In vitro marginal microleakage associated with five dentine bonding systems and associated composite restorations

Fifty sound premolar teeth, extracted for orthodontic purposes and stored at room temperature in physiological saline since extraction, were prepared with a standardized minimal two-surface Class II cavity. The teeth were then ascribed randomly to five groups, each of ten teeth. Each of four groups was restored using a different dentine bonding system and the associated posterior composite resin according to the manufacturer's instructions. The fifth group was restored with Superbond C & B dentine bonding system and Occlusin composite. After immersion in de-ionized water for at least 7 days, the teeth were sealed with nail varnish to within 1 mm of the margin of the restoration. The teeth were then immersed in 5 per cent buffered Eosin for 48 h. Following mesiodistal sectioning the sections were photographed and subjected to image analysis to establish the length of dye penetration at the tooth/restoration interface and the amount of dye penetration into the crown dentine. Tripton/Occlusin and XR Bond/Herculite XR groups showed a significantly (P less than 0.05) smaller amount of leakage than Gluma/Lumifor or Scotchbond 2/P50 combinations when assessed as a percentage of the tooth/restoration interface exhibiting leakage. When the percentage of crown dentine showing dye penetration was considered, the Tripton/Occlusin group showed less leakage than the other material combinations. It is concluded that Tripton, when used with the recommended composite, will allow significantly less microleakage than Gluma/Lumifor, Scotchbond 2/P50 or Superbond C & B/Occlusin combinations and a similar amount to XR Bond/Herculite XR in vitro.