Morphological assessment of the surface profile, mesiodistal diameter, and contact tightness of Class II composite restorations using three matrix systems: An in vitro study

CONTEXT: Sectional matrices and contact rings are valuable aids to establish proximal contact tightness in Class II composite restorations. AIMS: This study aims to evaluate the proximal contact area in Class II composite restorations using three matrix systems based on morphological analysis, mesiodistal (M-D) diameter and contact tightness. SUBJECTS AND METHODS: A standardized DO cavity was prepared in 30 plastic molar teeth. They were randomly divided into three groups (n = 10) and restored using Tetric N-Ceram composite material and three matrix systems – Saddle matrix, Palodent system, and Palodent Plus system. The quality of proximal contacts was assessed by measuring the maximum M-D diameter of the restored teeth using a digital caliper; the tightness of the proximal contact area using Unifloss and a standardized metal blade (30 μm). Qualitative assessment of contact morphology was done by visual means while quantitative assessment of contour was done using Medit scanner superimposing method and ExoCAD software. STATISTICAL ANALYSIS USED: One-way ANOVA test was used to compare the mean M-D diameter (in mm) in the occlusal third, middle third, and the proximal contact area between the three groups. Chi-square test was used to compare the proximal contact area tightness using the passage of Unifloss. The buccolingual and occluso-gingival morphology was also compared among the three groups. The level of significance (P value) was set at P < 0.05. RESULTS: For the occlusal and middle third, significantly larger diameters were achieved with the Palodent Plus system than with the Saddle matrix. More flat contours were seen in the case of the Saddle matrix than in the case of the Palodent system while the Palodent Plus system exhibited a minimal depth of concavity as determined by three-dimensional imaging of the contact morphology. CONCLUSIONS: Palodent Plus and Palodent matrix systems established superior contacts and contours than the Saddle matrix.