Effect of modulated photoactivation of bulkfill composite on microleakage in fluorosed and nonfluorosed teeth: A confocal laser scanning microscopy study

Aim:

The aim of this study is to compare the microleakage of bulkfill composite activated by modulated photoactivation between fluorosed and nonfluorosed teeth using the confocal laser scanning microscope.

Methodology:

One hundred and twenty intact human premolar teeth with Thylstrup and Fejerskov index fluorosis index 0–4 were stored in 0.5% thymol at the room temperature until further use. Standardized Class V preparations of 2 mm depth, 3 mm width, and 2 mm height were prepared on the buccal surface. The cavities were etched with 37% phosphoric acid, rinsed and primed with Tetric N bond, cured for 20 s with Quartz Tungsten Halogen (QTH) variable intensity light-curing unit spectrum-800 operating at 450 mW/cm². Later, bulk fill composite was placed in the cavity and cured. Depending on the curing mode used, all the fluorosed and nonfluorosed teeth were divided into three subgroups each (n = 20) – Conventional light curing, stepped curing, and pulse delayed curing. All samples were stored in distilled water at the room temperature for 24 h and subjected to 500 thermocycles. The prepared teeth were placed in 0.6% rhodamine solution for 48 h; sectioned longitudinally using a hard-tissue microtome and scanned under a confocal laser scanning electron microscope. Data were analyzed using the one-way ANNOVA, Wilcoxson signed-rank test, and Kruskal–Wallis test.

Results:

Significant differences were observed between fluorosed and nonfluorosed groups. Intragroup comparisons showed significant differences between fluorosed step and conventional subgroups.

Conclusion:

Fluorosed teeth had higher microleakage values than nonfluorosed teeth. Pulse-delayed subgroup had the least microleakage to that of conventional and stepped curing subgroups, in both fluorosed and nonfluorosed groups.

Long term survival in high-risk patients after percutaneous mitral leaflet repair in a single centre: comparable mortality regardless of aetiology

Background

Percutaneous mitral leaflet repair (PMVR) is a safe and effective alternative to conventional surgery in high-risk patients with both degenerative (DMR) and functional (FMR) mitral regurgitation. We present an analysis of a large cohort of consecutive patients treated with PMVR at a high-volume UK centre.

Purpose

We sought to analyse the outcomes of a group of patients undergoing PMVR over a 7-year period at a single centre, where surgery had been excluded. We hypothesised that the long-term mortality in this group would be high and would differ depending on the aetiology of MR.

Methods

We identified 246 consecutive patients over the duration of the PMVR programme, where follow up and pre-procedural data were available. We collected baseline characteristics including age at procedure, left ventricular ejection fraction (LVEF), left ventricular indexed diastolic volumes (LVEDVi) and aetiology of MR. Post procedural data included MR at end of procedure, all-cause mortality and duration of follow up.

Results

Baseline characteristics for the group, as a whole, were as follows: mean age 76±11 years, 170 (69%) male, DMR 136 (55%) vs. FMR 110 (45%), LVEF 49±15%. Baseline data by aetiology subgroup: mean age DMR 80±9 vs. FMR 71±11 (p<0.001), LVEF DMR 58±10 vs. FMR 40±14 (p<0.001), LVEDVi DMR 71±25 FMR 85±25 (p<0.001). 99% of patients were treated with the MitraClip® device (Abbott, US), 1% received the Pascal device (Edwards, US). Post-procedural MR grade was similar for both groups (DMR 1.5±0.8 vs. 1.4±0.8, p=NS). Overall procedural mortality was 0.4% and at a mean follow up of 1097 days (median 1021, IQR 289–1555) was 30.8%. Mortality was identical regardless of aetiology (DMR 30.9% vs. FMR 30.8%, p=NS).

Conclusions

This analysis of consecutive “real world” patients demonstrates encouraging survival outcome at a mean of 3 years after PMVR, regardless of MR aetiology. DMR patients tended to be older but with lower LVEDVi and significantly higher LVEF. These data compare favourably with the published literature, where mortality for mixed and similarly high-risk populations at 12 months averages approximately 20–25%. Mortality in our FMR group at 3 years was also similar to that seen in the recently published COAPT study at 2 years. We have demonstrated that PMVR is a safe option for our cohort of unselected high-risk patients presenting with either degenerative or functional MR. We hypothesise that the absence of survival difference could relate to the younger age of FMR patients despite the significantly lower baseline LVEF and higher ventricular volumes. This analysis encourages the more routine use of PMVR for FMR in the UK, where currently only DMR is commissioned.

Funding Acknowledgement

Type of funding source: None

Intraprocedural mean mitral pressure gradient predicts mortality in percutaneous edge-to-edge mitral repair for functional mitral regurgitation

Introduction

Percutaneous edge-to-edge mitral repair is a safe treatment method for functional (FMR) and degenerative (DMR) mitral regurgitation. Iatrogenic mitral stenosis remains a concern and periprocedural transoesophageal echocardiography is essential for real-time monitoring of mean mitral pressure gradient (intra-MMPG) and to guide clip deployment.

Purpose

Published data suggests intra-MMPG predicts clinical outcome and mortality only in DMR patients. We sought to validate these findings in a large high-volume UK center cohort with prolonged follow-up and further explore its use to predict mortality in functional MR patients.

Methods

All consecutive patients who underwent edge-to-edge mitral repair between 2010 and 2020 were analysed. The intra-MMPG and the severity of MR grade from the transoesophageal echocardiogram post-clip deployment (intra-MRgrade) were collected. Statistical analysis using covariates before and after edge-to-edge repair were compared using paired tests and cox regression models were used to assess the relationship of covariates with all-cause mortality. p<0.05 was deemed as statistically significant.

Results

We analysed data from 246 consecutive patients, 65% were men and mean age was 76±11 years. Pre-procedure LVEF was 49±15%, TAPSE was 16±6 mm, severity of MR was 3.8±0.5, 80% had NYHA III/IV and 45% had FMR. Post procedure, there was a significant reduction in severity of MR grade (3.8±0.5 to 1.7±0.8; p<0.001) and a reduction in LVEF (49±15 to 45±15%; p<0.001). There were significant improvements in NYHA class (3.2±0.6 to 2.0±0.6; P<0.0001) and LV outflow tract VTI (15±5 to 17±4 cm; p<0.001).

Patients were followed-up for a median of 1021 days (inter-quartile range 289 to 1555) during which 76 patients died. Multivariate survival analysis (see table) showed that the increase in intra-MMPG was independently associated with mortality for FMR, but not for DMR. Furthermore, higher intra-MRgrade was associated with mortality for FMR patients only.

Conclusion

Intraprocedural mean mitral pressure gradient (intra-MMPG) predicts mortality in percutaneous mitral edge-to-edge repair for FMR, but not for DMR, herby challenging previously published data.

Funding Acknowledgement

Type of funding source: None

Inhibition of plant pathogenic fungi by endophytic Trichoderma spp. through mycoparasitism and volatile organic compounds

Antagonism of plant pathogenic fungi by endophytic fungi is a well-known phenomenon. In plate assays, the antagonism could be due to mycoparasitism, competition for space or antibiosis, involving a chemical diffusate, or a volatile organic compound (VOC). In this study, we demonstrate that besides mycoparasitism, VOCs play a major role in antagonism of pathogenic fungi by four endophytic fungi belonging to the genus Trichoderma. Using a double-plate assay, we show that all the four endophytic Trichoderma species significantly inhibited mycelial growth of three of the four pathogens, (Sclerotinia sclerotiorum-TSS, Sclerotium rolfsii-CSR and Fusarium oxysporum-CFO), while that of Macrophomina phaseolina-CMP was not affected. GC-MS analysis of the pure cultures of one of the endophytic fungi studied, namely, Trichoderma longibrachiatum strain 2 (Acc. No. MK751758) and the pathogens, F. oxysporum-CFO and M. phaseolina-CMP revealed the presence of several VOCs including hydrocarbons, alcohols, ketones, aldehydes, esters, acids, ethers and different classes of terpenes. In mixed double plates, where the endophyte was grown along with either of the two plant pathogens, F. oxysporum-CFO or M. phaseolina-CMP, there was an induction of a number of new VOCs that were not detected in the pure cultures of either the endophyte or the pathogens. Several of these new VOCs are reported to possess antifungal and cytotoxic activity. We discuss these results and highlight the importance of such interactions in endophyte-pathogen interactions.