Microtensile bond strength to enamel affected by hypoplastic amelogenesis imperfecta

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Enamel Microstructure Analysis

Background:

• Hypoplastic amelogenesis imperfecta (HPAI) presents significant challenges in dental restorative treatments due to altered enamel structure.
• Understanding the bonding efficacy of different adhesive systems to compromised enamel is crucial for long-term restoration success.
• Self-etching (SE) and etch-and-rinse (ER) adhesives represent distinct approaches to dental adhesion, with varying interactions with tooth substrates.

Purpose of the Study:

• To compare the microtensile bond strengths (μTBS) of SE and ER adhesive systems on HPAI-affected enamel.
• To analyze the enamel etching patterns produced by SE and ER adhesives on HPAI-affected enamel using scanning electron microscopy (SEM).
• To evaluate the clinical relevance of these adhesive systems for restoring HPAI-affected teeth.

Main Methods:

• Extraction and preparation of HPAI-affected and healthy control molars for μTBS testing and SEM analysis.
• Application of two SE and two ER adhesive systems and composite resin to prepared enamel surfaces following manufacturer instructions.
• Fabrication of standardized 1-mm-thick sticks from bonded specimens for μTBS testing and SEM imaging of enamel etching patterns.

Main Results:

• No significant difference in μTBS was observed between SE and ER adhesive systems when bonded to HPAI-affected enamel (p > 0.05).
• A significant difference in bond strength was found between HPAI-affected enamel and healthy control enamel (p < 0.05).
• SEM analysis revealed mild intra- and inter-prismatic etching on HPAI enamel with orthophosphoric acid (ER), while SE primer created a slightly rough, grooved surface.

Conclusions:

• Both SE and ER adhesive systems demonstrate comparable bond strengths to HPAI-affected enamel.
• The findings suggest that current adhesive technologies can achieve adequate bonding to compromised enamel in HPAI.
• Further research may explore long-term durability and clinical outcomes of these adhesive systems in HPAI restorations.