In vitro microleakage of luting cements and crown foundation material

Area of Science:

• Dental Materials Science
• Restorative Dentistry
• Biomaterials Engineering

Background:

• Microleakage around dental restorations compromises long-term prognosis.
• Evaluating cement and foundation performance is crucial for durable restorations.

Purpose of the Study:

• To assess microleakage of zinc phosphate cement versus resin-reinforced glass ionomer cement.
• To compare microleakage with three foundation types under dry and contaminated conditions.

Main Methods:

• 140 extracted molars underwent Class II cavity preparations and crown preparations.
• Restorations included amalgam/varnish, amalgam/bonding agent, composite/bonding agent, and controls.
• Cements tested were zinc phosphate and resin-reinforced glass ionomer under dry/contaminated conditions.
• Specimens were thermocycled, immersed in dye, sectioned, and photomicrographed to measure microleakage.

Main Results:

• Resin-reinforced glass ionomer cement exhibited less microleakage than zinc phosphate cement under both ideal and contaminated conditions.
• Foundations using dentinal bonding agents (amalgam, composite) showed minimal microleakage in ideal conditions.
• The absence of a foundation resulted in the highest microleakage.

Conclusions:

• Resin-reinforced glass ionomer cement offers superior marginal integrity compared to zinc phosphate cement.
• The use of dentinal bonding agents with amalgam or composite foundations enhances sealing under ideal conditions.
• Foundation material and cement type significantly influence microleakage in cemented restorations.