Programação, conexão e avaliação de psicrômetro aspirado de termopar de baixo custo em micrologger para estudos agrometeorológicos

As the psychrometric method is considered standard for the measurement of relative humidity, many studies have used aspirated thermocouple psychrometers connected to microloggers but, however, they do not detail how the aspiration of the air stream is done. However, one of the major difficulties of aspirated thermocouple psychrometers is to program and to connect it in micrologger, because specific programming and connection are requires, and still some skills in getting accurate measurements. This work aimed to provide the programming and the connection of the aspirated thermocouple psychrometer type T for the CR10X microloggers and CR23X of Campbell Scientific, evaluating the quality of measurements of temperature and air relative humidity in relation the a sensor Vaisala HMP50. The non-continuous measurements were made in the period 2006/09/04 to 2007/07/11 at Jaboticabal, SP. The air temperature measurements were similar between the Vaisala sensors and aspirated thermocouple psychrometer, but the relative humidity measurements were significantly different. The measurements obtained by the aspirated thermocouple psychrometer connected to CR10X micrologger were the most accurate. Using the programming and connection of a micro-fan to suck in the dry and moist bulbs of aspirated thermocouple psychrometer in microloggers models CR10X and CR23X, it is possible to obtain measurements of air temperature with good precision and accuracy, and measurements of air relative humidity with good precision, but accuracy is not always attainable due to the difficulties inherent to the physical processes that occur in the wet bulb, the skill in the use and maintenance of this equipment and the reservoir protection against radiative effects.

Temperature and scarification on seeds germination of copernicia prunifera (Mill) H.E. Moore (Arecaceae)

Copernicia prunifera, known as carnauba, is native to Brazil and presents great potential to be used in gardens and cultivation in pot. Palms species, with relatively few exceptions, can only be propagated by seeds; even so, there are no reports in the literature about the germination of this palm seeds. Several species of the Arecaceae family present seed physical dormancy in varying degrees, demanding treatments to improve germination. The objective of this work was to study the effects of temperature and mechanical scarification on seed germination of C. prunifera. The experimental design was entirely randomized in a factorial arrangement 6 x 2 (six conditions of temperature with or without mechanical scarification) with 4 replications and 25 seeds each. In accordance with the treatment, lateral scarifications were made on the seeds until appearance of the endosperm. Seeds were sown in moist fine vermiculite. Germination (%) and germination rate (GR) were evaluated. Germination data were arcsine (x/100)1/2 transformed before analysis of variance and germination rate data were not transformed. The means of the resulting values were then compared by the Scott-Knott test at 1% confidence level. It was concluded that the biggest germination percentage were obtained at alternated temperature of 25-35°C (92%) and at constant temperature of 25°C (87%). Seeds germinated faster at alternated temperature of 25- 35°C. Germination percentage was similar for the scarified and non-scarified seeds; however, scarified seeds germinated faster.

Performance of race instrumentation system in curved root canals: a comprehensive analysis by three study methods

In this study, curved maxillary molar root canals were instrumented with RaCe rotary system to evaluate: 1. the occurrence of canal transportation using a radiographic platform; 2. the action of the instruments on the dentin walls, centering ability and canal enlargement by analysis of digital images; and the percentage of regular dentin surfaces and debris within the canal by histological analysis. Ten mesiobuccal roots of extracted human maxillary molars were embedded in acrylic resin and sectioned at the middle and apical thirds. Root canal shaping was performed using the RaCe rotary system at 250 rpm and 1 Ncm torque. Each instrument set was used five times according to a crowndown technique in the following sequence: 40/0.10, 35/0.08, 25/0.06, 25/0.04, 25/0.02 (working length - WL), 30/0.02 (WL) and 35/0.02 (WL). Each instrument was inserted until resistance was felt and then pulled back, followed by brushing movements towards all canal walls. Each specimen was assessed by three study methods: radiographic platform, digitized image assessment and histological analysis. The radiographic platform showed lack of apical transportation. No statistically significant difference (Wilcoxon test, p>0.05) was found between the middle and apical thirds regarding instrument action on dentin walls, centering ability, area of root canal enlargement, percentage of regular dentin surfaces and debris within the root canal. It may be concluded that RaCe system is a suitable method for the preparation of curved root canals, regarding the maintenance of root canal original path, action on dentin walls, canal enlargement and removal of debris from the root canal lumen.

Dental fluorescence: Potential forensic use

In cases of identification of bones, skeletal segments or isolated bones, searching for biotypologic diagnostic data to estimate an individual's age enables comparing these data with those of missing individuals. Enamel, dentin and pulp undergo remarkable changes during an individual's life. The enamel becomes more mineralized, smoother and thinner, and deteriorates because of physiological and pathological factors. Dental pulp decreases in volume due to the deposition of secondary dentin; thus, the dentin becomes thicker with time. In natural teeth, the fluorescence phenomenon occurs in dentin and enamel and changes in those tissues may alter the expression of the natural tooth color. The aim of this study was to assess the correlation between age and teeth fluorescence for individuals from different age groups. The sample consisted of 66 randomly selected Brazilians of both genders aged 7-63 years old. They were divided into 6 groups: Group 1 - aged 7-12 years, Group 2 - aged 13-20 years, Group 3 - aged 21-30 years, Group 4 - aged 31-40 years, Group 5 - aged 41-50 years and Group 6 - aged between 51 and 63 years. Upper right or left central incisors were used for the study. Restored and aesthetic rehabilitated teeth were excluded from the sample. The measurement of tooth fluorescence was carried out via computer analysis of digital images using the software ScanWhite DMC/Darwin Systems - Brazil. It was observed that dental fluorescence decreases when comparing the age groups 21-30, 31-40, 41-50 and 51-63 years. The results also showed that there is a statistically significant difference between the groups 41-50 years and 21-30 years (p=. 0.005) and also among the group 51-63 years and all other groups (p< 0.005). It can be concluded that dental fluorescence is correlated with age and has a similar and stable behavior from 7 to 20 years of age. It reaches its maximum expected value at the age of 26.5 years and thereafter decreases. © 2013 Elsevier B.V.

Toxic effects of daily applications of 10% carbamide peroxide on odontoblast-like MDPC-23 cells

Background. Tooth bleaching has been widely studied, mainly due to the possible undesirable effects that can be caused by this esthetic procedure. The cytotoxicity of the bleaching agents and its components to pulp cells has been demonstrated in several researches. The aim of this study was to evaluate the toxic effects of successive applications of 10% carbamide peroxide (CP) gel on odontoblast-like cells. Materials and methods. Enamel-dentin discs obtained from bovine incisors were adapted to artificial pulp chambers (APCs). The groups were formed as follows: G1: Without treatment (control group); G2: 10% carbamide peroxide, CP (five applications/one per day); G3: 10% CP (one unique application); and G4: 35% hydrogen peroxide, HP (three applications of 15 min each). After treatment, cell metabolism (MTT), alkaline phosphatase (ALP) activity and plasma membrane damage (flow cytometry) were analyzed. Results. Reductions in cell metabolism and alkaline phosphatase activity along with severe damage of the cytoplasmic membrane were noted in G2. In G3, no damage was observed, compared to the control group. Intermediary values of toxicity were obtained after 35% HP application. Conclusion. It can be concluded that one application of 10% CP did not cause toxic effects in odontoblast-like cells, but the successive application of this product promoted severe cytotoxic effects. The daily application of the bleaching agents, such as used in the at-home bleaching technique, can increase the damages caused by this treatment to the dental pulp cells. © 2013 Informa Healthcare.

Influence of artificial aging in marginal adaptation of mixed class V cavities

The aim of this study was to investigate whether the artificial aging by thermal cycling had influenced the marginal adaptation of class V restorations with/without chlorhexidine application in the bond process. Twelve intact human third molars were used. Class V cavity preparations were performed on the buccal surface and the teeth received 35% phosphoric acid-etching procedure (Ultradent Products Inc., South Jordan, Utah, USA). Subsequently, the samples were divided in two groups: Untreated acid-etched dentin and chlorhexidine application as an adjunct in the bond process. The adhesive Single Bond 2 (3M ESPE, St. Paul, MN, USA) was used after 2% chlorhexidine application, and the restorations were performed with FiltekTM Z350 XT (3M ESPE) composite resin. The specimens were submitted to artificial aging by thermal cycling with 3,000 cycles. Analyzes were performed on scanning electron microscopy using replicas of marginal adaptation in percentage of continuous margin before and after the artificial aging. The data were analyzed by paired test and the results showed statistically significant differences in the percentage of continuous margin with/without chlorhexidine treatment before and after thermal cycling. This study concluded that the artificial aging by thermal cycling influenced the marginal adaptation of mixed class V composite restorations.

Resposta pulpar de dentes de ratos após tratamento capeador direto com sistema adesivo monocomponente ou autocondicionante

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Tempo de condicionamento da dentina hígida e afetada por cárie de dentes decíduos e permanentes: efeito na desmineralização do substrato, na produção e na resistência da união resina-dentina

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo histomorfométrico de incisivos de ratos submetidos a diferentes níveis de luxação extrusiva e subluxação

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influência in vitro da clorexidina e do chá verde na longevidade de união adesiva resina composta – dentina

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito da ativação química do gel de peróxido de carbamida a 10% no clareamento dental

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo das propriedades mecânicas da interface adesiva criada por sistemas adesivos convencional e autocondicionante, associados ou não ao laser Nd:YAG, utilizando a técnica da nanoindentação

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da resistência de união em dentina submetida ao desafio erosivo: adesão ao substrato tratado com CPP-ACP e irradiado ou não com laser Nd:YAG

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito da utilização de substâncias inibidoras de metaloproteinases e de tipos de envelhecimento na resistência de união entre dentina e resina composta

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da resistência de união entre dentina preparada por laser e um sistema adesivo a base de silorano, variando a técnica de aplicação e umidade do substrato

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)