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OBJECTIVES: To evaluate the effects of the phosphoric acid (PA) etching, self-etching technique (SE) and blasting with Al2O3 particles (BL) on the bonding of a dental adhesive to intact (INT) or abraded (ABR) enamel. METHODS: Enamel surfaces were treated as follows: 1- ABR-PA: INT was abraded with SiC paper and etched with PA (20 s) before Clearfil Universal Bond Quick adhesive application; 2- ABR-SE: ABR was SiC and adhesive applied in SE mode; 3- INT-PA: INT was etched with PA and adhesive applied; 4- INT-SE: the adhesive (SE mode) was applied to INT; 5- INT-BL: INT was BL and the adhesive was applied (SE mode), and 6- INT-BA: INT was BL, etched with PA and adhesive applied (SE mode). The enamel surface treated was examined with scanning electron microscopy (SEM) (n = 3) and Al2O3 particles were characterized using SEM and EDX. The enamel bond strength was measured by microtensile test (24 h and 1 year) (n = 8) and the morphology of enamel-adhesive interfaces were analyzed by SEM (n = 3). Bond strength data were analyzed by two-way ANOVA and Tukey's test (α = 0.05). RESULTS: Al2O3 particles had an irregular shape, their length varied (50-20 µm) and the perimeter mean was 38.8 µm. The enamel morphology significantly influenced the enamel bond strength. ABR-PA, INT-BL, and INT-BA provided greater and stable enamel-dentin interaction and bond strength. SIGNIFICANCE: The enamel morphology significantly influenced the enamel bond strength. Using the adhesive in etch-and-rinse mode, enamel must be abraded before etching and must be Al2O3-blasted when used in SE mode.
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To evaluate the effect of adhesive coats application on the enamel microtensile bond strength (µTBS) of universal adhesives, morphological etching pattern and their chemical interaction with hydroxyapatite (HA). Two universal adhesives were investigated: Scotchbond Universal (SBU, 3 M) and Prime&Bond Universal (PBU, Dentsply). The adhesives were applied in self-etching mode on bovine enamel (n = 8) in one (1L), two (2L) or three coats (3L) and light-cured as per manufacturers' instructions. As controls adhesives were applied to etched enamel (H3PO4-37% phosphoric acid). Bonded specimens were cut into sticks that were stored in deionized water for 24 h or 6 months prior to µTBS testing. Two-way ANOVA and Tukey's test were used for statistical analysis of bond strength with α = 5%. For morphological SEM analysis, enamel surfaces were treated as aforementioned and immediately rinsed with acetone. The intensity of monomer-calcium salt formation from each treatment was measured via infrared spectroscopy (ATR-FTIR). All treatments presented no significant reduction on µTBS after aging (p > 0.05). However, SBU attained highest µTBS when applied in 3L. PBU showed higher µTBS when applied to H3PO4 etched enamel than 1L or 2L. Etching pattern was enhanced by 3L application, particularly with PBU. Chemical interaction was notably higher for SBU than PBU, with no relevant differences with more layers or prior H3PO4-etching. The application of three adhesive coats of universal adhesives in self-etch mode using may enhance the bonding performance and etching pattern to enamel, surpassing the H3PO4-etched enamel bond for SBU. The chemical interaction with calcium from enamel is not affected by number of coats or prior phosphoric acid etching.
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Objective: To evaluate the enamel bonding ability and orthodontic adhesive resin degree of conversion using the experimental bracket design. Material and Methods. Thirteen bovine teeth were used in the study. The experimental bracket was modified with a translucent region in the center of its body. After enamel etching, Orthocem orthodontic adhesive (FGM, Joinville, Brazil) was applied on the bracket base for bonding. The groups were divided as follows (n = 10 per group): (1) control (CB) with standard brackets and (2) spot bracket (SB) with experimental brackets featuring a 0.8 mm translucent region at the center using carbide bur. Shear bond strength (SBS) was evaluated after 24 hours in a universal testing machine and adhesive remnant index (ARI). The degree of conversion (DC) was analyzed using Raman spectroscopy (n = 3 per group). Data were then analyzed using Student's t-test and Mann-Whitney statistical methods. Results: The SB group exhibited a higher mean SBS (10.33 MPa) compared to the CB Group (8.77 MPa). However, there was no statistical difference between the groups (p = 0.376). Both SB and CB groups had a mean ARI score of 1. Raman analysis revealed a higher degree of conversion in the SB group (49.3%) compared to the CB group (25.9%). Conclusions: The experimental support showed a higher degree of adhesive conversion, although there was no significant increase in bond strength.
Subject(s)
Composite Resins , Dental Bonding , Dental Enamel , Orthodontic Brackets , Polymerization , Shear Strength , Animals , Cattle , Dental Bonding/methods , Dental Enamel/chemistry , Composite Resins/chemistry , Materials Testing , Dental Cements/chemistry , Resin Cements/chemistryABSTRACT
OBJECTIVE: Remineralising composites with antibacterial properties may seal the cavity and prevent secondary caries. This study aimed at developing experimental flowable composites containing different concentrations of fluoride-doped calcium phosphate fillers and evaluating their remineralising and antibacterial properties. METHODS: Experimental resin-based composites containing different concentrations (0-20 %) of fluoride-doped calcium phosphate fillers (VS10/VS20) were formulated. The release of calcium (Ca), phosphate (PO) and fluoride (F) ions was assessed for 30 days. Remineralisation properties were evaluated through ATR-FTIR and SEM/EDX after storage in simulated body fluid (SBF). The metabolic activity and viability of Streptococcus gordonii was also evaluated through ATP, CFU and live/dead confocal microscopy. The evaluation of specific monomer elution from the experimental composites was conducted using high-performance liquid chromatography (HPLC). RESULTS: The composites containing VS10 showed the highest release of Ca, those containing VS20 released more F over time (p < 0.05), while there was no significant difference in terms of PO ions release between the groups (p > 0.05). A quick 7-day mineral precipitation was observed in the tested composites containing VS10 or VS20 at 10 %; these materials also showed the greatest antibacterial activity (p < 0.05). Moreover, the tested composites containing VS10 presented the lowest elution of monomers (p < 0.05). CONCLUSIONS: Innovative composites were developed with low monomers elution, evident antibacterial activity against S. gordonii and important remineralisation properties due to specific ions release. CLINICAL SIGNIFICANCE: Novel composites containing fluoride-doped calcium phosphates may be promising to modulate bacteria growth, promote remineralisation and reduce the risk of cytotoxicity related to monomers' elution.
Subject(s)
Fluorides , Phosphates , Phosphates/pharmacology , Phosphates/chemistry , Fluorides/pharmacology , Fluorides/chemistry , Materials Testing , Composite Resins/pharmacology , Composite Resins/chemistry , Calcium Phosphates/pharmacology , Calcium Phosphates/chemistry , Calcium Fluoride , Anti-Bacterial Agents/pharmacologyABSTRACT
BACKGROUND: Alternatively to conventional treatments, chemo-mechanical caries removal agents can be used. A modality of treatment that has been increasing in dentistry is antimicrobial photodynamic therapy (aPDT). Bixa orellana is being researched for application in aPDT. This protocol aims to determine the effectiveness of aPDT with Bixa orellana extract in deep caries lesions. METHODS: A total of 160 teeth with deep occlusal dental caries will be selected and divided into 4 groups: G1 - control group (Caries removal with a low-speed drill); G2 - Partial Caries Removal with Papacarie™ (Fórmula e Ação, São Paulo, SP, Brazil); G3 - Partial Caries Removal with Papacarie™ and application Bixa orellana extract (20%) (Fórmula e Ação, São Paulo, SP, Brazil); G4 - Partial Caries Removal with Papacarie™ and application Bixa orellana extract (20%) with LED (Valo Cordless Ultradent®, South Jordan, UT, USA) (aPDT). After treatment, all the teeth will be restored with glass ionomer cement and followed up clinically and radiographically, with evaluations at immediately, 1 week, and 1, 3, 6, and 12 months. Dentin samples before and after treatment will be analyzed microbiologically. The efficacy of treatments will be assessed with microbiological (colony-forming units, before and after carious tissue removal), radiographic (integrity of the periapical area and eventual changes in the radiolucent zones), and clinical examinations (retention of the restorative material in the cavity and occurrence of secondary caries), as well as with the time required for the procedures and the need for anesthesia during the procedures. In case data distribution is normal, analysis of variance (ANOVA) will be used for both the dependent and independent variables. In case the data distribution is not normal, the Friedman test will be used for the dependent variables. For independent variables, the Kruskal-Wallis test will be used. DISCUSSION: Procedures using aPDT have been developed for the treatment of dental caries, but there are few controlled clinical trials in the literature confirming its efficacy. TRIAL REGISTRATION: This protocol is registered at ClinicalTrials.gov under the number NCT05236205 and it was first posted on 01/21/2022 and last updated on 05/10/2022.
Subject(s)
Anti-Infective Agents , Dental Caries , Photochemotherapy , Humans , Dental Caries Susceptibility , Brazil , Bixaceae , Plant Extracts , Randomized Controlled Trials as TopicABSTRACT
The aim of this study was to evaluate the fatigue behavior of strength-graded zirconia polycrystals used as monolithic three-unit implant-supported prosthesis; complementarily, crystalline phase and micromorphology were also assessed. Fixed prostheses with 3 elements supported by 2 implants were confectioned, as follows: Group 3Y/5Y - monolithic structures of a graded 3Y-TZP/5Y-TZP zirconia (IPS e.max® ZirCAD PRIME); Group 4Y/5Y - monolithic structures of a graded 4Y-TZP/5Y-TZP zirconia (IPS e.max® ZirCAD MT Multi); Group Bilayer - framework of a 3Y-TZP zirconia (Zenostar T) veneered with porcelain (IPS e.max Ceram). The samples were tested for fatigue performance with step-stress analysis. The fatigue failure load (FFL), the number of cycles required until failure (CFF), and the survival rates in each cycle were recorded. The Weibull module was calculated and the fractography analyzed. The crystalline structural content via Micro-Raman spectroscopy and the crystalline grain size via Scanning Electron microscopy were also assessed for graded structures. Group 3Y/5Y showed the highest FFL, CFF, probability of survival, and reliability (based on Weibull modulus). Group 4Y/5Y showed significantly superior FFL and probability of survival than group bilayer. Fractographic analysis revealed catastrophic flaws in the monolithic structure and cohesive fracture of porcelain in bilayer prostheses, all originating from the occlusal contact point. The graded zirconia presented small grain size (≤0.61 µm), with the smallest values at the cervical region. The main composition of graded zirconia was of grains at tetragonal phase. The strength-graded monolithic zirconia, especially the 3Y-TZP/5Y-TZP, showed to be promising for use as monolithic three-unit implant-supported prosthesis.
Subject(s)
Ceramics , Dental Porcelain , Materials Testing , Ceramics/chemistry , Reproducibility of Results , Surface Properties , Dental Stress Analysis , Zirconium/chemistry , Prostheses and Implants , Yttrium/chemistryABSTRACT
OBJECTIVE: To analyze simplified adhesive containing pure or silanized bioglass 45S5 (with calcium) or Sr-45S5 (strontium-substituted) fillers applied on dentin and to evaluate the microtensile bond strength (µTBS), interface nanoleakage, degree of conversion of adhesive, collagen degradation and remineralization. METHODS: Ambar Universal adhesive (FGM) was doped with 10 wt% bioactive glasses to form following groups: Control (no bioglass), 45S5 (conventional bioglass 45S5), Sr-45S5 (Sr-substituted bioglass 45S5), Sil-45S5 (silanized bioglass 45S5) and Sil-Sr-45S5 (silanized bioglass Sr-45S5). Adhesives were applied after dentin acid-etching using phosphoric acid at extracted human molars. Resin-dentin sticks were obtained and tested for µTBS, nanoleakage at 24 h or 6 months. Degree of conversion was measured using micro-Raman spectroscopy. Dentin remineralization was assessed by FTIR after 6-month storage in PBS. Hydroxyproline (HYP) release was surveyed by UV-Vis spectroscopy. Statistical analysis was performed using ANOVA and Tukey's test (p < 0.05). RESULTS: Regarding µTBS, Sr-45S5 and 45S5 presented higher and stable results (p > 0.05). Control (p = 0.018) and Sil-Sr-45S5 (p < 0.001) showed µTBS reduction after 6-month aging. Sil-Sr-45S5 showed higher HYP release than that obtained in the 45S5 group. Sil-45S5 showed mineral deposition and increase in µTBS (p = 0.028) after 6-months. All experimental adhesives exhibited higher degree of conversion compared to Control group, except for 45S5. All adhesives created gap-free interfaces, with very low silver impregnation, except for Sil-Sr-45S5. SIGNIFICANCE: The incorporation of silanized 45S5 bioglass into the universal adhesive was advantageous in terms of dentin remineralization, bonding performance and adhesive polymerization. Conversely, Sil-Sr-45S5 compromised the µTBS, interface nanoleakage and had a negative impact on HYP outcomes.
Subject(s)
Dental Bonding , Dental Cements , Humans , Resin Cements/chemistry , Collagen , Dentin , Tensile Strength , Dentin-Bonding Agents/chemistry , Materials Testing , AdhesivesABSTRACT
Objective: To evaluate different concentrations of solvents (tetrahydrofuran (THF) and dimethyl sulfoxide (DMSO) and monomers on the degree of conversion, microtensile bond strength, and mechanical properties of experimental resin infiltrants. Materials and Methods: Resin infiltrants were formulated and divided into eleven groups: (1) Icon, (2) 75% TEGDMA (T) +25% UDMA (U), (3) T +25% BIS-EMA (B), (4) T + U +0.5%DMSO, (5) T + U +5% DMSO, (6) T + U +0.5% THF, (7) T + U +5% THF, (8) T + B +0.5% DMSO, (9) T + B +5% DMSO, (10) T + B +0.5% THF, and (11) T + B +5% THF. One hundred and ten bovine mandibular incisors were sectioned, treated, and destined to the degree of conversion, tensile cohesive strength, microtensile bond strength, flexural strength, and elastic modulus. Data were submitted to one-way ANOVA and Tukey's test (α = 0.05). Results: The degree of conversion was lowest for T + B +5%THF (41.9%) and highest for T + U +5%THF (62.1%). In flexural strength and E-modulus, the T + B (96.5 MPa and 0.49 GPa) obtained the highest values and the lowest for T + U +5% DMSO (18.5 MPa and 9.7 GPa). Icon showed the highest bond strength (19.3 MPa) and cohesive strength (62.2 MPa), while T + U +5%DMSO (9.7 MPa) and T + B +5% DMSO (9.8 MPa) the lowest values and T + B +0.5% DMSO (12.3 MPa) the lowest cohesive strength. Conclusions: The addition of lower concentrations of DMSO or THF (0.5%) did not impair bond strength or significantly affect monomer conversion, but reduced the mechanical properties of resin infiltration.
Subject(s)
Composite Resins , Dimethyl Sulfoxide , Cattle , Animals , Solvents/chemistry , Composite Resins/chemistry , Materials Testing , Tensile StrengthABSTRACT
The study investigated allogenic pulp transplantation as an innovative method of regenerative endodontic therapy. Three patients were selected for the endodontic treatment of single-root teeth, who also had a son/daughter with deciduous teeth or third molars scheduled for extraction. Receptor teeth were endodontically instrumented and irrigated using a tri-antibiotic solution. During the transplant procedures, the teeth from the son/daughter were extracted, sectioned, and the pulp was carefully removed. The harvested pulp from the donor was inserted into the root canal of the host tooth (father/mother), followed by direct pulp capping and resin composite restoration. The teeth were followed-up with for 2 years and were surveyed with computed tomography, the electric pulp vitality test, and Doppler ultrasound examination. At the 6-month follow-up, positive pulp vitality and the formation of periapical lesions were verified in cases 1 and 2. Case 3 showed remarkable periapical radiolucency before transplantation, but after 1 year, such lesions disappeared and there was positive vitality. All teeth were revascularized as determined by Doppler imaging after 2 years with no signs of endodontic/periodontal radiolucency. In conclusion, although this was a case series with only three patients and four teeth treated, it is possible to suppose that this allogenic pulp transplantation protocol could represent a potential strategy for pulp revitalization in specific endodontic cases.
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OBJECTIVES: The aim of this study was to evaluate the influence on MMP inhibition, dentin adhesion and physicochemical properties of an adhesive system incorporated with polymerizable collagen crosslinker monomer derived from cardanol. METHODS: The intermediary cardanol epoxy (CNE) was synthesized through cardanol epoxidation, followed by synthesis of cardanol methacrylate through methacrylic acid solvent-free esterification. Zymographic analysis was performed to evaluate the substances' ability to inhibit gelatinolytic enzymes. Collagen crosslinkers were added into adhesives systems according to the following groups: Ybond Universal® (Control), Ybond® + 2 % proanthocyanidin (PAC), Ybond® + 2 % unsaturated cardanol (Cardanol) and Ybond® + 2 % cardanol methacrylate (CNMA). Degree of conversion (DC) of the adhesives was assessed by FT-IR. Disk-shaped specimens were prepared for water sorption (WS) and solubility (SL) tests. Human third molars were sectioned to expose medium dentin and restored according to the different adhesives used (n = 5). Then, the specimens were cut into 1 mm2 sticks to evaluate, after 24 h and 6-month aging, microtensile bond strength (µTBS) and nanoleakage by scanning electron microscopy. Data were analysed with ANOVA and Tukey's post-test (α = 0.05). RESULTS: CNMA and PAC completely inhibited all forms of gelatinolytic enzymes. Cardanol achieved a significantly lowest DC, while the other groups did not differ from each other (p > 0.05). PAC achieved significantly higher water sorption, while CNMA solubility was significantly lower when compared to the other adhesives (p < 0.05). PAC provided a statistically higher 24 h and 6-month aging bond strength. Intermediary similar µTBS were presented by control and CNMA (p = 0.108). All adhesives applied attained significantly reduced bond strength after aging (p < 0.05). Interfaces created using CNMA were almost devoid of silver deposits initially, however all groups showed large amounts of silver deposits on resin-dentin interface subjected to water aging. SIGNIFICANCE: Although CNMA was effective in inhibiting gelatinolytic enzymes, when incorporated into a universal adhesive it could not promote less degradation of the adhesive interface after water aging. Since it is a hydrophobic monomer, CNMA did not interact well with dentin collagen, however it reduced the solubility of the adhesive system besides not interfering in its polymerization.
Subject(s)
Dental Bonding , Proanthocyanidins , Collagen , Dentin , Dentin-Bonding Agents/chemistry , Humans , Materials Testing , Methacrylates/chemistry , Phenols , Resin Cements/chemistry , Silver , Spectroscopy, Fourier Transform Infrared , Tensile Strength , WaterABSTRACT
The aim of the study was to evaluate how the association of solvents (tetrahydrofuran [THF], dimethyl sulfoxide [DMSO], ethanol [ET] or acetone [ACT]) with experimental dental adhesives affects selected properties of experimental dental adhesives and dentin bond durability. Six adhesive combinations were prepared containing: 30 % ET, 30 % ACT, 30 % THF, 28 % ET + 2 % DMSO (ET+DMSO), 15 % ethanol + 15 % THF (ET+THF), or 28 % THF + 2 % DMSO (THF+DMSO). Thirty-six molars (n = 6) were cut to expose the coronary dentin, and were randomly divided according to the adhesives. They were restored, and then cut into resindentin sticks (1 mm²), and stored in distilled water for 24 h or 6 months, until conducting the microtensile bond strength and nanoleakage tests. Other experiments performed with adhesives included viscosity assessment using a rheometer, and degree of conversion using Fourier-transform infrared spectroscopy (FTIR). The data were analyzed statistically using two-way ANOVA and Tukey's test (p < 0.05). The adhesive formulated exclusively with THF showed the highest viscosity, followed by ET+THF, which obtained the highest degree of conversion compared to ET, and THF alone. ET+DMSO obtained the highest 24-h and aged bond strengths (p < 0.05). ET+THF increased the nanoleakage slightly after 6 months, but attained the only gap-free adhesive interface among all the groups. The combination of alternative solvents, particularly THF, with conventional ones (ET) has improved chemical properties, and the dentin bonding of experimental simplified adhesives.
Subject(s)
Dental Bonding , Dentin-Bonding Agents , Dental Bonding/methods , Dentin , Dentin-Bonding Agents/chemistry , Dimethyl Sulfoxide , Ethanol , Materials Testing , Resin Cements/chemistry , Solvents/chemistry , Tensile StrengthABSTRACT
This study aimed at evaluating the influence of glass-fiber post (GFP) relining with composites of different opacities on resin cement layer thickness (CLT), bond strength (BS) to root dentin, and resin cement degree of conversion (DC%). Standardized roots of 52 bovine incisors had their canals prepared and were distributed into 4 groups (n = 10 for CLT and BS; n = 3 for DC%) according to the post used: WP3 (Control)-Whitepost DC3; groups DE, EN and TR-Whitepost DC0.5 relined, respectively, with dentin, enamel, and translucent shade composites. After cementation, specimens were sectioned into six 1.0 mm-thick discs that were submitted to push-out BS test. CLT and failure pattern were evaluated using a stereomicroscope and DC% by micro-Raman spectroscopy. Data were analyzed by two-way ANOVA and Tukey test (α = 0.05). The control group showed greater CLT than all relined groups (p < 0.05), which did not differ from each other (p > 0.05). Groups relined with low opacity composites (TR; EN) showed the highest BS and DC% means (p < 0.05). BS was not different among root thirds (p > 0.05), while DC% decreased from cervical to apical third (p < 0.05). Adhesive failures between cement and dentin were predominant, except for group DE with frequent mixed failures. It could be concluded that composite opacity did not influence CLT, which was thinner when GFP were relined and that relining GFP with lower opacity composites led to higher BS and DC%.
Subject(s)
Dental Bonding , Post and Core Technique , Animals , Cattle , Composite Resins/chemistry , Dental Bonding/methods , Dental Cements , Dental Materials/chemistry , Dental Pulp Cavity , Dentin , Glass , Materials Testing , Resin Cements/chemistryABSTRACT
The purpose was to evaluate the effect of tris(trimethylsilyl)silane (TTMSS) associated with diphenyl iodonium hexafluorophosphate (DPIHP) on the polymerization shrinkage stress (PSS), mechanical properties, color change (CC), and degree of conversion (DC) of resin-based composites (RBCs). Experimental RBCs containing 35 wt% of organic matrix (10.2 wt% BisGMA, 11.1 wt% BisEMA10 and UDMA and 2.1 wt% TEGDMA) and 65 wt% filler (13 wt% fumed silica and 52 wt% BaBSiO2) were assigned to six groups: control (0.2 wt% CQ, 0.5 wt% DMAEMA); TD05 (0.2 wt% CQ, 0.5 wt% TTMSS, 0.5 wt% DPIHP); TD10 (0.2 wt% CQ, 1 wt% TTMSS, 0.5 wt% DPIHP); DTD (0.2 wt% CQ, 0.25 wt% of DMAEMA, 0.25 wt% TTMSS, 0.5 wt% DPIHP); DT (0.2 wt% CQ, 0.25 wt% DMAEMA, 0.25 wt% TTMSS); and T05 (0.2 wt% CQ, 0.25 wt% TTMSS). The experimental formulations were submitted to the following tests: DC; PSS; CC; rate of polymerization (Rp); depth of cure by Knoop hardness; flexural strength; and flexural modulus. TTMSS showed no effect on the DC, Rp, and mechanical properties of the RBCs. DMAEMA reacted with TTMSS and reduced the Rp; the RBCs containing no DMAEMA showed no reduction in CC. DT showed the lowest PSS mean value among the groups. TTMSS differed from DMAEMA only when used in combination with DPIHP, which significantly improved the DC, maximum Rp, and mechanical properties of the RBCs tested. Based on the artificial ageing results, TTMSS was ineffective in reducing CC in the RBCs tested.
Subject(s)
Composite Resins , Methacrylates , Biphenyl Compounds , Bisphenol A-Glycidyl Methacrylate/chemistry , Composite Resins/chemistry , Dental Materials , Materials Testing , Methacrylates/chemistry , Polyethylene Glycols/chemistry , Polymerization , Polymethacrylic Acids/chemistry , SilanesABSTRACT
OBJECTIVE: To evaluate the influence of shades of a multilayered zirconia on light transmission, resin cement degree of conversion, and shear bond strength of resin cement. MATERIALS AND METHODS: The light transmission through opaque (OPQ) and translucent (TNS) regions of Katana UTML zirconia (Kuraray Noritake Dental) were evaluated for using a spectroradiometer (n = 5). Degree of conversion of dual-cure resin cement (Panavia V5, Kuraray Noritake Dental) was measured after light-activation through OPQ or TNS regions and direct exposure. Composition of the zirconia was analyzed with energy dispersive x-ray spectroscopy (EDS). Shear bond strength (SBS) was evaluated on the OPQ and TNS regions after 24 h and 1 year from specimen preparation (n = 15). RESULTS: The OPQ region produced higher irradiance loss (95.1%) than TNS one (92.9%), and lower degree of conversion (52.4%) than TNS (71.2%) at 24 h post-light activation. EDS analysis did not show differences on the microstructure of the OPQ and TNS regions. There were no significant differences on the SBS between zirconia regions. For both zirconia regions, a significant reduction on the SBS occurred after aging, being 31.7% for OPQ and 38% for TNS. CONCLUSION: Both OPQ and TNS regions affected the light transmission through the multilayered zirconia. The OPQ region yielded the highest light attenuation and the lowest degree of conversion of resin cement. Different regions of the zirconia did not influence the SBS. Clinical significance Although opaque and translucent regions of the multilayered zirconia reduced the light transmission from LED curing unit and the degree of conversion of resin cement, the regions did not affect the resin cement adhesion.
Subject(s)
Dental Bonding , Resin Cements , Ceramics/chemistry , Dental Stress Analysis , Materials Testing , Resin Cements/chemistry , Surface Properties , Zirconium/chemistryABSTRACT
Abstract: The aim of the study was to evaluate how the association of solvents (tetrahydrofuran [THF], dimethyl sulfoxide [DMSO], ethanol [ET] or acetone [ACT]) with experimental dental adhesives affects selected properties of experimental dental adhesives and dentin bond durability. Six adhesive combinations were prepared containing: 30 % ET, 30 % ACT, 30 % THF, 28 % ET + 2 % DMSO (ET+DMSO), 15 % ethanol + 15 % THF (ET+THF), or 28 % THF + 2 % DMSO (THF+DMSO). Thirty-six molars (n = 6) were cut to expose the coronary dentin, and were randomly divided according to the adhesives. They were restored, and then cut into resindentin sticks (1 mm²), and stored in distilled water for 24 h or 6 months, until conducting the microtensile bond strength and nanoleakage tests. Other experiments performed with adhesives included viscosity assessment using a rheometer, and degree of conversion using Fourier-transform infrared spectroscopy (FTIR). The data were analyzed statistically using two-way ANOVA and Tukey's test (p < 0.05). The adhesive formulated exclusively with THF showed the highest viscosity, followed by ET+THF, which obtained the highest degree of conversion compared to ET, and THF alone. ET+DMSO obtained the highest 24-h and aged bond strengths (p < 0.05). ET+THF increased the nanoleakage slightly after 6 months, but attained the only gap-free adhesive interface among all the groups. The combination of alternative solvents, particularly THF, with conventional ones (ET) has improved chemical properties, and the dentin bonding of experimental simplified adhesives.
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OBJECTIVES: To investigate physicochemical properties, dentin bonding, cytotoxicity, and in vivo pulp response of experimental self-adhesive composites tailored to direct pulp capping. MATERIALS AND METHODS: Experimental composites were prepared with beta-tricalcium phosphate and hydroxyapatite nanoparticles adsorbed with simvastatin and glutathione added at 0% (control resin), 1 wt% (Res 1%), and 10 wt% (Res 10%). A commercial light-curable calcium hydroxide (Ca(OH)2) (Ultra-Blend Plus) was used as control material. The physicochemical properties investigated were flexural strength and modulus, calcium release, and degree of conversion. Dentin bonding was assessed by the push-out test. Proliferation and cell counting assays were performed to evaluate in vitro cytotoxicity using fluorescence microscopy. In vivo pulp capping was performed on molars of Wistar rats, which were euthanized after 14 days and evaluated by histological analysis. RESULTS: No statistical difference was observed in flexural strength and cell viability (p > 0.05). Res 10% presented higher modulus than control resin and Ca(OH)2. Also, Res 10% attained statistically higher degree of conversion when compared to other experimental composites. Ca(OH)2 showed higher calcium release after 28 and 45 days of storage, with no statistical difference at 45 days to Res 10%. All experimental composites achieved significantly higher bond strength when compared to Ca(OH)2. While no significant difference was observed in the cell proliferation rates, resins at lower concentrations showed higher cell viability. In vivo evaluation of pulp response demonstrated no pulp damage with experimental composites. CONCLUSIONS: The experimental composite investigated in this study achieved adequate physicochemical properties with minor in vivo pulpal inflammation and proved to be a valuable alternative for direct pulp capping.
Subject(s)
Dental Pulp Capping/methods , Pulpitis/drug therapy , Animals , Calcium Hydroxide/administration & dosage , Calcium Phosphates/administration & dosage , Cells, Cultured , Composite Resins/administration & dosage , Durapatite/administration & dosage , Humans , Molar/drug effects , Rats , Rats, Wistar , Root Canal Therapy/methodsABSTRACT
The aim of this study was to develop a novel method of endodontic therapy, which we refer to as dental pulp autotransplantation. Three patients (2 males and 1 female) were selected for endodontic treatment of a uniradicular premolar and extraction of a third molar (without odontosection). Electric assessment of pulp vitality and computed tomographic imaging were undertaken followed by endodontic access and instrumentation using triantibiotic solution for irrigation in the host tooth. A few minutes before the transplant procedure, the third molar was extracted, the tooth was sectioned with a diamond blade in a low-speed handpiece, and the pulp was carefully removed. After premolar instrumentation, the harvested and preserved pulp tissue was reinserted into the root canal followed by direct pulp capping performed using Biodentine (Septodont, Saint-Maur-des-Fossés, France), a liner of resin-modified glass ionomer cement and composite resin restoration. The teeth were followed up for at least 12 months after the procedures and were analyzed using computed tomographic imaging, electric pulp vitality testing, and Doppler ultrasound examination. At the 3- and 6-month follow-ups, positive pulp vitality and regression of periapical lesions were verified. After 9-12 months, all teeth were revascularized as determined by Doppler imaging, and the tooth vitality was reestablished with no signs of endodontic/periodontal radiolucency or complications. Within the limitations of the study, considering that it was a case series with only 3 patients, we described a highly innovative procedure of pulp autotransplantation, which appears to be feasible, highlighting the potential for clinical application of pulp regeneration using this new modality of endodontic therapy.
Subject(s)
Dental Pulp , Regeneration , Dental Pulp Necrosis , Female , Follow-Up Studies , Humans , Male , Root Canal Therapy , Transplantation, AutologousABSTRACT
PURPOSE: To evaluate the effects of pretreatment with different crosslinking agents on glass-fiber-post adhesive luting. MATERIALS AND METHODS: Single-rooted human teeth (n = 20) were randomly assigned to four groups: proanthocyanidins (PA) from grape-seed extract, cardol and cardanol (separated from cashew nut-shell liquid) and negative control (hydroethanolic solution). The solutions were applied on 37% phosphoric acid-etched dentin for 60 s. Glass-fiber posts were cemented using a three-step etch-and-rinse adhesive (Scotchbond Multi-Purpose, 3M Oral Care) and composite cement (RelyX ARC, 3M Oral Care). Slices for the push-out bond strength test were cut and tested after 24-h or 6-month storage in distilled water. The dentin underlying the adhesive layer was analyzed by micro-Raman spectroscopy to evaluate vibrational formation of collagen crosslinks. Three additional slices per group were also made and the adhesive in-situ degree of conversion (DC) was analyzed by micro-Raman spectroscopy. The results were analyzed using two-way ANOVA and Tukey's test (p < 0.05). RESULTS: No statistically significant changes in bond strength were found over time for any of the groups, except with cardol, which increased bond strength (8.4 ± 3.9 MPa at 24 h to 15.0 ± 2.9 MPa after 6 months, p < 0.001) after aging. The formation of peaks at 1117 cm-1 and 1235 cm-1 showed the presence of collagen crosslinks for all three biomodification agents. The DC outcomes showed no statistically significant differences between groups (p = 0.514). CONCLUSION: Biomodification agents did not impair adhesive polymerization. Cardol demonstrated a positive influence on intraradicular dentin bonding for glass-fiber post luting.
Subject(s)
Post and Core Technique , Dental Cements , Dental Materials , Dentin , Humans , Tooth RootABSTRACT
OBJECTIVE: This study evaluated physical and mechanical properties and characterized the filler particles of seven composites. MATERIALS AND METHODS: Filtek Supreme (FS, 3M Oral Care), Forma (FO, Ultradent), Charisma Diamond (CD, Kulzer), Spectra Smart (SS, Dentsply), Filtek Bulk Fill (FB, 3M Oral Care), Tetric N-Ceram Bulk Fill (TB, Ivoclar), and Cention N (Ivoclar) in self- (CNSC) or dual-curing (CNDC) were evaluated. Fillers size, shape, and content were analyzed by scanning electron microscopy (SEM) and X-ray dispersive energy spectroscopy (EDX). Disk-shaped specimens (n = 5) were prepared for sorption (SP) and solubility (SL). Flexural strength and elastic modulus were tested at 24 h and 12 months (n = 10). Degree of conversion (DC%) and maximum rate of polymerization (Rpmax) were evaluated using micro-Raman spectroscopy. SP and SL results were submitted to Kruskal-Wallis one-way ANOVA and Dunn's pairwise test (α = 0.05). Mechanical properties were analyzed by 2-way ANOVA and Tukey's test (α = 0.05). DC% of CNSC and CNDC was compared by independent t-test (α = 0.05). Rpmax results were analyzed by 1-way ANOVA and Tukey's test (α = 0.05). RESULTS: The composites differed regarding filler size, shape, and content. CD and CNSC showed lower SP than FS. SS had lower SL than CNSC and CNDC. CNDC presented higher DC% than CNSC. CD, TB, and CNDC showed the highest Rpmax. TB, CNSC, and CNDC showed the lowest 24-h flexural strengths. Mechanical properties of CD did not decrease, while FO, TB, and CNSC showed a significant reduction after storage. CONCLUSIONS: Monomer composition and fillers characteristics greatly influenced the physico-mechanical properties of the tested composites.
Subject(s)
Composite Resins , Flexural Strength , Elastic Modulus , Materials Testing , Polymerization , Solubility , Surface PropertiesABSTRACT
BACKGROUND: This study aimed to evaluate the X-linked hypophosphatemic rickets (XLHR)-related compositional and microhardness tooth aspects. MATERIAL AND METHODS: One affected and one non-affected teeth by XLHR were sectioned transversely, and each section was separated for Micro-Raman spectroscopy, Knoop microhardness and scanning electron microscopy with energy dispersive x-ray microanalysis (SEM-EDS). The outcomes of these analyses were assessed. RESULTS: Outcomes of Raman analysis of inorganic/organic components (~958/~1250+~1450 cm-1) and carbonate/phosphate (~1070/~958 cm-1) ratios showed areas of altered enamel and dentin (interglobular dentin, calcospherites, and mantle dentin) with an increase of inorganic content in the rickets tooth. Microhardness reduction was observed in the affected tooth, with a more evident drop in regions of mantle dentin, interglobular dentin, and calcospherites. SEM-EDS analysis showed demonstrated the absence of calcium and phosphorus in interglobular spaces. CONCLUSIONS: In conclusion, compositional and structural deficiencies were observed in deciduous tooth affected by XLHR. Also, it was observed the absence of hydroxyapatite in the interglobular dentin by using Raman spectroscopy analysis. Key words:Dentin, dentin permeability, X-linked hypophosphatemic rickets, tooth, tooth calcification, Raman spectroscopy.