Initial dissolution rate studies on dental enamel after CO2 laser irradiation

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Laser-Tissue Interactions

Background:

• Dental enamel's susceptibility to acid dissolution is a primary factor in caries development.
• Understanding enamel's surface chemistry is crucial for developing effective caries prevention strategies.

Purpose of the Study:

• To investigate the effect of CO2 laser irradiation on the dissolution behavior of human dental enamel.
• To determine if laser treatment alters enamel's surface properties and solubility.
• To assess the synergistic effects of laser treatment with common dissolution inhibitors.

Main Methods:

• Human enamel samples were irradiated with a continuous-wave CO2 laser.
• Initial dissolution rates (IDRs) were measured using a rotating disk assembly in acetate buffer.
• The influence of calcium, phosphate, (1-hydroxyethylidene) bisphosphonic acid (EHDP), fluoride (F), and dodecylamine HCl (DAC) on IDR was evaluated.

Main Results:

• CO2 laser irradiation significantly decreased the dissolution driving force of enamel, converting it to a hydroxyapatite (HAP) form with site #2 character.
• IDRs were substantially reduced in the presence of EHDP and DAC after laser treatment, consistent with site #2 HAP.
• The dissolution driving force for fluoride was also markedly reduced post-laser irradiation, indicating enhanced inhibition.

Conclusions:

• CO2 laser irradiation effectively modifies human dental enamel, creating a surface with significantly lower solubility.
• Laser treatment demonstrates synergistic effects with dissolution inhibitors like EHDP, fluoride, and DAC.
• These findings suggest laser irradiation could be a valuable adjunct in reducing enamel susceptibility to acid challenges in the oral environment.