In situ study of the effect of endogenous and exogenous agents on color stability, hardness, and surface roughness of an elastomer for facial prostheses.

PURPOSE: To evaluate in situ the influence of sweat, oil, sunscreen, and disinfectant solution on the color stability, hardness, and roughness of elastomer for facial prostheses. MATERIALS AND METHODS: Standardized and intrinsically pigmented specimens remained in contact with human skin from the same person for 30 days, considering exposures (n = 36 per group), absent of exposition (Control, C); sweat and oiliness contact (SO); sweat and oiliness associated with sunscreen (SOS); 0.12% chlorhexidine digluconate immersion (CD0.12%); and all agents exposed (SOSCD). The main variables were color change (CIELab and National Standard Bureau system, NBS), Shore A hardness, and surface roughness, measured at baseline and 30 days. Qualitative analyses were performed by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The data were analyzed by Kruskal-Wallis tests (color) and two-way ANOVA (hardness and roughness) with Sidak post-test (α = 0.05). RESULTS: CD0.12% (1.54 ± 0.49) and SOSCD (2.10 ± 1.03) had similar effects and caused the smallest color changes, considered mild and noticeable (NBS), respectively. SOS promoted the greatest color change (6.99 ± 1.43, NBS: large) and hardness (17.97 ± 0.56); SOS promoted intermediate roughness (3.48 ± 1.05) between SOSCD (2.25 ± 0.53), and two similar groups: C (4.46 ± 0.95), and CD0.12% (4.39 ± 1.26). The qualitative analysis showed an irregular, dense, dry, and whitish layer on the surface of the specimens exposed to sunscreen, which was reduced when in contact with 0.12% chlorhexidine digluconate. CONCLUSIONS: Endogenous and exogenous factors are capable of altering elastomer properties. The 0.12% chlorhexidine digluconate minimized the changes caused by sweat, oil, and sunscreen.

A Global Overview on Electronic Apex Locator Use From 1968 to 2023: A Bibliometric Analysis.

INTRODUCTION: This bibliometric review analyzed the research trends and main characteristics of articles related to Electronic Apex Locators (EALs). METHODS: The search was conducted in November 2023 on the Web of Science Core Collection. Narrative and systematic reviews, observational and intervention studies, laboratory, and clinical studies were included. Two researchers selected the articles and extracted the number of citations, year of publication, journal, study design, theme, country, continent, institutions, author, and keywords. Collaborative networks were generated using the VOSviewer software. The relationship between data were determined by Spearman's correlation. RESULTS: The search resulted in 374 articles, of which 294 were included. Most cited article had 175 citations. The most prevalent journal was the Journal of Endodontics (n = 84). The predominant study design was the laboratory-based (n = 223). The predominant theme was the EALs accuracy (n = 175). Piasecki L was the author with the highest number of articles (n = 11). Only 8.16% of the studies were conducted in deciduous teeth. The country with the most studies was Brazil (n = 46). Asia (n = 107) was the continent with the highest number of publications. There was a weak positive correlation between the number of citations and impact factor (rho = .294), and a strong negative correlation between citations and year of publication (rho = -.710). CONCLUSIONS: The majority of articles were laboratory-based studies conducted on permanent teeth, focusing on the accuracy of EALs. Future studies should prioritize research on deciduous teeth, systematic reviews, and, notably, clinical trials.

Ocimum basilicum essential oil in pacu Piaractus mesopotamicus: anesthetic efficacy, distribution, and depletion in different tissues.

This study aimed to evaluate the anesthetic activity of Ocimum basilicum essential oil and the distribution and depletion of its major compounds in different tissues of the pacu, Piaractus mesopotamicus. Juveniles (319.08 ± 9.14 g) were individually anesthetized with six concentrations of essential oil from O. basilicum (150, 180, 210, 240, 270, and 300 mg L-1), while in a second experiment, fish (492.39 ± 51.51 g) were subjected to a 10 min immersion bath with essential oil from O. basilicum (300 mg L-1). After anesthetic recovery, blood and tissue samples of the brain, gills, liver, spleen, and white muscle were collected at 0, 0.5, 1.0, 3.0, 6.0, 12.0, and 24 h. A 300 mg L-1 concentration induced anesthesia in the shortest time (193.11 ± 9.31), while at 270 and 300 mg L-1 concentrations, the anesthetic recovery period was the longest (244.33 ± 12.44) Methyl chavicol and linalool were quantified in all tissue samples. The plasma concentrations of methyl chavicol differed (p < 0.05) at all evaluated times. Linalool decreased (p < 0.05) from 0 to 1 h and decreased again only after 12 h. Reduction percentages in 24 h were 92.9% for methyl chavicol, and 97.2% for linalool. Elimination of the compounds methyl chavicol and linalool is slower in the gills, where lower elimination constants (0.03 and 0.15 per h) and longer half-lives (25.84 and 4.53 h), respectively, are noted. In general, essential oil from O. basilicum compounds was readily eliminated, showing promising potential for use as an anesthetic in aquaculture.

Development of functional fillers as a self-healing system for dental resin composite.

OBJECTIVES: To evaluate the incorporation of repairing capsules containing different monomers and polymerization modulators on the self-healing efficiency of an experimental photopolymerizable resin-based composite. METHODS: Self-healing capsules containing different monomers and polymerization modulators were prepared by emulsion polymerization: TCDHEPT (TEGDMA and DHEPT), BTCDHEPT (Bis-GMA, TEGDMA, and DHEPT), and BTCBPO (Bis-GMA, TEGDMA, and BPO). The capsules were analyzed through Fourier transform infrared spectroscopy and scanning electron microscopy. The capsules were added into experimental photopolymerizable resin composites establishing the following groups: ER (Control without capsules), ER+BPO, ER+BPO+TCDHEPT, and ER+BTCBPO+BTCDHEPT. Filtek Z350 resin composite (3 M ESPE) was used as a commercial reference. The materials were tested for degree of conversion (DC), flexural strength (σf), elastic modulus (Ef), fracture toughness (virgin KIC), self-healing efficiency (healed KIC), and roughness. For statistical analysis, the significance value was established at an a = 0.05 level. RESULTS: When compared to the control material, the incorporation of repairing capsules did not affect DC, σf, and Ef. Fracture toughness was statistically similar between the experimental groups (p ≤ 0.05). Healed KIC was statistically different between the groups ER+TCDHEP and ER+BTCBPO+BTCDHEPT; the self-healing efficiency was higher for ER+TCDHEPT. Surface roughness was statistically similar among all groups. CONCLUSIONS: The use of self-healing capsules promoted repair of the material. Studies with material aging after the self-healing process are necessary to better demonstrate the effectiveness of this system. CLINICAL SIGNIFICANCE: The self-healing system seemed to be a promising technology to be used in self-repaired restorative materials, which may prevent restoration fractures.

Novel polymethyl methacrylate modified with metal methacrylate monomers: biological, physicomechanical, and optical properties.

This study sought to evaluate the physical and antimicrobial properties of a thermopolymerizable acrylic resin (PMMA) modified with metallic methacrylate monomers -zirconia (ZM), tin (TM), and di-n-butyl (DNTMB) methacrylates. Color stability was evaluated before and after immersion of samples in a staining solution by a digital spectrophotometer. The mechanical brushing test was evaluated by the roughness test. The flexural strength test used a mechanical testing machine. Human keratinocytes were used to assess cell viability and the biofilm formation assay was carried out for 5 days, in a microcosms model after one year of specimen storage. For statistical analysis, the method chosen was based on adherence to the normal distribution model and equality of variances (p < 0.05). The addition of DNTMB to PMMA promoted great antimicrobial action, acceptable cytocompatibility, without hampering the physical-mechanical properties of the commercial material. Therefore, the modified PMMA proved to be a promisor alternative to conventional resins.This study sought to evaluate the physical and antimicrobial properties of a thermopolymerizable acrylic resin (PMMA) modified with metallic methacrylate monomers -zirconia (ZM), tin (TM), and di-n-butyldimethacrylate-tin (DNTMB) methacrylates. Color stability was evaluated before and after immersion of samples in a staining solution using a digital spectrophotometer. The mechanical brushing test was evaluated by the roughness test. The flexural strength test used a mechanical testing machine. Human keratinocytes were used to assess cell viability and the biofilm formation assay was carried out for 5 days in a microcosm model after one year of specimen storage. For statistical analysis, the method chosen was based on adherence to the normal distribution model and equality of variances (p < 0.05). The addition of DNTMB to PMMA promoted great antimicrobial action, acceptable cytocompatibility, without hampering the physical-mechanical properties of the commercial material. Therefore, the modified PMMA proved to be a promising alternative to conventional denture base resins for dental use.

Novel cinnamon-laden nanofibers as a potential antifungal coating for poly(methyl methacrylate) denture base materials.

OBJECTIVES: To modify the surface of denture base material by coating it with cinnamon-laden nanofibers to reduce Candida albicans (C. albicans) adhesion and/or proliferation. MATERIALS AND METHODS: Heat-cured poly(methyl methacrylate) (PMMA) specimens were processed and coated, or not, with cinnamon-laden polymeric nanofibers (20 or 40 wt.% of cinnamon relative to the total polymer weight). Scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) analyses of the nanofibers were performed. Antifungal activity was assessed through agar diffusion and colony-forming unit (CFU/mL) assays. Representative SEM morphological analysis was carried out to observe the presence/absence of C. albicans on the fibers. Alamar blue assay was used to determine cell toxicity. Analysis of variance and the Tukey's test were used to analyze the data (α = 0.05). RESULTS: SEM imaging revealed nanofibers with adequate (i.e., bead-free) morphological characteristics and uniform microstructure. FTIR confirmed cinnamon incorporation. The cinnamon-laden nanofibers led to growth inhibition of C. albicans. Viable fungal counts support a significant reduction on CFU/mL also directly related to cinnamon concentration (40 wt.%: mean log 6.17 CFU/mL < 20 wt.%: mean log 7.12 CFU/mL), which agrees with the SEM images. Cinnamon-laden nanofibers at 40 wt.% led to increased cell death. CONCLUSIONS: The deposition of 20 wt.% cinnamon-laden nanofibers onto PMMA surfaces led to a significant reduction of the adhesive and/or proliferative ability of C. albicans, while maintaining epithelial cells' viability. CLINICAL RELEVANCE: The high recurrence rates of denture stomatitis are associated with patient non-adherence to treatments and contaminated prostheses use. Here, we provide the non-patients' cooperation sensible method, which possesses antifungal action, hence improving treatment effectiveness.

Bixa orellana L. (Achiote, Annatto) as an antimicrobial agent: A scoping review of its efficiency and technological prospecting.

ETHNOPHARMACOLOGICAL RELEVANCE: Bixa orellana L. is reported to have numerous applications in traditional medicine and pharmacological properties such as wound healing, analgesic, hemostatic, and antioxidant activities. Recently, the literature has shown scientific interest of its antimicrobial properties aiming the development of cost-effective phytotherapeutic agents. However, no literature are available in witch the antimicrobial and technological prospecting are summarized. AIM OF STUDY: This study aimed to systematically review articles and patents related to the antimicrobial activity of B. orellana. METHODS: The review followed the guidelines proposed by The Joanna Briggs Institute and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Two reviewers performed a literature search up to November 2021 in eight databases: Medline (PubMed), Scopus, Scifinder, Web of Science, Cochrane, Embase, Scielo, and Biblioteca Virtual em Saúde. The following databases for the patent search were analyzed: United States Patent and Trademark Office (USPTO), Google Patents, National Institute of Industrial Property (INPI), World Intellectual Property Organization (WIPO), and Espacenet (European Patent Office, EPO). The grey literature was searched using the ProQuest Dissertations and Periódicos Capes Theses database. The methodological quality and risk of bias in the included studies were carried out using Review Manager (RevMan) 5.3.5. RESULTS: After analyzing the 47 studies and five patents fulfilled all the criteria and were included in the present investigation. The evidence suggests that this herbal medicine is effective against several fungi, Gram-positive and Gram-negative bacteria, being more effective to Gram-negative bacteria. Regarding the risk of bias and methodological quality analysis, most studies a high risk of bias related to random sequence generation and allocation concealment. CONCLUSION: Up to now, the evidence in the literature suggests that the use of B. orellana preparations for antimicrobial preparations has some effectiveness. However, further research is needed using standard B. orellana preparations to determine their effectiveness as antimicrobial agents and expanding their application at an industrial level, in addition in vivo studies are needed for this confirmation.

Antimicrobial and physical properties of experimental endodontic sealers containing vegetable extracts.

To assess the antimicrobial activity and the physical properties of resin-based experimental endodontic sealers with the incorporation of vegetable extracts obtained from Bixa orellana, Mentha piperita, and Tagetes minuta species. The extracts were obtained and characterized by gas chromatography-mass spectrometry (GC-MS), and minimum inhibitory concentration (MIC) against Streptococcus mutans, Enterococcus faecalis, and Candida albicans. The extracts were individually incorporated into a dual-cure experimental sealer at a mass concentration of 0.5%. A commercial reference RealSeal was used. The sealers were evaluated by measuring the setting time, degree of conversion, dimensional stability, radiopacity, flow, and film thickness of these materials, also and its antimicrobial effect was evaluated using the direct contact test. Data were statistically analyzed by analysis of variance and Tukey's post-hoc test at α = 0.05 significance level. The physical properties were not influenced by the addition of the vegetable extracts (p > 0.05). For S. mutans, only T. minuta and B. orellana groups presented antibacterial activity after 24 h of contact (p < 0.05). All extracts evidenced an antibacterial effect against E. faecalis (p < 0.05). The experimental sealers hold promise as a novel vegetable sealer with great antimicrobial activity and also great physical-mechanical properties. Nonetheless, more studies are needed.

In vitro efficacy of commercial and experimental proteolytic enzyme-based whitening dentifrices on enamel whitening and superficial roughness.

OBJECTIVE: To evaluate the whiteness index (WID ) and surface roughness (Ra) of bovine enamel after simulated tooth brushing with different commercial and experimental whitening dentifrices. MATERIALS AND METHODS: Cylindrical enamel bovine specimens were acid etched, stained, and divided in nine groups (n = 8): Colgate® Optic White®, Crest® Baking Soda and Peroxide, Arm and Hammer® Advanced White™ Extreme Whitening, Rembrandt® Deeply White® + Peroxide, Close up® White Attraction Natural Glow, Hinode Prowhite, and experimental dentifrice containing papain (PP), bromelain (PB), or papain and bromelain (PPB). Ra and WID were obtained initially and after 600, 1200, and 3,600 cycles of simulated tooth brushing. Data were analyzed using two-way analysis of variance test (α = 0.05). RESULTS: Ra was significantly influenced by both dentifrice (p = 0.043) and period of tooth-brushing simulation (p < 0.001). Except for PP and PPB, all groups showed a statistically significant increase in Ra after simulated tooth brushing. After staining and brushing, none of the materials tested increased the initial WID . CONCLUSIONS: The effect of commercial whitening dentifrices may be related to their high abrasiveness. Experimental formulations tested provided a similar effect without undesired wear of enamel. Whitening dentifrices only act through an abrasive effect rather than bleaching the tooth structures. When used, special care must be taken for avoid undesired wear of enamel. Experimental dentifrices provided similar removal of extrinsic stains without undesired abrasiveness; however, this effect may be due to the use of less aggressive abrasives in their formulations.

Novel in-office peroxide-free tooth-whitening gels: bleaching effectiveness, enamel surface alterations, and cell viability.

To evaluate the bleaching ability, the effect on enamel surface and cytotoxicity of novel tooth-whitening formulations containing papain, ficin, or bromelain. Forty bovine dental discs (6 cm ×4 cm) were pigmentated and randomly allocated into the following groups (n = 10): Group 1, 20 wt% carbamide peroxide (control); group 2, 1% papain-based whitening; group 3, 1% ficin-based whitening; and group 4, 1% bromelain-based whitening. The whitening gels were prepared and applied on the enamel three times per day once a week, for 4 weeks. Color measurement was obtained by CIEDE2000. Enamel Knoop microhardness and roughness were evaluated. The WST-1 assay was used to evaluate the cell viability of mouse fibroblast cells (L929). Data were statistically analyzed by one-way analysis of variance (ANOVA) and Student Newman Keuls's post hoc test at α = 0.05 significance level. Bromelain, ficin-based, and carbamide peroxide bleaching gels showed a similar color change (p < 0.001). Higher enamel hardness decrease and higher enamel roughness were caused by the carbamide peroxide (p < 0.05). The experimental whitening gels did not affect cell viability. Tooth bleaching gels containing bromelain, papain, or ficin have substantial clinical potential to be used in the development of peroxide-free tooth whitening gels.

Efficacy of natural, peroxide-free tooth-bleaching agents: A systematic review, meta-analysis, and technological prospecting.

The aim of this study is to analyze the efficacy of natural bleaching agents and the current technological development in this research field. Two reviewers performed a literature search up to July 2019 in 15 databases. Five laboratory studies and 25 patents were included. Data regarding natural bleaching agent used, application protocol, and the main findings of studies were analyzed. Laboratory studies that evaluated natural bleaching agents' peroxide-free or associated to peroxides and patents related to natural bleaching agents were included. The studies evaluated papain, bromelain, chlorine dioxide, sodium chloride plus vinegar and sodium bicarbonate as peroxide-free agents; and sweet potato extract, lactoperoxidase, and peroxidase associated to peroxide used were included. Twenty-five patents were included; among the most cited are the papain and the chlorine. The addition of non-peroxide agents into peroxide showed improvement in bleaching effect with the incorporation of these non-peroxide agents (p < .05). On the other hand, peroxide-free agents did not show an improvement in bleaching effect (p < .05). The evidence in literature suggested that natural bleaching agents incorporated to peroxide may improve the bleaching. Therefore, the current literature does not support the use of natural agents as dental bleaching.

Repair bond strength of bulk-fill resin composite: Effect of different adhesive protocols.

This study evaluated the effect of different adhesive protocols on the shear bond strength (SBS) of bulk-fill resin composite repaired with bulk-fill or conventional composite. Cylindrical bulk-fill resin composite specimens were prepared and allocated into groups according to the bonding strategy: no treatment, Silane+Scotch Bond Multipurpose (S+SBMP), Tetric N Bond Universal, and Single Bond Universal. Following bonding strategy, bulk-fill or conventional composite buildups were performed. After 24 h of storage in distilled water at 37°C, shear force was applied to the interface using a universal testing machine. The data were analyzed by two-way ANOVA and Tukey test (α=0.05). SBS was influenced by the bonding strategy and the composite used (p<0.001). Irrespective of the composite used, the group S+SBMP yielded the highest SBS values (p<0.001). Repair bond strength of bulk-fill composites can be improved by using a silane coupling agent followed by a hydrophobic resin.

Development and characterization of a novel bulk-fill elastomeric temporary restorative composite.

OBJECTIVES: This study investigated the physical and mechanical properties, antibacterial effect and biocompatibility of novel elastomeric temporary resin-based filling materials (TFMs) containing zinc methacrylate (ZM). MATERIAL AND METHODS: Experimental TFMs were prepared by mixing the zinc methacrylate with monomer, co-monomer, photoinitiator and fillers. A ZM concentration of 0 (control), 0.5% (Z0.5); 1% (Z1), 2% (Z2), or 5% (ZM5) wt% was added to the TFMs. Fermit-N (F) was used for comparison with the experimental material. Microleakage, water sorption/solubility, degree of conversion, depth of cure, ultimate tensile strength, and hardness were determined and compared. A modified direct contact test (DCT) with Enterococcus faecalis and a Streptococcus mutans' biofilm accumulation assay was carried out to evaluate the antimicrobial effect and cytotoxicity of the assay. Statistical comparisons were performed (α=5%). RESULTS: The results showed that the physical and mechanical properties of the experimental TFMs with ZM are comparable with the properties of the commercial reference and some properties were improved, such as lower microleakage and water sorption, and higher ultimate tensile strength values. TFMs with ZM killed E. faecalis only after 1 h. Biofilm development of S. mutans was not affected by the inclusion of ZM in the experimental TFMs. CONCLUSIONS: The present findings suggest that the physical, mechanical and biological properties of the experimental TFMs with ZM are comparable with the properties of the commercial reference. However, some properties were improved, such as lower microleakage and water sorption, and higher ultimate tensile strength values.

A single-center 18-year experience with oral candidiasis in Brazil: a retrospective study of 1,534 cases.

Despite the large number of published studies about oral candidiasis and associated risk factors, reports of large single-center retrospective studies on the prevalence of oral candidiasis, risk factors, and the oral candidiasis types diagnosed more frequently in oral diagnostic reference centers are scarce. The objective of the present study was to retrospectively survey the demographic and clinical profiles of 1,534 patients diagnosed with candidiasis and treated at the Center for Diagnosis of Oral Diseases (CDOD), Pelotas Dental School, Federal University of Pelotas between 1997 and 2014. Using a retrospective, cross-sectional, epidemiological design, data on race, gender, age, systemic diseases, oral candidiasis type and location, symptoms, and harmful habits such as smoking and alcohol consumption were collected. The statistical analysis was performed using STATA version 13.1. Risk factors for chronic atrophic candidiasis (CAC) were evaluated using Poisson regression with robust variance (p ≤ 0.05). The majority of patients with oral candidiasis seen at the CDOD over the 18-year period of analysis were Caucasian women, aged 51-60 years, nonsmokers, and nondrinkers, with no systemic disease, and who wore some form of dental prostheses. CAC was the single most common clinical type of candidiasis detected, and the most frequently affected oral site was the palate. These data from a large single-center in Brazil agree with previous evidence about the clinical and demographic profiles of patients with oral candidiasis.

In situ evaluation of color stability and hardness' decrease of resin-based composites.

OBJECTIVE: To determine the color stability (CS) and hardness' decrease (HD) of two commercial resin-based composites (RBCs), after in situ staining conditions (SC). METHODS: Six disc-shaped specimens (6 × 2 mm) of two RBCs-Filtek Z350 XT (FZX) and IPS Empress Direct (IED)-were randomly distributed into palatal devices. Eight volunteers (aged 20-30 years) participated in this study. The in situ SC consisted of 400 mL consumption (2 × 200 mL/day) of water, orange juice, cola soda, and coffee and 140 mL consumption of red wine, 10 days each. CS was obtained by CIELAB color difference (ΔE*) and HD (in %) by the Knoop method (50 g for 15 s), after curing (baseline) and after the in situ SC. Data were statistically analyzed at α = 0.05 significance level. RESULTS: For both RBCs, the coffee (5.7 ± 0.5 for FZX; 5.9 ± 1.3 for IED) and red wine (6.1 ± 1.1 for FZX; 6.2 ± 1.6 for IED) groups showed the highest ΔE* while water the lowest (1.6 ± 0.6 for FZX; 1.8 ± 0.2 for IED). The highest HD was induced by red wine group for FZX (40.7 ± 5.4) and by cola soda for IED (40.6 ± 3.2) while the water groups (8.3 ± 1.7 for FZX; 7.8 ± 2.1 for IED) presented the lowest values for both RBCs. CONCLUSION: Both RBCs were affected by the in situ SC, but no significant differences for CS and HD were observed between them. Red wine and coffee showed higher discoloration potential. CLINICAL SIGNIFICANCE: This in situ study suggests that color stability and hardness' decrease of resin-based composites were dependent on the type of consumed beverage and materials' composition. Patients with esthetic direct restorations should be aware of the degradative potential of them.