Reflections on teaching and learning during the omicron wave of the COVID-19 pandemic and economic inflation.

The pandemic and the rising living costs have affected teaching and learning practices. These changes have impacted teaching faculty and students alike. This article is an analytical reflection of our experiences of teaching and learning during the omicron wave of the pandemic and rising economic inflation. This paper highlights some of our key observations. The reflective process has challenged some of our preconceptions. It has also helped highlight some questions and contradictions on teaching and learning in this context which may provide a reference for future research.

Micro-shear bond strength of two all-in-one adhesive systems to unground fluorosed enamel.

The aim of this study was to evaluate the micro-shear bond strengths of two all-in-one adhesive systems to unground fluorosed enamel. Buccal surfaces of 24 normal and 24 moderately fluorosed teeth (Thylstrup and Fejerskov index, TFI=4-6) were bonded using G-Bond and Clearfil Tri-S Bond. The surfaces were then restored with a resin composite, stored for 24 hours in water, and tested for micro-shear bond strength (MSBS). Fracture modes, etching patterns, and adhesive interfaces were studied under a scanning electron microscope (SEM). Data were analyzed with two-way ANOVA, whereby no significant differences in MSBS were found among the four groups (p>0.05). Through SEM examination, it was shown that 1 microm of resin tag-like extensions had penetrated into the enamel for both adhesives at the enamel-adhesive interface. Based on the results obtained, it was concluded that MSBS was not influenced by the severity of fluorosis. Furthermore, there were no differences in enamel bond strength between G-Bond and Clearfil Tri-S Bond.

A clinical evaluation of the agar alginate combined impression: dimensional accuracy of dies by new master crown technique.

PURPOSE: To evaluate the dimensional accuracy of several impression methods including agar alginate combined impression in vivo; the marginal accuracy of stone dies was determined using a new electroformed master crown technique. MATERIALS AND METHODS: Cast cores with knife-edge and chamfer margins and electroformed master crowns were fabricated for 3 patients. Five impressions were taken of each preparation, using agar alginate combined impression and silicone impression materials. Dies were made after impression. The marginal fit of the master crown on each die was analyzed by four-way analysis of variance (ANOVA) and Tukey HSD test (p<0.05). RESULTS: The marginal fit of the master crown on the dies with chamfer margin was better than those with knife-edge margin for agar alginate combined impression. The shape of the margin did not affect the accuracy when silicone impression material was used. CONCLUSIONS: The results suggest that the agar alginate impression method is clinically acceptable for the chamfer margin, but shape of the margin may affect the dimensional accuracy of dies. The shape of the margin does not affect the accuracy of dies when silicone impression was used. Furthermore, the master crown made by electroforming technique could be useful for clinical evaluation of impression methods.