# The Influence of Erosive and Abrasive Effects of Interdental Brushing on Bovine Enamel and Dentine In Vitro

## TL;DR

This study examines how interdental brushing and acid erosion affect bovine enamel and dentine, finding that combined effects cause the most damage.

## Contribution

The study introduces a novel combined protocol of erosion and abrasion to assess their cumulative impact on dental tissues.

## Key findings

- Combined erosion and abrasion caused the highest enamel substance loss after 10 days.
- Erosion alone led to significant dentin substance loss compared to abrasion and combined protocols.
- Enamel damage occurred in all groups except abrasion-only, highlighting the need for preventive measures.

## Abstract

To investigate the effects on enamel and dentine caused by erosion with hydrochloric acid (HCl) or abrasion with interdental brushes and toothpaste, and a combined protocol using roughness and profilometry measurements as well as scanning electron microscopy images.

24 bovine enamel samples and 24 dentine samples were divided into three groups each (groups 1–3: enamel; groups 4–6: dentin; n = 8) and investigated after an abrasion protocol (2 × 10 brushing cycles per day) in groups 1 and 4, a combined protocol (10 brushing cycles, 10 × 2min erosion in HCl, 10 brushing cycles per day) in groups 2 and 5 and an erosion protocol (10 × 2min erosion in HCl) in groups 3 and 6 for 10 days. Profilometry and roughness measurements were registered at baseline, after 5 and after 10 days. Scanning electron microscopy (SEM) images were recorded at baseline and after 10 days.

For enamel, the significantly highest substance loss (mean ± SD) after 5 days was observed in the combined group (10.71 ± 0.41 μm), whereas the second highest substance loss was in the erosion-only group (9.16 ± 0.23 μm). In dentin, the highest substance loss after 5 days occurred in the combined group (7.4 ± 0.83 μm), and the second highest substance loss was presented in the erosion-only group (7.26 ± 0.5 μm). After 10 days, the combined group (18.88 ± 0.56 μm) exhibited the highest substance loss in enamel, showing a statistically significant difference compared with the erosion-only and abrasion-only groups (P <0.001, respectively). In dentin, the highest substance loss was observed after 10 days in the erosion-only group (7.96 ± 0.8 μm), exhibiting a statistically significant difference compared to both the combined (P = 0.022) and abrasion-only groups (P <0.001).

In all groups, with the exception of abrasion-only groups, enamel substance loss occurred. Thus, measures against erosive and abrasive wear, both alone and combined, have to be implemented, such as comprehensive patient education.