Marginal integrity of different resin-based composites for posterior teeth: an in vitro dye-penetration study on eight resin-composite and compomer-/adhesive combinations with a particular look at the additional use of flow-composites

Objective: To determine improvements in marginal adaptation of resin-based composite restorative systems by means of flow-composites (Solitaire 2/Gluma Solid Bond, Solitaire 2/Flow Line/Gluma Solid Bond, Point 4/Optibond Solo Plus, Point 4/Revolution/Optibond Solo Plus) and to determine the equality of simplified bonding systems (Solitaire 2/Gluma Comfort Bond, Tetric Ceram/Tetric Flow[Excite, Dyract AP/Prime & Bond NT/NRC, Pertac II/Prompt-L-Pop) in marginal gap formation. Methods: The marginal dye penetration (2% methylene-blue) was investigated separately for the approximal boxes of Class II modcavities with one cervical margin of the approximal box within enamel, the other within cementum. The surface analysis determined the percentage of dye-penetrated cervical and lateral margins of the approximal boxes, while the in depth investigation reported the mean dye penetration (mm) at both different cervical margins. Results: After thermocycling (5000 X, 5-55degreesC) the percentage of dye penetration at the cervical cementum margins ranged from 16.5 +/- 5.9% (Solitaire/Flow Line/Gluma Solid Bond) to 82.8 +/- 5.7% (Pertac II/Prompt L-Pop), for the cervical enamel margins from 10.1 +/- 5.2% (Dyract AP/NRC/P & B NT) to 72.7 +/- 7.9% (Pertac II/Prompt L-Pop), and for the lateral enamel margins of the approximal boxes from 4.8 +/- 2.3% (Dyract AP/NRC/P & B NT) to 53.9 +/- 6.8% (Pertac II/Prompt L-Pop). In the in-depth dye penetration investigation the mean dye penetration ranged from 0.2 +/- 0.2 mm (Point 4/Revolution/Optibond Solo Plus) to 1.7 +/- 0.2 mm (Pertac II/Prompt L-Pop) at the cementum margins. At the enamel margins only Pertac II/Prompt L-Pop and Solitaire 2/Gluma Solid Bond showed mean in depth dye-penetrations deeper than 0.1 mm. Significance: Pertac II/Prompt-L-Pop showed a statistically significant (significance level alpha = 0.05, Wilcoxon test) higher percentage of dye-penetrated margins than most of the other restorative systems. (C) 2002 Academy of Dental Materials. Published by Elsevier Science Ltd. All rights reserved.