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

Effect of different polishing systems and speeds on the surface roughness of resin composites

Aims and Objectives

The objective of this study was to compare surface roughness of a nano-spherical resin composite using four different multi-step polishing disc systems at five different speeds.

Materials and Methods

In total, 154 discs samples were prepared using a supra-nano spherical resin composite. The samples were divided into negative and positive control groups and the following four finishing and polishing disc systems: Sof-Lex, Bisco Finishing Discs, OptiDisc, and Super-Snap. Each polishing disc system was applied at five different speeds (2000, 5000, 10,000, 15,000, and 20,000 revolutions per minute [RPM]) (n = 7). The surface roughness of samples was measured using a profilometer. One sample from each group was evaluated by scanning electron microscopy and atomic force microscopy. Two-way analysis of variance was used to evaluate the average roughness (Ra) data from the profilometric experiments using statistical software (GraphPad Prism4-GraphPad Software; La Jolla, CA, USA). The mean values were compared using the Bonferroni test (P = 0.05).

Results

The mean roughness ranged from 0.07 μm to 0.41 μm. The smoothest surfaces were obtained with OptiDisc at 20,000 RPM and Super-Snap at 20,000 RPM. The Bisco Finishing Discs group at 2,000 RPM showed the highest surface roughness values. For all polishing systems, the roughness at 20,000 RPM was lower than that at other speeds.

Conclusion

Within the limitations of the present in vitro study, it can be concluded that the polishing performance was in the following order: Super-Snap > OptiDisc > Sof-Lex > Bisco Finishing Discs. In addition, the surface roughness decreased as the polishing speed increased.

Evaluation of Glass-Ionomer versus Bulk-Fill Resin Composite: A Two-Year Randomized Clinical Study

Background: The aim of this split-mouth design research was to compare the clinical performance of a glass-ionomer cement system on Class I/II cavities against the clinical performance of bulk-fill resin composite restoration materials. Methods: Thirty-five patients were randomized and enrolled in the study, aged between 10 and 12 years, all of whom had a matched pair of permanent mandibular carious molars with similar Class I/II. A total of 70 restoration placements were performed. The patients were each given two restorations consisting of either a glass-ionomer cement with a nano-filled coating or a bulk-fill resin composite after the use of a self-etch adhesive. The cumulative survival rates were estimated using log-rank test and the Kaplan−Meier method. For comparison of the restorative materials in line with the modified Ryge, the McNemar test and the Wilcoxon signed rank test were employed. Results: With regard to retention, the glass-ionomer cement system and bulk-fill resin composite performed similarly in permanent molars in Class I/II cavities over a period of up to 24-months (p > 0.05). Over the 24-month period, Class I restorations showed statistically better survival rates than Class II restorations (p < 0.05). In the case of glass-ionomer cement systems, over the two-year period, more common chipping and surface degradations were observed. Conclusions: The glass-ionomer cement system and bulk-fill resin composite restorative materials display good clinical performance over a period of 24-months.

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.

Impact of Polishing Systems on the Surface Roughness and Microhardness of Nanocomposites

AIM

The aim of this article is to evaluate the influence of finishing and polishing techniques on the surface roughness and microhardness of two composite resins with two different types of polishing systems.

MATERIALS AND METHODS

A total of 30 disk-shaped specimens of nanocomposite Filtek™ Z350 and Ceram-X® were prepared. They were divided into three groups. The control group (n = 10) received no finishing and polishing. The remaining specimens were divided into two groups, and they received polishing and finishing either with PoGo or Sof-Lex system. After the polishing procedures, average surface roughness (Ra) was assessed with a surface profilometer. The microhardness was determined using a Vickers hardness test. The data were tabulated and analyzed.

RESULTS

The smoothest surfaces were noticed with the control group (Mylar strips) in both composite materials tested. The PoGo one-step polishing system showed significantly better surface roughness compared with the Sof-Lex polishing system. The microhardness did not show any significant variations after finishing and polishing.

CONCLUSION

It can be concluded that the use of PoGo® one-step polishing system resulted in smoother surface with both composite materials studied compared with the Sof-Lex system. The finishing and polishing system had little influence on the surface microhardness.

CLINICAL SIGNIFICANCE

The finishing procedure and polishing system can affect the physical properties and performance of resin composites.

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.

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.