Microleakage and adaptation of Class II packable resin-based composites using incremental or bulk filling techniques

Area of Science:

• Dental Materials Science
• Restorative Dentistry
• Biomaterials

Background:

• Gingival margin integrity is crucial for the longevity of Class II restorations.
• Packable resin-based composites (RBCs) are commonly used for posterior restorations.
• Microleakage at the gingival margin can lead to secondary caries and pulpal issues.

Purpose of the Study:

• To compare the gingival margin sealing ability of three packable RBC systems: ALERT, SureFil, and Solitaire.
• To evaluate the effect of incremental-cure versus bulk-cure techniques on microleakage.
• To assess sealing efficacy when the gingival margin is apical to the cementoenamel junction.

Main Methods:

• Sixty extracted human premolars with Class II preparations were restored using ALERT, SureFil, or Solitaire packable RBCs.
• Restorations were placed using either an incremental-cure or a bulk-cure technique.
• Specimens underwent thermocycling, staining, sectioning, and light microscopic evaluation for gingival margin microleakage.

Main Results:

• All tested packable RBC systems exhibited microleakage at the gingival margin.
• No statistically significant difference in microleakage was observed between incremental-cure and bulk-cure techniques for any system.
• The ALERT system demonstrated significantly less microleakage compared to SureFil and Solitaire.

Conclusions:

• None of the evaluated packable resin-based composite systems completely sealed the gingival margin in Class II preparations.
• The placement and curing technique (incremental vs. bulk) did not significantly influence microleakage.
• ALERT appears to offer superior marginal sealing properties compared to SureFil and Solitaire in this study.