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1.
Niger J Clin Pract ; 24(6): 828-832, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34121729

RESUMEN

Background: Temporary stage in crowns and bridgework plays an important role in the success and failure of the final restorations. Lack of marginal seal of the temporary restorations can lead to further complications. Recently, digital dentistry has been improved in terms of marginal integrity. Aims: The aim of this study was to evaluate and compare the marginal leakage between CAD/CAM and conventionally made Polymethyl methacrylate (PMMA) interim crowns cemented with different temporary luting cements. Materials and Methods: Sixty resin dies of a maxillary right first premolar were prepared according to the protocol of the tooth preparation for all-ceramic crown. Interim crowns were then fabricated and assigned to two main groups according to the fabrication technique (CAD/CAM technique and conventional technique). Furthermore, the samples were sub-grouped (n = 10) according to the type of the luting cements: Zinc oxide eugenol (RelyX temp E), Zinc oxide non-eugenol (RelyX temp NE), and Zinc polycarboxylate cement (pentron). The specimens were then subjected to thermocycling at 5°C and 55°CC for 30 sec and transfer time of 15 seconds for 1500 cycles. After that, the specimens were immersed in a 2% methylene blue solution for 24 hours. The cemented specimens were sectioned buccolingually and the amount of marginal leakage was evaluated under digital microscope at magnification 50x. The scores of dye penetration were recorded and analyzed using one-way ANOVA at P < 0.05 for all tests. Results: For the fabrication technique, CAD/CAM-made interim crowns had significantly better performance in terms of lower microleakage in comparison to conventionally built interim crowns (P < 0.001). Overall, Zinc Oxide non-eugenol also showed significantly least microleakage as a luting cement then Zinc Oxide Eugenol and the most microleakage was found with Zinc Polycarboxylate regardless of the fabrication method. Conclusion: Interim crowns fabricated by CAD-CAM system are better suited for temporization. Zinc-oxide non-eugenol cements showed the least amount of microleakage in both types of crown.


Asunto(s)
Diseño Asistido por Computadora , Coronas , Cementación , Cementos Dentales , Cementos de Ionómero Vitreo , Ensayo de Materiales , Cementos de Resina , Preparación del Diente
2.
Int J Mol Sci ; 22(11)2021 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-34067318

RESUMEN

The effects of a new material based on hydroxyapatite and calcium silicates, named ALBO-MPCA, were investigated on the liver, kidney and spleen. The material was administrated orally for 120 days in an in vivo model in Wistar rats, and untreated animals served as a control. Hematological and biochemical blood parameters were analyzed. Qualitative histological analysis of tissues, change in mitotic activity of cells, and histological characteristics was conducted, as well as quantitative stereological analysis of parenchymal cells, blood sinusoids, and connective tissues. Additionally, the protein expressions of Ki67 and CD68 markers were evaluated. Histological analysis revealed no pathological changes after the tested period. It showed the preservation of the architecture of blood sinusoids and epithelial cells and the presence of mitosis. Additionally, the significantly increased number of the Ki67 in the presence of ALBO-MPCA confirmed the proliferative effect of the material noticed by stereological analysis, while immunoreactive CD68 positive cells did not differ between groups. The study showed non-toxicity of the tested material based on the effects on the hematological, biochemical, and observed histological parameters; in addition, it showed evidence of its biocompatibility. These results could be the basis for further steps toward the application of tested materials in endodontics.


Asunto(s)
Materiales Biocompatibles/farmacología , Compuestos de Calcio/farmacología , Cementos Dentales/farmacología , Durapatita/farmacología , Riñón/efectos de los fármacos , Hígado/efectos de los fármacos , Silicatos/farmacología , Bazo/efectos de los fármacos , Animales , Antígenos CD/metabolismo , Antígenos de Diferenciación Mielomonocítica/metabolismo , Antígeno Ki-67/metabolismo , Riñón/metabolismo , Hígado/metabolismo , Masculino , Ensayo de Materiales/métodos , Ratas , Ratas Wistar , Bazo/metabolismo
3.
J Adhes Dent ; 23(3): 187-200, 2021 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-34060299

RESUMEN

PURPOSE: A systematic review and meta-analysis was conducted to compare the retention rates of 3-step etch-and-rinse (3ER) adhesives with 1-step self-etch (1SE) adhesives in noncarious cervical lesions (NCCLs). The secondary outcomes were marginal integrity and marginal discoloration. MATERIALS AND METHODS: Only randomized clinical trials (RCTs) that compared 1SE with 3ER in NCCLs were included. Controlled vocabulary and keywords were combined in the search strategy for PubMed/Medline, LILACS, BBO, Web of Science, Cochrane Library, grey literature, and IADR abstracts (1990-2018). The Cochrane Risk of Bias tool (RoB) was applied to eligible studies. Meta-analyses were conducted for retention rate and secondary outcomes at different follow-up times, using the random effects model. Heterogeneity was assessed with the Cochran Q test and I2 statistics. The GRADE approach was used to assess the quality of the evidence. RESULTS: After the removal of duplicates, title and abstract screening, 18 studies remained. Of these, 15 studies were used for meta-analysis. Fourteen out of these 15 were judged at "unclear" risk and 1 at "low" risk of bias. No significant differences between groups were observed in the different follow-up periods for retention rates 12 to 24 months (p = 0.66), 24 to 36 months (p = 0.21) and 60 months (p = 0.96). A significant difference in marginal integrity was found at 12 to 24 months (p = 0.04) and in marginal discoloration at 12 to 24 months (p = 0.003). CONCLUSION: There is no evidence that 3-step ER adhesives have better retention rates than 1-step SE adhesives in NCCLs.


Asunto(s)
Cementos Dentales , Recubrimientos Dentinarios
4.
J Adhes Dent ; 23(3): 201-215, 2021 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-34060300

RESUMEN

PURPOSE: Mild and intermediately strong 2-step self-etch adhesives (2SEa) have been shown to bond efficiently to dentin. In general, their bonding efficiency to enamel is inferior to that of etch & rinse adhesives (E&Ra). On the other hand, their application procedure is less elaborate, and consequently leaves less room for application mistakes. The aim of this randomized controlled trial was to evaluate the clinical performance of an intermediately strong 2SEa, as compared with that of a 3-step E&Ra after 6 years of clinical functioning. MATERIALS AND METHODS: 239 non-carious cervical lesions in 50 patients were restored with the nanohybrid composite Herculite XRV (Kerr), bonded in random order either with the 2SEa Optibond XTR ('O-XTR', Kerr) or the gold-standard control 3E&Ra Optibond FL ('O-FL', Kerr). The restorations were recalled after 1, 2 and 6 years of clinical service and examined for retention, marginal adaptation, marginal discoloration, caries occurrence, and postoperative sensitivity. Statistical analysis was performed using a logistic regression model with generalized estimating equations (2-way GEE model). RESULTS: The patient recall rate at 6 years was 94%. The overall clinical success rate was 81.9% and 80.9% for O-XTR and O-FL, respectively. In total, 42 restorations (21 O-XTR, 21 O-FL) failed because of retention loss, severe abfraction/abrasion/erosion, severe marginal defects and/or discoloration, and/or caries. A retention rate of 92.9% and 88.9% was recorded for O-XTR and O-FL, respectively. Progressive marginal deterioration was observed over the 6-year period. Small clinically acceptable marginal defects were recorded in about 70% of the restorations (O-XTR: 69.9%; O-FL: 74.1%). Regarding marginal discoloration, 37% of the O-XTR and 30.2% of the O-FL restorations showed superficial clinically acceptable marginal discoloration. Six O-XTR and 4 O-FL restorations exhibited caries at the restoration margin. No significant difference was observed between the two groups for any of the evaluated parameters (p > 0.05). CONCLUSION: After 6 years of clinical service, Class-V restorations bonded with the 2SEa performed clinically equally well as those bonded with the 3E&Ra.


Asunto(s)
Restauración Dental Permanente , Cuello del Diente , Cementos Dentales , Esmalte Dental , Adaptación Marginal Dental , Humanos
5.
J Adhes Dent ; 23(3): 217-222, 2021 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-34060301

RESUMEN

PURPOSE: To evaluate the push-out bond strength (PBS) of glass-fiber posts (GFP) in different root canal zones (cervical, middle, and apical), bonded with experimental simplified adhesives (ESAs) containing different initiator systems (camphorquinone [CQ] or phenylpropanodione [PPD]) with or without diphenyl iodonium hexafluorophosphate (DPI), in combination with a DPI-containing composite cement. MATERIALS AND METHODS: ESA blends were prepared with bisphenol glycidyl methacrylate (bis-GMA), triethylene glycol dimethacrylate (TEG-DMA), 1,3-glycerol dimethacrylate (GDMA), 2-hydroxyethyl methacrylate (HEMA), and ethanol, then divided into 12 experimental groups (n = 10) according to the initiator systems (CQ, PPD, or CQ + PPD) and the presence or absence of DPI. The roots of 120 extracted bovine incisors were prepared with #5 Largo drills and the GFP were cemented with each ESA and experimental composite cements containing 0.05 mol% of DPI. The push-out bond strength (PBS) test was performed after 24 h of storage. Failure patterns were analyzed under a stereomicroscope. Data were analyzed with split-plot two-way ANOVA and Tukey's test (α = 0.05). RESULTS: PBS was significantly higher for DPI-containing ESAs in all regions evaluated, with the group containing 0.5 CQ + 1 PPD + 0.5 DPI exhibiting the highest PBS. There was no statistically signficant difference among groups without DPI. Most failures were classified as adhesive at the cement-dentin interface. CONCLUSIONS: The combination of an adhesive and a composite cement containing DPI salt can improve GFP bonding to root dentin, even in the apical region.


Asunto(s)
Cementos Dentales , Cementos de Resina , Animales , Bisfenol A Glicidil Metacrilato , Bovinos , Materiales Dentales , Cloruro de Sodio
6.
J Adhes Dent ; 23(3): 223-230, 2021 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-34060302

RESUMEN

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.


Asunto(s)
Técnica de Perno Muñón , Cementos Dentales , Materiales Dentales , Dentina , Humanos , Raíz del Diente
7.
J Adhes Dent ; 23(3): 233-242, 2021 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-34060303

RESUMEN

PURPOSE: To investigate the effects of several etching products prior to the application of a one-step self-etch adhesive (1-SEA) or two-step self-etch adhesive (2-SEA) on enamel by microshear bond strength (µSBS) testing and observation of the adhesive-enamel interface. MATERIALS AND METHODS: Ground human enamel surfaces were randomly assigned to one of eight groups according to the combination of surface treatments (either no conditioner [NC], ME [Multi Etchant], EC [Enamel Conditioner], or KE [K-etchant Gel]) and adhesive (ADU [Adhese Universal] or SE2 [Clearfil SE Bond 2]). All groups were further divided into two subgroups: 0 or 10,000 thermal cycles (TC). Then, the µSBS test was performed. The adhesive-enamel interface after acid-base challenge and the surface structure after conditioner application were also observed. RESULTS: With 10,000 TCs, there was no statistically significant difference between ME-ADU and NC-ADU. On the other hand, the µSBS of EC-ADU or KE-ADU was significantly higher than that of NC-ADU, while that of ME-SE2 was significantly lower than NC-SE2. There was no significant difference between EC-SE2, NC-SE2, and KE-SE2. Formation of an acid-base resistance zone (ABRZ) was confirmed in all groups. However, funnel-shaped erosion, which indicates interfacial defects, was observed in the NC-ADU, ME-ADU, and ME-SE2 groups. CONCLUSION: For enamel bonding, application of EC or KE prior to ADU increased the bond strength and created a stable adhesive-enamel interface. On the other hand, SE2 also had stable shear bond strength and interface without the use of conditioners. However, ME decreased the bonding performance of SE2.


Asunto(s)
Grabado Ácido Dental , Recubrimiento Dental Adhesivo , Cementos Dentales , Esmalte Dental , Humanos , Ensayo de Materiales
8.
Acta Odontol Latinoam ; 34(1): 10-17, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-34137773

RESUMEN

Dentin hypersensitivity is caused by increased dentinal permeability due to total or partial exposure of dentinal tubules, which in turn can be produced by alterations of dental structures or failure of restorative procedures. The purpose of this in vitro study was to evaluate the efficacy of the application of different kinds of adhesive systems to prevent dentin permeability before and after an erosive challenge. Fifty bovine dentin discs (6x1 mm) were prepared and the specimens were divided into 5 groups (n=10): (SB2) Single Bond 2, (SBU) Universal Single Bond, (CSB) Clearfil SE Bond, (SM) Scotchbond Multipurpose and (C) Control. Hydraulic conductance of dentin was recorded after adhesive application (HC-1) and after erosive challenge (HC-2). Dentin surface images of post-treatment and post-erosive challenge were obtained by scanning electron microscopy (SEM). Data were analyzed using Kruskal Wallis, Mann-Whitney with Bonferroni correction and Wilcoxon tests (p<0.05). Reduction in dentin permeability was observed with the application of adhesive systems (p<0.05). After the erosive challenge, dentin permeability increased for SBU and CSB (p<0.05), while SB2 and SM did not differ in HC-1 or HC-2 (p>0.05). The conventional, self-etching and universal adhesive systems reduce dentinal permeability by more than 80%, and dentin demineralization may contribute to the increased permeability of universal and self-etching systems.


Asunto(s)
Recubrimiento Dental Adhesivo , Recubrimientos Dentinarios , Animales , Bovinos , Resinas Compuestas , Cementos Dentales , Dentina , Ensayo de Materiales , Permeabilidad , Cementos de Resina , Resistencia a la Tracción
9.
Am J Dent ; 34(2): 80-86, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33940664

RESUMEN

PURPOSE: To evaluate and compare the effect on micro-tensile bond strength (µTBS) of a double layer application of three universal adhesives applied in self-etch mode to proximal dentin/cementum gingival margins of class II direct composite restorations, immediately and after 12 months water storage. METHODS: 66 molars with compound class II cavities, with gingival margin 1 mm below CEJ, were divided into three groups according to the universal adhesive used. The adhesives evaluated included All-Bond Universal (AB), Single Bond Universal (SB), and Prime&Bond Elect (PB). The groups were further subdivided according to adhesive application technique, either single layer or double layer application. All teeth were restored with the same nanofilled resin composite. µTBS were examined at a crosshead speed of 0.5 mm/minute after 24 hours or 12 months water storage. Fracture mode was assessed under stereomicroscope. Data were analyzed by two-way analysis of variance (ANOVA) followed by Tukey's post hoc test (P< 0.05). RESULTS: The double layer application µTBS values were significantly higher than single layer application in all groups. Regardless of the type of adhesive or application technique, all subgroups showed significantly decreased bond strength after aging. There were significant lower µTBS values for AB adhesive compared with the other two adhesives that demonstrated no significant differences between them. The double layer application technique was effective in enhancing µTBS values of all tested adhesives bonded to proximal dentin/cementum gingival margins compared to single layer application. Regardless of application technique, all tested adhesives were incapable of defying long-term water aging. CLINICAL SIGNIFICANCE: The double layer application technique may be recommended to enhance the bonding durability of universal adhesives to face challenges in bonding to dentin-cementum cervical margins.


Asunto(s)
Recubrimiento Dental Adhesivo , Recubrimientos Dentinarios , Cementos Dentales , Cemento Dental , Dentina , Ensayo de Materiales , Cementos de Resina
10.
Am J Dent ; 34(2): 105-109, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33940669

RESUMEN

PURPOSE: To evaluate the chemical composition and morphological properties of eroded dentin after biomodification with phosphorylated chitosan (P-Chi) and carbodiimide (EDC). METHODS: 42 bovine dentin specimens were used; 21 of these specimens were subjected to erosive challenge with 0.3% citric acid (pH = 3.2) for 2 hours. The specimens were randomly divided into six groups according to dentin substrate (sound or eroded) and biomodification [with 2.5% P-Chi, with 0.5 mol/L EDC, or no biomodification (control)]. The specimens were analyzed by Fourier-transform infrared spectroscopy (FTIR, n= 5, in triplicate) and atomic force microscopy (AFM, n= 2) to verify the phosphate, carbonate, and organic matrix absorption peaks and to investigate surface morphology, respectively. The data were analyzed with Origin 6.0. RESULTS: Dentin erosion reduced the intensity of the phosphate (1,100 cm⁻¹) and carbonate (872 cm⁻¹) related bands, which evidenced demineralization. Eroded dentin consisted of a more irregular surface containing slightly more open tubules. Modification with P-Chi removed intertubular dentin, which was compatible with surface demineralization; however, this modification obliterated dentin tubules. EDC did not promote demineralization. Biomodified dentin had a more irregular surface, irrespective of substrate type. CLINICAL SIGNIFICANCE: Eroded dentin demineralization promoted by biomodification with 2.5% phosphorylated chitosan (P-Chi) is a promising indicator for further studies and highlights the dentin intrinsic characteristics. From the point of view of dentin surface chemical analysis, more studies with P-Chi should be conducted to achieve greater interactions with surfaces and to improve the adhesive interface.


Asunto(s)
Carbodiimidas , Quitosano , Animales , Bovinos , Cementos Dentales , Dentina
11.
Int J Esthet Dent ; 16(2): 144-167, 2021 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-33969972

RESUMEN

AIM: To investigate whether: 1) in the adhesive era, a full-crown restoration in a molar tooth is more resistant compared with an overlay-type restoration; b) a posterior indirect adhesive restoration (PIAR) is similar to a sound tooth from a mechanical point of view. MATERIALS AND METHODS: Seventy extracted molars were divided into five groups (1. Butt Joint; 2. Full Bevel; 3. Shoulder; 4. Full Crown; 5. Sound Tooth (control); N = 14) and prepared with four different PIAR overlay design types (according to an adhesthetics classification). Seven expert dentists performed all the preparation and cementation phases with codified protocols. A CAD/CAM workflow was used to realize the 56 monolithic lithium disilicate restorations. The samples were tested with thermomechanical aging (margin quality data will be given in Part 2 of this article series), and the resistance to fracture was then tested and analyzed. RESULTS AND CONCLUSIONS: In terms of fracture resistance in a situation of overload and within the limitations of the present study, it is possible to conclude that the Full Bevel group showed higher fracture strength than all the other groups. All PIAR restorations performed equally or better than the natural control tooth in the Sound Tooth group. The Full Crown group did not perform better than partial overlay PIAR. The fracture types were limited to the crown in 50% or more of the samples; the rest involved the cervical part of the root. The preparation design that involved the root the least was the Full Crown group (14%).


Asunto(s)
Cementos Dentales , Porcelana Dental , Cementación , Diseño Asistido por Computadora , Coronas , Diseño de Prótesis Dental , Fracaso de la Restauración Dental , Análisis del Estrés Dental , Humanos , Ensayo de Materiales , Diente Molar
12.
Arch Oral Biol ; 127: 105148, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34022546

RESUMEN

OBJECTIVE: The aim of this study was to synthesize and characterize an experimental primer containing cationic lipid nanoparticles (NPL-chitosan) and to evaluate its properties. DESIGN: The NPL-chitosan were synthesized by emulsion and sonication method. The experimental primers were applied in dentin surface of fifty human molars. The experimental groups were: 1) application of commercial primer; 2) Primer containing 2% of Chlorhexidine (CHX) 3); Primer with 2% NPL-chitosan 4); Primer with 0.6 % of NPL-chitosan 5); Primer with 0.4 % of NPL-chitosan. A composite resin plateau was used for the analysis, where sections were made for making the dentin beams. The effect of experimental primer with cationic nanoparticles in the inhibition of matrix metalloproteinase (MMP) activity was carrying out by in situ zymography. For the Resin-Dentin Adhesive Strength and in situ Zymography analysis, was used the One-way analysis of variance (ANOVA) with significance level of 95 %. RESULTS: Spherical NPL-chitosan presented size below 220 nm, polydispersity index of 0.179 and zeta potential positive and was stable over 75 days. These nanoparticles showed antibacterial activity agsainst S. mutans with MIC of the 0.4 % and MBC of 0.67 %. In the Microtensile Strength, no statistical difference was observed between the experimental groups (p = 0.9054). The in situ zymography assay showed that the group with 2% of NPL-chitosan presented higher inactivation activity of MMPs compared to the other groups (p < 0.05). CONCLUSION: The experimental primer containing NPL-chitosan has antimicrobial activity, does not alter the adhesive resistance and inactivates MMPs present in dentin.


Asunto(s)
Quitosano , Recubrimiento Dental Adhesivo , Nanopartículas , Resinas Compuestas , Cementos Dentales/farmacología , Dentina , Recubrimientos Dentinarios , Humanos , Ensayo de Materiales , Metaloproteasas , Cementos de Resina , Resistencia a la Tracción
13.
J Appl Oral Sci ; 29: e20201031, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33950080

RESUMEN

METHODOLOGY: Fixed orthodontic appliances may lead to biofilm accumulation around them that may increase caries risk. This study aimed to evaluate the influence of quaternary ammonium methacrylates (QAMs) on the physicochemical properties, cytotoxicity, and antibacterial activity of adhesive resins for orthodontic purposes. A base resin was prepared with a comonomer blend and photoinitiator/co-initiator system. Two different QAMs were added to the base adhesive: dimethylaminododecyl methacrylate at 5 wt.% (DMADDM) or dimethylaminohexadecyl methacrylate (DMAHDM) at 10 wt.%. The base adhesive, without QAMs, (GC) and the commercial Transbond™ XT Primer 3M (GT) were used as control. The resins were tested immediately and after six months of aging in the water regarding the antibacterial activity and shear bond strength (SBS). The antibacterial activity was tested against Streptococcus mutans via metabolic activity assay (MTT test). The groups were also tested for the degree of conversion (DC) and cytotoxicity against keratinocytes. RESULTS: The resins containing QAM showed antibacterial activity compared to the commercial material by immediately reducing the metabolic activity by about 60%. However, the antibacterial activity decreased after aging (p<0.05). None of the groups presented any differences for SBS (p>0.05) and DC (p>0.05). The incorporation of DMADDM and DMAHDM significantly reduced the keratinocyte viability compared to the GT and GC groups (p<0.05). CONCLUSION: Both adhesives with QAMs showed a significant reduction in bacterial metabolic activity, but this effect decreased after water aging. Lower cell viability was observed for the group with the longer alkyl chain-QAM, without significant differences for the bonding ability and degree of conversion. The addition of QAMs in adhesives may affect the keratinocytes viability, and the aging effects maybe decrease the bacterial activity of QAM-doped materials.


Asunto(s)
Soportes Ortodóncicos , Antibacterianos , Biopelículas , Cementos Dentales , Ensayo de Materiales , Metacrilatos , Cementos de Resina , Streptococcus mutans
14.
J Clin Pediatr Dent ; 45(2): 112-116, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33951168

RESUMEN

OBJECTIVE: Calcium silicate-based cements (CSCs) may lead to coronal staining in young permanent teeth over the time. The purpose of this study was to evaluate and compare the long-term tooth discoloration induced by different CSCs. STUDY DESIGN: Ninety freshly-extracted human molars were assigned randomly into 6 groups (n=15/group) according to the CSC used as a pulpotomy material: ProRoot MTA, MTA Angelus, NeoMTA, EndoSequence Putty, Biodentine and Negative control (No cement). The color was assessed at baseline, and thereafter at 3, 6, 12 and 24 months by using both a spectrophotometer and digital images taken with and without a cross-polarizing filter. The time-dependent changes in color (ΔE) were compared within and among groups using Analysis of Variance. RESULTS: Angelus MTA and ProRooT MTA showed severe coronal discoloration (p>0.05) starting at 3 months. ΔE values of NeoMTA, EndoSequence Bioceramic Putty and Biodentine were below the perceptibility threshold, with Biodentine showing greater ΔE values than NeoMTA and EndoSequence Putty in the absence of statistical significance (p>0.05). CONCLUSIONS: Discoloration elicited by CSCs may develop soon after placement, and continue to increase for up to two years. Angelus MTA and ProRooT MTA cannot be recommended for vital pulp therapies in the esthetic zone of young individuals.


Asunto(s)
Decoloración de Dientes , Diente , Compuestos de Aluminio/efectos adversos , Compuestos de Calcio/efectos adversos , Cementos Dentales/efectos adversos , Combinación de Medicamentos , Humanos , Óxidos/efectos adversos , Pulpotomía , Silicatos/efectos adversos , Decoloración de Dientes/inducido químicamente
15.
Biomed Res Int ; 2021: 6663683, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33959664

RESUMEN

Objective: To compare the orthodontic bracket debonding force and assess the bracket failure pattern clinically between different teeth by a validated prototype debonding device. Materials and Method. Thirteen (13) patients at the end of comprehensive fixed orthodontic treatment, awaiting for bracket removal, were selected from the list. A total of 260 brackets from the central incisor to the second premolar in both jaws were debonded by a single clinician using a validated prototype debonding device equipped with a force sensitive resistor (FSR). Mean bracket debonding forces were specified to ten (10) groups of teeth. Following debonding, Intraoral microphotographs of the teeth were taken by the same clinician to assess the bracket failure pattern using a 4-point scale of adhesive remnant index (ARI). Statistical analysis included one-way ANOVA with post hoc Tukey HSD and independent sample t-test to compare in vivo bracket debonding force, Cohen's kappa (κ), and a nonparametric Kruskal-Wallis test for the reliability and the assessment of ARI scoring. Results: A significant difference (p < 0.001) of mean debonding force was found between different types of teeth in vivo. Clinically, ARI scores were not significantly different (p = 0.921) between different groups, but overall higher scores were predominant. Conclusion: Bracket debonding force should be measured on the same tooth from the same arch as the significant difference of mean debonding force exists between similar teeth of the upper and lower arches. The insignificant bracket failure pattern with higher ARI scores confirms less enamel damage irrespective of tooth types.


Asunto(s)
Cementos Dentales/química , Remoción de Dispositivos , Soportes Ortodóncicos , Adulto , Falla de Equipo , Humanos , Fenómenos Mecánicos , Diente/fisiología , Adulto Joven
16.
Int J Periodontics Restorative Dent ; 41(5146): 217-224, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33819326

RESUMEN

One of the chronic problems with traditional cement or screw retention of crowns to implants is the development of biologic and technical complications, including soft tissue complications, bone loss, screw loosening, loss of retention, and veneering material fractures. The purpose of this case series report is to document preliminary results, specifically crown retention, using a friction-fit connection of crown to abutment. A sample composed of patients who had one or more implants restored between July 1, 2019, and October 30, 2019, were enrolled in this retrospective case-control series. Each patient had their crown connected to the implant abutment using a friction-fit system. Patients were seen for routine follow-up for documentation of crown retention, and 24 crowns were followed. After 6 months of follow-up, 100% of the crowns retained retention and did not become loose under normal masticatory function. The use of a friction-fit connection provided excellent retention of the crown to the abutment over the 6-month follow-up period.


Asunto(s)
Coronas , Cementos Dentales , Tornillos Óseos , Pilares Dentales , Prótesis Dental de Soporte Implantado , Fricción , Humanos , Estudios Retrospectivos
17.
Stomatologiia (Mosk) ; 100(2): 97-102, 2021.
Artículo en Ruso | MEDLINE | ID: mdl-33874669

RESUMEN

The analysis of modern scientific data on traditional and adhesive fixation of zirconia restorations, adhesion of various cements to zirconium dioxide, methods of surface preparation of ceramic restorations is presented. Micromechanical methods of preparation for cementation of the surface of a zirconia dental prosthesis are discussed in Part 1.


Asunto(s)
Recubrimiento Dental Adhesivo , Cementos de Resina , Cerámica , Cementos Dentales , Porcelana Dental , Análisis del Estrés Dental , Humanos , Ensayo de Materiales , Propiedades de Superficie , Circonio
18.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 56(4): 342-348, 2021 Apr 09.
Artículo en Chino | MEDLINE | ID: mdl-33832035

RESUMEN

Objective: To explore the effect of subpressure on the bonding strength of resin to polycrystalline particulates modified zirconia ceramic. Methods: One hundred and twenty pre-sintered zirconia discs were prepared and divided into the control group, the sandblasting group and the 30, 50, 70 s acid etching group (24 per group) by the random number table method. There was no additional treatment in the control group and sandblasting group before sinering. The 30, 50, and 70 s acid etching groups were immersed in HF for 30, 50, 70 s, respectively, and then they were placed into CaCl2 solution for 90 s and dipped in NaOH solution at 80 ℃ for 2 h. After sintering, the sandblasting group was subjected to sandblasting. The surface tomography and roughness were tested. According to whether subpressure was applied or not after the adhesives were applied, each group was randomly divided into two subgroups with a random number table: a subpressure subgroup and a normal pressure subgroup (12 per subgroup). Resin columns were bonded to these specimens. Shear bonding strength (SBS) test was conducted and the bonding interface, fracture surface and failure mode were analyzed. Results: The surface of control group was smooth, and its roughness was (0.24±0.11) µm. The rough surface was formed after sandblasting in the sandblasting group, and its roughness was (0.95±0.12) µm. The surface roughness of 30, 50, 70 s acid etching groups [(0.60±0.15), (1.04±0.11), (1.57±0.16) µm] increased as the HF immersion time prolonged, and the difference in surface roughness of zirconia specimens among each group was statistically significant (P<0.05). The SBS values between zirconia and resin of all the subpressure subgroups, namely: the control group, the sandblasting group, and the 30, 50, 70 s acid etching group [(13.56±1.19), (20.98±2.11), (17.37±2.44), (24.19±2.97), (21.36±2.16) MPa] were significantly stronger than those in the normal pressure subgroups, namely: the control group, sandblasting group, 30, 50, 70 s acid etching group [(10.74±0.93), (18.47±2.14), (14.81±1.54), (20.74±2.56), (17.75±2.54) MPa] (P<0.05). No obvious gaps and bubbles were observed in the bonding interfaces in subpressure subgroups. The proportion of mixed failure was significantly increased after applying subpressure (P<0.05). Conclusions: The subpressure can effectively enhance the bonding strength between the resin and polycrystalline particulates modified zirconia ceramic and improve the bonding effect.


Asunto(s)
Recubrimiento Dental Adhesivo , Cementos de Resina , Cerámica , Cementos Dentales , Porcelana Dental , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Resistencia al Corte , Propiedades de Superficie , Circonio
19.
J Adhes Dent ; 23(2): 167-175, 2021 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-33825430

RESUMEN

PURPOSE: To investigate the effects of root canal irrigants, dentin surface treatment, and timing of the restoration on the microtensile bond strength (µTBS) of a universal adhesive to deep coronal dentin. MATERIALS AND METHODS: Ninety (90) intact molars were grouped according to the irrigation protocol: group 0 (saline, control group); group 1: 5.25% sodium hypochlorite (NaOCl), 17% ethylenediaminetetraacetic acid (EDTA) followed by 5.25% NaOCl; group 2: 18% etidronic acid (HEDP) + 5.25% NaOCl in a single mixture. Groups 1 and 2 were divided into 2 subgroups (n = = 10) according to the time of restoration: immediate (subgroup A) and after 7 days (subgroup B). Four other groups (n = 10) were created according to the dentin surface pretreatment and received an immediate restoration: group 3: 5.25% NaOCl - 17% EDTA and AH Plus Cleaner; group 4: 5.25% NaOCl - 17% EDTA and 100% ethanol; group 5: 5.25% NaOCl + 18% HEDP and AH Plus Cleaner; group 6: 5.25% NaOCl + 18% HEDP and 100% ethanol. µTBS testing was carried out for each subgroup and interfaces were analyzed through SEM. The µTBS was analyzed with Welch statistics and the post-hoc Games-Howell test for multiple comparisons (p < 0.05). RESULTS: Statistically significant differences were observed between test groups and control groups (p < 0.001), except for group 3 (p = 0.349). No significant differences were recorded between groups 1A (27.5 ± 8.7 MPa), 2A (32.6 ± 14.5 MPa) and 3 (27.3 ± 14.3 MPa). Group 6 (48.6 ± 11.6 MPa) exhibited the highest µTBS among all tested groups. For groups 1 and 2, significantly higher values were recorded for subgroups 1B (39.3 ± 7.6 MPa) and 2B (43.8 ± 8.3 MPa) compared to subgroups 1A (27.5 ± 8.7 MPa) and 2A (32.6 ± 14.5 MPa). CONCLUSION: When using NaOCl as root canal irrigant, it is advisable to delay the placement of a post-endodontic-treatment restoration.


Asunto(s)
Recubrimiento Dental Adhesivo , Cementos Dentales , Cavidad Pulpar , Análisis del Estrés Dental , Dentina , Ácido Edético , Ensayo de Materiales , Irrigantes del Conducto Radicular , Preparación del Conducto Radicular , Hipoclorito de Sodio
20.
Oper Dent ; 46(1): 75-86, 2021 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-33882135

RESUMEN

CLINICAL RELEVANCE: Post and core crowns and endocrowns perform similarly on fracture strength, but endocrowns have more repairable fractures.


Asunto(s)
Incisivo , Técnica de Perno Muñón , Coronas , Cementos Dentales , Fracaso de la Restauración Dental , Análisis del Estrés Dental , Dentina
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