[Composite retention area produced by CO2 laser beam].

Area of Science:

• Dental materials science
• Biomedical engineering
• Laser-tissue interactions

Background:

• Dental composite resins require effective surface preparation for optimal adhesion.
• Lasers offer a potential alternative to traditional methods like acid etching for enamel surface modification.
• Understanding laser-enamel interactions is crucial for developing new dental procedures.

Purpose of the Study:

• To evaluate the effectiveness of CO2 laser treatment on enamel retention for composite resin anchoring.
• To compare the bond strength of composite resin to laser-treated enamel versus acid-etched enamel.

Main Methods:

• Intact premolar approximal enamel surfaces were treated with a CO2 laser at varying parameters (0.5, 1, 3 W; 1, 1.5 mm spot size; 0.2, 0.5 s).
• Composite resin was applied to the laser-treated and acid-etched enamel surfaces.
• The bond strength of the composite-enamel interface was measured and compared.

Main Results:

• Composite-enamel interfaces bonded to lased enamel demonstrated significantly higher bond strengths than those bonded to untreated enamel (p < 0.01).
• The bond strength of composite to laser-treated enamel was significantly lower than that achieved with traditional acid etching (p < 0.01).
• Laser treatment parameters influenced the resulting enamel surface morphology, including melting, vaporization, crater, and fissure formation.

Conclusions:

• CO2 laser treatment can create a retentive surface on enamel for composite resin anchoring, improving adhesion compared to untreated enamel.
• While laser treatment shows promise, acid etching currently provides superior bond strength for dental composite applications.
• Further research into optimizing laser parameters may enhance its efficacy for dental adhesion procedures.