Double bond conversion of preheated composite resin beneath lithium disilicate standardized occlusal veneers

The purpose of the study was the investigation of the polymerization of a preheated composite resin beneath lithium disilicate. First, lithium disilicate discs in two shades (HT A2 and HT A4) and three different thicknesses (2, 4, and 6 mm) were bonded on dentine with preheated composite resin that was photo-polymerized for 20 s. The composite resin microhardness, the double bond conversion (DC) and their correlation were estimated. Second, standardized occlusal veneers of two shades and two different thicknesses (4 and 6 mm) were bonded with preheated composite resin and photopolymerized for 60 or 270 s. A microhardness line profiling was performed on the cross-section of each specimen and the correspondence DC was calculated. Shade and thickness of lithium disilicate were found to have a significant impact on micro-hardness and DC of the composite resin. Beneath standardized occlusal veneers DC can reach clinically acceptable level if photopolymerization duration is extended properly.

The effect of universal adhesives on dentine collagen

OBJECTIVES

The purpose of the study was to evaluate the integrity of dentine type I collagen after self-etching (SE) treatments with strong and mild universal adhesives.

METHODS

Coronal dentine specimens (n=10/product) were imaged by optical microscopy and analyzed by ATR-FTIR spectroscopy before and after treatment with 32% phosphoric acid gel (PA-negative control), 17% neutral EDTA (ED-positive control) conditioners and Adhese Universal (AD), Clearfil Universal Bond Quick (CQ), G-Premio Bond (GP), Prelude One (PR) and Scotchbond Universal (SB) adhesives. From the spectroscopic analysis the following parameters were determined: a) Extent of dentine demineralization (DM%) and b) percentage area of the Amide I curve-fitted components of β-turns, 3₁₀-helix/β-turns, α-helix, random coils, β-sheets and collagen maturation (R) index. Statistical analysis was performed by one-way ANOVA (DM%), paired t-test/Wilcoxon test (Amide I components) and Spearman correlation coefficient (DM% vs Amide I components) at an a=0.05 level.

RESULTS

PA, ED and GP removed the smear-layer and opened tubule orifices, whereas all other treatments removed only the intratubular smear-layer fraction. The ranking of the statistically significant differences in DM% was PA>GP>ED>AD, SB, CQ, PR, with AD being significantly different from PR. Regarding the Amide I components, PA demonstrated a significant reduction in β-turns, α-helices and an increase in β-sheets, GP a reduction in β-turns, AD an increase in β-turns and random coils, and CQ an increase in β-turns. PR, SB and ED showed insignificant differences in all the Amide I components. Significant correlations were found between DM%-random coils and DM%-R.

SIGNIFICANCE

The universal adhesives used in the SE mode induced none to minimal changes in dentine collagen structure, without evidence of the destabilization pattern observed after conventional phosphoric acid treatments.

Nutrition education in medical schools (NEMS) project: Joining ESPEN and university point of view

BACKGROUND & AIMS

Nutrition education is not well represented in the medical curriculum. The aim of this original paper was to describe the Nutrition Education in Medical Schools (NEMS) Project of the European Society for Clinical Nutrition and Metabolism (ESPEN).

METHODS

On 19 January 2020, a meeting was held on this topic that was attended by 51 delegates (27 council members) from 34 countries, and 13 European University representatives.

RESULTS

This article includes the contents of the meeting that concluded with the signing of the Manifesto for the Implementation of Nutrition Education in the Undergraduate Medical Curriculum.

CONCLUSION

The meeting represented a significant step forward, moved towards implementation of nutrition education in medical education in general and in clinical practice in particular, in compliance with the aims of the ESPEN Nutrition Education Study Group (NESG).

Bonding of Composite to Base Materials: Effects of Adhesive Treatments on Base Surface Properties and Bond Strength

PURPOSE

To evaluate the effects on the surface properties (morphology, roughness, microhardness, composition) and bond strength to composite of four types of base cements (Equia-Fil/EQF, Angelus white MTA/MTA, Biodentin/BDN and IRM/IRM) when treated with phosphoric acid etching (PAE) or two self-etch adhesives (Select One Prime & Bond and Clearfil S3 Bond).

MATERIALS AND METHODS

Disk-shaped specimens were prepared and stored until complete setting. The surfaces before and after treatments were examined by stereomicroscopy, optical profilometry, ATR-FTIR, and LV-SEM/EDX. Interfacial bond strength with composite was evaluated under shear loading (SBS) using a conventional bonding resin (Heliobond) on silane treated (SIL) specimens as a reference. Failure mode was evaluated using stereomicroscopy.

RESULTS

PAE induced compositional changes on MTA and BDN, forming a phosphate-rich surface layer, probably composed of Ca-P salts. Dissolution of the amorphous cement fractions was evident in all materials. SPB and CSB did not show remarkable changes apart from an increase in Si content on MTA. On all bases, PAE resulted in the highest values for most of the roughness parameters. SPB and CSB showed lower or equal average roughness (Sa) and percentage of additional surface area contributed by the texture (Sdr) compared to the control in MTA and EQL. In terms of SBS, the highest β (Weibull shape parameter) in MPa were MTA-SIL = 5.79, BDN-PAE = 3.67, and MTA-PAE = 3.46, whereas the highest α (Weibull scale parameter) were EQF-CSB = 9.08, BDN-PAE = 5.13, and BDN-SIL = 4.67. Adhesive failures with less than 20% of the bonding area were encountered in IRM-PAE and SIL, EQF-CBS and MTA-SIL.

CONCLUSION

Each base material requires a different procedure for optimal bonding with composite. Phosphoric acid etching and application of the conventional bonding resin Heliobond is the preferred procedure for composite bonding to MTA, BDN, IRM, but for composite bonding to CSB for EQF, the mild self-etch adhesive is preferable.

Modular minimally invasive extracorporeal circulation systems; can they become the standard practice for performing cardiac surgery?

Minimally invasive extracorporeal circulation (MiECC) has been developed in an attempt to integrate all advances in cardiopulmonary bypass technology in one closed circuit that shows improved biocompatibility and minimizes the systemic detrimental effects of CPB. Despite well-evidenced clinical advantages, penetration of MiECC technology into clinical practice is hampered by concerns raised by perfusionists and surgeons regarding air handling together with blood and volume management during CPB. We designed a modular MiECC circuit, bearing an accessory circuit for immediate transition to an open system that can be used in every adult cardiac surgical procedure, offering enhanced safety features. We challenged this modular circuit in a series of 50 consecutive patients. Our results showed that the modular AHEPA circuit design offers 100% technical success rate in a cohort of random, high-risk patients who underwent complex procedures, including reoperation and valve and aortic surgery, together with emergency cases. This pilot study applies to the real world and prompts for further evaluation of modular MiECC systems through multicentre trials.

Minimal extracorporeal circulation reduces the incidence of postoperative major adverse events after elective coronary artery bypass grafting in high-risk patients. A single-institutional prospective randomized study

Coronary artery bypass grafting (CABG) using minimal extracorporeal circulation (MECC) has been associated with an improved short-term clinical outcome compared to conventional extracorporeal circulation (CECC). The aim of this study was to evaluate the impact of MECC compared to CECC on postoperative major adverse events in high-risk patients undergoing elective coronary revascularization procedures. Two hundred patients undergoing elective CABG were randomized into two groups. In Group A (n=100), MECC was used while Group B (n=100) included patients who were operated on CECC. The incidence of postoperative major adverse events (myocardial infarction, renal failure, stroke, death) was the primary end-point of the study. MECC was associated with a 77% relative risk reduction in the incidence of major adverse events compared to CECC (p=0.004). The rate of major adverse events occurring in the high-risk patient subgroup (preoperative left ventricular ejection fraction ≤40%, age >65 years, EuroSCORE II >5) operated on with MECC was significantly lower in comparison to their CECC counterparts. Based on our results, cardiac centres should be encouraged to use MECC as the standard circuit when performing elective coronary procedures, even in a high-risk population.

Intramyocardial implantation of autologous bone marrow-derived stem cells combined with coronary artery bypass grafting in patients with ischemic cardiomyopathy: a pilot study

BACKGROUND

Ischemic cardiomyopathy has the distinctiveness of irreversible myocardial damage with scar tissue formation and mainly impaired perfusion of the remaining viable myocardium. We present results of the first series of patients with severe ischemic cardiomyopathy managed in our institution with intramyocardial implantation of autologous bone marrow stem cells at the time of coronary artery bypass grafting. The aim is to evaluate feasibility and safety of the procedure in our institution.

PATIENTS AND METHODS

Nine patients with severe ischemic cardiomyopathy scheduled for elective coronary artery bypass grafting were managed with concurrent intramyocardial autologous bone marrow stem cells injection in pre-defined viable peri-infarct areas that showed poor perfusion and could not be grafted. Detailed mapping of infracted and hibernating myocardial segments was performed in all patients with single photon emission computed tomography segmental analysis.

RESULTS

There was no perioperative 30-day mortality. Improvement was evident in left ventricular ejection fraction which was increased significantly from 31.3% preoperatively to 42.4%, 46.6% and 52.5% at 3, 6 and 12 months respectively. Postoperative thallium scintigraphy revealed increased perfusion in myocardial segments corresponding to areas of stem cell injection and a net reduction in the estimated infarct size at 6 and 12 months in 5/8 (62.5%) patients.

CONCLUSIONS

Preliminary data from this pilot study show that intramyocardial administration of bone marrow stem cells in patients undergoing coronary bypass grafting for ischemic cardiomyopathy is safe and associated with an improvement in left ventricular function and enhanced reperfusion of non-viable myocardial territories.

One stage carotid artery stenting and open heart surgery: a novel approach

AIM

The optimal management of the patients requiring cardiac surgery with simultaneous severe carotid disease remains controversial. The traditional approach involves staged or combined carotid endarterectomy and cardiac surgery. This study evaluated the feasibility and safety of angioplasty and stenting for the treatment of carotid stenoses combined with cardiac operations in order to reduce the risk of perioperative stroke.

METHODS

In a prospective, non-randomized study, we analyzed 70 consecutive patients requiring cardiac surgery with simultaneous severe carotid artery disease that underwent carotid artery stenting (CAS) and cardiac surgery in one stage. Symptomatic patients with ≥ 60% carotid stenosis, and asymptomatic patients with ≥ 70% stenosis, were treated using CAS under local anesthesia immediately before the open heart surgery. Cerebral protection devices were used in all cases.

RESULTS

Despite the high baseline risk profile, our results were very encouraging. Carotid stenting was successful in all patients. No neurological complications occurred during the carotid stenting procedures. The 30-day death/stroke rate was 1.4% (no deaths, 1 contralateral minor stroke). No myocardial infarctions occurred. The carotid restenosis rate was zero during the long-term follow up.

CONCLUSION

The low complication rate suggests that CAS and cardiac surgery in one stage offers a safer therapeutic option compared to combined carotid endarterectomy and cardiac surgery. It may also be safer than with the staged CAS and coronary artery bypass grafting approach as well.

Traumatic innominate artery transection

Blunt innominate artery injury is a rare but often lethal complication of severe deceleration trauma. We report the case of a 38-year-old man with such an injury who was successfully operated on an emergency basis. In cases of brachiocephalic vessel trauma, a high index of suspicion in chest deceleration injuries may lead to a proper investigative process and an accurate diagnosis. Clinical signs as blood pressure gradient between the arms and widening of the mediastinum on chest X-ray is highly suggestive of trauma of the thoracic aorta and its great vessels. A chest CT scan may contribute to the diagnosis and can rule out major trauma of the aorta, but the procedure of choice for the definite diagnosis is usually the angiography. Subsequent early repair is favorable to avoid complications and fatal events. Cardiopulmonary bypass use in selected cases favors the outcome.