An Invitro Chewing Simulation Study Comparing the Wear Resistance Behavior of Polyetheretherketone-Layered Composite Crown and Ceramic-Layered Zirconia Crown.

OBJECTIVE: This study aimed to compare the wear resistance and color stability of fixed dental prostheses (FDPs) fabricated using two different materials: zirconia veneered with feldspathic porcelain and polyetheretherketone (PEEK) veneered with indirect composite. The assessment included samples subjected to thermocycling and wear simulation. METHODS: Two groups of FDPs were examined: one made of zirconia veneered with feldspathic porcelain (control and thermocycled) and the other made of PEEK veneered with indirect composite (worn and thermocycled). The samples were evaluated for wear resistance, antagonist wear, and color stability. Computer-aided design (CAD) software and a digital spectrophotometer were used for analysis. RESULTS: Zirconia veneered with porcelain demonstrated higher wear resistance compared to PEEK veneered with indirect composite. PEEK veneered with indirect composite exhibited significantly lower antagonist wear, indicating a protective effect on opposing teeth. There was no significant difference in color stability between the two groups, even after subjecting them to thermocycling and wear simulation. CONCLUSION: The study concludes that FDPs fabricated with PEEK veneered with indirect composite may have lower wear resistance compared to zirconia veneered with porcelain. However, PEEK FDPs appear to be safer for antagonists due to reduced antagonist wear. Importantly, both materials exhibited similar color stability, making PEEK a viable alternative for FDPs when aesthetic appeal and antagonist protection are primary considerations.

Green Synthesis of Titanium Oxide Nanoparticles With Rosemary and Ginger and Their Bactericidal Action Against Staphylococcus aureus.

INTRODUCTION: Titanium oxide (TiO2) nanoparticles (NPs) have significantly proved to be highly useful in restorative materials, dental adhesives, sealants, cements, and other dental applications to prevent microbial colonization and reduce the risk of infections. The present study was aimed at developing a dental material with antibacterial properties by combining titanium oxide NPs using ginger and rosemary extracts. MATERIALS AND METHODS: The formulation was prepared using rosemary and ginger, mediated by TiO2 NPs. The preparation was then introduced into the wells of a microplate consisting of cultured Staphylococcus aureus and was kept for incubation for four hours. To record the minimum inhibitory concentration, the test solution was added into Kimble tubes consisting of Muller-Hinton broth. The results obtained were statistically analyzed using one-way ANOVA. RESULT: Increasing concentration led to decreased optical density, indicating bactericidal effects. Significantly lower optical density values were observed in decreasing order among the test samples (25, 50, and 100 µL) compared to control and antibiotic groups against Streptococcus, highlighting the potent antibacterial and antibiofilm properties of the greenly generated combination of titanium oxide NPs with herbs. This was also confirmed by moderate minimum inhibitory concentration at 100 µL. CONCLUSION: The present study suggests that there is a bactericidal process at play, leading to a reduction in the overall bacterial count. It can be concluded that the ginger and rosemary-mediated titanium oxide NPs serve as potential antibacterial agents against S. aureus. This study can be used as a preliminary study, and further studies can be conducted to use this formulation in the field of medicine.