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Enamel structural changes induced by hydrochloric and phosphoric acid treatment
Angelica Bertacci1, Alessandra Lucchese, Paola Taddei
11 School of Dentistry, Department of Biomedical and Neuromotor Sciences (DiBiNeM), University of Bologna, Bologna - Italy.
Journal of Applied Biomaterials & Functional Materials
|April 5, 2014
Summary
Dental etching with hydrochloric acid (HCl) or phosphoric acid (H3PO4) alters enamel structure and permeability. Phosphoric acid reduces permeability by decreasing organic matter, while hydrochloric acid maintains it.
Area of Science:
- Dental materials science
- Biomaterials research
- Surface chemistry
Background:
- Enamel demineralization is a critical factor in dental caries.
- Acid etching is a common dental procedure to modify enamel surface properties.
- Understanding acid-induced structural changes is vital for restorative dentistry.
Purpose of the Study:
- To analyze enamel structural changes induced by hydrochloric acid (HCl) and phosphoric acid (H3PO4) etching.
- To correlate these structural changes with enamel permeability.
- To investigate the impact of etching on fluid discharge from the enamel surface.
Main Methods:
- Enamel slices were etched with 15% HCl or 37% H3PO4.
- Raman and infrared (IR) spectroscopy were used to analyze structural changes.
- Enamel permeability was assessed by measuring fluid discharge from replicas.
Main Results:
- Both HCl and H3PO4 decreased enamel carbonate content and formed HPO42- ions.
- H3PO4 etching reduced the organic component of enamel, decreasing permeability.
- HCl etching increased the organic component, maintaining enamel permeability.
Conclusions:
- Enamel permeability is influenced by the etching technique and the resulting organic matter content.
- Changes in enamel structure and permeability after acid etching have implications for restoration success.
- Findings suggest a link between organic matter, permeability, and potential restoration failures like marginal seal issues.
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