; IV, Glazed porcelain surface treated with Neodymium:yttrium-aluminum-garnet (Nd:YAG) laser, V; Glazed porcelain surface treated with Erbium:yttrium-aluminum-garnet (Er:YAG) laser. The surface roughness of porcelain was measured with a noncontact optical profilometer. For each porcelain sample, two readings were taken across the sample, before porcelain surface treatment (T1) and after porcelain surface treatment (T2). The roughness parameter analyzed was the average roughness (Ra). Statistical analysis was performed using Kolmogorov-Smirnov and Wilcoxon signed rank test. Mean Ra values for each group were as follows: I, 12.64±073; II, 11.91±0.74; III, 11.76±0.59; IV, 3.82±0.65; V, 2.77±0.57. For all porcelain groups, the lowest Ra values were observed in Group V. The highest Ra values were observed for Group I, with a significant difference with the other groups. Kolmogorov-Smirnov showed significant differences among groups (p<0.001). Surface treatment of porcelain with HFA resulted in significantly higher Ra than laser groups. Both Er:YAG laser or Nd:YAG laser on the deglaze porcelain surface can be recommended as viable treatment alternatives to acid etching.

Effect of Different Acidic Agents on Surface Roughness of Feldspathic Porcelain

Objectives: The aim of this study was to evaluate the effect of different acidic agents on surface roughness of feldspathic porcelain. Materials and Methods: In this study, totally 60 disc shaped Noritake and Ceramco 3 feldspathic porcelain were used. The samples were divided into five groups and immersed in five acidic agents (coke, orange juice, lemonade, mineral water and black-carrot juice). After 168 hours, the specimens were evaluated surface roughness with profilometer. Results: The results showed that the highest surface roughness value (4.46 ± 2.9 μm) was identified in lemonade at Noritake porcelain and the lowest surface roughness value (1.06 ± 0.56 μm) was identified in mineral water at Ceramco 3 porcelain. The result of two-way analysis of variance test showed that there were no statistically significant differences between acidic agents on surface roughness of feldspathic porcelain (p > 0.05). Conclusions: The obtained data presented that the acidic drinks affected the surface roughness of feldspathic porcelain.

Comparison of the surface roughness of feldspathic porcelain polished with a novel alumina-zirconia paste or diamond paste.

This study compared the surface roughness of feldspathic porcelain polished with newly developed alumina-zirconia pastes or diamond paste. Porcelain discs were prepared and polished with sandpaper using a polishing-machine. The surface roughness (Ra) of each sample was measured using a profilometer. The samples were randomly divided into 6 groups (n=10). The control group was polished with diamond paste (DP), and the five remaining groups were polished with the newly developed alumina-zirconia paste with the following ratios of glycerin:alumina:zirconia by weight: 1:0.5:0.5 (Z0.5), 1:0.5:0.75 (Z0.75), 1:0.5:1 (Z1), 1:0.5:1.5 (Z1.5), and 1:0.5:2 (Z2). The specimens were polished for 120 s. The Ra values were determined again and the surface morphology of the porcelain samples was analyzed using SEM. The Ra values decreased as the amount of zirconia in the polishing paste increased, except for the Z2 group. The surface roughness as observed by SEM showed a correlation with the Ra values.

Caries management by risk assessment (CAMBRA) and its effect on the surface roughness of various restorative materials

Statement of problemWhether topical anticaries medicaments used in the oral environment will affect the surface integrity of restorative materials is uncertain. PurposeThe purpose of this in vitro study was to investigate the effect of various anticaries agents on the surface roughness of 3 different restorative materials. Material and methodsSixty-four specimens of each restorative material (feldspathic porcelain, Ni-Cr metal ceramic alloy, and Ti-6Al-4V titanium alloy) were prepared and separated into 4 equal groups for soaking in anticaries agents (Prevident Dental Rinse, ACT mouth wash, chlorhexidine gluconate, and water). A profilometer was used to measure surface roughness before and after soaking the materials for 2 years of simulated usage. The mean change in surface roughness for each specimen was calculated. Statistical analysis was performed with a 2-way ANOVA, followed by the Tukey HSD test (α=.05). ResultsA significant interaction was found between the materials and anticaries agents (F=2.64, P=.02). The significant interaction was between Prevident and chlorhexidine gluconate. Porcelain specimens soaked in Prevident produced a negative change (−0.072 ±0.35 μm) in surface roughness (smoother surface), while chlorhexidine gluconate produced a positive change (0.094 ±0.42 μm) in surface roughness (rougher surface). ConclusionWithin the limitations of this in vitro study, it can be concluded that Prevident Dental Rinse and chlorhexidine gluconate may cause a change in the surface roughness of feldspathic porcelain.

Surface topography and bond strengths of feldspathic porcelain prepared using various sandblasting pressures.

The purpose of this study was to determine the bond strength of composite resin to feldspathic porcelain and its surface topography after sandblasting at different pressures. In this invitro study, 68 porcelain disks were fabricated and randomly divided into four groups of 17. The porcelain surface in group 1 was etched with hydrofluoric acid. Groups 2, 3, and 4 were sandblasted at 2, 3 and 4bars pressure, respectively. Surface topography of seven samples in each of the four groups was examined by a scanning electron microscope (SEM). The remaining 40 samples received the same silane agent, bonding agent, and composite resin and they were then subjected to 5000 thermal cycles and evaluated for shear bond strength. Data were analyzed using one-way anova. The mode of failure was determined using stereomicroscope and SEM. The highest shear bond strength was seen in group 4. however, statistically significant differences were not seen between the groups (P=0.780). The most common mode of failure was cohesive in porcelain. The SEM showed different patterns of hydrofluoric acid etching and sandblasting. Increasing the sandblasting pressure increased the surface roughness of feldspathic porcelain but no difference in bond strength occurred.

Estudio comparativo in vitro de pulido de porcelana feldespática usando instrumentos intraorales y pastas diamantadas.

El presente estudio experimental in vitro compara mediante el uso de un rugosímetro (Surftest - III, Mitutoyo), la rugosidad superficial de porcelana feldespática abrasionada y después pulida, usando diferentes procedimientos con instrumentos intraorales como fresa diamantada grano fino, kits de pulido y pastas diamantadas de diferente granulación. Para el grupo control, las muestras fueron glaseadas y luego pulidas usando instrumentos extraorales en un laboratorio dental. Se realizaron pruebas estadísticas ANOVA y de comparación múltiple. Los resultados indican que una combinación adecuada de una fresa de diamante grano fino, las 3 gomas del kit Porcelain Polishing (Jota) y las pastas diamantadas Diamond Polish (Ultradent) de 1 pm y de 0,5 pm, usados en ese orden producen una menor rugosidad superficial en las muestras. Estos hallazgos son importantes ya que indican como alternativa, el pulido intraoral, después de abrasionar una restauración cerámica.

Performance of a novel polishing rubber wheel in improving surface roughness of feldspathic porcelain

Replacing glazing with polishing is still controversial in terms of the surface roughness of dental porcelains. This study investigated the polishing performance of a ceramic-polishing rubber wheel (CP-RW), which contains large uniform and rounded silicon carbide particles and small diamond particles, in improving the surface roughness of two feldspathic porcelains for sintering and CAD/CAM milling. Using a confocal laser scanning microscopy, the changes in the surface roughness parameters were evaluated before and after polishing or glazing for three surface treatment groups: SofLex polishing, CP-RW polishing, and Glazing. Regardless of the parameters, all treatments reduced roughness values (repeated measures ANOVA, p<0.05). The roughness values obtained after CP-RW polishing were lower than those obtained after SofLex polishing and glazing (2-way ANOVA, p<0.05). Polishing both ceramics with CP-RW made the surfaces smooth with the lowest roughness values in all parameters. The effect was dependent on the materials used.

The effects of porcelain finishing and polishing systems on the surface roughness of feldspathic porcelain: An in vitro study

Introduction: This in vitro study deals with the efficiency of surface polishing systems after the glaze layer of the ceramic has been altered using a medium grit diamond to simulate the chairside adjustment of a restoration. Materials and Methods: Forty porcelain discs measuring 10 mm × 3 mm with a metal substructure of 10 mm × 1 mm were used. Ceramco 3(ultra-low fusing feldspathic porcelain) porcelain system was used to fabricate the discs on the metal substructure. A medium grit diamond was used to simulate the chairside adjustment procedures. Ten samples were glazed (control group) and 30 samples were finished and polished using three finishing and polishing agents. (experimental group; Shofu Ceramaster, Kohinoor diamond polishing paste and Sof-Lex discs).These 40 samples and the initial roughened samples were subjected to a profilometer evaluation to obtain results in Ra (Average roughness in µm) and Rz (Mean maximum peak -to-valley height in µm). Results: One way ANOVA revealed a statistical significant difference amongst Ra values of the group. Amongst the finished and polished group of samples, the samples polished with Shofu Ceramaster diamond-impregnated silicon showed the highest efficiency among the three finishing and polishing systems followed by samples polished with Kohinoor L highly filled diamond polishing paste and the least efficient polishing system was the samples polished using Sof-Lex discs. The Rz (Mean peak-to-valley height) values showed the same results as the Ra values. Conclusion: The study concluded that among the three finishing and polishing systems tested, Shofu Ceramaster diamond impregnated silicon rubbers are the most efficient with significant differences in surface roughness compared to roughened samples

Effect of three bleaching agents on the surface properties of three different esthetic restorative materials

Statement of problem Information related to the effect of night-guard vital bleaching procedure on the surface properties of esthetic dental restorative materials is incomplete. Purpose The aim of this study was to examine the effects of 3 proprietary carbamide peroxide bleaching agents on the surface properties of 3 dental esthetic restorative materials. Material and methods Three bleaching products (Nite White, Opalescence, and Rembrandt Lighten Gel) and 3 restorative materials (Duceram, Fuji II LC, and Silux Plus) were studied. A stainless steel mold and a 6-mm–thick polytetrafluoroethylene plate with a 1-cm–diameter hole were used to prepare 30 standardized specimens for each of the 3 restorative materials tested. Each group was divided into 3 subgroups (n=10). Two specimens from each subgroup were selected to form a control group. Three different carbamide peroxide bleaching agents were applied to each restorative material group for 8 hours per day for 30 days, respectively. Initial roughness measurements (Ra measured in μm) were made by use of a profilometer, at repeated intervals of 24 hours, 48 hours, 1, 2, 3, and 4 weeks (30 days). Surface topography of the specimens was assessed by scanning electron microscopy, and results were compared with the control group graphically. Surface structure and alterations of atomic weight percentages of element were made by use of energy-dispersive x-ray microanalysis. One-way analysis of variance was used to evaluate the surface roughness measurements. Significant results were evaluated with Fisher and Duncan’s multiple range test ( P<.005) Result Surface roughness values for all restorative materials increased during the bleaching procedure. The only significant increase was found with the effect of Rembrandt bleaching gel on modified glass ionomer cement (mean Ra was 0.48 μm initially, 0.5 μm at 24 hours, 0.75 μm at 2 weeks, and 0.83 μm at 30 days). Surface roughness values increased significantly during the first 2 weeks ( P<.005) for all bleaching groups of each restorative material, and no significant changes were seen in the following periods. SEM micrographs of the feldspathic porcelain specimens for each bleaching agent appeared to be similar to the control group. All of the modified glass ionomer specimens revealed serious cracking areas, whereas microfilled composite specimens showed increased surface porosity and cracks in certain areas when compared with control specimens. Surface spectral analyses results indicated a decrease in the SiO 2 content in the feldspathic porcelain and the microfilled composite groups for all bleaching agents. Modified glass ionomer specimens bleached with Nite White and Rembrandt showed an increase in mass percentage of SiO 2, whereas Opalescence specimens showed a decrease. However, there were no significant differences between the groups. Conclusion Within the limitations of this study, no significant difference was found between bleaching agents. Most changes occurred in the first 2 weeks; the products tested were relatively stable in the following test periods. No significant change in the surface roughness of feldspathic porcelain was observed. On the other hand, the microfilled composite tested showed slight changes in the surface roughness. Significant changes were found for the modified glass ionomer cement ( P>.005).