Profilometric analysis of two composite resins' surface repolished after tooth brush abrasion with three polishing systems

Surface roughness and microhardness evaluation of composite resin restorations subjected to three different polishing systems immediately and after 24 h: An in vitro study

Background

Finishing and polishing of composite resin restorations can be considered two different procedures or two steps of a single procedure. During the finishing procedure, contours are corrected while margins and irregularities are smoothened. The polishing procedures result in the production of a smooth and lustrous finish. Consensus regarding the correct timing for initiating the steps of finishing and polishing after the curing of the composite resins is divided. Some authors support immediate finishing and polishing while other authors support delaying the finishing and polishing procedures.

Aim

The aim of this study is to evaluate the surface roughness and microhardness of composite resin restoration subjected to finishing and three different polishing systems immediately and after 24 h.

Materials and Method

Eighty composite resin samples were prepared. A Teflon mold was made which was customized for this study having dimensions of 10-mm diameter and 2-mm depth. For the first group of specimens, Group I (n = 20) the composite resin surface was covered with Mylar Strips which acted as control. The other specimens (n = 60) were prepared without the use of a Mylar strip, followed by curing. For all the samples, curing was done with a light-emitting diode for 40 s each. Eighty light-cured samples were divided equally into 4 groups, each group containing 20 samples (n = 20). Out of the 20 samples, in the second, third, and fourth groups, (Kenda C. G. I., Shofu Super-snap X-Treme, and Eve Diacomp Plus Twist) 10 samples were finished and polished immediately after curing and the other 10 samples were finished and polished after 24 h of curing. The samples in Groups II, III, and IV were subjected to finishing by a 12-fluted tungsten carbide bur and were polished according to the respective manufacturer's instructions. The samples were then subjected to quantitative analysis of surface roughness by a noncontact three-dimensional optical profilometer (Bruker GT-Q; Ettlingen, Germany) and qualitative analysis of surface roughness by a scanning electron microscope (Zeiss EVO 18 Special Edition; Carl-Zeiss-Strasse; Oberkochen Germany) at ×10,000 magnification. The samples were also subjected to Vickers microhardness measurement using a microhardness tester (Leica VMHT 001; Walter UHL GmbH, Germany) under 100 g load over 10 s.

Conclusion

A. For surface roughness: The samples cured under Mylar strips gave the least surface roughness values (0.25 ± 0.032). Immediate finishing and polishing procedures led to statistically less surface roughness than when finishing and polishing procedures were performed after a delay of 24 h for all polishing systems used B. For microhardness: The samples cured under Mylar strips gave the least microhardness values (57.1 ± 2.03). Delayed finishing and polishing increased microhardness values in all finishing and polishing systems used. Different polishing systems did not have any significant effect on the microhardness values in immediate and delayed finishing and polishing groups.

Influence of Surface Type with Coffee Immersion on Surface Topography and Optical and Mechanical Properties of Selected Ceramic Materials

BACKGROUND The aim of this study was to assess and compare the effect of surface type (glazed or polished) with coffee immersion and aging on surface topography (Ra), optical properties (TP, OP), and mechanical properties (fracture forces and modes) of zirconia-reinforced lithium silicate (Vita Suprinity), hybrid polymer-infiltrated-feldspathic ceramic network material (Vita Enamic), and leucite-containing feldspathic glass (Vitablocs® Mark II) made by computer-aided design and computer-aided manufactured (CAD/CAM) ceramic materials. MATERIAL AND METHODS Fifty-four specimens were assembled out of the above 3 CAD/CAMs ceramic materials. Each group was divided into glazed or polished surfaces, having 9 specimens of every type and stained in coffee for 15 days. Ra and color of specimens in the form of TP and OP were recorded before and after immersion in staining material. Fracture forces and modes were analyzed after the 90-day aging. Data were analyzed using ANOVA, then post hoc analysis and Bonferroni tests. RESULTS Our study found significant differences in Ra, TP, and Op before and after coffee immersion between glazed and polished specimens, with higher values in the polished surfaces among the 3 ceramic materials. The highest values of fracture resistance were noted in Vita Suprinity, and Vita Enamic had the lowest values, without significant differences among groups. CONCLUSIONS Most of the TP and OP values were in acceptable clinical range, and Vita Suprinity had superior TP than the other groups. Reparable fracture types were observed in Vita Suprinity, whereas semi-reparable and non-reparable were predominant in other groups.

Effect of erosive challenge with HCl on restorative materials

OBJECTIVE

Investigate the effect of erosive challenge with hydrochloric acid (HCl) on the surface of five different restorative materials.

MATERIAL AND METHODS

Ten plates of five restorative materials (Admira Fusion, Activa BioActive-Restorative, Charisma, Equia Forte HT Fil/EF, Filtek Universal Restorative/FU) were obtained. Half of the plate surfaces was covered with an adhesive tape, creating a control area, and the other side was submitted to the HCl (0.06 M HCl; pH 1.2; at 37 °C; for 30 h). Plates with control and HCl-treated areas were analyzed regarding the surface roughness (Sa), roughness profile (Rv), surface loss (SL), microhardness (MI), and gloss (GL) (n = 10). Surface morphology was analyzed by SEM and chemical elements were identified by EDX (n = 5). Data were evaluated by ANOVA and Tukey's test (α = 0.05).

RESULTS

Most materials were not affected by HCl. FU showed the lowest Sa and Rv, and the highest GL after HCl. On the other hand, EF presented the highest Sa, Rv, and SL, and the lowest GL. The MI of materials was not changed after HCl. Topographical and chemical alterations were observed after HCl only for EF.

CONCLUSIONS

The composites showed minor surface changes after HCl, which was not observed for the glass ionomer cement (EF). FU presented the best performance regarding the parameters evaluated.

CLINICAL RELEVANCE

The effects of erosive challenge with HCl on composites were minimal, while the glass ionomer cements might not be indicated as restorative material for patients with gastroesophageal reflux disease.

Development and maintenance of surface gloss of dental composites after polishing and brushing: Review of the literature

OBJECTIVE

To describe the effect of the composites' composition to produce high surface smoothness/gloss using finishers/polishers, and to assess maintained smoothness/gloss under toothbrush abrasion.

MATERIALS AND METHODS

PubMed papers published from January 01, 2000 to September 01, 2021 were included, and keywords used were: filler particle size, shape, amount of dental composites; finishing/polishing, gloss/roughness, and toothbrush abrasion of composites. Seventy-five in-vitro studies were included in this literature review. Forty-six articles assessed filler particle size/composition/shape and distribution to obtain high gloss/smoothness on different formulations; and the finishers/polishers effect on these materials. Twenty-nine papers assessed toothbrush abrasion of composites.

RESULTS

Suprananofill/nanofill/microfills typically showed the smoothest and glossiest surfaces compared to nanohybrid, microhybrid and hybrid composites. Microfill (0.04-0.07 μm, 71-88 GU); suprananofill (0.001-0.8 μm, 52-92 GU), microhybrids (0.05-0.35 μm, 35-95 GU) and nanohybrids (0.05-0.21 μm, 66-97 GU). Composites with small, spherical particles tend to show smoother, glossier surfaces and more wear resistant compared to resin composites with larger or irregular particles. Several studies showed higher roughness and reduced gloss after toothbrush abrasion.

CONCLUSIONS

Within the limitations of this study, suprananofill/nanofill/microfill composites tended to show the smoothest/glossiest surfaces due to smaller particle size. Composites with small, spherical particles tended to show smoother/glossier surfaces. Overall, toothbrush abrasion showed higher surface roughness and reduced gloss.

CLINICAL SIGNIFICANCE

Suprananofills/nanofills/microfills had good polishability and polish retention due to their smaller particle size. The effectiveness of a polishing system is material-dependent. In general, Enhance-PoGo, Sof-Lex discs, and Sof-Lex Spiral wheels showed similar level of smoothness.

Development of Newly Formulated Nanoalumina-/Alkasite-Based Restorative Material

Purpose

Nanotechnology offers considerable scope in dentistry to improve dental treatment, care, and prevention of oral diseases through the use of nanosized biomaterials. This study assessed the effect of incorporating alumina nanoparticles (Al₂O₃ NPa) to the recently introduced alkasite-based restorative material (Cention N) on its mechanical properties and surface topographical features.

Materials and Methods

Alumina nanopowder was incorporated into the powder component of Cention N at 5 and 10% (w/w). The unblended powder was used as a control. Compressive strength was assessed using a universal testing machine. Surface microhardness and roughness were evaluated using the Vickers microhardness test and surface profilometer, respectively. Surface topography was inspected using a scanning electron microscope (SEM). Data were analyzed by ANOVA and Tukey's test (P < 0.05).

Results

Incorporation of either 5 or 10% (w/w) Al₂O₃ NPa into alkasite-based restorative materials (Cention N) increased both its compressive strength and surface microhardness. This increase was significant with the use of lower concentration Al₂O₃ NPa (5% w/w). Meanwhile, there was an increase in surface roughness values of Cention N modified with either 5 or 10% (w/w) Al₂O₃ NPa. This increase was only significant in the case of 10% (w/w) Al₂O₃ NPa.

Conclusion

Incorporation of 5% (w/w) Al₂O₃ NPa into the newly introduced alkasite-based restorative material (Cention N) seems to produce a promising restorative material with high compressive strength and surface hardness without adversely affecting its surface roughness properties. Thus, nanotechnology implementation into Cention N restorative material may be strongly helpful for a diversity of clinical applications.

Surface properties and gloss of CAD/CAM composites after toothbrush abrasion testing

The purpose of this study was to evaluate the surface properties and gloss of CAD/CAM composites after toothbrush abrasion testing. Four CAD/CAM composites for molars (Cerasmart 300, Estelite P block, Katana Avencia P block, and KZR-CAD HR3 Gammatheta), one CAD/CAM composite for premolars (Shofu Block HC Hard), and one feldspathic ceramics (Vitablocs Mark II) were assessed. Knoop hardness number, gloss, and surface roughness (Ra, Rz, and Sa) were measured before and after toothbrush abrasion testing. Knoop hardness number values were in the order Vitablocs Mark II > Katana Avencia P block > Estelite P Block > Shofu Block HC Hard > Cerasmart 300 > KZR-CAD HR3 Gammatheta. After testing, the gloss of Estelite P block and KZR-CAD HR3 Gammatheta was greatly decreased and surface roughness was greatly increased. Periodic recall and re-polishing may thus be necessary when these products are used clinically.

Effect of Different Finishing and Polishing Systems on the Surface Roughness of Resin Composite and Enamel: An In vitro Profilometric and Scanning Electron Microscopy Study

Aim

The aim is to compare and evaluate the different finishing and polishing systems for the change in surface roughness of resin composites and enamel.

Materials and Methods

To conduct the study, 30 extracted human maxillary central incisors were selected, decoronated, and molded in self-cure acrylic molds. A box-shaped cavity of dimensions 3 mm × 3 mm × 2 mm was prepared in all the teeth. A nanohybrid composite resin (Filtek Z250) was then used to restore the prepared cavities. Thirty samples were divided into two groups, control group (Group A, n = 10) and experimental group (Group B, n = 20). The samples in Group A were cured through the Mylar matrix. The experimental group, i.e., Group B was divided into two subgroups, i.e., Subgroup BX, n = 10 in which Sof-Lex polishing system was used for polishing the tooth surface and Subgroup BF, n = 10 in which Shofu composite polishing system was used. The mean surface roughness (Ra in μm) of the composite restoration as well as for the enamel surface of all the samples before and after polishing was measured with a contact profilometer, and the values were correlated with scanning electron microscopy.

Results

The statistical analysis was carried out using paired t-test. The results exhibited a significant decrease in the surface roughness of the resin composite and enamel surface irrespective of the finishing and polishing system used. The mean surface roughness values demonstrated by Mylar matrix was the lowest followed by Sof-Lex polishing system. Shofu polishing system demonstrated the highest surface roughness values.

Conclusion

Finishing and polishing of composite restoration can achieve a surface roughness similar to that of enamel. Involvement of marginal enamel in finishing and polishing procedures carried out for composite restoration results in smoother enamel surface.

The effect of red wine on colour stability of three different types of esthetic restorative materials: An in vitro study

Aim and Objective:

To evaluate the in vitro effect of red wine on color stability of three different esthetic restorative materials such as nanohybrid composites, conventional restorative glass ionomer cement (GIC), and feldspathic porcelain.

Materials and Methods:

The color stability of test materials was determined using a spectrophotometer. A total of 30 specimens were prepared (10 from each) from each material on a round metal mold (11 mm diameter and 2 mm deep). The specimens were stored in distilled water at 37°C for 24 h for rehydration. Baseline color of all groups was recorded. Specimens of each material were divided into 2 groups of 5 specimens each (n = 5). Two groups include red wine and distilled water as a control. Specimens were then immersed in 25 ml of red wine for 20 min at room temperature everyday for 28 days. Specimens were kept in distilled water for the remaining part of days. After the completion of immersion sequence, the specimens were rinsed with distilled water and blotted dry. Postimmersion color of all specimens was then recorded. Data were analyzed by two-way ANOVA and post hoc Tukey's test.

Results:

The color stability is significantly higher in porcelain than composite and conventional GIC.

Conclusion:

Within the limitations of this study, it was concluded that the porcelain shows less discoloration than composite and conventional restorative GIC.

Surface roughness of composite resins subjected to hydrochloric acid

The purpose of this study was to determine the influence of hydrochloric acid on surface roughness of composite resins subjected to brushing. Sixty samples measuring 2 mm thick x 6 mm diameter were prepared and used as experimental units. The study presented a 3x2 factorial design, in which the factors were composite resin (n=20), at 3 levels: microhybrid composite (Z100), nanofilled composite (FiltekTM Supreme), nanohybrid composite (Ice), and acid challenge (n=10) at 2 levels: absence and presence. Acid challenge was performed by immersion of specimens in hydrochloric acid (pH 1.2) for 1 min, 4 times per day for 7 days. The specimens not subjected to acid challenge were stored in 15 mL of artificial saliva at 37 oC. Afterwards, all specimens were submitted to abrasive challenge by a brushing cycle performed with a 200 g weight at a speed of 356 rpm, totaling 17.8 cycles. Surface roughness measurements (Ra) were performed and analyzed by ANOVA and Tukey test (p≤0.05). Surface roughness values were higher in the presence (1.07±0.24) as compared with the absence of hydrochloric acid (0.72±0.04). Surface roughness values were higher for microhybrid (1.01±0.27) compared with nanofilled (0.68 ±0.09) and nanohybrid (0.48±0.15) composites when the specimens were not subjects to acid challenge. In the presence of hydrochloric acid, microhybrid (1.26±0.28) and nanofilled (1.18±0,30) composites presents higher surface roughness values compared with nanohybrid (0.77±0.15). The hydrochloric acid affected the surface roughness of composite resin subjected to brushing.

Roughness Analysis on Composite Materials (Microfilled, Nanofilled and Silorane) After Different Finishing and Polishing Procedures

The finishing and polishing of composite materials affect the restoration lifespan. The market shows a variety of finishing and polishing procedures and the choice among them is conditioned by different factors such as the resulting surface roughness. In the present study, 156 samples were realized with three composite materials, -microfilled, nanofilled and silorane-, and treated with different finishing and polishing procedures. Profilometric analyses were carried out on the samples’ surface, the measured roughness values were submitted to statistical analysis. A complete factorial plan was drawn up and two-way analysis of variance (ANOVA) was carried out to investigate whether the following factors affect the values of roughness: (i) material; (ii) polishing/finishing procedure. Tukey post-hoc test was also conducted to evaluate any statistically significant differences between the material/procedure combinations. The results show that the tested materials do not affect the resulting surface quality but roughness values depend on the finishing/polishing procedure adopted. The procedures that involve: (a) the finishing with medium Sof-Lex discs and (b) the finishing with two tungsten carbide multi-blade milling cutters Q series and UF series are those that allow the lowest values of roughness to be obtained.

The effect of three polishing systems on surface roughness of flowable, microhybrid, and packable resin composites

Objectives:

The aim of this study was to evaluate the effects of three different polishing systems on the surface roughness of three types of resin composite materials.

Materials and Methods:

Three types of resin composites (Heliomolar flow, TPH spectrum, and Tetric Ceram HB) and three polishing systems (Astropol, Enhance, and Soflex) were used. A total number of 40 samples were prepared from each one of the restorative materials and divided randomly into four groups (n = 10) according to the polishing procedure. The first group underwent no treatment and was used as a control group. Each one of the remaining groups was polished with one of the tested polishing systems. After completion of sample preparation, the mean surface roughness (Ra) value was measured using a surface profilometer. Data were analyzed using one-way analysis of variance (ANOVA).

Results:

The control group of each material recorded the lowest Ra value. Among the tested polishing systems, the groups finished with Soflex system exhibited the lowest Ra value. Among the resin composites, Heliomolar flow exhibited the lowest Ra value, regardless of the polishing system used.

Conclusions:

The smoothest surface of all types of resin composite was achieved under Mylar strip.

The assessment of surface roughness and microleakage of eroded tooth-colored dental restorative materials

Objectives:

To investigate the effect of acidic solution on surface roughness and microleakage of tooth-colored restorative materials.

Materials and Methods:

A 160 box-shaped cavities were prepared on the buccal surfaces of 160 human molars, and assigned to four groups: Group A restored with Ketac™ Molar Easymix, Group B with Fuji II™ LC, Group C with Ketac™ N100, and Group D with Filtek™ Z250, and subdivided into study and control groups (n = 20). Study groups were immersed in lemon juice (pH = 2.79) for 24 h, whilst controlgroups in deionized distilled water. All samples were immersed in 2% methylene blue dye, sectioned into two equal halves for surface roughness, and microleakage tests. Data were analyzed using Mann–Whitney and Kruskal–Wallis tests at P < 0.05.

Results:

There was a significant difference in surface roughness of Ketac™ Molar, Fuji II™ LC, and Ketac™ N100. No significant difference was found in microleakage of Ketac™ Molar and Fuji II™ LC; however, there were significant differences in the gingival margin of Ketac™ N100, and the occlusal margin of Filtek™ Z250.

Conclusions:

All glass ionomer cements were eroded after exposure to the acidic drink. Filtek™ Z250 and Ketac™ Molar Easymix showed more microleakage. All materials showed more microleakage at the gingival margins.

Evaluation of effect of ultrasonic scaling on surface roughness of four different tooth-colored class V restorations: An in-vitro study

AIMS

This study evaluated the effect of ultrasonic scaling on surface roughness of four different tooth-colored class V restorations.

MATERIALS AND METHODS

Out of 100 human extracted teeth, 20 were randomly selected for each group, marked with the outline of class V cavity. Class V cavities were prepared on facial surface of teeth of all groups except control group. These cavities were then restored with GC 2, GC 9, GC 2 LC, and Filtek Z 250 XT. All the specimens were stored in artificial saliva at 37°C for 1 month. Initial surface roughness values (Ra in μm) of restorations were evaluated with the surface roughness tester. Ultrasonic instrumentation was then carried out for 60 s on the restoration surface and final roughness values were evaluated. Data were analyzed with Paired t-test, One-way ANOVA, Tukey's test.

RESULTS

Mean Pre-instrumentation surface roughness was highest with GC 2, whereas it was least in case of Filtek Z 250 XT. Mean post-instrumentation surface roughness was highest with GC 2, whereas it is least in case of Filtek Z 250 XT.

CONCLUSION

GC 2 LC showed highest and Filtek Z 250 XT showed least susceptibility to ultrasonic scaling.

Effects of sports beverages and polishing systems on color stability of different resin composites

BACKGROUND

Consumption of certain acidic beverages may alter the physical and esthetic properties of resin composites.

AIM

The aim of this study was to evaluate the effects of two sports beverages on color stability of two different types of resin composites polished with different composite polishing systems.

MATERIALS AND METHODS

A total of 96 disk-shaped specimens (diameter: 8-mm and thickness: 2-mm) were made from two different resin composites (Cavex Quadrant Universal-LC, and Clearfil-APX). All of the specimens were stored in distilled water for 24 h at 37°C. Color measurements of each specimen were performed using a colorimeter according to the CIEL*a*b* color scale at baseline and after seven days of immersion in two different sports beverages (Powerade and Buzzer).

STATISTICAL ANALYSIS USED

The data were evaluated using Kruskal Wallis and Mann-Whitney U tests.

RESULTS

Significant differences were found between the mean ΔE values of the groups after seven days of immersion (P < 0.05). The highest level of the mean color change was observed in the Clearfil APX specimens immersed in Powerade (ΔE = 3.5 ± 0.9). Control groups stored in distilled water for both composites exhibited small color changes (ΔE-Cavex-bur = 2.1 ± 1; ΔE-Clearfil APX-bur = 2.1 ± 0.4).

CONCLUSION

Sport beverages caused discoloration in the resin composites after seven days.

In vitro evaluation of the effect of two finishing and polishing systems on four esthetic restorative materials

Aim:

To determine the surface roughness of esthetic restorative materials after finishing and polishing.

Materials and Methods:

All 60 specimens were divided into four groups. Group I: Nanocomposite, Z 350 XT (3M ESPE, USA); Group II: Microhybrid composite, Z 250 (3M ESPE, USA); Group III: Compomer, Dyract XP (LD Caulk/Dentsply, USA); and Group IV: Resin modified glass ionomer cement (GIC), Fuji II LC (GC, Japan). Each group was again divided into three subgroups. Subgroup A: Sof-Lex (3M ESPE); Subgroup B: Super-Snap Rainbow finishing and polishing kit (Shofu INC, Japan); and Subgroup C: Control Mylar strip. Surface roughness was determined by Perthen Perthometer S6P profilometer.

Result:

Filtek Z350 XT showed minimum surface roughness followed by Filtek Z250, Dyract XT and Fuji II LC. Super-Snap exhibited less surface roughness than Sof-Lex polishing systems.

Statistical Analysis:

One-way analysis of variance (ANOVA) followed by multiple post hoc comparisons using least square difference method and unpaired t-test was used.

Conclusion:

Filtek Z350 XT with Mylar strip exhibited least surface roughness.

Surface geometry of various nanofiller composites using different polishing systems: A comparative study

AIM

This in vitro study assessed the surface quality of three nanoparticle composites with four commercially available polishing systems.

MATERIALS AND METHODS

A total of 180 specimens (10 × 2 mm) were prepared in metal molds using three nanocomposites, Filtek Z-350 XT, Ceram-X Mono, and Tetric N-Ceram. Sixty specimens of each material were then randomly assigned to five study groups. Control specimens were left untreated and the remaining specimens were subjected to polishing with SpinBrite, CompoMaster, AstroPol, and SofLex polishing systems. Average roughness (Ra) and average ten-point roughness (Rz) were calculated using Perthometer, and the data were analyzed by two-way analysis of variance (ANOVA) and post-hoc Tukey's tests.

RESULTS

For all the materials, the roughest surfaces were observed for control specimens, with no statistically significant differences between the material groups. For Filtek Z-350 XT, the decrease in surface roughness after two-step polishing was insignificant. For Ceram-X, SpinBrite specimens showed similar degree of roughness as control specimens. For Tetric N-Ceram, no significant decrease in roughness was observed after one-step polishing. Two-way ANOVA (interaction of subgroups and groups) did not show a significant association with the outcome.

CONCLUSIONS

For nanofilled composites (Filtek Z-350 XT), the surface roughness decreased with the increase in number of polishing steps, whereas one-step and multi-step polishing procedures produced similar quality of smoothness for nanohybrid composites (Ceram-X, Tetric N-Ceram). Ra and Rz values of surface roughness are a function of type of finishing/polishing only.