José Eduardo de Oliveira Lima

Effect of plaque accumulation and salivary factors on enamel demineralization and plaque composition in situ

This study evaluated the effect of some plaque and salivary factors on caries progression in situ. The salivary secretion rate, buffering capacity and mutans streptococci counts from 13 volunteers were determined. For three distinct periods of time, 4, 7 and 10 days, each of them wore a palatal appliance containing 4 bovine enamel blocks. They used a non-fluoridated dentifrice during the experiment and a 20% sucrose solution was dripped onto the blocks 10 times a day. Mutans streptococci (MS), calcium (Ca), and insoluble polysaccharide (IP) were quantified in the dental plaque formed on the enamel blocks, after each period. Enamel demineralization was assessed by surface microhardness, and the percentage of surface microhardness change (%SMC) in relation to the baseline values was calculated. Enamel demineralization occurred after each period of plaque accumulation (p < 0.05), and the %SMC increased with time (from 13.8 to 48.3%). The concentrations of Ca and IP in plaque were not statistically different among the experimental times, but significant correlations were found between these concentrations and %SMC. Neither the salivary factors assessed initially nor mutans streptococci in plaque presented statistically significant correlations to %SMC. The results suggest that enamel demineralization is time-dependent and is more related to the composition of the biofilm formed than to the salivary factors studied.

Clinical and microbiological evaluation of the periodontal status of children with unilateral complete cleft lip and palate.

Objective To compare periodontal conditions in children with and without cleft. Design Clinical examinations and microbiological analysis of 57 selected children, including 30 with unilateral complete cleft lip and palate (experimental group) and 27 without clefts (control group). Setting Hospital of Rehabilitation of Craniofacial Anomalies (HRCA) in Bauru, Sao Paulo, Brazil. Patients, Participants All children examined were healthy and between the ages of 5 and 6 years. Results The mean plaque index (PI) in the experimental group was higher (1.82 ± 0.3) than in the control group (1.63 ± 0.38), although this difference was not statistically significant. The mean gingival index (GI) in the experimental group (1.82 ± 0.38) was found to be significantly higher (p < .05) than that of the control group (0.79 ± 0.33). The cleft area in the experimental group, with a mean PI of 2.04 ± 0.58 and mean GI of 1.11 ± 0.26, compared with the posterior area, with a mean PI of 1.74 ± 0.37 and mean GI of 1.04 ± 0.26, showed a statistically significant difference only in the PI. Most of the children in both experimental and control groups presented a moderate PI degree (73.33% and 81.48%, respectively) and a high prevalence of mild gingivitis (53.33% and 70.37%, respectively). Analysis of the organisms showed that Prevotella nigrescens was detected in 16.67% of the experimental group and 11.11% of the control, whereas Porphyromonas gingivalis and Treponema denticola were not detected. Conclusion Children with clefts showed greater gingival inflammation, despite the same amount of plaque and prevalence of microorganisms.

Chronology and Sequence of Eruption of the Permanent Teeth in Patients With Complete Unilateral Cleft Lip and Palate

Objective To establish the chronology and sequence of eruption of the permanent teeth in subjects with complete unilateral cleft lip and palate. Design Cross-sectional. Data on children presenting complete cleft lip and palate were evaluated. Setting The study was carried out at the Hospital for Rehabilitation of Craniofacial Anomalies, Bauru, Sao Paulo, Brazil. Sample The sample comprised 477 patients with complete unilateral cleft lip and palate, aged 5 to 14 years. Of these patients, 166 were girls and 311 were boys. Results The girls presented, for all maxillary and mandibular teeth, a smaller mean age of eruption than the boys. The maxillary lateral incisor and cuspid adjacent to the cleft presented significantly higher mean ages of eruption than their homologous teeth on the noncleft side.

Anesthetic technique for inferior alveolar nerve block: a new approach

Background Effective pain control in Dentistry may be achieved by local anesthetic techniques. The success of the anesthetic technique in mandibular structures depends on the proximity of the needle tip to the mandibular foramen at the moment of anesthetic injection into the pterygomandibular region. Two techniques are available to reach the inferior alveolar nerve where it enters the mandibular canal, namely indirect and direct; these techniques differ in the number of movements required. Data demonstrate that the indirect technique is considered ineffective in 15% of cases and the direct technique in 1329% of cases. Objective Objective: The aim of this study was to describe an alternative technique for inferior alveolar nerve block using several anatomical points for reference, simplifying the procedure and enabling greater success and a more rapid learning curve. Materials and Methods A total of 193 mandibles (146 with permanent dentition and 47 with primary dentition) from dry skulls were used to establish a relationship between the teeth and the mandibular foramen. By using two wires, the first passing through the mesiobuccal groove and middle point of the mesial slope of the distolingual cusp of the primary second molar or permanent first molar (right side), and the second following the oclusal plane (left side), a line can be achieved whose projection coincides with the left mandibular foramen. Results The obtained data showed correlation in 82.88% of cases using the permanent first molar, and in 93.62% of cases using the primary second molar. Conclusion This method is potentially effective for inferior alveolar nerve block, especially in Pediatric Dentistry.

Evaluation of superficial microhardness in dental enamel with different eruptive ages

This study evaluated the superficial microhardness of enamel in teeth at different posteruptive ages (before eruption in the oral cavity, 2-3 years after eruption, 4-10 years after eruption and more than 10 years after eruption). The study sample was composed of 134 specimens of human enamel. One fragment of each tooth was obtained from the flattest central portion of the crown to produce specimens with 3 x 3 mm. The enamel blocks were minimally flattened out and polished in order to obtain a flat surface parallel to the base, which is fundamental for microhardness testing. Microhardness was measured with a microhardness tester and a Knoop diamond indenter, under a static load of 25 g applied for 5 seconds. Comparison between the superficial microhardness obtained for the different groups was performed by analysis of Students t test. The results demonstrated that superficial microhardness values have a tendency to increase over the years, with statistically significant difference only between unerupted enamel and that with more than 10 years after eruption. According to the present conditions and methodology, it was concluded that there were differences between the superficial micro-hardness of specimens at different eruptive ages, revealing an increasing mineralization. However, this difference was significant only between unerupted specimens and those with more than 10 years after eruption.

Efeito da profilaxia profissional com jato de bicarbonato de sódio sobre a microbiota cariogênica

Avaliou-se o efeito da profilaxia dentaria profissional com o jato de bicarbonato de sodio na contagem salivar de estreptococos do grupo mutans e de lactobacilos em 32 criancas entre 7-10 anos. Coletou-se saliva total estimulada antes e 60 minutos apos o procedimento, e decorridos 30 dias, sendo o numero de UFC/mL saliva detectado atraves do sistema Caritest. Constatou-se uma reducao imediata, estatisticamente significativa, nos niveis salivares de ambos os microrganismos, sendo de 50% para estreptococos do grupo mutans e de 27% para lactobacilos. Para os estreptococos do grupo mutans, esta reducao persistiu pelo periodo de 30 dias, o mesmo nao ocorrendo para os lactobacilos, que retornaram aos seus valores iniciais.

Modeling of a Low Cost Laser Scanner Sensor

A laser scanner is a popular sensor widely used in industry and mobile robots applications that measures the distance to the sensor on a slice of the plan. This sensor can be used in mobile robots localization task.

Modeling and Simulation of the EMG30 Geared Motor with Encoder Resorting to SimTwo: The Official Robot@Factory Simulator

This paper describes the EMG30 mechanical and electrical modeling and its simulation resorting to SimTwo (Robot@Factory mobile robot competition official simulator). It is described the developed setup applied to obtain the experimental data that was used to estimate the actuator parameters. It was obtained an electro-mechanical dynamical model that describes the motor, its gear box, and the encoder. The motivation to model and simulate the EMG30 is the fact that it is an actuator worldwide popular in the mobile robotics domain, being a low cost 12v motor equipped with encoders and a 30:1 reduction gearbox. The Goal of this work is to provide more realism and new features to the Robot@Factory official simulator, allowing participating teams to produce and validate different robot prototypes and its software, reducing considerably the development time.

In vitro evaluation of the marginal microleakage of class II amalgam restoration associated with dentin adhesive

A microinfiltracao marginal de restauracoes de amalgama classe II (Dispersalloy), associada ao verniz convencional (Copalite) e a dois adesivos dentinarios (Scotchbond Multi-uso Plus e Multi Bond Alpha), foi avaliada e comparada in vitro atraves de dois metodos: escores e medidas lineares. Foram utilizados 45 pre-molares higidos que receberam duas cavidades independentes M e D. Apos a restauracao, foram submetidos a termociclagem e armazenados em uma solucao de fucsina basica a 0,5% durante 24 horas. A analise da infiltracao do corante permitiu concluir que nenhum dos tres sistemas restauradores foi capaz de eliminar a microinfiltracao marginal. No entanto, ela foi menor e estatisticamente significante para as restauracoes associadas aos adesivos dentinarios, quando comparadas aquelas com o verniz cavitario. O metodo das medidas lineares foi mais sensivel do que o de escores.

Airpolishing effect on bovine enamel and the posterior remineralizing effect of saliva. An in vitro study.

OBJETIVO: A finalidade do trabalho foi avaliar as alteracoes da microdureza e o desgaste provocado pelo jato de bicarbonato de sodio em esmalte bovino e o posterior efeito remineralizador da saliva artificial. METODOS: Utilizaram-se 15 especimes de esmalte (4,0mm x 4,0mm) que constituiram os grupos: sem tratamento (MI); tratamento com jato de bicarbonato de sodio (MII e DI); tratamento com jato de bicarbonato de sodio e imersao em saliva artificial por uma hora (MIII e DII), 24 horas (MIV e DIII) e sete dias (MV e DIV). Foram realizados testes de microdureza com um microdurometro nos grupos M e testes de desgaste com um rugosimetro nos grupos D. RESULTADOS: Os dados foram avaliados pela Analise de Variância a um criterio e pelo Teste de Tukey. O valor das medias da microdureza, em KHN, nos grupos MI, MII, MIII, MIV e MV foram 359,80; 335,46; 369,20; 377,73 e 341,86; respectivamente, enquanto que os valores medios, em µm, do desgaste para o grupo DI, DII, DIII e DIV foram 0,564; 0,519; 0,441 e 0,428, respectivamente. CONCLUSOES: o jato de bicarbonato de sodio causou desgaste e diminuicao da microdureza superficial; a saliva promoveu o retorno da microdureza superficial a condicao inicial e reduziu o desgaste; o efeito reparador da saliva sobre as alteracoes na microdureza superficial ja ocorreu com uma hora de tratamento, nao havendo diferenca estatisticamente significante do efeito obtido com 24 horas; o melhor efeito reparador da saliva sobre o desgaste ocorreu com 24 horas de tratamento.Purpose: The aim of the present study was to evaluate the alterations of surface microhardness and wear caused by the sodium bicarbonate jet on bovine enamel and the further remineralizing effect of artificial saliva. Methods: Fifteen enamel samples (4,0mm × 4,0mm) were used, which constituted the groups: no treatment (MI); treatment with sodium bicarbonate jet (MII and DI); treatment with sodium bicarbonate jet and immersion in saliva for one hour (MIII and DII), 24 hours (MIV and DIII) and 7 days (MV and DIV). Microhardness tests were carried out using a microdurometer in groups M and wear tests by a rugosimeter in groups D. The data were assessed by the one criterion variance analysis and Tukey test. Results: The mean value of microhardness, in KHN, in groups MI, MII, MIII, MIV and MV were 359,80; 335,46; 369,20; 377,73 and 341,86, respectively, whereas the mean values in μm, of wear for group DI, DII, DIII and DIV were 0,564; 0,519; 0,441 and 0,428, respectively. Conclusions: The sodium bicarbonate jet caused a wear and a reduction in microhardness on the enamel surface; saliva promoted the recovery of initial condition surface microhardness and reduced the wear; the repairing effect of saliva on the surface microhardness alterations occurred within one hour of treatment, having no significant statistical difference from the effect obtained in 24 hours; the best saliva repairing effect on the wear occurred with treatment of 24 hours.