Work

Effect of Bleaching on the Surface Roughness of Resin Composites Evaluated by Atomic Force Microscopy (AFM)

Year: 2025

Type: article

Abstract: Background/Objectives: Composite resins are widely used restorative materials, but their surface properties may be altered by bleaching procedures. This study aimed to compare the effects of two bleaching techniques—light-activated (zoom) and diode laser-activated—on the surface roughness of nanohybrid and microhybrid composites using Atomic Force Microscopy (AFM) for topographic evaluation. Methods: A total of 60 composite resin disks were fabricated, with 30 nanohybrid and 30 microhybrid samples. Each type was divided into three subgroups: control, zoom bleaching, and laser bleaching (n = 10 per group). Zoom bleaching employed 40% hydrogen peroxide gel activated by the Philips Zoom system, while laser bleaching used a 940 nm diode laser (QuickLase, Kent, UK) in combination with QuickLase bleaching gel containing approximately 35–40% hydrogen peroxide. Surface roughness parameters (Sa) were measured using AFM, and statistical analysis was performed. Results: Both bleaching protocols increased surface roughness compared to controls. Microhybrid composites showed higher roughness after zoom (103.12 ± 19.25 nm) and laser bleaching (106.16 ± 25.21 nm), while nanohybrid composites had lower values after zoom (57.77 ± 13.88 nm) and laser bleaching (78.13 ± 23.29 nm). Significant differences were found between composite types post-bleaching (p < 0.001 for zoom; p = 0.019 for laser). However, differences between bleaching methods within the same composite type were not significant (p > 0.05). Conclusions: Both zoom and laser bleaching negatively affect composite surfaces, with laser bleaching showing a greater impact. Nanohybrid composites demonstrated superior resistance to surface alteration, suggesting better clinical durability. These findings are relevant for clinicians when planning restorative treatments in patients likely to undergo bleaching.

Source: Dentistry Journal

DOI: 10.3390/dj13100470

Authors: Kabas Abdullla Fadhil, Bassam Karem Amin

Institution: Hawler Medical University

Language: English

Topic: Dental materials and restorations

Subfield: Orthodontics

Field: Dentistry

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $2,413