Elution from direct composites for provisional restorations

Purpose To assess elution from direct composite materials for provisional restorations and compare them with elution from direct restorative composites for permanent restorations.Methods Two dual-cure (Integrity Multi-Cure and Tempsmart DC) and two self-curing composites (Protemp 4 and Structur 3) were used, with Essentia serving as a reference. Cylindrical specimens (n=20) were cured according to the manufacturer's instructions; the dual-cure materials were prepared in both self- and dual-curing modes. Elution experiments were performed using water and absolute ethanol. The samples were incubated at 37 °C for either 24 h or four weeks; the extraction solvents were refreshed weekly. The eluted BisEMA (-3 / -6 / -10), BisGMA, CQ, UDMA, and TEGDMA were quantified using UHPLC-MS/MS.Results Monomer elution was detected in all provisional composites at 24 h and four weeks, but the amounts released did not exceed those released by the reference composite. When prepared in self-curing mode, Integrity Multi-Cure exhibited significantly higher elution of BisEMA-3, -6, and -10 in ethanol both after 24 h and cumulatively after four weeks. Self-cured Tempsmart DC released significantly more CQ, TEGDMA, and UDMA in both water and ethanol after immersion for 24 h and four weeks, along with significantly more BisGMA in ethanol both after 24 h and four weeks comparison to dual-cured Tempsmart DC (two-way ANOVA, post-hoc Tukey, P < 0.05).Conclusions Provisional composite materials did not elute higher amounts of monomers than a restorative composite. Dual-cured materials, prepared in the self-curing mode, show a trend towards higher monomer elution.

Shear bond strength of orthodontic brackets to specimens fabricated from temporary restorative materials by 3D-printing, CAD/CAM technology, and the conventional technique after surface treatment by sandblasting and laser

OBJECTIVES

This study assessed the shear bond strength (SBS) of stainless steel (SS) orthodontic brackets to specimens fabricated from polymethyl methacrylate (PMMA) temporary restorative material by 3D-printing, computer-aided design/computer-aided manufacturing (CAD/CAM) technology, and the conventional technique, after surface treatment by sandblasting and laser.

MATERIAL AND METHODS

In this in vitro study, 60 disc-shaped specimens with 8mm diameter and 1mm height were fabricated from PMMA temporary restorative material by 3D-printing, CAD/CAM, and the conventional technique. In each group (n=20), half of the specimens were sandblasted while the other half underwent Er,Cr:YSGG laser irradiation. Brackets were bonded to the specimens and underwent thermocycling followed by SBS testing. Data were analysed by one-way ANOVA, independent t-test, and LSD test (alpha=0.05).

RESULTS

A significant difference existed among the three fabrication methods in SBS in both laser (P<0.001) and sandblasting (P<0.001) surface treatment groups. In laser group, the mean SBS of CAD/CAM (P=0.000) and conventional (P=0.000) groups was significantly lower than that of 3D-printing group. In sandblasting group, the SBS of CAD/CAM group was significantly lower than 3D-printing (P=0.000) and conventional (P=0.000) groups. The mean SBS of laser-treated specimens was significantly higher than sandblasted specimens in 3D-printing group (P=0.000), and significantly lower than sandblasted specimens in the conventional group (P=0.000). A significantly higher SBS was obtained by laser treatment compared with sandblasting irrespective of the fabrication method (P=0.000).

CONCLUSION

The highest SBS of SS orthodontic brackets to temporary restorative material was recorded for 3D-printed specimens treated by Er,Cr:YSGG laser irradiation.

In vitro fatigue and fracture testing of temporary materials from different manufacturing processes in implant-supported anterior crowns

OBJECTIVES

The aim of this study was to investigate the in vitro fatigue and fracture force of temporary implant-supported anterior crowns made of different materials with different abutment total occlusal convergence (TOC), with/without a screw channel, and with different types of fabrication.

MATERIALS AND METHODS

One hundred ninety-two implant-supported crowns were manufactured (4° or 8° TOC; with/without screw channel) form 6 materials (n = 8; 2 × additive, 3 × subtractive, 1 × automix; reference). Crowns were temporarily cemented, screw channels were closed (polytetrafluoroethylene, resin composite), and crowns were stored in water (37 °C; 10 days) before thermal cycling and mechanical loading (TCML). Fracture force was determined.

STATISTICS

Kolmogorov-Smirnov, ANOVA; Bonferroni; Kaplan-Meier; log-rank; α = 0.05.

RESULTS

Failure during TCML varied between 0 failures and total failure. Mean survival was between 1.8 × 105 and 4.8 × 105 cycles. The highest impact on survival presented the material (η2 = 0.072, p < .001). Fracture forces varied between 265.7 and 628.6 N. The highest impact on force was found for the material (η2 = 0.084, p < .001).

CONCLUSION

Additively and subtractively manufactured crowns provided similar or higher survival rates and fracture forces compared to automix crowns. The choice of material is decisive for the survival and fracture force. The fabrication is not crucial. A smaller TOC led to higher fracture force. Manually inserted screw channels had negative effects on fatigue testing.

CLINICAL RELEVANCE

The highest stability has been shown for crowns with a low TOC, which are manufactured additively and subtractively. In automix-fabricated crowns, manually inserted screw channels have negative effects.

The "Trick" Knot-A Modified Technique of the Removable "Shoelace" Knot for Temporary Ligation of the Uterine Artery at Its Origin

STUDY OBJECTIVE

To demonstrate the "trick" knot, a technique of temporary ligation of the uterine artery at origin, a modification of the previously published "shoelace" knot.

DESIGN

A video demonstration.

SETTING

A private hospital.

INTERVENTION

Bilateral uterine arteries at origin are exposed after dissection of the peritoneum over the triangle formed by the round ligament, the infundibulopelvic ligament, and the pelvic sidewall [Video 1]. A 60-cm long free polyglactin absorbable suture with preformed knots at each end is introduced around the skeletonized uterine artery. Using a single throw, the "trick" knot is made by pulling out a loop of thread. The end is cut short, and the same suture is used to similarly ligate the other uterine artery. Each knot thus formed has a free end and a knotted end. Laparoscopic myomectomy is performed. On completion of the procedure, the knot is released by pulling the free end, restoring the blood supply to the uterus.

CONCLUSION

Bilateral uterine artery ligation, although an effective method to curb bleeding during a laparoscopic myomectomy, when performed permanently, may lead to undesirable outcomes in women who wish to preserve fertility [1-3]. Methods for temporary ligation of the uterine artery at origin, such the removable vascular clips, are thus regarded justifiable [4]. In contrast to the removable "shoelace" knot, which uses a loop to make a throw, the technique of performing the "trick" knot mimics the steps of forming a regular intracorporeal knot [5]. This makes the latter technically easier and hence faster to perform, while still being as economic and reproducible as the former.

Setting up a temporary isolation tent site for asymptomatic COVID-19 positive male migrant workers in Qatar

BACKGROUND

Qatar has a unique demographic composition, involving hundreds of thousands of male blue-collar workers living in places where physical distancing measures are difficult to implement. This study aimed to describe the rapid development and operations of a temporary isolation facility, which was composed of tents, for asymptomatic COVID-19 positive migrant workers.

DESIGN

The government established several temporary isolation facilities to house this important group of the community. This was achieved through daily meetings over a short period, thanks to the collaboration of government and private partners, in parallel to the facility being built and required resources procured.

RESULTS

A 3,726-patient capacity isolation facility composed of large tents was constructed in 1 month and was kept operational from April 16 to June 20, 2020. Over that period, it received a total of 18,900 patients. It took 10 days from the decision to set up the first part of the isolation facility to admitting its first occupants.

CONCLUSIONS

The COVID-19 pandemic necessitated the implementation of unprecedented global public health and physical distancing measures to contain the spread of the virus among the population. Rapidly opening a temporary COVID-19 isolation facility bought the healthcare sector time to set up more permanent solutions to contain the spread of the virus.

Cytocompatibility of 3D printed dental materials for temporary restorations on fibroblasts

Background

Three-dimensional (3D) printing is widely used in the fabrication of dental prostheses; however, the influence of dental materials used for 3D printing on temporary restoration of fibroblasts in tissues is unclear. Thus, the influence of different dental materials on fibroblasts were investigated.

Methods

Digital light processing (DLP) type 3D printing was used. Specimens in the control group were fabricated by mixing liquid and powder self-curing resin restoration materials. The temporary resin materials used were Model, Castable, Clear-SG, Tray, and Temporary, and the self-curing resin materials used were Lang dental, Alike, Milky blue, TOKVSO CUREFAST, and UniFast III. Fibroblast cells were cultured on each specimen and subsequently post-treated for analysis. Morphology of the adhered cells were observed using a confocal laser scanning microscope (CLSM) and a scanning electron microscope (SEM).

Results

CLSM and SEM cell imaging revealed that the 3D printed material group presented better cell adhesion with well-distributed filopodia compared to that in the conventional resin material group. Cell proliferation was significantly higher in the 3D printing materials.

Conclusion

Superior cytocompatibility of the specimens fabricated through 3D printing and polishing process was demonstrated with the proof of better cell adhesion and higher cell proliferation.

Internal Carotid Artery Test Balloon Occlusion Using Single Photon Emission Computed Tomography Scan in the Management of Complex Cerebral Aneurysms and Skull Base Tumors: A 20-Year Review

BACKGROUND

Test balloon occlusion (TBO) is important in the management of complex cerebrovascular and skull base lesions when permanent occlusion (PO) of a parent artery may be indicated. Several adjuncts may be used to increase the sensitivity of TBO to predict whether PO will be tolerated. This is an observational study to evaluate the utility of internal carotid artery (ICA) TBO using single photon emission computed tomography (SPECT) scan in the management of complex vascular pathology and skull base tumors.

METHODS

All TBO procedures performed over a 20-year period were analyzed. Clinical assessment and angiographic collateral flow were combined with semi-quantitative cerebral blood flow analysis using ^99mTc hexamethylpropylene-amine oxime SPECT scan during ICA TBO. Evaluation of collateral circulation after TBO, and the complications of TBO and the safety of PO after successful TBO were evaluated.

RESULTS

Eighty-three patients underwent TBO without complication. Of 45 patients with satisfactory TBO, 28 proceeded to PO. Three patients developed transient ischemic symptoms thought to be embolic in origin. Thirty-eight patients had unsatisfactory TBO, of whom 15 required PO accompanied by a bypass procedure. Forty patients in the series did not undergo permanent vessel occlusion.

CONCLUSIONS

SPECT scan-enhanced TBO is an important component of the management of complex vascular pathology and skull base tumors, permitting safe PO of the parent vessel and definitive treatment of the main pathology.

"Temporary" Short Segment Fixation in Treating Adolescent Lumbar Spondylolysis

BACKGROUND

We have introduced a new operation for isthmic spondylolysis in adolescents and evaluated its clinical efficacy.

METHODS

A total of 30 adolescent patients with isthmic spondylolysis and chronic low back pain underwent "temporary" short-segmental pedicle screw combined with transverse device fixation and isthmic bone graft repair treatment. Radiograph and computed tomography images were evaluated during regular follow-up examinations to confirm successful bone graft fusion, after which the fixation was removed. Lumbar magnetic resonance imaging was performed before and 1 year after fixation surgery and 1 year after fixation removal. Modic and Pfirrmann grading standards were used to observe the effect of "temporary" fixation on the corresponding vertebral endplate and intervertebral disc.

RESULTS

All 30 patients had complete follow-up data available at 2 years postoperatively. The low back pain symptoms had disappeared completely, and radiographs and computed tomography showed that the isthmus in all patients had achieved bony fusion. With removal of the internal fixation, motion of the fixed segment recovered. "Temporary" rigid internal fixation did not increase the corresponding vertebral endplate or intervertebral disc degeneration.

CONCLUSIONS

"Temporary" short-segmental pedicle screw combined with transverse device fixation is a simple and effective method for adolescent isthmic spondylolysis with rigid internal fixation and accelerated bone graft fusion.

Drug shortages in Israel: regulatory perspectives, challenges and solutions

Background

Pharmaceutical drug shortages (DSs) are a global problem which presents challenges to countries around the world. Shortages of pharmaceutical products may have a direct detrimental impact on public health and patients’ wellbeing by causing delayed, or even lack of, treatment. Moreover, DSs may force both patients and caregivers to use unfamiliar drugs, which could lead to medication errors. The objective of our study was to analyze DSs in Israel during the years 2013–2015, assessing their etiology and exploring the steps taken for their mitigation and prevention.

Methods

The database of the Israeli Ministry of Health (MoH) on drug shortages contains all the DSs recorded in Israel since 2013, detailing the cause of the DS, its duration, steps taken in its’ management and the availability of generic or therapeutic alternatives. Selected examples of DSs from the database are described in this paper in order to identify the causes of DSs, the scope of the problem and possible solutions. Additionally, we have reviewed the recent activities performed by European Medicine Agency (EMA) and the American Food and Drug Administration (FDA) in their efforts to minimize this problem.

Results

Several factors contributing towards DSs in Israel were identified, including quality problems in both the final drug product and in the raw materials, upgrades and improvements of the manufacturing process required by the MoH, manufacturing by a sole supplier, dramatic price decrease in off-patent medications causing the manufacturer to discontinue the distribution of the product in Israel, just-in-time inventory control, and others.

One of the most important steps in managing drug shortages was identified to be early notification of the shortage by the Marketing Authorization Holder (MAH) to the MoH. In 2013, the Israeli MoH updated the regulation on drug shortages instructing MAHs on their obligation of early notification to the MoH.

Furthermore, various steps dealing with marketing withdrawal of drugs and temporary drug shortages are being implemented in Israel, such as suspending any further reductions in drug prices below 17 new Israeli shekels, instructing all MAHs to maintain no less than 1 month supply of all registered and non-registered drugs in Israel and allowing an expedited registration pathway for well-established use/grandfather drugs.

Conclusions

Drug shortages pose significant public health hazards worldwide. Early notification to the MoH and open dialog with MAHs are essential for managing DSs and mitigating their impact. Despite the efforts carried out by health regulatory authorities worldwide, DSs still pose a significant threat to public health.

Do flexicurity policies protect workers from the adverse health consequences of temporary employment? A cross-national comparative analysis

Flexicurity policies comprise a relatively novel approach to the regulation of work and welfare that aims to combine labour market flexibility with social security. Advocates of this approach argue that, by striking the right balance between flexibility and security, flexicurity policies allow firms to take advantage of loose contractual arrangements in an increasingly competitive economic environment while simultaneously protecting workers from the adverse health and social consequences of flexible forms of employment. In this study, we use multilevel Poisson regression models to test the theoretical claim of the flexicurity approach using data for 23 countries across three waves of the European Social Survey. We construct an institutional typology of labour market regulation and social security to evaluate whether inequalities in self-reported health and limiting longstanding illness between temporary workers and their permanent counterparts are smaller in countries that most closely approximate the ideal type described by advocates of the flexicurity approach. Our results indicate that, while the association between temporary employment and health varies across countries, institutional configurations of labour market regulation and social security do not provide a meaningful explanation for this cross-national variation. Contrary to the expectations of the flexicurity hypothesis, our data do not indicate that employment-related inequalities are smaller in countries that approximate the flexicurity approach. We discuss potential explanations for these findings and conclude that there remains a relative lack of evidence in support of the theoretical claims of the flexicurity approach.

Developing an in situ forming polyphosphate coacervate as a new liquid embolic agent: From experimental design to pilot animal study

A radiopaque temporary liquid embolic agent was synthesized from polyphosphate (PP) coacervates and optimized using a design of experiments approach. Variables studied were: strontium substitution (0-15 mol%), barium substitution (0-15 mol%), PP concentration and degree of polymerization of the polyphosphate (Dp). The viscosity, radiopacity and cell viability of the resulting coacervates were measured for 60 formulations and response surface modeling was used to determine the optimum coacervate that maximized radiopacity and cell viability. The optimum coacervate made from PP with a large Dp (9.5 g NaPP/100mL, 2.2 mol% Sr, 9 mol% Ba and 3.8 mol% Ca) was taken forward to a pilot animal trial. In this rabbit model, PP embolic agent successfully occluded the central auricular artery with promising biocompatibility. Further study is required to optimize the cohesiveness and clinical effectiveness of PP as an in situ setting temporary embolic agent.

STATEMENT OF SIGNIFICANCE

This article describes the development of a new radiopaque temporary liquid embolic agent from the optimization using design of experiments to a pilot animal study. Embolization is a minimally invasive interventional radiology procedure used to block blood flow in a targeted blood vessel. This procedure is used to treat many conditions including: tumors, aneurysms and arteriovenous malformations. Currently, no inherent radiopaque embolic agents are available in the clinic, which would allow for direct imaging of the material during the procedure and follow up treatment.

Hypohidrotic ectodermal dysplasia: a clinical case with a longitudinal approach

AIM

This paper describes a clinical case of a male with hypohidrotic ectodermal dysplasia submitted to rehabilitation and occlusal dental interventions with follow-up from 3 to 14 years of age.

BACKGROUND

Due to the severe effects on function and esthetics, the clinical manifestations of ectodermal dysplasia exert a negative impact on quality of life. However, oral rehabilitation in childhood poses a challenge due to growth and development.

CASE DESCRIPTION

A male with hypohidrotic ectodermal dysplasia began dental intervention at the age of 3 years. The clinical and radiographic exams revealed the absence of several primary and permanent teeth and abnormal shape of the primary maxillary incisors. The facial characteristics were compatible with hypohidrotic ectodermal dysplasia, such as a prominent brow, everted lips, fattened bridge of the nose and small vertical facial height. The treatment proposed involved rehabilitation through successive temporary partial dentures, functional orthopedics of the jaws, esthetic reconstruction of the anterior teeth, timely occlusal intervention and preventive actions for the control of dental caries and plaque.

CONCLUSION

The present case demonstrates that early care plays a fundamental role in minimizing the biopsychosocial consequences of hypohidrotic ectodermal dysplasia and preparing the patient for future oral rehabilitation.

CLINICAL SIGNIFICANCE

Although, the literature offers a number of papers describing dental treatment for ectodermal dysplasia, few cases include long-term follow-up and the use of a functional orthopedic appliance in combination with removable dentures in such patients.

How, when, and where have rental automated external defibrillators been used in Japan?

OBJECTIVE

Automated external defibrillators (AEDs) have been rented in various places in Japan. When rental AEDs are placed in locations where the probability of sudden cardiac arrest is high and permanent placement of AEDs is difficult, the possibility of improving survival rates might increase. In this preliminary study, we investigated how, when, and where rental AEDs have been used in Japan to clarify their characteristics when used in actual situations and to facilitate better usage in the future.

METHODS

We investigated the total number of AEDs rented, the duration of rental of each AED, the total number of AEDs rented monthly, the rental sites, the frequency and location of use, the number of defibrillations, and the time to defibrillation success for devices rented between January 2008 and December 2010 by a single company in Japan.

RESULTS

The number of AEDs rented annually was 590 at 391 sites in 2008, 767 at 465 sites in 2009, and 847 at 477 sites in 2010. More AEDs were rented during the summer. The devices were actually used on 17 individuals, of whom 2 individuals (at a beach and a marathon) underwent defibrillation, and 1 individual (at a marathon) survived.

CONCLUSION

Rental AEDs can play an important role in emergency cases occurring during seasonal and temporary outdoor events. The provision of rental AEDs in locations where permanent AEDs would be unfeasible may offer a useful strategy for efficiently improving survival rates in the future.

Chronological changes in the liver after temporary partial portal venous occlusion

AIM: To investigate time-dependent changes caused by temporal portal vein obstruction and subsequent reperfusion in the lobe with or without an occluded portal vein.

METHODS: The portal vein (PV) of the anterior lobe of the liver of a male Wistar rat (8 wk-old) was obstructed (70%) for 12, 24, 36 and 48 h, respectively, and models were sacrificed at 48 h after reperfusion (each group: n = 10). The histological changes and the status of liver regeneration were compared between a liver biopsy performed on each lobe after temporary obstruction of the portal vein in the same rat liver, and the liver extracted at the time of sacrifice (48 h after reperfusion).

RESULTS: With regard to the obstructed lobe, the liver weight/body weight ratio significantly decreased according to obstruction time. On the other hand, in the non-obstructed lobe, there were no significant differences within each group. The duration of PV occlusion did not seem to be strong enough to introduce liver weight increase. Stimulation of liver regeneration was brought about in the non-occluded lobe by 12-h occlusion, and was sustained even at 48 h after reperfusion. The obstructed lobe atrophied with the passage of time in the obstructed state. However, the proliferating-cell nuclear antigen labeling index also increased at 48 h after reperfusion, and a repair mechanism was observed.

CONCLUSION: Temporary blood flow obstruction of the portal vein may become a significant trigger for liver regeneration, even with an obstruction of 12 h.

[Temporary epicardial pacing following cardiac surgery: practical aspects]

OBJECTIVES

To review the practical aspects of temporary epicardial pacing following open heart surgery.

METHODS

Review of articles published in English or French within the last five years and investigating temporary epicardial pacing (indications, pacing modes, epicardial wires and temporary generators). The studies were extracted from the databases ScienceDirect and Pubmed.

RESULTS

Temporary epicardial pacing is used to treat severe conduction and/or rhythm disorders, but also to improve hemodynamics by optimizing selected temporary pacing settings. Temporary epicardial pacing consists in choosing the most suitable pacing mode according to the situation (surgery, patient, conduction and/or rhythm abnormalities) and setting its parameters that ensure : i) optimal pacemaker functioning; ii) epicardial electrodes longevity; iii) the most favorable hemodynamic profiles. Management of temporary pacing settings and their regular adjustment, at least daily and based on thresholds, are part of good clinical practices. Nevertheless, the French literature lacks official recommendations for temporary epicardial pacing.

CONCLUSION

Temporary epicardial pacing following cardiac surgery is a simple method, more effective than transcutaneous pacing and easier to implement than transvenous pacing. Its practical management should be known by all physicians (anesthetists, cardiac surgeons) as well as paramedical personnel in order to avoid the risks of suboptimal functioning. A good practice protocol is proposed at the end of the manuscript.

Coronal microleakage for readymade and hand mixed temporary filling materials

INTRODUCTION

The purpose of this in vitro study was to evaluate the sealing ability of the readymade temporary filling and hand mixed materials by assessing coronal microleakage.

MATERIALS AND METHODS

Standardized access cavities were prepared in 80 intact human permanent premolar teeth. They were divided randomly into four experimental groups (n=20). The teeth were restored using one of the temporary materials including Cavisol, Litrak, Zinc phosphate cement, Zinconol (IRM). Thermocycling was applied on the specimens. Methylene blue dye was applied and penetration was evaluated under stereomicroscope. Grading of the microleakage pattern was from 1 to 3, with 3 providing the best seal. Results were analyzed using one-way ANOVA test (P<0.05).

RESULTS

Microleakage of Cavisol and Litrak samples achieved grade 3; whereas zinc phosphate cement and Zinconol samples absorbed the dye into the bulk of the materials. Cavisol was found to exhibit the best seal amongst the four tested materials followed by Litrak, zinc phosphate cement, and Zinconol. There was a statistically significant difference in the microleakage scores obtained between the materials (P<0.01).

CONCLUSION

Among the four materials tested, readymade temporary filling provided the best sealing ability over hand-mixed. This study emphasizes the importance of correct placement and sufficient thickness of temporary filling materials in endodontic access cavities to ensure a tight seal.