Marginal microleakage in cemented complete crowns.

Area of Science:

• Dental Materials Science
• Prosthodontics
• Biomaterials

Background:

• Marginal leakage in dental restorations can lead to secondary caries and pulpal issues.
• Zinc phosphate cement is a commonly used luting agent for complete crown castings.
• Protective agents are sometimes applied to minimize cement-related complications.

Purpose of the Study:

• To evaluate the efficacy of different protective agents in preventing marginal leakage around complete crowns cemented with zinc phosphate cement.
• To assess the influence of protective agents on the penetration of radioisotopes (131INa) into the crown margins.
• To determine the impact of crown adaptation and cement film thickness on marginal leakage.

Main Methods:

• An in vivo study utilizing 131INa to quantify marginal leakage around complete crown castings.
• Comparison of marginal leakage with zinc phosphate cement alone versus cement with various protective agents applied to margins.
• Evaluation of leakage at two time points: 1 hour and 21 days post-cementation.

Main Results:

• Significant differences in 131INa marginal leakage were observed based on the protective material used.
• Two layers of cavity varnish demonstrated the most effective reduction in marginal leakage.
• Crown adaptation and cement film thickness were identified as factors influencing the extent of marginal leakage.
• No significant difference in leakage was found between the 1-hour and 21-day test periods.

Conclusions:

• Cavity varnish application, specifically two layers, is a recommended preventive measure against marginal leakage with zinc phosphate cement.
• Optimizing crown adaptation and controlling cement film thickness are crucial for minimizing marginal leakage.
• The protective effect of cavity varnish appears consistent over short and medium-term periods.