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Five-Year Clinical Performance of Complex Class II Resin Composite and Amalgam Restorations-A Retrospective Study
Maria Jacinta M C Santos1, Heleine Maria C Rêgo1, Imad Siddique1
1Division of Restorative Dentistry, Schulich School of Medicine and Dentistry, The University of Western Ontario, Room # 0149, Dental Sciences Building, London, ON N6A 5C1, Canada.
This study found that both resin composite (RC) and amalgam (AM) restorations for complex Class II cavities demonstrated similar clinical performance after five years. While amalgam had more secondary caries, resin composite experienced a higher rate of fractures.
Area of Science:
- Restorative Dentistry
- Dental Materials Science
- Clinical Dental Research
Background:
- Complex Class II restorations are frequently performed in dental practice.
- Evaluating the long-term clinical success of different restorative materials is crucial for evidence-based decision-making.
- Resin composite (RC) and amalgam (AM) are common materials for posterior restorations, each with distinct properties.
Purpose of the Study:
- To compare the five-year clinical performance of complex Class II resin composite (RC) and amalgam (AM) restorations.
- To identify failure modes and assess clinical acceptability using USPHS criteria.
Main Methods:
- Retrospective evaluation of 119 complex Class II restorations placed by dental students.
- Assessment using United States Public Health Service (USPHS) criteria after a five-year period.
- Statistical analysis including Chi-square, Mann-Whitney, and Wilcoxon tests (p<0.05).
Main Results:
- After five years, 78% of RC and 76.8% of AM restorations were clinically satisfactory.
- Amalgam failures were mainly due to secondary caries (10.1%) and defective marginal adaptation (8.7%).
- Resin composite failures were primarily related to restoration fracture (16%) and defective marginal adaptation (8.2%).
- Secondary caries was significantly higher for AM (10.1% vs 0%, p=0.0415), while fractures were higher for RC (16% vs 4.3%, p=0.05).
- Amalgam restorations showed significantly better anatomical form (49.3% Alfa vs 22.4% Alfa, p=0.0005).
Conclusions:
- Complex Class II resin composite and amalgam restorations exhibit comparable clinical performance over five years.
- Material selection should consider the specific failure modes observed for each material, such as secondary caries for amalgam and fracture for resin composite.
- Further research may explore strategies to mitigate the respective weaknesses of each material.
