Effect of oxygen inhibition of self-etching adhesives on enamel-dentin polymer bond

PURPOSE: To determine effects of light curing of self-etching adhesives under ambient air or nitrogen on inhibition depths, enamel and dentin bond strengths, and marginal adaptation in dentin cavities. MATERIALS AND METHODS: The adhesives investigated were: AQ Bond (AQB, Sun Medical; Kyoto, Japan), iBond (IBO, Heraeus Kulzer; Hanau, Germany), One-Up Bond F II (OUB, Tokuyama; Tokyo, Japan), and Prompt L-Pop (PLP, 3M/ESPE; Seefeld, Germany). Inhibition layer thickness (ILT) was microscopically measured on 3 disk-shaped specimens each. Shear bond strengths (SBS) on enamel and dentin (n = 8) were determined after 10 min and 24 h water storage of bonded composite specimens (Venus, Heraeus Kulzer). The marginal adaptation of bonded Venus restorations in cylindrical dentin cavities was microscopically evaluated after 10 min of specimen storage (n = 8) in water. The data were statistically analyzed using parametric and nonparametric ANOVA and post-hoc tests at p < 0.05. RESULTS: Adhesive curing under air revealed significant ILT (microm) differences: IBO (4) < AQB (8) < PLP (12) < OUB (23). Upon curing in nitrogen atmosphere, no inhibition occurred with AQB, IBO, and PLP, and < 3 microm for OUB. SBSs on enamel after 10 min or 24 h did not differ according to curing atmospheres (p > 0.05). On dentin, SBSs were higher after curing under N2 (p < 0.05). Irrespective of the curing atmosphere, marginal adaptation was good for AQB and IBO and poor for PLP; OUB revealed significantly smaller gaps under N2 than under air curing. CONCLUSION: Oxygen inhibition of the four self-etching adhesives investigated had no or only moderate effects on bonding efficacy to enamel and dentin.     

Working time of elastomeric impression materials: relevance of rheological tests

PURPOSE: To study possible relationships between rheological parameters of elastomeric impression materials and their dimensional accuracy at different stages during setting within the manufacturers' recommended working time. METHODS: Four chemically different impression material-types were tested. Impressions were taken of a master cone at 30-second intervals after mixing and up to 30 seconds beyond the recommended working time. Impression accuracy (deltad) was determined as the dimensional deviation of stone dies from the master cone. The phase angle delta(t) and storage modulus G'(t) were measured and the working time determined according to ISO 4823. Three operators assessed the latest point in time for uncompromised impression taking. Correlation analysis was performed using Spearman's Rho (P = 0.05). RESULTS: For most materials investigated, deltad(t) was constant within the manufacturers' recommended working time whereas delta(t) and G'(t) changed significantly. There was no correlation (P > 0.05) between deltad(t) versus delta(t) and G'(t), respectively. When determined according to ISO 4823, working time was longer than operator-assessed working time for all materials investigated.     

Negative association of obesity and its related chronic inflammation with serum glycated albumin but not glycated hemoglobin levels

BACKGROUND: Matrix metalloproteinase-8 (MMP-8) has been implicated in the pathogenesis of cardiovascular disease. We evaluated the relative contribution of genetic and non-genetic variables to serum MMP-8 concentrations in nondiabetic subjects without known cardiovascular disease. METHODS: A blood sample was obtained from 100 subjects > or =18 y. Total serum MMP-8 concentrations were assayed by ELISA. MMP8 genotypes (-799 C/T and -381 A/G) were determined by PCR-pyrosequencing. RESULTS: MMP-8 concentrations were significantly higher in subjects with the metabolic syndrome (n=40) compared to those without the metabolic syndrome (11.71 vs 6.81 ng/ml, p<0.001) and in current smokers compared to non-smokers (13.51 vs 7.53 ng/ml, p=0.001). MMP-8 concentrations were significantly correlated with body mass index, triglyceride/HDL ratio, triglycerides, fasting plasma glucose, and age. MMP-8 concentrations were not significantly different between MMP8 genotype groups. In regression analysis, variables that were significantly associated with serum MMP-8 concentrations were presence of the metabolic syndrome and smoking (p<0.001 and p=0.009, respectively), accounting for 21.4% of the variability in serum MMP-8 concentrations. CONCLUSIONS: Our data demonstrate that the metabolic syndrome and smoking are independently associated with elevated serum MMP-8 concentrations. The relationship between MMP-8 concentrations and cardiovascular risk merits further investigation.     

Association of inflammatory biomarkers with long-term outcomes after curative surgery for mass-forming intrahepatic cholangiocarcinoma

Surgery Today - Inflammatory biomarkers such as the neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), and platelet-to-lymphocyte ratio (PLR) are reportedly predictive of the...     

Clinical significance of definite muscle layer in TUR specimen for evaluating progression rate in T1G3 bladder cancer: multicenter retrospective study by the Sapporo Medical University Urologic Oncology Consortium (SUOC)

Purpose

To evaluate the clinical impact on progression and recurrence according to presence and absence of a muscle layer, we conducted a retrospective, multicenter study.

Methods

We retrospectively reviewed 247 patients who received transurethral resection (TUR) of bladder tumors and were pathologically diagnosed as having T1G3 bladder cancer from 1990 to 2009. We ruled out 8 patients who received immediate cystectomy and analyzed the remaining 239 T1G3 patients. Patients who had invasion to the prostatic urethra and patients who underwent a second TUR were not included.

Results

TUR specimens from 194 patients were confirmed to have a definite muscle layer and those from 45 did not. The median follow-up period was 53 months, ranging from 3 to 181 months. The progression-free survival rates at 5 years after TUR were 91.1 % for patients who had a muscle layer in their specimen and 77.3 % for those who did not (p = 0.005, log-rank test). Multivariate analysis indicated that the absence of a muscle layer was a risk factor for progression (p = 0.006, Cox proportional hazards analysis).

Conclusions

Patients without a muscle layer in the specimen had high risk for progression. The initial TUR must have a muscle layer in the specimen. Variations of progression rates in previous studies might be due to different proportions of patients who had a muscle layer in TUR specimens.     

The mutations of the EGFR and K-ras genes in resected stage I lung adenocarcinoma and their clinical significance

Purpose

This study retrospectively assessed the mutations of the epidermal growth factor receptor (EGFR) and K-ras genes and their clinical significance in patients with resected stage I adenocarcinomas.

Methods

A total of 354 patients with resected lung adenocarcinomas were included, and 256 patients with stage I disease were analyzed for the prognostic and predictive value of these mutations.

Results

Mutations of EGFR and K-ras genes were detected in 149 (41.1 %) and 23 (6.4 %) of all tumors, and in 122 (47.6 %) and 14 (5.5 %) of stage I tumors, respectively. There were no significant differences in the disease-free survival (DFS) and overall survival (OS) between the EGFR-mutant and wild-type groups. However, the DFS and OS were significantly shorter in patients with K-ras mutations than in those without (5-year DFS: 50.8 vs. 76.9 %, 5-year OS: 70.0 vs. 86.6 %, p < 0.01). A multivariate analysis showed that K-ras mutations were an independent poor prognostic factor. Twenty-four of the 41 patients with recurrent disease after surgery were treated with an EGFR–TKI. Fifteen EGFR-mutant patients treated with an EGFR–TKI had a better prognosis than did the nine EGFR-wild-type patients.

Conclusion

The presence of an EGFR gene mutation was a predictive factor for the response to EGFR–TKI treatment in patients with resected stage I adenocarcinoma, but was not a prognostic factor. The presence of a K-ras gene mutation was a poor prognostic factor.     

Kinematics of the thoracic spine in trunk lateral bending: in vivo three-dimensional analysis

Background contextIn vivo three-dimensional kinematics of the thoracic spine in trunk lateral bending with an intact rib cage and soft tissues has not been well documented. There is no quantitative data in the literature for lateral bending in consecutive thoracic spinal segments, and there has not been consensus on the patterns of coupled motion with lateral bending.PurposeTo demonstrate segmental ranges of motion (ROMs) in lateral bending and coupled motions of the thoracic spine.Study designIn vivo three-dimensional biomechanics study of the thoracic spine.Patient sampleFifteen healthy male volunteers.Outcome measuresComputed analysis by using voxel-based registration.MethodsParticipants underwent computed tomography of the thoracic spine in three supine positions: neutral, right maximum lateral bending, and left maximum lateral bending. The relative motions of vertebrae were calculated by automatically superimposing an image of vertebrae in a neutral position over images in bending positions, using voxel-based registration. Mean values of lateral bending were compared among the upper (T1–T2 to T3–T4), the middle-upper (T4–T5 to T6–T7), the middle-lower (T7–T8 to T9–T10), and the lower (T10–T11 to T12–L1) parts of the spine.ResultsAt lateral bending, the mean ROM (±standard deviation) of T1 with respect to L1 was 15.6°±6.3° for lateral bending and 6.2°±4.8° for coupled axial rotation in the same direction as lateral bending. The mean lateral bending of each spinal segment with respect to the inferior adjacent vertebra was 1.4°±1.3° at T1–T2, 1.3°±1.2° at T2–T3, 1.4°±1.3° at T3–T4, 0.9°±0.9° at T4–T5, 0.8°±1.0° at T5–T6, 1.1°±1.1° at T6–T7, 1.7°±1.2° at T7–T8, 1.3°±1.2° at T8–T9, 1.6°±0.7° at T9–T10, 1.8°±0.8° at T10–T11, 2.3°±1.0° at T11–T12, and 2.2°±0.8° at T12–L1. The smallest and the largest amounts of lateral bending were observed in the middle-upper and the lower parts, respectively. There was no significant difference in lateral bending between the upper and the middle-lower parts. Coupled axial rotation of each segment was generally observed in the same direction as lateral bending. However, high variability was found at the T2–T3 to T5–T6 segments. Coupled flexion was observed at the upper and middle parts, and coupled extension was observed at the lower part.ConclusionsThis study revealed in vivo three-dimensional motions of consecutive thoracic spinal segments in trunk lateral bending. The thoracolumbar segments significantly contributed to lateral bending. Coupled axial rotation generally occurred in the same direction with lateral bending. However, more variability was observed in the direction of coupled axial rotation at T2–T3 to T5–T6 segments in the supine position. These results are useful for understanding normal kinematics of the thoracic spine.