Search

Objectives: To assess the effect of an experimental 58S bioactive glass on dentin permeability (dP) and erosive tooth wear (dentin surface loss - dSL)., Methods: 58S bioactive glass was synthetized using a sol-gel methodology, following by lyophilization and calcination, then mixed with phosphoric acid to obtain a paste (BGP). Forty-eight dentin disks (1 mm-thick) were used for dP, and 48 dentin slabs (3 mm × 3 mm) for dSL, which were assessed at three time intervals: post-EDTA (5 min in 17% EDTA solution); post-treatment (C: distilled water; BGP: experimental bioactive glass paste; NP: Nupro prophylaxis paste; CXT: Clinpro XT varnish); and post-erosive/abrasive cycling. Data were statistically analyzed (α=0.05)., Results: For dP and dSL, Groups did not differ significantly post-EDTA (p>0.05). Post-treatment, all groups showed lower dP than C (p<0.05), without differing significantly among them. For the dSL analysis, Groups C, BGP and NP did not differ significantly, showing lower values than CXT (p<0.05). Post-cycling, C continued to show the highest dP (p<0.05). Specimens from Group CXT had the lowest dP and did not differ from NP (p=0.86) which did not differ from BGP (p=0.193). For C and BGP, dP value was higher post-cycling than post-treatment (p<0.05). For NP and CXT, these experimental times did not differ (p>0.05). Post-cycling, dSL for C, BGP and NP did not differ significantly; values were higher than those for CXT (p<0.05)., Conclusions: BGP reduced dP after application, with a reduced effect after cycling. Nonetheless, it was not able to protect dentin against erosive tooth wear., Clinical Significance: Minimizing dentin hypersensitivity is a challenge in the field of dentistry. The development of alternative products with potential to obliterate dentinal tubules and provide resistance to chemical/mechanical stimuli is, thus, highly desirable. We have proposed a material able to reduce dentin permeability, which has emerged as a promising alternative for this purpose., 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.)

Objective: To evaluate the anti-erosive effect of solutions containing β-tricalcium phosphate (β-TCP) nanoparticles functionalized with fluoride or with fluoride plus stannous on enamel and dentin., Methods: β-TCP nanoparticles were synthesized and characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Sixty enamel and dentin specimens were randomly allocated into the groups (n = 10): Control (water); F (NaF, 225 ppm F - ); F + Sn (NaF + SnCl 2, 800 ppm Sn 2+ ); F+β-TCP (F+40 ppm β-TCP); F + Sn+β-TCP (F + Sn+40 ppm β-TCP); F + Sn+100β-TCP (F + Sn+100 ppm β-TCP). Specimens underwent erosion-remineralization cycling (5 min immersion into 1 % citric acid solution and 60 min exposure to artificial saliva, 4×/day, 5 days). Immersion in the test solutions was performed for 2 min, 2×/day. Surface loss (SL, in μm) was determined by optical profilometry at the end of cycling. Data were analyzed using one way-ANOVA and Tukey's tests (α = 0.05)., Results: XRD confirmed the β-TCP phase. TEM micrographs showed differences between the bare nanoparticle and the β-TCP functionalized with F and Sn. All enamel groups presented lower SL than the control, with F + Sn, F + Sn+β-TCP, and F + Sn+100β-TCP showing the lowest values. For dentin, all the groups had lower SL than the control. F+β-TCP presented the lowest SL, significantly differing from all the other groups., Conclusion: β-TCP nanoparticles functionalized with fluoride showed improved anti-erosive effect compared to the fluoride solution on dentin. There was no significant effect of the β-TCP nanoparticles functionalized with fluoride plus stannous in both substrates., Clinical Relevance: β-TCP nanoparticles are a promising agent to be added to oral health products to improve the protective effect of fluoride against dentin erosion., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Introduction: A biocompatible strategy to promote bacterial eradication within the root canal system after pulpal necrosis of immature permanent teeth is critical to the success of regenerative endodontic procedures. This study sought to synthesize clindamycin-modified triple antibiotic (metronidazole, ciprofloxacin, and clindamycin [CLIN]) polymer (polydioxanone [PDS]) nanofibers and determine in vitro their antimicrobial properties, cell compatibility, and dentin discoloration., Methods: CLIN-only and triple antibiotic CLIN-modified (CLIN-m, minocycline-free) nanofibers were processed via electrospinning. Scanning electron microscopy, Fourier-transform infrared spectroscopy (FTIR), and tensile testing were performed to investigate fiber morphology, antibiotic incorporation, and mechanical strength, respectively. Antimicrobial properties of CLIN-only and CLIN-m nanofibers were assessed against several bacterial species by direct nanofiber/bacteria contact and over time based on aliquot collection up to 21 days. Cytocompatibility was measured against human dental pulp stem cells. Dentin discoloration upon nanofiber exposure was qualitatively recorded over time. The data were statistically analyzed (P < .05)., Results: The mean fiber diameter of CLIN-containing nanofibers ranged between 352 ± 128 nm and 349 ± 128 nm and was significantly smaller than PDS fibers. FTIR analysis confirmed the presence of antibiotics in the nanofibers. Hydrated CLIN-m nanofibers showed similar tensile strength to antibiotic-free (PDS) nanofibers. All CLIN-containing nanofibers and aliquots demonstrated pronounced antimicrobial activity against all bacteria. Antibiotic-containing aliquots led to a slight reduction in dental pulp stem cell viability but were not considered toxic. No visible dentin discoloration upon CLIN-containing nanofiber exposure was observed., Conclusions: Collectively, based on the remarkable antimicrobial effects, cell-friendly, and stain-free properties, our data suggest that CLIN-m triple antibiotic nanofibers might be a viable alternative to minocycline-based antibiotic pastes., (Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Objective: To investigate the effects of Halloysite® aluminosilicate clay nanotubes (HNTs) addition on selected physical, mechanical, and biological properties of experimental adhesive resins., Methods: Experimental dentin adhesive resins were prepared by mixing Bis-GMA, TEGDMA, HEMA (50/25/25wt.%), and photo-initiators. As-received HNTs were then incorporated into the resin mixture at distinct concentrations: 0 (HNT-free, control), 1, 2.5, 5, 7.5, 10, and 20wt.%. The degree of conversion (DC), radiopacity (RP), Knoop hardness (KHN), flexural strength (FS), and cytotoxicity analyses were carried out for each adhesive formulation. The adhesive resin of Adper Scotchbond Multi-Purpose (SBMP) was used as the commercially available reference for both the RP and cytotoxicity tests. Data were statistically analyzed using One-Way ANOVA and Tukey's test (p≤0.05)., Results: All adhesives exhibited similar DC (p=0.1931). The RP of adhesives was improved with the addition of up to 5wt.% of HNTs (p<0.001). Adhesives containing 5-10wt.% of HNTs led to greater KHN when compared to the control (p<0.001). The FS was reduced only when 20wt.% of HNTs was added (p≤0.001). None of the prepared adhesives was cytotoxic., Conclusion: The incorporation of up to 10wt.% of HNTs into the adhesive resins did not jeopardize the tested physical and biological properties., Clinical Significance: When using HNTs as carriers of drugs/bioactive compounds, the amount of the former added into adhesive resin materials should not exceed 10wt.%; otherwise, a significant reduction in physicomechanical properties may be expected., (Copyright © 2015 Elsevier Ltd. All rights reserved.)