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Streptococcus mutans Proteases Degrade Dentinal Collagen. Dent J (Basel) 2022; 10:dj10120223. [PMID: 36547039 PMCID: PMC9776523 DOI: 10.3390/dj10120223] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/21/2022] [Accepted: 11/24/2022] [Indexed: 11/30/2022] Open
Abstract
Here, we explored the role of S. mutans’s whole cell and discrete fractions in the degradation of type I collagen and dentinal collagen. Type I collagen gels and human demineralized dentin slabs (DS) were incubated in media alone or with one of the following: overnight (O/N) or newly inoculated (NEW) cultures of S. mutans UA159; intracellular proteins, supernatant or bacterial membranes of O/N cultures. Media from all groups were analyzed for protease-mediated release of the collagen-specific imino acid hydroxyproline. Images of type I collagen and DS were analyzed, respectively. Type I collagen degradation was highest for the supernatant (p < 0.05) fractions, followed by intracellular components and O/N cultures. Collagen degradation for DS samples was highest for O/N samples, followed by supernatant, and intracellular components (p < 0.05). There was lower detectable degradation for both type I collagen and DS from NEW culture samples (p < 0.05), and there was no type I collagen or DS degradation detected for bacterial membrane samples. Structural changes to type I collagen gel and dentinal collagen were observed, respectively, following incubation with S. mutans cultures (O/N and NEW), intracellular components, and supernatant. This study demonstrates that intracellular and extracellular proteolytic activities from S. mutans enable this cariogenic bacterium to degrade type I and dentinal collagen in a growth-phase dependent manner, potentially contributing to the progression of dental caries.
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Dotta TC, Hayann L, de Padua Andrade Almeida L, Nogueira LFB, Arnez MM, Castelo R, Cassiano AFB, Faria G, Martelli-Tosi M, Bottini M, Ciancaglini P, Catirse ABCEB, Ramos AP. Strontium Carbonate and Strontium-Substituted Calcium Carbonate Nanoparticles Form Protective Deposits on Dentin Surface and Enhance Human Dental Pulp Stem Cells Mineralization. J Funct Biomater 2022; 13:jfb13040250. [PMID: 36412891 PMCID: PMC9680411 DOI: 10.3390/jfb13040250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 11/09/2022] [Accepted: 11/14/2022] [Indexed: 11/19/2022] Open
Abstract
Strontium acetate is applied for dental hypersensitivity treatment; however, the use of strontium carbonates for this purpose has not been described. The use of Sr-carbonate nanoparticles takes advantage of both the benefits of strontium on dentin mineralization and the abrasive properties of carbonates. Here in, we aimed to synthesize strontium carbonate and strontium-substituted calcium carbonate nanoparticles and test them as potential compounds in active dentifrices for treating dental hypersensitivity. For this, SrCO3, Sr0.5Ca0.5CO3, and CaCO3 nanoparticles were precipitated using Na2CO3, SrCl2, and/or CaCl2 as precursors. Their morphology and crystallinity were evaluated by electron microscopy (SEM) and X-ray diffraction, respectively. The nanoparticles were added to a poly (vinyl alcohol) gel and used to brush dentin surfaces isolated from human third molars. Dentin chemical composition before and after brushing was investigated by infrared spectroscopy (FTIR) and X-ray dispersive energy spectroscopy. Dentin tubule morphology, obliteration, and resistance of the coatings to acid attack were investigated by SEM and EDS. The cytotoxicity and ability of the particles to trigger the mineralization of hDPSCs in vitro were studied. Dentin brushed with the nanoparticles was coated by a mineral layer that was also able to penetrate the tubules, while CaCO3 remained as individual particles on the surface. FTIR bands related to carbonate groups were intensified after brushing with either SrCO3 or Sr0.5Ca0.5CO3. The shift of the phosphate-related FTIR band to a lower wavenumber indicated that strontium replaced calcium on the dentin structure after treatment. The coating promoted by SrCO3 or Sr0.5Ca0.5CO3 resisted the acid attack, while calcium and phosphorus were removed from the top of the dentin surface. The nanoparticles were not toxic to hDPSCs and elicited mineralization of the cells, as revealed by increased mineral nodule formation and enhanced expression of COL1, ALP, and RUNX2. Adding Sr0.5Ca0.5CO3 as an active ingredient in dentifrices formulations may be commercially advantageous since this compound combines the well-known abrasive properties of calcium carbonate with the mineralization ability of strontium, while the final cost remains between the cost of CaCO3 and SrCO3. The novel Sr0.5Ca0.5CO3 nanoparticles might emerge as an alternative for the treatment of dental hypersensitivity.
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Affiliation(s)
- Tatiane Cristina Dotta
- Department of Dental Materials and Prosthodontics, Ribeirão Preto School of Dentistry, University of São Paulo, Ribeirão Preto 14040-904, Brazil
| | - Larwsk Hayann
- Department of Chemistry, Ribeirão Preto Faculty of Philosophy, Sciences and Letters at Ribeirão Preto, University of São Paulo, Ribeirão Preto 14040-901, Brazil
| | - Leonardo de Padua Andrade Almeida
- Department of Dental Materials and Prosthodontics, Ribeirão Preto School of Dentistry, University of São Paulo, Ribeirão Preto 14040-904, Brazil
| | - Lucas Fabrício B. Nogueira
- Department of Chemistry, Ribeirão Preto Faculty of Philosophy, Sciences and Letters at Ribeirão Preto, University of São Paulo, Ribeirão Preto 14040-901, Brazil
| | - Mayara M. Arnez
- Department of Dental Materials and Prosthodontics, Ribeirão Preto School of Dentistry, University of São Paulo, Ribeirão Preto 14040-904, Brazil
| | - Raisa Castelo
- Department of Dental Materials and Prosthodontics, Ribeirão Preto School of Dentistry, University of São Paulo, Ribeirão Preto 14040-904, Brazil
| | - Ana Flávia B. Cassiano
- Department of Restorative Dentistry, School of Dentistry at Araraquara, Sao Paulo State University (UNESP), Araraquara 14801-385, Brazil
| | - Gisele Faria
- Department of Restorative Dentistry, School of Dentistry at Araraquara, Sao Paulo State University (UNESP), Araraquara 14801-385, Brazil
| | - Milena Martelli-Tosi
- Department of Chemistry, Ribeirão Preto Faculty of Philosophy, Sciences and Letters at Ribeirão Preto, University of São Paulo, Ribeirão Preto 14040-901, Brazil
- Department of Food Engineering, Faculty of Animal Science and Food Engineering, University of São Paulo, Pirassununga 13645-900, Brazil
| | - Massimo Bottini
- Department of Experimental Medicine, University of Rome Tor Vergata, 00133 Rome, Italy
| | - Pietro Ciancaglini
- Department of Chemistry, Ribeirão Preto Faculty of Philosophy, Sciences and Letters at Ribeirão Preto, University of São Paulo, Ribeirão Preto 14040-901, Brazil
| | - Alma B. C. E. B. Catirse
- Department of Dental Materials and Prosthodontics, Ribeirão Preto School of Dentistry, University of São Paulo, Ribeirão Preto 14040-904, Brazil
| | - Ana Paula Ramos
- Department of Chemistry, Ribeirão Preto Faculty of Philosophy, Sciences and Letters at Ribeirão Preto, University of São Paulo, Ribeirão Preto 14040-901, Brazil
- Correspondence:
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H S Delgado A, Belmar Da Costa M, Polido MC, Mano Azul A, Sauro S. Collagen-depletion strategies in dentin as alternatives to the hybrid layer concept and their effect on bond strength: a systematic review. Sci Rep 2022; 12:13028. [PMID: 35906302 PMCID: PMC9338246 DOI: 10.1038/s41598-022-17371-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Accepted: 07/25/2022] [Indexed: 01/01/2023] Open
Abstract
Strategies aiming to improve the longevity of resin-dentin adhesive interface developed so far have only been able to retard the problem. Different approaches are thus needed. The objective of this review was to determine whether the use of collagen-depletion strategies after acid-etching procedures may improve the bond strength of resin-based materials to dentin. A systematic review was planned following 2021 PRISMA statement guidelines, with a search strategy performed in five electronic databases: PubMed/Medline, Scopus, EMBASE, SciELO and IADR Abstract Archive (last search: 17/01/2022). Inclusion criteria encompassed studies which evaluated a collagen-depletion strategy in acid-etched human dentin and tensile/shear bond strength tests. Risk of bias assessment was carried out by two reviewers, working independently on an adapted five-domain risk of bias (RoB) checklist for laboratory studies. Results were synthesized qualitatively, as a meta-analysis was not possible due to limited number of studies and their RoB. A total of eight studies were eligible for inclusion in the systematic review after inclusion/exclusion criteria application. Out of these, two evaluated the effect of using NaOCl followed by an antioxidant, and the remaining six evaluated different enzymatic treatments (bromelain, chondroitinase ABC, papain, and trypsin). None of the studies reported a decrease of bond strength when a collagen-depletion strategy was used, in comparison to traditional hybrid layers (control). All enzymatic treatment studies which respected the inclusion criteria improved the bond strength to dentin. Some specific collagen-depletion strategies seem to play a favorable role in improving immediate bond strengths to dentin. Further research with sound methodology is required to consolidate these findings, since limitations in RoB and a low number of studies were found. The assessment of further proteolytic agents and long-term outcomes is also required.
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Affiliation(s)
- António H S Delgado
- Centro de Investigação Interdisciplinar Egas Moniz (CiiEM), Instituto Universitário Egas Moniz (IUEM), Campus Universitário, Quinta da Granja, Monte de Caparica, 2829-511, Almada, Portugal. .,Division of Biomaterials and Tissue Engineering, UCL Eastman Dental Institute, University College London, London, UK.
| | - Madalena Belmar Da Costa
- Centro de Investigação Interdisciplinar Egas Moniz (CiiEM), Instituto Universitário Egas Moniz (IUEM), Campus Universitário, Quinta da Granja, Monte de Caparica, 2829-511, Almada, Portugal
| | - Mário Cruz Polido
- Centro de Investigação Interdisciplinar Egas Moniz (CiiEM), Instituto Universitário Egas Moniz (IUEM), Campus Universitário, Quinta da Granja, Monte de Caparica, 2829-511, Almada, Portugal
| | - Ana Mano Azul
- Centro de Investigação Interdisciplinar Egas Moniz (CiiEM), Instituto Universitário Egas Moniz (IUEM), Campus Universitário, Quinta da Granja, Monte de Caparica, 2829-511, Almada, Portugal
| | - Salvatore Sauro
- Dental Biomaterials and Minimally Invasive Dentistry, Department of Dentistry, Cardenal Herrera-CEU University, CEU Universities, Valencia, Spain
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Favetti M, Schroeder T, Montagner AF, Moraes RR, Pereira-Cenci T, Cenci MS. NaOCl Application after Acid Etching and Retention of Cervical Restorations: A 3-Year Randomized Clinical Trial. Oper Dent 2022; 47:268-278. [PMID: 35584331 DOI: 10.2341/20-166-c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/25/2021] [Indexed: 11/23/2022]
Abstract
This study evaluated the retention of composite resin restorations in noncarious cervical lesions (NCCLs) performed with or without pretreatment with 10% NaOCl solution (deproteinization). A randomized, controlled, split-mouth, doubleblinded trial was carried out. Thirty patients with at least two NCCLs were included in the study. The NCCLs were randomly allocated into two treatment groups: control (acid etching with 37% phosphoric acid + placebo solution + Adper Single Bond 2/3M Oral Care + Filtek Z350/3M Oral Care) or experimental group (acid etching with 37% phosphoric acid + 10% NaOCl solution + Adper Single Bond 2 + Filtek Z350). A calibrated examiner evaluated the restorations at baseline (1 week) and recalls (6, 12, 24, and 36 months) using the FDI criteria. The primary outcome evaluated was retention of the restorations. Data were analyzed by the Kaplan-Meier method and the log-rank test (α=0.05). After 3 years, 64 restorations were evaluated in 23 patients. The annual failure rate was 9% for the control group and 17.8% for the experimental group (deproteinization technique). Considering the failures and their distribution among the characteristics of the patients and NCCLs, no statistically significant differences were observed for the control and experimental treatment groups (p=0.077) or the number of teeth in the mouth (p=0.320). Restorations in the mandible (p=0.039) and premolars (p=0.013) showed significantly lower clinical survival rates. The deproteinization pretreatment with a 10% NaOCl solution did not promote additional retention of restorations in NCCLs. (clinicaltrials. gov: NCT03086720).
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Affiliation(s)
- M Favetti
- Morgana Favetti, DDS, MS, PhD student, Graduate Program in Dentistry, School of Dentistry, Federal University of Pelotas, Brazil
| | - T Schroeder
- Thaiane Schroeder, DDS, Graduate Program in Dentistry, School of Dentistry, Federal University of Pelotas, Brazil
| | - A F Montagner
- *Anelise Fernandes Montagner, DDS, MS, PhD, Graduate Program in Dentistry, School of Dentistry, Federal University of Pelotas, Brazil
| | - R R Moraes
- Rafael Ratto Moraes, DDS, MS, PhD, Graduate Program in Dentistry, School of Dentistry, Federal University of Pelotas, Brazil
| | - T Pereira-Cenci
- Tatiana Pereira-Cenci, DDS, MS, PhD, associate professor, Graduate Program in Dentistry, School of Dentistry, Federal University of Pelotas, Brazil
| | - M S Cenci
- Maximiliano Sergio Cenci, DDS, MS, PhD, associate professor, Graduate Program in Dentistry, School of Dentistry, Federal University of Pelotas, Brazil
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Camilleri J, Borg J, Damidot D, Salvadori E, Pilecki P, Zaslansky P, Darvell BW. Colour and chemical stability of bismuth oxide in dental materials with solutions used in routine clinical practice. PLoS One 2020; 15:e0240634. [PMID: 33176336 PMCID: PMC7657490 DOI: 10.1371/journal.pone.0240634] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Accepted: 09/29/2020] [Indexed: 11/19/2022] Open
Abstract
Bismuth(III) oxide is included as a radio-opacifier in dental materials, including hydraulic silicate cements, the material of choice for several endodontic procedures. It has been implicated in tooth discoloration after contact with endodontic irrigants, in particular NaOCl solution, To date, there has been no work on the chemistry: all reports have been of clinical findings only. The purpose now was to report the reactions leading to colour change from Bi2O3 in contact with solutions used in routine endodontic practice. Ten-gram portions of Bi2O3 were immersed in either water, NaOH, NaCl, NaOCl or HCl solution, either in the dark or exposed to visible light, and samples retrieved at 1, 4, 12 and 24 weeks. After washing, these were exposed to either added CO2 or not, for 1 week while drying, and under the same dark or light conditions. Changes in appearance were monitored by photography and colour measurement, and chemically by X-ray diffraction and Fourier-transform infrared spectroscopy. 24-week material was studied using electron paramagnetic resonance and Raman spectroscopy; NaOCl-treated material was also examined by scanning electron microscopy. With water, NaCl and NaOH, bismuth subcarbonate was formed. With or without added carbon dioxide, discoloration occurred from pale yellow to light brown when exposed to light, and to a lesser extent in the dark, intensifying with time. In contrast, exposure to NaOCl rapidly formed a dark brown-black sodium bismuthate. With HCl, white BiOCl was formed. Bi2O3 is not at all inert in this context as is commonly believed, denying its principle of use. Previously unreported solution-mediated reaction occurs readily even in water and NaCl solution, forming new compounds that discolour. In contact with NaOCl sodium bismuthate is formed; severe darkening occurs rapidly. The reactivity is such that Bi2O3 is not indicated for dental materials and should be withdrawn from use.
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Affiliation(s)
- Josette Camilleri
- School of Dentistry, University of Birmingham, Birmingham, United Kingdom
| | - Joseph Borg
- Systems Engineer, Triq L-Uqija Ta L-Ibrag, Is-Swieqi, Malta
| | - Denis Damidot
- Department of Civil and Structural Engineering, Faculty of Civil Engineering, Ecole de Mines, LGCgE-GCE, Douai, France
| | | | - Peter Pilecki
- Imaging and Microscopy, King’s College London, London, United Kingdom
| | - Paul Zaslansky
- Department for Operative and Preventive Dentistry, Centrum für Zahn-, Mund- und Kieferheilkunde, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Brian W. Darvell
- School of Dentistry, University of Birmingham, Birmingham, United Kingdom
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Nima G, Cavalli V, Bacelar‐Sá R, Ambrosano GMB, Giannini M. Effects of sodium hypochlorite as dentin deproteinizing agent and aging media on bond strength of two conventional adhesives. Microsc Res Tech 2019; 83:186-195. [DOI: 10.1002/jemt.23401] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 10/02/2019] [Accepted: 10/17/2019] [Indexed: 11/08/2022]
Affiliation(s)
- Gabriel Nima
- Department of Restorative DentistryPiracicaba Dental School, State University of Campinas Piracicaba São Paulo Brazil
| | - Vanessa Cavalli
- Department of Restorative DentistryPiracicaba Dental School, State University of Campinas Piracicaba São Paulo Brazil
| | - Renata Bacelar‐Sá
- Department of Restorative DentistryPiracicaba Dental School, State University of Campinas Piracicaba São Paulo Brazil
| | - Gláucia M. B. Ambrosano
- Department of Social DentistryPiracicaba Dental School, State University of Campinas Piracicaba São Paulo Brazil
| | - Marcelo Giannini
- Department of Restorative DentistryPiracicaba Dental School, State University of Campinas Piracicaba São Paulo Brazil
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Effect and Stability of Poly(Amido Amine)-Induced Biomineralization on Dentinal Tubule Occlusion. MATERIALS 2017; 10:ma10040384. [PMID: 28772744 PMCID: PMC5506945 DOI: 10.3390/ma10040384] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 03/26/2017] [Accepted: 03/29/2017] [Indexed: 02/05/2023]
Abstract
In recent years, scientists have developed various biomaterials to remineralize human teeth to treat dentine hypersensitivity. Poly(amido amine) (PAMAM) dendrimers have become a research focus in this field. It has been demonstrated that PAMAM is able to create precipitates both on the surface of and within the dentinal tubules, however, there is little information about its effect on reducing dentine permeability in vitro. This study aimed to evaluate the in vitro effectiveness and stability of the fourth generation amine-terminated PAMAM on dentinal tubule occlusion, especially on dentine permeability. Sodium fluoride (NaF), which has been widely used as a desensitizing agent, is regarded as positive control. Demineralized sensitive dentine samples were coated with PAMAM or sodium fluoride solutions and soaked in artificial saliva (AS) at 37 °C for different periods. Four weeks later, samples in each group were then equally split into two subgroups for testing using a brushing challenge and an acid challenge. Dentine permeability of each specimen was measured before and after each challenge using a fluid filtration system. Dentine morphology and surface deposits were characterized by scanning electron microscope (SEM) and analyzed with Image-Pro Plus software. Data were evaluated through multifactorial ANOVA with repeated measures and pair-wise comparisons at a level of 5%. The results showed that PAMAM and NaF significantly reduced dentine permeability to 25.1% and 20.7%. Both of them created precipitates on dentine surfaces after AS immersion for 28 days. PAMAM-induced biomineralization not only on dentine surfaces, but also deeper in dentinal tubules, significantly reduced dentine permeability. Moreover, PAMAM-induced biomineralization elicited excellent stable occlusion effects after acid challenge. In conclusion, PAMAM demonstrated a strong ability to resist acid and showed great potential to be used in the treatment of dentine hypersensitivity in future.
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Bahrololoomi Z, Dadkhah A, Alemrajabi M. The Effect of Er:YAG Laser Irradiation and Different Concentrations of Sodium Hypochlorite on Shear Bond Strength of Composite to Primary Teeth's Dentin. J Lasers Med Sci 2017; 8:29-35. [PMID: 28912941 DOI: 10.15171/jlms.2017.06] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Introduction: The aim of this study was to evaluate the effect of various concentrations of NaOCl on shear bond strength of composite resin to dentin of primary teeth, prepared with laser and bur. Methods: In this in vitro study, 48 primary molars were sectioned at mesiodistal direction and were randomly divided into 6 groups; G1: bur, G2: bur + NaOCl 2.5%, G3: bur + NaOCl 5.25%, G4: laser, G5: laser + NaOCl 2.5%, G6: laser + NaOCl 5.25%. One-Step Plus adhesive was applied after phosphoric acid gel and NaOCl over the dentin surfaces for all groups, and composite resin cylinders were bonded to the samples. After thermocycling, shear bond strengths of composite resin to dentin were measured and statistical analyses were done by means of t test and analysis of variance (ANOVA). Results: The mean shear bond strength showed no significant difference between the groups prepared with bur (13.82 ± 3.49) and laser (14.18 ± 3.65) (P > 0.05). The mean difference of shear bond strength between three groups G1, G2 and G3 and between G4, G5 and G6 were not statistically significant (P > 0.05). Scanning electron microscopy (SEM) figures showed an irregular surface in laser groups and fairly complete removal of smear layer from the orifices of the dentinal tubules, in the group in which NaOCl was used. Conclusion: The application of different concentrations of NaOCl does not significantly improve the bond strength in dentin surfaces prepared with laser or bur.
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Affiliation(s)
- Zahra Bahrololoomi
- Department of Pediatric Dentistry, Faculty of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Azam Dadkhah
- Department of Pediatric, School of Dentistry, Qom University of Medical Sciences, Qom, Iran
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Furuse AY, Cunha LF, Baratto SP, Leonardi DP, Haragushiku GA, Gonzaga CC. Bond strength of fiber-reinforced posts to deproteinized root canal dentin. J Contemp Dent Pract 2014; 15:581-6. [PMID: 25707830 DOI: 10.5005/jp-journals-10024-1583] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
AIM This study evaluated the push-out bond strength of cemented fiber posts after deproteinization of root canal dentin walls with NaOCl. The effect of the application of an antioxidant solution (sodium ascorbate) was also evaluated. MATERIALS AND METHODS A three-step etch-and-rinse (Scotch-bond - 3M Espe) and a one-step self-etching adhesive (Xeno III - Dentsply Caulk) were evaluated. Thirty bovine incisor roots were divided into 3 groups: a. Irrigation with physiologic solution (control). b. Deproteinization with 10 minutes irrigation of 5% NaOCl. c. Deproteinization with NaOCl followed by 10 minutes irrigation with 10% ascorbic acid. Fiber posts were cemented with a dual-cured cement (Rely X ARC - 3M ESPE). The push-out bond strength was evaluated after 24 hours of storage in distilled water. The data were analyzed with three-way ANOVA, one-way ANOVA and Tukey's test (α = 0.05). RESULTS There were significant differences between groups (p < 0.05). The bond strength of Scotchbond was not influenced by the deproteinization. Xeno III showed a decrease in bond strength when deproteinized with 5% NaOCl (p < 0.05). For Xeno III, the subsequent irrigation with ascorbic acid was able to reverse the effect of the deproteinization. Considering the radicular thirds, the bond strength varied in the sequence-apical < middle < coronal. CONCLUSION Only the all-in-one adhesive was influenced by the deproteinization. Considering the respective control groups, both systems showed similar bond strength results. CLINICAL SIGNIFICANCE The decreased bond strength of the self-etching adhesive following deproteinization seams to be related to the oxidant effect of the NaOCl solution and the subsequent irrigation with ascorbic acid was able to reverse the effect of the deproteinization.
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Affiliation(s)
- Adilson Yoshio Furuse
- Assistant Professor, Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of Sao Paulo Bauru, Sao Paulo, Brazil, e-mail:
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Zheng X, Hu J, Chen Y, Zhu Y, Chen H. AFM study of the effects of collagenase and its inhibitors on dentine collagen fibrils. J Dent 2011; 40:163-71. [PMID: 22198196 DOI: 10.1016/j.jdent.2011.12.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Revised: 12/07/2011] [Accepted: 12/08/2011] [Indexed: 01/23/2023] Open
Abstract
OBJECTIVE This study evaluated the effects of exogenous collagenase and two collagenase inhibitors on the variation in microstructure of human collagen fibrils. METHODS Dentine specimens which were sectioned from 6 freshly extracted human caries-free third molars were wet polished. Each specimen was divided into 4 parts which were treated as experimental groups (group 1, group 2, group 3) and the control group, respectively. All the specimens were etched and further treated with NaClOaq. Subsequently, the topography of each specimen was observed using atomic force microscopy (AFM) in tapping mode in air. Group 1 was then treated with a solution of collagenase II. Group 2 was treated with a solution of collagenase II and chlorhexidine (saturated solution). Group 3 was treated with a solution of collagenase II and captopril (0.3%). The control group was treated with a buffer solution. After 3h and 6h of treatment, the topography of the collagen fibrils was measured with AFM in air, respectively. RESULTS AFM images of the dentine collagen fibrils were obtained after treatment with NaOClaq. Following further treatment with collagenase II, the topography of the collagen fibrils changed. Most reticular collagen fibrils disappeared after 6h. After treatment with collagenase II in the presence of chlorhexidine or captopril for 3h and 6h, the morphology of the collagen fibres was not changed obviously. CONCLUSIONS Exogenous collagenase II effectively degraded human dentine collagen fibrils, and its collagenolytic activity was inhibited by the exogenous collagenase inhibitors, chlorhexidine and captopril.
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Affiliation(s)
- Xinyu Zheng
- Department of Conservative Dentistry and Periodontic, Affiliated Hospital of Stomatology, Medical College, Zhejiang University, Hangzhou 310006, China
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Cecchin D, Almeida JFA, Gomes BPFA, Zaia AA, Ferraz CCR. Deproteinization technique stabilizes the adhesion of the fiberglass post relined with resin composite to root canal. J Biomed Mater Res B Appl Biomater 2011; 100:577-83. [PMID: 22102546 DOI: 10.1002/jbm.b.31946] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Revised: 06/25/2011] [Accepted: 07/07/2011] [Indexed: 12/30/2022]
Abstract
To evaluate the effects of pretreatment of root dentin by 5.25% sodium hypochlorite (NaOCl) alone, associated with 2% chlorhexidine in gel base (CHX) and/or ethanol (EtOH), and the air-drying technique (Air) on the bond strength and adhesive durability of fiberglass post relined with resin composite to root dentin. A total of 100 bovine incisor roots were divided into 10 groups: G1 (control), irrigation with physiologic solution; G2, Air; G3, NaOCl; G4, NaOCl + Air; G5, NaOCl + EtOH; G6, NaOCl + EtOH + Air; G7, NaOCl + CHX; G8, NaOCl + CHX + Air; G9, NaOCl + CHX + EtOH; G10, NaOCl + CHX + EtOH + Air. Fiberglass post relined with resin composite was cemented and each group was randomly divided into two subgroups: 24 h of water storage and 12 months of water storage. The push-out test was performed and bond strength values were analyzed by ANOVA and Tukey's test. The use of NaOCl alone or associated with CHX had the highest values of bond strength with or without Air in the immediate and stored groups, being statistically similar to the immediate control group (p > 0.05). The groups using EtOH or Air alone had lower bond strength in the immediate and stored groups (p < 0.05). A significant decrease with the time of the bond strength in the control group was observed after 12 months of storage (p > 0.05). The use of NaOCl or NaOCl associated with CHX preserved the bond strength immediate and for 12 months. The air-drying technique and the other associations decreased the immediate bond strength values.
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Affiliation(s)
- Doglas Cecchin
- Endodontics Division, Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Piracicaba, Brazil.
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Wang Z, Sa Y, Sauro S, Chen H, Xing W, Ma X, Jiang T, Wang Y. Effect of desensitising toothpastes on dentinal tubule occlusion: a dentine permeability measurement and SEM in vitro study. J Dent 2010; 38:400-10. [PMID: 20097250 DOI: 10.1016/j.jdent.2010.01.007] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2009] [Revised: 01/10/2010] [Accepted: 01/15/2010] [Indexed: 11/26/2022] Open
Abstract
OBJECTIVES The purpose of this study was to evaluate the in vitro effectiveness of a new bioglass-containing and two commercial desensitising toothpastes on dentinal tubule occlusion after citric acid challenge or artificial saliva (AS) immersion. METHODS One hundred dentin discs from human third molars were used. Specimens were randomly divided into five groups (n=20), Group 1: EDTA-treated dentin; Group 2: brushing with distilled water; Group 3: brushing with Novamin; Group 4: brushing with Sensodyne Freshmint; Group 5: brushing with Colgate Sensitive. In each group, samples were then equally split into two subgroups (n=10) to test two post-treatments: 6% citric acid challenge or 24h immersion in artificial saliva. Dentine permeability of each specimen was measured before and after each treatment using a hydrostatic device working at 20cm H(2)O pressure. Data were analysed by two-way repeated measures ANOVA to determine if there were any significant differences within or between groups. Dentine morphology and surface deposits were observed by SEM. RESULTS All three desensitising toothpastes significantly reduced dentine permeability and created precipitates on the treated dentine surfaces. Moreover, the reductions in dentine permeability showed partial recovery after a citric acid and artificial saliva immersion. Sensodyne showed significant resistant to acid attack and Novamin exhibited the lowest permeability after artificial saliva immersion for 24h. CONCLUSIONS The application of the three toothpastes resulted in effective dentinal tubule occlusion. However, the new bioglass-containing toothpaste (Novamin) represented excellent occlusion effects after brushing treatment and AS immersion, while Sensodyne demonstrated more reduction in permeability when citric acid challenged.
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Affiliation(s)
- Zhejun Wang
- Key Laboratory for Oral Biomedical Engineering, Ministry of Education, School and Hospital of Stomatology, Wuhan University, 237 Luoyu Road, Wuhan 430079, PR China
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Sauro S, Mannocci F, Toledano M, Osorio R, Pashley DH, Watson TF. EDTA or H3PO4/NaOCl dentine treatments may increase hybrid layers' resistance to degradation: a microtensile bond strength and confocal-micropermeability study. J Dent 2009; 37:279-88. [PMID: 19155116 DOI: 10.1016/j.jdent.2008.12.002] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2008] [Revised: 12/03/2008] [Accepted: 12/09/2008] [Indexed: 11/25/2022] Open
Abstract
OBJECTIVES The aim of this study was to reduce hybrid layer degradation created with simplified dentine adhesives by using two different methods to condition the dentine surface. METHODS A smear-layer was created on flat dentine surfaces from extracted human third molars with a 180-grit/SiC-paper. Dentine specimens were conditioned before bonding with the following procedures: 37% H(3)PO(4); H(3)PO(4)/0.5% NaOCl; 0.1M EDTA; 0.1M EDTA/0.5% NaOCl. Two etch-and-rinse adhesives: (Scotchbond 1XT or Optibond Solo Plus) were applied and light-cured. Composite build-ups were constructed. The bonded teeth were sectioned into beams, stored in distilled water (24h) or 12% NaOCl solution (90 min) and finally tested for microtensile bond strengths (microTBS). Additional dentine surfaces were conditioned and bonded as previously described. They were prepared for a pulpal-micropermeability confocal microscopy study and finally observed using confocal microscopy. RESULTS microTBS results revealed that both adhesives gave high bond strengths to acid-etched dentine before, but not after a 12% NaOCl challenge. Bonds made to acid-etched or EDTA-treated dentine plus dilute NaOCl, gave high microTBS that resisted 12% NaOCl treatment, as did EDTA-treated dentine alone. A confocal micropermeability investigation showed very high micropermeability within interfaces of the H(3)PO(4), etched specimens. The lowest micropermeability was observed in H(3)PO(4)+0.5% NaOCl and 0.1M EDTA groups. CONCLUSIONS The use of dilute NaOCl (0.5%) after acid-etching, or the conditioning of dentine smear layers with 0.1M EDTA (pH 7.4) produced less porous resin-dentine interfaces. These dentine-conditioning procedures improve the resistance of the resin-dentine bond sites to chemical degradation (12% NaOCl) and may result in more durable resin-dentine bonds.
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Affiliation(s)
- Salvatore Sauro
- Dental Biomaterials Science, Biomimetics & Biophotonics, King's College London Dental Institute at Guy's, King's College and St Thomas's Hospitals, Floor 17 Guy's Hospital, London, UK.
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