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Studies on posterior composite resins with special reference to class II restorations
1Department of Pedodontics, Faculty of Odontology, University of Göteborg, Sweden.
Swedish Dental Journal. Supplement
|January 1, 1990
Summary
Posterior composite resin restorations show good longevity for at least 4 years, with failures mainly due to fractures. Dentin bonding can reduce marginal leakage, but increased bacterial colonization requires attention.
Area of Science:
- Dental Materials Science
- Restorative Dentistry
- Clinical Oral Research
Background:
- Posterior composite resin restorations are widely used but their long-term clinical performance requires ongoing evaluation.
- Factors influencing longevity, such as wear, marginal integrity, and bacterial adhesion, are critical for clinical success.
Purpose of the Study:
- To investigate the longevity and clinical performance of experimental posterior composite resin restorations over a four-year period.
- To assess factors affecting restoration success, including wear, marginal leakage, bacterial colonization, and material conversion.
Main Methods:
- Clinical follow-up of Class I and Class II composite restorations using USPHS criteria over four years.
- In vitro and in vivo studies evaluating marginal leakage, occlusal wear (Leinfelder method), bacterial colonization (Streptococcus mutans), and degree of conversion.
Main Results:
- Seven percent of restorations failed within four years, primarily due to fractures and postoperative sensitivity.
- Occlusal wear rate averaged 34-40 microns/year. Occlusal loading increased marginal leakage, which was reduced by dentin bonding.
- In vivo conversion rates were higher than in vitro. Bacterial colonization was higher on restored surfaces than on sound tooth surfaces.
Conclusions:
- The tested posterior composite resins demonstrate a good prognosis for Class I and II restorations for at least four years.
- Clinical considerations include minimizing occlusal loading, utilizing dentin bonding, managing increased Streptococcus mutans risk, and performing regular follow-ups.