Distribution of contagious and environmental mastitis agents isolated from milk samples collected from clinically health buffalo cows between brazilian dry and rainy seasons of the year

The present study was performed to evaluate the microbiological characteristics of clinically health quarters submitted to milking and also to observe the distribution of contagious and environmental agents between brazilian dry and rainy seasons of the year. During nine months 734 quarters from 37 buffalo cows were submitted monthly to udder inspection, palpation and strip cup test before milking. 734 asseptic milk samples were inoculated in 10% ovine blood agar and in MacConkey agar media, then incubated for 72 hours at 37 C. Among the 580 isolated microrganisms, 182 (31,38%) were recovered from samples collected during the rainy season and 398 (68,62%) from the dry season. In the rainy period the most prevalent agents were: bacteria from the genus Corynebacterium sp (53,30%), Staphylococcus sp (19,78%) and Rhodococcus equi (13,74%). In the dry period, the commonest ones were: Corynebacterium sp (44,97%), Staphylococcus sp (18,84%) and Micrococcus sp (9,55%). The results demonstrated that the methods used to select health quarters in brazilian dairy buffalo farms allow the transmission of contagious bacteria during both seasons of the year, maintaining agents known to cause mainly subclinical inflammatory reactions that compromise cronically the physiology and production of the mammary gland.

Changes in the stiffness of demineralized dentin following application of tooth whitening agents

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Oral health education in schools: promoting health agents

Purpose: The aim of this study was to verify the influence of preschool children participating in an oral health education programme on daily health practices of their families, through parent's perception. Methods: A sample of 119 parents of 5- to 6-year-old preschool children were selected. Data were collected using a structured open-closed questionnaire, self-administered. The questions focused on parents' knowledge about activities of oral health education conducted in school, the importance given by them to these activities, learning from their offspring and the presence of habit change at home. Results: In total, 63 (52.9%) parents agreed to participate. Ninety-eight per cent knew about educative and preventive activities developed at school and all of them affirmed that these activities were important, mainly because of knowledge, motivation and improvement in children's health. Ninety and half per cent of parents reported that they learned something about oral health from their children and, among these, almost half (47.8%) cited toothbrushing as the indicator for better learning. Besides this, 87.3% of participants revealed the change in oral health habits of their family members. Conclusion: Preschool children were able to transmit knowledge acquired at school to their parents that included change in oral health routine of their family members.

Evaluation of mineral trioxide aggregate and calcium hydroxide cement as pulp-capping agents in human teeth

This study evaluated the histomorphologic response of human dental pulps capped with mineral trioxide aggregate (MTA) and Ca(OH)(2) cement (CH). Pulp exposures were performed on the occlusal floor of 40 human permanent premolars. After that, the pulp was capped either with CH or MTA and restored with composite resin. After 30 and 60 days, teeth were extracted and processed for histologic exam and categorized in a histologic score system. The data were subjected to Kruskal-Wallis and Conover tests (alpha = .05). All groups performed well in terms of hard tissue bridge formation, inflammatory response, and other pulpal findings. However, a lower response of CH30 was observed for the dentin bridge formation, when compared with MTA30 and MTA60 groups. Although the pulp healing with calcium hydroxide was slower than that of MTA, both materials were successful for pulp capping in human teeth.

In vivo evaluation of the biocompatibility of three current bonding agents

The aim of this in vivo study was to evaluate the biocompatibility of three current bonding agents and calcium hydroxide cement. Sixty polyethylene tubes filled with the following materials: Group 1: Prime & Bond NT (PB - Dentsply, US; Group 2: Bond 1 (BO - Jeneric/Pentron, US); Group 3: Optibond Solo (OP - Kerr, US); and Group 4 (control): calcium hydroxide cement - Dycal (CH - Dentsply, US) were implanted into the connective tissue of 30 rats. After 15, 30 and 60 days, the implants were excised and the animals sacrificed. The biopsies were immersed in Karnovsky (pH, 7.2) fixative solution for 48 hours, and processed using routine histological technique. Six-micron-thick sections were cut and stained with hematoxilin and eosin and Masson's trichome technique. Microscopic evaluation was used to compare the connective tissue reactions caused by the experimental and control materials adjacent to the tube opening. At 15 days, the experimental and control materials triggered a moderate to intense inflammatory response which gave rise to a thick capsule adjacent to the tube opening. With time, the inflammatory reaction decreased. At 60 days, the connective tissue adjacent to the bonding agents exhibited a persistent inflammatory response mediated by macrophages and giant cells which were engulfing displaced resin components. on the other hand, for the control group (calcium hydroxide) no inflammatory response associated with a thin capsule adjacent to the material was observed even at the 30-day period. The hard-setting calcium hydroxide cement allowed complete healing and was considered more biocompatible than the bonding agents.

Biocompatibility of resin-based materials used as pulp-capping agents

Aim To evaluate and compare the response of pulps of rats capped with resin-modified glass-ionomer cement (RMGIC) or self-etching adhesive system.Methodology Class I cavities were prepared on the occlusal surface of 54 maxillary first molars of 27 rats. Pulp exposure was performed on the cavity floor. The following resin-based materials were applied as pulp-capping agents: G1, Clearfil Liner Bond 2V (CLB 2V; Kuraray Co., Japan); G2, Vitrebond (VIT; 3M/ESPE, USA). In group 3 (control group), a calcium hydroxide/saline paste (CH; Labsynth, Brazil) was used. The cavities were restored with amalgam. After 7, 30 and 60 days, the animals were sacrificed and the jaws were processed for microscopic evaluation.Results Despite the inflammatory response caused by the experimental and the control materials at 7 days, pulpal healing associated with calcified barrier formation was observed at 60 days following the pulp therapy. Both resin-based materials promoted a large zone of cell-rich fibrodentine matrix deposition on the pulp horn related to the pulp exposure site, which was larger to VIT than to CLB 2V specimens. Tertiary dentine underneath the fibrodentine matrix was deposited by a layer of elongated pulpal cells. The remaining pulpal tissue exhibited normal histological characteristics. In the control group, healing and dentine-bridge formation was observed at 30 days. Pulpal breakdown occurred only when bacterial infection occurred.Conclusion Both experimental pulp-capping agents allowed pulpal healing characterized by cell-rich fibrodentine and tertiary dentine deposition as well as calcified barrier formation.

Transdentinal protective role of sodium ascorbate against the cytopathic effects of H2O2 released from bleaching agents

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Cytotoxicity of Portland Cement with Different Radiopacifying Agents: A Cell Death Study

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influence of root-surface conditioning with acid and chelating agents on clot stabilization

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Antihypertensive responses elicited by central moxonidine in rats: Possible role of nitric oxide

In the present study, we investigated the effects of pretreatment with N-G-nitro-L-arginine methyl ester (L-NAME) (nitric oxide synthase inhibitor) injected intravenously (IV) on the hypotension, bradycardia, and vasodilation produced by moxonidine (alpha(2)-adrenergic/imidazoline receptor agonist) injected into the fourth brain ventricle (4th V) in rats submitted to acute hypertension that results from baroreflex blockade by bilateral injections of kynurenic acid (kyn, glutamatergic receptor antagonist) into the nucleus of the solitary tract (NTS) or in normotensive rats. Male Wistar rats (n = 5 to 7/group) anesthetized with IV urethane (1.0 g kg(-1) of body weight) and a-chloralose (60mg kg(-1) of body weight) were used. Bilateral injections of kyn (2.7 nmol 100 nL(-1)) into the NTS increased baseline mean arterial pressure (148 +/- 11 mm Hg, vs. control: 102 +/- 4mm Hg) and baseline heart rate (417 +/- 11 bpm, vs. control: 379 +/- 6 bpm). Moxonidine (20 nmol mu L-1) into the 4th V reduced mean arterial pressure and heart rate to similar levels in rats treated with kyn into the NTS (68 +/- 9 mm Hg and 359 +/- 7 bpm) or in control normotensive rats (66 +/- 7 mm Hg and 362 +/- 8 bpm, respectively). The pretreatment with L-NAME (2 5 mu mol kg-1, IV) attenuated the hypotension produced by moxonidine into the 4th V in rats treated with kyn (104 +/- 6 mm Hg) or in normotensive rats (95 +/- 8 mm Hg), without changing bradycardia. Moxonidine into the 4th V also reduced renal, mesenteric, and hindquarter vascular resistances in rats treated or not with kyn into the NTS and the pretreatment with L-NAME IV reduced these effects of moxonidine. Therefore, these data indicate that nitric oxide mechanisms are involved in hypotension and mesenteric, renal, and hindquarter vasodilation induced by central moxonidine in normotensive and in acute hypertensive rats.

Antimicrobial activity of disinfectant agents incorporated into type IV dental stone

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Antihypertensive effects of central ablations in spontaneously hypertensive rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Peel bond strength of resilient liner modified by the addition of antimicrobial agents to denture base acrylic resin

In order to prolong the clinical longevity of resilient denture relining materials and reduce plaque accumulation, incorporation of antimicrobial agents into these materials has been proposed. However, this addition may affect their properties. Objective: This study evaluated the effect of the addition of antimicrobial agents into one soft liner (Soft Confort, Dencril) on its peel bond strength to one denture base (QC 20, Dentsply). Material and Methods: Acrylic specimens (n=9) were made (75x10x3 mm) and stored in distilled water at 37 degrees C for 48 h. The drug powder concentrations (nystatin 500,000U - G2; nystatin 1,000,000U - G3; miconazole 125 mg - G4; miconazole 250 mg - G5; ketoconazole 100 mg - G6; ketoconazole 200 mg - G7; chlorhexidine diacetate 5% - G8; and 10% chlorhexidine diacetate - G9) were blended with the soft liner powder before the addition of the soft liner liquid. A group (G1) without any drug incorporation was used as control. Specimens (n=9) (75x10x6 mm) were plasticized according to the manufacturers' instructions and stored in distilled water at 37 degrees C for 24 h. Relined specimens were then submitted to a 180-degree peel test at a crosshead speed of 10 mm/min. Data (MPa) were analyzed by analysis of variance (alpha=0.05) and the failure modes were visually classified. Results: No significant difference was found among experimental groups (p=0.148). Cohesive failure located within the resilient material was predominantly observed in all tested groups. Conclusions: Peel bond strength between the denture base and the modified soft liner was not affected by the addition of antimicrobial agents.