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Real-Time Imaging of Gap Progress during and after Composite Polymerization.
J Hayashi1, Y Shimada1,2, J Tagami1
11 Cariology and Operative Dentistry Department, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
Journal of Dental Research
|May 19, 2017
Summary
This study reveals that dental adhesive systems significantly influence interfacial gap formation in composite restorations, with some continuing to propagate even after light curing. OptiBond XTR and Clearfil SE Bond 2 demonstrated superior sealing performance compared to Bond Force and Scotchbond Universal Adhesive.
Area of Science:
- Dental Materials Science
- Biomaterials Engineering
- Restorative Dentistry
Background:
- Interfacial integrity is crucial for the longevity of dental composite restorations.
- Gap formation during and after polymerization can compromise restoration success and lead to secondary caries.
- Novel imaging techniques are needed to accurately assess these microstructural changes.
Purpose of the Study:
- To observe composite behavior and gap formation during light polymerization using swept-source optical coherence tomography (OCT).
- To compare the interfacial integrity of four adhesive systems (Bond Force, Scotchbond Universal Adhesive, OptiBond XTR, Clearfil SE Bond 2) in bovine teeth cavities.
- To quantify gap formation using 3D image analysis.
Main Methods:
- Forty cavities in bovine incisors were restored with four different adhesive systems and a flowable composite.
- Real-time OCT imaging was performed during and after light curing.
- 3D scanning and quantitative analysis of sealed enamel (E%) and dentin (D%) interfaces were conducted using Amira software.
Main Results:
- Gap formation was observed primarily on the dentin floor and progressed along the cavity floor, with varying timing and extent among groups.
- OptiBond XTR and Clearfil SE Bond 2 exhibited nearly perfect sealing performance on the dentin floor up to 10 minutes post-curing.
- Clearfil SE Bond 2 and OptiBond XTR showed significantly higher sealed interface percentages (E% and D%) compared to the other groups.
Conclusions:
- Real-time OCT and 3D quantification effectively assessed interfacial gap formation in composite restorations.
- The choice of adhesive system critically impacts the degree and progression of interfacial gap formation.
- Interfacial gaps continued to propagate after the completion of composite light curing, highlighting the importance of adhesive selection.
