Eggshell membrane for DNA sexing of the endangered Maleo ( Macrocephalon maleo)

Effect of enamel-surface modifications on shear bond strength using different adhesive materials

BACKGROUND

This study aimed to investigate the effect of enamel-surface modifications on the shear bond strength between ceramic brackets bonded using different adhesive materials and the enamel surface and to identify the most suitable clinical adhesive and bonding method. Whether the non-acid-etching treatment met the clinical bond strength was also determined.

METHODS

A total of 108 extracted premolars were divided into nine groups (n = 12) based on the different enamel-surface modification techniques (acid etching, deproteinization, and wetting). Group 1 was bonded with Transbond™ XT adhesive, whereas groups 2-9 were bonded with resin-modified glass ionomer cement (RMGIC). The treatment methods for each group were as follows: groups 1 and 2, acid etching; group 3, acid etching and wetting; group 4, acid etching and deproteinization; group 5, acid etching, deproteinization, and wetting; group 6, deproteinization; group 7, deproteinization and wetting; group 8, without treatment; and group 9, wetting. The samples' shear bond strength was measured using an universal testing machine. Adhesive remnant index (ARI) was examined using a stereomicroscope. The enamel-surface morphology was observed with a scanning electron microscope. One-way ANOVA with Tukey's post-hoc test and chi-square test were used for statistical analysis, and p < 0.05 and α = 0.05 were considered statistically significant.

RESULTS

The ARIs of groups 1-5 and 6-9 were statistically significant (p = 0.000). The enamel surface of groups 1-5 was demineralized, and only a tiny amount of protein remained in groups 7 and 8, whereas a thick layer of protein remained in groups 8 and 9.

CONCLUSIONS

RMGIC adhesive did not damage the enamel surface and achieved the required clinical bond strength. The enamel surface was better treated with 5.25% sodium hypochlorite preferably under non-acid-etching conditions.

The Length Polymorphism of the 9th Intron in the Avian CHD1 Gene Allows Sex Determination in Some Species of Palaeognathae

In palaeognathous birds, several PCR-based methods and a range of genes and unknown genomic regions have been studied for the determination of sex. Many of these methods have proven to be unreliable, complex, expensive, and time-consuming. Even the most widely used PCR markers for sex typing in birds, the selected introns of the highly conserved CHD1 gene (primers P2/P8, 1237L/1272H, and 2550F/2718R), have rarely been effective in palaeognathous birds. In this study we used eight species of Palaeognathae to test three PCR markers: CHD1i9 (CHD1 gene intron 9) and NIPBLi16 (NIPBL gene intron 16) that performed properly as Psittaciformes sex differentiation markers, but have not yet been tested in Palaeognathae, as well as the CHD1iA intron (CHD1 gene intron 16), which so far has not been used effectively to sex palaeognathous birds. The results of our research indicate that the CHD1i9 marker effectively differentiates sex in four of the eight species we studied. In Rhea americana, Eudromia elegans, and Tinamus solitarius, the electrophoretic patterns of the amplicons obtained clearly indicate the sex of tested individuals, whereas in Crypturellus tataupa, sexing is possible based on poorly visible female specific bands. Additionally, we present and discuss the results of our in silico investigation on the applicability of CHD1i9 to sex other Palaeognathae that were not tested in this study.