Clinical and molecular overview of immunotherapeutic approaches for malignant skin melanoma: Past, present and future.

Traditional therapeutic approaches for malignant melanoma, have proved to be limited and/or ineffective, especially with respect to their role in improving patient survival and tumor recurrence. In this regard, immunotherapy has been demonstrated to be a promising therapeutic alternative, boosting antitumor responses through the modulation of cell signaling pathways involved in the effector mechanisms of the immune system, particularly, the so-called "immunological checkpoints". Clinical studies on the efficacy and safety of immunotherapeutic regimens, alone or in combination with other antitumor approaches, have increased dramatically in recent decades, with very encouraging results. Hence, this review will discuss the current immunotherapeutic regimens used to treat malignant melanoma, as well as the molecular and cellular mechanisms involved. In addition, current clinical studies that have investigated the use, efficacy, and adverse events of immunotherapy in melanoma will also be discussed.

First report of fungal meningoencephalitis by Penicillium chrysogenum in Brazil.

INTRODUCTION: Fungal infections of the central nervous system present a variety of clinical syndromes, such as meningitis, encephalitis, raised intracranial pressure with a nonspecific presentation, and, in the last two decades, have increased the incidence of these fungal infections. Fungal meningoencephalitis is frequently associated with Cryptococcus, but this report stands out for presenting one species of Penicillium genus. OBJECTIVES: Here, we present the first case of meningoencephalitis associated with brain injury caused by Penicillium chrysogenum, in a patient who is immunocompetent and was admitted to Hospital Naval Marcílio Dias, Rio de Janeiro, Brazil. METHODS: To identify the fungal species, we performed phenotypic and genotypic methodologies, from the culture to the sequencing of internal transcribed spacer region, and ß-tubulin gene, a rare fungus in cerebrospinal fluid cultures, belonging to the genus Penicillium, was identified. CONCLUSION: We highlight the importance of the first report of meningoencephalitis caused by P. chrysogenum in a patient who is immunocompetent, registered in Brazil. We also emphasize the need for further studies to determine an effective treatment with the least possible side effects for patients infected by fungi that are rarely related to the most severe forms of invasive infections.

Influence of pH-cycling and abrasion wear on the mechanical properties of conventional and bulk fill resin composites

The objective of this study was to evaluate the effect of abrasion wear on surface roughness and microhardness of different commercially available resin composites simulating pH-challenges of the oral cavity. Methods: Three resin composites (RC) were used in this study: one conventional: Z250; and two bulk fill resin composites (BRC): Tetric N-Ceram (TNC) and Sonic Fill (SF). The RC was inserted in a prefabricated mold (15mm wide x 4mm thickness) in two layers, or in a single layer for BRC. Thirty samples were prepared and surface roughness (Ra) and Knoop microhardness (KHN) test were performed at three different time-points of evaluation: baseline (24h after sample preparation); partial (after pH cycling); and final (after simulated toothbrushing procedure). Two samples of each group were selected after different treatments and analyzed descriptively on a scanning electron microscopy (SEM). Data from Ra and KHN were analyzed by two-way repeated-measures ANOVA and Bonferroni's post-hoc test with a significance level set at 5%. Results: Ra increased for all groups (p<0.001), at the final time-point, Z250 and TNC groups present the highest values. Oppositely, KHN decreased for all groups (p<0.001), Z250 group showed the highest KHN values for all time-points (p<0.001). The SEM imagens showed a regular surface for samples cycled and irregular with inorganic particles exposed for samples toothbrushed. Conclusion: pH-cycling and simulated toothbrushing affected the superficial properties (roughness and Knoop microhardness), as observed at SEM imagens, with irregular surface with inorganic particles exposure

COVID-19 and isolation: Risks and implications in the scenario of new variants.

With the emergence of new variants of SARS-CoV-2, questions about transmissibility, vaccine efficacy, and impact on mortality are important to support decision-making in public health measures. Modifications related to transmissibility combined with the fact that much of the population has already been partially exposed to infection and/or vaccination, have stimulated recommendations to reduce the isolation period for COVID-19. However, these new guidelines have raised questions about their effectiveness in reducing contamination and minimizing impact in work environments. Therefore, a collaborative task force was developed to review the subject in a non-systematic manner, answering questions about SARS-CoV-2 variants, COVID-19 vaccines, isolation/quarantine periods, testing to end the isolation period, and the use of masks as mitigation procedures. Overall, COVID-19 vaccines are effective in preventing severe illness and death but are less effective in preventing infection in the case of the Omicron variant. Any strategy that is adopted to reduce the isolation period should take into consideration the epidemiological situation of the geographical region, individual clinical characteristics, and mask for source control. The use of tests for isolation withdrawal should be evaluated with caution, due to results depending on various conditions and may not be reliable.

Influence of inorganic composition and filler particle morphology on the mechanical properties of self-adhesive resin cements.

Objectives: This study aimed to evaluate the influence of inorganic composition and filler particle morphology on the mechanical properties of different self-adhesive resin cements (SARCs). Materials and Methods: Three SARCs including RelyX Unicem-2 (RUN), Maxcem Elite (MAX), and Calibra Universal (CAL) were tested. Rectangular bar-shaped specimens were prepared for flexural strength (FS) and flexural modulus (FM) and determined by a 3-point bending test. The Knoop microhardness (KHN) and top/bottom microhardness ratio (%KHN) were conducted on the top and bottom faces of disc-shaped samples. Sorption (Wsp) and solubility (Wsl) were evaluated after 24 hours of water immersion. Filler morphology was analyzed by scanning electron microscopy and X-ray energy dispersive spectroscopy (EDS). FS, FM, %KHN, Wsp, Wsl, and EDS results were submitted to 1-way analysis of variance and Tukey's post-hoc test, and KHN also to paired t-test (α = 0.05). Results: SARC-CAL presented the highest FS value, and SARC-RUN presented the highest FM. SARC-MAX and RUN showed the lowest Wsp and Wsl values. KHN values decreased from top to bottom and the SARCs did not differ statistically. Also, all resin cements presented carbon, aluminum, and silica in their composition. SARC-MAX and RUN showed irregular and splintered particles while CAL presented small and regular size particles. Conclusions: A higher mechanical strength can be achieved by a reduced spread in grit size and the filler morphology can influence the KHN, as well as photoinitiators in the composition. Wsp and Wsl can be correlated with ions diffusion of inorganic particles.

Evaluation of pretreatments on intra-radicular dentin bond strength of self-adhesive resin cements.

OBJECTIVES: To evaluate the influence of dentin pretreatments on the push-out bond strength (POBS) of self-adhesive resin cements (SARCs) to radicular dentin. MATERIALS AND METHODS: Two experimental pretreatments (2.5% titanium tetrafluoride (TiF4 ) and 26% polyacrylic acid (PA)) and two SARCs: Maxcem Elite (MAX) and Calibra Universal (CAL) were used. For each cement, a control group was applied as indicated by the manufacturer. Sixty bovine incisors were restored (n = 10) and subjected to POBS evaluation. Failure mode, adhesive interface and surface morphology were analyzed by a Scanning Electron Microscopy (SEM) and resin infiltration was performed by confocal laser scanning microscopy (CLSM). Data for POBS and CLSM were analyzed by three-way ANOVA and Bonferroni post-hoc (α = 0.05). RESULTS: For MAX, both experimental pretreatments resulted in increased POBS in the cervical third, and for CAL, only the PA resulted in higher POBS in the cervical third. The most failures occurred between the dentin and the resin cement, except when TiF4 was applied. For PA, analysis of surface morphology showed open dentinal tubules, while TiF4 presented particle agglomerates. SEM and CLSM images confirmed presence of resin tags for both pretreatments. CONCLUSION: Pretreating radicular dentin with PA and TiF4 solutions improves the bond strength of SARCs.

A Titanium Tetrafluoride Experimental Gel Combined with Highly Concentrated Hydrogen Peroxide as an Alternative Bleaching Agent: An In Vitro Study.

This in vitro study evaluated color change, mineral content, and morphology of enamel, pH and cytotoxicity of experimental bleaching agents containing 35% hydrogen peroxide (HP), titanium tetrafluoride (TiF4), Natrosol, and Chemygel. Sixty enamel/dentin blocks were randomly treated with (n = 10) HP; HP+Natrosol+Chemygel with different TiF4 concentrations: 0.05 g HPT0.5, 0.1 g HPT1, 0.2 g HPT2, 0.3 g HPT3, 0.4 g HPT4. Bleaching was performed in three sessions (3 × 15 min application). Color change (CIELab-ΔEab, CIEDE2000-ΔE00, ΔWID) and Knoop microhardness (KHN) were evaluated. Enamel morphology and composition were observed under scanning electron microscopy and energy-dispersive spectrometry (EDS), respectively. Cell viability of keratinocyte cells was evaluated using MTT assay. Data were analyzed by one-way ANOVA and LSD and Tukey tests, and two-way repeated measures ANOVA and Bonferroni (α = 5%). The pH and EDS were analyzed descriptively. Lightness-L* increased, and a* and b* parameters decreased, except for HPT3 and HPT4 (b*). HPT0.5, HPT1, and HPT2 exhibited ΔEab and ΔWID similar to HP. ΔE00 did not present statistical difference. HP, HPT0.5, and HPT1 promoted higher KHN. HPT0.5 exhibited no changes on enamel surface. Keratinocyte cells were viable when treated with T0.5, and weak viable for T1. Experimental agents exhibited acidic pH and Ti elements. HPT0.5 exhibited bleaching efficacy, maintained KHN without enamel alterations, and did not increase cytotoxicity.

DOES TITANIUM TETRAFLUORIDE PROMOTE A PROTECTIVE EFFECT ON ERODED TOOTH? A SYSTEMATIC REVIEW AND META-ANALYSIS.

OBJECTIVE: This systematic review and meta-analyses aimed to evaluate the potential protective effect of titanium tetrafluoride (TiF4) compound compared to sodium fluoride (NaF) on eroded enamel or dentin. METHODS: Two independent reviewers searched PubMed, Scopus, Web of Science, LILACS, Cochrane, EMBASE, and Open gray Literature up to June 2020. MeSH terms, supplementary concepts, synonyms, and free terms were applied based on PICOS strategy (P- population: eroded enamel or dentin; I- intervention: eroded teeth treated with solution or varnish of TiF4; C- comparison: eroded teeth treated with a solution or varnish of NaF; O- outcome: mineral loss measurement; S- study design: in vitro studies). Seven distinct parameters evaluated the risk of bias, and all studies were submitted to 4 meta-analyses (first and second meta-analyses related to enamel loss treated with fluoride solution or varnish, respectively; third and fourth meta-analyses related to dentin loss treated with fluoride solution or varnish, respectively). A sensitivity test was performed by the RevMan software, based on standard mean difference calculation (P < .05). RESULTS: A total of 10,260 studies were retrieved, from which 22 studies were included in systematic review through eligibility criteria, of which 1 study was classified as low risk of bias, 19 as medium, and 3 as high. Seventeen studies were included in 4 different meta-analyses, presenting considerable overall heterogeneity (I2 = 95; 92; 95; and 93%, respectively) with statistical significance for TiF4 on the first meta-analysis, and no statistical significance for second, third, and fourth meta-analyses. CONCLUSIONS: Titanium tetrafluoride compound delivered as solution provided significant effective protection for erosion lesions on the enamel surface compared to sodium fluoride. However, when TiF4 or NaF were applied on enamel or dentin surfaces as varnish, both provided the same effective protection, based on in vitro studies with considerable heterogeneity.

Does immediate dentin sealing influence postoperative sensitivity in teeth restored with indirect restorations? A systematic review and meta-analysis.

OBJECTIVE: This study comprehensively reviewed clinical trials that investigated the effect of immediate dentin sealing (IDS) technique on postoperative sensitivity (POS) and clinical performance of indirect restorations. MATERIALS AND METHODS: The systematic review was conducted according to the preferred reporting items for systematic reviews and meta-analyses statement, and was guided by the PICOS strategy. Clinical trials in which adult patients received at least one indirect restoration cemented with IDS approach and one restoration cemented following the delayed dentin sealing (DDS) were considered. RESULTS: Following title screening and full-text reading, four studies met the inclusion criteria and were included for qualitative synthesis, while two studies were selected for quantitative synthesis. According to Risk of bias-2 tool, two studies were classified as "some concerns" for the outcome POS. No statistically significant differences were found between teeth restored with indirect restorations using the IDS and DDS approach for POS (p > 0.05), neither at the baseline (very low certainty of evidence according to GRADE) nor after 2 years of follow-up (low certainty of evidence according to GRADE). CONCLUSION: There is low-certainty evidence that IDS does not reduce POS in teeth restored with indirect restorations. CLINICAL SIGNIFICANCE: There is no clinical evidence to favor IDS over DDS when restoring teeth with indirect restorations.

The influence of the renewal or the single application of the peroxide gel on the efficacy and tooth sensitivity outcomes of in-office bleaching-A systematic review and meta-analysis.

OBJECTIVE: To answer the question: "Does the peroxide gel application regimen (single application vs. renewal) influence the efficacy and the tooth sensitivity outcomes of in-office tooth bleaching?" METHODS: The search was done in Pubmed, Cochrane, LILACS, Scopus, Web of Science, and EMBASE in February 2021 (updated in July 2021). Randomized clinical trials (RCT) comparing the single application vs. the renewal protocols of HP were included. The meta-analyses were performed for the objective (ΔEab ), subjective (ΔSGU) color changes, and absolute risk of tooth sensitivity (TS). Heterogeneity was evaluated using Q test (I2 ). Cochrane Collaboration tool assessed the risk of bias (RoB). The GRADE evaluated the certainty of evidence. RESULTS: Five RCT studies remained. Two studies showed high RoB, and three presented some concerns. No significant differences were observed between the protocols in terms of the ΔEab , ΔSGU, and TS. ΔEab exhibited substantial heterogeneity (I2  = 87%), while ΔSGU (I2  = 60%) and the TS (I2  = 62%) presented a moderate one. The certainty of evidence was considered low or very low, depending on the variable response and the evaluation time. CONCLUSION: The application regimen (single vs. renewal of HP) did not impact color change or the absolute risk of TS. CLINICAL SIGNIFICANCE: The renewal of bleaching gel during the in-office appointment may not be necessary. However, there is at least a low certainty of evidence. Because of this, further randomized clinical trials with appropriate methodology on this topic are encouraged.

Do Bulk-Fill Resin Composites Present More Susceptibility to Marginal Degradation in Different Clinical Scenarios? A Systematic Review and Meta-Analysis

Abstract Objective: To compare the marginal degradation (susceptibility to marginal adaptation and marginal discoloration) of composite restorations placed in class II and V cavities using conventional and bulk-fill resin composites. Material and Methods: This study was approved by PROSPERO database (#42020201596). PubMed, Scopus, Embase, Web of Science, Lilacs, Cochrane, Open Grey, Clinical Trials, and Rebec databases were searched by three independent investigators using MeSH terms, supplementary concepts, synonyms, and free keywords, based on the PICOS strategy (P, population: restoration in permanent teeth; I, intervention: bulk-fill resin composite; C, comparison: conventional resin composite; O, outcome: marginal discoloration and adaptation; and S, study design: randomized and non-randomized clinical trials). The risk of bias was evaluated according to the Cochrane Collaboration's tool, the meta-analyses by RevMan software, the certainty of evidence by the Grading of Recommendations Assessment, Development, and Evaluation, and the leave-one-out sensitivity test. The prevalence of successful events and the total number of restorations were used to calculate the risk difference at a confidence interval of 95%, according to a fixed-effect model. The heterogeneity was evaluated using the I2 index. Results: 16 from 10,780 studies were selected and included for qualitative and quantitative analysis. Two studies were considered as high risk of bias, one showing some concerns, and 13 as low risk of bias. Four meta-analyses evaluated the marginal adaptation and marginal discoloration in class II and V cavities, with a nonsignificant heterogeneity (I2 = 0%, p>0.05). The certainty of evidence was considered high, except for two subgroups of each outcome. Conclusion: There is evidence that composite restorations using conventional and bulk-fill resin composites present similar clinical performance related to marginal degradation (AU).

COVID-19 and isolation: Risks and implications in the scenario of new variants

Abstract With the emergence of new variants of SARS-CoV-2, questions about transmissibility, vaccine efficacy, and impact on mortality are important to support decision-making in public health measures. Modifications related to transmissibility combined with the fact that much of the population has already been partially exposed to infection and/or vaccination, have stimulated recommendations to reduce the isolation period for COVID-19. However, these new guidelines have raised questions about their effectiveness in reducing contamination and minimizing impact in work environments. Therefore, a collaborative task force was developed to review the subject in a non-systematic manner, answering questions about SARS-CoV-2 variants, COVID-19 vaccines, isolation/quarantine periods, testing to end the isolation period, and the use of masks as mitigation procedures. Overall, COVID-19 vaccines are effective in preventing severe illness and death but are less effective in preventing infection in the case of the Omicron variant. Any strategy that is adopted to reduce the isolation period should take into consideration the epidemiological situation of the geographical region, individual clinical characteristics, and mask for source control. The use of tests for isolation withdrawal should be evaluated with caution, due to results depending on various conditions and may not be reliable.

Gut microbiota: A potential therapeutic target for management of diabetic retinopathy?

Diabetic Retinopathy (DR) is one of the main complications of Diabetes Mellitus (DM), drastically impacting individuals of working age over the years, being one of the main causes of blindness in the world. The existing therapies for its treatment consist of measures that aim only to alleviate the existing clinical signs, associated with the microvasculature. These treatments are limited only to the advanced stages and not to the preclinical ones. In response to a treatment with little resolution and limited for many patients with DM, investigations of alternative therapies that make possible the improvement of the glycemic parameters and the quality of life of subjects with DR, become extremely necessary. Recent evidence has shown that deregulation of the microbiota (dysbiosis) can lead to low-grade, local and systemic inflammation, directly impacting the development of DM and its microvascular complications, including DR, in an axis called the intestine-retina. In this regard, the present review seeks to comprehensively describe the biochemical pathways involved in DR as well as the association of the modulation of these mechanisms by the intestinal microbiota, since direct changes in the microbiota can have a drastic impact on various physiological processes. Finally, emphasize the strong potential for modulation of the gut-retina axis, as therapeutic and prophylactic target for the treatment of DR.

Effect of wetting agent coverage on the surface properties of resin composite submitted to brushing and staining cycles.

BACKGROUND: Wetting agents facilitate the composites handling, acting as a lubricant and decreasing their stickness to spatula. The effects of these materials on the properties of composites are not completely clear. This study aimed to evaluate Gloss, Color, Roughness and Microhardness of a composite (Filtek Z250 XT, 3M Oral Care) covered by a wetting agent (Modeling Resin, Bisco), submitted to brushing and staining cycles with red wine. MATERIAL AND METHODS: Cylinder-shaped samples (8 mm ø x 2 mm height) were divided into 4 groups, according to application of wetting agent and brushing cycles (n = 20). The composite was placed in the orifice of a polytetrafluoroethylene mold, received wetting agent coverage, and was light-cured. Gloss, Color, Roughness and Microhardness were evaluated in two times: after samples confection and after brushing + staining cycles. Data were submitted to one-way ANOVA and Tukey's test (ΔL, Δa, Δb and ΔE) and two-way repeated measures ANOVA and Bonferronis's test (gloss, roughness and microhardness). RESULTS: In general, the composite showed higher gloss values when added by the wetting agent. No statistical differences were observed regarding colors' groups. Roughness increased after brushing cycles, regardless of wetting agent application. The only group which presented decreased Microhardness after cycles was the group without wetting agent, only submitted to staining with red wine. CONCLUSIONS: The application of wetting agent on the composite did not interfere negatively with its properties of Gloss, Color, Roughness and Microhardness. Key words:Resin composite, wetting agent, surface properties, gloss, color, esthetic dentistry.

Microtensile Bond Strength, Bonding Interface Morphology, Adhesive Resin Infiltration, and Marginal Adaptation of Bulk-fill Composites Placed Using Different Adhesives.

PURPOSE: This study evaluated dentin bond strength, failure mode, interface morphology, adhesive infiltration into dentin, and marginal adaptation of bulk-fill composites used with different adhesives. MATERIALS AND METHODS: Third molars received occlusal class I cavities (4 mm x 4 mm x 4 mm) that were bulk-filled with Admira Fusion x-tra (Voco) or SonicFill 2 (Kerr) using four adhesives (Scotchbond Multipurpose, 3M Oral Care; Clearfil SE Bond, Kuraray Noritake; OptiBond All-In-One, Kerr; Futurabond U, Voco). Scotchbond was used with acid-etching, while the remaining adhesives were applied in self-etch mode. Sixty-four teeth were selected for the microtensile bond strength test (n = 8). Failure modes were analyzed with scanning electron microscopy (SEM). Interface morphology and adhesive infiltration (n = 3) were investigated using confocal laser scanning microscopy (CLSM). Marginal adaptation (n = 3) was also evaluated using SEM. Bond strength, failure mode, and adhesive infiltration data were analyzed for distribution and homocedasticity, followed by appropriate statistical analyses (α = 0.05). RESULTS: Regarding bond strength, no differences were found among adhesives for SonicFill; Clearfil showed a significantly lower mean value than did Scotchbond (p ≤ 0.05) for Admira; the two composites did not differ. Adhesive and mixed failures were observed for all groups. Scotchbond led to thicker hybrid layers with deeper adhesive infiltration as opposed to Futurabond. The groups Admira+Futurabond, SonicFill+Clearfil, and SonicFill+Futurabond presented the highest marginal discontinuity. CONCLUSION: The tested bulk-fill composites did not affect dentin bonding. Scotchbond and Clearfil seem to be reliable for bonding SonicFill 2 to dentin. The performance of Futurabond was questionable, given its poor-quality interface and higher percentages of marginal gaps.

Assessment of a novel bleaching agent formula containing 35% hydrogen peroxide and titanium tetrafluoride: an in vitro study.

This study developed experimental gels containing titanium tetrafluoride (TiF4) combined with commercial 35% hydrogen peroxide (HP), and evaluated bleaching efficacy and pH of the gels, and mineral content and morphology of enamel submitted to these treatments. In phase-1, different stock gels mixed with TiF4 were combined with HP. In phase-2, the selected gels were tested on enamel/dentin specimens (n=8): HP; HP and Natrosol+TiF4 (HPnT); HP and Natrosol+Chemygel+TiF4 (HPncT); HP and Aristoflex+TiF4 (HPaT). Bleaching was performed in four sessions (3x15min-application/session). Color (CIEL*a*b*) and whiteness index (WID) were measured after each session, whereas whiteness index differences (ΔWID), color alteration (CIELab-ΔE, CIEDE2000-ΔE00), enamel morphology and pH, at end of bleaching therapy. The change in Knoop microhardness (ΔKHN) was compared before and after bleaching. Data were analyzed by two-way repeated measures ANOVA and Bonferroni (CIEL*, a*, b*), one-way ANOVA and Tukey (ΔWID, ΔE, ΔE00), and LSD (ΔKHN) tests (α=5%). SEM and pH measurements were submitted to descriptive analysis. No differences were observed in lightness (L*) or WID among the groups (p > 0.05), but HP exhibited lower b* values (p<0.05), higher ΔWID than HPnT, and the highest ΔE among the groups (p < 0.05). No differences in ΔE00 were observed between HP and HPncT (p > 0.05), and HPncT showed higher ΔKHN than HP (p < 0.05). HP presented pH values closer to neutral (6.9), whereas experimental agents showed acidic pH values (2.3-3.9). No morphological changes were observed in HP or HPncT groups. HPncT was able to bleach the enamel and maintain enamel microhardness and surface integrity, even at low pH.

Efficacy of whitening toothpaste containing blue covarine: A double-blind controlled randomized clinical trial.

OBJECTIVE: This randomized clinical trial evaluated the efficacy and safety of a blue-covarine whitening toothpaste on tooth bleaching. SUBJECTS AND METHODS: Seventy-five subjects with shade mean C1 or darker were randomized into three groups (n = 25): CT-conventional toothpaste, WT-whitening toothpaste, and CP10-10% carbamide peroxide. Subjects from CT and WT brushed their teeth twice/day for 2 weeks. CP10 used bleaching gel for 4 hours/night for 2 weeks. Tooth shade and CIELab parameters were measured at baseline, after the first application, 2- and 4-week. ΔE*ab and ΔE00 were calculated. Subjects' perception about tooth color appearance, tooth sensitivity (TS), and gingival irritation (GI) were also assessed. RESULTS: At all evaluation periods, it was not observed differences between WT and CT considering tooth shade (P > 0.7) or CIELab parameters (P > 0.3). At 2- and 4-week, ΔE*ab and ΔE00 were higher for CP10 than WT or CT (P = 0.001). WT and CT reported major dissatisfaction with tooth color appearance than CP10 (P = 0.001). At 1- and 2-week, WT experienced GI and TS similar to CT, both lower than CP10 (P < 0.01). CONCLUSION: There were no significant differences in the whitening efficacy between whitening and conventional toothpastes. Neither of the dentifrices was as effective as at-home bleaching. CLINICAL SIGNIFICANCE: The silica-based toothpaste containing blue covarine evaluated in this study did not give significant tooth whitening benefits over 2 weeks of use.

Characterization of low-cost Brazilian resin composites submitted to tooth brushing.

This in vitro study aimed to evaluate surface microhardness, roughness, color, gloss and topography of low-cost Brazilian resin composites, compared with an international one. All 120 samples (8mm ø x 2mm height) were prepared and divided into 5 groups: Ultrafill (Biodinâmica), Llis (FGM), Fill Magic (Coltene), Applic (Makira), and Filtek Z250XT (3M Oral Care). Surface microhardness (KHN) (n=10) was analyzed at two time periods: before and after simulated tooth brushing (STB). Other standardized samples of each group (n=10) were analyzed for surface roughness (Ra), color (ΔL, Δa, Δb, ΔE, ΔE00) and gloss unit (GU) at the same two periods. The topography of non-brushed and brushed samples of each group (n=4) was evaluated by scanning electron microscopy. Data were analyzed statistically by two-way repeated measures ANOVA with Bonferroni post-hoc test (KHN, Ra, GU), and one-way ANOVA with Tukey post-hoc test (ΔL, Δa, Δb, ΔE, ΔE00) (α=0.05). Topographic images were submitted to descriptive analysis. The low-cost Brazilian resin composites investigated were compared with the international one and revealed: lower KHN, regardless of before or after STB; statistically similar Ra before STB, except Ultrafill, which presented higher values; lower Ra after STB, except Ultrafill, which presented statistically similar values; statistically similar color change in ΔL, Δa, Δb parameters; statistically similar color change in ΔE, ΔE00 parameters, except Fill Magic, which presented lower values; lower gloss before STB; lower gloss after STB, except Ultrafill, which presented statistically similar values. In a situation of scarce resources, low-cost Brazilian composites might be an acceptable cost-effective restorative alternative.

Flowable and Regular Bulk-Fill Composites: A Comprehensive Report on Restorative Treatment.

This article reports a comprehensive restorative treatment using bulk-fill composites and discusses their properties and clinical performance. A 20-year-old man sought dental treatment due to the dark shade of his smile and multiple old amalgam fillings. Based on clinical and radiographic findings, and the patient's demand for tooth-colored fillings, treatment comprised enamel microabrasion and in-office dental bleaching, followed by the replacement of amalgam fillings by bulk-fill composites. Bulk-fill composites exhibit modifications in the filler size and shape or in the chemistry of monomers that allow them to be applied in thicker layers (4 to 5 mm), creating opportunities for simpler, faster, and more-efficient clinical procedures, as seen in the present report.

New details of assembling bioactive films from dispersions of amphiphilic molecules on titania surfaces.

Tailoring the surface properties of materials for biomedical applications is important to avoid clinical complications. Forming thin layers of amphiphilic molecules with apolar regions that facilitate attractive intermolecular interactions, can be a suitable and versatile approach to achieve hydrophobic surface modification and provide functional antibacterial properties. Aiming to correlate layer structure and properties starting from film formation, octadecylphosphonic acid (ODPA) and dimethyloctadecyl (3-trimethoxysilylpropyl) ammonium chloride (DMOAP) layers were adsorbed onto smooth titania surfaces. Then the films were studied by atomic force microscopy (AFM) and X-ray Photoelectron Spectroscopy (XPS), and their interactions with aqueous environments were characterized by contact angle and zeta potential measurements. In addition, antibacterial assays were performed using E. coli and S. mutants to reveal the antibacterial properties effected by the surface modification. Immediately after sputter deposition, titania was hydrophilic; however, after air storage and adsorption of DMOAP or ODPA, an increase in the water contact angle was observed. XPS investigations after layer formation and after antibacterial tests revealed that the attachment of layers assembled from ODPA on titania substrates is considerably stronger and more stable than that observed for DMOAP films. Heat treatment strongly affects DMOAP layers. Furthermore, DMOAP layers are not stable under biological conditions.