Biomimetic calcium phosphate coating on Ti-7.5Mo alloy for dental application

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

Influence of apical patency and filling material on healing process of dogs' teeth with vital pulp after root canal therapy

Foi propósito deste trabalho observar o processo de reparo de dentes de cães após obturação dos canais com dois cimentos diferentes, fazendo ou não a patência apical. Após uma sobreinstrumentação, os canais receberam um curativo de uma solução de corticosteróide-antibiótico por 7 dias, com o objetivo de obter invaginação de tecido conjuntivo para dentro dos canais. Após esse período, esse tecido foi totalmente removido em metade dos casos (grupos com patência apical) e preservados no restante dos casos (grupos sem patência apical). Os canais foram obturados pela técnica da condensação lateral empregando um cimento a base de hidróxido de cálcio (Sealer Plus) ou um cimento de Grossman (Fill Canal). Os animais foram sacrificados por overdose anestésica 60 dias após o tratamento endodôntico e as peças anatômicas foram obtidas e preparadas para análise histológica. Os dados obtidos foram analisados com base em diversos parâmetros histomorfológicos. Os resultados foram melhores nos grupos sem patência apical (p=0,01) do que nos grupos com patência. Dentre os cimentos estudados, os melhores resultados foram observados com o cimento Sealer Plus (p=0,01). em conclusão, tanto a patência apical (presença ou ausência) quanto o tipo de material obturador de canal influíram no processo de reparo apical de dentes de cães com polpas vitais após tratamento endodôntico. O emprego de um cimento a base de hidróxido de cálcio em dentes sem patência apical promoveu os melhores resultados, dentre as condições experimentais propostas.

Cytotoxicity of resin-based light-cured liners

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The influence of short-term diabetes mellitus and insulin therapy on alveolar bone loss in rats

Background: It is well known that the multiple direct and indirect consequences of hyperglycemia in diabetic individuals have been linked to a number of abnormal host effector mechanisms that could lead to an increased risk of developing periodontal disease.Objective: the aim of this study was to investigate the effect of short-term experimental diabetes and insulin therapy on the severity of alveolar bone loss in rats, and the effect of experimental periodontitis on glycemic control.Methods: Seventy-two male Wistar rats were divided into four groups: group I animals were submitted to dental ligature around lower right first molars (ligated); group II consisted of streptozotocin (STZ)-diabetic, ligated rats; group III represented STZ-diabetic, unligated rats; and group IV consisted of insulin-treated (6 U/day), STZ-diabetic, ligated rats. Blood glucose of all diabetic rats was monitored at regular intervals. Standardized digital radiographs were taken after killing at 7, 15 and 30 days to measure the amount of bone loss about the mesial root surface of the first molar tooth in each rat.Results: No significant (p < 0.05) changes in plasma glucose levels of insulin-treated diabetic rats were found among the different examinations after the beginning of insulin therapy. Rats from group II showed significantly greater increases in mean plasma glucose levels at 15 and 30 days after ligature placement compared with rats from group III (p < 0.05). Furthermore, in spite of the significant alveolar bone loss progression that was observed in groups I, II and IV (p < 0.00001; two-way ANOVA), no significant differences among these groups regarding the severity of bone loss (p = 0.77) and no significant interaction between treatment group and time (p = 0.81) were found.Conclusions: Within the limits of this study, it can be suggested that the severity of periodontal disease was not affected by short-term diabetes, and that experimental periodontitis increased blood glucose levels in uncontrolled diabetic rats.

Mineral Trioxide Aggregate-based Endodontic Sealer Stimulates Hydroxyapatite Nucleation in Human Osteoblast-like Cell Culture

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Comparison of Biomaterial Implants in the Dental Socket: Histological Analysis in Dogs

Background:Bone graft procedures have been used commonly in buco-maxillo-facial surgery. For this reason, many researchers have evaluated the bone substitutes.Purpose:The present study evaluated soft and hard tissue reactions to two different hydroxyapatites HAs (synthetic HA and natural HA) and bioactive glass implanted into the sockets immediately after extraction.Materials and Methods:First and third upper and lower premolars, on both sides, were extracted from six female dogs. The alveolar sockets were randomly assigned to four groups: Group 1 - control (unfilled), Group 2 - filled with synthetic hydroxyapatite, Group 3 - filled with bovine bone mineral (natural HA), and Group 4 - filled with bioactive glass. The animals were euthanized at 4 weeks (n = 2), 8 weeks (n = 2), and 28 weeks (n = 2) after extraction. The mandible and maxilla of each animal were removed for histological analysis to determine soft tissue reactions, newly formed bone, bone characteristics, and presence or absence of implanted materials.Results:Most particles of synthetic hydroxyapatite had bone formation on their surface, although some particles showed a layer of fibrous connective tissue. The bovine bone mineral group exhibited particles partially replaced with bone formation. The bioactive glass group showed particles with a thin layer of calcified tissue, but was absent in some specimens, suggesting complete resorption.Conclusion:All biomaterials had similar behavior. Bovine bone mineral, compared to synthetic hydroxyapatite and bioactive glass, showed a larger number of particles covered with osseous tissue. All biomaterials interfered with the socket repair process.

Effect of selective cyclooxygenase-2 inhibition on the development of ligature-induced periodontitis in rats

Background: the purpose of this study was to evaluate the effect of a selective cyclooxygenase-2 inhibitor on the progression of alveolar bone loss in an experimental periodontitis model in rats.Methods: One hundred eighty (180) Wistar rats were separated into 3 experimental groups. Cotton ligatures were placed at the gingival margin level of lower right first molars. The rats were randomly assigned to one of the following groups that received: a daily oral dose of 10 mg/kg body weight of celecoxib (Ce1); 20 mg/kg body weight of celecoxib (Ce2); or 10 ml/kg of saline solution (C). Serum levels of celecoxib and white blood cell count were determined. Standardized digital radiographs were taken after sacrifice at 3, 5, 10, 18, and 30 days to measure the amount of bone loss around the mesial root surface of the first molar tooth in each rat.Results: Two-way analysis of variance (ANOVA) indicated that groups treated with celecoxib had significantly less bone loss compared to controls (P <0.0001) and that there was a significant interaction between treatment with celecoxib and time (P <0.03). Post-hoc comparisons showed that in both groups treated with celecoxib, the bone loss became significant only after 10 days of ligature placement, while in the control group it was already significant after 5 days. However, differences in mean bone loss between control and Ce1 were significant only at 18 days and, between control and Ce2, at 5 and 18 days. There was no significant difference in bone loss among experimental groups at the end of the experimental period.Conclusion: These data provide evidence that systemic therapy with celecoxib can modify the progression of experimentally induced periodontitis in rats.

Microwave Disinfection of Complete Dentures Contaminated In Vitro with Selected Bacteria

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

Enterococcus faecalis leakage of root canal sealers: an ex vivo study

The aim of this ex vivo study was to evaluate bacterial penetration after filling root canals using 3 different techniques. Three experimental groups of 25 teeth each, obturated with lateral-warm-vertical condensation of gutta-percha, Microseal technique and EndoREZ (R) system, respectively, were tested in a split chamber model system using Enterococcus faecalis and monitored for 180 days to determine bacterial penetration. A statistical analysis was performed using the Kaplan-Meier method. Median survival time was 25 days for Microseal system, 41 for lateral-warm-vertical condensation and 81 for EndoREZ (R). Significant differences were demonstrated between Microseal and EndoREZ (R) (p<0.001) and between Microseal and lateral-warm-vertical condensation technique (p<0.05). No statistically significant differences were observed between EndoREZ (R) and lateral-warm-vertical condensation. After 180 days of assessment, 20% of the EndoREZ (R) samples resisted bacterial penetration and furthermore, the EndoREZ (R) system has the potential to be a filler system compatible with other currently used systems.

Solarização em microcosmo: efeito de materiais vegetais na sobrevivência de fitopatógenos de solo e na produção de voláteis

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

O ensino da digestão-nutrição na era das refeições rápidas e do culto ao corpo

Mudanças notáveis nos hábitos alimentares, acompanhadas de práticas fisioculturistas intensas, são a tônica dos dias atuais, com registros de carências nutricionais e de obesidade bastante preocupantes, do ponto de vista da saúde pública, entre crianças, jovens e adultos. Mas o que conhecem as crianças e os adolescentes sobre o processo de digestão-nutrição, os conceitos básicos envolvidos e as condutas alimentares adequadas à boa saúde humana? Como é desenvolvido esse tema nas escolas públicas e particulares de ensino? Tais questionamentos desencadearam um estudo sobre a natureza das práticas desenvolvidas por professores de ciências e biologia e o conhecimento apresentado por alunos de escolas públicas e particulares. Os resultados revelaram inadequação no tratamento metodológico de ensino do processo de digestão e conceitos envolvidos nesse tema, que levam os alunos ao desinteresse e a manterem praticamente inalterados os conhecimentos ordinários que possuem. O processo de digestão e nutrição, bem como suas implicações para a saúde, configuraram-se como fenômenos desvinculados do aluno, à semelhança do que observamos nos livros didáticos por eles utilizados. A dinâmica das inter-relações alimentares entre seres vivos são superficialmente consideradas em ecologia e passam ao largo das adaptações comportamentais, morfológicas e fisiológicas envolvidas. Considerando esses resultados, propõe-se conteúdo baseado em abordagem ecológica, voltado para determinadas atividades experimentais, jogos e interações coevolutivas de seres vivos - aspectos biológicos e sociais, para o despertar de posturas reflexivas e críticas diante das transformações sociais em curso e de nossas necessidades biológicas no que se refere à alimentação e saúde.

Conditioning of stress in Nile tilapia

A Pavlovian conditioning paradigm was used to induce a connection between a conditioned stimulus, light (CS), associated with an unconditioned stimulus, confinement (US) in Nile tilapia Oreochromis niloticus, which resulted in a conditioned endocrine response (CR) to the CS alone manifested as an increase in plasma cortisol. Individual isolated Nile tilapia were submitted for 10 days to the conditioning treatment consisting of turning on a light (CS) for I min with subsequent 30 min confinement (US). on the 10th day of the experiment, plasma cortisol was not increased when fish were subjected to no handling at all, or only light, or even a daily stressor for the 9 days. on the other hand, at the 10th day cortisol was significantly increased only when light was presented either with or without pairing with the stressor. These results confirmed that the cue, light (CS), was not stressful in itself, but when given as the CS in the absence of the US post conditioning the hypothalamus-pituitary-interrenal axis was activated. Therefore, it was concluded that memory of a previous experience with a stressor can be recalled by a conditioned stimulus and induce stress, which is the first demonstration of a memory-induced stress in fishes. (C) 2004 the Fisheries Society of the British Isles.

Th1/Th2 cytokines' expression and production by propolis-treated mice

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

Effect of a previous high intensity running exercise on isokinetic muscular strength in individuals with different training backgrounds

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

Determination of the lactate threshold and maximal blood lactate steady state intensity in aged rats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)