Editorial: Advanced Materials for the Restoration and Reconstruction of Dental Functions

Comparative evaluation of bond strength and color stability of polyetheretherketone and zirconia layered with indirect composite before and after thermocycling: An in vitro study

AIM

This study investigates the interaction of zirconia and polyetheretherketone (PEEK) with indirect composite in fixed dental prostheses. This investigation aimed to assess the shear bond strength (SBS) and color stability of zirconia and PEEK before and after aging, addressing critical concerns in dental restorative applications.

SETTINGS AND DESIGN

The current in vitro study used 96 samples, 48 of which were divided into two groups, zirconia and PEEK, before and after thermocycling. A dual-axis chewing simulator was used for thermocycling. SBS was measured using a universal testing machine, and color stability was checked using a reflective spectrophotometer.

MATERIALS AND METHODS

Ninety-six samples were categorized into zirconia and PEEK groups, each with subgroups undergoing thermocycling. Samples were prepared using computer-aided design/computer-aided manufacturing milling and veneered with composite resin. Thermocycling involved 10,000 cycles, simulating stress levels equivalent to approximately 1 year of clinical use. SBS was assessed using standardized tests. Stereomicroscopic analysis was performed to evaluate the type of failure. Color stability of the core materials with indirect composite was done using a spectrophotometer before and after aging.

STATISTICAL ANALYSIS USED

Statistical analysis included paired t-tests and independent t-tests in SPSS software.

RESULTS

The results revealed that SBS values for composite on PEEK decreased from 13.86 ± 0.164 MPa before thermocycling to 13.46 ± 0.185 MPa after thermocycling, with a significant difference (P < 0.005). However, both pre- and postthermocycling values for PEEK were higher than zirconia. The t-test confirmed the lower bond strength of composite to zirconia, with a noteworthy improvement after aging. Stereomicroscopic images revealed adhesive failure for the zirconia group and mixed (adhesive and cohesive) failure for the PEEK group. ΔE values were 3.21 ± 0.127 and 2.93 ± 0.142 for zirconia and PEEK groups, respectively (P < 0.005).

CONCLUSION

Within the limitations of this study, it can be deduced that PEEK is a feasible substitute for zirconia when used in conjunction with indirect composite for the fabrication of dental prostheses.

Beyond the Needle: A Comparative Evaluation of Silk Sutures and Cyanoacrylate for Periodontal Flap Closure

Introduction As the incidence of periodontal diseases continues to surge, there is a concurrent elevation in the demand for periodontal treatment. Periodontal surgical therapy is done to control and eliminate disease activity. Conventionally, silk sutures have been considered the gold standard for post-operative flap closure that leads to biofilm accumulation and tissue trauma. Cyanoacrylates are alternate options to avoid the limitations. Objective The objective of the study was to assess clinical outcomes by comparing the healing after periodontal flap surgery when secured with 3-0 braided silk suture versus cyanoacrylate. Methodology Twenty surgical sites from 10 patients with moderate to severe periodontitis were selected and randomly divided into two groups after phase-1 therapy: the test group (isoamyl 2-cyanoacrylate) and the control group (3-0 silk braided suture). Post-operative wound healing, pain assessment using a verbal rating scale (VRS), and analgesic tablets taken were evaluated on the third, fifth, seventh, and 14th days. Statistical analysis was done using the ANOVA test with the post-hoc Bonferroni test. Results There was no statistically significant difference between the VRS and wound healing index at different levels of intervals during intergroup comparison, but the number of analgesics consumed post-operatively was less in the test group as compared to the control group. Conclusion The present study concluded that isoamyl 2-cyanoacrylate can be used as an alternative to conventional silk sutures as it decreases post-operative pain and discomfort.

Recent advances in NIR-II fluorescence based theranostic approaches for glioma

Gliomas are among the most common malignant tumors in the central nervous system and lead to poor life expectancy. However, the effective treatment of gliomas remains a considerable challenge. The recent development of near infrared (NIR) II (1000-1700 nm) theranostic agents has led to powerful strategies in diagnosis, targeted delivery of drugs, and accurate therapy. Because of the high capacity of NIR-II light in deep tissue penetration, improved spatiotemporal resolution can be achieved to facilitate the in vivo detection of gliomas via fluorescence imaging, and high contrast fluorescence imaging guided surgery can be realized. In addition to the precise imaging of tumors, drug delivery nano-platforms with NIR-II agents also allow the delivery process to be monitored in real-time. In addition, the combination of targeted drug delivery, photodynamic therapy, and photothermal therapy in the NIR region significantly improves the therapeutic effect against gliomas. Thus, this mini-review summarizes the recent developments in NIR-II fluorescence-based theranostic agents for glioma treatment.