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Brazilian Oral Research, Volume: 24, Número: 2, Publicado: 2010
  • Change the QUALIS criteria! Editorial

    Rode, Sigmar de Mello
  • S. mutans biofilm model to evaluate antimicrobial substances and enamel demineralization Cariology

    Ccahuana-Vásquez, Renzo Alberto; Cury, Jaime Aparecido

    Resumo em Inglês:

    The aim of this study was to validate a model of S. mutans biofilm formation, which simulated 'feast-famine' episodes of exposure to sucrose that occur in the oral cavity, showed dose-response susceptibility to antimicrobials and allowed the evaluation of substances with anticaries potential. S. mutans UA159 biofilms were grown for 5 days on bovine enamel slabs at 37°C, 10% CO2. To validate the model, the biofilms were treated 2x/day with chlorhexidine digluconate (CHX) at 0.012, 0.024 and 0.12% (concentration with recognized anti-plaque effect) and 0.05% NaF (concentration with recognized anti-caries effect). CHX showed dose-response effect decreasing biomass, bacterial viability and enamel demineralization (p < 0.05). Whereas, 0.05% NaF did not show antimicrobial effect but had similar effect to that of 0.12% CHX decreasing enamel demineralization (p < 0.05). The model developed has potential to evaluate the effect of substances on biofilm growth and on enamel demineralization.
  • Use of chewing gum containing 15% of xylitol and reduction in mutans streptococci salivary levels Cariology

    Fraga, Cláudia Perez Trindade; Mayer, Márcia Pinto Alves; Rodrigues, Célia Regina Martins Delgado

    Resumo em Inglês:

    Frequent use of Xylitol may decrease the S. mutans levels. However, very little is known about whether this effect on the levels of cariogenic bacteria is maintained after the interruption of short-term usage of xylitol. This study aimed at evaluating changes in mutans streptococci (MS) salivary levels after using a chewing gum containing xylitol. Twelve volunteers harboring > 10(5) CFU MS/ml saliva levels were asked to chew Happydent-xylit® for 5 minutes, 5 X/day, for 30 days. Saliva samples were collected at baseline, at 30 days after xylitol usage began, and at 30 days beyond its interruption. MS salivary levels were estimated. The average salivary levels of MS in the ten subjects who completed the study were 13.17 (NL-CFU) at baseline (A). After the 30 days experimental period (B), this average decreased to 9.45 (NL-CFU). Nine of ten subjects studied showed a reduction in MS salivary levels in relation to baseline, whereas salivary levels were maintained in the remaining subject. At thirty days beyond the interruption of xylitol usage (C), the average levels of MS were still reduced to 10.31 (NL-CFU). Multiple sample comparison using the Bonferroni test revealed that the decrease in MS levels observed from baseline (A) to the time immediately after 30 days of xylitol usage (B) was statistically significant (p < 0.05), and those levels were still decreased between baseline and 30 days beyond the interruption of xylitol usage (C). So, the use of xylitol induced a reduction in MS salivary levels after a short period of usage which persisted beyond its interruption.
  • Effect of phosphate-bonded investments on titanium reaction layer and crown fit Dental Materials

    Rocha, Sicknan Soares da; Nogueira, Fabiane; Pieralini, Anelise Rodolfo Ferreira; Ribeiro, Ricardo Faria; Adabo, Gelson Luis

    Resumo em Inglês:

    This study analyzed the reaction layer and measured the marginal crown fit of cast titanium applied to different phosphate-bonded investments, prepared under the following conditions (liquid concentration/casting temperature): Rema Exakt (RE) - 100%/237°C, 75%/287°C, Castorit Super C (CS)-100%/70°C, 75%/141°C and Rematitan Plus (RP)- 100%/430°C (special to titanium cast, as the control group). The reaction layer was studied using the Vickers hardness test, and analyzed by two way ANOVA and Tukey's HSD tests (α = 0.05). Digital photographs were taken of the crowns seated on the die, the misfit was measured using an image analysis system and One-way ANOVA, and Tukey's test was applied (α = 0.05). The hardness decreased from the surface (601.17 VHN) to 150 μm (204.03 VHN). The group CS 75%/141°C presented higher hardness than the other groups, revealing higher surface contamination, but there were no differences among the groups at measurements deeper than 150 μm. The castings made with CS - 100%/70°C presented the lowest levels of marginal misfit, followed by RE -100%/237°C. The conventional investments CS (100%) and RE (100%) showed better marginal fit than RP, but the CS (75%) had higher surface contamination.
  • Crown-down preflaring in the determination of the first apical file Endodontics

    Silveira, Luiz Fernando Machado; Silveira, Carina Folgearini; Castro, Luis Antônio Suita de; César Neto, João Batista; Martos, Josué

    Resumo em Inglês:

    In this study, scanning electron microscopy (SEM) was used to evaluate the adaptation of the first apical file after preflaring in mesiobuccal (MB) and mesiolingual (ML) canals of mandibular molars considering the tactile sensibility as a reference. The mesial canals (n = 22) of human mandibular molar teeth were used, and the first instrument to bind to the working length was determined after preflaring and crown-down shaping. Digital images of the root apex were acquired and a single examiner determined the contact of the file with the walls using Image J software. The results showed that the file was in contact in 47.83% and 31.71% in the MB and ML canals, respectively. When the apexes are fused, the average was 40.03%. A descriptive analysis showed that the first apical file did not touch all dentin walls in any of the samples.
  • Effect of additives on the compressive strength and setting time of a Portland cement Endodontics

    Machado, Desirée Freitas Mryczka; Bertassoni, Luiz Eduardo; Souza, Evelise Machado de; Almeida, Janaina Bertoncelo de; Rached, Rodrigo Nunes

    Resumo em Inglês:

    Improvements in strength and setting time of Portland cements (PC) are needed to enhance their performance as endodontic and load bearing materials. This study sought to enhance the compressive strength and setting time of a PC by adding one of the following additives: 20% and 30% poly-methylmethacrylate (PMMA), 20% and 30% irregular and spherical amalgam alloys, and 10% CaCl2. The control consisted of unreinforced PC specimens. Setting time was determined using a Gillmore apparatus according to standardized methods while compressive strength was measured using a universal testing machine after 21 hours or 60 days of water storage. Data were analyzed by ANOVA, Tukey and Games-Howell tests (α = 5%). All additives significantly decreased both initial and final setting times as compared with the PC-control (p < .05). 30% PMMA and 30% irregular alloy had the lowest values of initial setting time. 30% irregular alloy also produced the lowest values of final setting time while 30% spherical alloy yielded the highest (p < .05). No differences were detected between the compressive strength values of 21 hours and 60 days. While 10% CaCl2, 20% and 30% PMMA produced values significantly lower than the PC-control, 30% spherical alloy significantly improved the compressive strength of the reinforced PC (p < .05). In summary, all additives significantly reduced the setting time and 30% spherical amalgam alloy yielded a significant increase in compressive strength for the tested PC, which might represent an improved composition for PCs to expand their use as endodontic and potentially load bearing materials.
  • The effect of irrigation solutions on the apical sealing ability in different root canal sealers Endodontics

    Bodrumlu, Emre; Parlak, Esra; Bodrumlu, Ebru Hazar

    Resumo em Inglês:

    The aim of this study was to assess the effect of three root canal irrigation solutions on the apical sealing ability of three root canal obturation materials: gutta-percha/AH plus or MM-seal and Resilon/Epiphany SE. A total of 100 teeth with single straight root canals were randomly divided into three equal groups of 30 samples each, with the other 10 teeth (5 positive and 5 negative) used as controls. Each irrigation group was divided into three groups according to the use of three different root canal obturation materials (n = 10): Gutta-percha with AH plus or MM-seal, Resilon with Epiphany SE. The crowns were removed at the cementoenamel junction with a diamond disc under water coolant. The root canals were prepared using step-back technique and irrigation with either sodium hypochlorite (2.5%), chlorhexidine (2%), or MTAD solutions. The roots were obturated with lateral condensation technique using one of the obturation materials. The root surfaces was coated with two layer nail varnish (except apex), placed in 2% methylene blue dye solution, and centrifuged at 3,000 rpm for 5 minutes. Irrigation solutions affected the apical sealing ability of all the sealers. The chlorhexidine irrigation solution exhibited higher apical leakage values than did MTAD and NaOCl in all canal sealers, although the MTAD irrigation solution groups showed the least leakage values. The apical sealing ability of AH plus, Epiphany SE and MM-seal root canal sealers decreased when the chlorhexidine was used as an irrigation solution.
  • Trabecular bone area and bone healing in spontaneously hypertensive rats: a histometric study Implants

    Bastos, Marta Ferreira; Brilhante, Felipe Vilhena; Bezerra, Joyce Pinho; Silva, Carlos Alberto; Duarte, Poliana Mendes

    Resumo em Inglês:

    Clinical and experimental studies have demonstrated some negative effect of hypertension on bone mineral density. The aim of this study was to evaluate bone healing and trabecular bone area (TBA) in spontaneously hypertensive rats (SHR), a well-established model of essential hypertension, when compared to normotensive rats (NTR). A critical-size defect was surgically created in the right tibia of SHR (n = 12) and normotensive rats (NTR; n = 12), while the contralateral tibia was left intact. Eight days later, the animals were sacrificed and the specimens processed in order to obtain decalcified sections. The area of newly-formed bone (NB) within the defect of the right tibia and the TBA in the left tibia were histometrically evaluated. At 8 days post-operative, SHR presented a significantly smaller area of NB when compared to NTR (p < 0.05). In addition, SHR demonstrated a lower TBA than NTR group. In conclusion, the present study demonstrated that SHR rats presented a disturbed bone healing and reduced TBA.
  • Cola beverage consumption delays alveolar bone healing: a histometric study in rats Oral Pathology

    Teófilo, Juliana Mazzonetto; Leonel, Daniel Vilela; Lamano, Teresa

    Resumo em Inglês:

    Epidemiological studies have suggested that cola beverage consumption may affect bone metabolism and increase bone fracture risk. Experimental evidence linking cola beverage consumption to deleterious effects on bone is lacking. Herein, we investigated whether cola beverage consumption from weaning to early puberty delays the rate of reparative bone formation inside the socket of an extracted tooth in rats. Twenty male Wistar rats received cola beverage (cola group) or tap water (control group) ad libitum from the age of 23 days until tooth extraction at 42 days and euthanasia 2 and 3 weeks later. The neoformed bone volume inside the alveolar socket was estimated in semi-serial longitudinal sections using a quantitative differential point-counting method. Histological examination suggested a decrease in the osteogenic process within the tooth sockets of rats from both cola groups, which had thinner and sparser new bone trabeculae. Histometric data confirmed that alveolar bone healing was significantly delayed in cola-fed rats at three weeks after tooth extraction (ANOVA, p = 0.0006, followed by Tukey's test, p < 0.01). Although the results of studies in rats cannot be extrapolated directly to human clinical dentistry, the present study provides evidence that cola beverage consumption negatively affect maxillary bone formation.
  • Cyclosporin A-induced gingival overgrowth is not associated with myofibroblast transdifferentiation Oral Pathology

    Sobral, Lays Martin; Kellermann, Michele Gassen; Graner, Edgard; Martelli-Junior, Hercilio; Coletta, Ricardo Della

    Resumo em Inglês:

    Cyclosporin A (CyA) induces gingival overgrowth via its stimulatory effects on expression of transforming growth factor-beta1 (TGF-β1) and collagen. It is not known whether CyA has a direct effect on gingival fibroblasts or induces its effect indirectly via stimulation of myofibroblast transdifferentiation. The present study was undertaken to examine the in vivo and in vitro effect of CyA on myofibroblast transdifferentiation. Rats were treated for 60 days with a daily subcutaneous injection of CyA, and the gingival overgrowth tissue was analyzed by immunohistochemistry. In vitro, fibroblasts from normal gingiva (NG) were cultured in the presence of different concentrations of CyA, and subjected to semi-quantitative reverse transcriptase-polymerase chain reaction and western blot. Although CyA treatment stimulated TGF-β1 expression by NG fibroblasts, it lacked to induce expression and production of isoform α of smooth muscle actin (α-SMA), the specific myofibroblast marker. The expression levels of connective tissue growth factor (CTGF), which has been considered a key molecule to promote the transdifferentiation of myofibroblasts via TGF-β1 activation, were unaffected by CyA. Our results demonstrate that CyA-induced gingival overgrowth is not associated with activation of myofibroblast transdifferentiation, since CyA is not capable to increase CTGF expression.
  • Cephalometric evaluation of surgical mandibular advancement Orthodontics

    Boeck, Eloísa Marcantônio; Kuramae, Mayury; Lunardi, Nádia; Santos-Pinto, Ary dos; Mazzonetto, Renato

    Resumo em Inglês:

    The treatment of Class II adult individuals with mandibular deficiency has been the combination of orthodontic treatment and orthognathic surgery. Therefore, a study was conducted in which cephalometric analysis was used to evaluate the influence of dentoalveolar decompensation in Class II patients submitted to orthodontic and surgical treatment for mandibular advancement, by bilateral osteotomy of the mandibular ramus. A sample of 15 leukoderma adult female patients were selected and three cephalometric radiographs of each patient, taken before the orthodontic treatment, before surgery and after at least 6 months postoperatively, were analyzed in a total of 45 roentgenograms. The tracings were made by the manual method and the points were digitalized using software. The results showed that values of SNB increased from 75.6 to 78.6°. The measures BNP and PGNP were reduced from -12.7 to -7.7 mm and -12.7 to -6.6 mm, respectively. For ANB there was a reduction of 3.23° (from 8.1° to 4.9°). Likewise, the values of AOBO were diminished by 6.3 mm (from 7.6 to 1.3 mm), and in the values of OJ there was a reduction of 5.7 mm (from 9 to 3.3 mm). It was concluded that the pre-surgical orthodontic treatment promoted minimal and variable dental and skeletal changes in the final result. The surgical treatment caused significant skeletal changes, especially in the measurements related to the mandible (SNB, BNP, PGNP and SNPM) or indirectly to it (ANB, AOBO and OJ).
  • Mechanical properties of one and two-step fluoridated orthodontic resins submitted to different pH cycling regimes Orthodontics

    Passalini, Paula; Fidalgo, Tatiana Kelly da Silva; Caldeira, Erika Machado; Gleiser, Rogério; Nojima, Matilde da Cunha Gonçalves; Maia, Lucianne Cople

    Resumo em Inglês:

    The aim of this study is to assess the in vitro shear bond strength and adhesive remnant index (ARI) of one and two-step fluoridated orthodontic resins under conditions that simulate high cariogenic challenge. Edgewise brackets for maxillary central incisors were randomly bonded to 80 bovine incisors, using either TransbondTM Plus Color Change orthodontic resin and a self-etching primer adhesive (G1; n = 40) or Orthodontic Fill Magic with a conventional acid-etch technique (G2; n = 40). Each group of resin (n = 10) was divided into: immediate shear (A- pre-cycling control), immersion in artificial remineralizing saliva (neutral saliva) for 14 days (B- post-cycling control) and pH cycling with high cariogenic challenge (C- acid saliva with pH 5.5 and D- acid saliva with pH 4.5). After 14 days of pH cycling, the shear bond strength and ARI were evaluated. Considering the shear bond strength, TransbondTM Plus Color Change resin was stronger than Orthodontic Fill Magic when it was submitted to high cariogenic challenge (p < 0.05). Also TransbondTM Plus Color Change resin showed better adhesion to enamel than Orthodontic Fill Magic, in all situations evaluated (p < 0.05). It could be concluded that TransbondTM Plus Color Change resin presented better shear bond strength and adhesive remnant index when submitted to high cariogenic challenge, in comparison with Orthodontic Fill Magic.
  • Characteristics of masticatory muscles in children with unilateral posterior crossbite Pediatric Dentistry

    Andrade, Annicele da Silva; Gavião, Maria Beatriz Duarte; Gameiro, Gustavo Hauber; Rossi, Moara De

    Resumo em Inglês:

    The aim of this study was to detect possible differences in the EMG (electromiography) activity, chewing rate (CR), cycle duration (CD) and preferred chewing side (PCS) between children with and without unilateral posterior crossbite. Thirty-seven children aged from 7 to 10 years were selected from the clinic of the Department of Pediatric Dentistry, Piracicaba Dental School, Brazil, and divided into two groups: unilateral posterior crossbite (UPCB group, n = 17), and normal occlusion (NOccl group, n = 20). The PCS was determined using a visual spot-checking method. The EMG activity was recorded during mastication, and two chewing sequences of 20 s were evaluated to establish each subject's CR (cycles/sec) and CD. UPCB and NOccl groups did not have a PCS. The EMG activity and the cycle characteristics did not differ between the groups. The correlations between CD, CR and EMG activity were statistically significant for the masseter and anterior temporalis muscles only in the NOccl group, in which there was also a significant correlation between the EMG activity of masseter and anterior temporalis. In conclusion, these findings suggest that although children with and without UPCB presented a bilateral masticatory pattern with similar CR and CD, balanced EMG activity of masseter and anterior temporalis muscles was observed only in the NOccl group. These results indicate that in children, UPCB can alter the coordination of masticatory muscles during mastication.
  • Dental caries in the primary dentition of a Colombian population according to the ICDAS criteria Pediatric Dentistry

    Cadavid, Alexandra Saldarriaga; Lince, Clara María Arango; Jaramillo, Marisela Cossio

    Resumo em Inglês:

    This paper describes the results of a cross-sectional study conducted with a randomized sample of 447 low-income children between 2.5 and 4 years of age selected from the files of a health institution in Medellin, Colombia. The patients were examined in 2007 using the modified criteria of the International Caries Detection and Assessment System (ICDAS); the first caries code was not used. Clinical examination was carried out by three examiners previously trained in the ICDAS. The inter-examiner agreement was rated as good (kappa 0.73 - 0.82). The prevalence of untreated caries was 74.7% (335) with a mean of 9.7 ± 9.4 affected surfaces. The prevalence of caries (treated and untreated) was 74.9% (335). The mean dmf-s was 7.6 ± 9.7. The prevalence of non-cavitated lesions on at least one tooth surface was 73.4%. Cavitated lesions were more frequent on smooth surfaces than on occlusal surfaces (respectively 64.7% and 46.8%; p value < 0.001). Only 25.1% (112.5) of the children had no clinical signs of caries according to the ICDAS criteria. It was concluded that dental caries is a highly prevalent condition in this Colombian population, the main contributor being non-cavitated lesions. There was an association between caries and oral hygiene practices, such as the amount of toothpaste used, and also between caries and the occurrence of a previous dental visit (p value < 0.00). Eating habits constituted no statistically significant association.
  • Occurrence of Aggregatibacter actinomycetemcomitans in Brazilians with chronic periodontitis Periodontics

    Cortelli, José Roberto; Roman-Torres, Caio Vinícius Gonçalves; Aquino, Davi Romeiro; Franco, Gilson Cesar Nobre; Costa, Fernando Oliveira; Cortelli, Sheila Cavalca

    Resumo em Inglês:

    Studies have suggested that A. actinomycetemcomitans is involved in the aetiology of aggressive periodontitis as well as in chronic periodontitis. This study was aimed at elucidating the occurrence of A. actinomycetemcomitans in a Brazilian population with chronic periodontitis. A total of 555 (mean age 33.04 ± 12.45) individuals, living in two large areas of the São Paulo State, namely "Baixada Santista" and "Vale do Paraíba", and diagnosed with mild [180 (mean age 29.59 ± 10.94)], moderate [241 (mean age 31.18 ± 11.45)] or severe [134 (mean age 33.04 ± 12.45)] chronic periodontitis were enrolled in this survey. Clinical exams including measurements of Probing Depth, Clinical Attachment Loss, Plaque and Gingival indices and subgingival microbiological assessments were performed at all population. The genomic DNA of A. actinomycetemcomitans was identified by Polymerase Chain Reaction from periodontal pocket samples. The occurrence of A. actinomycetemcomitans among chronic periodontitis subjects as well as its association with age and gender were statistically analysed using the Chi-square and Odds Ratio tests. The significance of differences was established at 5% (p < 0.05). A. actinomycetemcomitans was detected in 102 (18.37%) individuals: 29 (16.11%) mild; 42 (17.42%) moderate; and 31 (23.13%) severe chronic periodontitis with no statistical difference among groups. A higher occurrence of the searched bacterium was found both in the youngest group (p < 0.05) as well as in the female group (p < 0.05). This study elucidated that A. actinomycetemcomitans harbored subgingival pockets of our target group of chronic periodontitis subjects and that this bacterium seems to be inversely related to age, but related to the female gender.
  • The ability of the BANA test to detect different levels of P. gingivalis, T. denticola and T. forsythia Periodontics

    Andrade, José Alexandre de; Feres, Magda; Figueiredo, Luciene Cristina de; Salvador, Sérgio Luiz; Cortelli, Sheila Cavalca

    Resumo em Inglês:

    The aim of this study was to evaluate the ability of the BANA Test to detect different levels of Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia or their combinations in subgingival samples at the initial diagnosis and after periodontal therapy. Periodontal sites with probing depths between 5-7 mm and clinical attachment level between 5-10 mm, from 53 subjects with chronic periodontitis, were sampled in four periods: initial diagnosis (T0), immediately (T1), 45 (T2) and 60 days (T3) after scaling and root planing. BANA Test and Checkerboard DNA-DNA hybridization identified red complex species in the subgingival biofilm. In all experimental periods, the highest frequencies of score 2 (Checkerboard DNA-DNA hybridization) for P. gingivalis, T. denticola and T. forsythia were observed when strong enzymatic activity (BANA) was present (p < 0.01). The best agreement was observed at initial diagnosis. The BANA Test sensitivity was 95.54% (T0), 65.18% (T1), 65.22% (T2) and 50.26% (T3). The specificity values were 12.24% (T0), 57.38% (T1), 46.27% (T2) and 53.48% (T3). The BANA Test is more effective for the detection of red complex pathogens when the bacterial levels are high, i.e. in the initial diagnosis of chronic periodontitis.
  • Tooth loss in individuals under periodontal maintenance therapy: prospective study Periodontics

    Lorentz, Telma Campos Medeiros; Cota, Luís Otávio Miranda; Cortelli, José Roberto; Vargas, Andréia Maria Duarte; Costa, Fernando Oliveira

    Resumo em Inglês:

    This prospective study aimed to evaluate the incidence, the underlying reasons, and the influence of predictors of risk for the occurrence of tooth loss (TL) in a program of Periodontal Maintenance Therapy (PMT). The sample was composed of 150 complier individuals diagnosed with chronic moderate-severe periodontitis who had finished active periodontal treatment and were incorporated in a program of PMT. Social, demographic, behavioral and biological variables were collected at quarterly recalls, over a 12-month period. The effect of predictors of risk of and confounding for the dependent variable TL was tested by univariate and multivariate analysis, as well as the underlying reasons and the types of teeth lost. During the monitoring period, there was a considerable improvement in periodontal clinical parameters, with a stability of periodontal status in the majority of individuals. Twenty-eight subjects (18.66%) had TL, totaling 47 lost teeth (1.4%). The underlying reasons for TL were: periodontal disease (n = 34, 72.3%), caries (n = 3, 6.4%), prosthetic reasons (n = 9, 19.2%), and endodontic reasons (n = 1, 2.1%). Additionally, subjects with 10% of sites with probing depth between 4 and 6 mm were 5 times more likely to present TL (OR = 5.13, 95% CI 2.04-12.09). In this study, the incidence of TL was small and limited to few individuals. Additionally, gender and severity of periodontitis were significantly associated with TL during the monitoring period.
  • Seal capability of interim post and core crown with temporary cements Prosthodontics

    Bönecker-Valverde, Guilherme; Maniglia-Ferreira, Claudio; Abi-Rached, Gisele Priscila; Gomes, Brenda Paula Figueiredo de Almeida; Mesquita, Marcelo Ferraz

    Resumo em Inglês:

    The purpose of the present study was to evaluate the in vitro seal capability of interim post and core crown restorations. Eighty teeth were selected and divided into 8 groups. Four experimental groups received interim posts and core crowns. Half of each group was decoronated at the cementum-enamel junction, groups PCCH and PCZO. The other half was sectioned 2 mm coronal to the cementum-enamel junction, groups PCrZO and PCrCH. The interim post and core crowns were luted with Rely X Temp NE, groups PCrZO and PCZO; Hydro C was used for Groups PCrCH and PCCH. The control groups, PC and PCr, received uncoated post and core crowns; groups OTg and OT were left without interim post and core crowns and were totally open. Infiltration was accessed by dye exposure followed by demineralization of the teeth. The length of the infiltration was measured using digital images taken from the specimens. The images were inserted into the Image Tool 3.0 software. Kruskal-Wallis analysis of variance and Dunn's multiple comparison method were used to test for significant differences among test groups (P < .05). Groups PCrZO and PCrCH showed the least dye penetration, followed by groups PCZO and PCCH. Teeth restored with interim post and core crowns will be subject to leakage. Ethics Committee: 095/2008.
  • Effect of curing mode on the hardness of dual-cured composite resin core build-up materials Restorative Dentistry

    Arrais, César Augusto Galvão; Kasaz, Aline de Cerqueira; Albino, Luís Gustavo Barrote; Rodrigues, José Augusto; Reis, Andre Figueiredo

    Resumo em Inglês:

    This study evaluated the Knoop Hardness (KHN) values of two dual-cured composite resin core build-up materials and one resin cement exposed to different curing conditions. Two dual-cured core build-up composite resins (LuxaCore®-Dual, DMG; and FluoroCore®2, Dentsply Caulk), and one dual-cured resin cement (Rely X ARC, 3M ESPE) were used in the present study. The composite materials were placed into a cylindrical matrix (2 mm in height and 3 mm in diameter), and the specimens thus produced were either light-activated for 40 s (Optilux 501, Demetron Kerr) or were allowed to self-cure for 10 min in the dark (n = 5). All specimens were then stored in humidity at 37°C for 24 h in the dark and were subjected to KHN analysis. The results were submitted to 2-way ANOVA and Tukey's post-hoc test at a pre-set alpha of 5%. All the light-activated groups exhibited higher KHN values than the self-cured ones (p = 0.00001), regardless of product. Among the self-cured groups, both composite resin core build-up materials showed higher KHN values than the dual-cured resin cement (p = 0.00001). LuxaCore®-Dual exhibited higher KHN values than FluoroCore®2 (p = 0.00001) when they were allowed to self-cure, while no significant differences in KHN values were observed among the light-activated products. The results suggest that dual-cured composite resin core build-up materials may be more reliable than dual-cured resin cements when curing light is not available.
  • Use of the plasma CTX for assessing the bone activity of the mandible among osteopenic and osteoporotic patients Oral Surgery

    Avolio, Glacio; Brandão, Cynthia; Marcucci, Marcelo; Alonso, Gilberto

    Resumo em Inglês:

    The aim of this study was to determine whether the plasma CTX bone remodeling marker is useful for indicating the bone metabolic activity level of the mandible. Thirty-six patients were selected; all were postmenopausal and aged 50 years or over. In accordance with the WHO criteria for osteoporosis, a control group was set up (n = 10) in which the T-score was greater than -1 and a diseased group with T-score less than -1. Using MDP-99mTc samples, the radioisotope uptake in the femoral neck (R2) and mandibular body (R1) was analyzed. A third examination was performed using the plasma CTX biochemical bone-modeling marker. The inferential results for the diseased group showed that Ln(R1) presented a statistically significant linear relationship with Ln(CTx) (p = 0.067) and with the T-score (p = 0.018). The plasma CTX bone remodeling marker is useful for monitoring the bone metabolic activity of the mandible.
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