Bonding strategies for MIH-affected enamel and dentin

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Clinical Dentistry

Background:

• Molar incisor hypomineralisation (MIH) affects dental hard tissues, potentially compromising resin composite adhesion.
• Understanding the adhesion challenges in MIH is crucial for effective restorative treatments.

Purpose of the Study:

• To evaluate the resin composite adhesion to dental hard tissues, specifically enamel and dentin, affected by molar incisor hypomineralisation (MIH).

Main Methods:

• Micro-tensile bond strength (μ-TBS) tests and qualitative evaluations (SEM, histology) were performed on human molars and incisors with and without MIH.
• Three dental adhesives (Clearfil SE Bond, Scotchbond Universal, OptiBond FL) were tested. Additional treatments (NaOCl, Icon) were investigated for MIH-affected enamel.

Main Results:

• Dentin specimens exhibited significantly higher μ-TBS values, independent of the adhesive used.
• MIH-affected enamel showed significantly lower μ-TBS values compared to sound enamel, with certain adhesives performing poorly.
• Pre-treatments with NaOCl or Icon did not improve enamel bonding but reduced pre-test failures. Micromorphological analysis revealed porous enamel in MIH as a weak link.

Conclusions:

• Resin composite adhesion to porous, hypomineralized MIH enamel is the primary limiting factor in restorative success for MIH teeth.
• Conventional bonding protocols appear suitable for MIH-affected dentin.