Iatrogenic tooth abrasion comparisons among composite materials and finishing techniques

STATEMENT OF PROBLEM: Many different rotary instruments are available for shaping composite restorations. Whether use of these instruments causes undesirable iatrogenic abrasion of either the tooth surface or the composite restorative material is unknown. Assuming that damage occurs, which technique is least damaging is unknown. PURPOSE: This in vitro study quantified the loss of surface enamel and dentin surrounding Class V preparations during composite shaping and finishing procedures. The susceptibility of 2 types of composites to tooth abrasion was also examined. MATERIALS AND METHODS: Standardized Class V cavities were prepared at the amelodentinal junction of 36 human molar teeth. The teeth were randomly assigned to 6 groups of 6 teeth each. They were restored with either a low- or high-viscosity composite (Revolution or Prodigy Condensable, respectively) and finished with aluminum oxide disks, tungsten carbide burs, or ultrafine finishing diamond burs. The preparations were profiled before and after restoration. After each finishing procedure, morphological measurements of surface changes in the dentin and enamel were made and reported as volume (in cubic millimeters); maximum depth, mean maximum depth, and mean depth (in micrometers); and surface area (in square millimeters). The results were subjected to a 2-way analysis of variance for restorative material and finishing technique (P<.05). RESULTS: Aluminum oxide disks removed significantly less enamel than tungsten carbide burs or ultrafine finishing diamond burs, as measured by volume, maximum depth, mean maximum depth, mean depth, and surface area (P<.05). Conversely, aluminum oxide disks removed significantly greater dentin than either tungsten carbide burs or ultrafine finishing burs as measured by loss of volume, mean depth, and surface area (P<.05). There was no significant difference in the loss of surrounding tooth substance based on resin type (low or high viscosity). CONCLUSION: Within the limitations of this study, the 3 finishing systems tested resulted in varying degrees of iatrogenic abrasion of enamel and dentin. The composite material used had no significant effect on abrasion of the surrounding enamel or dentin.     

Rotary instrument finishing of microfilled and small-particle hybrid composite resins

Tungsten carbide burs operated at high speeds for trimming and finishing microfilled composite resins are contraindicated as they disrupt the composite resin surface. Diamond burs operated at low speeds do not disrupt the surface on microfilled and small-particle hybrid composite resins. High-speed finishing with carbide burs on small-particle (hybrid) composite resins produces not only a nondisrupted surface but leaves the surface flat and smooth--free from the characteristic striations and grooves left by diamond burs. These results suggest that the rotary instruments used to finish a composite resin must be selected in accordance with the type of composite resins used.     

Surface roughness and wettability of enamel and dentine surfaces prepared with different dental burs

The aim of dental adhesive restorations is to produce a long lasting union between the restoration and the tooth structure. This bond depends on many variables including the geometry of the preparation and the type of bonding agent or luting cement. It is therefore suggested that the topography of the tooth surface may influence the wettability and the bonding quality of adhesive systems. This study measured the surface roughness and wettability of enamel and dentine after preparation with different dental burs. The mesial and distal surfaces of 15 extracted sound human premolar teeth were prepared with a tungsten carbide crown bur, a diamond bur and a tungsten carbide finishing bur and finished in enamel or dentin, respectively. The prepared surfaces were analysed with a surface profilometer and scanning electron microscopy (SEM). The contact angle of distilled water on each of the prepared surfaces was used as the measure of wettability. The differences in average surface roughness (Ra) were significant between the rotary instrument groups, as revealed by a two-way ANOVA test. No differences were detected between enamel and dentine surfaces prepared with the same type of dental bur. The smoothest surfaces were those completed with tungsten carbide finishing burs. The diamond bur preparations were intermediate in the roughness assessment and the tungsten carbide crown burs gave the roughest surfaces. There were no significant differences in the contact angle measurements for the various groups. It was concluded that the surface roughness of enamel and dentine prepared by different rotary instruments had no significant influence on the wettability of distilled water on these surfaces.     

Effectiveness of diamond-impregnated felt wheels for polishing a hybrid composite

The effectiveness of diamond-impregnated felt wheels for polishing the surfaces of a fine-particle hybrid composite was studied in relation to different finishing methods. Standardised composite specimens were finished with one or a series of two or three finishing diamonds (particle size 30, 15 and 8 μm), one or two tungsten carbide finishing burs (12- and 30-fluted) or with a finishing diamond followed by a tungsten carbide bur. The final polishing of all specimens was done with the diamond-impregnated felt wheel Diafix α. Treatment with Sof-Lex discs after the use of a finishing diamond served as a polishing standard for comparison. Evaluation of the final surfaces was done with profilometry and by scanning electron microscopy. The profilometric results showed that the type of pretreatment was decisive for the quality of the final polishing. Nearly all surfaces polished by the diamond-impregnated felt wheels were smoother than those treated by the flexible discs (P<0.01). The lowest roughness data were recorded following a pretreatment with a finishing diamond and a tungsten carbide finishing bur. After appropriate pretreatment, the hybrid composite surface was sufficiently polished with the diamond-impregnated felt wheels.     

Effect of various grit burs on marginal integrity of resin composite restorations

The purpose of this study was to evaluate the generation of enamel cracks and gaps at the cavosurface margin of resin composite restorations using various burs. Saucer-shaped cavities with a bevel were prepared on mid-coronal buccal or lingual surfaces of extracted human molars using a regular-grit round diamond bur, a fine-grit diamond bur, a superfine-grit diamond bur or a six-bladed tungsten carbide bur with an air turbine handpiece. The enamel margin of the cavity in each group was observed by a light microscope. Cavities were restored with a self-etching adhesive and a light-cured composite resin. After thermocycling, enamel cracks and gaps at the cavosurface margins were observed and scored. Specimens were sectioned longitudinally in two halves, and the resin-cavity interface was observed by means of a light microscope. In cavity preparation, the regular-grid diamond bur and the tungsten carbide bur caused more cracks in the marginal enamel than other groups. From the surface and sectioned surface observation of restored teeth, the superfine-grit diamond bur generated fewer cracks and gaps than the other burs.     

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.     

Lubricating coolants for high-speed dental handpieces

Cutting studies were performed on tooth enamel, dental amalgam, and composite resin through use of carbide burs and diamond stones with three irrigants. A mixture of water, alcohol, and glycerol significantly increased the rate of material removal when enamel was cut with diamonds and when dental amalgam was cut with diamonds and carbide burs. In contrast, the rate of material removal for composite resin was significantly faster with use of carbide burs than diamond stones, and the irrigant improved the cutting action for carbide burs. The studies indicate that chemomechanical effects operate with dental substrates, but the effect varies with the material being cut and the cutting tool used. The chemomechanical effects observed here significantly improve the rate of material removal with diamond stones and carbide burs.     

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.     

Effects of various finishing systems on the surface roughness and staining susceptibility of packable composite resins.

OBJECTIVES: The purpose of the present study was to investigate the influence of various finishing systems on the surface roughness and staining of three packable resin composites and a conventional microhybrid one. METHODS: Three packable composites (Solitaire-Heraeus-Kulzer, ALERT-Jeneric-Pentron, SureFil-Dentsply) and a conventional microhybrid (Z250-3M-ESPE) were used. Composite specimens were prepared and polished with Poli I and Poli II aluminum oxide pastes, Ultralap diamond paste, Enhance finishing points, Politip rubber polishers, fine and extra fine diamond burs, and 30-blade tungsten carbide burs according to the manufacturers' instructions. The polished surfaces were evaluated with a profilometer, and then immersed in 2% methylene blue for 24h. Afterwards, the specimens were prepared for the spectrophotometric analysis. Results were statistically analyzed by ANOVA and Tukey test. RESULTS: Significant differences were found for the surface roughness and staining recorded, with interaction among composite resins and the finishing systems used. No correlation was found between surface roughness and staining susceptibility (p=0.5657). SIGNIFICANCE: For most of the polishing agents used, Z250 presented the smoothest surfaces and the least dye uptake. ALERT presented the roughest surfaces, and Solitaire, the highest dye concentration. The smoothest surfaces were not necessarily the most stain resistant. Staining is highly influenced by each composite monomer and filler composition.     

Clinically versus laboratory photocured facings.

Acrylic and composite resin facings may fracture or become detached from the metal framework. Insufficient retention, abrasion and trauma are among the causes of these phenomena. Clinical and laboratory techniques have been developed to fabricate facings by means of light-curing composite systems such as the Dentacolor (Kulzer, Inc.) system. The effect of different polishing methods, obtained in both techniques using the same material, was studied with SEM on samples. Finishing and polishing procedures were accomplished using fine finishing diamonds, diamond burs and sof-lex discs. Smooth and lustrous surfaces were obtained with finishing discs, in contrast to techniques using other finishing instruments. Little or no difference in surface texture was observed between samples finished by clinical and those finished by laboratory techniques.     

The nature and effects of composite finishing pastes

Specimens of composite resins, contoured and finished with a series of microfine diamonds, were finished with a selection of commercially available composite finishing pastes. The resulting surfaces were examined using scanning electron microscopy (SEM) and surface profilometry. Samples of the pastes were investigated using SEM and energy dispersive X-ray spectroscopy. All the paste systems employed an abrasive of similar composition and particle size. The selection of finishing pastes produced marked improvements of the surfaces of the composite resins. The small differences measured between the performances of the four finishing pastes included in this study could not be corroborated by SEM evaluation. Therefore, within the limitations of this study, there was little evidence to suggest that any one paste system was superior to the others. The results of this study indicate that commercially available composite resin finishing pastes of the type investigated may be used to improve the surface of all types of contemporary composite resins and may be of particular value in finishing the concave surfaces of restorations of composite resins following contouring and finishing with microfine diamond burs.     

Surface roughness of finished composite resins.

This study evaluated the results of polishing composite resin by using the following finishing and polishing techniques: Arkansas stone burs; eight-blade tungsten-carbide burs; diamond burs; aluminum-oxide disks; no polishing; and 12- and 30-blade tungsten-carbide burs. The results were compared to ascertain which technique delivers the smoothest surface. The study was done with 120 class V restorations on extracted human teeth distributed in two groups (I and II) of 60 restorations each. Group I teeth samples were filled with microfilled composite resin and Group II with a hybrid composite resin. Readings were made with a profilometer to evaluate the final polishing. The conclusions from the results of the study were that microfilled composite resins provided a better finish when treated with aluminum-oxide disks. These results were statistically significant (p < 0.001). When hybrid composites were used the control group recorded the lowest values.     

An evaluation of techniques for finishing margins of gold inlays.

The following conclusions on finishing margins of gold inlays were reached: 1. Instruments should be rotated perpendicular to the margin from gold to enamel. 2. Green stones produce rough surfaces that are not easily smoothed by finer instruments. 3. Hand burnishers and rubber points are not effective in producing gross marginal closure. 4. The best instruments for finishing occlusal margins are round steel burs, finishing burs, or white finishing stones. 5. When finishing occlusal margins, it is important to use an instrument small enough to gain access to the depth of grooves and fissures. 6. Proximal preparations made with a secondary flare yield castings with better "as cast" and finished margins than those preparations made with a butt joint. 7. The best instruments for finishing proximal margins are flexible paper discs. Usually, one fine sand or fine cuttle discs are necessary. 8. There is an indication that castings made from slightly overwaxed patterns can be finished to produce better margins than those made from patterns waxed exactly to the margins.     

Effects of Tooth Preparation Burs and Luting Cement Types on the Marginal Fit of Extracoronal Restorations

Purpose: Although surface roughness of axial walls could contribute to precision of a cast restoration, it is unclear how the roughness of tooth preparation affects marginal fit of the restoration in clinical practice. The purpose of this study was to describe the morphologic features of dentin surfaces prepared by common rotary instruments of similar shapes and to determine their effects on the marginal fit for complete cast crowns. Materials and Methods: Ninety crowns were cast for standardized complete crown tooth preparations. Diamond, tungsten carbide finishing, and crosscut carbide burs of similar shape were used (N = 30). The crowns in each group were subdivided into three groups (n = 10) for use with different luting cements: zinc phosphate cement (Fleck's), glass ionomer cement (Ketac‐Cem), and adhesive resin cement (Panavia 21). Marginal fit was measured with a light microscope in a plane parallel to the tooth surface before and after cementation between four pairs of index indentations placed at equal distances around the circumference of each specimen. Difference among groups was tested for statistical significance with analysis of variance (ANOVA) followed by Ryan‐Einot‐Gabriel‐Welsch Multiple Range Test (α= 0.05). Results: Analysis of measurements disclosed a statistically significant difference for burs used to finish tooth preparations (p < 0.001); however, luting cement measurements were not significantly different (p= 0.152). Also, the interaction effect was not significantly different (p= 0.685). For zinc phosphate cement, the highest marginal discrepancy value (100 ± 106 μm) was for tooth preparations refined with carbide burs, and the lowest discrepancy value (36 ± 30 μm) was for tooth preparations refined with finishing burs. For glass ionomer cement, the highest marginal discrepancy value (61 ± 47 μm) was for tooth preparations refined with carbide burs, and the lowest discrepancy value (33 ± 40 μm) was for tooth preparations refined with finishing burs. For adhesive resin cement, the highest marginal discrepancy value (88 ± 81 μm) was for tooth preparations refined with carbide burs, and the lowest discrepancy value (19 ± 17 μm) was for tooth preparations refined with finishing burs. Conclusions: Marginal fit of complete cast crowns is influenced by tooth preparation surface characteristics, regardless of the type of luting agent used for cementation. Tooth preparations refined with finishing burs may favor the placement of restorations with the smallest marginal discrepancies, regardless of the type of cement used.     

Finishing tooth-colored restorations in vitro: an index of surface alteration and finish-line destruction

Many studies have evaluated the surface characteristics of finishing and polishing instruments on different restorative materials using two- and three-dimensional models based on mechanical and optical techniques. However, only limited data are available regarding the problem of marginal causing detectable surface alterations such as scratches or grooves may also cause marginal damage. This study aimed to correlate the smooth-surface polishing efficacy of different instruments with their potential for destructive effects on restoration margins and enamel finish lines. An index was created that will help to evaluate future polishing instruments and select suitable ones for different clinical situations. A planar inlay system with a 100 microm wide defined gap was simulated in vitro. Pre-fabricated ceramic (n = 40) and composite blocks (n = 40) were connected to bovine enamel without luting material. After standardized pre-polishing, mean surface roughness and marginal quality were assessed using a profilometer and scanning electron microscopy (SEM). Enamel and restorative surfaces were colored, and subsequently prepared using one of 10 different finishing and polishing instruments. Four specimens per instrument and material were evaluated, resulting in eight interfaces for each test group. Surface roughness (Ra) and marginal quality (expressed as the percentage fracture-free margin) were measured and compared statistically using unpaired t-tests and two-way ANOVA, respectively. The level of significance was set at 0.05 Eight-micrometer diamond burs and 40-fluted tungsten carbide finishers produced smoother surfaces and less finishing-line destructions than the other instruments under evaluation. The index values developed will prove helpful in evaluating and selecting appropriate instruments.     

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.     

A New Carbide Finishing Bur for Bracket Debonding

BACKGROUND: The removal of residual bonding resin with rotary instruments after bracket debonding may damage the enamel surface. Conventional carbide burs may scratch the enamel due to the shape and sharpness of their blades. CARBIDE FINISHING BUR: A new carbide finishing bur with a slightly tapered shape, rounded tip and eight twisted blades has been developed. As a special feature the wedge angle of the blades has been enlarged to ca. 130-135 degrees by means of an oblique ground chamfer (relief angle ca. 0-5 degrees). The transition from head to shaft has been smoothed off with a safety chamfer. Overall, the cutting capacity has been reduced in the enamel, while the bur has remained sufficiently sharp within the adhesive resin. PROTOTYPE TESTING: For prototype testing, incisor brackets were bonded in vitro to 70 human incisors according to the standard clinical technique and removed after 7 days. Residual bonding resin was removed with conventional carbide burs and with gradually modified prototypes of the new finishing instrument respectively. The resulting enamel surfaces were evaluated by scanning electron microscopy. The specimens were then treated with a polishing paste and evaluated again. RESULTS: Conventional carbide burs remove not only residual bonding resin but also some enamel; scoring may occur. The newly developed finishing bur has been proven by morphological evaluation to be less aggressive in removing residual bonding resin after bracket debonding.     

Particle size and composition of composite dusts

Inhalation of respirable crystalline silica dusts (sized between 0.5 and 5.0 micrograms) causes silicosis. Crystalline silica fillers are used in some composites and fine dusts/aerosols generated during high-speed finishing of these materials may be regularly inhaled by clinical dental personnel. Due to the widespread use of composites, the potential of these dusts/aerosols for causing silicosis warrants concern. Six composites were polymerized, then abraded with diamond and carbide finishing burs to produce dusts in a manner simulating the clinical finishing of esthetic veneers. Dusts were collected on 0.8 micron filters using an air sampling pump. Six hundred particles of each dust sample were counted and measured using a light microscope. The respirable fraction of dust particles ranged between 57.2 and 85.7%. The diamond bur created more respirable particles than the carbide bur for each composite tested. The elemental composition of particles of each composite was determined by energy dispersive x-ray analysis. Silicon was detected in amounts ranging from 71-100%. Based on the composition and particle size distribution only, dusts generated during simulated finishing of composite resins containing quartz filler have the potential for causing silicosis in dental personnel.     

Effect of finishing time and techniques on marginal sealing ability of two composite restorative materials

STATEMENT OF PROBLEMS: Finishing of composites may adversely influence the sealing ability of direct adhesive restorations. PURPOSE: This study was conducted to determine whether finishing time and techniques under wet or dry conditions affect the microleakage of 2 types of class V composite restorations. MATERIAL AND METHODS: Eighty class V preparations were made in the buccal surfaces of noncarious molars with the occlusal margins ending in enamel and the gingival margins in dentin. Dental adhesive (Single Bond) was applied according to the manufacturer's instructions. Half of the preparations were restored with a microfilled composite (Silux Plus) and the other half with a hybrid composite (Filtek Z250). Within each major composite group (n = 40), 4 subgroups (n = 10) were established based on finishing technique (diamond finishing burs or aluminum oxide discs) and finishing time (immediate or delayed by 24 hours). The specimens were stored for 24 hours in 37 degrees C water, thermocycled for 250 cycles between 5 degrees C and 55 degrees C, immersed in 2% methylene blue solution for another 24 hours, and sectioned longitudinally. For both enamel and dentin margins, dye solution penetration at the tooth/composite interface was scored from 0 to 4 under stereoscopy at original magnification x 20. Data were analyzed with the Kruskal-Wallis test (P<.05). RESULTS: Significantly lower leakage scores were recorded for teeth restored with microfilled composite and finished under wet conditions after 24 hours (P<.01). No significant differences were found among the hybrid composite groups. CONCLUSION: For microfilled composite restorations on dentin margins, delayed wet finishing with diamond burs resulted in significantly lower microleakage scores than all other finishing protocols. Hybrid composite restorations had equivalent levels of microleakage regardless of the finishing method.