Publications by authors named "Oscar Peitl Filho"

9 Publications

  • Page 1 of 1

Corrigendum to "A clinical, randomized, controlled study on the use of desensitizing agents during tooth bleaching" [J. Dent. 43 (9) (2015) 1099-1105].

J Dent 2017 07 29;62:98. Epub 2017 May 29.

Department of Dental Materials and Prosthodontics, School of Dentistry of Ribeirão Preto, University of São Paulo, 14040-904, Brazil. Electronic address:

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http://dx.doi.org/10.1016/j.jdent.2017.05.019DOI Listing
July 2017

Bioactive glass-based surfaces induce differential gene expression profiling of osteoblasts.

J Biomed Mater Res A 2017 02 21;105(2):419-423. Epub 2016 Oct 21.

Cell Culture Laboratory, School of Dentistry of Ribeirão Preto, University of São Paulo, Av do Café s/n, Ribeirão Preto, SP, 14040-904, Brazil.

The ability of Biosilicate® with two crystalline phases (BioS-2P) to drive osteoblast differentiation encourages the investigation of the cellular mechanisms involved in this process. Then, the aim of our study was to analyze the large-scale gene expression of osteoblasts grown on BioS-2P compared with Bioglass 45S5 (45S5). Osteoblasts differentiated from rat bone marrow mesenchymal stem cells were cultured under osteogenic conditions on BioS-2P, 45S5 and polystyrene (control). After 10 days, the expression of 23,794 genes was analyzed using mRNA Sequencing and the data were validated by real-time PCR. The BioS-2P exhibited 5 genes upregulated and 3 downregulated compared with 45S5. Compared with control, BioS-2P upregulated 15 and downregulated 11 genes, while 45S5 upregulated 25 and downregulated 21 genes. Eight genes were commonly upregulated and 4 downregulated by both bioactive glasses. In conclusion, our results demonstrated that bioactive glasses affect the gene expression profiling of osteoblasts. Most of the regulated genes by both BioS-2P and 45S5 are associated with the process of mineralization highlighting their osteostimulation property that is, at least in part, derived from the ability to modulate the intracellular machinery to promote osteoblast genotype expression. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 419-423, 2017.
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http://dx.doi.org/10.1002/jbm.a.35915DOI Listing
February 2017

Toxocara canis and the allergic process.

Mem Inst Oswaldo Cruz 2015 Sep;110(6):726-31

Departamento de Morfologia e Patologia, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, SP, Brasil.

The protective effect of infectious agents against allergic reactions has been thoroughly investigated. Current studies have demonstrated the ability of some helminths to modulate the immune response of infected hosts. The objective of the present study was to investigate the relationship between Toxocara canis infection and the development of an allergic response in mice immunised with ovalbumin (OVA). We determined the total and differential blood and bronchoalveolar lavage fluid cells using BALB/c mice as a model. To this end, the levels of interleukin (IL)-4, IL-5 and IL-10 and anti-OVA-IgE were measured using an ELISA. The inflammatory process in the lungs was observed using histology slides stained with haematoxylin and eosin. The results showed an increase in the total number of leukocytes and eosinophils in the blood of infected and immunised animals at 18 days after infection. We observed a slight lymphocytic inflammatory infiltrate in the portal space in all infected mice. Anti-OVA-IgE levels were detected in smaller proportions in the plasma of immunised and infected mice compared with mice that were only infected. Therefore, we concluded that T. canis potentiates inflammation in the lungs in response to OVA, although anti-OVA-IgE levels suggest a potential reduction of the inflammatory process through this mechanism.
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http://dx.doi.org/10.1590/0074-02760150051DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4667574PMC
September 2015

Evaluation of Crystallized Biosilicate in the Reconstruction of Calvarial Defects.

J Maxillofac Oral Surg 2015 Sep 10;14(3):659-65. Epub 2015 Mar 10.

Dentistry School of Araçatuba, Universidade Estadual Paulista (UNESP), São Paulo, Brazil.

Introduction: The objective of this study was to assess the bone repair process of crystallized Biosilicate in surgically created defects on rats' calvaria. This biomaterial was recently developed for odontological use.

Materials And Methods: We used fifteen rats (rattus norvegicus albinus, Wistar), and two 5 mm surgical defects were performed on each of them; the defects were made with trephine drill on the calvarium region prior to the biomaterial placement. Groups were divided as follows: Group 1-defect filled with clot; Group 2-defect filled with crystallized Biosilicate. After 7, 14 and 28 days the animals were killed, the parts were retrieved and slides were prepared for histological studies.

Results: Bone formation was satisfactory in all groups, with direct contact between biomaterial surface and bone and absence of infection signs. The 28 days periods showed better results, and statistically significant difference between Clot Group (90.2 %) and Biosilicate (58 %; p = 0.002) was seen, regarding presence of bone tissue on the surgical defects.

Conclusion: Our study revealed that defects filled with clot present better results on bone formation compared to crystallized Biosilicate, which is considered a biocompatible material with favorable osteoconductive properties.
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http://dx.doi.org/10.1007/s12663-015-0755-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4511902PMC
September 2015

A clinical, randomized, controlled study on the use of desensitizing agents during tooth bleaching.

J Dent 2015 09 6;43(9):1099-1105. Epub 2015 Jul 6.

Department of Dental Materials and Prosthodontics, School of Dentistry of Ribeirão Preto, University of São Paulo, 14040-904, Brazil. Electronic address:

Objectives: To evaluate the efficacy of experimental proposals of desensitizing agents during tooth bleaching.

Methods: 140 participants without tooth sensitivity (TS) received 16% carbamide peroxide (14 days-04 h each) (T1) or 35% hydrogen peroxide (single session-45 min) (T2). Participants used concomitantly (10 per group): desensitizing dentifrices (D1-experimental bioactive glass-ceramic; D2-commercial potassium nitrate; D3-commercial calcium and sodium phosphosilicate) in-home, daily and, desensitizing pastes (D4-experimental bioactive glass-ceramic; D5-experimental Bioglass type 45S5; D6-commercial calcium phosphate), in-office, immediately after the treatment and more 4 times. Participants in the control group did not use any desensitizing agent. We assessed TS with Visual Analogue Scale. Assessment point 1 was immediately after the first participant's exposure to the treatments; and points 2, 3, 4, and 5 were every 72 h along the period of the study. Two-way ANOVA (considering time and desensitizing as factors) and post-hoc Tukey test (α=0.05) analyzed the data.

Results: In the control group treated with 35% hydrogen peroxide, TS increased significantly on assessment points 1 and 2. The participants who used a 5% potassium nitrate dentifrice and in-office experimental pastes did not experience TS because of the 35% in-office bleaching treatment.

Conclusions: TS caused by 35% hydrogen peroxide in-office tooth bleaching was controlled by experimental products prepared as pastes D4-experimental bioactive glass-ceramic and D5-experimental Bioglass type 45S5, but not by D1-experimental dentifrice containing bioactive glass-ceramic.

Clinical Significance: There is no a gold standard protocol for TS caused by tooth bleaching. The study of novel desensitizing agents that can obliterate the dentinal tubules in a faster-acting and long-lasting way may help meet this clinical need.
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http://dx.doi.org/10.1016/j.jdent.2015.07.002DOI Listing
September 2015

Porous bioactive scaffolds: characterization and biological performance in a model of tibial bone defect in rats.

J Mater Sci Mater Med 2015 Feb 29;26(2):74. Epub 2015 Jan 29.

Department of Physiotherapy, Post-Graduate Program of Biotechnology, Federal University of São Carlos (UFSCar), São Carlos, SP, Brazil,

The aim of this study was to evaluate the effects of highly porous Biosilicate(®) scaffolds on bone healing in a tibial bone defect model in rats by means of histological evaluation (histopathological and immunohistochemistry analysis) of the bone callus and the systemic inflammatory response (immunoenzymatic assay). Eighty Wistar rats (12 weeks-old, weighing±300 g) were randomly divided into 2 groups (n=10 per experimental group, per time point): control group and Biosilicate® group (BG). Each group was euthanized 3, 7, 14 and 21 days post-surgery. Histological findings revealed a similar inflammatory response in both experimental groups, 3 and 7 days post-surgery. During the experimental periods (3-21 days post-surgery), it was observed that the biomaterial degradation, mainly in the periphery region, provided the development of the newly formed bone into the scaffolds. Immunohistochemistry analysis demonstrated that the Biosilicate® scaffolds stimulated cyclooxygenase-2, vascular endothelial growth factor and runt-related transcription factor 2 expression. Furthermore, in the immunoenzymatic assay, BG presented no difference in the level of tumor necrosis factor alpha in all experimental periods. Still, BG showed a higher level of interleukin 4 after 14 days post-implantation and a lower level of interleukin 10 in 21 days post-surgery. Our results demonstrated that Biosilicate® scaffolds can contribute for bone formation through a suitable architecture and by stimulating the synthesis of markers related to the bone repair.
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http://dx.doi.org/10.1007/s10856-015-5411-9DOI Listing
February 2015

Histopathological, cytotoxicity and genotoxicity evaluation of Biosilicate® glass-ceramic scaffolds.

J Biomed Mater Res A 2013 Mar 31;101(3):667-73. Epub 2012 Aug 31.

Department of Physiotherapy, Post-Graduate Program of Biotechnology, Federal University of São Carlos (UFSCar), São Carlos, SP, Brazil.

This study evaluated the biocompatibility of Biosilicate® scaffolds by means of histopathological, cytotoxicity, and genotoxicity analysis. The histopathologic analysis of the biomaterial was performed using 65 male rats, distributed into the groups: control and Biosilicate®, evaluated at 7, 15, 30, 45, and 60 days after implantation. The cytotoxicity analysis was performed by the methyl thiazolyl tetrazolium (MTT) assay, with various concentrations of extracts from the biomaterial in culture of osteoblasts and fibroblasts after 24, 72, and 120 h. The genotoxicity analysis (comet assay) was performed in osteoblasts and fibroblasts after contact with the biomaterial during 24, 72, and 96 h. In the histopathology analysis, we observed a foreign body reaction, characterized by the presence of granulation tissue after 7 days of implantation of the biomaterial, and fibrosis connective tissue and multinucleated giant cells for longer periods. In the cytotoxicity analysis, extracts from the biomaterial did not inhibit the proliferation of osteoblasts and fibroblasts, and relatively low concentrations (12.5% and 25%) stimulated the proliferation of both cell types after 72 and 120 h. The analysis of genotoxicity showed that Biosilicate® did not induce DNA damage in both lineages tested in all periods. The results showed that the Biosilicate® scaffolds present in vivo and in vitro biocompatibility.
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http://dx.doi.org/10.1002/jbm.a.34360DOI Listing
March 2013

Effects of biosilicate and bioglass 45S5 on tibial bone consolidation on rats: a biomechanical and a histological study.

J Mater Sci Mater Med 2009 Dec;20(12):2521-6

Department of Physiotherapy, Federal University of São Carlos (UFSCar), Sao Carlos, SP, Brazil.

The purpose of this study was to investigate the effects of Bioglass 45S5 and Biosilicate, on bone defects inflicted on the tibia of rats. Fifty male Wistar rats were used in this study, and divided into five groups, including a control group, to test Biosilicate and Bioglass materials of two different particle sizes (180-212 microm or 300-355 microm). All animals were sacrificed 15 days after surgery. No significant differences (P > 0.05) were found when values for Maximal load, Energy Absorption and Structural Stiffness were compared among the groups. Histopathological evaluation revealed osteogenic activity in the bone defect for the control group. Nevertheless, it seems that the amount of fully formed bone was higher in specimens treated with Biosilicate (granulometry 300-355 microm) when compared to the control group. The same picture occurred regarding Biosilicate with granulometry 180-212 microm. Morphometric findings for bone area results (%) showed no statistically significant differences (P > 0.05) among the groups. Taken together, such findings suggest that, Biosilicate exerts more osteogenic activity when compared to Bioglass under subjective histopathological analysis.
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http://dx.doi.org/10.1007/s10856-009-3824-zDOI Listing
December 2009

Evaluation of the thermal shrinkage of titanium and the setting and thermal expansion of phosphate-bonded investments.

J Prosthet Dent 2007 Jul;98(1):24-9

Department of Dental Materials and Prosthodontics, School of Dentistry, Sao Paulo State University, Araraquara, SP, Brazil.

Statement Of Problem: There are few studies on titanium casting shrinkage, and phosphate-bonded investments for titanium casting have not produced appropriate marginal fit.

Purpose: The purpose of this study was to determine the thermal shrinkage of titanium and the setting and thermal expansion of 3 phosphate-bonded investments.

Material And Methods: The thermal shrinkage between the melting temperature and room temperature was calculated using a titanium thermal expansion coefficient. The thermal and setting expansion were measured for 3 phosphate bonded investments: Rematitan Plus (RP) specific for titanium, Rema Exakt (RE), and Castorit Super C (CA), using different special liquid concentrations (100%, 75%, and 50%). Setting expansion was measured for cylindrical specimens 50 mm long x 8 mm in diameter with a transducer. The heating and cooling curves were obtained with a dilatometer (DIL 402 PC). The total expansion curve was drawn using software, and temperatures to obtain expansion equivalent to titanium casting shrinkage were determined (n=5). In addition, the total expansion of the control group (RP at 430 degrees C) was measured, as well as the temperatures at which the other groups achieved equivalent total expansion (n=5). Data were analyzed by 1-way ANOVA and the Tukey HSD test (alpha=.05).

Results: Titanium casting shrinkage was estimated as 1.55%. RP did not achieve this expansion. RE achieved expansion of 1.55% only with a special liquid concentration of 100% at 594 degrees C. CA with all special liquid concentrations attained this expansion (351 degrees C to 572 degrees C). Total expansion of the control group was 0.86%, and the other groups reached that expansion within the range of 70 degrees C to 360 degrees C.

Conclusions: Only RE and CA demonstrated sufficient expansion to compensate for titanium casting shrinkage. All groups reached total expansion equivalent to that of the control group at significantly lower temperatures.
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http://dx.doi.org/10.1016/S0022-3913(07)60034-1DOI Listing
July 2007