A NEW IMPROVED DESIGN OF INTERDENTAL TRANSPARENT WEDGES

Introduction: The objective of this study was the measurement and comparison of light output intensity at different points of lateral surfaces of conventional and novel designs of light-conducting interdental wedges.
Materials & Methods: This study was conducted on five groups of five wedges. Group 1 (TW): the Sakti transparent wedge; Group 2 (TW1): the Sakti transparent wedge with one Reflective External Surface (RES); Group 3 (TW2): the Sakti transparent wedge with two Reflective External Surfaces (2RES); Group 4 (LW): the Luciwedge; and Group 5 (LW2): the Luciwedge with two Reflective External Surfaces (2RES). Light output intensity of a light-curing source and six points at the lateral surfaces of each wedge were measured through a diaphragm with a 1 mm diameter which had a selenium photoelectric cell connected to a moving coil galvanometer. Statistical analyses were done using the Kruskal-Wallis test, Hoteling’s Trace, Duncan test and Mann-Whitney U test.
Results: There is a significant difference between light output intensity from different points of the groups. Light conduction efficacy of tested groups was significantly different and had decreased respectively TW2>LW>TW1>TW and LW2>LW).
Conclusion: 1) Due to low light conduction efficacy in tested groups, we cannot obtain optimum polymerization and properties of proximal light-cured restorations through any of the light-conducting wedges or conventional light-curing units. 2) A new wedge mediated light-curing technique (the "Two-Step Wedge Application Technique") for a complete and homogenous polymerization in proximal composite resin restorations was introduced. 3) Adding External Reflective Surfaces (RES) on transparent wedges caused light conduction efficacy improvement and the 2RES design was superior to the others. 4) According to this study, a new type of light-conducting wedge with perfectly transparent material as the body of the wedge together with the 2RES design can be recommended.