Brazilian Oral Research, Volume: 27, Issue: 4, Published: 2013
  • Evaluation of scientific merit Editorial

    Estrela, Carlos; Cury, Altair Antoninha Del Bel
  • Effect of sodium ascorbate on the bond strength of silorane and methacrylate composites after vital bleaching Dental Materials

    Güler, Eda; Gönülol, Nihan; Özyilmaz, Özgün Yusuf; Yücel, Ali Çağin

    Abstract in English:

    We investigated the effect of sodium ascorbate (SA) on the microtensile bond strengths (MTBSs) of different composites to bovine enamel after vital bleaching with hydrogen peroxide (HP) or carbamide peroxide (CP). Thirty bovine incisors were randomly divided into five groups and treated with no bleaching application (control), 35% HP alone, 35% HP + 10% SA for 10 minutes (HP + SA), 16% CP alone, or 16% CP + 10% SA for 10 minutes (CP + SA). Specimens were restored with Silorane adhesive and Filtek Silorane composite (designated as S / group) or with Clearfil SE bond and Filtek Supreme XT (designated as F / group). Composite build-up was created on the enamel. Sectioned specimens (n = 10 per group; 1 mm2; cross-sectional area) were created and stressed in a universal testing machine at 1 mm/min crosshead speed. The application of 10% SA immediately after bleaching with 16% CP or 35% HP increased the enamel MTBS, regardless of the adhesive / composite resin used. The resulting MTBS values were similar to those of the control groups. Use of 16% CP and 35% HP alone decreased the enamel MTBS, regardless of the adhesive / composite resin used, with F / CP + SA = F / HP + SA = F / CP = S / CP + SA = S / HP + SA = S / C > S / CP = S / HP = F / CP = F / HP (p < 0.05). We concluded that the application of SA for 10 minutes immediately after vital bleaching increases the enamel BS for dimethacrylate- and silorane-based composites
  • Effects of threaded post placement on strain and stress distribution of endodontically treated teeth Dental Materials

    Santos Filho, Paulo César Freitas; Soares, Paulo Vinícius; Reis, Bruno Rodrigues; Veríssimo, Crisnicaw; Soares, Carlos José

    Abstract in English:

    The aim of this study was to evaluate the effect of parallel and tapered threaded post placement on the strain and stress distribution of endodontically treated teeth. Fifteen bovine incisors were sectioned 15 mm from their apices, endodontically treated, and divided into three groups (n = 5) according to three different threaded posts: parallel threaded post (Radix-Anker, RA); tapered threaded post (Euro-Post, EP) and tapered threaded post (Reforpost II, RII). A strain-gauge was fixed on the proximal surface perpendicular to the long root axis, 2 mm from the cervical limit. Strain generated during post placement was recorded and compared using one-way ANOVA and Tukey's test (α= .05). A scanning electron microscope was used to examine the longitudinal root sections. Stress was evaluated for each group in a two-dimensional finite element analysis. The models were meshed with tetrahedron elements and loaded with 2 N at an angle of 135° to the lingual face. The equivalent Von Mises stress was calculated. The one-way ANOVA showed significant difference among the groups. The RA group (150.0 ± 12.2 A) produced higher external strain than the RII (80.0 ± 12.2 B) and the EP (70.0 ± 6.1 B) groups. The inner strain was approximately five times greater than the external dentin strain. High stress concentrations in each thread of the posts were observed. Scanning electron micrographs showed cracks that started in the threads of the posts. The threaded post placement induced root strain mainly on the parallel side post. Root strain and stress concentration on the post threads tended to create cracks in the inner root canal dentin.
  • Surface agents' influence on the flexural strength of bilaminated ceramics Dental Materials

    Lima, Júlia Magalhães Costa; Anami, Lilian Costa; Rippe, Marília Pivetta; Melo, Renata Marques de; Bottino, Marco Antonio; Valera, Márcia Carneiro; Araújo, Maria Amélia Máximo

    Abstract in English:

    The objective of this study was to evaluate the influence of different surface agents on the flexural strength of a ceramic system. Eighty bar-shaped specimens of zirconia were divided into four groups according to the agent to be used: group Control - to be cleaned with alcohol; group VM9 - application of a fluid layer of porcelain; group Effect Bonder - application of a bonding agent; and group Coloring Liquid - application of coloring liquid. All specimens received the porcelain application by the layering technique and were then subjected to thermocycling. The four-point bending test was performed to calculate the strength values (σ, MPa) and the failure modes were classified. ANOVA did not detect significant differences among the groups. The Weibull modulus were 5 (Control, VM9 and Effect Bonder) and 6 (Coloring Liquid). The cracking of the porcelain ceramic toward the interface was the predominant failure mode. It was concluded that the surface agents tested had no effect on the flexural strength of the bilaminated ceramic specimens.
  • Analysis of the color alteration and radiopacity promoted by bismuth oxide in calcium silicate cement Endodontics

    Marciano, Marina Angélica; Estrela, Carlos; Mondelli, Rafael Francisco Lia; Ordinola-Zapata, Ronald; Duarte, Marco Antonio Hungaro

    Abstract in English:

    The aim of the study was to determine if the increase in radiopacity provided by bismuth oxide is related to the color alteration of calcium silicate-based cement. Calcium silicate cement (CSC) was mixed with 0%, 15%, 20%, 30% and 50% of bismuth oxide (BO), determined by weight. Mineral trioxide aggregate (MTA) was the control group. The radiopacity test was performed according to ISO 6876/2001. The color was evaluated using the CIE system. The assessments were performed after 24 hours, 7 and 30 days of setting time, using a spectrophotometer to obtain the ΔE, Δa, Δb and ΔL values. The statistical analyses were performed using the Kruskal-Wallis/Dunn and ANOVA/Tukey tests (p < 0.05). The cements in which bismuth oxide was added showed radiopacity corresponding to the ISO recommendations ( > 3 mm equivalent of Al). The MTA group was statistically similar to the CSC / 30% BO group (p > 0.05). In regard to color, the increase of bismuth oxide resulted in a decrease in the ΔE value of the calcium silicate cement. The CSC group presented statistically higher ΔE values than the CSC / 50% BO group (p < 0.05). The comparison between 24 hours and 7 days showed higher ΔE for the MTA group, with statistical differences for the CSC / 15% BO and CSC / 50% BO groups (p < 0.05). After 30 days, CSC showed statistically higher ΔE values than CSC / 30% BO and CSC / 50% BO (p < 0.05). In conclusion, the increase in radiopacity provided by bismuth oxide has no relation to the color alteration of calcium silicate-based cements.
  • Evaluation of pH, calcium ion release and antimicrobial activity of a new calcium aluminate cement Endodontics

    Pires-de-Souza, Fernanda de Carvalho Panzeri; Moraes, Paola Castro; Garcia, Lucas da Fonseca Roberti; Aguilar, Fabiano Gamero; Watanabe, Evandro

    Abstract in English:

    This study evaluated the pH, calcium ion release and antimicrobial activity of EndoBinder (EB), containing different radiopacifiers: bismuth oxide (Bi2O3), zinc oxide (ZnO) or zirconium oxide (ZrO2), in comparison to MTA. For pH and calcium ion release tests, 5 specimens per group (n = 5) were immersed into 10 mL of distilled and deionized water at 37°C. After 2, 4, 12, 24, 48 h; 7, 14 and 28 days, the pH was measured and calcium ion release quantified in an atomic absorption spectrophotometer. For antimicrobial activity, the cements were tested against S. aureus, E. coli, E. faecalis and C. albicans, in triplicate. MTA presented higher values for pH and calcium ion release than the other groups, however, with no statistically significant difference after 28 days (p > 0.05); and the largest inhibition halos for all strains, with no significant difference (E. coli and E. faecalis) for pure EB and EB + Bi2O3 (p > 0.05). EB presented similar performance to that of MTA as regards pH and calcium ion release; however, when ZnO and ZrO2 were used, EB did not present antimicrobial activity against some strains.
  • Lack of correlation between obturation limits and apical leakage Endodontics

    Machado, Ricardo; Silva Neto, Ulisses Xavier da; Ignácio, Sérgio Aparecido; Cunha, Rodrigo Sanches

    Abstract in English:

    The aim of this paper was to evaluate a possible correlation between obturation limits and leakage. Thirty-six extracted human mandibular incisors were used, characterized by straight and single canals, non-anatomical complexities, absence of previous endodontic treatment, complete root formation and patent foramen. For standardization of the specimens for the leakage analysis, foraminal instrumentation was performed up to a Flexofile #25 (Dentsply-Maillefer, Ballaigues, Switzerland). All specimens were instrumented and filled following the same protocol, and the obturation limits were measured using Axiovision 4.5 Software (Carl Zeiss Vision, Hallbergmoos, Germany). The specimens were then separated into three groups (n = 12) according to the following variables: Group I - obturation limits ranging from 0 mm to 0.76 mm of the main apical foramen. Group II - obturation limits ranging from 0.77 mm to 0.98 mm of the main apical foramen. Group III - obturation limits ranging from 0.99 mm to 1.68 mm of the main apical foramen. Apical leakage was quantified by fluid filtration. The analyses were confronted using Pearson's test (p > 0.05). Groups I, II and III showed Pearson correlation values (r2) of -0.152, -0.186 and 0.058, respectively. No correlation was found between the obturation limits and apical leakage
  • Prevalence of caries in Brazilian children with cleft lip and∕or palate, aged 6 to 36 months Epidemiology

    Moura, Agda Maria de; André, Marcia; Lopez, Margareth Torrecillas; Dias, Reinaldo Brito e

    Abstract in English:

    The aim of this study was to assess the prevalence of caries in children with cleft lip and∕or palate aged 6-36 months of life. This study was conducted at the University of São Paulo School of Dentistry, Brazil. A total of 143 children were selected (73 male, 70 female), all of whom had at least two erupted teeth. The children were distributed as follows: 88 had cleft lip and palate, 35 had cleft palate, 20 had cleft lip. Dental caries disease was diagnosed according to criteria set by the World Health Organization. It was observed that 18.9% of the study children had caries. No correlation between prevalence of caries and gender or type of cleft was observed. Mean dmf-t was 0.47. The prevalence of caries was higher in the upper arch, and the most affected tooth was the central incisor (p = 0.001). Children with cleft lip and∕or palate did not have high caries indices.
  • Effect of laser phototherapy in the prevention and treatment of chemo-induced mucositis in hamsters Oral Medicine

    Lopez, Talita Christine Camilo; Martins, Manoela Domingues; Pavesi, Vanessa Christina Santos; Ferreira, Leila Soares; Bussadori, Sandra Kalil; Moreira, Maria Stella; Marques, Márcia Martins

    Abstract in English:

    The aim of this study was to investigate the effect of laser phototherapy (LPT) in the prevention and/or treatment of oral mucositis induced by 5-fluorouracil (5-FU; Eurofarma, São Paulo, Brazil) in hamsters. Ninety-six hamsters were divided into four groups (n = 24): Control (no treatment); Preventive [LPT from day (D) D-5 to D+5]; Therapeutic (LPT from D+5 to D+15); and Combined (preventive plus therapeutic LPT from D-5 to D+15). The animals received an intraperitoneal injection of 5-FU on Days 0 and 2. The pouch mucosa was scratched on Days 3 and 4. The irradiation parameters were: indium-gallium-aluminum-phosphide (InGaAlP) diode laser (MM Optics, São Carlos, Brazil) (660 nm), beam area of 0.036 cm2, 40 mW, 1.11 W/cm2, 6.6 J/cm2, power density applied daily of 39.6 J/cm2, in punctual mode (six points and six seconds per point) and contact mode, one application per day. The animals were sacrificed on Days 0, 5, 10 and 15 (n = 6) and weighed, and the pouch mucosa was removed for histopathological analysis. Clinical and corresponding histological scores were compared using ANOVA and Tukey's test (p ≤0.05). Similar weight losses ranging from 5% to 10% occurred in all groups. The therapeutic group had significantly lower clinical and histological scores than the other groups at Day 10. This study showed that positive effects on oral mucositis management were obtained only when LPT was applied in the therapeutic protocol (from D+5 to D+15 after chemotherapy).
  • Survival in patients with oral and maxillofacial diffuse large B-cell lymphoma Oral Pathology

    Guevara-Canales, Janet Ofelia; Morales-Vadillo, Rafael; Cava-Vergiú, Carlos Enrique; Leite, Fabiola Pessoa Pereira; Netto, Henrique Duque de Miranda Chaves; Soares, Fernando Augusto; Chaves, Maria das Graças Afonso Mirand

    Abstract in English:

    The purpose of this study was to determine the survival and prognostic factors of patients with diffuse large B-cell lymphoma (DLBCL) of the oral cavity and maxillofacial region. Retrospectively, the clinical records of patients with a primary diagnosis of DLBCL of the oral cavity and maxillofacial region treated at the A.C. Camargo Hospital for Cancer, São Paulo, Brazil, between January 1980 and December 2005 were evaluated to determine (A) overall survival (OS) at 2 and 5 years and the individual survival percentage for each possible prognostic factor by means of the actuarial technique (also known as mortality tables), and the Kaplan Meier product limit method (which provided the survival value curves for each possible prognostic factor); (B) prognostic factors subject to univariate evaluation with the log-rank test (also known as Mantel-Cox), and multivariate analysis with Cox's regression model (all the variables together). The data were considered significant at p ≤ 0.05. From 1980 to 2005, 3513 new cases of lymphomas were treated, of which 151 (4.3%) occurred in the oral cavity and maxillofacial region. Of these 151 lesions, 48 were diffuse large B-cell lymphoma, with 64% for OS at 2 years and 45% for OS at 5 years. Of the variables studied as possible prognostic factors, multivariate analysis found the following variables have statistically significant values: age (p = 0.042), clinical stage (p = 0.007) and performance status (p = 0.031). These data suggest that patients have a higher risk of mortality if they are older, at a later clinical stage, and have a higher performance status.
  • Factors associated with the development of early childhood caries among Brazilian preschoolers Pediatric Dentistry

    Corrêa-Faria, Patrícia; Martins-Júnior, Paulo Antônio; Vieira-Andrade, Raquel Gonçalves; Marques, Leandro Silva; Ramos-Jorge, Maria Letícia

    Abstract in English:

    The aim of this study was to assess the prevalence of early childhood caries (ECC) in children and investigate the influence of sociodemographic variables, quality of oral hygiene and child-related aspects. A cross-sectional study was carried out with 593 children aged three to five years. Data were collected through clinical examinations and interviews with parents. Interviews with parents of the children were conducted to acquire information on sociodemographic aspects, breastfeeding, bottle feeding and harmful oral habits. Statistical analysis involved the chi-square test and the Poisson regression. The prevalence of ECC was 53.6%. The occurrence of ECC was greater among children with unsatisfactory oral hygiene (PR: 2.95; 95% CI: 2.42-3.60) and those from a family with a lower monthly household income (PR: 1.62; 95% CI: 1.24-2.10). In conclusion, unsatisfactory oral hygiene and monthly income exerted an influence on the occurrence of ECC among preschoolers.
  • Perinatal factors associated with developmental defects of enamel in primary teeth: a case-control study Pediatric Dentistry

    Corrêa-Faria, Patrícia; Martins-Júnior, Paulo Antônio; Vieira-Andrade, Raquel Gonçalves; Marques, Leandro Silva; Ramos-Jorge, Maria Letícia

    Abstract in English:

    The present study was designed to evaluate associations between developmental defects of enamel (DDE) in the primary dentition and aspects related to mothers and preschoolers in the city of Diamantina, Brazil. A case-control study was carried out involving children aged three to five years. The case group was composed of 104 children with at least one dental surface affected by DDE. The control group comprised 105 children without DDE, matched for gender and age. The diagnosis of enamel defects was performed using the Developmental Defects of Enamel Index. Information was collected through interviews investigating socio-demographic aspects, gestation, birth weight, prematurity and breastfeeding. Simple and multiple regression analyses were performed, providing unadjusted and adjusted prevalence ratios (Poisson regression). DDE were more prevalent among children who had not been breastfed (PR = 1.57; 95% CI: 1.1-2.2) and those whose mothers were under 24 years of age at the birth of the child (PR = 1.41; 95% CI: 1.1-1.9). The prevalence of DDE in the primary dentition was higher among children who had not been breastfed and those whose mothers were under 24 years of age at the birth of the child.
  • Influence of substratum position and acquired pellicle on Candida albicans biofilm Prosthodontics

    Cavalcanti, Indira Moraes Gomes; Silva, Wander José da; Lucena, Silvia Carneiro de; Pousa, Camila Cordeiro; Cury, Altair Antoninha Del Bel

    Abstract in English:

    The purpose of this study was to evaluate the influence of the substratum position and the saliva acquired pellicle (AP) on Candida albicans biofilm development. Poly(methylmethacrylate) (PMMA) disks were fabricated and randomly allocated to experimental groups: HNP (disks placed in a horizontal position and uncoated by pellicle), VNP (disks placed in a vertical position and uncoated by pellicle), HCP (disks placed in a horizontal position and coated by pellicle), and VCP (disks placed in a vertical position and coated by pellicle). Disks were placed in a 24-well plate and a suspension of 107 cells/mL of Candida albicans was added to each well for biofilm development. The plates were aerobically incubated at 35°C. The biofilms were evaluated at 1.5 (adhesion time point), 24, 48, 72, and 96 hours. The number of viable cells was quantified in terms of the colony-forming units per milliliter (CFU/mL). Metabolic activity was measured by the XTT assay. The biofilm structure was analyzed by scanning electron microscopy. The data were analyzed by three-way ANOVA followed by Tukey's test, with significance set at 5%. The vertical groups showed less biofilm formation and lower metabolic activity than the horizontal groups (p< 0.05). Significant differences in cell viability and metabolic activity were observed between the adhesion and other time points (p< 0.05), but these variables were not affected by the presence of the pellicle (p > 0.05). It can be concluded that the substratum position influenced biofilm development.
  • Conditional factors for untreated caries in 12-year-old children in the city of São Paulo Public Health

    Lopes, Raquel Marianna; Domingues, Gabrielle Gonsalli; Junqueira, Simone Rennó; Araujo, Maria Ercilia de; Frias, Antônio Carlos

    Abstract in English:

    The aim of the study was to analyze what sociodemographic and economic variables were associated with the presence of untreated caries in 12-year-old children in the city of São Paulo. This cross-sectional study had a complex sample design. It was based on secondary data generated by the Levantamento epidemiológico em saúde bucal (Epidemiological Oral Health Survey) in the city of São Paulo, conducted in 2008, whose sample comprised 4,246 12-year-old children from the public and private schools of all the administrative districts of the city. A questionnaire was applied and an epidemiological exam was performed in accordance with the World Health Organization's (WHO) recommendations. The variables of interest were categorized into a dependent variable of untreated dental caries (carious component of the DMFT index that corresponds to carious, missing and filled teeth) and independent variables related to the socioeconomic and demographic conditions of the children and their families, and to their access to dental services. The EPI-INFO 06 and STATA 10 programs were used for the analysis; the prevalence ratio and a confidence interval of 95% were applied to the population parameters. The Poisson regression model was used, adjusted for sampling of the complex type. Caries was associated with ethnicity (higher rate in black people, p = 0.042), attending public school (p = 0.000), lower average family income (p = 0.002), overcrowded dwellings (p = 0.000) and presence of pain (p = 0.000). Caries is a multifactorial disease influenced by social health determinants that intensify its risk.
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