34 research outputs found

    Influence of age, central corneal thickness, and quality score on dynamic contour tonometry

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    Aims To compare the IOP measurements obtained with dynamic contour tonometry (DCT) and Goldmann applanation tonometry (GAT), and to analyse the influence of central corneal thickness (CCT) and age on both measurements, and the influence of the quality score on DCT readings. Methods A total of 500 healthy subjects with no prior history of glaucoma or ocular hypertension (age: 7-86 years) were consecutively recruited. GAT, DCT, and CCT measurements were obtained from both eyes of each individual, in this order, by three observers. The mean of five CCT measurements was used for analysis. DCT measurements were accepted when quality scores varied between 1 (higher quality) and 3 (lower quality). Results Mean DCT measurements were 3.2 mmHg higher than GAT readings. CCT values varied between 449 and 653 mu m. IOP measured by GAT correlated strongly with CCT (r(2) = 0.28, P = <0.001), whereas DCT readings correlated poorly with CCT (r(2) = 0.01, P = 0.017). Both DCT (r(2) = <0.01, P = 0.044) and GAT (r(2) = 0.01, P = <0.001) measurements correlated poorly with age. Bland-Altmann analysis revealed disagreement between DCT and GAT readings, with 95% confidence intervals of +/- 6.7 mmHg. Quality scores for DCT measurements were 1 (n = 369, 36.9%), 2 (n = 340, 34.0%), and 3 (n = 291, 29.1%). DCT readings with quality score of 3 (18.8 +/- 3.4 mmHg) were significantly higher than those with quality scores of 1 (16.7 +/- 2.9 mmHg) and 2 (17.4 +/- 2.9 mmHg; P = <0.001). Conclusions DCT is not influenced by CCT, unlike GAT. Both DCT and GAT measurements are not influenced by age. DCT measurements with lower quality scores are associated with higher readings. Eye (2009) 23, 1364-1369; doi:10.1038/eye.2008.278; published online 12 September 20082361364136

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

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)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.71513191325Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [2009/08992-7, 2009/08992-8, 2010/00645-3]CNPq [301291/2010-1

    Intrasession, intersession, and interexaminer variabilities of retinal nerve fiber layer measurements with spectral-domain OCT

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Purpose. To evaluate the intrasession, intersession, and interexaminer variabilities of retinal nerve fiber layer measurements (RNFL) with spectral-domain optical coherence tomography (OCT). Methods. A total of 32 healthy individuals and 34 patients with chronic glaucoma underwent RNFL measurements with the Cirrus HD-OCT Model 4000 (Carl Zeiss Meditec, Dublin, CA, USA) 5 times during the same sitting by one examiner to assess intrasession variability. The same examiner performed RNFL measurements in the same patients on 5 different days to assess intersession variability. A second examiner performed RNFL measurements in the same patients to assess interexaminer variability. The coefficients of variation and intraclass correlation coefficients were obtained for the following parameters: average thickness, quadrant thickness, and Clock hour thickness measurements. Results. Intrasession variability: In patients with glaucoma, coefficients of variation ranged from 4.51% to 11.84%. Intraclass correlation coefficients ranged from 0.74 to 0.99. In healthy individuals, coefficients of variation ranged from 2.92% to 6.99%. Intraclass correlation coefficients ranged from 0.89 to 0.98. Intersession variability: In patients with glaucoma, coefficients of variation ranged from 3.68% to 10.50%. Intraclass correlation coefficients ranged from 0.82 to 0.99. In healthy individuals, coefficients of variation ranged from 3.13% to 6.92%. Intraclass correlation coefficients ranged from 0.87 to 0.99. Interexaminer variability: In patients with glaucoma, coefficients of variation ranged from 2.62% to 14.94%. Intraclass correlation coefficients ranged from 0.55 to 0.98. In healthy individuals, coefficients of variation ranged from 2.04% to 7.31%. Intraclass correlation coefficients ranged from 0.86 to 0.98. Conclusions. These findings indicate that RNFL measurements with spectral-domain OCT display excellent reproducibility, with low intrasession, intersession, and interexaminer variabilities.213264270Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [07/51281-9

    Effects of Laser Irradiation on Pulp Cells Exposed to Bleaching Agents

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The aim of this study was to evaluate the effect of low-level laser therapy (LLLT) on odontoblast-like cells exposed to a bleaching agent. Mouse dental papilla cell-23 cells were seeded in wells of 24-well plates. Eight groups were established according to the exposure to the bleaching agent and LLLT (0, 4, 10 and 15Jcm(-2)). Enamel-dentin disks were adapted to artificial pulp chambers, which were individually placed in wells containing Dulbecco's modified Eagle's medium (DMEM). A bleaching agent (35% hydrogen peroxide [BA35%HP]) was applied on enamel (15min) to obtain the extracts (DMEM+BA35%HP components diffused through enamel/dentin disks). The extracts were applied (1h) to the cells, and then subjected to LLLT. Cell viability (Methyl tetrazolium assay), alkaline phosphatase (ALP) activity, as well as gene expression of ALP, fibronectin (FN) and type I collagen, were evaluated. The bleaching procedures reduced the cell viability, ALP activity and gene expression of dentin proteins. Laser irradiation did not modulate the cell response; except for FN, as LLLT decreased the gene expression of this protein by the cells exposed to the BA35%HP. It can be concluded that BA35%HP decreased the activities of odontoblasts that were not recovered by the irradiation of the damaged cells with low-level laser parameters tested.901201206Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [2009/08992-7-8, 2010/00645-3]CNPq [301291/2010-1
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