Resin Cement Residue Removal Techniques: In Vitro Analysis of Marginal Defects and Discoloration Intensity Using...

Area of Science:

• Dental Materials Science
• Adhesive Dentistry
• Restorative Dentistry

Background:

• Proper removal of excess dental cement is crucial for the longevity and aesthetics of adhesively cemented restorations.
• In vitro studies are essential for evaluating the effects of different clinical techniques on marginal integrity and color stability.
• Understanding cement removal methods can optimize clinical protocols for ceramic veneers.

Purpose of the Study:

• To compare marginal defects and evaluate discoloration of ceramic veneers.
• To assess the impact of two distinct cement removal techniques (probing vs. brushing) on veneer margins.
• To analyze the effects of thermocycling on cement-related defects and discoloration.

Main Methods:

• IPS e.max CAD veneers were adhesively cemented to premolars using Panavia V5.
• Two cement removal groups: probing after tack-curing (3-5s) or brushing followed by full polymerization.
• Micro-computed tomography (micro-CT) assessed marginal defects before and after 5000 thermocycles (5-55°C); dye infiltration evaluated discoloration.

Main Results:

• Brushing resulted in significantly more marginal defects than probing before thermocycling (p=0.0161).
• Both techniques showed increased defects after thermocycling.
• Probing led to extensive discoloration in 55.56% of specimens, while brushing resulted in slight discoloration in 90% (p=0.008).

Conclusions:

• While brushing creates more initial marginal defects, it significantly reduces discoloration after thermocycling compared to probing.
• No correlation was found between the type of marginal defect and the degree of discoloration.
• The choice of cement removal technique impacts both marginal integrity and long-term color stability of ceramic veneers.