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Correlation between margin fit and microleakage in complete crowns cemented with three luting agents
Paulo Henrique Orlato Rossetti1, Accacio Lins do Valle, Ricardo Marins de Carvalho
1Oral Rehabilitation Program, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil.
Journal of Applied Oral Science : Revista FOB
|December 18, 2008
Summary
This study found no strong correlation between dental crown margin fit and microleakage. However, resin-modified glass-ionomer (RMGI) and resin-based cement (RC) showed significantly less microleakage than zinc phosphate (ZP) cement.
Area of Science:
- Dental Materials Science
- Prosthodontics
- Biomaterials
Background:
- Microleakage at the tooth-cement interface is a clinical concern, potentially linked to marginal misfit of dental restorations.
- Traditional microleakage assessment methods can be labor-intensive and time-consuming.
- Evaluating the correlation between in vitro margin fit and microleakage is crucial for optimizing luting agents and techniques.
Purpose of the Study:
- To investigate the correlation between in vitro margin fit and microleakage for complete crowns.
- To compare the microleakage of three different luting agents: zinc phosphate (ZP), resin-modified glass-ionomer (RMGI), and resin-based cement (RC).
- To assess a novel microleakage technique in relation to margin fit.
Main Methods:
- Thirty human premolars were prepared for full-coverage crowns with specific preparation parameters (6° convergence, 1.2 mm chamfer margin, 1.5 mm occlusal reduction).
- Nickel-chromium cast crowns were cemented using ZP, RMGI, or RC luting agents.
- Margin fit (seating discrepancy and marginal gap) was measured microscopically. Following thermal cycling, microleakage was assessed after longitudinal sectioning at x100 magnification.
Main Results:
- No statistically significant correlation was found between margin fit parameters (seating discrepancy and marginal gap) and microleakage scores (Spearman's test, p>0.05).
- Marginal microleakage scores varied significantly among the luting agents (p<0.001).
- Resin-modified glass-ionomer (RMGI) and resin-based cement (RC) exhibited significantly lower microleakage scores (0.35 and 0.12, respectively) compared to zinc phosphate (ZP) cement (3.02).
Conclusions:
- Margin fit parameters did not demonstrate a strong correlation with microleakage in this study.
- Cast crowns cemented with RMGI and RC showed superior performance with lower microleakage compared to ZP cement.
- The findings suggest that luting agent selection plays a more critical role in preventing microleakage than marginal fit alone.
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