Influence of Toothbrush Abrasion and Surface Treatments on Roughness and Gloss of Polymer-Infiltrated Ceramics.

Nawaf Labban,Sarah M Alnafaiy,Mounir Iskandar,Sabrina Feitosa,Mohammad A Alenizy,Saleh M Alhijji,Mohammad D Al Amri

doi:10.3390/polym13213694

Abstract

The aim of this study was to compare the surface roughness and gloss of polymer-infiltrated ceramics after simulated in vitro toothbrushing in different storage mediums. Four polymer- infiltrated ceramics were evaluated, Lava ultimate (LU), Vita enamic (EN), Shofu (SH), and Crystal ultra (CU). The control group was a feldspathic ceramic, Vita Mark II (VM). One hundred and twenty specimens (12 × 14 × 2.5 mm) were prepared using a precision saw. For each material (n = 24), the specimens were allocated into two groups, polished and stained. The specimens of each group were stored (for 7 days) in either citric acid (0.2N) or distilled water. Data for surface gloss (ΔE*SCE-SCI) and roughness (Ra) were evaluated before (baseline) and after simulated toothbrushing. For toothbrushing simulation, a toothpaste slurry containing a toothpaste of 100 relative dentin abrasion (RDA) and 0.3 ml distilled water was used for 3650 cycles (7300 strokes) for each specimen. Data were analyzed using t-test and ANOVA. A p-value of ≤ to 0.05 was considered significant. The highest mean value of surface gloss was identified in CU (stained—water) (4.3 (0.47)) (ΔE*) and EN (stained—acid) (4.3 (1.00)) (ΔE*) specimens, whereas the lowest mean value was shown by SH (stained—acid) (2.04 (0.42)) (ΔE*) samples. The highest mean value of surface roughness was observed in SH (0.40 (0.99)) Ra (stained—acid) whereas the lowest in VM (0.13 (0.039)) Ra (polished— water). A significant difference (p < 0.05) was observed in surface roughness and gloss between the materials with simulated toothbrushing, except in VM and LU, respectively. Therefore, it can be concluded that simulated toothbrushing impacts on surface roughness and gloss, irrespective of the storage medium.

Highlights

Aesthetic maintenance of dental restorations is a challenge faced in dental practice.Continuous efforts have been made to improve restorative surface qualities such as gloss and surface roughness
The highest mean value of surface gloss (∆E*Specular Component Excluded (SCE)-Specular Component Included (SCI)) was identified for groups Crystal ultra (CU) (4.3 (0.47)) ∆E and EN (4.3 (1.00)) ∆E, whereas the lowest mean value was shown by group SH (2.04 (0.42)) ∆E
The present study evaluated the effect of toothbrush abrasion and acidic storage on surface gloss and roughness in polymer-infiltrated ceramics (Lava Ultimatum, Vita Enamic, Shofu, and Crystal Ultra) in comparison to a feldspathic ceramic (Vita M block II)

Summary

Introduction

Aesthetic maintenance of dental restorations is a challenge faced in dental practice.Continuous efforts have been made to improve restorative surface qualities such as gloss and surface roughness. They classified highly cured resin matrix reinforced with approximately 80% nano-ceramic particles as resin nanoceramics Another type of polymer-infiltrated ceramic is “Glass ceramic in resin interpenetrating matrix”, which is comprised of a dual network of feldspathic ceramic and a polymer network [1]. Resin-infiltrated ceramics are composed of two interlocking structures: low-viscosity polymer infiltrated into a sintered glass–ceramic network [3]. This fusion of polymers with ceramics contributes to substantial mechanical strength with a lustrous, glossy, and smooth surface [3]. Wear resistance, chemical stability, and aesthetic appeal promote the adoption of polymer-infiltrated ceramics in clinical practice

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