Three Different Matrix Systems’ Contact Tightness in Class-II Cavities

Objectives: The purpose of this study was to evaluate the contact tightness of restorations applied to cavity three different matrix systems and two different composite resin materials utilized in the posterior region.
Methods: In the present study, 144 acrylic molar teeth were used, and standardized Class-II MO cavities with the same features were prepared on acrylic jaw for phantom head. The entire procedure was performed by a single operator. Teeth were divided into three groups as two different sectional matrix systems (Ivory and Palodent) and one circumferential matrix (Tofflemire) system. Depends on the composite resin, which microhybrid and bulkfill composite, each group divided two subgroups. Groups were as follows; Group 1: Tofflemire matrix-microhybrid composite; Group 2: Tofflemire matrix-bulkfill composite; Group 3: Ivory matrix-microhybrid composite; Group 4 :Ivory matrix-bulkfill composite; Group 5 :Palodent matrix-microhybit composite; Group 6 :Palodent matrix-bulkfill composite. Then, the microhybrid composite was applied with incremental technique, while the bulkfill composites were applied in single layer. Before the restoration pre-contact tightness and after the restoration post-contact tightness were measured on the teeth according to the World Dental Federation (FDI) criteria by both the operating physician and a specialist who had no knowledge of the procedures. Data were evaluated with Kruskall-Wallis and Tamhane tests. Cohen’s Kappa coefficient was illustrated for inter-rater.
Results: The initial contact tightness agreement between the two observers was substantial (0.638) and the final contact tightness agreement was fair (0.344). There was no significant difference in the contact tightness between the palodent matrix and the ivory matrix (p>0.05), but significant difference was found between them and the tofflermire matrix (respectively, p<0.001, p<0.001).
Conclusions: Using a sectional matrix system might be provides superior contact tightness compared to using a circumferential matrix system. Due to our results are in vitro and may not be possible to compare with under clinical conditions.