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Resin composite shrinkage and marginal adaptation with different pulse-delay light curing protocols.
Ivo Krejci1, Milanka Planinic, Minos Stavridakis
1Division of Cariology and Endodontology, School of Dental Medicine, University of Geneva, Geneva, Switzerland. Ivo.Krejci@medicine.unige.ch
European Journal of Oral Sciences
|December 6, 2005
Summary
This study measured light curing shrinkage and marginal adaptation in dental restorations. Pulse-delay curing showed lower shrinkage but comparable marginal adaptation in dentin, though enamel adaptation decreased post-loading.
Area of Science:
- Dental Materials Science
- Restorative Dentistry
Background:
- Light curing is essential for dental restorations, but polymerization shrinkage can compromise marginal integrity.
- Pulse-delay light curing strategies aim to reduce shrinkage stress and improve restoration outcomes.
Purpose of the Study:
- To quantify shrinkage induced by various pulse-delay light curing methods.
- To evaluate the impact of these methods on the marginal adaptation of Class V restorations in enamel and dentin.
Main Methods:
- Eight groups were tested for dynamic linear displacement and shrinkage force using a fine hybrid composite.
- The optimal pulse-delay group was compared to a control for marginal adaptation (Class V restorations) before and after thermal/mechanical loading.
Main Results:
- Significant differences in shrinkage properties were observed among pulse-delay groups, with one group exhibiting minimal shrinkage.
- No significant difference in marginal adaptation was found in dentin between the best pulse-delay group and the control.
- A significantly lower percentage of continuous margin was observed in enamel for the pulse-delay group after loading.
Conclusions:
- Pulse-delay light curing can reduce polymerization shrinkage in dental composites.
- While effective in dentin, pulse-delay curing may negatively impact marginal adaptation in enamel under challenging conditions.