Marginal leakage of amalgam and modern composite materials related to restorative techniques in class II cavity (Comparative study)


Background: Restoration of the gingival margin of Class II cavities with composite resin continues to be problematic,especially where no enamel exists for bonding to the gingival margin. The aim of study is to evaluate the marginalleakage at enamel and cementum margin of class II MOD cavities using amalgam restoration and moderncomposite restorations Filtek™ P90, Filtek™ Z250 XT (Nano Hybrid Universal Restorative) and SDR bulk fill with differentrestoratives techniques.Materials and method: Eighty sound maxillary first premolar teeth were collected and divided into two main groups,enamel group and cementum group (40 teeth) for each group. The enamel group was prepared with standardizedClass II MOD cavity with gingival margin (1 mm above C.E.J) on both box sides. While the cementum group with thegingival margin (1 mm below C.E.J) on both sides. The enamel and cementum groups were then subdivided intoeight subgroups for each (five teeth) with 10 boxes for each group. Subgroups within the main group namedaccording to materials and techniques that were used with it as following: Amalgam subgroup (Permite, SDI), SDRsubgroup (DENTSPLY) with bulk technique, Filtek™ P90 subgroup (3M ESPE) with three incremental techniques(Oblique, Horizontal and Centripetal technique), and Filtek™ Z250XT subgroup (3M ESPE) with three incrementaltechniques (Oblique, Horizontal and Centripetal technique).After specimens were stored in distilled water at 37°C for7 days. All specimens were subjected to thermocycling at (5° to 55 °C). Microleakage was evaluated bystereomicroscope (20 X). Data were analyzed statistically by Kruskal-Wallis test and Mann-Whitney U-test.Result: All experimental groups showed leakage at cementum more than enamel groups. SDR bulk fill subgroupshowed the highest marginal leakage among all experimental groups followed by Filtek™ Z250 XT subgroup withhorizontal technique at both enamel and cementum groups. Silorane and Filtek™ Z250 XT subgroups with obliquetechnique showed the least marginal leakage followed by centripetal technique at both enamel and cementumgroups. Amalgam restoration subgroup shows lesser leakage than SDR bulk fills subgroup significantly at both enameland cementum groups. While it show higher leakage than Silorane subgroup with oblique technique significantly atenamel margin only.Conclusion: The limiting factors for marginal leakage are technique and material dependent