Effect of a Diode Laser (445 nm) on Polymerization Efficiency of a Preheated Resin Composite Used for Luting of Indirect Composite Restorations

PURPOSE

The aim of this study was to evaluate the polymerization efficiency of a preheated resin composite used as a luting agent for indirect restorations light-cured by a blue diode laser (445 nm).

METHODS

Bronze molds were used to prepare cylindrical specimens of a laboratory composite (Ceramage) with dimensions 2, 3, and 4 mm in height and 8 mm in diameter. The molds had additional height of 120 μm for the placement of the preheated resin composite. A nanohybrid resin composite (Enamel Plus HRi) was preheated at 55°C to use as a luting agent. Photopolymerization was followed for 20 seconds using three light sources: a diode laser emitting at 445 nm (SiroLaser Blue) and two light-emitting diode (LED) units (Bluephase Style and Valo). Degree of conversion (DC) of the preheated resin composite was evaluated using Fourier transform infrared spectroscopy.

RESULTS

The results indicated that the main effects of the analysis were significant for both material thickness (p<0.001) and polymerization method (p<0.001). The preheated resin composite was not polymerized under 4-mm-thick specimens, independent of the light-curing unit. For 2-mm material thickness, there was no difference among the three light-curing units (p=0.383), while 3-mm Bluephase Style presented very low DC.

CONCLUSIONS

Diode laser (445 nm) achieved better polymerization efficiency at the same fluence compared to the LED unit at 3-mm depth, implying a better mechanical behavior and potential improved adhesion of the luting material to dentin.

Influence of novel risk markers on defibrillator implantation in hypertrophic cardiomyopathy

Background/Introduction

To guide implantable defibrillator (ICD) use in hypertrophic cardiomyopathy (HCM), European Society of Cardiology (ESC) guidelines recommend using individualised sudden death (SCD) risk scores based on quantitative clinical data. Newly published American guidelines are based on the accumulation of binary risk markers, which include imaging-based novel risk markers (NRMs) that were absent from the development of the ESC's algorithm. These NRMs are ejection fraction &lt;50%, apical aneurysm, and extensive late gadolinium enhancement on cardiac magnetic resonance (CMR) imaging.

Purpose

To assess how NRMs may have altered ICD prescription across ESC-based SCD risk status prior to publication of current American guidance.

Methods

We examined electronic records (2013–2020) of a subset of HCM patients with contemporaneous (within 12 months) CMR and echocardiography data for NRMs, ESC risk status, and ICD prescription. Differences in categorical data were assessed by Fisher's exact test.

Results

We studied 334 HCM patients (74% male; age: 58±14 years), of whom 83 (25%) were referred for ICD. ESC risk status was considered low, medium (4–6% 5-year SCD risk), or high in 264, 26, and 20 patients, for whom ICDs were recommended in 40 (15%), 20 (77%), and 18 (90%) patients, respectively. In patients with low SCD risk status, rate of ICD recommendation was significantly higher when ≥1 NRMs were present (34/126 – 27% vs. 0 NRMs: 6/138 – 4%; p&lt;0.0001). NRMs did not appear to influence ICD recommendation in patients with medium (≥1 NRMs: 14/17 – 82% vs. 0 NRMs: 6/9 – 67%; p=0.6) or high (≥1 NRMs: 14/15 – 93% vs. 0 NRMs: 4/5 – 80%; p=0.4) SCD risk status (Figure 1). NRMs were less frequent in low risk patients than in high risk patients (126/264 – 48% vs. 15/20 – 75%; p&lt;0.05), suggesting interaction between ESC status and NRMs (Figure 2).

Conclusion

NRMs have disproportionate influence on ICD prescription in low ESC risk HCM patients. However, NRMs are not independent of ESC risk status, suggesting iterative development of the ESC's algorithmic approach will be the most effective way of predicting SCD.

Funding Acknowledgement

Type of funding sources: None.

Heart rate recovery and risk of cardiovascular disease and all-cause mortality: a systematic review of prospective cohort studies

Funding Acknowledgements

Type of funding sources: None.

Purpose

An attenuated decrease of heart rate recovery (HRR) immediately after exercise is an indicator of autonomic dysfunction and has been linked with a higher risk of cardiovascular disease and all-cause mortality in both healthy and clinical population. However, the evidence regarding its potential prognostic value varies across studies making its implementation in clinical practice for risk assessment difficult. The purpose of the present systematic review is therefore, to investigate the predictive value of heart rate recovery in CVD disease and all-cause mortality, in an evidenced-based manner to encourage its incorporation in clinical practice

Methods and Results

A systematic review was performed through a comprehensive search on PubMed that focused only on prospective cohort studies. Of the studies retrieved, a total of 13 eligible articles were included in this systematic review with nine of them enrolling 37 457 participants and 709 CVD cases for cardiovascular events, and 12 comprising 45 905 participants and 4 301 deaths for all-cause mortality.The study quality of the included studies was rated moderate to high (4-8) with high heterogeneity (I² = 0.0001). Results revealed no statistically significant difference in HRR for patients with and without cardiovascular events M=-2672.16, at 95% CI [-7341.6,1997.32] ; P-value = .234 as well as for people who died and those who did not M= -3141.667, at 95% CI [-7627.448,1344.144], P-value = .151. Also, the association between CVD and mortality was presented statistically significant, Chi-Square = p&lt;0.0001 while a further analyses of heart rate recovery revealed that when distinguished between low and high, it was found to have a strong positive association with all-cause mortality, Chi-Square = p&lt;0.0001.

Conclusion

The current systematic review findings indicated that a low HRR is directly linked with greater all-cause mortality risk. Also, given the strong association found between CVD and mortality, the study further supported that even though indirectly, a low HRR is also associated with an increased risk of cardiovascular events, supporting the notion that HRR has a prognostic value and could be used in clinical practice.

Analysis of genome-wide DNA arrays reveals the genomic population structure and diversity in autochthonous Greek goat breeds

Goats play an important role in the livestock sector in Greece. The national herd consists mainly of two indigenous breeds, the Eghoria and Skopelos. Here, we report the population structure and genomic profiles of these two native goat breeds using Illumina’s Goat SNP50 BeadChip. Moreover, we present a panel of candidate markers acquired using different genetic models for breed discrimination. Quality control on the initial dataset resulted in 48,841 SNPs kept for downstream analysis. Principal component and admixture analyses were applied to assess population structure. The rate of inbreeding within breed was evaluated based on the distribution of runs of homozygosity in the genome and respective coefficients, the genomic relationship matrix, the patterns of linkage disequilibrium, and the historic effective population size. Results showed that both breeds exhibit high levels of genetic diversity. Level of inbreeding between the two breeds estimated by the Wright’s fixation index F_ST was low (Fst = 0.04362), indicating the existence of a weak genetic differentiation between them. In addition, grouping of farms according to their geographical locations was observed. This study presents for the first time a genome-based analysis on the genetic structure of the two indigenous Greek goat breeds and identifies markers that can be potentially exploited in future selective breeding programs for traceability purposes, targeted genetic improvement schemes and conservation strategies.

A multi-farm assessment of Greek black pig genetic diversity using microsatellite molecular markers

Local breeds are important for the maintenance of genetic diversity and future food security. Nowadays, the worldwide distribution of pigs is dominated by a few breeds, tending towards a severe loss of pig biodiversity. Thus, it is critical to maintain distinct populations of pig breeds. The Greek black pig, a breed raised locally and known for the high quality of its meat for cured products, is the only traditional indigenous pig breed reared in Greece. We investigated the genetic diversity, based on microsatellite analysis, of the Greek black pig and evaluated its genetic uniqueness. One hundred and three pigs from 12 Greek farms were analyzed using 11 microsatellites. The total number of alleles amounted to 135, with a mean number of alleles per locus of 12.27, ranging between 10 and 16 alleles. The observed heterozygosity ranged from 0.363 to 0.825 per locus. The expected heterozygosity ranged from 0.471 to 0.707. The inbreeding coefficient ranged from -0.329 to 0.229. We conclude that the Greek black pig, despite its low population size, has a high degree of genetic variability, which will be useful for breeding programs aimed at maintaining long-term survival of this ancient breed.