Removable orthodontic appliances: frequency and cleaning agents used by students and recommended by dentists

Aim: To evaluate the prevalence and hygiene habits of 13-19 years-old adolescent users of removable orthodontic appliances (ROA) and to determine hygiene methods for the appliances prescribed by dentists, in the city of Pelotas. Methods: The study had two stages. The first stage was a telephone interview with dentists. Dentists were interview by telephone calls in order to obtain information regarding the hygiene methods for cleaning acrylic appliances. Second stage was a cross-sectional study performed with schoolchildren. Children from public and private schools with secondary level were included in the sample. A questionnaire was applied to the students using any type of ROA. Questionnaires included demographic information and behavioral characteristics. Data collected were subjected to Chi-square test and logistic regression. Results: The prevalence of children using ROA was 5.4%. Students (89.7%) and dentists (47.2%) reported to prefer mechanical methods to clean their ROA. Cleaning with soup, hydrogen peroxide or effervescent tabs were less used. High frequency of use was associated with higher frequency of hygiene on the ROA. Conclusions: The prevalence of schoolchildren using removable appliances was low. The common cleaning method used by children and prescribed by dentists was mechanical. Hygiene frequency was significantly associated with the routine of use of the appliance and with the type of hygiene method.

Odontometric analysis of molars for sex determination

Aim: To investigate the existence of sexual dimorphism between the first and second permanent molars. Methods: A cross-sectional, observational, blind study using comparative and statistical descriptive procedures. The sample included 50 pairs of plaster casts from undergraduate dental students (25 men/25 women) from the Federal University of Paraíba, João Pessoa/PB, Brazil, aged 20-26 years. Odontometric measurements of first and second maxillary/mandibular, right/left permanent molars were performed. Mesiodistal (MD) and buccolingual/palatal (BL/BP) widths and the distance between the lingual cusps of corresponding molars in opposite quadrants, were measured. The data were analyzed by Student’s t test and ANOVA with Bonferroni (p≤0.05). Results: The crowns of all first molars were statistically larger in men than in women (p<0.05). Maxillary and mandibular left second molars (#27 and #37) did not differ in their MD widths (p=0.66, p=0.75), whereas mandibular left and right second molars (#37 and #47) showed statistically different BL widths (p=0.007 and p=0.008). As to the distance between the lingual cusps, only the first left-to-right mandibular molars (#36-46) showed no sex dimorphism (p=0.107). Conclusions: Molars are larger in males than in females. Individually, first molars demonstrated higher evidence of sex distinction than second molars.

Antimicrobial and bond strength properties of a dental adhesive containing zinc oxide nanoparticles

Aim: To assess the effect of adding zinc oxide nanoparticles to dental adhesives on their anti-microbial and bond strength properties. Methods: 45 human premolars were cut at the cement enamel junction (CEJ) and the crowns were sliced into buccal and lingual halves. The specimens were classified into three groups, etched with 37% phosphoric acid for 15 s and rinsed for 30 s. Single Bond, Single Bond+5% zinc oxide and Single Bond+10% zinc oxide were used in the first, second and third groups. A cylinder of Z250 composite was bonded and cured for 40 s. For anti-bacterial testing, 10 samples of each group were assessed by direct contact test; 10 μL of bacterial suspension was transferred into tubes containing adhesives and incubated for one hour; 300 μL of brain heart infusion (BHI) broth was added to each tube and after 12 h, 50 μL of bacteria and broth were spread on blood agar plates and incubated for 24 h. Results: The colony count decreased significantly in the second and third groups compared to the first. Conclusions: Incorporation of zinc oxide nanoparticles into dental adhesives increases their anti-microbial properties without affecting their bond strength.

Cambios corticales en los dientes anteriores superiores e inferiores con Brackets convencionales, Damon y biofuncional QR en pacientes de trece a veinte y cuatro años

En el mercado existen varios sistemas de tratamiento en ortodoncia, los cuales deben ser estudiados para evitar que causen alteraciones en el periodonto, especialmente en los procesos alveolares corticales, por lo que el objetivo de este estudio fue conocer los cambios óseos alveolares, sean reabsorciones, aposiciones o ningún cambio óseo. Para realizar el estudio, se tomó como muestra tres sistemas de tratamiento: Sistema de Autoligado Damon, Sistema Biofuncional QR y Sistemas Convencionales Roth y MBT, estos brackets se aplicaron en 18 pacientes (seis de cada sistema), los cuales fueron sometidos a una tomografía antes del tratamiento y otra después de finalizada la etapa de alineación y nivelación. En los estudios tomográficos se realizaron trazados para medir en milímetros las corticales alveolares vestibulares, palatina y lingual, de los seis dientes anteriores superiores e inferiores, siendo la muestra total de 216 dientes. Para obtener los resultados del estudio, se ingresaron los datos recolectados en una hoja de cálculo Excel y procesados estadísticamente mediante el software SPSS versión 22, con las pruebas ANOVA y Tukey, obteniendo como resultados en el promedio de reabsorción ósea total p= 0,05 y con el Sistema Biofuncional QR una significancia de p= 0,025, en este último se demostró la presencia de aposición en la cortical lingual mandibular. Se concluyó que todos los sistemas de tratamiento causan reabsorciones óseas, siendo el Sistema Damon el de mayor reabsorción, seguido del Sistema convencional y luego el Sistema Biofuncional QR, produciendo este último una aposición estadísticamente significante. En los dientes anterosuperiores no existieron cambios óseos significativos y en los dientes anteroinferiores las mayores reabsorciones fueron en las piezas 42 y 32 y aposición en la pieza 41

Motivating the use of public transit through a mobile glanceable display

With increasing concerns about the impact of global warming on human life, policy makers around the world and researchers have sought for technological solutions that have the potential to attenuate this process. This thesis describes the design and evaluation of an information appliance that aims to increase the use of public transportation. We developed a mobile glanceable display that, being aware of the user’s transportation routines, provides awareness cues about bus arrival time, grounded upon the vision of Ambient Intelligence. We present the design process we followed, from ideation to building a prototype and conducting a field study, and conclude with a set of guidelines for the design of relevant personal information systems. More specifically we seek to test the following hypotheses: 1) That the tangible prototype that provides ambient cues will be used more frequently than a similar purpose mobile app, 2) That the tangible prototype will reduce the waiting time at the bus stop, 3) That the tangible prototype will result to reduced anxiety on passengers, 4) That the tangible prototype will result to an increase in the perceived reliability of the transit service, 5) That the tangible prototype will enhance users’ efficiency in reading the bus schedules and 6) That the tangible prototype will make individuals more likely to use public transit. In a field study, we compare the tangible prototype against the mobile app and a control condition where participants were given no external support in obtaining bus arrival information, other than their existing routines. Using qualitative and quantitative data, we test the aforementioned hypotheses and explore users’ reactions to the prototype we developed.

Adhesives for fixed orthodontic bands

Background: Orthodontic treatment involves using fixed or removable appliances (dental braces) to correct the positions of teeth. It has been shown that the quality of treatment result obtained with fixed appliances is much better than with removable appliances. Fixed appliances are, therefore, favoured by most orthodontists for treatment. The success of a fixed orthodontic appliance depends on the metal attachments (brackets and bands) being attached securely to the teeth so that they do not become loose during treatment. Brackets are usually attached to the front and side teeth, whereas bands (metal rings that go round the teeth) are more commonly used on the back teeth (molars). A number of adhesives are available to attach bands to teeth and it is important to understand which group of adhesives bond most reliably, as well as reducing or preventing dental decay during the treatment period. :Objectives: To evaluate the effectiveness of the adhesives used to attach bands to teeth during fixed appliance treatment, in terms of: (1) how often the bands come off during treatment; and (2) whether they protect the banded teeth against decay during fixed appliance treatment. Search methods: The following electronic databases were searched: Cochrane Oral Health's Trials Register (searched 2 June 2016), Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 5) in the Cochrane Library (searched 2 June 2016), MEDLINE Ovid (1946 to 2 June 2016) and EMBASE Ovid (1980 to 2 June 2016). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. Selection criteria: Randomised and controlled clinical trials (RCTs and CCTs) (including split-mouth studies) of adhesives used to attach orthodontic bands to molar teeth were selected. Patients with full arch fixed orthodontic appliance(s) who had bands attached to molars were included. Data collection and analysis: All review authors were involved in study selection, validity assessment and data extraction without blinding to the authors, adhesives used or results obtained. All disagreements were resolved by discussion. Main results: Five RCTs and three CCTs were identified as meeting the review's inclusion criteria. All the included trials were of split-mouth design. Four trials compared chemically cured zinc phosphate and chemically cured glass ionomer; three trials compared chemically cured glass ionomer cement with light cured compomer; one trial compared chemically cured glass ionomer with a chemically cured glass phosphonate. Data analysis was often inappropriate within the studies meeting the inclusion criteria. Authors' conclusions: There is insufficient high quality evidence with regard to the most effective adhesive for attaching orthodontic bands to molar teeth. Further RCTs are required.

Motivating the use of public transit through a mobile glanceable display

With increasing concerns about the impact of global warming on human life, policy makers around the world and researchers have sought for technological solutions that have the potential to attenuate this process. This thesis describes the design and evaluation of an information appliance that aims to increase the use of public transportation. We developed a mobile glanceable display that, being aware of the user’s transportation routines, provides awareness cues about bus arrival time, grounded upon the vision of Ambient Intelligence. We present the design process we followed, from ideation to building a prototype and conducting a field study, and conclude with a set of guidelines for the design of relevant personal information systems. More specifically we seek to test the following hypotheses: 1) That the tangible prototype that provides ambient cues will be used more frequently than a similar purpose mobile app, 2) That the tangible prototype will reduce the waiting time at the bus stop, 3) That the tangible prototype will result to reduced anxiety on passengers, 4) That the tangible prototype will result to an increase in the perceived reliability of the transit service, 5) That the tangible prototype will enhance users’ efficiency in reading the bus schedules and 6) That the tangible prototype will make individuals more likely to use public transit. In a field study, we compare the tangible prototype against the mobile app and a control condition where participants were given no external support in obtaining bus arrival information, other than their existing routines. Using qualitative and quantitative data, we test the aforementioned hypotheses and explore users’ reactions to the prototype we developed.

Load Profile Analysis Tool for Electrical Appliances in Households

This paper presents a methodology to forecast the hourly and daily consumption in households. The methodology was validated for households in Lisbon region, Portugal. The paper shows that the forecast tool allows obtaining satisfactory results for forecasting. Models of demand response allow the support of consumer’s decision in exchange for an economic benefit by the redefinition of load profile or changing the appliance consumption period. It is also in the interest of electric utilities to take advantage of these changes, particularly when consumers have an action on the demand-side management or production. Producers need to understand the load profile of households that are connected to a smart grid, to promote a better use of energy, as well as optimize the use of micro-generation from renewable sources, not only to delivering to the network but also in self-consumption.

Follicular wave synchronization on in vivo embryo production in Santa Ines sheep.

This study aimed to evaluate two hormonal protocols for synchronization of follicular wave emergence on in vivo embryo production in Santa Ines sheep under tropical conditions. The greater PRCL rate in GT probably contributed to the smaller number of viable embryos. Thus, it is suggested the appliance indicated the GEm protocol for in vivo embryo production in Santa Ines sheep under tropical conditions.