Effect of Toothpaste on the Surface Roughness of the Resin-Contained CAD/CAM Dental Materials: A Systematic Review

Effect of Experimental Bleaching Gels With Enzymes on Composite and Enamel

INTRODUCTION AND AIMS

Potential secondary or toxic effects of peroxide-based whitening gels have driven the search for alternative methods that use natural compounds with gentle action on tooth enamel that provide remineralizing benefits.

METHODS

This study introduces four innovative experimental whitening gels (GC, G1, G3, G4) formulated with enzymes (Bromelaine and Papaine) and natural extracts, along with SiO2. The efficacy of these gels was tested on nanohybrid dental composite (EsCOM100, Spident Company) and dental enamel stained with coffee and natural juice (Tedi) over 10 days. The structural changes in samples before and after bleaching were examined using scanning electron microscopy and atomic force microscopy. Additionally, cytotoxicity tests were conducted on the gels using mesenchymal stem cells from human dental pulp (dMSC) and human keratinocytes (HaCaT). Antibacterial activity was assessed on five strains (Streptococcus mutans. Porphyromonas gingivalis; Enterococcus faecalis; Escherichia coli; Staphylococcus aureus).

RESULTS

Coffee and natural juice stains significantly increase the roughness of composite and enamel surfaces by forming deposits. The enzymatic action of bromelain and papain effectively disorganizes and removes these clusters, significantly reducing surface roughness.

CONCLUSION

Notably, the gel containing papain and nanostructured SiO2 proved to be the most effective in removing coffee stains from both composite surfaces and enamel. On the other hand, the gel with bromelain and nanostructured SiO2 was the most efficient in removing natural juice stains. The absence of SiO2 in the experimental gels slightly decreased the enzymes' effectiveness in stain removal. The antibacterial activity observed in the experimental gels is attributed solely to the enzymatic compounds.

Effects of two dentifrices on the surface properties and staining susceptibility of polymer-based materials

PURPOSE

This study examined the effect of whitening and abrasive regular dentifrices on the surface characteristics and stain susceptibility of polymer-based CAD-CAM blocks subjected to artificial toothbrushing abrasion (TB).

MATERIALS AND METHODS

Two resin composite blocks [CeraSmart (CS) and Grandio Blocs (GB)], one polymer-infiltrated ceramic [Vita Enamic (VE)], and one direct resin composite [GrandioSO (RC)] were used to produce 60 specimens. The baseline mass, gloss, roughness, Vickers hardness (Hv), and color were measured after 7 days of water storage. The specimens were then separated into three TB treatment groups (n = 5): water control (C), regular daily dentifrice (R), and whitening dentifrice (W). Measurements were repeated post-TB (20,000 cycles). All specimens were immersed in coffee, and the CIE ΔE00 was measured after 1, 7, and 14 days. Two-way, one-way ANOVA, and Tukey's post hoc tests were performed to determine any significant differences between the materials and TB groups. To determine the stain resistance, repeated measures of ANOVA, one-way ANOVA, and Tukey's post hoc tests were used (α = 0.05).

RESULTS

The R and W mass changes were minimal (-3.77 to 3.16 g%). W reduced the gloss of all the materials by 12.6%-65%. All materials in W were slightly rougher (Ra, 0.107-0.144 μm) than those in R (Ra, 0.049-0.072 μm). The ΔE00 ranged from 0.6 to 1.6 in W and 0.4 to 1.4 in R. VE was the hardest material at baseline (Hv = 362), whereas brushing and staining lowered Hv in all TB groups (282.8-300.6). After brushing in W, VE, and RC were more susceptible to coffee stains than were CS and GB.

CONCLUSIONS

The whitening dentifrice roughened CAD-CAM specimens, reducing gloss, yet lightened some materials. Polymer-infiltrated ceramic and direct resin composite specimens brushed with abrasive regular or whitening dentifrice resulted in more intense staining than the CAD-CAM resin composites.

The effect of in-office bleaching agents on the Vickers hardness and surface topography of polished and unpolished CAD/CAM composite materials

In-office bleaching, using hydrogen peroxide, is effective to remove dental enamel stains. However, bleaching agents can deteriorate surface properties of CAD-CAM materials. This in vitro study aimed to investigate the effect of in-office bleaching agents on Vickers hardness and surface topography of polished and unpolished dental CAD-CAM composite materials (Grandio blocs, Lava Ultimate, BRILLIANT Crios, Cerasmart), and a polymer-infiltrated ceramic network block (Vita Enamic). The specimens were randomly divided into two groups: unpolished or polished. The micro-hardness and surface topography of each group were measured before bleaching, after a 60 min bleaching period, and 24-h and one-month post-bleaching. In-office bleaching significantly influenced the Vickers hardness of both the polished and unpolished CAD/CAM composite blocks, with Vita Enamic exhibiting the least hardness stability among all groups. Furthermore, in-office bleaching significantly influenced the surface roughness of unpolished CAD/CAM composite blocks. There was a significant difference in hardness reduction between the polished and unpolished specimens for most of the investigated materials at different time points. The bleaching did not influence the surface roughness of the investigated polished group, except for Vita Enamic and Lava Ultimate. However, it did influence the surface roughness of the investigated materials in the unpolished group.

Influences of Different CAD/CAM Ceramic Compositions and Thicknesses on the Mechanical Properties of Ceramic Restorations: An In Vitro Study

The aim of this study was to assess the influences of different CAD/CAM ceramic compositions and thicknesses on the surface roughness and hardness of ceramic restorations. Four different ceramics were used in the current study: lithium disilicate (LD), leucite reinforced (LE), advanced lithium disilicate (ALD), and zirconia-reinforced lithium silicate (ZLS). Each group included 30 specimens subdivided into three different ceramic thicknesses (0.5, 1 and 1.5 mm thicknesses). The microhardness was measured for all the specimens using a microhardness testing machine, while the surface roughness was measured using a non-contact optical profilometer at three intervals (before toothbrushing and after toothbrushing, with and without toothpaste). Three-way and two-way ANOVA were used to determine the factors influencing the surface roughness and microhardness. There was a significant difference in the surface roughness between the studied groups for all the thicknesses. The findings showed that ALD had the lowest surface roughness, while ZLS showed the highest surface roughness. Moreover, ALD, followed by ZLS, had the highest hardness, while LD and LE had the lowest hardness values. Regarding the thicknesses, both the 0.5 and 1 mm ceramic thicknesses showed a significantly lower surface roughness than the 1.5 mm thickness, while the 1.5 mm thickness showed a significantly higher microhardness than the 0.5 mm thickness. The surface roughness and hardness were significantly affected by the ceramic composition and type of filler. It is recommended to use 1.5 mm-thick ceramic materials for the fabrication of definitive full-coverage ceramic restorations, while veneers require 0.5 mm-thick materials. ALD is a promising CAD/CAM material that can be used for the fabrication of restorations with a proper strength in both anterior and posterior regions.