Background: zirconia is a crystalline dioxide of zirconium (ZrO2) white powder used in restorative esthetic dentistry as a superior additive to enhance mechanical properties. It is considered an intervention based on esthetic and functional properties to achieve the goal of restorative dentistry that blends art and science.
Objectives: This invitro study was conducted to assess and compare the fracture resistance of nano-zirconia-containing glass ionomer restorative materials and nano-zirconia-containing resin composite.
Methods: Maxillary premolars restored with two zirconia containing direct restorative materials (zirconfill composite and zirconomer improved glass ionomer) were evaluated for fracture resistance.
Forty freshly extracted maxillary intact premolars were collected and stored. After occlusal-mesial standardized cavity preparation, according to the used material teeth were randomly divided into two main groups (n=20). Each group is then divided into two subgroups (n=10) to be tested at different time intervals (24 hours and one week).
Data were collected, tabulated and statistically analyzed.
Results: Fracture resistance test showed a significant difference between zirconfill composite and zirconomer improved at day one-time interval (zirconfill showed better fracture resistance), while there was no significant difference on day 7.
Conclusion: Nano zirconia modification in glass-ionomer powder could enhance its dental application as a restorative material. Zirconia has a strengthening effect on the physico-mechanical properties of resin composite.
Clinical significance: for clinical success, clinicians must be aware of the properties of restorative materials and smart selection with accurate manipulation.