Enhanced permeability of acid-etched or ground dental enamel.
BACKGROUND
Acid etching creates retentive microcraters on enamel surfaces. Designing of a partial denture often involves reshaping the supporting and retentive teeth by grinding the enamel. Unfortunately, both these procedures damage the enamel surface. In vivo such surface damage takes several months to recover.


OBJECTIVE
This study evaluated the effect of 1-minute etching, prolonged etching, and grinding on the permeability of dental enamel for water-soluble molecules.


METHODS
With the electron paramagnetic resonance and a two-chamber diffusion cell, the influence of etching and grinding on the diffusion of spin label molecules through the enamel was studied quantitatively. The enamel permeability was measured in 30 sound enamel samples, of which 10 samples were exposed to 1-minute etching with 37% phosphoric acid, 10 samples were etched for 5 minutes, and 10 samples were ground with a diamond bur.


CONCLUSIONS
All procedures significantly increased the permeability of dental enamel. These results demonstrate that in vivo the acid-etched and ground dental enamel surfaces are less protected and consequently, unless the tooth is properly protected, are more susceptible to carious lesions. Therefore ground or accidentally etched enamel should be protected.
Kuhar
M
M
Department of Dentistry, Medical Faculty, University of Ljubljana, Slovenia.
Cevc
P
P
Schara
M
M
Funduk
N
N
D000134:Acid Etching, Dental; D000328:Adult; D003497:Cyclic N-Oxides; D003733:Dental Caries Susceptibility; D003743:Dental Enamel / Q000378:metabolism; D003745:Dental Enamel Permeability; D003779:Denture Design; D003829:Denture, Partial; D018130:Diamond; D004058:Diffusion; D015194:Diffusion Chambers, Culture; D004578:Electron Spin Resonance Spectroscopy; D006801:Humans; D008875:Middle Aged; D010756:Phosphoric Acids / Q000008:administration & dosage; D012995:Solubility; D013113:Spin Labels; D013997:Time Factors; D019231:Tooth Preparation, Prosthodontic / Q000295:instrumentation / Q000379:methods; D014867:Water / Q000378:metabolism
D003497:Cyclic N-Oxides; D010756:Phosphoric Acids; D013113:Spin Labels; D014867:Water; D018130:Diamond; C003959:TEMPO