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This paper presents an exploratory study on the knowledge and importance of integrating Lean Education in curricula from the Academy perspective. The study was based on the analysis of participants' outcomes of workshops settled in international conferences. These workshops were used to promote Lean Education as a fundamental content and competency to be taught to the new professionals, independently of their future activity. Having in their DNA Lean content and competency, professionals will be thinkers adopting whole system-thinking, a sustainable conscious and ethical behaviour prepared to face Fourth industrial revolution demands. The authors believe that Lean Education provides such competencies to the new professionals and have been settling and operationalized such workshops in different contexts, involving more than 100 participants (mainly, academics) with teaching responsibilities in training the future workforce. Workshops outcomes were obtained from participants' active discussions and through a satisfaction assessment questionnaire filled by all participants at the end of the workshop. Results show that Lean Education is valuable by academics (more than 50% of the participants gave a high score to the practicality, value, and timeliness of the workshop contents). Nevertheless, a small percentage (12%) knows what Lean Education is or teaches Lean in the classes (10%). [ABSTRACT FROM AUTHOR]

Objectives: to assess the cytotoxicity of the following functional monomers used in dental adhesives: 10-Methacryloyloxydecyl dihydrogen phosphate (10-MDP) and glycerol phosphate dimethacrylate (GPDM), and their effect on cytokine release from human dental pulp stem cells (hDPSCs)., Methods: The hDPSCs cells were isolated from the dental pulp of extracted human third molars. The functional monomers, 10-MDP and GPDM, were diluted in dimethyl sulfoxide (DMSO) at concentrations ranging from 1 to 4 mM. Cells not exposed to the compounds served as controls. The hDPSCs were seeded into 96-well plates and incubated for 48 h. Subsequently, the cells were exposed to 10-MDP and GPDM for 24 h. Then, the culture medium was removed, the mitochondrial metabolism was evaluated using the MTT assay, while cell death analyzed by flow cytometry. Cytokine release (IL-1β, IL-6, IL-8, IL-10, TNF-α) was analyzed by the MAGPIX. The data were analyzed using one-way ANOVA and Tukey's test., Results: 10-MDP demonstrated significant toxicity to hDPSCs, reaching the IC50 at 3 mM. However, its impact on cytokine release was minimal, resulting only in IL-6 and IL-8 levels. GPDM exhibited lower toxicity, even at 4 mM, but induced an increase in IL-1β release and a reduction in IL-6, IL-8, and IL-10 levels, with no effect on TNF-α. Despite the MTT assay results indicating cytotoxicity, the cell death was low for both functional monomers., Significance: 10-MDP exhibited significant toxicity to hDPSCs, unlike GPDM, however, both monomers resulted in minimal cell death. 10-MDP had a minor impact on cytokine release, whereas GPDM demonstrated a potential to trigger an inflammatory reaction, particularly in the short term., Competing Interests: Declaration of Competing Interest The authors declare no potential conflicts of interest concerning the authorship or publication of this work. This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Objective: To investigate the effect of reducing exposure time to at-home bleaching gel on color change and tooth sensitivity., Materials and Methods: The search was carried out using PubMed, Scopus, Web of Science, EMBASE, LILACS, Cochrane. Randomized clinical trials (RCTs) were included involving adult patients who have never undergone bleaching treatment before (P), subjected to bleaching with a reduced exposure time to the at-home bleaching agent (I) compared to those who used it for the time indicated by the manufacturer (C), to evaluate the effects on color change and tooth sensitivity (O). The Cochrane guidelines for the Risk of Bias Assessment Tool (RoB 2.0) and GRADE were used to assess risk of bias and quality of evidence, respectively., Results: Using at-home bleaching gel for the period recommended by the manufacturer resulted in significantly higher ΔE ab and ΔWI D values and better subjective color change (ΔSGU-Classical), regardless of the evaluation time. Regarding the post-bleaching evaluation, no significant differences were found for ΔE 00 immediately after bleaching or ΔSGU (Bleached) at any time. Reducing the time of use significantly decreased tooth sensitivity events., Conclusions: Reducing exposure time to at-home bleaching gel reduces tooth sensitivity events; however, most of the parameters that assess color change indicate using at-home bleaching gel for the time recommended by the manufacturer., Clinical Significance: Reducing exposure time to at-home bleaching gel should be applied with caution in clinical practice. Although the evidence suggests a reduction in tooth sensitivity events, bleaching effectiveness was significantly higher after using the bleaching gel for the time indicated by the manufacturer., Competing Interests: Declarations. Ethics approval and consent to participate: Not Applicable. Conflict of interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objectives: To evaluate the effects of dentifrices containing sodium fluoride (NaF) combined with NovaMin (Sensodyne Repair & Protect-SRP), NaF combined with stannous fluoride (SnF 2 , Oral-B Pro-Gengiva-OBP), and amine fluoride (AmF, Colgate Elmex-ELM) on enamel subjected to simulated erosive cycling., Materials and Methods: Bovine enamel-dentin discs (n = 10/group) were subjected to erosive cycling with orange juice (pH = 3.29, 5 min, 3x/day), artificial saliva (SA-2 h, 3x/day and overnight) and treated with dentifrice (2 min, 2x/day) or without treatment (CONT). Surface microhardness (SMH) was evaluated at baseline (T 0 ), on the first (T 1 ) and fifth (T 5 ) days. SMH loss (%SHL) was calculated. Surface roughness (Ra, μm) was determined at T 0 and T 5 . Morphology and mineral content were evaluated under scanning electron microscopy and energy-dispersive x-ray spectroscopy. Data were analyzed using ANOVA/Tukey or Bonferroni (α = 5%)., Results: No differences in %SHL were detected among groups at T 1 . At T 5 , OBP promoted %SHL, Ra, and ΔRa significantly lower than all the other groups (p < 0.05). All groups exhibited morphological changes in topography and similar Ca/P means before and after treatments., Conclusions: Dentifrice containing SnF 2 minimized the negative effects on the SMH and Ra caused by exposure to orange juice after 5 days of simulated cycling., Clinical Relevance: Patients who are more exposed to risk factors for dental erosion could benefit from the use of dentifrice containing SnF 2 ., (© 2024 Wiley Periodicals LLC.)

Aim: This study evaluated the efficacy and cytotoxicity of 35% hydrogen peroxide (HP) gel incorporated with 10% (w/w) biosilicate (BioS) on sound enamel and early-stage enamel erosion lesions., Methods: Discs of enamel/dentin were selected, subjected to erosive cycles (0.3% citric acid, pH 2.6), and treated with (n = 8): HP (35% HP, positive control); HP&#95;BioS [carboxymethyl cellulose (CMC) + HP + BioS]; BioS (CMC + BioS); CMC (negative control). The discs were adapted to artificial pulp chambers with the enamel exposed for bleaching, and the dentin facing toward the culture medium (Dulbecco's modified Eagle's medium [DMEM]). Bleaching was performed in three 30-min sessions at 7-day intervals. After bleaching, the diffusion product (DMEM extract + diffused HP) was pipetted onto MDPC-23 odontoblastic cell line and inoculated. Color parameters (ΔL, Δa, Δb), color change (ΔE 00 ), and changes in whiteness index (ΔWI D ) were determined before (T 0 ) and after the last bleaching session (T 3 ). Cell viability (MTT, %), H 2 O 2 diffusion (μg/mL), oxidative cell stress (OxS), and cell fluorescence (live/dead assay, in confocal microscopy) were assessed (ANOVA/Tukey; α = 0.05)., Results: No difference in ΔL, Δa, Δb, ΔE 00 , and ΔWI D were found between HP and HP&#95;BioS (p > 0.05). The incorporation of BioS decreased the HP diffusion into the substrates and mitigated oxidative stress in early-stage eroded enamel (p < 0.05). HP&#95;BioS presented significantly higher cell viability compared with HP under erosion conditions. Live/dead assay indicated that BioS&#95;HP maintained viability with larger clusters of viable cells., Conclusion: Incorporating BioS into HP maintained bleaching effectiveness, favored cell viability, reduced the oxidative stress, and the cytotoxicity in teeth with early-stage erosion., Clinical Significance: BioS formulation showed promising results for reducing cytotoxicity in patients seeking tooth bleaching and presenting undetectable early-stage erosion., (© 2024 Wiley Periodicals LLC.)

Objective: To evaluate the efficacy and cytotoxicity of experimental 6% and 35% hydrogen peroxide gels (HP6 or HP35) incorporated with titanium dioxide nanoparticles (NP) co-doped with nitrogen and fluorine and irradiated with a violet LED light (LT)., Methods: Bovine enamel-dentin disks adapted to artificial pulp chambers were randomly assigned to bleaching (n = 8/group): NC (negative control), NP, HP6, HP6 + LT, HP6 + NP, HP6 + NP + LT, HP35, HP35 + LT, HP35 + NP, HP35 + NP + LT, and commercial HP35 (COM). Color (ΔE 00 ) and whiteness index (ΔWI D ) changes were measured before and 14 days after bleaching. The extracts (culture medium + diffused gel components) collected after the first session were applied to odontoblast-like MDPC-23 cells, which were assessed concerning their viability, oxidative stress, and morphology. The amount of HP diffused through the disks was determined. Data were analyzed by generalized linear models or Kruskal Wallis Tests (α = 5%).  RESULTS: HP6 + NP + LT exhibited ΔE 00 and ΔWI D higher than HP6 (p < 0.05) and similar to all HP35 groups. HP6 + NP + LT showed the lowest HP diffusion, and the highest cell viability (%) among bleached groups, preserving cell morphology and number of living cells similar to NC and NP. HP6 + LT, HP6 + NP, and HP6 + NP + LT exhibited the lowest cell oxidative stress among bleached groups (p < 0.05). HP35, HP35 + LT, and HP35 (COM) displayed the lowest cell viability., Conclusion: HP6 achieved significantly higher color and whiteness index changes when incorporated with nanoparticles and light-irradiated and caused lower cytotoxicity than HP35 gels. The nanoparticles significantly increased cell viability and reduced the hydrogen peroxide diffusion and oxidative stress, regardless of HP concentration., Clinical Significance: Incorporation of co-doped titanium dioxide nanoparticles combined with violet irradiation within the HP6 gel could promote a higher perceivable and acceptable efficacy than HP6 alone, potentially reaching the optimal esthetic outcomes rendered by HP35. This approach also holds the promise of reducing cytotoxic damages and, consequently, tooth sensitivity., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

To evaluate the physical properties of enamel submitted to hydrogen peroxide (HP) incorporated with titanium dioxide nanoparticles (NP) co-doped with nitrogen and fluorine and irradiated with violet LED light (LT). Enamel-dentin disks were randomly allocated (T 0 ) into groups, according to HP (HP6, HP15, or HP35) and NP (no NP, 5NP, or 10NP) concentrations, and irradiated or not with LT. A negative control (NC) group was set. After three bleaching sessions (T 1 , T 2 , and T 3 ), specimens were stored in saliva for 14 days (T 4 ). Enamel surface microhardness number (KHN), surface roughness (Ra), cross-sectional microhardness (ΔS), energy-dispersive spectroscopy (EDS), scanning electron (SEM), and polarized light (PLM) microscopies were performed. Surface KHN was significantly influenced by NP over time, independently of LT irradiation. At T 3 and T 4 , gels with 5NP and 10NP exhibited no KHN differences compared to NC and baseline values, which were not observed under the absence of NP. NP incorporation did not statistically interfere with the ΔS and Ra. PLM images exhibited surface/subsurface darkening areas suggestive of demineralizing regions. SEM demonstrated some intraprismatic affection in the groups without NP. EDS reported a higher enamel calcium to phosphorus ratio following 10NP gels applications. Gels with NP maintained the enamel surface microhardness levels and seemed to control surface morphology, upholding the mineral content. None of the proposed experimental protocols have negatively influenced the enamel surface roughness and the cross-sectional microhardness., (© 2024. The Author(s), under exclusive licence to The Society of The Nippon Dental University.)

Objective: This randomized controlled clinical trial evaluated the whitening efficacy, tooth sensitivity (TS), and volunteers' satisfaction following the use of activated charcoal powder and toothpaste., Methods: Fifty-six volunteers were randomly allocated into 4 groups (n = 14) according to a 14-day toothbrushing or whitening treatment with activated charcoal powder (ACPW), activated charcoal toothpaste (ACT), regular fluoridated toothpaste (RT), and 10 % carbamide peroxide (CP). Objective (ΔE 00 ) and subjective (ΔSGU) color and whiteness index (ΔWI D ) changes were calculated. Patients self-reported the risk and intensity of TS using a visual analogue scale and the volunteer's satisfaction was determined by a questionnaire. Color assessments were analyzed by Kruskal-Wallis followed by Dwas-Steel-Crithlow-Fligner, and absolute TS risk and volunteer's satisfaction by Fisher exact test (p < 0.05)., Results: ACPW and ACT promoted similar effects in ΔE 00 , ΔSGU, and ΔWI D to that observed for RT. No significant difference was found in terms of TS risk intensity. TS risk became high after 7 and 14 days, with higher TS prevalence in CP. Volunteers reported that ACPW exhibited the lowest ease-of-use, comfort, and whitening satisfaction among groups (p < 0.05)., Conclusion: Activated charcoal-based products presented a minor and unsatisfactory whitening effect while CP resulted in optimal tooth whitening and the highest level of satisfaction among volunteers. Risk was higher from 7 days onwards and was more pronounced in the CP., Clinical Relevance: Based on the whitening effect and patient satisfaction, this controlled-randomized clinical evidence supports that the use of activated charcoal-based products should be discouraged., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

This study aimed to evaluate surface roughness (Sa), roughness profile (Rv), and enamel wear after brushing with different whitening toothpastes and charcoal powders. Sixty (n = 10) bovine enamel blocks (6 × 6 × 3 mm) were randomly distributed into six groups according to toothpaste type: regular toothpaste (CONT), toothpaste containing 2% hydrogen peroxide (HP), toothpaste containing titanium dioxide (TiO2), toothpaste containing charcoal (COAL), toothpaste containing charcoal and TiO2 (COAL+TiO2), and activated charcoal powder (COAL&#95;PWD). Each block was subjected to 30,000 reciprocal cycles at a 1:3 proportion slurry. After brushing, the blocks were analyzed using an optical profilometer to determine Sa, Rv, and enamel wear. In addition, representative 3D images of each group and wear profiles were obtained. Sa was analyzed using generalized linear models followed by Bonferroni correction, whereas Rv was analyzed using one-way analysis of variance. After brushing, COAL and COAL+TiO2 showed higher Sa values than COAL&#95;PWD. However, no significant difference was observed in Sa between whitening toothpaste and COAL&#95;PWD, and CONT (p > 0.05). In addition, no differences were observed among the groups in Rv (p > 0.05). Conversely, enamel wear was higher for TiO2, COAL, COAL+TiO2, and COAL&#95;PWD than for CONT. CONT showed the least enamel wear, whereas HP showed intermediate values. Representative 3D images and line profiles showed lower step-height and lower mean surface losses for the CONT and HP groups than for the other groups. Whitening toothpastes and COAL&#95;PWD did not increase Sa or Rv compared with CONT, while CONT demonstrated lower enamel wear.

Objectives: The objective of the study is to evaluate the bleaching potential of 6% hydrogen peroxide (6% HP) gels containing NF&#95;TiO 2 or Nb 2 O 5 irradiated with a violet LED light and the effects on enamel mineral content and surface morphology., Methods: Particles were synthesized, and experimental gels were chemically analyzed by preliminary and accelerated stability tests, pH, and HP decomposition rate. Bovine enamel blocks were treated with 6% HP gels containing (n = 10): 5% NF&#95;TiO 2 , 5% Nb 2 O 5 , 2.5% NF&#95;TiO 2  + 2.5% Nb 2 O 5 or without particles (6% HP), irradiated or not with LED, and the control was treated with 35% HP. Color (∆E 00 ) and whitening index (∆WID) variations, surface microhardness (SH), average roughness (∆Ra), Ca-P concentration (EDS), and enamel morphology (SEM) were assessed. Bleaching was performed in 3 sessions of 30 min and 7-day intervals. Data were submitted to two- (pH, decomposition rate, ∆E 00 , and ∆WID) or three-way ANOVA and Bonferroni (SH), Kruskal-Wallis (∆Ra), and Dunnet tests (α = 0.05)., Results: No changes in the gel's color, odor, or translucency were observed. The pH (6 to 6.5) remained stable over time, and light irradiation boosted the HP decomposition rate. NF&#95;TiO 2 and Nb 2 O 5 -containing gels displayed higher ∆E 00 and ΔWID when light-irradiated (p < 0.05). Nb 2 O 5 and Nb 2 O 5  + NF&#95;TiO 2 decreased enamel SH (p < 0.05), but no SH changes were found among groups (p > 0.05). No differences among groups were noted in ∆Ra, Ca-P content, and enamel morphology after treatments (p > 0.05)., Conclusion: Experimental light-irradiated 6% HP gels containing NF&#95;TiO 2 or Nb 2 O 5 were chemically stable and exhibited bleaching potential comparable with 35% HP., Clinical Relevance: Low-concentrated HP gels containing NF&#95;TiO 2 or Nb 2 O 5 and light-irradiated stand as a possible alternative to in-office bleaching., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

This study developed an experimental flowable composite incorporated with niobium pentoxide (Nb 2 O 5 ) combined or not with titanium dioxide co-doped with fluorine and nitrogen (NF&#95;TiO 2 ) and evaluated the mechanical and antibacterial properties. The experimental flowable composite (TEGDMA + BisGMA 1:1 + 60%wt - inorganic filler - borosilicate 0.7 μm) was formulated according to the type and concentration of Nb 2 O 5 and NF&#95;TiO 2 (0.5, 1, 1.5 and 2 wt%) or NF&#95;TiO 2  + Nb 2 O 5 (0.25, 0.5, 0.75 and 1 wt% - 1:1). The control groups were formed by the experimental composite without the incorporation of Nb 2 O 5 and/or NF&#95;TiO 2 (GC-E) and by a commercial flowable composite (GC). The characterization of the surface of the composite and its particles was carried out using scanning electron microscopy (SEM) and energy dispersive x-rays (EDX). Specimens were manufactured and subjected to mechanical tests of flexural strength (FS) (n = 12), flexural modulus (FM) (n = 12), roughness (Ra) (n = 10), microhardness (n = 10), and contact angle (n = 10); and, to evaluate the antibacterial activity, they were submitted to tests of biofilm formation against S. mutans (CFU/mL) (n = 5), biofilm biomass by dry weight (n = 5) and confocal laser microscopy (%LIVE/DEAD) (n = 5). Data were submitted to one-way ANOVA and Tukey's post-hoc and, those that were not homoscedastic, but with normality, were submitted to Welch's ANOVA and Games-Howell's post-hoc. Dunnet's test was used to compare the controls with the other experimental groups (α = 5). The Nb 2 O 5 particles had an average size of 32.4 μm and the nanoparticles (NPs) of NF&#95;TiO 2 , 10 nm. EDX analysis identified isolated peaks of N, F, Ti, and Nb confirming the presence of these particles in the resin matrix. The 1.5% NF&#95;TiO 2 group had a higher FS and FM than the controls (p < 0.05). GC showed higher microhardness between groups (p < 0.05). There was no difference between the experimental groups regarding contact angle and roughness (p > 0.05), except for GC, which had the highest Ra values and the lowest contact angle between groups (p < 0.05). Composites containing 0.5%, 1%, 1.5%, and 2% Nb 2 O 5 , 1%, 1.5%, and 2% NF&#95;TiO 2 and 2% Nb 2 O 5  + NF&#95;TiO 2 showed lower biofilm formation (p < 0.05), lower total biofilm biomass (p < 0.05), and a higher percentage of dead cells (44%, 52%, 52%, 79%, 42% 43%, 62%, 65%, respectively) than GC and GC-E (5% and 1%, respectively). It is concluded that the incorporation of 1.5% NF&#95;TiO 2 promoted a greater FS and FM among the experimental composites and that the addition of Nb 2 O 5 particles (0.5%, 1%, 1.5%, and 2%), NF&#95;TiO 2 (1%, 1.5% and 2%) and the combination Nb 2 O 5  + NF&#95;TiO 2 (2%) showed significant antibacterial effects., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Purpose: This study evaluated enamel with early-stage erosion/abrasion following bleaching with 20% and 45% carbamide peroxide (CP) gels containing fluoride (F) and irradiated with violet LED (LED)., Methods: Enamel blocks were immersed in 1% citric acid (5 min) and artificial saliva (120 min) three times to produce early-stage enamel erosion. Simulated toothbrushing was performed only after the first saliva immersion, to provoke enamel abrasion. The erosive/abraded enamel samples were submitted to (n=10): LED/CP20, CP20, LED/CP20&#95;F, CP20&#95;F, LED/CP45, CP45, LED/CP45&#95;F, CP45&#95;F, LED, and control (without treatment). The pH of the gels was assessed, and color (ΔE 00 ) and whiteness index (ΔWI D ) changes were calculated after cycling (T 1 ), and 7 days from bleaching (T 2 ). Enamel surface roughness average (Ra) and Knoop microhardness (kg/mm 2 , %SHR) were evaluated at baseline (T 0 ) at T 1 and T 2. Scanning electron microscopy evaluated the enamel surface morphology at T 2 ., Results: The gels' pH was neutral and CP20 and CP45 exhibited no differences in ΔE 00 and ΔWI D (p>0.05) but LED increased these parameters for CP20&#95;F and CP45. Erosion/abrasion significantly decreased mean kg/mm 2 , and the LED group was the only one not increasing microhardness after bleaching (p>0.05). None of the groups fully recovered the initial microhardness. All groups exhibited %SHR similar to the control (p>0.05) and the increase in Ra was detected only after erosion/abrasion. CP20&#95;F groups exhibited a more preserved enamel morphology., Conclusion: Light irradiation combined with low-concentrated CP gel promoted a bleaching effect comparable to the high-concentrated CP. The bleaching protocols did not adversely impact the surface of early-stage eroded/abraded enamel., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Purpose: To determine caries inhibition potential of conventional and bulk-fill bioactive composites around restorations., Methods: Enamel and dentin blocks were prepared using a diamond saw under water irrigation, finished (SiC, 600- and 800-grit) and polished (SiC 1,200, final polish= 0.2 μm). Blocks were then selected through enamel surface microhardness, and enamel and dentin standard cavities were restored (n=10/group) with conventional bioactive composite (Beautifil II, BTF), bulk-fill bioactive composite (Activa BioACTIVE, ACT), glass-ionomer cement (Ionofil Plus, ION), conventional composite (GrandioSO, GSO), and bulk-fill composite (Admira Fusion X-TRA, ADM). Afterwards, the blocks were subjected to pH cycling: 4 hours in demineralization and 20 hours in remineralization solutions for 7 days, before being cut in the middle. One half was used to calculate the carious lesion area (ΔS) using values obtained by cross-sectional microhardness (CSMH) testing. The other half was submitted to polarized light microscopy (PLM) and scanning electron microscopy (SEM). The % of internal gap formation (GAP) of restorations' replicas were analyzed under SEM. Data were analyzed by ANOVA and Tukey test (α= 5%)., Results: In terms of CSMH, ION group exhibited the lowest ΔS values, with no significant difference to ADM. The composites BTF and ACT were similar to each other (P< 0.05) and to their negative controls (GSO and ADM), respectively. ION showed lower caries formation under PLM, whereas the GSO group presented a greater demineralized area. ION presented the highest % of internal GAP formation. Bioactive composites (BTF and ACT) were similar to their corresponding conventional ones (GSO and ADM) in terms of GAP formation., Clinical Significance: The glass-ionomer cement was more effective in inhibiting the formation of caries lesions around restorations. Because of the glass-ionomer cement's limited application in high load-bearing areas, the conventional bioactive composite would be a promising clinical choice., Competing Interests: The authors declared no conflict of interest. This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) – Finance Code 001. D.P.S. received a research grant by CAPES as part of the PhD Program. B.O.M. received a research grant by the National Council for Scientific and Technological Development - Institutional Scientific Initiation Scholarship Program (PIBIC/CNPq), as part of the scientific initiation program as an undergraduate student., (Copyright©American Journal of Dentistry.)

Objective: To evaluate the effects of simulated gastric acid erosion combined with mechanical toothbrushing abrasion on the mechanical properties, surface topography, and biofilm adhesion of different CAD/CAM materials., Material and Methods: Specimens of zirconia-reinforced lithium silicate glass-ceramic (ZLS), polymer-infiltrated ceramic network (PICN), feldspathic glass-ceramic (FE), and two nanoceramic resins (RK, RG), were submitted to the following challenges: erosion (E), abrasion (A), erosion combined with abrasion (E + A), or remained untreated (control - C). After challenges, flexural strength was evaluated, while microhardness (KHN) and surface roughness (Ra) were tested before and after treatments. The biofilm adhesion (Streptococcus mutans ATCC 700610, Streptococcus sanguinis ATCC 10556 e Candida albicans MYA 2876) was determined by the counting of colonies forming units per milliliters (UFC/mL) after erosive and abrasive challenges., Results: FE showed the lowest flexural strengths, while ZLS and RG exhibited the highest, while PICN and RK, had intermediate values. PICN, ZLS, and FE showed lower microhardness after E and E + A challenges than polymer-based materials (RG and RK). FE surface roughness increased after E and E + A challenges and after A and E + A challenges for RK. Biofilm formation after erosive/abrasive challenges was higher on ZLS than FE, RK, and RG, but no different than PICN. RK and RG exhibited the lowest biofilm formation among the groups. Furthermore, E + A challenges held significant changes in the surface of the materials, which were more severe on the surface of glass ceramics and hybrid materials., Conclusion: Erosive challenges combined with abrasion negatively influenced the mechanical properties and surface topography of most CAD/CAM materials and increased the biofilm adhesion on ZLS. Besides, the severity of the damage is related to the type and composition of each material., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Experimental adhesives containing co-doped metaloxide nanoparticles were demonstrated to display strong and long-term antibacterial properties against Streptococcus mutans biofilms. The present study represents an effort to characterize the shear-bond strength (SBS) and color stability (CS) of these novel biomaterials. Experimental adhesives were obtained by dispersing nitrogen and fluorine co-doped titanium dioxide nanoparticles (NF&#95;TiO2, 10%, 20% or 30%, v/v%) into OptiBond Solo Plus (OPTB). Dentin surfaces were wet-polished (600-Grit). Specimens (n = 5/group) of Tetric EvoCeram were fabricated and bonded using either OPTB or experimental (OPTB + NF&#95;TiO2) adhesives. Specimens were stored in water (37 °C) for twenty-four hours (T1), three months (T2), and six months (T3). At T1, T2, or T3, specimens were removed from water storage and were tested for SBS. Disc-shaped specimens (n = 10/group; d = 6.0 mm, t = 0.5 mm) of adhesives investigated were fabricated and subjected to thermocycling (10,000 cycles, 5−55 °C, 15 s dwell time). Specimens’ colors were determined with a VITA Easyshade® V spectrophotometer (after every 1000 cycles). SBS data was analyzed using two-way ANOVA and post-hoc Tukey tests, while CS data was analyzed using one-way ANOVA and post-hoc Tukey tests (α = 0.05). Mean values of SBS ranged from 16.39 ± 4.20 MPa (OPTB + 30%NF&#95;TiO2) to 19.11 ± 1.11 MPa (OPTB), from 12.99 ± 2.53 MPa (OPTB + 30% NF&#95;TiO2) to 14.87 ± 2.02 (OPTB) and from 11.37 ± 1.89 (OPTB + 20% NF&#95;TiO2) to 14.19 ± 2.24 (OPTB) after twenty-four hours, three months, and six months of water storage, respectively. Experimental materials had SBS values that were comparable (p > 0.05) to those from OPTB independently of nanoparticle concentration or time-point considered. Experimental materials with higher NF&#95;TiO2 concentrations had less intense color variations and were more color stable than OPTB even after 10,000 thermocycles. In combination, the results reported have demonstrated that experimental adhesives can establish strong and durable bonds to human dentin while displaying colors that are more stable, thereby suggesting that the antibacterial nanotechnology investigated can withstand the harsh conditions within the oral cavity without compromising the esthetic component of dental restorations.

The present study reports on the development and testing of novel bleaching agents containing co-doped metaloxide nanoparticles (NP; 0%, 5%, 10% v/w) and hydrogen peroxide (HP, 0%, 6%, 15%, and 35%). Bovine blocks (n = 200, A = 36 mm2) were obtained and randomly distributed into experimental groups (n = 10/group). NPs were incorporated into gels before bleaching (3 sessions, 7 days apart, 30 min/session, irradiated with violet light-LT). Color changes (ΔE00, ΔWID), mineral content (CO32−, PO43−), and topography were assessed (spectrophotometer, ATR-FTIR, and AFM) before and after bleaching procedures (14 days). Metabolic status and three-dimensional components of non-disrupted Streptococcus mutans biofilms were investigated using a multimode reader and confocal microscopy. The results indicate that ΔE00 and ΔWID significantly increased with NPs’ concentrations and LT. The enamel’s mineral ratio was adversely impacted by HP, but alterations were less pronounced when using NP-containing gels. The enamel’s topography was not damaged by the bleaching protocols tested. The bioluminescence results show that bleaching protocols do not render latent antibacterial properties to enamel, and the confocal microscopy results demonstrate that the 3-dimensional distribution of the components was affected by the protocols. The proposed nanotechnology improved the bleaching efficacy of experimental materials independent of hydrogen peroxide or irradiation and did not adversely impact the enamel’s surface properties or its chemical content.

Objectives: This study characterized a violet LED light (V-LED; bright max whitening) tooth whitening device and evaluated its efficacy on stained enamel compared to hydrogen peroxide (HP)., Materials and Methods: Characterization of the V-LED beam profile was performed using a laser beam-profiler. The irradiance was measured throughout an exposure cycle at 0- and 8-mm distances using an integrating sphere and a spectral radiometer. Bovine enamel/dentin blocks stained with black tea (BT), cigarette smoke (CS), or without staining (CONT) were subjected to V-LED or 40% HP (n = 10/group). Color parameters (ΔL, Δa, Δb, and ΔE 00 ) were measured using a digital spectrophotometer. Light transmission was estimated through 1-mm-thick bovine enamel slices (n = 5). ΔL, Δb, ΔE 00 , and irradiance were analyzed by two-way ANOVAs and Tukey's tests, Δa by Kruskal-Wallis and Mann-Whitney tests, and light transmission by t-test (α = 5%)., Results: Heterogeneous beam distribution was observed for the emitting V-LED chips. After 20 sequential exposures, irradiance levels were reduced 25-50%, regardless of the distance from V-LED. Localized irradiance values were statistically different between beam locations and different distances from the target. V-LED produced lower ΔE 00, ΔL, Δa, and Δb values than HP for CONT and BT, with no differences for CS. Light transmittance decreased approximately 98% through 1-mm thick enamel., Conclusions: V-LED irradiance was heterogeneous and decreased throughout the exposure cycles and was also greatly reduced with increasing tip distance. V-LED produced a significantly lower whitening effect on BT and control teeth., Clinical Relevance: This study contributes to the knowledge of V-LED and its clinical use., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

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 (ΔE ab ), subjective (ΔSGU) color changes, and absolute risk of tooth sensitivity (TS). Heterogeneity was evaluated using Q test (I 2 ). 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 ΔE ab , ΔSGU, and TS. ΔE ab exhibited substantial heterogeneity (I 2  = 87%), while ΔSGU (I 2  = 60%) and the TS (I 2  = 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., (© 2021 Wiley Periodicals LLC.)

Objectives: To evaluate the biaxial flexural strength (BFS), flexural modulus (BFM), and Knoop microhardness (KHN) of incremental and bulk-filled resin-based composites (RBCs) using extended curing exposure times., Materials and Methods: Disc specimens (n = 8; 6-mm diameter) were fabricated using three stacked molds (0.5-mm thick for the top and bottom molds, and a 1-mm-thick center mold for the conventional and 3-mm thick for the bulk-fill RBCs). Conventional (Tetric EvoCeram/TCE and Filtek Z250/FIZ) and bulk-fill RBCs (Tetric EvoCeram Bulk Fill/TBF and Filtek One Bulk Fill Restorative/FOB) were evaluated. The stacked RBC-filled molds were light-cured for (1) the manufacturer-recommended exposure (MRE) duration; (2) 50%, and (3) 100% extension of the MRE. The BFS, BFM, and KHN of the top and bottom discs were measured. BFS and BFM were analyzed by three-way ANOVA (material*curing time*depth) and Tukey's post hoc (α = 0.05). KHN was analyzed by two-way ANOVA (curing time*depth) and Tukey's post hoc (α = 0.05)., Results: Extending the exposure duration did not change the BFS and BFM on the top of the RBCs, but the BFS and KHN increased at the bottom of bulk-fill RBCs. For the conventional RBCs, TCE showed the highest increase on BFS at the bottom, going from 53.6 MPa at T1 to 69.9 at T3. Among the bulk-fill RBCs, FOB presented the highest increase on the bottom BFS (T1: 101.0 ± 19.9 MPa, T3: 147.6 ± 12.9 MPa). For all RBCs and exposure times, BFS and KHN were lower at the bottom. Only FIZ and FOB reached a bottom-to-top hardness ratio of 80%, at T3 and T2., Conclusion: A significant increase on the BFS and KHN on the bottom of bulk-fill RBCs can be observed when the time of exposure to the curing light is double the MRE. However, extended exposure does not eliminate differences on the BFS and KHN between the shallow and deep regions of RBCs. TCE and TBF failed to reach an acceptable B/T hardness ratio at all evaluated exposure times., Clinical Relevance: Mechanical properties of RBCs can be affected by insufficient polymerization, specially at deeper regions of the increment. Therefore, clinicians should consider applying twice the MRE to curing-light to polymerize the maximal increment thickness of bulk-fill RBCs., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objectives: To evaluate the long-term outcomes of in-office bleaching with violet LED light (LED) alone or combined with carbamide (CP) or hydrogen (HP) peroxides., Methods: Volunteers of a previous short-term study were recalled for 6- and 12-month follow-ups, according to the following interventions (n = 18/group): LED, CP, LED/CP, HP, and LED/HP. The objective color (ΔE ab , ΔE 00 ) and whiteness index (ΔWI D ) changes were calculated applying the CIELab coordinates' values obtained using a spectrophotometer. A visual shade guide determined the tooth's subjective color change (ΔSGU). Data were submitted to one-way ANOVA or Welch's ANOVA, following appropriate post hoc tests (α = 5%)., Results: The LED and CP groups exhibited the lowest ΔE ab , ΔE 00 , and ΔSGU (p < 0.05), but the LED group displayed a significantly lower ΔWI D . After 12 months, the LED/CP group presented a higher ΔE ab and ΔE 00 than the CP group (p < 0.05). ΔE ab , ΔE 00 , ΔSGU, or ΔWI D means did not differ statistically between the LED/CP and HP groups. The LED/HP group presented a higher ΔE 00 than the HP group, regardless of the time., Conclusions: The bleaching efficacy of LED alone was significantly lower compared to the LED/CP and HP-containing protocols. After 12 months, the LED/CP and HP groups did not differ in bleaching efficacy. LED irradiation only increased the objective color change of bleaching gels., Clinical Relevance: LED alone promoted a long-term perceptible bleaching, but not compatible with that of high-concentrated HP. The bleaching outcomes of violet irradiation to 37% CP were maintained over time, with LED/CP demonstrating comparable results to HP even after 12 months., National Clinical Trials Registry (rebec): RBR-5t6bd9., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objectives: To evaluate the bleaching efficacy of a violet radiation (VR) combined or not with bleaching gels on the color and mineral content of stained teeth., Material and Methods: Enamel/dentin blocks were obtained and stained (n = 50) with coffee, red wine, tobacco smoke, or were left non-stained. The stained or not-stained blocks (n = 10) were distributed into five bleaching groups (n = 10): VR, CP (37 % carbamide peroxide), VR/CP, HP (35 % hydrogen peroxide), and VR/HP. Color (ΔE 00, ΔL, Δa, and Δb) and whiteness index (ΔWI D ) changes were evaluated after staining and after bleaching using a spectrophotometer. Calcium (Ca), phosphorous (P), and Ca/P contents (in wt%) were measured after bleaching using energy-dispersive X-ray spectroscopy (EDS). Data was statistically analyzed (α = 0.05) using two-way ANOVA and Tukey tests (ΔE 00, ΔWI D , ΔL, Δb, wt%) or Kruskal-Wallis and Dunn tests (Δa)., Results: VR alone caused higher colorimetric changes on coffee, tobacco and red wine-stained groups compared to non-stained enamel (p < 0.05). VR/CP exhibited higher colorimetric changes compared to CP in coffee and non-stained groups. The VR/CP, HP and VR/HP groups exhibited no change differences (p > 0.05). No differences were observed for the wt% of Ca, P and Ca/P between the groups., Conclusions: The violet radiation was more effective in bleaching stained rather than non-stained teeth. VR combined with 37 % carbamide peroxide was as effective as the HP agent. Besides, no adverse effects could be observed in the enamel mineral content, regardless of the bleaching protocol tested, according to the EDS semi-quantitative analysis., (Copyright © 2021 Elsevier B.V. All rights reserved.)

This review compiles the literature on the antioxidants used after tooth bleaching with either low or high-concentrated carbamide and hydrogen peroxide to recover the bond strength. Antioxidants used in bleached teeth are mainly natural and non-enzymatic, except for catalase. Commonly, antioxidants are applied to remove any reactive oxygen species (ROS) residues left from bleaching gels, which adversely affect adhesive procedures, such as restorations or orthodontic brackets bonding. Even though sodium ascorbate, the most thoroughly investigated antioxidant, showed the most efficient bond strength recovery at 10% concentration, its performance depends on the type of solution and the application time. Natural extracts, such as proanthocyanidins and green tea, showed satisfactory results in the reversal of bond strength at 5% and 10% concentrations, respectively. Sodium ascorbyl phosphate, α-tocopherol, and catalase exhibited promising results, but further research is required. The adhesive system type plays an important role in the outcome of enamel bond strength after the antioxidant application. The postponement of either restorations or orthodontic brackets cementation following bleaching procedures seems to be efficiently replaced by antioxidant application prior to bonding procedures. However, the efficacy of using an antioxidant to recover bond strength depends on its type and application time., (© 2021 European Journal of Oral Sciences.)

Aim: To evaluate the effects of activated charcoal powder (COAL) combined with regular (RT) or whitening (WT) toothpastes on enamel color and surface in comparison to carbamide peroxide (CP)., Methods: Dental blocks (n = 10/group) were randomly divided into COAL, COAL/RT, COAL/WT, CP, CP/RT, CP/WT, RT, WT, and CONT (without treatment). Simulated toothbrushing and whitening treatments were followed by colorimetric (ΔE 00 , L*, a*, b*), surface roughness (Ra), and enamel topography assays. ΔE 00 was submitted to two-way ANOVA and Tukey test. Color coordinates and Ra were tested with three-way repeated measures ANOVA (α = 5%)., Results: COAL exhibited greater ΔE 00 than CONT (P = .048), but it did not enhance ΔE 00 promoted by RT or WT (P > .05). COAL alone increased Ra (P < .001) and altered enamel topography. COAL did not increase Ra caused by RT and WT (P > .05). CP exhibited the highest ΔE 00 (P < .05), but it raised Ra and changed enamel topography to a less extent than COAL., Conclusion: Even though charcoal powder did not increase enamel Ra when combined with toothpastes, the topography was negatively impacted by COAL. Also, COAL was unable to enhance the color change of RT and WT, or reach the effectiveness of CP., Clinical Significance: The use of activated charcoal-based product, claimed as a natural whitener, before brushing with toothpastes is not only ineffective to change the color of teeth, but also it might result in alterations on the enamel surface. Whitening with CP, instead, was effective during the same period of treatment, which still represents a more appropriate technique to whiten teeth., (© 2020 Wiley Periodicals LLC.)

Aim: This in vitro study assessed the effects of in-office bleaching with gels (35% hydrogen peroxide [HP] or 37% cabamide peroxide [CP]) and two activation sources (violet radiation [LED] or nonthermal atmospheric plasma [NTAP]) on the mineral content of bovine enamel., Material and Methods: Dental blocks (n = 90) were assessed for initial microhardness before random distribution into nine groups: LED, LED + HP, LED + CP, NTAP, NTAP + HP, NTAP + CP, HP, CP and control (without treatment). Specimens were subjected to bleaching (2 clinical sessions, 7 days apart) using LED [20x/session, 1-min/each, 30 s apart] or NTAP [1x/session, 10 min]. μRaman determined contents of phosphate (PO 4 3 ) and carbonate (CO 3 2 ). Micro-energy dispersive X-ray fluorescence (μEDXRF) and spectrophotometry of enamel microbiopsy evaluated the calcium to phosphorous ratios (Ca/P). Two-way ANOVA and Tukey tests analyzed μRAMAN and μEDXRF results. Spectrophotometry results were analyzed using Kruskal-Wallis and Dunn tests. Pearson correlation tested μEDXRF and spectrophotometry results (α = 5%)., Results: NTAP and NTAP + HP exhibited greater PO 4 3- content than LED, LED + HP and control (p < 0.05). No statistical differences were detected between CO 3 2- among groups. While μEDXRF evaluation demonstrated that NTAP and LED did not alter Ca/P ratio of enamel (p > 0.05), spectrophotometry showed that Ca/P reduced for LED + HP (p < 0.05). No correlation was found between μEDXRF and enamel microbiopsy spectrophotometry (p > 0.05)., Conclusions: Activation sources did not adversely impact enamel's phosphate and carbonate concentrations after specimens' exposure to bleaching gels (either HP or CP). Visible light radiation emitted by a LED source was shown to adversely impact specimens' Ca/P ratios when treated with HP-containing bleaching gels., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Objective This study evaluated the clinical effect of violet LED light on in-office bleaching used alone or combined with 37% carbamide peroxide (CP) or 35% hydrogen peroxide (HP). Methodology A total of 100 patients were divided into five groups (n=20): LED, LED/CP, CP, LED/HP and HP. Colorimetric evaluation was performed using a spectrophotometer (ΔE, ΔL, Δa, Δb) and a visual shade guide (ΔSGU). Calcium (Ca)/phosphorous (P) ratio was quantified in the enamel microbiopsies. Measurements were performed at baseline (T 0 ), after bleaching (T B ) and in the 14-day follow-up (T 14 ). At each bleaching session, a visual scale determined the absolute risk (AR) and intensity of tooth sensitivity (TS). Data were evaluated by one-way (ΔE, Δa, ΔL, Δb), two-way repeated measures ANOVA (Ca/P ratio), and Tukey post-hoc tests. ΔSGU and TS were evaluated by Kruskal-Wallis and Mann-Whitney, and AR by Chi-Squared tests (a=5%). Results LED produced the lowest ΔE (p<0.05), but LED/HP promoted greater ΔE, ΔSGU and Δb (T 14 ) than HP (p<0.05). No differences were observed in ΔE and ΔSGU for LED/CP and HP groups (p>0.05). ΔL and Δa were not influenced by LED activation. After bleaching, LED/CP exhibited greater Δb than CP (p>0.05), but no differences were found between these groups at T 14 (p>0.05). LED treatment promoted the lowest risk of TS (16%), while HP promoted the highest (94.4%) (p<0.05). No statistical differences of risk of TS were found for CP (44%), LED/CP (61%) and LED/HP (88%) groups (p>0.05). No differences were found in enamel Ca/P ratio among treatments, regardless of evaluation times. Conclusions Violet LED alone produced the lowest bleaching effect, but enhanced HP bleaching results. Patients treated with LED/CP reached the same efficacy of HP, with reduced risk and intensity of tooth sensitivity and none of the bleaching protocols adversely affected enamel mineral content.

Objective: The aim is to evaluate the effect of violet light (VL) and nonthermal atmospheric plasma (NTAP) combined with or without 35% hydrogen peroxide (HP) and 37% carbamide peroxide (CP)., Methods: Bovine crowns were divided into (n = 10) VL, VL/HP, VL/CP, NTAP, NTAP/HP, NTAP/CP, HP, CP, and C (control) groups. Color and whiteness change (CIELAB-Δ E ab, CIEDE2000-Δ E 00 , whiteness index-ΔWI D ), color parameters (ΔL, Δa, and Δb), and intrapulpal concentration (μL/mL) of HP were assessed by spectrophotometry. Scanning electron microscopy evaluated the morphology of enamel surface. Data were analyzed by two-way analysis of variance and Tukey (Δ E ab , ΔE 00 , ΔWI D , ΔL, and μL/mL) and Kruskal-Wallis and Mann-Whitney tests (Δ a and Δ b, α = 5%)., Results: VL increased ΔE ab and ΔWI D of CP (P < .05). VL and NTAP alone resulted in perceptible color and whiteness change, but lower than those in the gel-treated groups (P < .05). Activation modes increased ΔL compared with that of C, but only VL enhanced Δb when applied alone or combined with CP. VL and NTAP did not increase HP diffusion (P > .05) or cause alterations in enamel morphology. However, HP and CP promoted topographical changes., Conclusion: VL and NTAP changed color to a lesser extent than bleaching gels. VL produced supplementary effectiveness only for CP (ΔE ab and ΔWI D ), without increasing HP diffusion or changing enamel morphology., Clinical Significance: Although violet LED light and nonthermal atmospheric plasma (NTAP) promoted in vitro perceptible bleaching without compromising enamel morphology, bleaching gels (hydrogen peroxide and carbamide peroxide) were more effective than VL or NTAP. VL or NTAP did not increase intrapulpal diffusion of peroxide., (© 2019 Wiley Periodicals, Inc.)

Objective: High concentrations of hydrogen peroxide can cause adverse effects on composition and structure of teeth. However, the addition of calcium and fluoride in bleaching agents may reduce enamel demineralization. To evaluate chemical changes of sound and demineralized enamels submitted to high concentrations of hydrogen peroxide containing fluoride (F) or calcium (Ca)., Material and Methods: Enamel blocks of bovine incisors with standard dimensions were obtained and half of them were submitted to pH-cycling to promote initial enamel caries lesions. Sound and demineralized enamel samples were divided into (n=10): (C) Control (no whitening treatment); (HP) 35% hydrogen peroxide; and two experimental groups: (HPF) 35% HP+0.2% F and (HPC) 35% HP+0.2% Ca. Experimental groups were submitted to two in-office bleaching sessions and agents were applied 3 times for 15 min to each session. The control group was kept in remineralizing solution at 37°C during the bleaching treatment. The surface mineral content of sound and demineralized enamels was determined through Fourier Transform Raman spectroscopy (FT-Raman), Energy dispersive Micro X-ray fluorescence spectroscopy (μ-EDXRF); and the subsurface, through cross-sectional microhardness (CSMH). In addition, polarized light microscopy (PLM) images of enamel subsurface were observed., Results: According to three-way (FT-Raman and μ-EDXRF analyses) or two-way analysis of variance (ANOVA) (CSMH) and Tukey test (α=5%), the calcium or fluoride added to high-concentrated bleaching agents increased phosphate and carbonate concentrations on sound and demineralized enamels (p<0.05). However, HPC and HPF were unable to completely reverse the subsurface mineral loss promoted by bleaching on sound and demineralized enamels. The calcium/ phosphate (Ca/P) ratio of sound enamel decreased after HP treatment (p<0.001)., Conclusion: Even though experimental bleaching agents with Ca or F reduced mineral loss for both sound and demineralized enamel surfaces, these agents were unable to reverse the enamel subsurface demineralization.

The formation of networks through light-initiated radical polymerization allows little freedom for tailored network design. The resulting inhomogeneous network architectures and brittle material behavior of such glassy-type networks limit the commercial application of photopolymers in 3D printing, biomedicine, and microelectronics. An ester-activated vinyl sulfonate ester (EVS) is presented for the rapid formation of tailored methacrylate-based networks. The chain transfer step induced by EVS reduces the kinetic chain length of the photopolymer, thus shifting the gel point to higher conversion, which results in reduced shrinkage stress and higher overall conversion. The resulting, more homogeneous network is responsible for the high toughness of the material. The unique property of EVS to promote nearly retardation-free polymerization can be attributed to the fact that after the transfer step no polymerizable double bond is formed, as is usually seen in classical chain transfer agents. Laser flash photolysis, theoretical calculations, and photoreactor studies were used to elucidate the fast chain transfer reaction and exceptional regulating ability of EVS. Final photopolymer networks exhibit improved mechanical performance making EVS an outstanding candidate for the 3D printing of tough photopolymers., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Attempts to understand the mechanical behavior of dentin and other mineralized tissues have been primarily focused on the role of their more abundant matrix components, such as collagen and hydroxyapatite. The structural mechanisms endowing these biological materials with outstanding load bearing properties, however, remain elusive to date. Furthermore, while their response to deformation has been extensively studied, mechanisms contributing to their recovery from induced deformation remain poorly described in the literature. Here, we offer novel insights into the participation of proteoglycans (PG) and glycosaminoglycans (GAG) in regulating the nanoindentation creep deformation and recovery of mineralized and demineralized dentin. Accordingly, after the enzymatic digestion of either PGs and associated GAGs or only GAGs, the nanoindentation creep deformation of dentin increased significantly, while the relative recovery of both the mineralized and demineralized dentin dropped by 40-70%. In summary, our results suggest that PGs and GAGs may participate in a nanoscale mechanism that contributes significantly to the outstanding durability of dentin and possibly other mineralized tissues of similar composition., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Highly cross-linked formulations of ultrahigh-molecular-weight polyethylene (XLPE) offer exceptional wear resistance for total joint arthroplasty but are offset with a reduction in postyield and fatigue fracture properties in comparison to conventional ultrahigh-molecular-weight polyethylene (UHMWPE). Oxidation resistance is also an important property for the longevity of total joint replacements (TJRs) as formulations of UHMWPE or XLPE utilizing radiation methods are susceptible to free radical generation and subsequent embrittlement. The balance of oxidation, wear, and fracture properties is an enduring concern for orthopedic polymers used as the bearing surface in total joint arthroplasty. Optimization of material properties is further challenged in designs that make use of locking mechanisms, notches, or other stress concentrations that can render the polymer susceptible to fracture due to elevated local stresses. Clinical complications involving impingements, dislocations, or other biomechanical overloads can exacerbate stresses and negate benefits of improved wear resistance provided by XLPE. This work examines trade-offs that factor into the use of XLPE in TJR implants., (Copyright © 2013 Wiley Periodicals, Inc.)

Authentic hair samples from Cannabis users and a drug free hair sample which was separately spiked with tetrahydrocannabinol (THC), cannabidiol (CBD) or cannabinol (CBN) were exposed outside as well as to natural sunlight at prevailing and elevated humidity in quartz glass tubes during 8 weeks. In addition, authentic and spiked hair samples were exposed to xenon arc radiation in a light exposure cabinet for 24 hours. Stability of THC, CBD and CBN in authentic samples differed from that of the spiked hair. The radiation experiment revealed that CBN could not be measured in hair which had been spiked with THC. Under all conditions chosen the concentrations of THC, CBD and CBN decreased. At high humidity the concentrations declined more rapidly. In both authentic and spiked samples THC was most unstable compared to CBD and CBN. Therefore, in hair analysis determination of CBD and CBN seems promising to detect Cannabis exposure even under unfavorable conditions.

Due to a few well-publicized stories about patient injury and death, office-based ambulatory surgery has recently been thrust upon the forefront of current discussions about clinical outcomes. This has stimulated interest among ambulatory surgery stakeholders, including physicians, patients, and elected officials. An analysis of medical office-based surgical facilities in Florida indicates that office-based surgeons tend to work independently, with limited peer oversight, although as a whole, they professionally subscribe to a high level of ethical standards and offer patients an expected high quality level of clinical expertise. The results did not definitively indicate a relationship between unaccredited medical offices and unacceptable surgical procedures. The paper concludes by offering fifteen medical office standards that can aid in developing office surgery oversight policies.

Trying to find out the clinical elements that define the precise indication ofr a jejunal biopsy, 28 children with several pathological conditions were studied. They were 12 cases of kwashiorkor, 11 cases with chronic diarrhea, two cases of chronic pancreatitis, 2 cases with ferropenic anemia resistant to the oral treatment with iron and one case of chilous ascitis. It is concluded that only in those cases in which the biopsy is the precise medium for diagnosis is where it would be indicated, such as intestinal lymphangiectasis or in those cases with signs or evidence of malabsorption without diarrhea. The chronic diarrhea per se does not seem to be a formal indication for biopsy.