Comparison of the Microhardness of Surface Enamel Exposed to Anti-asthmatic Inhalants

To determine the effect of anti-asthmatic inhalers salbutamol and budesonide on the surface microhardness of bovine tooth enamel.

The study was experimental, prospective, longitudinal, and comparative. The sample consisted of permanent mandibular incisors, which were prepared in (n = 90) blocks of dental enamel of size 3 × 3 mm and 2 mm thick, separated into 6 groups of 15 specimens each in sterile bottles properly labeled and contained in artificial saliva at 37°C. Three measurements (baseline, 5 days, and 10 days) were performed after immersion to determine the microhardness using a Vickers microdurometer programmed to apply a load of 100 gm for 15 seconds.

It was observed that the enamel surface microhardness decreased after 5 and 10 days, after being in contact with the anti-asthmatic inhalers based on salbutamol and budesonide. In addition, it was evidenced that there is a greater decrease in the superficial microhardness of the enamel when comparing the values at the beginning and after 10 days; likewise, the reduction in the microhardness of enamel exposed to budesonide was greater (120.8 kg/mm²) compared to salbutamol (112.3 kg/mm²) (p<0.001).

The two anti-asthmatic inhalers studied decreased superficial enamel microhardness, with the budesonide-based inhaler having a greater erosive effect.

This research allowed us to know the values of the microhardness of the superficial enamel after being exposed to different anti-asthmatic inhalers that are indicated in daily clinical practice. Therefore, it is important to evaluate this microhardness since the use of different inhalers is very prevalent.