Cementation of fiber post: influence of the cement insertion techniques on the bond strength of the fiber post-root dentin and the quality of the cement layer.

The aim of this study was to assess the influence of resin cement insertion methods on the bond strength of a fiber post to root dentin and quality of the cement layer. Forty bovine single-roots (length =16 mm) were randomly allocated into four groups, according to the cement insertion methods (N.=10): Gr1- Lentulo drill #40, Gr2- Centrix syringe, Gr3- Explorer #5, Gr4- fiber post. The root canals were prepared at 12 mm, using preparation bur # 3 of a cylinder quartz-FRC post (Aesthet post-plus, Bisco). The fiber posts were cemented using a multi-step etch-and-rinse adhesive system (All Bond 2®, Bisco) and a dual-cured resin cement (Duolink, Bisco). Each root was cut into seven samples: four samples of 1.8 mm thickness for push-out testing, and three with 0.5 mm for cement layer quality analyzing. One-way ANOVA was used for the push-out test values and the One-Way Kruskal-Wallis (P<0.05) and Dunn (10%) tests for the cement layer analyzes. ANOVA showed that the cement layer quality was affected by the cement insertion methods (P=0.0044): Gr1 (3.8 ± 1.3a), Gr2 (3.2 ± 1.3a), Gr3 (5.2 ± 1.5a,b) and Gr4 (5.2 ± 1.5b) (Dunn test), whereas the bond strength (MPa) was not affected by cement insertion methods: G1 (4.2 ± 1.3), G2 (3.2 ± 1.8), G3 (4.5 ± 0.9), G4 (3.1 ± 1.3). The fiber posts should be cemented with the assistance of the lentulo drill or centrix syringe to promote the best cement layer results.

Evaluation of the dentin-pulp complex after cavity preparation with ultrasonic diamond tip

The aim of this paper was to compare the dentin-pulp complex response to cavity preparation in human teeth using ultrasonic chemical vapor deposition (CVD) diamond tip and high-speed diamond bur. Class V buccal cavities were randomly prepared in 40 premolars from 14 patients aged 11 to 15 years. The cutting time was recorded and the cavities had the axial walls protected with gutta-percha and were filled with glass ionomer cement. The teeth were extracted at intervals of 0, 5, 10 and 20 days, and were decalcified, sectioned and stained by Hematoxylin & Eosin, Masson's Trichrome and Brown & Brenn techniques. The inflammatory response and cell disorganization were blindly evaluated by two examiners. The remaining dentin thickness (RDT) was measured by a linear scale using computer software. Statistical analysis by one-way ANOVA showed no statistically significant difference (P≤0.05) among the cavities prepared with either type of instrument, with mean RDT of 1132.50 mm. Cutting time and the pulp-dentin complex responses were analyzed statistically by Kruskal-Wallis and Dunn tests (P≤0.05). The ultrasonic CVD diamond tip took 5 times longer to prepare the cavities and there were no typical inflammatory pulp responses in cavities prepared with either type of cutting instrument, only mild to moderate cell disorganization was present. Even taking longer to cut the dental substrate, the ultrasonic CVD diamond tip produced similar pulp response compared to the conventional high-speed diamond bur.

Silica coating on alumina ceramic: comparison of three chairside air-abrasion devices working for different times and distances.

This study evaluated, by scanning electron microscope (SEM) and EDS, the effect of different strategies for silica coating (sandblasters, time and distance) of a glass-infiltrated ceramic (In-Ceram Alumina). Forty-one ceramic blocks were produced. For comparison of the three air-abrasion devices, 15 ceramic samples were divided in three groups (N.=5): Bioart, Microetcher and Ronvig (air-abrasion parameters: 20 s at a distance of 10 mm). For evaluation of the time and distance factors, ceramic samples (N.=5) were allocated in groups considering three applied times (5 s, 13 s and 20 s) and two distances (10 mm and 20 mm), using the Ronvig device. In a control sample, no surface treatment was performed. After that, the micro-morphologic analyzes of the ceramic surfaces were made using SEM. EDS analyzes were carried out to detect the % of silica on representative ceramic surface. ANOVA and Tukey tests were used to analyze the results. One-way ANOVA showed the silica deposition was different for different devices (P=0.0054). The Ronvig device promoted the highest silica coating compared to the other devices (Tukey test). Two-way ANOVA showed the distance and time factors did not affect significantly the silica deposition (application time and distance showed no statistical difference). The Ronvig device provided the most effective silica deposition on glass-infiltrated alumina ceramic surface and the studied time and distance for air-abrasion did not affect the silica coating.

Adhesion between fiber post and root dentin: evaluation of post surface conditioning for bond strength improvement.

The aim of this paper was to evaluate two surface conditioning methods associated with the application of adhesive on the post surface for improving the bond to resin cement. Sixty single-rooted bovine teeth were sectioned at 16 mm in length, prepared (9 mm depth), embedded in a PVC cylinder using acrylic resin, and allocated into 3 groups (N.=20) according to post surface treatment: cleaning with ethanol (control group); etching with hydrogen peroxide; etching with hydrofluoric acid. Ten posts for each group were silanized and other 10 posts were silanized and received an adhesive agent. The posts were cemented with self-adhesive resin cement (RelyX U100 resin cement). All teeth were sectioned perpendicularly to the long axis (2 mm thickness per slice), submitted to push out bond strength testing and the type of failure was recorded. The obtained data were submitted to two-way ANOVA and Turkey's test, with the level of significance set at 5%. Neither the hydrofluoric acid or hydrogen peroxide post surface treatment, nor the adhesive application, had an influence on bond strength values. The main type of failure was adhesive between cement and dentin. Etching and the application of an adhesive on the post surface did not presented a significant influence on the bond strength results for the fiber post resin cement-root dentin assembly. The cement appears to adhere very well to the fiber post surface rather than the dentin surface.

Biaxial flexural strength of CAD/CAM ceramics.

Aim of the study was to evaluate the biaxial flexural strength of ceramics processed using the Cerec inLab system. The hypothesis was that the flexural strength would be influenced by the type of ceramic. Ten samples (ISO 6872) of each ceramic (N.=50/n.=10) were made using Cerec inLab (software Cerec 3D) (Ø:15 mm, thickness: 1.2 mm). Three silica-based ceramics (Vita Mark II [VM], ProCad [PC] and e-max CAD ECAD]) and two yttria-stabilized tetragonal-zirconia-polycrystalline ceramics (Y-TZP) (e-max ZirCad [ZrCAD] and Vita In-Ceram 2000 YZ Cubes [VYZ]) were tested. The samples were finished with wet silicone carbide papers up to 1200-grit and polished in a polishing machine with diamond paste (3 μm). The samples were then submitted to biaxial flexural strength testing in a universal testing machine (EMIC), 1 mm/min. The data (MPa) were analyzed using the Kruskal-Wallis and Dunn (5%) tests. Scanning electronic microscopy (SEM) was performed on a representative sample from each group. The values (median, mean±sd) obtained for the experimental groups were: VM (101.7, 102.1±13.65 MPa), PC (165.2, 160±34.7 MPa), ECAD (437.2, 416.1±50.1 MPa), ZrCAD (804.2, 800.8±64.47 MPa) and VYZ (792.7, 807±100.7 MPa). The type of ceramic influenced the flexural strength values (P=0.0001). The ceramics ECADa, e-max ZrCADa and VYZa presented similar flexural strength values which were significantly higher than the other groups (PCb and VM IIb), which were similar statistically between them (Dunn's test). The hypothesis was accepted. The polycrystalline ceramics (Y-TZP) should be material chosen for make FPDs because of their higher flexural strength values.

Anaerobic effluent disinfected with ozone/hydrogen peroxide efluente anaeróbio desinfetado com ozônio/peróxido de hidrogênio

This research aimed at studying the oxidation process, to verify the effectiveness of coliform inactivation and to evaluate the formation of ozonation disinfection byproducts (DBP) in anoxic sanitary wastewater treated with ozone/hydrogen peroxide applied at doses of 2.6 mg O3 L-1 and 2.0 mg H2O2 L-1 with contact time of 10 min and 8.1 mg O3 L-1 and 8.0 mg H2O2 L-1 with contact time of 20 min. The mean chemical oxygen demand (COD) reductions were 7.50 and 9.40% for applied dosages of 2.5-2.8 and 6.4-9.4 mg O3 L-1 + 2.0 and 8.0 mg H2O2.L-1, respectively. The Escherichia coli (E. coli) inactivation range was 2.98-4.04 log10 and the total coliform inactivation range was 2.77-4.01 log10. The aldehydes investigated were formaldehyde, acetaldehyde, glyoxal and methylglyoxal. It was observed only the formation of acetaldehyde that ranged 5.53 to 29.68 μg L-1.

Cephalometric evaluation of hyoid bone position in a patient with Down syndrome: Case report

The hyoid bone contributes to the maintenance of the airway, chewing and swallowing, given to its anatomical and functional relations to the craniocervical complex. Cephalometric analysis has great importance for orthopedics, orthodontics and oral maxillary surgery. For the treatment of patients with special care needs, the cephalometric evaluation of the position of the hyoid bone should also contribute as a complementary element for dental diagnosis and the selection of the adequate treatment. The aim of this paper is to demonstrate the alteration of the hyoid position after carrying out the functional orthopedic maxillary treatment in a 9 year-old patient with Down Syndrome. Initial cephalometric analysis revealed inadequate position of hyoid bone. The association of speech therapy to dynamic functional rehabilitation of jaws showed a positive effect in occlusal relation and facial expression. After treatment, all dimensions obtained from the hyoid triangle were higher than initial ones, except the anterior-posterior value of C3-H, which suggested function improvement of stomatognathic system. Once considered its anatomical and physiological relationship with the others structures of the stomatognathic system, cephalometric analysis of hyoid bone position was helpful to the comprehension of the craniofacial abnormalities related to chromosomal anomaly, and thus is essential to the interdisciplinary dialogue.

Influence of cutting instruments and adhesive systems on hybrid layer formation.

Influence of cutting instruments and The aim of this study was to analyze the hybrid layer in noncarious dentin prepared by different cutting instruments and restored with composite resin. The cavities were randomly prepared in 40 specimens using a high-speed diamond bur (KG Sorensen 1013) and an ultrasonic tip (CVDentus C22). The cavities were restored with composite resin by varying the adhesive system between the Adper™ Single Bond (2 x 1 system, primer+adhesive) and the Prompt L-Pop™ (3 x 1 system, self-etching). The restorations were hemisected longitudinally and analyzed in the SEM (Scanning electron microscopy) in order to evaluate the hybrid layer and resinous tags characteristics, using scores ranging from 1 to 6. The Pearson test revealed a high correlation coefficient and good significance levels for both intra- and inter-raters values (r=0.90). The data were statistically analyzed using the Mann-Whitney test (P≤0.05). A larger proportion of regular hybrid layers with numerous tags were observed in the dentin prepared using the high-speed diamond burs and restored with a 2 × 1 adhesive system. Alternatively, the 3 × 1 adhesive system promoted the generation of a thin hybrid layer with few tags. After preparation using an ultrasonic tip revealed few or no tags after the preparation and 2 × 1 or 3 × 1 adhesive system application. The high-speed diamond burs produced a dentin surface that was more favorable to restorative material adhesion than the ultrasonic tips, regardless of the adhesive system used.

Drug-induced gingival overgrowth: A clinical and histopathological report

Gingival overgrowth is a significant problem faced by periodontists and is particularly associated with the use of certain drugs such as nifedipine, a high-specificity calcium channel blocker used for the treatment and prophylaxis of certain cardiovascular diseases. Development of gingival overgrowth is characterized by increased collagen in gingival tissue. In general is asymptomatic, at times associated with spontaneous bleeding and ulceration and can promote aesthetic changes and compromise hygiene habits and mastication of the patient. The severity of the symptoms is associated with the presence of risk factors such association with other drugs. This paper aims to present a case report of a patient with generalized gingival overgrowth, with more severe characteristics in the anterior mandible induced by chronic use of nifedipine who underwent basic non-surgical periodontal treatment including supra and subgingival scaling and root planning in both jaws associated with rigorous oral hygiene instructions and surgical therapy in the anterior mandible, the most affected area, to remove the excess of gingival tissue. Nifedipine was replaced by the patient cardiologist to propanolol hydrochloride (40 mg/kg) in an attempt to minimize unwanted side effects. After 6 month follow-up, no recurrence was observed, oral hygiene had improved and the patient had clinical periodontal health and esthetic satisfaction.

Speech therapy intervention before dental management in patients with special needs: A case report

Fragile X syndrome is a cytogenetic abnormality related to chromosomal X. This syndrome is frequently associated to intellectual disability, psychological problems, as well as heart, skeletal and join alterations. Intraoral anomalies include malloclusion, ogival palate, cleft palate, presence of mesiodens, dental hypomineralization and abrasion of the occlusal surfaces and incisai edges. The study of characteristics of this syndrome is important for the dentist in order to guide dental treatment and prevention. The aim of this study is to present a myofunctional therapy protocol, evaluated by surface electromyography. A case of a 21 year-old young man who attended the Training Program in Dentistry for Persons with Disabilities, School of Dentistry of São José dos Campos/UNESP is reported. He underwent myofunctional therapy before dental treatment and the masticatory muscles were evaluated by surface electromyography. The exercises of myofunctional therapy consisted of active and passive simple movements of opening and closing the mouth, tongue protrusion and retrusion, digital manipulation and also by using an electric massager on intraoral and perioral region of the masseter, buccinator and orbicularis oris. Action potentials of the masticatory muscles decreased in almost all the muscles and values for the bite force and mandibular opening capacity increased. This study showed that brief and immediate myofunctional therapy optimized clinical practice with positive repercussion on dental care.

Endurance training does not change the relative intensity at lactate threshold in elderly

Aim. The aim of the study was to verify whether endurance training may induce changes on the percentage of peak heart rate (% peak HR) at the lactate threshold (LT) intensity in untrained elderly. Methods. Sixteen healthy men (64.3 ± 4.1 yrs) underwent an incremental test on cycloergometer to determine the LT and the corresponding % peak HR at LT intensity. Afterwards, they were randomly distributed into two groups (n = 8 each): endurance training (ET) and control (C). The ET exercised 3 days a week for 12 weeks. The training session was divided into warm-up (5 min at 50% of LT;), a main part, and a cool-down (5 min 50% below of LT). The main part had a gradual increased volume through the weeks of 2 min. The initial volume on the 1st week was 25 min reaching 47 min at the 12th week. The relative intensity was kept constant (90 to 100% of LT). Results. After 12 weeks, the % peak HR at LT did not change significantly for both groups P > 0.05 (ET 82.9 ± 4.1 vs. 82.5 ± 3.4 and Ç 80.2 ± 7.1 vs. 81.8 ± 7.1). Conclusion. We conclude that endurance training proposed does not change the relative intensity at LT in elderly.

Caracterização de efluentes de viveiros de engorda de rã-touro (lithobates catesbeianus, Shaw, 1802)

Aim: Current analysis characterizes the effluent from bullfrog-rearing ponds during the grow-out phase; Methods: Temperature, pH, dissolved oxygen, electric conductivity, turbidity, total phosphorus, N-NH3, N-NO3, BOD5 and COD and the number of thermotolerant coliforms (Escherichia coli) of the inlet and outlet water of the ponds were analyzed twice a week. Assay consisted of a completely randomized experimental design with two treatments (inlet and outlet water) and six repetitions in a split-plot, coupled to collection over time as subplot; Results: All variables were significantly different (p < 0.05) between treatments and over time (p < 0.05). Average rates of temperature, pH and dissolved oxygen levels of the supply water were higher when compared to those of the effluent. The other variables such as conductivity, turbidity, total phosphorus, ammonia, nitrate, biological oxygen demand, chemical oxygen demand and E. coli were higher in the effluent when compared to rates in the supply water; Conclusions: The management during grow-out phase caused the deterioration of the water quality, with increasing levels of dissolved nutrients and the number of thermotolerant coliform. Ammonia and phosphorus levels in the effluent, caused by waste food, skin and feces, accelerate the eutrophication process of the receiving water body. Further studies on effluent treatment are required.

Eigenvalue analyses for non-transposed three-phase transmission line considering non-implicit ground wires

This paper presents a method for analyzing electromagnetic transients using real transformation matrices in three-phase systems considering the presence of ground wires. So, for the Z and Y matrices that represent the transmission line, the characteristics of ground wires are not implied in the values related to the phases. A first approach uses a real transformation matrix for the entire frequency range considered in this case. This transformation matrix is an approximation to the exact transformation matrix. For those elements related to the phases of the considered system, the transformation matrix is composed of the elements of Clarke's matrix. In part related to the ground wires, the elements of the transformation matrix must establish a relationship with the elements of the phases considering the establishment of a single homopolar reference in the mode domain. In the case of three-phase lines with the presence of two ground wires, it is unable to get the full diagonalization of the matrices Z and Y in the mode domain. This leads to the second proposal for the composition of real transformation matrix: obtain such transformation matrix from the multiplication of two real and constant matrices. In this case, the inclusion of a second matrix had the objective to minimize errors from the first proposal for the composition of the transformation matrix mentioned. © 2012 IEEE.

Piscicultura e manejo da qualidade da água

Fish farms' water quality management is analyzed with regard to the management employed and the different trophic states are compared within the system during the dry and rainy seasons. Six sites were marked two in the water supply (P1 and P2), and four within the fish farm (P3 to P6). Whereas sites P1 and P2 (water supply) were characterized as oligotrophic, the others were mesotrophic and eutrotrophic sites. Environmental variables, mainly nutrients, conductivity, COD, BOD5 and TSS tended to increase as from P3 due to management and fertilization. Greater impact has been registered in the fish farm under analysis for variables COD, ammonia, total phosphorus and TSS during the discharge and pond emptying period. Frequent monitoring of water quality should be undertaken in fish breeding and plankton production ponds, especially in those close to P3 and P4. Removal of sediment in decantation lake or P5 is also recommended to decrease nutrient concentrations, especially phosphorus, accumulated on the bottom soil.

Effects of intensification of the amazon river prawn, macrobrachium amazonicum, grow-out on effluent quality

Studies to determine suitable levels of intensification are essential for developing sustainable aquaculture. The objective of this study was to evaluate the quality of effluents discharged from ponds stocked with 10 (D10), 20 (D20), 40 (D40), and 80 (D80) postlarvae of Macrobrachium amazonicum/m2. Intake and effluent water samples were taken throughout a 5.5-mo grow-out cycle. In that study, twelve 0.01-ha earthen ponds were stocked postlarvae with 0.01g. Average water exchange rate was 15%/d; water was discharged from the bottom of the ponds. Prawns were fed a commercial feed with 38% crude protein according to their biomass (3-10%) and the concentration of dissolved oxygen (DO). In our research, temperature, turbidity, total suspended solids, conductivity, DO, pH, biochemical oxygen demand (BOD), chemical oxygen demand (COD), N-ammonia, N-nitrite, N-nitrate, N-Kjeldahl nitrogen, total phosphorus, and soluble orthophosphate were measured every 15d throughout the experiment in the early morning (0630 to 0730h). Turbidity was lower in D10 than in D20 and D40 and total phosphorus was higher in D80 than in D10 and D20. An analysis of principal components comparing treatments and intake water showed three groups: intake, D10 and a cluster of D20, D40, and D80. On the basis of the water characteristics found in our study it appears that the farming of M. amazonicum is likely to have a low environmental impact, at least up to a stocking density of 80prawns/m2. © by the World Aquaculture Society 2013.