Fracture resistance of maxillary premolars with mod cavities restored with Zirconomer: An in vitro comparative study

Aim: To test the fracture resistance of maxillary premolars with MOD cavities restored with a new Zirconia reinforced Glass Ionomer Cement (Zirconomer) and to compare it with other conventional posterior restorative materials like GIC and Amalgam. Materials and Methodology: Freshly extracted forty intact, non-carious human maxillary premolars were collected and stored in distilled water. The teeth were randomly divided into 2 Control groups with 5 teeth each (n=5) and 3 experimental groups with 10 teeth each (n=10). Group I: No cavities were prepared (Positive control). Group II : Class II MOD cavities were prepared but not restored (Negative control). Group III: Cavities were restored with Amalgam (DPI). Group IV: Cavities were restored with Glass Ionomer Cement (GC). Group V: Cavities were restored with Zirconomer (Shofu). Fracture resistance was tested with a steel ball of 4mm diameter with a cross head speed of 1mm/min in Universal Testing Machine. Statistical analysis was done using One-Way Analysis Of Variance (ANOVA) and Tukey test Results: Teeth restored with Zirconomer were most resistant to fracture load followed by Amalgam (p>0.05) and Glass Ionomer Cement (p<0.05), suggesting Zirconomer can be used as a potential substitute for amalgam in posterior teeth.