Evaluation of the Effect of Whitening Toothpastes on the Surface Roughness of Bioactive Restorative Materials Using Atomic Force Microscopy and Optical Profilometer and SEM-EDS Analysis.

Abstract

Objective: This study aimed to evaluate the effects of whitening toothpastes on the surface roughness and elemental composition of bioactive restorative materials.

Materials and methods: A total of 210 disk-shaped specimens were prepared from Equia Forte HT (EF), Activa Bioactive Restorative (AB), Cention Forte (CF), Beautifil II (BF), and Filtek Z250 (FZ, control). The specimens underwent simulated toothbrushing using charcoal-containing, hydrogen peroxide (H₂O₂)-containing, and fluoride-containing toothpastes, as well as distilled water (control). Surface roughness was measured before and after 30,000 brushing cycles using atomic force microscopy (AFM) and optical profilometry. Changes in elemental composition were assessed by SEM-EDS.

Results: EF exhibited the greatest increase in surface roughness, followed by AB and CF, while BF and FZ showed the least changes. Charcoal- and H₂O₂-containing toothpastes caused significant surface degradation and chemical alterations in filler particles, whereas fluoride-containing toothpaste better preserved surface integrity. SEM-EDS analysis confirmed the role of fluoride in enhancing chemical stability.

Conclusions: Bioactive materials showed varying degrees of sensitivity to abrasives. EF and AB experienced considerable wear, particularly with charcoal- and H₂O₂-based toothpastes, potentially compromising clinical durability. Fluoride-containing toothpaste provided better chemical and surface stability.

Clinical significance: Charcoal- and H₂O₂-containing toothpastes may accelerate the degradation of bioactive restorations, reducing their longevity. Fluoride-containing toothpaste appears to better maintain surface integrity and may be preferable for patients with aesthetic restorations.