Use of a PLA Sleeve To Remove Electron Enhancement in Superficial X-Ray Therapy

A newly installed superficial x-ray unit was found to produce enhanced electron dose at the skin surface. ACPSEM guidelines suggest using nail varnish within the treatment cones as a method to reduce this dose. In this study, a 3D PLA sleeve was produced and used as an alternative to the nail varnish. Further, plastic wrap was also investigated for its anecdotal recommendations to reduce dose. It was found that a 1 mm printed sleeve, inserted into the treatment cone sufficiently reduced the enhanced dose to within approximately 3% of the dose measured with a Farmer-type chamber. The use of plastic wrap also reduced the enhanced dose, but impracticalities in its use make it non-viable for routine clinical use.

Pit and fissure depth in the enamel of mandibular third molars: An open gate for microleakage?

The aim of this descriptive ex vivo study was to evaluate qualitatively the depth of pit and fissures (P&F) of the enamel in human mandibular third molars. Fifty (n=50) extracted human mandibular third molars were cleaned and disinfected. All tooth surfaces were coated with nail varnish except for a 1-mm margin around the periphery of the occlusal surface. The teeth were immersed for 48 hours at 37 °C in 1% methylene blue dye solution prepared in artificial saliva. After cleaning, the crowns were separated from the root at the cementoenamel junction and subsequently sectioned longitudinally in buccolingual direction at the location of the central fossa. All sections were examined using a stereoscopic microscope and photographed. The images were downloaded on a computer. The length of penetration of the P&F was recorded using the following scoring system: C1: P&F extended to half of the enamel thickness; C2: P&F extended beyond half of the enamel thickness without reaching the dentine-enamel junction; C3: P&F extended to the dentine-enamel junction. For pits, C1, C2 and C3 were observed in 35, 9 and 6 teeth, respectively, while for fissures, C1, C2 and C3 were observed in 15, 18 and 17 teeth, respectively. The P&F detected in the samples extended to the deepest portions of enamel, quite frequently reaching the enamel-dentine junction. Clinicians should recognize that even if pits and fissures are not clinically obvious, they penetrate deep into the enamel and frequently reach the dentine-enamel junction. Effective treatment is recommended to block access to P&F, thus preventing ingress of bacteria.

In Vitro Microleakage Evaluation of Bioceramic and Zinc-Eugenol Sealers with Two Obturation Techniques

Aim of the study is to compare the quality of the apical seal offered by a zinc-eugenol and a tricalcium-silicate-based sealer, both used with the single-cone or with the continuous wave of condensation technique. Forty central incisors were divided into four groups (n = 10), according to the two sealers and the two obturation techniques under investigation, and their outer surface was isolated with nail varnish. After endodontic treatment, samples were immersed in methylene blue dye for 72 h, then included in self-curing resin and sectioned to longitudinally expose the canal apical third. The depth of dye penetration was measured in each group. Mean values were compared by two-way-ANOVA test. Multiple comparisons were performed by Tukey test. The level of significance was set at 0.05 in all tests. The continuous wave of condensation technique led to reduced microleakage. Moreover, dye penetration values were reduced for the tricalcium-silicate sealer. In terms of microleakage, the warm continuous wave of condensation technique seems promising even when combined to a bioceramic sealer.

Artificial Caries Lesion Characteristics after Secondary Demineralization with Theobromine-Containing Protocol

Developing artificial caries lesions with varying characteristics is needed to adequately study caries process in vitro. The objective of this study was to investigate artificial caries lesion characteristics after secondary demineralization protocol containing theobromine and fluoride. Sixty bovine enamel slabs (4 × 3 mm) were demineralized using a Carbopol-containing protocol for 6 days. A baseline area (2 × 3 mm) was protected with acid-resistant nail varnish, after which specimens were exposed for 24 h to a secondary demineralization protocol containing acetic acid plus one of four fluoride/theobromine combinations (n = 15): theobromine (50 or 200 ppm) and fluoride (0 or 1 ppm). Specimens were sectioned and analyzed using transverse microradiography for changes in mineral content, lesion depth, and surface layer mineralization. Data was analyzed using paired t-test and analysis of variance followed by Bonferroni test at 0.05 significance level. After secondary demineralization, fluoride-containing groups had significantly deeper lesions (p = 0.002 and 0.014) compared to the group with 0 ppm fluoride and 50 ppm theobromine. Mineral content and lesion depth were significantly different compared to baseline for all groups. Theobromine did not show an added effect on mineral uptake. Theobromine-containing groups exhibited particularly deep lesions with a more uniform mineral profile in the presence of fluoride.

Application of a novel banding technique and photographic recapture to describe plumage development and behaviour of juvenile Fairy Terns

The Australian Fairy Tern Sternula nereis nereis is a seabird that breeds along the coast and whose small populations are dispersed over vast stretches of the Australian seaboard and nearshore islands. In recent years, citizen science programs have been developed to bolster monitoring efforts to better understand breeding success and identify site threat profiles. The development of protocols that facilitate the collection of consistent measurements is important for long-term monitoring of this threatened (Vulnerable) species. This study describes plumage development and age-related behaviour in juvenile Australian Fairy Terns using direct observations and photographic recapture of individually marked birds. This information may be used as the basis for the development of a field ageing guide, enabling the collection of standardised information on colony demographics and juvenile development. A temporary colour-banding study was trialled by painting nail varnish onto 15 Australian Bird and Bat Banding Scheme (ABBBS) incoloy bands, avoiding the need to band nestlings with additional readable or PVC colour-bands. The varnish remained intact, albeit chipped, on four surviving birds that were resighted ≤80 days after banding, enabling the identification of individuals away from the colony site, without the need for recapture. The temporary marking of ABBBS bands using nail varnish offered an effective short-term solution for identifying individual juvenile Fairy Terns in the field and for describing plumage changes over a period of c. 3 months.

Risco Biológico e/ou Químico eventualmente associado ao uso de adereços pelo Trabalhador (como anéis, alianças, relógios, pulseiras)

Introduction/ background/ objectives There are some manuals of Good Practices, in some professional sectors, that highlight the need to stop use jewelry at work (such as finger rings, watches, bracelets and/ or equivalent), relating to the potentialization of contact with biological agents and/ or chemical. The studies dedicated to this theme are very scarce and all related to health professionals; although, in many other sectors, it is a relevant topic, like in food production, tattooing, preparation of equipment that needs to be sterile and any sector that deals with chemical agents, for example. Methodology It is an Scoping Review, initiated through a research conducted in December 2019 in the databases “CINALH plus with full text, Medline with full text, Database of Effects Review Abstracts, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Cochrane Methodology Record, Nursing and Allied Health Collection: comprehensive, MedicLatina, Scopus and RCAAP ”. Content The use of finger rings decreases efficacy of hand washing, since some bacteria can remain in microscopic irregularities under the ring. In addition, they can tear the protective gloves; even so, the use of this individual protective equipment attenuates the microbial load of the rings. However, some investigators argue that there is no statistical evidence that the use of rings will alter postoperative infraction rates. Those with smooth surfaces, like classic wedding rings, do not appear to be so problematic. As for watches and bracelets, it appears that they do not contribute to a significant increase in the rate of infringement; yet some researchers recommend that they be removed, before hand washing. The use of nail varnish decreases efficacy of hand washing, since some bacteria can remain in the microscopic irregularities of the varnish; however, there is no robust statistical evidence that the use of varnishes alters the rate of postoperative infection. Long nails have a higher microbial load, especially if recovered by irregular varnish (with a few days). In addition, big nails can also increase the likelihood of tearing the glove, whether natural or artificial. So it makes sense that some professionals use them short. Since scientific evidence that correlates hospital infection to the use of artificial jewelry or nails among healthcare professionals is not very robust, the norms at some institutions are in the format of recommendations only. Conclusions Studies are scarce and do not appear to be concordant or robust on several occasions, so it would be useful that Occupational Health teams, from companies with biological and/ or chemical risk, design and carry out studies and, subsequently, publish it to specialty magazines. In doubt, until clear evidence appears, objects such as finger rings, rings, watches and bracelets should be removed before work and hand washing and the size of long/ artificial nails or varnish must be carefully pondered.

Effect of dispensing method and curing modes on the microleakage of composite resins

Background: Vibration decreases the viscosity of composite, making it flow and readily fit the walls of the cavity. This study is initiated to see how this improved adaptation of the composite resin to the cavity walls will affect microleakage using different curing modes Materials and methods: Standard Class V cavities were prepared on the buccal surface of sixty extracted premolars. Teeth were randomly assigned into two groups (n=30) according to the composite condensation (vibration and conventional) technique, then subdivided into three subgroups (n=10) according to light curing modes (LED-Ramp, LED-Fast and Halogen Continuous modes). Cavities were etched and bonded with Single Bond Universal then restored with Filtek® Z350 (3M ESPE, USA). In the vibration group, condensation was done using CompothixoTM (Kerr, Switzerland). In the conventional group, condensation was done with hand plugger. Curing modes for all groups were LED-Ramp, LED-Fast and halogen continuous modes, respectively. Samples stored in distilled water at 37°C for seven days, and painted completely with two layers of nail varnish with only 1 mm around the composite restoration left. Samples were thermocycled, immersed in 2% methylene blue solution for 3 hours, and sectioned longitudinally. Dye penetration was assessed under a stereomicroscope. Data were analyzed by Kruskal-Wallis and Mann-Whitney U tests with p <0.05 considered significant. Results: Vibration group showed less microleakage (P=0.028). In the conventional group there were no differences by using different curing modes (P=0.277). In the vibration group no differences were found between LED-Ramp and LED-Fast mode (P=0.989). However, there were significant differences between LED-Fast and halogen (P=0.05) and between LED-Ramp and halogen group (P=0.001). Microleakage scores of all cervical walls were higher than the occlusal walls (P=0.001). Occlusal walls leakage for conventional and vibration groups were not different (P=0.475), while there were significant differences between them at cervical walls (P=0.001). Conclusion: Vibration with LED-Ramp curing mode may decrease marginal leakage of composite restoration placed in Standard Class V tooth preparations. Keywords: Composite resin, Vibration, Condensation, Compothixo, Microleakage,

Nail varnish helps researchers pinpoint numbers of rare bats

Emma Huntley explains how researchers from the Zoological Society of London are using an inventive way to calculate bat populations