Three-dimensional surface profile analysis of different types of flowable restorative resins following different finishing protocols

AIM: The aim of this study was to investigate the surface roughness of different types of flowable restorative resins and compare the effectiveness of diamond finishing burs followed by aluminum oxide discs with aluminum oxide discs alone in producing smooth surfaces. METHODS AND MATERIALS: Twenty-four specimens (10 mm X 2 mm) for each flowable resin (flowable microhybrid composite, flowable liquid microhybrid composite, flowable compomer, and flowable ormocer) were fabricated in an acrylic mold and randomly assigned to three groups. In group I samples were left undisturbed after the removal of a Mylar strip (control). In group II samples were polished with diamond finishing burs, followed by aluminum oxide discs. In group III samples were finished with only aluminum oxide discs. The mean surface roughness (Ra, microm) was determined with 3-D non-contact interferometry. Data were subjected to one way analysis of variance (ANOVA), and post hoc comparison was accomplished using Tukey's HSD. RESULTS: Although significant differences in surface roughness (Ra) values were observed among the materials using a Mylar strip (control), no significant differences between restorative materials were found when all finishing/polishing methods were combined. For all flowable restorative resins tested, the Mylar strip produced surfaces smoother than those produced by a diamond finishing bur followed by a disc or by using discs alone. Surface roughness values were statistically similar for a diamond finishing bur followed by a disc and for disc treated surfaces within each material except for Dyract Flow, a flowable compomer. CONCLUSION: Although the surface roughness of flowable restorative resins differs among the types, this difference can be overcome with different finishing/polishing methods.     

The effects of porcelain polishing systems on the color and surface texture of feldspathic porcelain

STATEMENT OF PROBLEM: After the adjustment of glazed porcelain surfaces, the surfaces are roughened and must be reglazed or polished with different porcelain polishing systems to improve the esthetic appearance and strength of the porcelain restorations. PURPOSE: The purpose of this in vitro study was to compare the effect of different porcelain polishing methods on the color and surface texture of a feldspathic ceramic. MATERIAL AND METHODS: Ninety porcelain (Vitadur Alpha) discs (10 x 2 mm) were fabricated in a silicone mold and divided into 9 groups (n=10). A medium-grit diamond rotary cutting instrument was used to remove the glaze layer, and then the surface was polished using 1 of the 4 following polishing systems or a combination thereof: polishing paste (Ultra II), polishing stick (Diamond Stick), polishing wheel (CeraMaster), or an adjustment kit (Porcelain Adjustment Kit). No surface treatments were applied to the control group. Color measurements were made using a colorimeter (Minolta CR-321 ChromaMeter) according to the CIE L( *)a( *)b( *) color system. Color differences (DeltaE) between the control group and experimental groups were calculated. The acceptable level was chosen as 3.3 DeltaE units. Then the surface roughness (Ra) (microm) of the same specimens was evaluated using a profilometer. The data were statistically analyzed by 1-way analysis of variance and Tukey HSD tests (alpha=.05). To evaluate the effects of the polishing systems on the ceramic surfaces at a microscopic level, an additional 9 feldspathic ceramic specimens were prepared and polished to represent each of the 9 groups. These specimens were examined under a scanning electron microscope (SEM). RESULTS: Polishing techniques significantly affected the color of the feldspathic ceramic (P<.001). The DeltaE values ranged from 1.03 to 3.36. No significant differences were found within the adjustment kit groups or within the polishing wheel groups. All specimens polished with the various techniques showed significantly different Ra values than the control specimens (P<.001), except for the groups polished using the adjustment kit. The highest Ra and DeltaE values were obtained with the use of polishing paste and polishing stick alone (P<.001). The SEM observations demonstrated that the polishing techniques affected the smoothness of the porcelain surface. CONCLUSIONS: The evaluation of the polishing techniques showed that the use of an adjustment kit alone or preceding polishing paste or polishing stick application created surfaces as smooth as glazed specimens. The use of polishing paste alone did not improve the smoothness of the porcelain surface. The color differences of all groups were found to be at the acceptable level.     

Effect of different finishing and polishing techniques on the surface roughness of microfilled, hybrid and packable composite resins

This study examined the average surface roughness (Ra, microm) of 2 microfilled (Durafill and Perfection), 1 hybrid (Filtek Z250) and 2 packable composite resins (Surefil and Fill Magic), before (baseline) and after eight different finishing and polishing treatments. The surface roughness was assessed using a profilometer. Ten specimens of each composite resin were randomly subjected to one of the following finishing/polishing techniques: A -- carbide burs; B -- fine/extrafine diamond burs; C -- Sof-Lex aluminum oxide discs; D -- Super-Snap aluminum oxide discs; E -- rubber polishing points + fine/extrafine polishing pastes; F -- diamond burs + rubber polishing points + fine/extrafine polishing pastes; G -- diamond burs + Sof-Lex system; H -- diamond burs + Super-Snap system. Data were analyzed using two-way ANOVA and Tukey's HSD test. Significant differences (p<0.05) were detected among both the resins and the finishing/polishing techniques. For all resins, the use of diamond burs resulted in the greatest surface roughness (Ra: 0.69 to 1.44 microm). The lowest Ra means were obtained for the specimens treated with Sof-Lex discs (Ra: 0.11 to 0.25 microm). The Ra values of Durafill were lower than those of Perfection and Filtek Z250, and these in turn had lower Ra than the packable composite resins. Overall, the smoothest surfaces were obtained with the use the complete sequence of Sof-Lex discs. In areas that could not be reached by the aluminum oxide discs, the carbide burs and the association between rubber points and polishing pastes produced satisfactory surface smoothness for the packable and hybrid composite resins, respectively.     

Effect of polishing systems on the surface roughness of microhybrid composites

Purpose : This study was undertaken to examine the effect of three different polishing systems on surface roughness of five newly developed resin composites.
Materials and Methods : 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 micro-hybrid 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.
Results : For Astropol, Ra ranged from 0.10 to 0.15 um and Sm ranged from 24 to 40 um for the five composites; for Diagloss, Ra ranged from 0.24 to 0.34 um and Sm from 38 to 74 urn; for Sof-Lex, Ra ranged from 0.06 to 0.10 um and Sm ranged from 16 to 22 um. Significant differences between materials and polishing systems were observed. Polishing systems had the most important role in determining the surface roughness of resin composites.
CLINICAL SIGNIFICANCE
Of the polished systems tested, Sof-Lex discs provided the lowest roughness for polishing microfilled and microhybrid composites, and the microfilied resin composite showed the lowest roughness.     

EFFECTS OF POLISHING PROCEDURES ON COLOR STABILITY OF COMPOSITE RESINS

The purpose of this study was to investigate the effect of different polishing methods on color stability of posterior, universal and nanohybrid composite resin restorative materials upon exposure to a staining agent. Twenty-five specimens were prepared for each of 5 different composite resins (Filtek Z250, Filtek P60, Quadrant LC, Grandio and Filtek Supreme). Specimens were divided into 5 groups and different polishing procedures, including polishing discs (Pd), polishing discs then diamond polishing paste (PdP), polishing discs then a liquid polishing system (Biscover) (PdB), and combinations of these (PdPB) were used. Unpolished specimens served as the control (C). The specimens were stored for 48 h in a coffee solution. The color of all specimens was measured before and after exposure with a colorimeter, and total color change ∆E*) were calculated. The data were analyzed with a two-way ANOVA and the means were compared by Tukey HSD test (α=0.05). The lowest color difference was observed in the groups PdP and C, while the highest color difference was observed in PdPB, and PdB. When comparing the five different restorative materials, no significant difference was observed between FiltekP60 and FiltekZ250, and these materials demonstrated significantly less color change than Quadrant LC and the nanohybrid materials (Grandio, Filtek Supreme). The posterior (Filtek P60) and universal (Filtek Z250) composite resin restorative materials, which do not contain tetraethyleneglycol dimethacrylate (TEGDMA), were found to be less stainable than the nanohybrid (Grandio, Filtek Supreme) and universal (Quadrant LC) composite resins, which contain TEGDMA. The use of diamond polishing paste after polishing with polishing discs significantly decreased staining when compared to the groups that used polishing discs alone, for all restorative materials tested. The highest color change values were obtained for the specimens that were polished with the Biscover liquid polish system (PdB and PdPB groups).     

Effect ofartificial accelerated aging on color stability and surface roughness of indirect composites

Direct and indirect composite resins have different forms of polymerization. Some materials require a post-cure system associating light and heat enhancing clinical properties. This study assessed the changes in color and surface roughness of three indirect composite resins after accelerated aging. Twelve specimens (15 x 2 mm) were obtained for each tested material. Subsequently, the first measurements for roughness tests and colorimetric spectrophotometry (CIE L*a*b* scale) were performed. Specimens were subject to accelerated aging for 384 hours. New measurements were then performed to evaluate the resulting change. Accelerated aging produced color change and increased surface roughness in all composite resins. Solidex resin showed color changes above the clinically accepted value (DeltaE = 4.31 +/- 0.22), and roughness values (Ra = 0.088 +/- 0.008 microm) statistically lower than that of Artglass (Ra = 0.141 +/- 0.026 microm) and Targis (Ra = 0.124 +/- 0.02 microm) (p<0.001). All the indirect resins tested showed color change and increased roughness after accelerated aging. Solidex showed color stability above a quantitative level considered clinically acceptable and lower roughness values compared to the other resins.     

Effect of Additional Light Curing on Colour Stability of Composite Resins

AimThe objective of this study was to evaluate the effect of additional light curing on the colour stability of composite resins. Materials and methods: Four different composite resins—a nanofill, a nanohybrid, a microhybrid, and a bulk-fill composite resin—were tested. Eighty disc-shaped specimens were prepared from each material using either a quartz tungsten halogen or a light-emitting diode light source and were randomly divided into 2 groups according to the surface treatment: no polishing (nonpolished) or polishing with aluminum oxide discs (polished). Then additional light curing was applied to half of the specimens in each group. All specimens were immersed in coffee solution for 1 week. Colour was measured with a spectrophotometer at baseline and after 1 week of storage in coffee solution. Results: Statistically significant differences in colour stability were observed in the restorative materials according to the composition of composite resin, the polishing protocol, and additional light curing, whilst there were no significant differences according to the light source. Additional light curing reduced discolouration in all groups tested. Conclusions: Additional light curing may be beneficial after finishing and polishing in order to maintain aesthetics and increase the resistance of composite resins to discolouration.     

三种抛光系统对不同光固化复合树脂表面粗糙度影响的实验研究

目的：采用临床上常用的3种充填用光固化复合树脂,经过3种不同抛光系统处理后,观测其表面粗糙度的变化。方法：选择3种临床常用的前后牙通用光固化型复合树脂（FiltekZ250,SpectrumTPH,CHARISMA）,分别用3种抛光系统（sof—lex,Enhance,Super—Snap）修整、抛光,应用表面粗糙度仪测定其粗糙度,扫描电镜观察抛光后的表面形貌,然后对检测结果进行统计学分析。结果：3种复合树脂经不同抛光系统处理后,两因素析因设计方差分析检验树脂材料和抛光系统之间的相互关系,结果显示,二者之间具有交互作用。用Sof—lex处理FiltekZ250树脂可获得最低的Ra值,但Super-snap抛光套装处理各种复合树脂组间无显著差异,均能达到较低的粗糙度值。结论：（1）临床上常用的3种光固化复合树脂材料中,FiltekZ250与SpectrumTPH、CHARISMA相比有更好的抛光性能,可形成比较平整光滑的表面;（2）不同抛光系统和不同树脂之间存在交互作用,Sof-lex和Super—snap最适宜处理FiltekZ250树脂,抛光后的表面光滑;Super-snap抛光系统对3种不同复合树脂进行处理后,均能达到较低的粗糙度值,明显优于其它2种抛光系统。     

3种抛光方法对树脂表面粗糙度影响的比较

目的通过定性与定量分析比较3种抛光方法对3种不同树脂表面粗糙度的影响。方法将3种不同类型的树脂制作成15个直径为5mm,厚度为3mm的圆柱本样本,随机分为3组：Sof—Lex抛光碟组．Brilliant Gloss橡皮抛光尖组,One Gloss橡皮抛光尖组。抛光后用轮廓测定仪在样本测试面中心区测表面粗糙度（Ra）,然后每个小组中随机选取1个样本,采用原子力显微镜观察其表面微观形貌。结果Sof-Lex、One Gloss抛光后,3种不同树脂的Ra均值差异有统计学意义（P〈0．05）、单因素方差分析结果显示材料组之间、抛光方法组之间Ra均值差异均有统计学意义（P〈0．05）,且组内两两比较结果显示同种树脂3种抛光方法之间Ra均值差异有统计学意义（P〈0．05）：多因素方差分析结果显示材料类型和抛光方法均会影响树脂表面粗糙度,二者具有明显交互作用（P〈0．01）原子力显微镜观察结果显示Sof-Lex和BrilliantGloss抛光后树脂表面相对均一,OneGloss抛光后树脂表面有划痕、空穴、填料颗粒突出等结构。结论3种树脂之间、3种不同抛光方法之间Ra均值差异均存在统计学患义,抛光效果具有材料依赖性。     

Effect of finishing and polishing procedures on surface roughness, gloss and color of resin-based composites

PURPOSE: To evaluate the effects of different finishing and polishing procedures on surface roughness, gloss and color of five resin composites: two experimental microhybrid composites - FZ-Dentin (FZD) and FZ-Enamel (FZE), one commercial microhybrid composite - Esthet-X (EX), and two microfilled composites - Heliomolar (HM) and Renamel Microfill (RM). METHODS: Surface roughness, gloss and color of the disc-shaped specimens (10 mm in diameter and 2-mm thick) were measured as Mylar (baseline), 16-fluted carbide bur and polishing were completed. Sixteen specimens of each composite were randomized to four groups of four. After finishing with a 16-fluted finishing bur, each group was polished by a different system: 1. Astropol (A), 2. Sof-lex disc (S), 3. Po-Go (P), 4. Enhance (E). Average surface roughness (Ra) was measured with a profilometer. Gloss measurements were performed using small-area glossmeter, while color coordinate values were recorded using a spectrophotometer. A deltaE*ab< or =1 was considered to be the limit of perceptibility. RESULTS: The order of surface roughness ranked according to polishing system (for all five composites together) was: P < S < E < A. The order of surface roughness ranked according to composites was: RM < FZD < FZ < HM < EX. The order of gloss ranked according to polishing system (for all five composites together) was: P > E > A > S. The order of gloss values for the polished composites (for each of four polishing systems) was: RM > FZD > FZE > HM > EX. Fisher's PLSD intervals at the 0.05 level of significance for comparisons of means of surface roughness among five composites and four polishing systems were 0.01 and 0.01 microm, respectively. Fisher's PLSD intervals at the 0.05 level of significance for comparisons of means of gloss among five composites and four polishing systems were 6 and 5 GU, respectively. Color differences (deltaE*ab) among five composites and four polishing methods were found to range from 0.2 to 1.1.     

Comparison of flexural properties and surface roughness of nanohybrid and microhybrid dental composites

Recently introduced nanohybrid dental composites have promised a smoother surface finish and strength, comparable to that of microhybrid composites. This study compared the mechanical properties and surface finish of nanohybrid and microhybrid composites by measuring the flexural strength and modulus (four-point bend) and surface roughness after polishing (using atomic force microscopy) of six commercial dental composites (three nanohybrid, three microhybrid). Scanning electron microscopy (SEM) was used to qualitatively characterize filler morphology and size. The flexural strength and modulus were significantly higher among the microhybrid composites, while the nanohybrid composites exhibited significantly lower surface roughness. SEM characterization revealed differences in filler particle size and shape that could affect the flexural properties and surface roughness. Composites containing spherical filler particles exhibited higher flexural properties and lower roughness values compared to composites with irregular fillers. These results did not support the premise that nanohybrid composites offer similar mechanical properties to microhybrids in addition to a better surface finish.     

The effect of finishing and polishing procedures on the surface roughness of composite resin materials

AIMS: The aims of this study were to evaluate the effect of various finishing and polishing procedures on the surface roughness of six different composite resin materials (Artemis Enamel, TPH Spectrum, Filtek A-110, Filtek Supreme Enamel, Solitaire 2, and Filtek P-60) as well as to evaluate the effectiveness of the surface sealant application (BisCover) on the surface roughness after finishing and polishing procedures of tested composites. METHODS AND MATERIALS: Specimens (n=168) measuring 5 mm in diameter x 2 mm in thickness were fabricated in a plexiglass well covered with a Mylar strip using six composite resins. A control group of seven specimens of each material received no polishing after being cured under the Mylar strip. Twenty-one specimens for each composite were randomly divided among three finishing and polishing groups (n=7). Each group was polished using a different system: Carbide bur/Sof-Lex disc, Carbide bur/Enhance disc with polishing paste, and Carbide bur/Edenta composite finishing kit. The average surface roughness (Ra, microm) of the control and treated specimens were measured with the Mitutoyo Surftest-402 Surface Roughness tester. After a surface sealant (BisCover) was applied to all treated specimens, according to manufacturer's instructions, the average roughness (Ra) was measured again. Results were statistically analyzed using analysis of variance (ANOVA) and the post-hoc Scheffe's test at a p<0.05 significance level. RESULTS: Significant differences were found for the surface roughness (p<0.05) with interaction among composite resins and the finishing systems used (p<0.05). Enhance/Biscover finishing and polishing procedure surface was not significantly different from the Mylar strip surface groups (p>0.05). The Mylar strip group was not significantly different from the Sof-Lex/BisCover and Edenta/BisCover groups. The ranking of mean Ra values by materials was as follows: Filtek Supreme Enamel < Filtek A110 < TPH Spectrum < Artemis 相似文献   

The effect of two polishing pastes on the surface roughness of bis-acryl composite and methacrylate-based resins

STATEMENT OF PROBLEM: A highly polished restoration surface is necessary to promote a plaque-free environment. PURPOSE: The purpose of this study was to compare the surface roughness of 3 different bis-acryl composite-based and 3 different methyl methacrylate-based provisional crown and fixed partial denture resins after being polished with aluminum oxide and diamond paste. MATERIAL AND METHODS: Six different materials were used (Iso-Temp, Protemp II, Structer 2, Dentalon Plus, Tab 2000 Kerr, Temdent). A total of 180 specimens were fabricated: 30 specimens of each material using circular stainless steel molds 10 mm in diameter and 2 mm high. Each material was mixed and polymerized according to manufacturer's instructions. The bis-acryl composite specimens were polymerized with a laboratory light-initiating unit for 30 seconds on each side (400 to 525 nm, 75 W quartz-halogen light source). All specimens were kept in a water bath at 37 degrees C for 45 minutes. Ten specimens of each group were left as untreated controls, 10 specimens of each group were polished with the aluminum oxide paste (Composite Polish), and 10 specimens of each group were polished with the diamond paste (Insta glaze). Surface roughness was determined with a profilometer. The data were analyzed with one-way analysis of variance (Post Hoc Scheffe's S test) (P<.001). In addition, the profilometric evaluations photographic images were recorded with a scanning electron microscope to examine the surface roughness after polishing. RESULTS: The mean of the surface characteristics of the bis-acryl composites were 1.33 microm for aluminum oxide and 0.90 microm for diamond polishing paste; the mean of the results of the methyl methacrylate resins were 1 microm for aluminum oxide and 0.50 microm for diamond polishing paste. The difference between the mean values of bis-acryl resins groups and methacrylate-based resin groups were significant (P<.001). The difference between the subgroups of bis-acryl resins group (Iso-Temp, Protemp II, Structer 2) were not significant (P>.05). The difference between the subgroups of methacrylate-based resin group (Dentalon, Tab 2000, Temdent) were not significant (P>.05). CONCLUSION: Within the limitations of this study, single-phase polishing of the bis-acryl composites tested and the methacrylate resins tested with diamond-based paste produced a smoother surface than when polished with aluminum oxide paste.     

Porcelain refinishing with two different polishing systems after orthodontic debonding

OBJECTIVE: To compare the effects of two polishing systems on the surface roughness of three types of porcelain after orthodontic debonding. MATERIALS AND METHODS: A total of 90 porcelain discs were fabricated from feldspathic (n = 30), leucite-based (n = 30) or lithia disilicate-based (n = 30) ceramics. Ten samples in each group served as the control and received no surface treatment. The remaining 60 samples in three of the porcelain groups were bonded with lower incisor brackets and debonded using a testing machine in shear mode at a rate of 1 mm/minute crosshead speed. After debonding, the remaining adhesive resin was removed with a tungsten carbide bur. Then, two experimental subgroups (10 each) in each porcelain group were treated as follows: in the first subgroup, porcelain polishing wheel and polishing paste were applied, whereas in the second, polishing was performed using a series of Sof-Lex discs. The average surface roughness (Ra) of the all samples was evaluated using SPM/AFM (surface probe microscope/atomic force microscope). Data were statistically analyzed by analysis of variance for each porcelain material and polishing method. RESULTS: The polishing techniques affected surface roughness significantly. There were significant differences between the groups; higher Ra values were obtained with the use of porcelain polishing wheel and polishing paste (P < .001). CONCLUSION: The application of Sof-Lex discs can produce smoother porcelain surfaces than porcelain polishing wheel and polishing paste.     

Effects of polishing techniques on the surface roughness of acrylic denture base resins

STATEMENT OF PROBLEM: Rough surfaces of denture bases promote adhesion of microorganisms and plaque formation. It is therefore important to know how different polishing systems affect surface roughness of denture base acrylic resins. PURPOSE: The objective of this study was to compare the effects of 4 chairside polishing kits and 2 conventional laboratory techniques used for polishing 3 different acrylic denture base resins. MATERIAL AND METHODS: Using contact profilometric measurement, the surface texture of 54 specimens (15x30x3 mm) per acrylic material (autopolymerized ProBase Cold, heat-polymerized ProBase Hot, and injection heat-polymerized SR Ivocap plus) was studied before and after cutting with a tungsten carbide bur, and during and after chairside polishing with 4 polishing kits (Exa Technique, Acrylic Polisher HP blue, AcryPoint, Becht Polishing Cream), and after conventional polishing with 2 polishing systems (Universal Polishing Paste for Resins and Metals, Lesk Polishing Liquid). There were 9 specimens for each acrylic resin material and polishing method combination. Conventional lathe polishing with polishing paste served as the control. Mean average surface roughness (Ra) values of each specimen group were analyzed using a 2-way analysis of variance, the Scheffé post-hoc test, and paired t test (alpha=.05) with the Bonferroni adjustment. After testing the polished acrylic resin surfaces were evaluated under a scanning electron microscope. RESULTS: The highest mean average surface roughness (Ra=2.86+/-0.8 microm to 3.99+/-1.31 microm) was measured for surfaces finished with a tungsten carbide bur. The lowest surface roughness values (Ra=0.02+/-0.01 microm) were determined for acrylic resin specimens polished with a lathe and polishing paste. The Ra values of resin specimens after polishing with chairside silicone polishing kits ranged from 0.05+/-0.0 microm to 0.35+/-0.05 microm. Mean average Ra values of specimens polished with a polishing cream alone (Ra=1.01+/-0.17 microm to 1.68+/-0.47 microm) were significantly higher (P<.05) than those obtained with other polishing systems tested, which was confirmed by scanning electron microscope images of acrylic resin surfaces. Significant differences in mean average surface roughness were found between autopolymerizing and injected heat-polymerizing resin specimens. In addition, scanning electron microscopy revealed increased porosity of autopolymerizing resin specimens. CONCLUSIONS: Conventional laboratory polishing was found to produce the smoothest surface of denture base acrylic resin. Chairside silicone polishing kits produced a significantly smoother surface of acrylic resin than specimens polished with a tungsten carbide bur. The presence of large pores was characteristic for the autopolymerizing resin material.     

Evaluation of the wear resistance of new nanocomposite resin restorative materials

STATEMENT OF PROBLEM: The use of composite resins for the restoration of posterior teeth is popular because of the improved performance and appearance of these materials. Wear resistance continues to be of particular importance when restoring large occlusal areas in posterior teeth. PURPOSE: The purpose of this study was to evaluate the relative wear characteristics of 2 recently introduced nanofiller-based composite resins (Filtek Supreme, Premise) and compare them to the more traditional microhybrid (Point 4) and microfill (Heliomolar RO) materials that have been used for many years. MATERIAL AND METHODS: Six specimens (2 mm thick and 15 mm in diameter) of each material were subjected to 3-body wear tests using the Oregon Health Sciences University Oral Wear Simulator to produce abrasive wear and attrition for all specimens using human enamel as the opposing cusp. Profilometric tracings of the worn surfaces were used to determine the relative abrasive wear, attrition wear, and roughness (Ra) of the composite resin substrate. The mean diameter of the antagonist enamel wear facets was determined under a measuring microscope. Qualitative SEM analysis was also used to assess the surface appearance of the resulting enamel and composite resin wear facets. The data were analyzed by 1-way ANOVA and Tukey's multiple range post hoc test (alpha=.05). RESULTS: The results indicated that the composite resin type did not significantly affect the amount of measured attrition (P=.15) but did significantly affect abrasive wear (P=.02). The conventional microfill composite resin (Heliomolar RO) exhibited significantly less abrasive wear than the nanohybrid material (Premise). There was no significant difference in the average size of the opposing enamel wear facet generated by the different composite resin materials. Heliomolar RO resulted in a significantly rougher surface within the wear track than either nanohybrid composite resin (Premise) or microhybrid composite resin (Point 4) but was not significantly different than nanofilled composite resin (Filtek Supreme). CONCLUSIONS: The incorporation of nanofillers in 2 of the composite resin materials tested did not significantly improve their wear resistance or the amount of opposing cusp wear when compared to the traditional materials tested.     

不同抛光系统对金属烤瓷及复合树脂表面抛光的效果比较

目的:对比常见抛光系统对金属烤瓷及复合树脂表面的抛光效果,为口腔医师在临床工作中选择抛光系统提供参考.方法:按照常规技工操作制作镍铬合金烤瓷试片(2×4×6mm)36个,复合树脂试片(2×4×6mm)36个,共72个.用水砂纸逐级打磨表面到1000目后,将每种试片随机分成6组,每组6个.其中4组分别用四种抛光系统(DIAPOL,EAK,OptraFine,OptraFine+抛光膏)进行表面抛光处理,另两组分别为表面未抛光的空白对照和表面上釉的标准对照.用激光扫描粗糙度仪测量试片抛光前后及上釉后的表面粗糙度(Ra,μm),使用SPSS统计软件对各组粗糙度均值之间的差异进行单因素方差分析(one-way ANOVA,LSD)(α=0.05).并使用扫描电镜观察试片抛光前后及上釉后的表面形态.结果:所有试片经抛光后,表面粗糙度均有明显降低,但依然高于上釉组.金属烤瓷试片和复合树脂试片的未处理组、DIAPOL抛光组、EAK抛光组、OptraFine抛光组、OptraFine+抛光膏组、及上釉组的表面粗糙度(Ra)分别为0.687,0.497,0.378,0.262,0.207,0.170 μm及0.692,0.352,0.230,0.248,0.0783,0.0667μm.不同抛光系统抛光后的表面粗糙度间差异有统计学意义.结论:使用抛光系统抛光能显著降低金属烤瓷和复合树脂的表面粗糙度,但其表面光滑程度依然低于上釉后.OptraFine和抛光膏的联合使用对金属烤瓷和复合树脂表面的抛光效果优于其它抛光系统.     

抛光对三种复合树脂表面粗糙度影响的实验研究

目的：采用临床上常用的3种充填用光固化复合树脂进行抛光后对比研究,为临床医师选择适当的牙体充填材料提供指导。方法：选择3种临床常用的前后牙通用光固化型复合树脂（Filtek Z250,Spectrum TPH,CHARISMA）,均用Sof-lex抛光系统修整、抛光,扫描电镜观察抛光前和抛光后的表面形态,并用表面粗糙度仪测定其粗糙度,对检测结果进行统计学分析。结果：3种复合树脂经同一种抛光系统处理后粗糙度值均增大,不同复合树脂之间的两两比较显示存在显著性差异;Filtek Z250组表面粗糙度值（Surface Roughness,Ra）无论抛光前后,均较其他两种树脂的Ra值小。结论：用Sof-lex抛光系统修整、抛光,Filtek Z250在三种复合树脂中有较/最佳的抛光性能。     

抛光材料的粒度对复合树脂表面粗糙度及润湿性的影响

目的：比较抛光材料的粒度对3种复合树脂粗糙度及表面润湿性的影响。方法选择3种复合树脂材料,分别为Filtek Z100（A组）,Charisma（B组）和Clearfil AP-X（C组）,采用不同粒度的抛光材料（Sof-LexTM Extra Thin抛光彩碟）,随机分组抛光,然后,检测表面粗糙度（Ra）及接触角,并进行统计学分析。结果随抛光彩碟粒度减小,3种材料的Ra值均逐渐减小,精细粒度抛光组的接触角显著低于3个较粗粒度抛光组（P〈0.05）;3种材料在相同抛光材料粒度处理后,Ra显著不同（P〈0.05）：A组＜B组＜C组,同时,A组的接触角明显高于B组和C组（P〈0.05）。结论复合树脂的表面粗糙度及润湿性与材料种类和抛光材料的粒度相关。     

Surface roughness of packable composite resins polished with various systems

Purpose: The aim of this study was to evaluate the surface roughness of four packable composite resins, SureFil^TM (Dentsply, Petrópolis, Rio de Janeiro, Brazil), Prodigy Condensable^TM (Kerr Co., Orange, CA, USA), Filtek P60^TM (3M do Brasil, São Paulo, Brazil), and ALERT® (Jeneric/Pentron, Inc., Wallingford, CT, USA) and one microhybrid composite resin (Filtek Z250^TM, 3M do Brasil) after polishing with four finishing systems. Materials and Methods: Twenty specimens were made of each material (5 mm in diameter and 4 mm high) and were analyzed with a profilometer (Perthometer® S8P, Perthen, Mahr, Germany) to measure the mean surface roughness (Ra). The specimens were then divided into four groups according to the polishing system: group 1–Sof‐Lex^TM (3M do Brasil), group 2–Enhance^TM (Dentsply), group 3–Composite Finishing Kit (KG Sorensen, Barueri, São Paulo, Brazil), and group 4–Jiffy Polisher Cups® (Ultradent Products, Inc., South Jordan, UT, USA). The specimens were polished and then evaluated for Ra, and the data were subjected to analysis of variance, analysis of covariance, and Tukey's test (p= .05). Results: The mean Ra of SureFil polished with Sof‐Lex was significantly lower than that of KG points. Prodigy Condensable polished with Enhance showed a significantly less rough surface than when polished with Sof‐Lex. Filtek P60 did not exhibit a significant difference with the various polishing systems. For ALERT the lowest mean Ra was obtained with Sof‐Lex and the highest mean Ra with KG points. Regarding Filtek 2250, polishing with KG and Jiffy points resulted in a significantly lower mean Ra than when polished with Enhance. Conclusions: Packable composite resins display variable roughness depending on the polishing system used; the Sof‐Lex disks and Jiffy points resulted in the best Ra values for the majority of the materials tested.