26 research outputs found
Does comsumption of staining drinks compromise the result of tooth whitening?
After dental bleaching procedures dentists commonly advise patients to reduce the consumption of beverages that may cause the teeth to stain, however, the effectiveness of teeth whitening may not be directly affected by diet. It was evaluated through in vitro study whether contact with dyes through in-office bleaching sessions with 35% hydrogen peroxide would influence the effectiveness of treatment. Sixty bovine incisors were randomly assigned into 5 groups (n = 12) according to contact frequency and type of dye solutions. All dental elements received three in-office bleaching sessions with 35% hydrogen peroxide one week apart. Except for GCTRL (control), all experimental groups were submerged in dyes (coffee or wine) for 5 min once a day. In groups GC24 and GW24 contact with the dyes was made from 24 hours after each bleaching session, while in groups GC72 and GW72, from 72 hours. The color was measured with a digital spectrophotometer. Data were expressed as statistics: mean and standard deviation. Contact with dyes during in-office bleaching treatment with 35% hydrogen peroxide did not influence the staining averages after three bleaching sessions. The speed of the whitening effect was influenced by contact with coffee from 24 hours after the sessions and with wine from 24 hours and 72 hours after the whitening session. The whitening result was reversed after one week for all groups, especially for groups that came in contact with red wine either 24 hours or 72 hours after session and coffee after 24 hours. Contact with dyes during in-office bleaching treatment did not influence the final staining averages after three bleaching sessions although there was influence on speed of the whitening effect between the sessions
Color stability of Bulk-Fill composite restorations
The color stability of the composite resin is an important property that influences its clinical longevity, which remains an inherent challenge to the material. Thus, the purpose of this study was to evaluate the color stability of bulk-fill resins when exposed to dye. Cavities were prepared in 80 bovine incisors, which were randomly assigned into 4 groups (n = 20) according with the resin composite used: P60 (Control Group - Filtek P60, 3M/ESPE), FP (Filtek Bulk-Fill Posterior, 3M/ESPE), SDR (SDR, Dentsply) and FF (Filtek Bulk Fill Flow, 3M/ESPE). All restorations were performed according to the protocol of each manufacturer, the control group was restored using the incremental technique, and the other groups using single-increment technique. The color of each restoration was measured using a portable digital spectrophotometer (Easyshade-Vita) according to the CIELab system, and then the teeth were submerged in red wine for 07 days, kept in a biological oven at 37ºC. New color registration was performed to measure the ?E index of color variation. The P60 group had the lowest average ?E (16.96), while the FF group had the highest average (28.09) and ranged from 21.19 to 26.28 in the FP and SDR groups. Analysis of the color variation showed that the control group had better color stability than the Bulk-Fill resins evaluated
Dental Whitening: Self-Referred Needs versus Professional Indication
Objective: To analyze the self-reported need of patients compared to professional indications for tooth whitening. Material and Methods: Initially, 58 undergraduate students responded to a form that highlighted the question: "Do you think you need to have your teeth whitened?" Among those who answered positively to the previous question, ten individuals were photographed with their smiles. In addition, they were asked to point out, on the Vita 3D-Master scale, which color they believed their teeth had, a value that was compared to the actual color obtained by a spectrophotometer. Finally, the photographs were presented to dentists, who were asked about the indication or not of the whitening treatment. Results: Most interviewees (63.8%) self-reported the need for whitening, as well as there was a greater incidence of a positive indication among professionals (53.9%). Pearson's Chi-square test revealed a relationship between patient gender and the training course on the desire to have teeth whitened. Among the professionals, the specialty, as well as time since graduation, interfered in the indication for whitening. Conclusion: Professionals and patients share the aesthetic ideal directly related to light teeth; most patients self-perceive the color of their teeth darker than it actually is; the opinion about the color of the teeth has an extremely subjective character and varies greatly from one professional to another
Evaluation of marginal sealing quality of restorations with low shrinkage composite resins
This study compared the quality of marginal sealing in the gingival wall of class II preparations of two low-shirinkage resins of the bulk fill type with a conventional resin isolated or associated with a glass ionomer cement (GIC). 40 human molars wer
Influence of different thermopolymerization methods on composite resin microhardness
Background: Additional heat polymerization in composite resins allows greater effective ness of microhardness, flexural strength, fracture tough ness, wear resistance, and increased color stability.Material and Methods: 150 composite resin specimens were made using a 4 mm diameter and 2 mm thick bipartite steel matrix. Five resins composed of different compositions were tested (Brilliant Everglow/Coltene, Filtek One BulkFill/3M, Filtek P60/3M, Filtek Z350XT/3M, Filtek Z250XT/3M), and for each of them three types of polyme-rization were tested: light curing only (n=50); photopolymerization + autoclave thermopolymerization (n=50) and photopolymerization + microwave thermopolymerization (n=50). Each specimen was submitted to three indenta-tions by means of the Vickers microhardness test, applying a load of 300gf, associated with the time of 15s. Data were analyzed descriptively by means of statistics, standard deviation and coefficient of variation and inferentially by the F test (ANOVA) in the comparison between groups. The margin of error used in statistical test decisions was 5%.Results: The highest vicker microhardness averages were from the Control group (light curing only) on P60 (82.16) and Z250 XT (79.61) resins. The lowest averages were all verified on Brilliant Everglow resin in all polymerization methods studied: Photopolymerization (37.32), with microwave (43.80) and autoclave (45.12), followed by Bulk Fill 3M resin, ranged from 52.23 to 59.15.Conclusions: Both autoclave and microwave thermopolymerization methods showed similar behavior on the mi-crohardness of the composites studied. Considering the resin type, there was a varied behavior compared to thermo-polymerization, which increased the microhardness values for Brilliant Everglow resins (Coltene) and Filtek One Bulkfill (3M) and decreased for Filtek P60, Filtek Z350XT and Filtek Z250XT resins
Evaluation of Satisfaction of Adolescents Treated by Dental Students
Objective: To evaluate the satisfaction of adolescents undergoing dental treatment between 2016 and 2018 at the Dental School of the Federal University of Minas Gerais (FAO UFMG). Material and Methods: A descriptive cross-sectional study using the Oral Health Services Satisfaction Assessment Questionnaire (QASSaB). The structured questionnaire has eleven questions divided among the dimensions: dentist / patient relationship, relationship with other professionals, effectiveness, accessibility/availability, technical-scientific quality, cleanliness and physical environment, acceptability, effectiveness/resolution, each with five response options. Descriptive data analysis was performed using absolute and relative frequencies. Results: A total of 145 adolescents participated in this study, 60 males and 85 females; 74.85% of adolescents rated dental treatment received as excellent, 76.7% reported having no symptoms after treatment, 46.2% considered it easy/very easy to get treatment, 65.6% reported that waiting time was short/very short, 90% considered dental equipment modern/very modern, 98% regarded the cleanliness of the waiting room and bathrooms as being excellent, 83.4% reported that they always received an explanation about the treatment, and 51.57% were totally satisfied with the appearance of the treated teeth and their chewing capacity. Conclusion: It was possible to observe that the adolescents, users of FAO UFMG, were satisfied with the service in the studied dimensions: human relations, effectiveness, accessibility/availability, technical-scientific quality, physical environment/cleanliness, acceptability and resolvability/effectiveness
Evaluation of Satisfaction of Adolescents Treated by Dental Students
Objective: To evaluate the satisfaction of adolescents undergoing dental treatment between 2016 and 2018 at the Dental School of the Federal University of Minas Gerais (FAO UFMG). Material and Methods: A descriptive cross-sectional study using the Oral Health Services Satisfaction Assessment Questionnaire (QASSaB). The structured questionnaire has eleven questions divided among the dimensions: dentist / patient relationship, relationship with other professionals, effectiveness, accessibility/availability, technical-scientific quality, cleanliness and physical environment, acceptability, effectiveness/resolution, each with five response options. Descriptive data analysis was performed using absolute and relative frequencies. Results: A total of 145 adolescents participated in this study, 60 males and 85 females; 74.85% of adolescents rated dental treatment received as excellent, 76.7% reported having no symptoms after treatment, 46.2% considered it easy/very easy to get treatment, 65.6% reported that waiting time was short/very short, 90% considered dental equipment modern/very modern, 98% regarded the cleanliness of the waiting room and bathrooms as being excellent, 83.4% reported that they always received an explanation about the treatment, and 51.57% were totally satisfied with the appearance of the treated teeth and their chewing capacity. Conclusion: It was possible to observe that the adolescents, users of FAO UFMG, were satisfied with the service in the studied dimensions: human relations, effectiveness, accessibility/availability, technical-scientific quality, physical environment/cleanliness, acceptability and resolvability/effectiveness
Influence of different adhesion strategies on glass fiber post retention
Failures in glass fiber post (GFP) retention may be associated with low adhesion achieved in root dentin.55 single-rooted premolars were endodontically treated and distributed according to different adhesion strategies (n=11): G1: RelyX ARC (3M ESPE; etch-rinse strategy); G2: Relyx Ultimate (3M ESPE; etch-rinse strategy); G3: AllCem (FGM; etch-rinse strategy); G4: Relyx Ultimate (3M ESPE; self-etching strategy); G5: RelyX U200 (3M ESPE; self-adhesive strategy). For Bonding Strength (BS) analysis, the roots were sectioned in slices (1.0mm thickness) corresponding to each root third and submitted to push-out test. The type of failure was assessed by scanning electron microscopy (SEM).The highest BS averages were found in G2 and G3. However, in the middle and apical root thirds, G3 showed statistically similar results to G4 and G5. In the cervical and middle third, G1 was statistically similar to G4 and G5. The mixed type of failure was the most common in all groups.Self-etching (G4) and self-adhesive resin (G5) cements, showed similar BS results of immediate bonding in the cementation of GFP compared to conventional resin cements (G1, G2, G3)
Structural characterization of a novel peptide with antimicrobial activity from the venom gland of the scorpion Tityus stigmurus: Stigmurin
AbstractA new antimicrobial peptide, herein named Stigmurin, was selected based on a transcriptomic analysis of the Brazilian yellow scorpion Tityus stigmurus venom gland, an underexplored source for toxic peptides with possible biotechnological applications. Stigmurin was investigated in silico, by circular dichroism (CD) spectroscopy, and in vitro. The CD spectra suggested that this peptide interacts with membranes, changing its conformation in the presence of an amphipathic environment, with predominance of random coil and beta-sheet structures. Stigmurin exhibited antibacterial and antifungal activity, with minimal inhibitory concentrations ranging from 8.7 to 69.5μM. It was also showed that Stigmurin is toxic against SiHa and Vero E6 cell lines. The results suggest that Stigmurin can be considered a potential anti-infective drug
Práticas Educomunicativas
Esta publicação pretende divulgar as práticas educomunicativas realizadas em diferentes regiões do país e que estão sendo implantadas por nossos associados. O e-book Práticas Educomunicativas, que visa oferecer um material de uso prático que possa servir de apoio pedagógico em diferentes contextos, escolar ou de ações junto a instituições, apresenta 20 artigos de profissionais e pesquisadores que implementam ações que inter-relacionam comunicação e educação no contexto da educação apontando as experiências e processos de educomunicação e valorizando desta forma, o trabalho realizado por cada educomunicador oferecendo, ao leitor, um material de uso prático que possa servir de apoio pedagógico em diferentes contextos