Effects of Hybridized Synthetic Fibers on the Shear Properties of Cement Composites

The use of fibers in cementitious composites yields numerous benefits due to their fiber-bridging capabilities in resisting cracks. Therefore, this study aimed to improve the shear-resisting capabilities of conventional concrete through the hybridization of multiple synthetic fibers, specifically on reinforced concrete structures in seismic-prone regions. For this study, 16 hybrid fiber-reinforced concretes (HyFRC) were developed from the different combinations of Ferro macro-synthetic fibers with the Ultra-Net, Super-Net, Econo-Net, and Nylo-Mono microfibers. These hybrids were tested under direct shear, resulting in improved shear strength of controlled specimens by Ferro-Ultra (32%), Ferro-Super (24%), Ferro-Econo (44%), and Ferro-Nylo (24%). Shear energy was further assessed to comprehend the effectiveness of the fiber interactions according to the mechanical properties, dosage, bonding power, manufactured material, and form of fibers. Conclusively, all fiber combinations used in this study produced positive synergistic effects under direct shear at large crack deformations.     

The Effect of Sonophoresis on Topical Anesthesia: A Pilot Project

The dental anesthesia sonophoresis device (DASD) is a novel device that is intended to reduce the discomfort associated with intraoral mucosa needle puncture. The DASD produces ultrasonic energy that provides a sonophoretic effect on the oral mucosa, generating microchannels through the lipids between the keratinized cells that make up the stratum corneum. Once the topical anesthetic has permeated the stratum corneum, it quickly diffuses through the soft tissue, desensitizing the nerve endings and reducing the perception of pain caused by needle penetration. The aim of this study is to evaluate whether topical anesthesia applied using the DASD will reduce the discomfort of the needle puncture when compared to the control device. A split-mouth model, using 50 healthy subjects with puncture site at the maxillary canine vestibule, was used for this study. Subjects received a needle puncture on both sides of the mouth. Prior to the needle puncture, there was randomized application of 5% lidocaine with the DASD and a control device. Subjects rated their discomfort after needle punctures utilizing the visual analog scale pain scoring system. There was no statistically significant difference in the pain perception using the DASD versus the control device.Key Words: Dental anesthesia sonophoresis device, SonophoresisSonophoresis, which is low-frequency ultrasound, has been shown to enhance transdermal transport of various drugs, including macromolecules. Enhancement from sonophoresis occurs by disordering the structured lipids in the stratum corneum. Although sonophoresis has been shown to be effective on the skin, its effect has not been studied intraorally. The development of the dental anesthesia sonophoresis device (DASD), a device whose design was specially developed for the application of sonophoresis in the oral cavity, has opened the door for exploration in the benefits and effectiveness of sonophoresis application in the dental field. Fear of intraoral local anesthetic injection is one of the main reasons people avoid dental treatment.¹ Many investigators, using a variety of different techniques, have explored reducing the pain and discomfort of the dental injection. The majority of research has focused on the application of topical anesthesia.The results are inconsistent with regard to the effectiveness of topically applied anesthetic. Some studies show that there are no significant differences when compared to the placebo.^2–5 On the other hand, there are several studies that support the efficacy of topical anesthetic.^3,6–9Duration of application has been isolated as an important factor to achieve adequate topical anesthesia. Meechan¹⁰ summarizes that the degree of topical anesthesia penetration and its effectiveness are governed by the duration of application. It has been suggested that success of topical anesthesia is guaranteed when used in the buccal fold of either jaw after a 5-minute application.¹¹ Due to the lack of consistency in the literature regarding the effectiveness of topical anesthesia, there is need for continued research and improvement.Topical anesthetic must cross the physical barrier of the intraoral mucosa to reach the underlying nerve receptors. The free nerve endings are located close to the basal surface of the oral epithelium.¹² The location of these free nerve endings only reinforces the importance of the topical anesthetic passing through the oral mucosa barrier. The intraoral mucosa, like the skin, consists of stratified squamous epithelium with different layers of cells. The most superficial layer is the stratum corneum, which is filled with short stacks of lipid lamellae.¹³ This lipid layer makes it difficult for substances to cross the stratum corneum. To demonstrate this, Squier¹⁴ showed that horseradish peroxidase could not penetrate the top 3 layers of the oral mucosa of 3 mammals when applied topically.Attempts have been made to improve the penetration of topical anesthetics across this anatomic barrier. Hutchins et al⁷ studied the effect of vibration with a placebo and vibration with 20% benzocaine on pain of intraoral injections, and found vibration had no effect on reducing pain. Others have studied the use of iontophoresis and phonophoresis for application of anesthesia.^15,16 Research suggests that skin anesthesia by application of a topical anesthetic can be expedited through iontophoresis; however, this still requires a minimum of 10 minutes at relatively high voltage.¹⁷Ultrasound has been shown to enhance transdermal transport of various drugs, including macromolecules. This type of enhancement is termed sonophoresis, indicating the enhanced transport of molecules under the influence of ultrasound.¹⁸The DASD is a novel device intended to expedite penetration of topical anesthetic with a faster onset of clinical effectiveness. The DASD is a portable, battery-powered device that simultaneously generates ultrasonic energy and sonic vibration in a small applicator head that can easily reach and adapt to injection sites in the oral cavity. The ultrasonic energy is in small bursts of 300–350 kHz that provide a sonophoretic effect on the oral mucosa. The manufacturer claims the DASD works by generating microchannels through the lipids in the stratum corneum. The sonic vibration is provided simultaneously with the ultrasonic energy in the form of sinusoidal motion ranging from 200–300 Hz. This vibration helps to randomize and distribute the sensation associated with the ultrasonic energy. Once the topical anesthetic has permeated the stratum corneum, it quickly diffuses through the soft tissue, desensitizing the nerve endings. The purpose of this study is to evaluate whether topical anesthesia applied using the DASD will reduce the discomfort of the needle puncture when compared to the control device. The null hypothesis is that there is no difference of perceived discomfort between the DASD and the control device (CD).     

Atrial fibrillation during myocardial infarction with and without ST segment elevation

INTRODUCTION: The occurrence of atrial fibrillation (AF) in the acute phase of myocardial infarction with ST segment elevation is common and responsible for an excess hospital mortality. The aim of this work was to define the incidence, predictive factors, and the prognostic impact of AF during MI with and without raised ST segment in the RICO study. PATIENTS AND METHODS: Between January 2001 and July 2003, 1701 patients were included in this study: 130 (7.6%) had AF in the first 24 hours of management (AF+ group); 1571 (92.4%) remained in sinus rhythm (AF- group). RESULTS: Among the 1701 patients included in this study, 1197 (70.4%) had MI with raised ST and 504 (29.6%) had MI without raised ST. The incidence of AF was identical whatever the type of MI (7.6% with raised ST versus 7.7% without, p=0.334). The presence of Killip class >2 on admission and chronic obstructive pulmonary disease were independent predictive factors for the occurrence of AF (OR=3.84, p=0.007, and OR=2.47, p=0.014 respectively). The presence of AF was significantly associated with the occurrence of ventricular arrhythmia and/or cardiovascular mortality during admission in the non-selected MI population whatever the type of MI (raised ST ; AF+; 34% and AF-; 18%, p<0.01 versus without raised ST; AF+; 36% and AF-; 16%, p = 0.01). CONCLUSION: This study provides evidence that the incidence of AF during the first 24 hours of MI, as well as its poor prognosis, are identical whether or not there is ST segment elevation.     

Is the burden of oral diseases higher in urban disadvantaged community compared to the national prevalence?

Background

The urban low income has often been assumed to have the greatest dental treatment needs compared to the general population. However, no studies have been carried out to verify these assumptions. This study was conducted to assess whether there was any difference between the treatment needs of an urban poor population as compared to the general population in order to design an intervention programme for this community.

Methods

A random sampling of living quarters (households) in the selected areas was done. 586 adults over 19 years old living in these households were clinically examined using World Health Organization (WHO) Oral Health Survey criteria 4th edition (1997).

Results

The overall prevalence of dental caries, periodontal disease, denture wearers and temporomandibular joint problems were 70.5%, 97.1%, 16.7% and 26%, respectively. The majority (80.5%) needed some form of dental treatment. The highest treatment needs were found in the oldest age group while the lowest were in the youngest group (19-29 years) (p = 0.000). The most prevalent periodontal problem was calculus; regardless of gender, ethnicity and age. Significantly more females (20.5%) wore prosthesis than males (11.1%) (p = 0.003). Prosthetic status and need significantly increased with age (p = 0.000). About one in four adults had Temporo-Mandibular Joint (TMJ) problems. Overall, it was surprising to note that the oral disease burden related to caries, prosthetic status and treatment need were lower in this population as compared to the national average (NOHSA, 2010). However, their periodontal disease status and treatment needs were higher compared to the national average indicating a poor oral hygiene standard.

Conclusions

The evidence does not show that the overall oral disease burden and treatment needs in this urban disadvantaged adult population as higher than the national average, except for periodontal disease. The older age groups and elderly were identified as the most in need for oral health intervention and promotion. An integrated health intervention programme through a multisectoral common risk factor approach in collaboration with the Faculties of Medicine, Dentistry and other agencies is needed for the identified target group.

     

Forced-eruption time for palatally impacted canines treated with and without ostectomy-decortication technique

Objectives:To compare forced-eruption times for palatally impacted canines treated with and without the ostectomy-decortication technique and to assess the influence of palatally impacted canine pretreatment position and angle on forced-eruption time.Materials and Methods:The sample was composed of 118 patient-subjects with 151 palatally impacted canines treated with the ostectomy-decortication technique (n = 72) and without (n = 79). The orthopantomogram radiographs (OPGs) were analyzed for palatally impacted canine angle and horizontal and vertical position. Recovery time was measured from the start of forced eruption until the canine was within ±1 mm of final dental arch position.Results:The time of forced canine eruption with ostectomy-decortication technique was significantly shorter than without (6.6 vs 21.0 months). Pretreatment canine position significantly increased forced-eruption time in the ostectomy-decortication group but not in the control sample.Conclusions:Forced-eruption time of palatally impacted canines using the ostectomy-decortication technique was 3.2 times more rapid than without. Forced-eruption time increased significantly as a function of pretreatment palatally impacted canine position severity in the ostectomy-decortication group but not in the control.     

Prevalence and pattern of upper limb involvement in cerebral palsy

Purpose

The aim of this study was to determine the prevalence and pattern of upper limb involvement in children with cerebral palsy (CP), how this relates to function and how well these problems are recognised and treated.

Methods

One hundred consecutive patients with CP attending non-hand-related clinics were assessed. Function was assessed according to the Gross Motor Functional Classification System (GMFCS), the Manual Ability Classification System (MACS) and the ABILHAND-Kids system, and correlated to age and pattern of upper limb involvement. Patients were examined for contractures in the shoulder, elbow, wrist and hand. Concerns about the appearance of the hand were also assessed in older children.

Results

Overall, 83 % of patients had upper limb involvement, 36 % had a demonstrable contracture and 69 % had reduced hand control. The most common contracture patterns were the thumb in palm with clasp hand, shoulder adduction with internal rotation and wrist flexion with pronation. The thumb in palm with clasp hand pattern was associated with the greatest functional disability, followed by wrist flexion with pronation. Single contractures such as elbow flexion caused significant disability, whereas swan-neck contractures were, by far, less debilitating. Children aged 12 years and older had more concerns about the appearance of their hand. The ABILHAND score was strongly correlated to both the GMFCS and the MACS score.

Conclusion

Different patterns of upper limb involvement exist in CP and some have a significant impact on function and cause cosmetic concerns that should not be underestimated, particularly in older children.