Evaluation of Vertical Discrepancies in Crown Seating Using Different Glass Ionomer Cement Volume: An In Vitro Study

Area of Science:

• Dental Materials Science
• Prosthodontics
• Biomaterials Engineering

Background:

• Accurate crown placement is crucial for long-term restoration success.
• Excess cement can lead to marginal discrepancies, affecting crown fit and longevity.
• Understanding cement volume's impact is key to optimizing cementation procedures.

Purpose of the Study:

• To evaluate vertical discrepancies in crown castings with varying glass ionomer cement volumes.
• To identify the optimal cement quantity for minimizing marginal discrepancies during crown cementation.

Main Methods:

• Sixty nickel-chromium (Ni-Cr) crown castings were divided into three groups based on cement volume: fully filled, half-filled, and internally brushed.
• A static load was applied during cementation, and vertical discrepancies were measured using stereomicroscopy and image analysis.
• Statistical analysis included one-way ANOVA and paired sample t-tests to compare groups.

Main Results:

• The internally brushed cement group exhibited the least mean vertical discrepancy (14.92±10.77 μm).
• This was significantly lower than the half-filled (28.42±12.45 μm) and fully-filled (58.50±20.91 μm) groups (P<0.05).

Conclusions:

• Cement volume is a critical factor influencing vertical marginal discrepancy in crown castings.
• Brushing glass ionomer cement onto internal crown surfaces results in smaller post-cementation vertical discrepancies, indicating a superior technique.