Surface geometry of four nanofiller and one hybrid composite after one-step and multiple-step polishing

This study assessed the surface quality of four nanoparticle composites and one hybrid composite after polishing with three different techniques. Nanocomposites Premise (KerrHawe), Tetric EvoCeram (Ivoclar Vivadent), Filtek Supreme (3M ESPE) and Ceram X Duo (Dentsply) and the hybrid composite Herculite XRV (KerrHawe) were selected. Sixty specimens 7x7 mm each were fabricated from these materials. After light curing, the specimens were treated with 600 grit sandpaper discs. Fifteen specimens of each composite were polished using flexible Sof-Lex discs (3M ESPE). The remaining 45 specimens of each material were prepared with three finishing protocols: a single 30 microm diamond (n=15), a sequence of a 30 microm and a 20 microm diamond (n=15) and a 30 microm diamond followed by a tungsten carbide finishing bur (n=15). Each series of 15 specimens was then subdivided into three groups of five and polished with the Astropol system (Ivoclar Vivadent), OptiShine brushes (KerrHawe) and the Enhance/PoGo system (Dentsply). Quantitative evaluation of surface roughness was done with the help of optical laser stylus profilometry. Average roughness (Ra) was calculated, and the effect of the materials, the finishing regimen and the polishing methods on surface roughness were analyzed by three-way and two-way Anova and Scheffé post-hoc tests. Qualitative evaluation of the surfaces was done with the help of scanning electron microscopy (PSEM 500, Phlipps). Photomicrographs were assessed with respect to surface quality in four gradings. Surface roughness after polishing was significantly influenced by three factors: composite material (p < 0.001), finishing protocol (p < 0.001) and polishing method (p < 0.001). There were strong interactions between the finishing and polishing methods (p < 0.001). Two of the nanocomposites were significantly smoother (p < or = 0.001), while the other two had a surface quality similar to that of a hybrid composite. Astropol achieved the lowest average roughness on all composites. Except for a combination of a 30 microm diamond and OptiShine brushes, which caused severe roughness, all the polishing methods produced surfaces that were significantly smoother than using the Sof-Lex discs.     

Surface geometry of three packable and one hybrid composite after polishing

This study evaluated the surface quality of four composite materials after polishing with six different polishing techniques. Eighty specimens were made using three packable composites (Definite/Degussa, SureFil/ Dentsply and Solitaire/Heraeus-Kulzer) and one hybrid composite (Herculite XRV/Kerr). Five specimens of each material were polished using flexible Sof-Lex discs. The remaining 75 specimens of each composite were prepared using three finishing protocols: a single 30 microm diamond (n = 25), two finishing diamonds (30/20 microm; n = 25) and a 30 microm diamond followed by a tungsten carbide finishing bur (n = 25). Final polishing of each of the three finishing groups was accomplished with SuperBuff, Diafix-oral, OneGloss, Astropol and HaWe Composite Polishers (n = 5, each). Surface roughness was evaluated quantitatively by laser-stylus profilometry. Average roughness (R(a)) was calculated; statistical analysis of the data was performed with two-way ANOVA and Scheffé post-hoc tests. The polished surfaces were examined qualitatively by SEM. The results showed significant effects on surface roughness from the different composites (p = 0.011) and polishing systems (p < 0.001). After polishing, the Solitaire surfaces (R(a) = 0.72 microm) were smoother than Definite (R(a) = 0.87 microm) and SureFil (R(a) = 0.89 microm) and significantly smoother than Herculite (R(a) = 0.92 microm; p = 0.011). Three of the polishing methods (SuperBuff, Diafix-oral and Astropol) achieved lower R(a)-values than Sof-Lex discs. The polishing quality of the one-step systems SuperBuff and Diafix-oral was strongly affected by the initial finishing protocol.     

Effect of finishing and polishing procedures on the surface roughness of new tooth-coloured restoratives

The purpose of this study was to evaluate the effect of various finishing and polishing procedures on the surface roughness of three new tooth-coloured restorative materials. The materials included a hybrid composite resin (Filtek Z250), a packable composite resin (Filtek P60), and an ormocer (organically modified ceramic) (Definite). Thirty-two specimens of each material were prepared and randomly divided into four finishing and polishing groups (n = 8): (i) diamond bur/silicone polishers, (ii) diamond bur/Sof-Lex discs, (iii) carbide bur/silicone polishers, (iv) carbide bur/Sof-Lex discs. Average surface roughness (Ra) in micrometers was measured with a Mitutoyo Surftest-402 Surface Roughness Tester and the data compared using anova, at P < or = 0.05. Surface topography was also assessed using the scanning electron microscope (s.e.m) from samples of each group. The Mylar strip produced the smoothest surface and finishing/polishing procedures; (ii) and (iv) were significantly smoother than (i) and (iii). The lowest variability in initial surface roughness between materials was also observed with ormocer group.     

Abrasive wear of resin composites as related to finishing and polishing procedures.

OBJECTIVES: Finishing and polishing procedures may cause topographical changes and introduce subsurface microcracks in dental composite restoratives. Since both of these effects may contribute toward the kinetics of wear, the purpose of this study was to assess and correlate the wear and surface roughness of minifilled and nanofilled composites finished and polished by different methods. METHODS: Specimens (n=10) made of a minifilled and a nanofilled composite were finished and polished with one of the four sequences: (1) tungsten carbide burs plus Al(2)O(3)-impregnated brush (CbBr) or (2) tungsten carbide burs plus diamond-impregnated cup (CbCp), (3) diamond burs plus brush (DmBr) or (4) diamond burs plus cup (DmCp). As a control, abrasive papers were used. After surface roughness had been quantified, three-body abrasion was simulated using the OHSU wear machine. The wear facets were then scanned to measure wear depth and post-testing roughness. All sets of data were subjected to ANOVA and Tukey's tests (alpha=0.05). Pearson's correlation test was applied to check for the existence of a relationship between pre-testing roughness and wear. RESULTS: Significantly smoother surfaces were attained with the sequences CbBr and CbCp, whereas DmCp yielded the roughest surface. Regardless of the finishing/polishing technique, the nanofilled composite exhibited the lowest pre-testing roughness and wear. There was no correlation between the surface roughness achieved after finishing/polishing procedures and wear (p=0.3899). SIGNIFICANCE: Nano-sized materials may have improved abrasive wear resistance over minifilled composites. The absence of correlation between wear and surface roughness produced by different finishing/polishing methods suggests that the latter negligibly influences material loss due to three-body abrasion.     

Effect of finishing and polishing procedures on the surface roughness of packable composites

This study examined the average surface roughness (Ra, micron) of three packable composites and one hybrid composite cured against mylar, before and after treatment with a fine finishing diamond bur, a resin finisher followed by fine and extrafine polishing paste, two silicone-based finishing and polishing systems, fine and super-fine aluminum-oxide polishing disks, a silicon carbide-impregnated polishing brush and a surface-penetrating composite sealant. Additionally, the Ra was examined for one of the packable composites before and after treatment with a finishing carbide, prior to the finishing and polishing procedures detailed above. The finishing diamond significantly increased the Ra for all composites (ALERT, SureFil, Solitaire and Z-100). The finishing carbide used with SureFil (SureFil + C) also increased the Ra; however, it also produced surfaces up to 3.5x smoother when compared to SureFil surfaces finished with the diamond. Overall, Sof-Lex Contouring and Polishing Discs were able to produce the smoothest surfaces, followed by the Jiffy Composite Polishing Cups, the Enhance Composite Finishing & Polishing System/Prisma-Gloss Composite Polishing Paste, the Diacomp Intra-Oral Composite Polishers and the Jiffy Composite Polishing Brushes, respectively. The smoothest surfaces were produced using Z-100, followed by SureFil + C (carbide finishing bur), Solitaire, SureFil and ALERT, respectively. In general, Protect-It Composite Surface Sealant had little effect on the Ra, except with ALERT, where a slight increase in Ra was observed.     

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.     

Evaluation of the Surface Roughness in Dental Ceramics Submitted to Different Finishing and Polishing Methods

Ceramic restorations have been widely used in dentistry. These restorations often require intraoral adjustment with diamond burs after their cementation causing increasing roughness of the ceramic surface. Consequently some finishing and polishing methods have been used to minimize this occurrence. The aim of this study is to evaluate the roughness of the ceramic surfaces submitted to different finishing and polishing methods. 144 specimens of VITAVM^®7, VM^®9 and VM^®13 (VITA Zahnfabrik) ceramics were fabricated and submitted to grinding using diamond burs. They were then divided into 15 groups (five of each ceramic type). Groups 1, 6 and 11—positive control (Glaze); Groups 2, 7 and 12—negative control (no polishing); Groups 3, 8 and 13—polished with abrasive rubbers (Edenta), felt disc and diamond polishing past; Groups 4, 9 and 14—polished with abrasive rubbers (Shofu), felt disc and diamond polishing past; Groups 5, 10 and 15—polished with aluminum oxide discs (Sof-Lex, 3M-ESPE), felt disc and diamond polishing paste. The roughness of the samples surfaces were measured using the rugosimeter Surfcorder SE 1700 and the data were submitted to statistical analysis using ANOVA and Tukey test at a level of significance of 5 %. There was statistically significance difference between the positive control groups and the other groups in all the ceramic types. Mechanical finishing and polishing methods were not able to provide a surface as smooth as the glazed surface for the tested ceramics. To assist dental practitioners to select the best finishing and polishing methods for the final adjustment of the ceramic restorations.     

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.     

Surface texture of four nanofilled and one hybrid composite after finishing

This study evaluated the surface geometry of four nanocomposites and 1 hybrid composite after finishing with rigid rotary instruments. Four nanofilled composites (Premise, KerrHawe; Tetric EvoCeram, Ivoclar Vivadent; Filtek Supreme, 3M ESPE; Ceram X Duo, Dentsply) and one hybrid composite (Herculite XRV, KerrHawe) were used for the study. Sixty specimens were made of each product, 7 x 7 mm in size. Fifteen specimens of each composite were subjected to the following finishing procedures: a 30 microm diamond (FM 1), a sequence of a 30 microm and a 20 microm diamond (FM 2) and a 30 microm diamond followed by a 12-fluted tungsten carbide finishing bur (FM 3). As a reference, 15 other specimens of each material were treated with Sof-Lex discs. Evaluation of the surfaces was done with laser-stylus profilometry. Roughness parameters were average roughness (Ra) and profile-length ratio (LR). Statistical analysis of the data was performed by two-way and one-way ANOVA and post-hoc tests by Scheffé. Additional qualitative assessment of the finished composite surfaces was done by scanning electron microscopy (SEM) at a tension of 25 kV. The composite materials and the finishing methods had a significant effect on surface roughness (p < 0.001 for Ra and LR). There were significant interactions between the materials and the finishing methods (p < 0.001 for Ra and LR). Compared to Herculite XRV, three of the nanocomposites were significantly smoother after finishing, according to FM 1-3 and after application of the Sof-Lex discs. Ceram X Duo and Herculite XRV had similar surface roughness in terms of Ra and LR. Compared to a single 30 microm diamond and a sequence of two diamonds (FM 2), significantly lower roughness values on all composites were achieved by using a 30 microm diamond followed by a tungsten carbide instrument (p < 0.001 for Ra and LR). Ra- and LR-values after FM 3 were similar or, in some cases, even lower than surface roughness measured after application of Sof-Lex discs. Evaluation by SEM revealed that the use of a 30 microm diamond caused detrimental surface alteration on all types of composites. A remarkable number of porosities were detected on 1 of the nanofilled composites.     

Analysis of surface roughness of glass-ionomer cements and compomer

The purpose of this study was to evaluate the surface roughness of two glass-ionomer cements (Vitremer and Chelon-Fil), and one compomer (Dyract) when submitted to different finishing/polishing procedures at different times. A hundred 80-sample discs were made of each material and randomly divided into six finishing/polishing groups: mylar strip (control); Sof-Lex discs; diamond burs; diamond burs/Sof-Lex discs; 30-fluted carbide bur; 30-fluted carbide bur/Sof-Lex discs. These procedures were carried out immediately after preparation of the samples, after 24 and 168 h. Average surface roughness (Ra) was measured with a profilometer and the values were compared using anova (P < 0.05). The smoothest surface for all materials was obtained when cured in contact with the mylar strip. All other tested products increased surface roughness of restorative materials, but Sof-lex discs lead to better results. The worst results were verified with diamond burs. The finishing/polishing procedures, when performed immediately, can improve the roughness of glass-ionomer cements but not of the compomer tested.     

不同邻面抛光方法对牙釉质表面粗糙度及表面形貌的影响

目的：评价4种邻面抛光方法对邻面釉质表面粗糙度及显微形貌的影响,为邻面抛光方法的选择提供依据。方法：选择21颗离体牙前磨牙,沿颊舌面中线纵剖后获得邻面釉质试件42枚,再用自凝塑料包埋,暴露邻面釉质,用浮石粉抛光,并超声清洗。将42个试样均分为6组,分别作如下处理：A组空白对照,不做处理;B组：阴性对照,采用标准金刚砂车针切磨触点及其周围釉质,切磨后不抛光;其余4组为实验组,经标准金刚砂车针切磨后分别采用以下方法抛光：C组：极细粒度金刚砂车针抛光;D组：裂钻抛光;E组：矽粒子抛光;F组：彩虹抛光条抛光。之后用粗糙度仪测定釉面粗糙度,并进行扫描电镜观察。结果：标准金刚砂车针切磨后粗糙度大幅度增加（P〈0.05）,釉质表面发生明显条形凹陷性缺损;经4种方法抛光后,釉质表面粗糙度均有显著下降（P〈0.05）,显微形貌均较阴性组光滑,其中矽粒子抛光组可达到较空白对照组更为光滑的表面。结论：实验涉及的4种不同邻面抛光方法均有助于降低釉质切磨区域的表面粗糙度,但抛光效果存在差异;采用矽粒子抛光可完全抵消牙体预备时旋转器械对邻牙邻面的切磨作用,获得最为光滑的釉质表面。     

Finishing and polishing of indirect composite and ceramic inlays in-vivo: occlusal surfaces

This study evaluated occlusal margins and surfaces of composite and ceramic inlays after finishing and polishing in vivo. Eighty Class II cavities surrounded by enamel were prepared by two experienced dentists. Forty cavities were restored with indirect microhybrid composite inlays (Tetric), the balance were treated with heat-pressed glass ceramic inlays (IPS Empress). Using a rubber dam, the inlays were inserted adhesively with a dual curing composite of high viscosity (Variolink Ultra). Finishing was performed with the sequence of a 30 microm and 20 microm diamond (finishing method FM 1) or a 30 microm diamond followed by a tungsten carbide finishing bur (FM 2). The composite inlays were divided into four groups of 10 that were finished and polished according to the following protocol: (A) FM 2/Diafix-oral, (B) FM 2/MPS gel, (C) FM 1/Diafix-oral, (D) FM 1/MPS gel. Ten ceramic inlays each were treated as follows: (E) FM 2/MPS gel, (F) FM 1/MPS gel, (G) FM 2/ Diamond polisher, (H) FM 1/Ceramiste silicon polishers. After polishing, replicas of the restorations were fabricated. The replicas were examined by SEM with respect to margin quality (portion of continuous margins, overhangs, submargination and marginal imperfections). Furthermore, surface properties were evaluated qualitatively, which included assessing roundness of the contours in three grades (smooth rounding, few edged contours or predominantly edged contours) and evaluation of the surface roughness (smooth and homogeneous surface, minor roughness or severe roughness). Quantitative analysis of the occlusal composite and ceramic inlay margins showed that 52.2%-84.6% were rated as continuous, 0%-14.0% were characterized by overhangs and 0.7%-10.8% by submargination. A portion of 4.9%-18.1% margins revealed imperfections. The amount of marginal gap formation was negligible. Composite and ceramic inlays showed a similar behavior with respect to marginal quality after finishing and polishing. Overall, there were no significant differences among the four methods applied to composite and the four methods used on ceramic inlays with respect to margin quality. The use of a 30 microm diamond followed by a tungsten carbide bur on composite and ceramic inlays resulted in a significantly larger portion of continuous margins compared to finishing with two diamonds (p=0.049). Qualitative evaluation of composite and ceramic inlays revealed that 50%-80% of the occlusal surfaces were characterized by few edged contours and 10%-50% by smooth rounding. With respect to roughness, smooth surfaces prevailed both on composite (67.5%-80.0%) and ceramic inlays (64.5%-77.3%). Overall, no significant differences were detectable between the methods for finishing and polishing composite inlays and the methods applied to ceramic restorations with respect to roundness of contours and surface roughness.     

Effectiveness of Reciprocal-Action Instrumentation for Polishing Composite Resin: An In Vitro Study

This in vitro study investigates the use of reciprocal-action instrumentation for polishing composite resin restorative materials. Electron photomicrographs were made of surfaces of a microfilled and a hybrid composite resin restorative material polished by various reciprocal-action polishing procedures, including several types of polishing pastes used with nonabrasive plastic tips. The best polish on the microfilled composite resin restorative material tested was produced by ending with 3-μ diamond polishing paste. The best polish on the hybrid composite resin restorative material tested was produced by ending with 0.5-μ diamond polishing paste. The surfaces produced were comparable to those produced by polishing discs.     

Surface roughness of resin composite prepared by single-use and multi-use diamonds

PURPOSE: To compare the surface roughness of a resin composite caused by two 30- and 40-microm, multi-use finishing diamonds with two 30- and 40-microm, single-use finishing diamonds of comparable grit size before and after steam sterilization. METHODS: Resin composite specimens 6 mm in diameter and 3 mm in depth were light cured. Surface roughness (Ra, microm) of surfaces formed by Mylar, after finishing with a bur, and after polishing with fine and superfine aluminum oxide disks was measured for the as-received and after sterilization conditions with a surface profilometer. RESULTS: Ra of Mylar surfaces (baseline) ranged from 0.02-0.05 microm. Ra of surfaces prepared with 30-microm diamond burs ranged from 1.42-1.90 microm. Ra of surfaces prepared with 40-microm diamond burs ranged from 2.22-2.42 microm. Ra of surfaces polished sequentially with fine and superfine aluminum oxide disks ranged from 0.07-0.11 microm in the as-received condition and from 0.12-0.14 microm in the sterilized condition. Sterilization and reuse of all types of diamond finishing burs resulted in equal or rougher resin composite surfaces after final polish when compared to final polish surfaces that were initially finished with as-received diamonds. CLINICAL SIGNIFICANCE: Surface roughness of a resin composite prepared with single- and multi-use diamond finishing burs was equivalent when compared at the final polish.     

The effect of polishing techniques on the surface roughness and color change of composite resins

STATEMENT OF PROBLEM: Surface characteristics may affect the color change and surface roughness of composite resins. PURPOSE: This study evaluated the surface roughness and color change of a hybrid, a microhybrid, and a nanohybrid composite resin polished with the use of polishing discs, wheels, and a glaze material. MATERIAL AND METHODS: Fifty discs (10 x 2 mm) were fabricated for each composite resin (nanohybrid, Grandio; microhybrid, Filtek Z250; hybrid, Quadrant Universal LC) for a total of 150 discs, prepared using polyester strips and divided into 5 groups of 10. One of the groups served as control (C) and had no surface treatment (n=10). The specimens of the experimental groups were ground with 1000-grit silicon carbide paper. In 4 experimental groups (n=10), specimen surfaces were polished with polishing discs (D) (Sof-Lex), with polishing wheels (W) (Astropol), with polishing discs preceding the glaze application (DG) (Biscover), or with polishing wheels preceding the glaze application (WG), respectively. Color was assessed using a small area colorimeter. The color differences (DeltaE) values between the specimens of Group C and the experimental groups were calculated, and the data were compared using 2-way analysis of variance (ANOVA) (alpha=.05). Subsequently, the surface roughness (Ra) of the specimens was evaluated using a profilometer, and the data were analyzed by 2-way ANOVA followed by a Tukey multiple comparisons test (alpha=.05). RESULTS: The polishing technique and type of composite resin significantly affected the Ra and DeltaE values of the composite resins (P<.001). While the use of polishing wheels produced the highest Ra values when compared to the other polishing techniques (P<.001), the nanohybrid composite resin showed the lowest Ra values compared to the other composite resins in the control groups (P<.001). All of the nanohybrid and microhybrid composite resin groups were found to be significantly different from each other in terms of color difference (P<.001). CONCLUSION: The highest Ra values were obtained with hybrid composite resins due to the size of the filler particles that were exposed after polishing. Although the smoothest surfaces were obtained with polyester strips, the use of glaze material after polishing discs or polishing wheels resulted in significantly lower Ra and DeltaE values than the use of the latter alone. The glaze appears to fill the structural microdefects and provide a more uniform, regular surface.     

Tooth color change due to different etching and debonding procedures

Objectives:To compare the effects of different etching techniques, 12–, 24–bladed tungsten carbide burs, and polishing discs on tooth color changes during orthodontic treatment.Materials and Methods:59 individuals (mean age: 15.20 ± 1.59 years) were divided into four groups: 37% phosphoric acid and adhesive primer was used in Groups I and II whereas self–etch primer was used in Groups III and IV for enamel preparation. After orthodontic treatment, residual adhesives were cleaned with 12–bladed tungsten carbide burs in Groups I and III, while 24–bladed tungsten carbide burs were used in Groups II and IV. All teeth were polished with medium and fine Sof–Lex XT discs (3M ESPE, St Paul, Minnesota). Color measurements were taken from upper incisors and canines at pretreatment (T0), after cleaning with tungsten carbide burs (T1) and polishing with discs (T2). Wilcoxon test was used for evaluation of L*, a*, b* changes and Kruskal–Wallis for intergroup comparison of color changes.Results:L*, a*, b* values, except a* at Groups I, II, IV, and b* at Group III, changed significantly (P < .05). Groups III and IV showed significantly different color alterations from T0 to T1 (P < .05). After polishing, tooth color alterations were not significantly different among the groups.Conclusions:In self–etch bonding groups, a 12–bladed tungsten carbide bur caused less color change than the 24–bladed tungsten carbide bur. Orthodontic treatment resulted with visible and clinically unacceptable tooth color alterations regardless of the enamel preparation and clean–up techniques. Polishing reduced the effect of tungsten carbide burs, but did not affect the total influence of orthodontic treatment on the tooth color.     

Effectiveness of reciprocal-action instrumentation for polishing composite resin: an in vitro study.

This in vitro study investigates the use of reciprocal-action instrumentation for polishing composite resin restorative materials. Electron photomicrographs were made of surfaces of a microfilled and a hybrid composite resin restorative material polished by various reciprocal-action polishing procedures, including several types of polishing pastes used with nonabrasive plastic tips. The best polish on the microfilled composite resin restorative material tested was produced by ending with 3-mu diamond polishing paste. The best polish on the hybrid composite resin restorative material tested was produced by ending with 0.5-mu diamond polishing paste. The surfaces produced were comparable to those produced by polishing discs.     

Polishing methods of an alumina-reinforced feldspar ceramic

The purpose of this study was to test the hypothesis that mechanical polishing methods of ceramic surfaces allow similar superficial roughness to that of glazed surfaces. Twenty-five Vitadur Alpha ceramic discs (5 mm x 2 mm) were prepared according to the manufacturer's specifications. All specimens were glazed and randomly assigned to 5 groups (n=5), according to finishing and polishing protocols: G1: glazed (control); G2: diamond bur finishing; G3: G2 + silicon rubber tip polishing; G4: G3 + felt disc/diamond polishing paste; G5: G3 + felt disc impregnated with fine-particle diamond paste. Next, surface roughness means (Ra - microm) were calculated. Qualitative analysis was made by scanning electron microscopy. Surface roughness data were submitted to ANOVA and Tukey's test at 5% significance level. G1 and G4 were statistically similar (p>0.05). G2 presented the highest roughness means (p<0.05) followed by groups G3, G5, G4 and G1 in a decreasing order. The hypothesis was partially confirmed as only the mechanical polishing (G4) produced similar superficial roughness to that of surface glazing, although finishing and polishing are technically critical procedures.     

Surface treatment of mercury-free alloys.

Finishing and polishing methods were examined for two metallic direct restorative materials being proposed as possible alternatives to amalgam, namely a gallium alloy and a consolidated silver alloy. The polished surfaces were compared to a conventional spherical amalgam (Tytin). After initial surface treatment with a 12-fluted tungsten carbide bur in a high-speed dental hand-piece, three polishing methods were evaluated: slow-speed polishing burs, rubber polishing points, and polishing disks (Sof-Lex). Each of these methods was followed by an additional surface treatment in which a pumice-flour/water slurry was applied with a rotary brush and a final surface treatment with a zinc-oxide/ethanol slurry that was applied with rotary rubber cups. The surface roughness was evaluated by profilometric measurements and light microscopy. The results showed that the smoothest surfaces for all metals were achieved with rotary finishing and polishing disks. Using the rubber points resulted in surfaces that were statistically similar to the disk-polished surfaces on all three materials. The polished surface of gallium alloy was consistently slightly rougher than that of amalgam. The consolidated silver also presented a consistently rougher surface than did amalgam, although these differences were not statistically significant. The additional polishing with pumice and zinc oxide improved the luster, but did not significantly improve the measured surface smoothness in any of the restorative materials studied.     

Porcelain surface roughness, color and gloss changes after orthodontic bonding

The purpose of this study was to evaluate the alteration in surface characteristics after orthodontic debonding of two types of porcelain systems commonly used in prosthetic dentistry. For this purpose, porcelain specimens were fabricated from low-fusing (n = 20) and high-fusing (n = 20) porcelain. The baseline surface roughness, color, and gloss were evaluated using profilometry, color shade index, and gloss study. All specimens were bonded with brackets and debonded using a testing machine at a rate of 0.1 mm/minute crosshead speed. The porcelain surfaces were polished using a 12-fluted carbide composite removal bur (low-fusing, n = 20; high-fusing, n = 20). In addition, half of each porcelain group was further polished using a series of Sof-Lex discs (low-fusing, n = 10; high-fusing, n = 10). The postdebond porcelain surface characteristics roughness, color, and gloss were reevaluated and compared with baseline measurements. The results were analyzed with two-way analysis of variance and Tukey multiple comparisons test, with porcelain type (low-fusing or high-fusing) and polishing protocol (carbide bur or carbide bur and discs) serving as discriminate variables at alpha = 0.05 level of significance. Bonding and debonding increased all roughness parameters tested; however, no change was revealed between the two polishing protocols. Similarly, gloss and color index changes were significantly altered after resin grinding, regardless of the polishing method used. No difference was identified between the two porcelain types with respect to roughness, color index, or gloss. Orthodontic bonding alters the porcelain surfaces, and postdebond polishing does not restore the surface to the prebond state.