Rosalia Bulnes - Academia.edu (original) (raw)

Papers by Rosalia Bulnes

Medical and Clinical Case Reports, 2021

Introduction: The maxillary skeletal expander (MSE) with the assistance of ortho implants is used... more Introduction: The maxillary skeletal expander (MSE) with the assistance of ortho implants is used to perform rapid palatal expansion in patients who are no longer growing. This case report describes a 15-year-old boy with a bilateral posterior crossbite caused by transverse maxillary deficiency. Methods: A 10-mm MSE was placed with four ortho implants. The MSE was activated once per day for 20 days. Subsequently, a fixed appliance (MBT) was placed as corrective treatment. Results: An approximate expansion of 8 mm was achieved using the MSE. The posterior crossbite was corrected by increasing the transverse dimensions of the maxilla. An adequate inter-arch relationship similar to the class I molar and canine relationships was achieved, as were a 2-mm overjet and 2-mm overbite. Conclusions: The use of the MSE with the assistance of ortho implants is an alternative method of treatment that can be beneficial for patients who are no longer growing. This method avoids the use of surgical ...

Nanobiomaterials in Dentistry, 2016

Although titanium dioxide nanoparticles (TiO 2 NPs) improve mechanical and antibacterial properti... more Although titanium dioxide nanoparticles (TiO 2 NPs) improve mechanical and antibacterial properties of conventional glass ionomer cements (GIC), their biocompatibility is still controversial. Most of the previous studies of TiO 2 NP toxicity have been done using animal models or nonoral tissue cells. We initiated a series of studies to show how TiO 2 NPs affect viability, inflammation, and drug sensitivity in human malignant and nonmalignant cells derived from the oral cavity. TiO 2 NPs did not affect the cytotoxicity of representative anticancer drugs (doxorubicin, melphalan, 5-FU, docetaxel, gefitinib) against squamous carcinoma cell lines, but significantly stimulated PGE 2 production and COX-1/COX-2 protein expression by gingival fibroblasts in synergy with interleukin-1β (IL-1β). TiO 2 NPs slightly stimulated the proliferation of gingival fibroblasts (possibly for repair synthesis), and also enhanced GIC-induced PGE 2 production, suggesting a possible link between inflammation and hormesis. TiO 2 NPs, once endocytosed into vacuoles, reduced cellular intermediate molecules of the urea cycle and polyamine, S -adenosylmethionine, and glutathione synthetic pathways. TiO 2 NPs further enhanced the IL-1β effects on cellular metabolites. Based on these experimental evidences, we recommend that dental materials containing TiO 2 NPs for patients with gingivitis or periodontitis should be used carefully. Metabolomics analysis may be useful to elucidate the mechanism of inflammation induction and explore the therapeutic strategy for gingivitis and periodontitis.

In vivo (Athens, Greece)

Despite the rapid development of nanotechnology, the biological significance of TiO2 nanoparticle... more Despite the rapid development of nanotechnology, the biological significance of TiO2 nanoparticles (NPs), possibly released from dental materials, is not well-understood. We investigated the effect of TiO2 NPs on the sensitivity of human oral squamous cell carcinoma (OSCC) cell line (HSC-2) to five popular chemotherapeutic agents. Viable cell number was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. The aggregation and cellular uptake of TiO2 NPs were assessed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. Adsorption of TiO2 NPs to anticancer drugs was assessed by the antitumor activity recovered from the TiO2 NP-free supernatant. When mixed with culture medium, TiO2 NPs instantly aggregated, and some particles were incorporated into the cells, exclusively in the vacuoles. TiO2 NPs showed no cytotoxicity nor hormetic growth stimulation at lower concentrations. Doxorubicin, melphalan, 5-flu...

In vivo (Athens, Greece)

Despite recent progress in the research of nanoparticles (NPs) spanning in many scientific fields... more Despite recent progress in the research of nanoparticles (NPs) spanning in many scientific fields, study of NPs in dentistry is limited. This triggered us to investigate the effect of TiO2 NPs on the drug-sensitivity of oral squamous cell carcinoma and inflammation of human gingival fibroblasts (HGFs). The number of viable HGF cells was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. Prostaglandin E2 (PGE2) was quantified by enzyme-linked immunosorbent assay. Contamination with lipopolysaccharide (LPS) was assayed by the endotoxin assay kit. Intracellular uptake and distribution of TiO2 NPs were assessed by transmission electron microscopy. TiO2 NPs (0.05-3.2 mM) did not affect HGF cell viability, although TiO2 NPs clusters were dose-dependently incorporated into the vacuoles of cells. Interleukin-1β (IL-1β) (3 ng/ml) stimulated the secretion of PGE2 into the culture medium by HGF cells. TiO2 NPs also induced PGE2 production, in synergy with IL-1β....

In vivo (Athens, Greece)

Incorporation of nanoparticles (NPs) into the glass ionomer cements (GICs) is known to improve th... more Incorporation of nanoparticles (NPs) into the glass ionomer cements (GICs) is known to improve their mechanical and antibacterial properties. The present study aimed to investigate the possible cytotoxicity and pro-inflammation effect of three different powdered GICs (base, core build and restorative) prepared with and without titanium dioxide (TiO2) nanoparticles. Each GIC was blended with TiO2 nanopowder, anatase phase, particle size <25 nm at 3% and 5% (w/w), and the GIC blocks of cements were prepared in a metal mold. The GICs/TiO2 nanoparticles cements were smashed up with a mortar and pestle to a fine powder, and then subjected to the sterilization by autoclaving. Human oral squamous cell carcinoma cell lines (HCS-2, HSC-3, HSC-4, Ca9-22) and human normal oral cells [gingival fibroblast (HGF), pulp (HPC) and periodontal ligament fibroblast (HPLF)] were incubated with different concentrations of GICs in the presence or absence of TiO2 nanoparticles, and the viable cell numbe...

In vivo (Athens, Greece)

Chemo-mechanical caries removal eliminates the outermost portion of the infected layer, leaving b... more Chemo-mechanical caries removal eliminates the outermost portion of the infected layer, leaving behind healthy dentine surfaces, with scarce dental tissue damage; however, the safety of caries solvents has not been established. The aim of the present study was to investigate the possible cytotoxicity of two popular chemo-mechanical caries removal agents. The cytotoxicity of Carisolv, Papacarie Duo and control vehicle solution (0.155-20% v/v) against human oral squamous cell carcinoma cells (HCS-2, HSC-3, HSC-4, Ca9-22) human gingival fibroblast (HGF), pulp (HPC) and periodontal ligament fibroblast (HPLF) was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. Prostaglandin E2 (PGE2) was quantified by enzyme-linked immunosorbent assay. Changes in fine cell structure were assessed by transmission electron microscopy. Carisolv exhibited neither cytotoxicity nor hormetic growth stimulation. Papacarie Duo significantly reduced the viable cell number within ...

Journal of Conservative Dentistry, 2014

Background: Background: Chemomechanical caries removal system is part of the minimal invasive den... more Background: Background: Chemomechanical caries removal system is part of the minimal invasive dentistry; the aim of the study was to compare the amount of bacteria after caries removal with chemomechanical system and conventional rotatory instruments and to test the Vickers microhardness and micro-RAMAN analysis of residual dentin after excavation. Materials and Methods: Materials and Methods: Molars were induced for demineralization, confirmed with DIAGNOdent; Streptococcus mutans were inoculated into the cavities and filled. Caries removal was performed with rotatory instruments and chemomechanical system; surviving bacteria were cultured for 24 and 48 hours at 37°C. Vickers microhardness and micro-RAMAN analysis were tested after excavation. Data were analyzed with Wilcoxon, continuity correction, odds ratio, ANOVA post hoc Tukey test, and Spearman correlation. Results: Results: Demineralization was significantly detectable at 240 hours of incubation; conventional rotatory instruments and chemomechanical caries removal were effective in 19.4%-22.6% and 25.8%-32.3%, respectively. Vickers microhardness of chemomechanical system was higher (P < 0.0001) than conventional rotatory instruments and comparable to healthy dentin. Micro-RAMAN analysis showed that healthy dentin is correlated to chemomechanical system (R 2 = 0.683, P < 0.00001) and drilling with burs (R 2 = 0.139, P < 0.00001). Conclusion: Conclusion:The chemomechanical system is effective for caries elimination, comparable to conventional rotatory instruments; the remaining Vickers microhardness and composition surface tissue are similar to healthy dentin.

Photomedicine and Laser Surgery, 2014

The purpose of this study was to evaluate in vitro morphological and chemical changes on human de... more The purpose of this study was to evaluate in vitro morphological and chemical changes on human deciduous enamel produced by Er:YAG laser irradiation, fluoride application, combined treatment, and acid dissolution. Er:YAG laser has been proposed as a potential preventive dental caries strategy. There is scarce information regarding deciduous enamel. Eighty enamel samples were assigned to eight groups (n=10): G1, control; G2, G3, and G4, Er:YAG laser irradiation at 7.5, 12.7, and 39.8 J/cm(2), respectively; G5, fluoride application; G6, G7, and G8, irradiation at previous densities plus fluoride application. Morphology was evaluated by scanning electron microscopy, and chemical composition was determined by energy dispersive X-ray spectroscopy before treatment (BT), after treatment (AT), and after acid dissolution (AAD). One way and repeated measures analysis of variance (ANOVA) were used (p≤0.05). Morphology of lased surfaces included craters, exposed prisms, fractures, and melting. No morphological modifications appeared after fluoride application, or AAD. Chemically, AT: C atomic percentage (at%) decreased in G3, G4, and G8; O at% decreased in G5-G8; F content was higher for G7; trace elements remained under 1.0 at%; Ca at % increased in G4, G7, and G8; there were increments in P at% in G4 and G8; and Ca/P increased in G4, G7, and G8. AAD: F at% dropped to 0.00 in G5-G8; and P at% increased in G7. Morphological changes of Er:YAG irradiated enamel represented mild to severe damages. Conditions employed in this study are not recommended for deciduous caries prevention. Er:YAG energy density influenced chemical changes in enamel to enhance its structure. Acid dissolution removed fluoride from enamel surface.

The Angle Orthodontist, 2011

To compare the influence of four systems for dental bleaching on the shear bond strength (SBS) of... more To compare the influence of four systems for dental bleaching on the shear bond strength (SBS) of orthodontic brackets. One-hundred and fifty freshly extracted bovine teeth were randomly divided into five groups. In group I the teeth were untreated (control). In the remaining groups the teeth were bleached, as follows: group II: 38% hydrogen peroxide; group III: 10% carbamide peroxide; group IV: resin-based coating material (RBCM), Beauty Coat; and group V: RBCM, White Coat. In all groups the enamel was conditioned with a self-etching primer and brackets were bonded with composite resin. Samples were stored (37°C, 24 hours), tested, and statistically analyzed, with significance predetermined at P ≤ .05. The adhesive remnant index (ARI) was also evaluated and analyzed. The SBS of group V (22.49 ± 5.34 MPa) was significantly higher than that of all other groups (I: 17.1 ± 5.11 MPa; II: 14.72 ± 5.42 MPa; III: 12.04 ± 5.29 MPa; and IV: 18.23 ± 5.58 MPa). In contrast, the SBS of group III was significantly lower than that of all groups (except group II). Significant differences in the ARI scores were present between groups. The use of RBCM for dental bleaching before bonding orthodontic brackets did not reduce the SBS. In contrast, hydrogen and carbamide peroxides negatively affected the SBS. The SBS yielded after bleaching with carbamide peroxide was significantly lower.

Scanning Electron Microscopy (SEM) coupled with Energy Dispersive Sperctroscopy (EDS) are two ana... more Scanning Electron Microscopy (SEM) coupled with Energy Dispersive Sperctroscopy (EDS) are two analysis techniques that are widely used to study all kinds of solid samples, from inorganic to biological. They are used to determine morphological features of interest at a micron and sub-micron level as well as to study the chemical composition of the samples in terms of the amount of each element present. Although these analytical techniques are "routine work" in many research areas, it is not the case of the dental area, mainly because the lack of this equipment in the dental research institutes and in dental schools. Therefore, in this chapter we show the SEM/EDS techniques applied to human dental samples when irradiated with a laser Er:YAG to prevent caries. The intention of this work is to show step by step this analysis showing the key variables to consider when working with this type of biological samples. We explain the SEM conditions to obtain satisfactory images especially when it is important to follow a sequence of steps of a treatment in-vitro that changes the morphological structure of the teeth surface. Also, we discuss the EDS analysis to semiquantitatively determine the elements and their abundance in the dental samples.

Objetivo. Determinar la morfología, composición química, estructura y las fases cristalinas carac... more Objetivo. Determinar la morfología, composición química, estructura y las fases cristalinas características de la superficie del esmalte de los dientes temporales humanos sanos y evaluar los cambios morfológicos y químicos producidos en éste por la irradiación con láser Er:YAG, la aplicación de fluoruro, el tratamiento combinado y la disolución ácida in vitro. Antecedentes. La caries dental es la enfermedad crónica más común en la infancia y el conocimiento profundo del esmalte temporal sano es requerido para mejorar las estrategias de prevención y tratamiento, incluyendo la síntesis de nuevos materiales bioactivos. El láser Er:YAG ha sido propuesto como una potencial estrategia preventiva, pero existe escasa información concerniente al esmalte temporal. Material y Métodos. Fase I. El esmalte de 30 dientes temporales humanos fue examinado mediante:

Journal of Applied Oral Science, 2012

I n Orthodontics, fixed appliances placed in the oral cavity are colonized by microorganisms. Obj... more I n Orthodontics, fixed appliances placed in the oral cavity are colonized by microorganisms. Objective: The purpose of this study was to quantitatively determine the independent bacterial colonization of S. mutans and S. sobrinus in orthodontic composite resins. Material and methods: Seven orthodontic composite adhesives for bonding brackets were selected and classified into 14 groups; (GIm, GIs) Enlight, (GIIm, GIIs) Grengloo, (GIIIm, GIIIs) Kurasper F, (GIVm, GIVs) BeautyOrtho Bond, (GVm, GVs) Transbond CC, (GVIm, GVIs) Turbo Bond II, (GVIIm, GVIIs) Blugloo. 60 blocks of 4x4x1 mm of each orthodontic composite resin were made (total 420 blocks), and gently polished with sandpaper and ultrasonically cleaned. S. mutans and S. sobrinus were independently cultivated. For the quantitative analysis, a radioactive marker was used to codify the bacteria (3 H) adhered to the surface of the materials. The blocks were submerged in a solution with microorganisms previously radiolabeled and separated (210 blocks for S. mutans and 210 blocks for S. sobrinus) for 2 hours at 37ºC. Next, the blocks were placed in a combustion system, to capture the residues and measure the radiation. The statistical analysis was calculated with the ANOVA test (Sheffè post-hoc). Results: Significant differences of bacterial adhesion were found amongst the groups. In the GIm and GIs the significant lowest scores for both microorganisms were shown; in contrast, the values of GVII for both bacteria were significantly the highest. Conclusions: This study showed that the orthodontic composite resin evaluated in the GIm and GIs, obtained the lowest adherence of S. mutans and S. sobrinus, which may reduce the enamel demineralization and the risk of white spot lesion formation.

This study compared newer composite resin restorative materials to the Vitapan Classical tabs the... more This study compared newer composite resin restorative materials to the Vitapan Classical tabs they purported to represent. Five Vitapan Classical tabs were studied: A3.5, B2, C1, C3, and D2 (n=3). These tabs created a variety of levels of lightness, chroma and hue. Each of these five shade tabs was removed from three different shade guides, and an intraoral spectrophotometer was used to capture CIELAB color coordinates. Three separate readings were made and all nine were averaged. The inter-tab color differences were also calculated. Five specimens approximately 4.0mm thick were fabricated for each of the shades studied using five different composite resin materials. Composite specimens were of the same size and shape as target shade tabs, and three separate recordings were made for each of them. This average was compared to five Vitapan Classical shade tabs to calculate the color differences using both CIELAB and CIEDE2000 color difference formulas. Color differences were compared to thresholds for perceptibility and acceptability reported in other studies. CIELAB and CIEDE2000 color differences ranged from 3.9 to 22.8 and from 2.1 to 13.8, respectively. None of the materials proved, an acceptable CIELAB color match to any of the shades tested. When various shade tabs of Vitapan Classical shade guides were compared with correspondent tabs made of direct restorative composites, no material/shade combination resulted in an acceptable mismatch relative to the used standard of acceptability. Therefore, evaluated resin composites exhibited poor match compared to target Vitapan Classical tabs.

Photomedicine and Laser Surgery, 2014

Objective: The purpose of this study was to evaluate in vitro morphological and chemical changes ... more Objective: The purpose of this study was to evaluate in vitro morphological and chemical changes on human deciduous enamel produced by Er:YAG laser irradiation, fluoride application, combined treatment, and acid dissolution. Background data: Er:YAG laser has been proposed as a potential preventive dental caries strategy. There is scarce information regarding deciduous enamel. Methods: Eighty enamel samples were assigned to eight groups (n = 10): G1, control; G2, G3, and G4, Er:YAG laser irradiation at 7.5, 12.7, and 39.8 J/cm 2 , respectively; G5, fluoride application; G6, G7, and G8, irradiation at previous densities plus fluoride application. Morphology was evaluated by scanning electron microscopy, and chemical composition was determined by energy dispersive X-ray spectroscopy before treatment (BT), after treatment (AT), and after acid dissolution (AAD). One way and repeated measures analysis of variance (ANOVA) were used ( p £ 0.05). Results: Morphology of lased surfaces included craters, exposed prisms, fractures, and melting. No morphological modifications appeared after fluoride application, or AAD. Chemically, AT: C atomic percentage (at%) decreased in G3, G4, and G8; O at% decreased in G5-G8; F content was higher for G7; trace elements remained under 1.0 at%; Ca at % increased in G4, G7, and G8; there were increments in P at% in G4 and G8; and Ca/P increased in G4, G7, and G8. AAD: F at% dropped to 0.00 in G5-G8; and P at% increased in G7. Conclusions: Morphological changes of Er:YAG irradiated enamel represented mild to severe damages. Conditions employed in this study are not recommended for deciduous caries prevention. Er:YAG energy density influenced chemical changes in enamel to enhance its structure. Acid dissolution removed fluoride from enamel surface.

Medical and Clinical Case Reports, 2021

Introduction: The maxillary skeletal expander (MSE) with the assistance of ortho implants is used... more Introduction: The maxillary skeletal expander (MSE) with the assistance of ortho implants is used to perform rapid palatal expansion in patients who are no longer growing. This case report describes a 15-year-old boy with a bilateral posterior crossbite caused by transverse maxillary deficiency. Methods: A 10-mm MSE was placed with four ortho implants. The MSE was activated once per day for 20 days. Subsequently, a fixed appliance (MBT) was placed as corrective treatment. Results: An approximate expansion of 8 mm was achieved using the MSE. The posterior crossbite was corrected by increasing the transverse dimensions of the maxilla. An adequate inter-arch relationship similar to the class I molar and canine relationships was achieved, as were a 2-mm overjet and 2-mm overbite. Conclusions: The use of the MSE with the assistance of ortho implants is an alternative method of treatment that can be beneficial for patients who are no longer growing. This method avoids the use of surgical ...

Nanobiomaterials in Dentistry, 2016

Although titanium dioxide nanoparticles (TiO 2 NPs) improve mechanical and antibacterial properti... more Although titanium dioxide nanoparticles (TiO 2 NPs) improve mechanical and antibacterial properties of conventional glass ionomer cements (GIC), their biocompatibility is still controversial. Most of the previous studies of TiO 2 NP toxicity have been done using animal models or nonoral tissue cells. We initiated a series of studies to show how TiO 2 NPs affect viability, inflammation, and drug sensitivity in human malignant and nonmalignant cells derived from the oral cavity. TiO 2 NPs did not affect the cytotoxicity of representative anticancer drugs (doxorubicin, melphalan, 5-FU, docetaxel, gefitinib) against squamous carcinoma cell lines, but significantly stimulated PGE 2 production and COX-1/COX-2 protein expression by gingival fibroblasts in synergy with interleukin-1β (IL-1β). TiO 2 NPs slightly stimulated the proliferation of gingival fibroblasts (possibly for repair synthesis), and also enhanced GIC-induced PGE 2 production, suggesting a possible link between inflammation and hormesis. TiO 2 NPs, once endocytosed into vacuoles, reduced cellular intermediate molecules of the urea cycle and polyamine, S -adenosylmethionine, and glutathione synthetic pathways. TiO 2 NPs further enhanced the IL-1β effects on cellular metabolites. Based on these experimental evidences, we recommend that dental materials containing TiO 2 NPs for patients with gingivitis or periodontitis should be used carefully. Metabolomics analysis may be useful to elucidate the mechanism of inflammation induction and explore the therapeutic strategy for gingivitis and periodontitis.

In vivo (Athens, Greece)

Despite the rapid development of nanotechnology, the biological significance of TiO2 nanoparticle... more Despite the rapid development of nanotechnology, the biological significance of TiO2 nanoparticles (NPs), possibly released from dental materials, is not well-understood. We investigated the effect of TiO2 NPs on the sensitivity of human oral squamous cell carcinoma (OSCC) cell line (HSC-2) to five popular chemotherapeutic agents. Viable cell number was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. The aggregation and cellular uptake of TiO2 NPs were assessed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. Adsorption of TiO2 NPs to anticancer drugs was assessed by the antitumor activity recovered from the TiO2 NP-free supernatant. When mixed with culture medium, TiO2 NPs instantly aggregated, and some particles were incorporated into the cells, exclusively in the vacuoles. TiO2 NPs showed no cytotoxicity nor hormetic growth stimulation at lower concentrations. Doxorubicin, melphalan, 5-flu...

In vivo (Athens, Greece)

Despite recent progress in the research of nanoparticles (NPs) spanning in many scientific fields... more Despite recent progress in the research of nanoparticles (NPs) spanning in many scientific fields, study of NPs in dentistry is limited. This triggered us to investigate the effect of TiO2 NPs on the drug-sensitivity of oral squamous cell carcinoma and inflammation of human gingival fibroblasts (HGFs). The number of viable HGF cells was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. Prostaglandin E2 (PGE2) was quantified by enzyme-linked immunosorbent assay. Contamination with lipopolysaccharide (LPS) was assayed by the endotoxin assay kit. Intracellular uptake and distribution of TiO2 NPs were assessed by transmission electron microscopy. TiO2 NPs (0.05-3.2 mM) did not affect HGF cell viability, although TiO2 NPs clusters were dose-dependently incorporated into the vacuoles of cells. Interleukin-1β (IL-1β) (3 ng/ml) stimulated the secretion of PGE2 into the culture medium by HGF cells. TiO2 NPs also induced PGE2 production, in synergy with IL-1β....

In vivo (Athens, Greece)

Incorporation of nanoparticles (NPs) into the glass ionomer cements (GICs) is known to improve th... more Incorporation of nanoparticles (NPs) into the glass ionomer cements (GICs) is known to improve their mechanical and antibacterial properties. The present study aimed to investigate the possible cytotoxicity and pro-inflammation effect of three different powdered GICs (base, core build and restorative) prepared with and without titanium dioxide (TiO2) nanoparticles. Each GIC was blended with TiO2 nanopowder, anatase phase, particle size <25 nm at 3% and 5% (w/w), and the GIC blocks of cements were prepared in a metal mold. The GICs/TiO2 nanoparticles cements were smashed up with a mortar and pestle to a fine powder, and then subjected to the sterilization by autoclaving. Human oral squamous cell carcinoma cell lines (HCS-2, HSC-3, HSC-4, Ca9-22) and human normal oral cells [gingival fibroblast (HGF), pulp (HPC) and periodontal ligament fibroblast (HPLF)] were incubated with different concentrations of GICs in the presence or absence of TiO2 nanoparticles, and the viable cell numbe...

In vivo (Athens, Greece)

Chemo-mechanical caries removal eliminates the outermost portion of the infected layer, leaving b... more Chemo-mechanical caries removal eliminates the outermost portion of the infected layer, leaving behind healthy dentine surfaces, with scarce dental tissue damage; however, the safety of caries solvents has not been established. The aim of the present study was to investigate the possible cytotoxicity of two popular chemo-mechanical caries removal agents. The cytotoxicity of Carisolv, Papacarie Duo and control vehicle solution (0.155-20% v/v) against human oral squamous cell carcinoma cells (HCS-2, HSC-3, HSC-4, Ca9-22) human gingival fibroblast (HGF), pulp (HPC) and periodontal ligament fibroblast (HPLF) was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. Prostaglandin E2 (PGE2) was quantified by enzyme-linked immunosorbent assay. Changes in fine cell structure were assessed by transmission electron microscopy. Carisolv exhibited neither cytotoxicity nor hormetic growth stimulation. Papacarie Duo significantly reduced the viable cell number within ...

Journal of Conservative Dentistry, 2014

Background: Background: Chemomechanical caries removal system is part of the minimal invasive den... more Background: Background: Chemomechanical caries removal system is part of the minimal invasive dentistry; the aim of the study was to compare the amount of bacteria after caries removal with chemomechanical system and conventional rotatory instruments and to test the Vickers microhardness and micro-RAMAN analysis of residual dentin after excavation. Materials and Methods: Materials and Methods: Molars were induced for demineralization, confirmed with DIAGNOdent; Streptococcus mutans were inoculated into the cavities and filled. Caries removal was performed with rotatory instruments and chemomechanical system; surviving bacteria were cultured for 24 and 48 hours at 37°C. Vickers microhardness and micro-RAMAN analysis were tested after excavation. Data were analyzed with Wilcoxon, continuity correction, odds ratio, ANOVA post hoc Tukey test, and Spearman correlation. Results: Results: Demineralization was significantly detectable at 240 hours of incubation; conventional rotatory instruments and chemomechanical caries removal were effective in 19.4%-22.6% and 25.8%-32.3%, respectively. Vickers microhardness of chemomechanical system was higher (P < 0.0001) than conventional rotatory instruments and comparable to healthy dentin. Micro-RAMAN analysis showed that healthy dentin is correlated to chemomechanical system (R 2 = 0.683, P < 0.00001) and drilling with burs (R 2 = 0.139, P < 0.00001). Conclusion: Conclusion:The chemomechanical system is effective for caries elimination, comparable to conventional rotatory instruments; the remaining Vickers microhardness and composition surface tissue are similar to healthy dentin.

Photomedicine and Laser Surgery, 2014

The purpose of this study was to evaluate in vitro morphological and chemical changes on human de... more The purpose of this study was to evaluate in vitro morphological and chemical changes on human deciduous enamel produced by Er:YAG laser irradiation, fluoride application, combined treatment, and acid dissolution. Er:YAG laser has been proposed as a potential preventive dental caries strategy. There is scarce information regarding deciduous enamel. Eighty enamel samples were assigned to eight groups (n=10): G1, control; G2, G3, and G4, Er:YAG laser irradiation at 7.5, 12.7, and 39.8 J/cm(2), respectively; G5, fluoride application; G6, G7, and G8, irradiation at previous densities plus fluoride application. Morphology was evaluated by scanning electron microscopy, and chemical composition was determined by energy dispersive X-ray spectroscopy before treatment (BT), after treatment (AT), and after acid dissolution (AAD). One way and repeated measures analysis of variance (ANOVA) were used (p≤0.05). Morphology of lased surfaces included craters, exposed prisms, fractures, and melting. No morphological modifications appeared after fluoride application, or AAD. Chemically, AT: C atomic percentage (at%) decreased in G3, G4, and G8; O at% decreased in G5-G8; F content was higher for G7; trace elements remained under 1.0 at%; Ca at % increased in G4, G7, and G8; there were increments in P at% in G4 and G8; and Ca/P increased in G4, G7, and G8. AAD: F at% dropped to 0.00 in G5-G8; and P at% increased in G7. Morphological changes of Er:YAG irradiated enamel represented mild to severe damages. Conditions employed in this study are not recommended for deciduous caries prevention. Er:YAG energy density influenced chemical changes in enamel to enhance its structure. Acid dissolution removed fluoride from enamel surface.

The Angle Orthodontist, 2011

To compare the influence of four systems for dental bleaching on the shear bond strength (SBS) of... more To compare the influence of four systems for dental bleaching on the shear bond strength (SBS) of orthodontic brackets. One-hundred and fifty freshly extracted bovine teeth were randomly divided into five groups. In group I the teeth were untreated (control). In the remaining groups the teeth were bleached, as follows: group II: 38% hydrogen peroxide; group III: 10% carbamide peroxide; group IV: resin-based coating material (RBCM), Beauty Coat; and group V: RBCM, White Coat. In all groups the enamel was conditioned with a self-etching primer and brackets were bonded with composite resin. Samples were stored (37°C, 24 hours), tested, and statistically analyzed, with significance predetermined at P ≤ .05. The adhesive remnant index (ARI) was also evaluated and analyzed. The SBS of group V (22.49 ± 5.34 MPa) was significantly higher than that of all other groups (I: 17.1 ± 5.11 MPa; II: 14.72 ± 5.42 MPa; III: 12.04 ± 5.29 MPa; and IV: 18.23 ± 5.58 MPa). In contrast, the SBS of group III was significantly lower than that of all groups (except group II). Significant differences in the ARI scores were present between groups. The use of RBCM for dental bleaching before bonding orthodontic brackets did not reduce the SBS. In contrast, hydrogen and carbamide peroxides negatively affected the SBS. The SBS yielded after bleaching with carbamide peroxide was significantly lower.

Scanning Electron Microscopy (SEM) coupled with Energy Dispersive Sperctroscopy (EDS) are two ana... more Scanning Electron Microscopy (SEM) coupled with Energy Dispersive Sperctroscopy (EDS) are two analysis techniques that are widely used to study all kinds of solid samples, from inorganic to biological. They are used to determine morphological features of interest at a micron and sub-micron level as well as to study the chemical composition of the samples in terms of the amount of each element present. Although these analytical techniques are "routine work" in many research areas, it is not the case of the dental area, mainly because the lack of this equipment in the dental research institutes and in dental schools. Therefore, in this chapter we show the SEM/EDS techniques applied to human dental samples when irradiated with a laser Er:YAG to prevent caries. The intention of this work is to show step by step this analysis showing the key variables to consider when working with this type of biological samples. We explain the SEM conditions to obtain satisfactory images especially when it is important to follow a sequence of steps of a treatment in-vitro that changes the morphological structure of the teeth surface. Also, we discuss the EDS analysis to semiquantitatively determine the elements and their abundance in the dental samples.

Objetivo. Determinar la morfología, composición química, estructura y las fases cristalinas carac... more Objetivo. Determinar la morfología, composición química, estructura y las fases cristalinas características de la superficie del esmalte de los dientes temporales humanos sanos y evaluar los cambios morfológicos y químicos producidos en éste por la irradiación con láser Er:YAG, la aplicación de fluoruro, el tratamiento combinado y la disolución ácida in vitro. Antecedentes. La caries dental es la enfermedad crónica más común en la infancia y el conocimiento profundo del esmalte temporal sano es requerido para mejorar las estrategias de prevención y tratamiento, incluyendo la síntesis de nuevos materiales bioactivos. El láser Er:YAG ha sido propuesto como una potencial estrategia preventiva, pero existe escasa información concerniente al esmalte temporal. Material y Métodos. Fase I. El esmalte de 30 dientes temporales humanos fue examinado mediante:

Journal of Applied Oral Science, 2012

I n Orthodontics, fixed appliances placed in the oral cavity are colonized by microorganisms. Obj... more I n Orthodontics, fixed appliances placed in the oral cavity are colonized by microorganisms. Objective: The purpose of this study was to quantitatively determine the independent bacterial colonization of S. mutans and S. sobrinus in orthodontic composite resins. Material and methods: Seven orthodontic composite adhesives for bonding brackets were selected and classified into 14 groups; (GIm, GIs) Enlight, (GIIm, GIIs) Grengloo, (GIIIm, GIIIs) Kurasper F, (GIVm, GIVs) BeautyOrtho Bond, (GVm, GVs) Transbond CC, (GVIm, GVIs) Turbo Bond II, (GVIIm, GVIIs) Blugloo. 60 blocks of 4x4x1 mm of each orthodontic composite resin were made (total 420 blocks), and gently polished with sandpaper and ultrasonically cleaned. S. mutans and S. sobrinus were independently cultivated. For the quantitative analysis, a radioactive marker was used to codify the bacteria (3 H) adhered to the surface of the materials. The blocks were submerged in a solution with microorganisms previously radiolabeled and separated (210 blocks for S. mutans and 210 blocks for S. sobrinus) for 2 hours at 37ºC. Next, the blocks were placed in a combustion system, to capture the residues and measure the radiation. The statistical analysis was calculated with the ANOVA test (Sheffè post-hoc). Results: Significant differences of bacterial adhesion were found amongst the groups. In the GIm and GIs the significant lowest scores for both microorganisms were shown; in contrast, the values of GVII for both bacteria were significantly the highest. Conclusions: This study showed that the orthodontic composite resin evaluated in the GIm and GIs, obtained the lowest adherence of S. mutans and S. sobrinus, which may reduce the enamel demineralization and the risk of white spot lesion formation.

This study compared newer composite resin restorative materials to the Vitapan Classical tabs the... more This study compared newer composite resin restorative materials to the Vitapan Classical tabs they purported to represent. Five Vitapan Classical tabs were studied: A3.5, B2, C1, C3, and D2 (n=3). These tabs created a variety of levels of lightness, chroma and hue. Each of these five shade tabs was removed from three different shade guides, and an intraoral spectrophotometer was used to capture CIELAB color coordinates. Three separate readings were made and all nine were averaged. The inter-tab color differences were also calculated. Five specimens approximately 4.0mm thick were fabricated for each of the shades studied using five different composite resin materials. Composite specimens were of the same size and shape as target shade tabs, and three separate recordings were made for each of them. This average was compared to five Vitapan Classical shade tabs to calculate the color differences using both CIELAB and CIEDE2000 color difference formulas. Color differences were compared to thresholds for perceptibility and acceptability reported in other studies. CIELAB and CIEDE2000 color differences ranged from 3.9 to 22.8 and from 2.1 to 13.8, respectively. None of the materials proved, an acceptable CIELAB color match to any of the shades tested. When various shade tabs of Vitapan Classical shade guides were compared with correspondent tabs made of direct restorative composites, no material/shade combination resulted in an acceptable mismatch relative to the used standard of acceptability. Therefore, evaluated resin composites exhibited poor match compared to target Vitapan Classical tabs.

Photomedicine and Laser Surgery, 2014

Objective: The purpose of this study was to evaluate in vitro morphological and chemical changes ... more Objective: The purpose of this study was to evaluate in vitro morphological and chemical changes on human deciduous enamel produced by Er:YAG laser irradiation, fluoride application, combined treatment, and acid dissolution. Background data: Er:YAG laser has been proposed as a potential preventive dental caries strategy. There is scarce information regarding deciduous enamel. Methods: Eighty enamel samples were assigned to eight groups (n = 10): G1, control; G2, G3, and G4, Er:YAG laser irradiation at 7.5, 12.7, and 39.8 J/cm 2 , respectively; G5, fluoride application; G6, G7, and G8, irradiation at previous densities plus fluoride application. Morphology was evaluated by scanning electron microscopy, and chemical composition was determined by energy dispersive X-ray spectroscopy before treatment (BT), after treatment (AT), and after acid dissolution (AAD). One way and repeated measures analysis of variance (ANOVA) were used ( p £ 0.05). Results: Morphology of lased surfaces included craters, exposed prisms, fractures, and melting. No morphological modifications appeared after fluoride application, or AAD. Chemically, AT: C atomic percentage (at%) decreased in G3, G4, and G8; O at% decreased in G5-G8; F content was higher for G7; trace elements remained under 1.0 at%; Ca at % increased in G4, G7, and G8; there were increments in P at% in G4 and G8; and Ca/P increased in G4, G7, and G8. AAD: F at% dropped to 0.00 in G5-G8; and P at% increased in G7. Conclusions: Morphological changes of Er:YAG irradiated enamel represented mild to severe damages. Conditions employed in this study are not recommended for deciduous caries prevention. Er:YAG energy density influenced chemical changes in enamel to enhance its structure. Acid dissolution removed fluoride from enamel surface.