Effects of non-thermal atmospheric plasma treatment on dentin wetting and surface free energy for application of universal adhesives

Objectives

The study aims to evaluate the effects of non-thermal atmospheric plasma (NTAP) treatments on dentin wetting and surface free energy (SFE) and compare the effects of NTAP treatment, etch-and-rinse, and self-etch protocols for application of universal adhesives.

Materials and methods

Mid-coronal dentin of intact third molars was used to measure contact angles of distilled water, ethylene-glycol, and diiodomethane and calculate SFE following different NTAP preset treatments (feeding gas consisting of pure He, He + 1% O₂, He + 1.5% O₂), power input (1 or 3 W), and tip-to-surface distance (2, 4, or 8 mm). Contact angles of reference liquids and SFE of dentin following He + 1.5% O₂ at 3-W and 4-mm treatment was compared to phosphoric acid etching. Contact angles of Single Bond Universal (SBU; 3M ESPE) and Clearfil Universal Bond (CUB; Kuraray Noritake) were measured following NTAP, etch-and-rinse, and self-etch protocols.

Results

NTAP significantly reduced contact angles of reference liquids and increased dentin SFE compared to untreated dentin (p < 0.05). O₂ intensified the effect of He NTAP (p < 0.05). NTAP and phosphoric acid increased dentin polarity and Lewis base surface characteristics. Phosphoric acid increased contact angles of adhesives compared to the self-etch protocol (p < 0.05). NTAP resulted in lower adhesive contact angles than phosphoric acid, the difference being statistically significant for CUB (p < 0.05). Compared to the self-etch protocol, NTAP slightly reduced CUB contact angle but not that of SBU (p > 0.05).

Conclusions

He NTAP with and without O₂ increased dentin wetting and SFE, surpassing the effect of phosphoric acid and lowering adhesive contact angles. NTAP produced no apparent micro-morphological changes on dentin surface comparable to acid etching.

Clinical significance

NTAP treatment of dentin prior to adhesive application increases dentin wetting and surface free energy facilitating better adhesive distribution on dentin surface compared to phosphoric acid etching and similar to the “self-etch” application protocol.

     

Degenerative neurological disorders associated with deficiency of glutamate dehydrogenase

Summary The activity of glutamate dehydrogenase, the enzyme of glutamate degradation, was measured in platelets of 27 healthy controls and 85 patients with different degenerative cerebellar and/or basal ganglia disorders. A group of 7 patients was selected with slowly progressive multiple-system atrophy, in whom a clinical diagnosis of olivopontocerebellar atrophy appeared tenable, with decreased activity of glutamate dehydrogenase (38% of the mean control value). In 4 patients data on inheritance were compatible with the genetic pattern of autosomal recessive inheritance, while 3 patients were sporadic cases. In an effort to define this group of patients more precisely, it is suggested that decreased activity of glutamate dehydrogenase induces an increase in extracellular glutamate levels in the central nervous system with subsequent development of excitotoxicity.     

Role of nimodipine in the therapy of subarachnoid and intracerebral hemorrhage

Syndromes of intracranial hemorrhage, and particularly subarachnoidal, i.e., intracerebral hemorrhage (SAH and IH) present clinical entities that are the most severe conditions in neurology. Timely recognition, diagnosis and adequate therapy are imperative. The most important factor that aggravates an already difficult prognosis of those entities is cerebral vasospasm. Upon the presented facts, the aim of this investigation was to establish the value and role of administration of selective calcium channel blocker--nimodipine in patients with SAH and IH compared to the degree of neurological and functional impairment, as well as the recovery of the function of consciousness compared to the patients with those syndromes from an earlier period, who were not treated with this medicament. Investigation comprised 30 patients who received nimodipine and 20 patients without this agent in therapeutic program. Results of the investigation confirmed significant difference concerning the neurological recovery, improvement of functional capability and recovery or consciousness disturbances, respectively, in patients who received nimodipine compared to the group without this agent. It can be concluded that nimodipine as calcium channel blocker with multitopic pharmacological effects on mechanism of SAH or IH development, respectively, as well as on the development of complications of those syndromes, particularly to the development of vasospasm and reactive ischemia, with the improvement of hemorrheologic disorders deserves to be included as the unavoidable segment of therapeutic program of SAH and IH syndrome immediately after clinical phenomenology is revealed.     

Secondary neurosurgical management of craniocerebral war injuries

In Belgrade Military Medical Academy 88 males and 1 female (aged 13-55, average 28.6 years) with war craniocerebral injuries (CCI) were secondarily neurosurgically treated from October 1991 trough December 1992. Primary neurosurgical management of these patients was performed in war hospitals in former Yugoslavia. Out of 89 patients, 78 had penetrating, and 11 closed CCI. Out of 55 patients with penetrating CCI who underwent surgery, intracranial debridement was performed in 34 patients. All patients with severe CCI (GCS = 3-8) were severely by disabled or died, and in the majority of patients with minor CCI (GCS = 13-15) the outcome was good (p < 0.01). Statistical analysis showed no significant correlation between the extent of cerebral lesion and the outcome of penetrating CCI (p > 0.05). Eight (10.3%) patients with penetrating CCI died. The outcome of war CCI mostly depended on the severity of injury.     

Acute myeloid leukaemia in patients we judge as being older and/or unfit

The definition of older age in AML is arbitrary. In the context of the clinical studies, it starts with age ≥60 or ≥65 years and in recent years ≥70 or 75, depending on the selection of the studied population. In clinical practice, with older age, we often mean that the patient is unfit for intensive chemotherapy. Higher age overlaps with categories such as worse performance status, unfitness, comorbidities, poor-risk cytogenetics, adverse mutation patterns, age-related clonal haematopoiesis and specific disease ontogeny. Intensive induction therapy can result in prolonged overall survival, at least in a subset of elderly patients aged up to 75 years despite the reluctance of some physicians and patients to use treatment regimens perceived as toxic. Venetoclax and azacitidine combination is the new standard of comparison for persons unfit for intensive therapy. New oral hypomethylating agent CC-486 as maintenance therapy led to a prolonged overall survival in a randomized trial of patients ≥55 years of age who were in first complete remission, but not eligible for allogeneic stem cell transplantation. Any therapy is better than no therapy, but a substantial proportion of older patients still receive only palliative care. Making a decision for AML diagnosed in older age should be individualized and shared through the dialog with the patient and relatives or cohabitants, considering medical issues and social factors including personal goals. Although we are witnesses of the advances in basic research and therapy, we are still a very long way from curing older patients with AML.     

A model of the viscoelastic behavior of flowable resin composites prior to setting

Objective

The aim of this study is to develop fractional derivative models for the assessment of viscoelastic properties related to handling characteristics of dental resin composites belonging to two classes: flowable (Revolution Formula 2 and Filtek Ultimate) and posterior “bulk-fill” flowable base (Smart Dentin Replace).

Methods

Rheological measurements on all materials tested in this study were performed using dynamic oscillatory rheometer at temperature of 23 °C. A parallel plates module with a diameter of 20 mm was used to measure the properties of the resin composites tested. We developed two models to describe the obtained data: the generalized Newton model and the generalized Zener model (the so-called three parameter model). Both models contain fractional derivatives of Riemann–Liouville type. By determining the parameters of the model we were able to fit experimental data with high accuracy.

Results

Our results show that flowable “bulk-fill” resin-composite material (SDR) has distinct properties as compared to other two flowable resin composite materials (Revolution Formula 2 and Filtek Ultimate). Thus, previously found SDR properties as “bulk-fill” flowable base results in the fact that it is described by generalized Zener model (i.e., it has properties of solid like viscoelastic material).

Significance

Our model may be used to predict behavior of tested composites in different flow conditions. The SDR has initially small almost constant complex viscosity showing that it has good self-leveling property.     

Warren shunt combined with partial splenectomy for children with extrahepatic portal hypertension, massive splenomegaly, and severe hypersplenism

Purpose

To establish the importance of shunt surgery combined with partial resection of the spleen for selected pediatric patients with extra-hepatic portal vein obstruction (EHPVO), enormous splenomegaly and severe hypersplenism. Severe hypersplenism is often refractory to treatment with endoscopic sclerotherapy or band ligation and shunt surgery; however, to our knowledge, this is the first such study to be published.

Methods

Distal splenorenal shunt with partial resection of the spleen was performed in 16 of 60 children treated for EHPVO in the Gastroenterology Department of our hospital. Upper gastrointestinal endoscopy had shown esophageal varices of varying grade in all patients and band ligation or endoscopic sclerotherapy had been done for children with a history of bleeding. The indications for surgery were pain and discomfort caused by a large spleen (5–15 cm below the costal margin) and symptomatic hypersplenism with leucopenia, thrombocytopenia, and anemia. Partial resection of the spleen was performed, starting with ligation of the branches and tributaries of the caudal two-thirds. When an ischemic line demarcated the splenic parenchyma, it was transected using electrocautery or LigaSure, leaving 20–30 % of splenic tissue. After the spleen resection, a Warren shunt was performed. Platelet and white blood cell counts and liver function tests were performed before and after the operation. Growth was assessed using SD scores (z scores) for height, weight, and body mass index at the time of surgery and 1 year later.

Results

Postoperative recovery was uneventful and the leukocyte and platelet counts normalized. The shunt patency rate was 100 %. Two cases of shunt stenosis were treated successfully with percutaneous angioplasty. There was no postoperative mortality. During the follow-up period, from 1 to 7 years, all 16 children were asymptomatic, with improved quality of life, growth, and nutrition. No episodes of variceal bleeding, sepsis or encephalopathy occurred.

Conclusion

Our results demonstrate that shunt surgery with partial resection of the spleen is effective and safe for pediatric patients with massive splenomegaly and severe hypersplenism secondary to EHPVO.