Effect of a functional monomer (MDP) on the enamel bond durability of single‐step self‐etch adhesives

The present study aimed to determine the effect of the functional monomer, 10‐methacryloxydecyl dihydrogen phosphate (MDP), on the enamel bond durability of single‐step self‐etch adhesives through integrating fatigue testing and long‐term water storage. An MDP‐containing self‐etch adhesive, Clearfil Bond SE ONE (SE), and an experimental adhesive, MDP‐free (MF), which comprised the same ingredients as SE apart from MDP, were used. Shear bond strength (SBS) and shear fatigue strength (SFS) were measured with or without phosphoric acid pre‐etching. The specimens were stored in distilled water for 24 h, 6 months, or 1 yr. Although similar SBS and SFS values were obtained for SE with pre‐etching and for MF after 24 h of storage in distilled water, SE with pre‐etching showed higher SBS and SFS values than MF after storage in water for 6 months or 1 yr. Regardless of the pre‐etching procedure, SE showed higher SBS and SFS values after 6 months of storage in distilled water than after 24 h or 1 yr. To conclude, MDP might play an important role in enhancing not only bond strength but also bond durability with respect to repeated subcritical loading after long‐term water storage.     

Comparison between universal adhesives and two‐step self‐etch adhesives in terms of dentin bond fatigue durability in self‐etch mode

This aim of this study was to compare universal adhesives and two‐step self‐etch adhesives in terms of dentin bond fatigue durability in self‐etch mode. Three universal adhesives – Clearfil Universal, G‐Premio Bond, and Scotchbond Universal Adhesive – and three‐two‐step self‐etch adhesives – Clearfil SE Bond, Clearfil SE Bond 2, and OptiBond XTR – were used. The initial shear bond strength and shear fatigue strength of resin composite bonded to adhesive on dentin in self‐etch mode were determined. Scanning electron microscopy observations of fracture surfaces after bond strength tests were also made. The initial shear bond strength of universal adhesives was material dependent, unlike that of two‐step self‐etch adhesives. The shear fatigue strength of Scotchbond Universal Adhesive was not significantly different from that of two‐step self‐etch adhesives, unlike the other universal adhesives. The shear fatigue strength of universal adhesives differed depending on the type of adhesive, unlike those of two‐step self‐etch adhesives. The results of this study encourage the continued use of two‐step self‐etch adhesive over some universal adhesives but suggest that changes to the composition of universal adhesives may lead to a dentin bond fatigue durability similar to that of two‐step self‐etch adhesives.     

Person misfit on the Inventory of Depressive Symptomatology: Low quality self‐report or true atypical symptom profile?

Person misfit on a self‐report measure refers to a response pattern that is unlikely given a theoretical measurement model. Person misfit may reflect low quality self‐report data, for example due to random responding or misunderstanding of items. However, recent research in the context of psychopathology suggests that person misfit may reflect atypical symptom profiles that have implications for diagnosis or treatment. We followed‐up on Wanders et al. (Journal of Affective Disorders, 180, 36–43, 2015) who investigated person misfit on the Inventory of Depressive Symptomatology (IDS) in the Netherlands Study of Depression and Anxiety (n = 2,981). Our goal was to investigate the extent to which misfit on the IDS reflects low‐quality self‐report patterns and the extent to which it reflects true atypical symptom profiles. Regression analysis showed that person misfit related more strongly to self‐report quality indicators than to variables quantifying theoretically‐derived atypical symptom profiles. A data‐driven atypical symptom profile explained most variance in person misfit, suggesting that person misfit on the IDS mainly reflects a sample‐ and questionnaire‐specific atypical symptom profile. We concluded that person‐fit statistics are useful for detecting IDS scores that may not be valid. Further research is necessary to support the interpretation of person misfit as reflecting a meaningful atypical symptom combination.     

Influence of duration of phosphoric acid pre‐etching on bond durability of universal adhesives and surface free‐energy characteristics of enamel

The purpose of this study was to evaluate the influence of duration of phosphoric acid pre‐etching on the bond durability of universal adhesives and the surface free‐energy characteristics of enamel. Three universal adhesives and extracted human molars were used. Two no‐pre‐etching groups were prepared: ground enamel; and enamel after ultrasonic cleaning with distilled water for 30 s to remove the smear layer. Four pre‐etching groups were prepared: enamel pre‐etched with phosphoric acid for 3, 5, 10, and 15 s. Shear bond strength (SBS) values of universal adhesive after no thermal cycling and after 30,000 or 60,000 thermal cycles, and surface free‐energy values of enamel surfaces, calculated from contact angle measurements, were determined. The specimens that had been pre‐etched showed significantly higher SBS and surface free‐energy values than the specimens that had not been pre‐etched, regardless of the aging condition and adhesive type. The SBS and surface free‐energy values did not increase for pre‐etching times of longer than 3 s. There were no significant differences in SBS values and surface free‐energy characteristics between the specimens with and without a smear layer. The results of this study suggest that phosphoric acid pre‐etching of enamel improves the bond durability of universal adhesives and the surface free‐energy characteristics of enamel, but these bonding properties do not increase for phosphoric acid pre‐etching times of longer than 3 s.     

Benefits and Burdens of Using a SNP Array in Pregnancies at Increased Risk for the Common Aneuploidies

We present the nature of pathogenic SNP array findings in pregnancies without ultrasound (US) abnormalities and show the additional diagnostic value of SNP array as compared with rapid aneuploidy detection and karyotyping. 1,330 prenatal samples were investigated with a 0.5‐Mb SNP array after the exclusion of the most common aneuploidies. In 2.7% (36/1,330) of the cases, pathogenic chromosome aberrations were found; a microscopically detectable abnormality in 0.7% and a submicroscopic aberration in 2%. Our results show that in addition to the age‐ or screening‐related aneuploidy risk, in pregnancies without US abnormalities, there is a risk of 1:148 (9/1,330) for a (sub)microscopic abnormality associated with an early‐onset often severe disease, 1:222 (6/1,330) for a submicroscopic aberration causing an early‐onset disease, 1:74 (18/1,330) for carrying a susceptibility locus for a neurodevelopmental disorder, and 1:443 (3/1,330) for a late‐onset disorder (hereditary neuropathy with liability to pressure palsies in all three cases). These risk figures are important for adequate pretest counseling so that prospective parents can make informed individualized choices between targeted prenatal testing and broad testing with SNP array. Based on our results, we believe if invasive testing is performed, SNP array should be the preferred cytogenetic technique irrespective of the indication.     

The contribution of the individual blood elements to the variability of thromboelastographic measures

BACKGROUND

Thromboelastography (TEG) is widely advocated as a rapid method for obtaining critical blood coagulation data to guide resuscitation, but the method suffers well‐known limits in sensitivity, repeatability, and interpretability.

STUDY DESIGN AND METHODS

Mixtures of fresh human blood components were prepared that represent the range of blood element concentrations seen in health and disease and after injury. These mixtures were tested in a TEG device after kaolin, tissue factor and phospholipid, or tissue factor and phospholipid with abciximab activation. The results were measured as reproducibility and nonlinear effects in regression analysis and evaluated for interpretability.

RESULTS

Clot strength was associated with increased platelet (PLT) content and plasma fibrinogen concentration and content. Increasing hematocrit (Hct) reduced while increasing PLT or plasma concentration increased TEG clot strength. The abciximab dose used to block PLT activity did not fully inhibit the PLT contribution to clot strength. Clot strength is logarithmically correlated in the absence and linearly correlated to PLT concentration in the presence of abciximab. TEG clot strength with or without abciximab is dependent on Hct, PLT, and plasma (fibrinogen) concentrations in complex patterns.

CONCLUSION

Interpretation of TEG variables is limited without knowledge of the concentration of the blood components present. When “normal” TEG values are known for a certain PLT‐plasma‐red blood cell concentration, the assay can be used to assess PLT and plasma function in coagulation. The TEG “functional fibrinogen” assay should be used only as a gross estimate of the fibrinogen concentration in whole blood.