Marginal Seal of Composite Restorations (Filtek Z250 – 3M/ESPE) with Various Bonding Systems –- Laboratory Evaluation

Objective: the aim of this in vitro study was to evaluate the tightness of the composite restorations (Filtek Z250 - 3MESPE) with various bonding systems. Methods: class V cavity preparations in 120 molars and premolars (12 groups - 10 samples in each) were restored with classical micro-hybrid composite Filtek Z250 (3MESPE) and 12 bonding systems: 4th generation EBS Multi (3MESPE), Scotchbond Multipurpose (3MESPE); 5th generation PQ1 (Ultradent), Gluma Comfort Bond (Haereus Kulzer), Fuji Bond LC (GC), Prime &Bond NT (Dentsply), Excite (Vivadent), Single Bond (3MESPE), Syntac Sprint (Vivadent), Opti Solo (Kerr); 6th generation Prompt–L-Pop (3MESPE), Etch&Prime 3.0 (Degussa). The restored teeth were stored in saline for 1 month, thermally stressed for 500 cycles and subjected to dye penetration testing (methylene blue 5%). Results: in the case of using Fuji Bond LC the size of microleakage was considerably reduced - microleakage index (relation between depth of dye penetration and size of the cavity) M=0,033. There was a tendency to better tightness for the bonding systems of 4th generation than for the other systems. The worse results were achieved for self-etching systems. There was significant statistical difference in microleakage among the groups as tested by one-way ANOVA and Scheffa (p<0,05). Conclusions: laboratory measurements revealed significantly less microleakage in restorations with bonding systems of 4th and 5th generation, then in restorations with self-etching systems.