Volumetric microleakage assessment of glass-ionomer-resin composite hybrid materials

Objective: This study was intended to quantify the marginal leakage of three glass-ionomer-resin composite hybrid materials and compare it with the leakage exhibited by a glass-ionomer cement and a bonded resin composite system. Method and materials: Standardized Class V cavities were prepared on root surfaces of 105 extracted human teeth, randomly assigned to five groups of 21 each, and restored with either Ketac-Fil Aplicap, Z100/Scotchbond Multi-Purpose Plus, Vitremer, Photac-Fil Aplicap, or Dyract. The teeth were thermally stressed for 500 cycles and stained with methylene blue. The microleakage was quantified spectrophotometrically, and the data were statistically analyzed with Friedman's test. Results: There were no significant differences in microleakage among the five groups. Restorations of all tested materials showed some marginal leakage in Class V cavities. Conclusion: The microleakage performance of glass-ionomer-resin composite hybrid materials was similar to those of a conventional glass-ionomer and a bonded resin composite system.

Desenvolvimento, otimização e caracterização física de um novo sistema multi-sensores de Biosusceptometria de Corrente Alternada (BAC) para obtenção de imagens biomagnéticas

A novel AC Biosusceptometry (ACB) system with thirteen sensors it was implemented and characterized in vitro using magnetic phantoms. The system presenting coils in a coaxial arrangement with one pair of excitation coil outside and thirteen pairs of detection coils inside. A first-order gradiometric configuration was utilized for optimal detection of magnetic signals. Several physical parameters such as baseline, number of turns, excitation field and diameters were studied for improvement of the signal/noise ratio. This system exhibits an enhanced sensitivity and spatial resolution, due to the higher density of sensors/area. In the future those characteristics will turn possible to obtain images of magnetic marker or tracer in the gastrointestinal tract focusing on physiological and pharmaceutical studies. ACB emerged due to its interesting nature, noninvasiveness and low cost to investigate gastrointestinal parameters and this system can contribute for more accurate interpretation of biomedical signals and images

Citotoxicidade de cimentos retrobturados experimentais em fibroblastos V79: [recurso eletrônico]

Combining the characteristics of good adhesion and sealing of the AH Plus sealer the biological properties of the MTA, zinc oxide and calcium hydroxide, the purpose of this study was to evaluate the cytotoxicity of these associations. The specimens of the sealers and their associations were mixed and exposure to culture medium (82.4 mm2surface/mL) after the manipulation and incubated in a humidified incubator (37°C and 100% humidity) for 24 h. Chinese hamster lung fibroblasts (V79) were exposed to different dilutions of this extracts for 24 h and cell viability was measured by MTT test. The differences between the cell survival rates were statistically analyzed for Kruskal-Wallis and Dunn (p≤0.05). All sealers showed a significant difference with the group control, except the MTA. Cytotoxicity with the control group increased in the following order: AH Plus < AH Plus + Ca(OH) 2 < AH Plus + OxZn< AH Plus + MTA < MTA (p≤ 0,05). It was concluded that the addition of biological materials in order to improve the consistency of AH Plus for use in retro cavities its toxicity has not decreased significantly

Endoscopia do trato gastrointestinal de cães e gatos

Endoscopy of the gastrointestinal tract is a specialized minimally invasive diagnostic method and with both diagnostic and therapeutic possibilities. It is divided into two major groups, the rigid and flexible endoscopy. The first most widely used for visualization of body cavities that do not have a light, like the chest, for example, and the second for those with light as the gastrointestinal tract. In Brazil there are few professionals, veterinary hospitals or clinics that offer this type of service. Thus, endoscopy is an area of expertise of the veterinarian who is in huge expansion and has shown great applicability with excellent results in both clinical medicine and surgical small animals

Avaliação da integração de implantes de silicone com superfícies lisa, texturizada e de poliuretano em cavidades anoftálmicas evisceradas de coelhos

Pós-graduação em Bases Gerais da Cirurgia - FMB

Resistência de união e microinfiltração em restaurações de resina

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efecto del blanqueamiento dental con peroxido de hidrógeno al 35% en la resistencia de unión de dientes restaurados con resina compuesta

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Immediate human pulp response to ethanol-wet bonding technique

To evaluate the short-term response of human pulps to ethanol-wet bonding technique. Methods Deep class V cavities were prepared on 17 sound premolars and divided into three groups. After acid-etching, the cavities from groups 1 (G1) and 2 (G2) were filled with 100% ethanol or distilled water, respectively, for 60 s before the application of Single Bond 2. In group 3 (G3, control), the cavity floor was lined with calcium hydroxide before etching and bonding. All cavities were restored with resin composite. Two teeth were used as intact control. The teeth were extracted 48 h after the clinical procedures. From each tooth serial sections were obtained and stained with haematoxylin and eosin (H/E) and Masson's trichrome. Bacteria microleakage was assessed using Brown & Brenn. All sections were blindly evaluated for five histological features. Results Mean remaining dentine thickness was 463 ± 65 μm (G1); 425 ± 184 μm (G2); and 348 ± 194 μm (G3). Similar pulp reactions followed ethanol- or water-wet bonding techniques. Slight inflammatory responses and disruption of the odontoblast layer related to the cavity floor were seen in all groups. Stained bacteria were not detected in any cavities. Normal pulp tissue was observed in G3 except for one case. Conclusions After 48 h, ethanol-wet bonding does not increase pulpal damage compared to water-wet bonding technique. Clinical significance Ethanol-wet bonding may increase resin-dentine bond durability. This study reported the in vivo response of human pulp tissue when 100% ethanol was applied previously to an etch-and-rinse simplified adhesive system.

Efeito de um gel de peróxido de carbamida a 10% sobre a resistência de união de restaurações adesivas à dentina

The present study aimed to analyze the effects of tooth bleaching with 10% carbamide peroxide (CP) gel on the bond strength of resin composite restorations to dentin. Material and Methods: Twenty cavities were prepared on the buccal surface of bovine teeth. After acid etching and application of bonding agent on dentin and enamel, the cavities were restored with composite resin. The specimens were divided into groups according to treatment on the surface of enamel / restoration: G1 - control (no treatment) and G2 (10% PC gel application for 8h/day during 14 days). After this period, the teeth were cut to produce beams with 0.81 mm2 cross-sectional area, which were subjected to microtensile test. The fractures were examined with a stereomicroscope and classified as cohesive in resin or dentin, adhesive, or mixed. Results: The statistical analysis (ANOVA / χ2) revealed that the factor treatment interfered with the bond strength, which was significantly higher for specimens of G2 (p <0.05). Adhesive fractures occurred in most of specimens of both groups with values ranging from 48.3% to 75%. Mixed fractures were the second more frequent in G1 and cohesive resin failure in G2. Conclusion: It was concluded that tooth bleaching with 10% of PC increased the bond strength of adhesive restorations to dentin.

Efeitos de diferentes sistemas de clareamento dental sobre a rugosidade e morfologia superficial do esmalte e de uma resina composta restauradora

The aim of this study was to evaluate and compare the roughness and superficial morphology of enamel and a composite restorative resin after different bleaching techniques application. Material and Methods: Bovine incisors were selected and standardized cavities were prepared on the buccal surface, which were restored with composite resin. The teeth were distributed according to the following treatments: G1- bleaching with 10% carbamide peroxide (CP); G2 - bleaching with 38% hydrogen peroxide (HP); and G3 - bleaching with 38% of HP associated to light irradiation. For G1, the bleaching gel was applied for 8 hours daily during 21 days. For G2 and G3, 3 sessions were performed, consisting of 3 applications of 15 minutes each, with 7 days of intervals between the sessions. For G3, the LED (470nm) light was used to activate the bleaching agent for 6 minutes. The surface of enamel and composite resin were evaluated before and after the bleaching procedures using a roughness tester and an atomic force microscope. Results: The results showed significant differences in surface roughness of enamel after bleaching only for G1 (Wilcoxon, p<0.05). For composite resin, neither group showed a statistical difference compared to control (Mann-Whitney, p>0.05). Conclusion: It was concluded that the increase in the roughness of enamel occurred only after bleaching therapy using a gel with 10% of CP. The bleaching procedures evaluated in this investigation did not increase the roughness or cause changes in the superficial morphology of the composite resin.

Adaptação marginal do agregado de trióxido mineral com e sem cloreto de cálcio em retrocavidades

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Análise comparativa da rugosidade superficial de resinas compostas de alta densidade

The success achieved by the use of composite resins in anterior teeth precipitately leads their use in posterior teeth. However, the indiscriminate application of these materials in cavities with several diverse sizes rapidly pointed out their lack of resistance to oclusal and proximal wear. OBJECTIVE: To evaluate the surface roughness of composite resin in relation to finishing and polishing technique. MATERIAL AND METHODS: Eight experimental groups (n = 15) were divided according to finishing and polishing technique: G1 – Z250TM composite resin without surface finishing and polishing; G2 – Z250TM composite resin plus surface finishing and polishing; G3 – P60TM composite resin without surface finishing and polishing; G4 – P60TM composite resin plus surface finishing and polishing; G5 – Prodigy CondensableTM composite resin without surface finishing and polishing; G6 – Prodigy CondensableTM composite resin plus surface finishing and polishing; G7 – SurefillTM composite resin without surface finishing and polishing; G8 – SurefillTM composite resin plus surface finishing and polishing. Three packable and one microhybrid (control group) composite resin was used. The surface roughness was measured using a profilometer at three points in each sample. The results were evaluated by ANOVA and Tukey test (p < 0.05). RESULTS: Prodigy CondensableTM composite resin showed the lowest surface roughness, while SurefillTM showed the highest surface roughness. Comparing the resins used, only between P60TM and SurefillTM there were no statistically significant differences (p > 0,05). CONCLUSION: Surface roughness was lower in all types of resin composites surfaces in contact with Mylar matrix strip than in areas submitted to finishing and polishing procedure.

Cuspal movement related to different polymerization protocols

Objective: The aim of this study to investigate the effects of different polymerization protocols on the cuspal movement in class II composite restorations. Materials and methods: Human premolar teeth were prepared with class II cavities and then restored with composite and three-step and two-step etch-and-rinse adhesive systems under different curing techniques (n = 10). It was used a lightemittingdiode curing unit and the mode of polymerization were: standard (exposure for 40 seconds at 700 mW/cm2), pulse-delay (initial exposure for 6 seconds at 350 mW/cm2 followed by a resting period of 3 minutes and a final exposure of 37 seconds at 700 mW/cm2) and soft-start curing (exposure 10 seconds at 350 mW/cm2 and 35 seconds at 700 mW/cm2). The cuspal distance (µm) was measured before and after the restorative procedure and the difference was recorded as cuspal movement. The data were submitted to two-way ANOVA and Bonferroni test (p < 0.05). Results: The type of adhesive system did not influenced the cuspal movement for all the curing methods. Standard protocol showed the highest values of cuspal movement and was statistically different from the pulse-delay and soft-start curing modes. Conclusion: Although the cuspal displacement was not completely avoided, alternative methods of photocuring should be considered to minimize the clinical consequences of composites contraction stress.

Application of Er:YAG and Er, Cr:YSGG lasers in cavity preparation for dental tissues: a literature review

The laser has been widely used in many specialties of dentistry and several wavelengths have been investigated as a substitute for high-speed handpiece. The purpose of this paper is to review the literature about the use of Er:YAG and Er,Cr:YSGG lasers in cavity preparation for dental tissues. Despite the differences in wavelength, pulse duration and energy, the morphological characteristics of the irradiated dentin surface with these lasers are comparable, as well as its effects as methods of dental caries prevention. Thus, Er:YAG and Er,Cr:YSGG lasers prepared cavities with similar effects on the dental tissue, however, further investigations about ideal irradiation conditions are needed for both lasers.

Pimenta pseudocaryophyllus (Gomes) L. R. Landrum (Myrtaceae): stem and leaf anatomy of a medicinal plant

Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPq)