Newer Possibilities for Proximal Box Elevation – Tooth Substrate and Comparison with Conventional Materials: An Ex-vivo Study

Background: Adhesive bonding in deep sub-gingival areas is a challenge due moist environment leading to poor marginal seal and microleakage in deep class II cavities. The deep margin elevation technique is advocated in such areas.

Aim: The aim of this study is to evaluate enamel, a natural substrate as an alternative material for deep margin elevation, and compare it with the resin-modified glass ionomer and composite material by evaluating microleakage at the tooth-restoration interface in Class II cavities.

Materials and Methods: For this study 21 patients having at least one tooth indicated for extraction and 7 patients having at least two teeth indicated for extraction were included.Class II cavities were prepared on the 28 teeth with proximal margins 1mm below the CEJ and were divided into 4 groups(n=7) Group 1: flowable composite was used for deep margin elevation(DME) up till 2mm above CEJ, Group 2: RMGIC was used for DMEup till 2 mm above CEJ, Group 3: enamel slab luted with RMGIC (for DME)up till 2mm above CEJ,enamel slab obtained from other seven teeth of same patient also indicated for extraction, Group 4(control): no intermediate material was used for margin elevation. Then the remaining part of the cavities were restored using the FILTEK P60. The prepared teeth were extracted after one week. The class II cavities were evaluated for microleakage using dye penetration method.

Results: RMGIC and enamel slab showed significantly less microleakage as compared to flowable composite and the control group. However there was insignificant difference between RMGIC and Enamel slab group. The control group exhibited highest microleakage as compared to all the other groups.

Conclusion: RMGIC and enamel slab exhibit least microleakage when used as materials for deep-margin elevation.