60 resultados para indirect and composite estimators


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To examine whether polymer based coronary stents eluting sirolimus or paclitaxel are equally effective in patients with and without diabetes.

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Three different fissure preparation procedures were tested and compared to the non-invasive approach using a conventional unfilled sealant and a flowable composite. Eighty permanent molars were selected and divided into 4 groups of 20 teeth each. All the teeth were split into 2 halves, and the exposed fissures were photographed under a microscope (35x) before and after being prepared using the following methods: (I) Er:YAG laser (KEY Laser, KaVo) 600 mJ pulse energy, 6 Hz; (II) diamond bur; (III) Er: YAG laser (KEY Laser, KaVo) 200 mJ pulse energy, 4 Hz; (IV) Control group: Powder jet cleaner (Prophyflex, KaVo, Germany). The pre-and postimages were superimposed in order to evaluate the amount of hard tissue removed. Ten teeth in each group were then acid etched and sealed with an unfilled sealant (Delton opaque, Dentsply), while the remaining 10 teeth were acid etched, primed and bonded (Prime ; Bond NT, Dentsply) and sealed with a flowable composite (X-flow, DeTrey, Dentsply). Material penetration and microleakage were evaluated after thermocycling (5000 cycles) and staining with methylene blue 5%. ANOVA and Mann-Whitney tests were applied for statistical analysis. The laser 600 mJ and bur eliminated the greatest amount of hard tissue. The control teeth presented the least microleakage when sealed with Delton or X-flow. A correlation between material penetration and microleakage could not be statistically confirmed. Mechanical preparation prior to fissure sealing did not enhance the final performance of the sealant.

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A laboratory study was performed to assess the influence of beveling the margins of cavities and the effects on marginal adaptation of the application of ultrasound during setting and initial light curing. After minimal access cavities had been prepared with an 80 microm diamond bur, 80 box-only Class II cavities were prepared mesially and distally in 40 extracted human molars using four different oscillating diamond coated instruments: (A) a U-shaped PCS insert as the non-beveled control (EMS), (B) Bevelshape (Intensiv), (C) SonicSys (KaVo) and (D) SuperPrep (KaVo). In groups B-D, the time taken for additional bevel finishing was measured. The cavities were filled with a hybrid composite material in three increments. Ultrasound was also applied to one cavity per tooth before and during initial light curing (10 seconds). The specimens were subjected to thermomechanical stress in a computer-controlled masticator device. Marginal quality was assessed by scanning electron microscopy and the results were compared statistically. The additional time required for finishing was B > D > C (p < or = 0.05). In all groups, thermomechanical loading resulted in a decrease in marginal quality. Beveling resulted in higher values for "continuous" margins compared with that of the unbeveled controls. The latter showed better marginal quality at the axial walls when ultrasound was used. Beveling seems essential for good marginal adaptation but requires more preparation time. The use of ultrasonic vibrations may improve the marginal quality of unbeveled fillings and warrants further investigation.

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BACKGROUND: Genetically transmitted traits such as cytokine gene polymorphisms may accentuate the host inflammatory response to the bacterial challenge and influence susceptibility to periodontitis. OBJECTIVE: To systematically review the evidence of an association between the interleukin-1 (IL-1) composite genotype, i.e. presence of the allele 2 in the gene clusters IL-1A-889 and in IL-1B +3953, and periodontitis progression and/or treatment outcomes. Material and Methods: Based on the focused question, a search was conducted for longitudinal clinical trials comparing progression of periodontitis and/or treatment outcomes in IL-1 genotype-positive (carrying allele 2) and IL-1 genotype-negative (not carrying allele 2) subjects. A search in the National Library of Medicine computerized bibliographic database MEDLINE and a manual search were performed. Selection of publications, extraction of data and validity assessment were made independently by two reviewers. RESULTS: The search provided 122 titles of which 11 longitudinal publications were included. The heterogeneity of the data prevented the performance of a meta-analysis. While findings from some publications rejected a possible role of IL-1 composite genotype on progression of periodontitis after various therapies, other reported a prognostic value for disease progression of the positive IL-1 genotype status. When assessed on a multivariate risk assessment model, several publications concluded that the assessment of the IL-1 composite genotype in conjunction with other covariates (e.g. smoking and presence of specific bacteria) may provide additional information on disease progression. The small sample size of the available publications, however, requires caution in the interpretation of the results. CONCLUSION: Based on these findings, (i) there is insufficient evidence to establish if a positive IL-1 genotype status contributes to progression of periodontitis and/or treatment outcomes. Therefore, (ii) results obtained with commercially available tests should be interpreted with caution.

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The aim of this study was to evaluate the effectiveness of the indirect instruction and the influence of the periodic reinforcement on the plaque index in schoolchildren. Forty schoolchildren aged from 7 to 9 years old were selected from a public school. After determining the initial O'Leary Plaque Index all schoolchildren were submitted to a program for oral hygiene through indirect instruction -"The Smiling Robot". The schoolchildren were divided into 2 groups: with and without motivation reinforcement. The index plaque exam was performed in both groups after 30, 60 and 90 days of the educational program. Comparing the groups, the plaque index decreasing could be observed in the group with reinforcement with statistically significant difference. For the group with reinforcement, statistically significant difference among the evaluations was found. For the group without reinforcement, significant decrease in the plaque index was found after 30 days when compared to the first, third and fourth evaluations. The indirect instruction with "The Smiling Robot "promoted a positive initial impact on the decrease of plaque index in the schoolchildren. The periodic reinforcements showed more suitable results and significant reduction of the plaque index in the course of the evaluations.

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Plant species richness of permanent grasslands has often been found to be significantly associated with productivity. Concentrations of nutrients in biomass can give further insight into these productivity- plant species richness relationships, e.g. by reflecting land use or soil characteristics. However, the consistency of such relationships across different regions has rarely been taken into account, which might significantly compromise our potential for generalization. We recorded plant species richness and measured above-ground biomass and concentrations of nutrients in biomass in 295 grasslands in three regions in Germany that differ in soil and climatic conditions. Structural equation modelling revealed that nutrient concentrations were mostly indirectly associated with plant species richness via biomass production. However, negative associations between the concentrations of different nutrients and biomass and plant species richness differed considerably among regions. While in two regions, more than 40% of the variation in plant species richness could be attributed to variation in biomass, K, P, and to some degree also N concentrations, in the third region only 15% of the variation could be explained in this way. Generally, highest plant species richness was recorded in grasslands where N and P were co-limiting plant growth, in contrast to N or K (co-) limitation. But again, this pattern was not recorded in the third region. While for two regions land-use intensity and especially the application of fertilizers are suggested to be the main drivers causing the observed negative associations with productivity, in the third region the little variance accounted for, low species richness and weak relationships implied that former intensive grassland management, ongoing mineralization of peat and fluctuating water levels in fen grasslands have overruled effects of current land-use intensity and productivity. Finally, we conclude that regional replication is of major importance for studies seeking general insights into productivity-diversity relationships.

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Uptake of eugenol from eugenol-containing temporary materials may reduce the adhesion of subsequent resin-based restorations. This study investigated the effect of duration of exposure to zinc oxide–eugenol (ZOE) cement on the quantity of eugenol retained in dentin and on the microtensile bond strength (μTBS) of the resin composite. The ZOE cement (IRM Caps) was applied onto the dentin of human molars (21 per group) for 1, 7, or 28 d. One half of each molar was used to determine the quantity of eugenol (by spectrofluorimetry) and the other half was used for μTBS testing. The ZOE-exposed dentin was treated with either OptiBond FL using phosphoric acid (H3PO4) or with Gluma Classic using ethylenediaminetetraacetic acid (EDTA) conditioning. One group without conditioning (for eugenol quantity) and two groups not exposed to ZOE (for eugenol quantity and μTBS testing) served as controls. The quantity of eugenol ranged between 0.33 and 2.9 nmol mg−1 of dentin (median values). No effect of the duration of exposure to ZOE was found. Conditioning with H3PO4 or EDTA significantly reduced the quantity of eugenol in dentin. Nevertheless, for OptiBond FL, exposure to ZOE significantly decreased the μTBS, regardless of the duration of exposure. For Gluma Classic, the μTBS decreased after exposure to ZOE for 7 and 28 d. OptiBond FL yielded a significantly higher μTBS than did Gluma Classic. Thus, ZOE should be avoided in cavities later to be restored with resin-based materials.

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OBJECTIVES To evaluate the effect of a tin-containing fluoride (Sn/F) mouth rinse on microtensile bond strength (μTBS) between resin composite and erosively demineralised dentin. MATERIALS AND METHODS Dentin of 120 human molars was erosively demineralised using a 10-day cyclic de- and remineralisation model. For 40 molars, the model comprised erosive demineralisation only; for another 40, the model included treatment with a NaF solution; and for yet another 40, the model included treatment with a Sn/F mouth rinse. In half of these molars (n = 20), the demineralised organic matrix was continuously removed by collagenase. Silicon carbide paper-ground, non-erosively demineralised molars served as control (n = 20). Subsequently, μTBS of Clearfil SE/Filtek Z250 to the dentin was measured, and failure mode was determined. Additionally, surfaces were evaluated using SEM and EDX. RESULTS Compared to the non-erosively demineralised control, erosive demineralisation resulted in significantly lower μTBS regardless of the removal of demineralised organic matrix. Treatment with NaF increased μTBS, but the level of μTBS obtained by the non-erosively demineralised control was only reached when the demineralised organic matrix had been removed. The Sn/F mouth rinse together with removal of demineralised organic matrix led to significantly higher µTBS than did the non-erosively demineralised control. The Sn/F mouth rinse yielded higher μTBS than did the NaF solution. CONCLUSIONS Treatment of erosively demineralised dentin with a NaF solution or a Sn/F mouth rinse increased the bond strength of resin composite. CLINICAL RELEVANCE Bond strength of resin composite to eroded dentin was not negatively influenced by treatment with a tin-containing fluoride mouth rinse.

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OBJECTIVE: To evaluate the agreement of blood pressure measurements and hypertension scores obtained by use of 3 indirect arterial blood pressure measurement devices in hospitalized dogs. Design-Diagnostic test evaluation. ANIMALS: 29 client-owned dogs. PROCEDURES: 5 to 7 consecutive blood pressure readings were obtained from each dog on each of 3 occasions with a Doppler ultrasonic flow detector, a standard oscillometric device (STO), and a high-definition oscillometric device (HDO). RESULTS: When the individual sets of 5 to 7 readings were evaluated, the coefficient of variation for systolic arterial blood pressure (SAP) exceeded 20% for 0% (Doppler), 11 % (STO), and 28% (HDO) of the sets of readings. After readings that exceeded a 20% coefficient of variation were discarded, repeatability was within 25 (Doppler), 37 (STO), and 39 (HDO) mm Hg for SAP. Correlation of mean values among the devices was between 0.47 and 0.63. Compared with Doppler readings, STO underestimated and HDO overestimated SAP. Limits of agreement between mean readings of any 2 devices were wide. With the hypertension scale used to score SAP, the intraclass correlation of scores was 0.48. Linear-weighted inter-rater reliability between scores was 0.40 (Doppler vs STO), 0.38 (Doppler vs HDO), and 0.29 (STO vs HDO). CONCLUSIONS AND CLINICAL RELEVANCE: Results of this study suggested that no meaningful clinical comparison can be made between blood pressure readings obtained from the same dog with different indirect blood pressure measurement devices.