Effects of polishing systems on surface properties and color stability of 3D-printed resin restoratives.

Background and objective: Finishing and polishing techniques have great importance on the long-term success and aesthetics of the composite restorations. This study aimed to investigate the effect of three finishing and polishing systems on surface roughness and color changes of four different posterior composites. Materials and Methods: Four different posterior composites, nanohybrid, nano-fill, sonic-activated bulk-fill and microhybrid resin-based composite, and three different finishing and polishing systems, Sof-Lex discs, Astropol® and TOR VM discs were used in the study. The disc specimens (15 disc for each resin composite with total n=60) were 10 mm in diameter and 2 mm in height. Before and after finishing and polishing procedure, surface roughness was measured with a profilometer device and the Ra values were recorded. Color changes was examined using spectrophotometer and (ΔE) values were calculated. Data were tabulated and statistically analyzed using analysis of variance and Tukey’s test at significance level of p 0.05) although all composites showed a smoother surface after finishing and polishing procedures. As regard to color changes (ΔE) statistically significant difference was found between composite groups and finishing and polishing system used (p < 0.05). A direct correlation between Ra and ΔE values was found. Conclusions: 1.surface roughness and color stability of resin composite restorations depend mainly on the material compositions and polishing procedure. 2. The effectiveness of the polishing systems was material dependent. 3. Among the material tested, Nanohybrid presented the smoothest surfaces and the least color changed material. 4. The polishing systems in this study, the best system was the TOR VM discs polishing system with respect to the surface roughness and color changes values. 5. Developments in finishing and polishing systems are important for the creation of ideal restorations and are associated with the increased clinical success of dental practitioners

This study evaluated the effect of different chairside polishing systems on the surface roughness and topography of monolithic zirconia. Thirty-five monolithic zirconia specimens (Lava PLUS, 3M ESPE) were fabricated and divided into five groups of seven and polished with the following: Group 1 (WZ)-Dura white stone followed by Shofu zirconia polishing kit; Group 2 (SZ)-Shofu zirconia polishing kit; Group 3 (CE)-Ceramiste porcelain polishers; Group 4 (CM)-Ceramaster porcelain polishers; and Group 5 (KZ)-Komet ZR zirconia polishers. All specimens were ground with a fine-grit diamond bur prior to polishing procedures to simulate clinical finishing. Baseline and post-polishing profilometric readings were recorded and delta Ra values (difference in mean surface roughness before and after polishing) were computed and analyzed using one-way analysis of variance and Scheffe post hoc test (p<0.05). Representative scanning electron microscopy (SEM) images of the ground but unpolished and polished specimens were acquired. Delta Ra values ranged from 0.146 for CE to 0.400 for KZ. Delta Ra values for KZ, WZ, and SZ were significantly greater than for CE. Significant differences in delta Ra values were also observed between KZ and CM. The SEM images obtained were consistent with the profilometric findings. Diamond-impregnated polishing systems were more effective than silica carbide-impregnated ones in reducing the surface roughness of ground monolithic zirconia.

The purpose of this in vitro study was to investigate the effect of polishing systems on the microleakage of composite and polyacid-modified composite resins. Class V cavities were prepared at the cemento-enamel junction of 80 freshly extracted posterior teeth. The prepared teeth were randomly divided into two groups and restored with conventional or polyacid-modified composite resins. The restored teeth were stored in distilled water at 37 degrees C for 1 week after removal of excess restorative with diamond finishing burs. The restored teeth were then divided into four groups of ten and finished/polished using the following systems: Two Striper micron finishing system (MFS), Sof-Lex XT (Sof-Lex), Enhance composite finishing and polishing system (Enhance), and Shofu composite finishing kit (Shofu). The finished restorations were subjected to dye penetration testing. Results showed that the microleakage resistance at both enamel and dentin margins of composite and polyacid-modified composite resins are not significantly affected by the different polishing systems.

The purpose of this study was to evaluate the color stability of repaired aesthetic restorative resin matrix materials after immersion in coffee and the effect of polishing systems after staining. One hundred and eighty cylindrical discs (8 mm × 2 mm) were prepared using a conventional nano-fill resin composite (Clearfil Majesty Esthetic A2 shade) with round cavities (3 × 1 mm). Cavities were repaired by three resin composite materials: Clearfil Majesty Esthetic A2 shade, one-shaded nano-fill resin composite (Omnichroma) and group-shaded nano-hybrid resin composite (Optishade, medium shade). Each group was polished with three polishing systems (n = 20); aluminum oxide (Soflex Spiral Wheels, 3M ESPE), silicon carbide (Occlubrush, Kerr, CA, USA) and diamond particulate (Twist Dia Spiral Wheels, Kuraray, Okayama, Japan). Color change (ΔE00) measurements were performed with a spectrophotometer at the baseline. Half of the polished samples were either kept in distilled water or immersed in coffee for 15 days, and color measurements were repeated before and after polishing. Statistical analysis was performed using the Kruskal–Wallis test. Repaired samples showed different color correspondence values in all groups. All three restorative materials showed significant color changes (ΔE00) after immersion in coffee (p ≤ 0.05). Repolishing of stained samples showed color improvement values in all groups. The content of the polishing system played an important role in removing the stains.

Secondary caries is an important factor in the replacement of the restorations, and it is thought that fluoride-releasing materials may prevent this problem. Furthermore, the fluoride release of the materials may be increased by polishing process. Available knowledge about the effect of polishing systems (PS) on the fluoride release of materials is limited. Therefore, this study was conducted to evaluate the effect of PS on the fluoride release of fluoride-containing materials. Restorative materials were divided into 6 groups: Fuji IX GP, Fuji II, Dyract XP, Beautifil II, Beautifil-Bulk, and Filtek Ultimate. Each group was also divided into four subgroups: Mylar strip, Sof-Lex Discs, Sof-Lex Diamond, and OneGloss. Fluoride release was determined using a fluoride ion-selective electrode. Surface roughness was evaluated with a profilometer. Two-way repeated measure and one-way ANOVA tests were used for statistical analysis. The initial rapid fluoride release was observed only in Fuji IX. The PS increased the fluoride release of Fuji IX and Fuji II and Dyract XP materials while reducing the fluoride release of resin-based materials. The highest surface roughness values were obtained with OneGloss. Further, a significant relationship between fluoride release and surface roughness was found. The polishing provides an increase in fluoride release, especially in glass-ionomer-based materials. This article revealed that there is a relationship between fluoride release and surface roughness. Proper PS must be chosen according to the material to provide the best clinical benefits in terms of fluoride release and surface roughness.

Effect of polishing systems on stain susceptibility and surface roughness of nanocomposite resin material

Background: The polishing of surface roughness is an important characteristic of composite resins and is directly related to the longevity of the restoration and patient comfort. Different polishing systems utilize different protocols, as reported in the literature. This systematic review (SR) aimed to synthesize and analyze the available scientific evidence about the effect of polishing systems on the surface roughness of nano-hybrid and nano-filling composite resins. Methods: The study protocol of this SR was registered at the International Prospective Register of Systematic Reviews -PROSPERO- (CRD4201705653). A search was conducted in PubMed-Medline, Scopus, LILACS, EMBASE, for the period 2007–2020. Quality appraisal and a descriptive analysis of the papers that met the inclusion criteria were conducted. Results: 18 records were included. Seven polishing systems (PS) of one step were found, seven PS of two steps, eight PS of three steps, three PS of four steps, and four PS of five steps. Polishing protocols (PP) varied, with application times ranging from 10 s to 60 s with speeds between 10,000 and 30,000 RPM. Regarding composition, the aluminum oxide was one of the most important components used to achieve a smooth surface. Conclusions: Multistep polishing systems were the most effective (i.e., Astropol and Sof-Lex Discs).

ObjectiveThe aim of this study was to investigate the surface roughness, gloss and microhardness values ​​of 3D-printed permanent resins after the use of polishing systems.Materials and methodsIn this study, a total of 112 specimens were prepared from permanent resin using SLA and DLP 3D printers, with each material group comprising 56 specimens of 10 mm in diameter and 2 mm in thickness. One-step, two-step and multi-step polishing systems were applied to the prepared samples. Polishing systems were classified into two subgroups according to the use of diamond polishing paste. Surface roughness, microhardness, and gloss values were measured for all specimens following the polishing procedures. Statistical analysis was conducted using a two-way analysis of variance (ANOVA) (p < 0.05).ResultsApplication of one-step, two-step and multi-step polishing systems to 3D-printed resin specimens resulted in significantly lower surface roughness and higher gloss values (p < 0.05). The use of polishing paste following all systems further reduced surface roughness and increased gloss (p < 0.05). After two-step and multi-step polishing systems, the surface roughness of the paste-applied groups decreased below 0.2 μm and the gloss increased above 80 GU. Polishing procedures also enhanced the microhardness of the specimens (p < 0.05). However, the application of polishing paste after one-step, two-step, and multi-step systems did not result in a statistically significant difference in microhardness values (p > 0.05).ConclusionsApplication of two-step and multi-step polishing systems to 3D-printed permanent resin specimens significantly reduces surface roughness while enhancing microhardness and gloss values. While the application of polishing paste after polishing systems did not influence microhardness, it positively affected surface roughness and gloss, thereby potentially enhancing clinical success.

Polishing of resin composites ensures optimal esthetics and longevity. Effective polishing techniques for conventional multi-shade resin composites are well documented. However, less is known regarding acceptable polishing for newer single-shade universal resin composites. This study compared the surface roughness of five universal resin composites (Omnichroma, Neo Spectra, Charisma Diamond One, One Shade) and one conventional multi-shade resin composite (Palfique Asteria) following the use of three polishing systems (one-step, Enhance PoGo; two-step, EVE Diacomp Plus Twist; three-step, Sof-Lex) and Mylar strip (without polishing). A total of 240 specimens were prepared (n=40 for each resin composite). The specimens were grouped into four subgroups (n=10) based on the polishing system applied. The surface roughness of all specimens was evaluated using a non-contact three-dimensional optical profilometer. One randomly selected specimen from each subgroup underwent scanning electron microscope examination. Surface roughness was significantly affected by the resin composite type and the polishing system used (p<0.05). The study groups were ranked by surface roughness, from lowest to highest, across all tested materials as follows: Mylar strip < Enhance PoGo < Sof-Lex < EVE Diacomp. The surface roughness values of the universal resin composites were comparable to the multi-shade nanofilled resin composite in all polishing systems.

This study was undertaken to examine the effect of three different polishing systems on surface roughness of five newly developed resin composites. Three microhybrid composites (Point 4, Kerr, Orange, CA; Esthet-X, Dentsply/Caulk, Milford, DE; Vitalescence, Ultradent, South Jordan, UT, USA), one microfilled composite (Renamel Microfill, Cosmedent, Chicago, IL, USA), and one experimental microhybrid composite (FZB, Ivoclar Vivadent, Schaan, Liechtenstein) were light cured with a Mylar strip. Fifteen specimens of each composite (6 mm in diameter and 3 mm in depth) were fabricated and randomly assigned to three groups. Specimens in each group were finished with a carbide bur (16 fluted) and three polishing systems (Astropol, Ivoclar Vivadent; Diagloss, Axis Dental, Irving, TX, USA; Sof-Lex, 3M, ESPE, St. Paul, MN, USA). The average surface roughness (Ra) and the mean peak spacing (Sm) were measured with a surface profilometer after polishing. Five tracings at different locations on each specimen were made. Data were analyzed by analysis of variance. For Astropol, Ra ranged from 0.10 to 0.15 microm and Sm ranged from 24 to 40 microm for the five composites; for Diagloss, Ra ranged from 0.24 to 0.34 microm and Sm from 38 to 74 pm; for Sof-Lex, Ra ranged from 0.06 to 0.10 microm and Sm ranged from 16 to 22 microm. Significant differences between materials and polishing systems were observed. Polishing systems had the most important role in determining the surface roughness of resin composites. Of the polished systems tested, Sof-Lex discs provided the lowest roughness for polishing microfilled and microhybrid composites, and the microfilled resin composite showed the lowest roughness.

Aim:To find and compare the qualitative and quantitative change in color and surface texture of feldspathic ceramic, pressable ceramic and ceramic used in computer-aided design/computer-aided manufacturing CAD/CAM after different surface treatments namely glazing, abrading and polishing. To compare the effectiveness of pearl finish polishing paste and Soflex polishing system used in the study.Setting and Design:In-vitro, comparative study.Materials and Methods:Disc-shaped feldsapathic, pressable, CAD/CAM ceramic specimens were fabricated. Surface roughness and color parameters Δ L*, Δa*, and Δ b* were measured before glazing, after glazing, after abrasion with 02 diamond bur and after polishing with two different polishing systems. Surface roughness was measured qualitatively using scanning electron microscopy and quantitatively using an optical profilometer. The value of color parameters was obtained using a colorimeter. Data were statistically analyzed with ANOVA.Statistical Analysis Used:SPSS software 20.0 version (IBM, New York, United states of America).Results:Unglazed feldspathic, pressable and CAD/CAM porcelain specimens showed a mean surface roughness value of 2.73 ± 0.38, 3.54 ± 1.42, and 3 ± 1.74 specimens. After glazing and polishing, the surface roughness values decreased. After abrasion, surface roughness values increased. Polishing did not alter the color along the red green axis and yellow blue axis.Conclusions:Abraded specimens of feldspathic, pressable and CAD/CAM after polishing using pearl finish polishing paste and Soflex disc became smoother than glazed specimens. When pearl finish polishing paste and Soflex discs were compared for their effectiveness the former appeared to be more superior but not to a significant level. Mechanically altering feldspathic, pressable, and porcelain used in CAD/CAM technology does not cause any change in shade.

In dentistry, interest in computer-aided design and computer-aided manufacturing (CAD/CAM) over traditional denture fabrication systems is increasing. However, few studies have compared the physiochemical and biological properties of different fabrication methods in regards to Candida albicans. C. albicans is the most common oral fungal pathogen, often related to dentures and elderly patients. Although various factors have been reported to influence C. albicans proliferation, conclusive evidence is lacking. Therefore, the aim of this study was to evaluate and compare the physicochemical properties of different denture materials in terms of surface roughness and C. albicans adhesion on the basis of polymerization methods and 3D print orientation. Four types of resin disks were prepared: autopolymerization, heat-activated polymerization, milling, and 3D printing. The surface roughness and water contact angle were measured via a confocal laser scanning microscopy (CLSM) and the sessile drop method. After C. albicans inoculation, microbial adhesion was measured by scanning electron microscope (SEM), a crystal violet assay, and an alcian blue assay. To further investigate the relationship between surface roughness and microbial adhesion, 3D-printed resin was fabricated at different build orientations. The resins were printed at 0, 45, and 90-degrees to modulate different surface roughness and simulate commonly used clinical settings. The same experimental set was used. The cell wall thickness of each group was measured via CLSM. For statistical analysis, one-way ANOVA and Tukey’s post hoc tests were performed. The 3D-printed group presented the greatest adhesion with the highest roughness parameters (Ra, Rdq). The milled group presented the lowest adhesion with the lowest surface roughness values. (p < 0.05) Among the 3D-printed samples with different build orientations, the 0-degree presented the lowest surface roughness and the lowest microbial adhesion. (p < 0.05) Microbial adhesion was less related to average roughness and more related to microroughness. The findings were further confirmed with SEM images with prominent grooves and layer lines with speckled patterns on 45 and 90-degree. The cell wall thickness showed no difference between the groups. (p > 0.05). Microbial adhesion is significantly affected by fabrication methods and build orientation. Milled and 0-degree 3D printed resins provide improved options with the potential to minimize Candida albicans adhesion with the lowest surface roughness. Due to their high surface roughness and microbial adhesion, 3D-printed resins with different printing orientations require meticulous polishing and regular cleansing. Despite the limitation of in vitro study, this study aims to provide a deeper understanding of surface morphology and microbial adhesion and provide clinical insights that milled and 0-degree printed resin are more favorable in minimizing C. albicans adhesion.

Objective: The purpose of this in vitro study was to determine the effect of different polishing methods applied on the surface roughness and color stability of leucite-reinforced feldspathic ceramic. Methods: The leucite-reinforced feldspathic ceramic slices were divided into 3 treatment groups and 2 control groups: 1 μm diamond polishing paste (P), silicon carbide polishing kit (PK), silicon carbide polishing kit followed by 1 μm diamond polishing paste, glazed control group, and roughened control group. The color changes (ΔE) of the specimens were recorded with a spectrophotometer. The surface roughness was evaluated by using an atomic force microscope (AFM) and scanning electron microscopy (SEM). The Ra and Rz values were statistically analyzed with Kruskal–Wallis and the Mann–Whitney U-tests. The Shapiro–Wilk, and one-way ANOVA tests were used for comparing ΔE. Results: Significant ΔE (color difference) values were found between groups after they were immersed in coffee solution (P &lt; .05). According to the Ra and Rz values, statistically significant difference was found between all treatments and the glazed and roughened control groups (P &lt; .05). Conclusion: Polishing techniques significantly affected the color of the leucite-reinforced feldspathic ceramic. After adjustment of the dental ceramic surface to remove the glaze, the polishing kit with paste application can be utilized. Cite this article as: Paken G. Polishing systems on surface roughness and the color stability of leucite-reinforced feldspathic ceramic. Essent Dent. 1(1):23-29..

To evaluate the effect of overglazing and two polishing procedures on flexural strength and quality and quantity of surface roughness of a monolithic lithium disilicate ceramic computer-aided design (CAD) after grinding. This in vitro study was conducted on 52 partially crystalized bar-shaped specimens (16 × 4 × 1.6 mm) of monolithic lithium disilicate ceramic. The specimens were wet polished with 600-, 800-, and 1200-grit silicon carbide papers for 15 seconds using a grinding/polishing machine at a speed of 300 rpm. Then, the specimens were crystalized and glaze-fired in one step simultaneously and randomly divided into four groups of 13: (I) Glazing group (control); (II) Grinding-glazing group, subjected to grinding with red band finishing diamond bur (46 μm) followed by glazing; (III) Grinding-D+Z group, subjected to grinding and then polishing by coarse, medium, and fine diamond rubber points (D+Z); and (IV) Grinding-OptraFine group, subjected to grinding and then polishing with a two-step diamond rubber polishing system followed by a final polishing step with an OptraFine HP brush and diamond polishing paste. The surface roughness (Ra and Rz) values (μm) were measured by a profilometer, and the mean values were compared using one-way ANOVA and Tamhane's test (post hoc comparison). One specimen of each group was evaluated under a scanning electron microscope (SEM) for surface topography. The three-point flexural strength values of the bars were measured using a universal testing machine at a 0.5 mm/min crosshead speed and recorded. The data were analyzed using one-way ANOVA and Tamhane's test (α = 0.05). Statistically significant differences were noted among the experimental groups for Ra, Rz (p < 0.0001), and flexural strength values (p < 0.009). The lowest Ra and Rz values were found in the grinding-OptraFine group (0.465 ± 0.153), which were significantly lower than those in glazing (p < 0.03) and grinding-glazing (p < 0.001) groups. The Ra and Rz values were not significantly different between the two polishing systems (p = 0.23 and p = 0.25, respectively). The highest flexural strength was found in the glazing group (283.350 ± 49.854 MPa) without significant differences compared to grinding-glazing (p = 0.98) and grinding-OptraFine groups (p = 0.86). The lowest flexural strength was found in grinding-D+Z group (225.070 ± 17.299), which was significantly different from the value in glazing (p < 0.03) and grinding-glazing (p < 0.04) groups. SEM analysis of polished surfaces revealed regular morphology with some striations. The OptraFine system created smoother and more uniform surfaces in terms of quantity (p < 0.03 for Ra, p < 0.01 for Rz) and quality of roughness compared to glazing. The flexural strength of lithium disilicate ceramic after polishing with the OptraFine system was similar to that after glazing (p = 0.86). Despite similar surface roughness after polishing with the two systems, the D+Z system reduced the flexural strength of ceramic (p < 0.03).

This study aimed to investigate the surface roughness, microhardness, and color changes of resin-based computer-aided design/computer-aided manufacturing (CAD/CAM) blocks and 3D-printed permanent resins in different beverages. Resin-based CAD/CAM blocks (Cerasmart 270 and Grandio Blocs) and 3D-printed permanent restorative resins (Crowntec and Permanent Crown) were used in this study. A total of 96 specimens were prepared from CAD/CAM blocks and 3D-printed permanent resins. The initial surface roughness, microhardness, and shade value of the specimens were measured. Then, the specimens prepared from each material were divided into three subgroups (n=8) and immersed in tea, coffee, and distilled water for 30 days. After the specimens were immersed in the beverages, the surface roughness, microhardness, and tone values were measured again. The data were statistically analyzed using a two-way analysis of variance test (p<0.05). No statistically significant difference was found in the surface roughness values of the resin-based CAD/CAM blocks and 3D-printed resins (p<0.05). Resin-based CAD/CAM blocks showed statistically significantly higher microhardness than 3D-printed permanent resins (p<0.05). Although the color changes in 3D-printed resins in tea and coffee were similar to those in resin-based CAD/CAM blocks on the first and seventh days, more color changes appeared in the 3D-printed resins after 30 days. The surface roughness and microhardness values of the specimens submerged in tea, coffee, and distilled water showed no statistically significant changes (p<0.05). Although the surface roughness of 3D-printed permanent resins was similar to that of resin-based CAD/CAM blocks, they had a lower microhardness value. Moreover, 3D-printed permanent resins showed more color changes in tea and coffee.