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1.
J Adhes Dent ; 23(5): 461-467, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34549929

RESUMO

PURPOSE: To evaluate the microtensile bond strength (µTBS) of a one-step self-etch adhesive (1-SEA) to dentin and its interfacial nanomechanical properties after 8 years of water storage. MATERIALS AND METHODS: Flat coronal dentin surfaces of extracted human third molars were bonded with a 1-SEA (Clearfil S3 Bond Plus, CS3+) and built up with a hybrid resin composite (Clearfil AP-X). After storage in water for 24 h or 8 years, non-trimmed stick-shaped specimens were fabricated from the central part of each bonded tooth and subjected to the µTBS test at a crosshead speed of 1.0 mm/min. Failure modes and the morphology of debonded interfaces were analyzed using a scanning electron microscope (SEM). In addition, the elastic modulus (E) and hardness (H) of the adhesive layer and the resin composite were determined by an instrumented nanoindentation test. The acquired µTBS, E, and H data were statistically analyzed using t-tests to examine the effect of storage time (α = 0.05). RESULTS: The 8-year µTBS was slightly lower than that after 24 h, but the difference was not significant (p = 0.123). The SEM observation of debonded surfaces after 8 years revealed extrusions and lacunas. E and H of the adhesive layer and the resin composite significantly decreased over the 8-year water storage (p < 0.001). CONCLUSIONS: Although 8 years of water storage did not decrease the µTBS of CS3+ significantly, the observed failure mode patterns and significantly decreased nanomechanical properties indicated resin degradation of the adhesive and the resin composite.


Assuntos
Colagem Dentária , Dentina , Resinas Compostas , Cimentos Dentários , Análise do Estresse Dentário , Adesivos Dentinários , Humanos , Teste de Materiais , Cimentos de Resina , Estresse Mecânico , Propriedades de Superfície , Resistência à Tração
2.
Biomed Res Int ; 2021: 9987860, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34195290

RESUMO

Purpose: The potential of UV-mediated photofunctionalization to enhance the resin-based luting agent bonding performance to aged materials was investigated. Methods: Sixty samples of each material were prepared. Yttria-stabilized zirconia (YZr) and Pd-Au alloy (Pd-Au) plates were fabricated and sandblasted. Lithium disilicate glass-ceramic (LDS) was CAD-CAM prepared and ground with #800 SiC paper. Half of the specimens were immersed in machine oil for 24 h to simulate the carbon adsorption. Then, all of the specimens (noncarbon- and carbon-adsorbed) were submitted to UV-mediated photofunctionalization with a 15 W UV-LED (265 nm, 300 mA, 7692 µW/cm2) for 0 (control groups), 5, and 15 min and subjected to contact angle (Ɵ) measurement and bonded using a resin cement (Panavia™ V5, Kuraray Noritake, Japan). The tensile bond strength (TBS) test was performed after 24 h. The Ɵ (°) and TBS (MPa) data were statistically analyzed using two-way ANOVA and Bonferroni correction tests (α = 0.05). Results: In the carbon-adsorbed groups, UV-mediated photofunctionalization for 5 min significantly decreased Ɵ of all materials and increased TBS of YZr, and UV for 15 min significantly increased the TBS of LDS and Pd-Au. In noncarbon-adsorbed groups, UV-photofunctionalization did not significantly change the Ɵ or TBS except YZr specimens UV-photofunctionalized for 15 min. Conclusion: UV-mediated photofunctionalization might have removed the adsorbed hydrocarbon molecules from the materials' surfaces and enhanced bond strengths of Panavia™ V5 to YZr, LDS, and Pd-Au. Additionally, UV-mediated photofunctionalization improved the overall TBS of YZr. Further investigation on the optimum conditions of UV photofunctionalization on indirect restorative materials should be conducted.

3.
Dent Mater J ; 2021 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-34305051

RESUMO

The effect of long-term water storage on the regional ultimate tensile strength (UTS), water sorption (Wsp) and water solubility (Wsl) of conventional and bulk-fill resin composites at various depths was investigated. Composite specimens light-cured from one side were sectioned into beams corresponding to different depths (1-5 mm) and stored in water for 24 h, 1 week, 1 month, 6 months or 1 year. UTS increased during the first week and then gradually decreased over time, especially in deeper regions. Bulk-fill composites initially exhibited similar UTS at all depths, whereas the UTS of conventional composites at 1 mm and 5 mm differed significantly at all time points. Wsp and Wsl increased with depth and storage time, markedly at 3-5 mm after 1 month for conventional composites and after 6 months for bulk-fill composites. The signs of degradation at depths beyond 3 mm suggested that even bulk-fill composites have suboptimal properties in layers more than 3 mm in thickness.

4.
J Adhes Dent ; 23(4): 327-334, 2021 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-34269543

RESUMO

PURPOSE: The effect of surface moisture on bur-cut dentin on the microtensile bond strength (µTBS) of universal adhesives with various contents of 2-hydroxyethyl methacrylate (HEMA) and methacrylamide monomers was evaluated. MATERIALS AND METHODS: Flat mid-coronal dentin surfaces of human molars were exposed, and a standardized smear layer was prepared using a fine-grit diamond bur. The surfaces were either left wet or air dried for 10 s before bonding with Clearfil Universal Bond Quick (UBQ), experimental UBQ without an amide monomer (UBQexp), Scotchbond Universal (SBU), Prime&Bond Universal (PBU), or BeautiBond Universal (BBU). The specimens were built up with resin composite, sectioned into sticks and subjected to the µTBS test after 24 h or 10,000 thermal cycles. The µTBS data were analyzed using three-way ANOVA followed by pairwise comparisons with Bonferroni's correction (α = 0.05). RESULTS: The level of dentin moisture did not significantly affect µTBS of UBQ and BBU (p > 0.05). HEMA-containing UBQ, UBQexp, and SBU exhibited higher µTBS to dry dentin, while HEMA-free PBU and BBU showed higher µTBS to wet dentin. Thermocycling significantly decreased the µTBS of UBQexp (p < 0.01) and BBU (p < 0.001) irrespective of dentin moisture level, while SBU was significantly affected only on dry dentin (p < 0.001). Thermocycling had no significant effect on UBQ and PBU containing methacrylamide monomers (p > 0.05). CONCLUSION: Dry surfaces enabled obtaining optimal bonding for HEMA-containing adhesives to bur-cut dentin, while wet surfaces enabled optimal bonding for HEMA-free adhesives. Methacrylamide monomers could contribute to the improvement of the initial and long-term bonding performance of universal adhesives to bur-cut dentin.


Assuntos
Colagem Dentária , Adesivos Dentinários , Acrilamidas , Adesivos , Resinas Compostas , Cimentos Dentários , Dentina , Humanos , Teste de Materiais , Metacrilatos , Cimentos de Resina , Resistência à Tração
5.
Dent Mater J ; 40(5): 1151-1159, 2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34024886

RESUMO

The purpose of this multicenter clinical study was to compare the mid-term clinical effectiveness of direct resin composite restorations using one-step or two-step self-etch adhesives (1-SEAs or 2-SEAs). In total, 352 restorations of class I-V cavities and non-carious cervical lesions in vital teeth (1-SEAs; 52 cases, 2-SEAs; 300 cases) were placed at nine university hospitals and evaluated according to the modified USPHS criteria at baseline, and after 1, 2, and 3 years. The recall rates were 86.6% (1 year), 80.1% (2 years), and 62.2% (3 years). Two restorations failed due to fracture during the follow-up, and there was no significant difference in survival rates between 1-SEAs (97.6%) and 2-SEAs (99.4%). However, 2-SEAs exhibited significantly lower occurrences of discoloration, marginal discoloration, fracture, and plaque retention. Moreover, the subjects reported a significantly lower postoperative hypersensitivity and higher overall satisfaction at all evaluation periods if 2-SEAs were used.


Assuntos
Restauração Dentária Permanente , Colo do Dente , Resinas Compostas , Cimentos Dentários , Adaptação Marginal Dentária , Adesivos Dentinários , Humanos , Cimentos de Resina , Resultado do Tratamento
6.
Dent Mater J ; 40(4): 1033-1040, 2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-33883353

RESUMO

This study evaluated the effect of the structural color phenomenon in resin composites (RCs) on the color adjustment of restorations by investgating their color reproduction performance in human incisors of various shade. Cervical cavities were filled with a single-shade RC with 260 nm spherical fillers (Omnichroma (OMN)), conventional A2-shade RCs (Estelite Σ Quick or Clearfil AP-X), or experimental RCs with 5-50 nm fumed silica fillers (R1) and 100 nm spherical fillers (R2). Color parameters (L*C*h*) were measured using a CIE XYZ camera along the centerline of the restorations, and the color difference (∆E00) between corresponding areas of intact and restored teeth was calculated. Additionally, the reflectance spectra of OMN, R1, and R2 were investigated. OMN exhibited significantly lower ∆E00 than other tested RCs (p<0.05) and its reflection spectrum ranged from blue to red, while a blue peak was observed with R1 and R2, indicating a higher color adjustment potential of OMN.


Assuntos
Resinas Compostas , Cor , Humanos
7.
Dent Mater J ; 40(4): 877-884, 2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-33678732

RESUMO

The influence of sulfinate agents applied as a dentin pretreatment or a mixture with multi-mode one-step self-etch adhesives (1-SEAs) on the degree of conversion (DC) and micro-tensile bond strength (µTBS) of light-cured 1-SEAs was investigated. 1-SEAs Clearfil Universal Bond Quick (UBQ) or Scotchbond Universal Adhesive (SBU) were applied to dentin in etch&rinse or self-etch mode using various application strategies: 1) no pretreatment, 2) pretreatment with 90 wt% ethanol, 3) pretreatment with a sulfinate agent Clearfil DC Activator (UDC) or Scotchbond Universal DCA (SDC), or 4) a mixture of UBQ+UDC or SBU+SDC. µTBS was measured after 24 h. Additionally, DC was measured using attenuated total reflectance Fourier-transform infrared spectroscopy. Pretreatment with sulfinate agents resulted in the highest µTBS and DC, significantly improving them especially in etch&rinse mode. The mixture of sulfinate agents with 1-SEAs was less effective. Pretreatment with ethanol significantly improved µTBS in etch&rinse mode but compromised µTBS in self-etch mode.


Assuntos
Colagem Dentária , Adesivos , Resinas Compostas , Cimentos Dentários , Dentina , Adesivos Dentinários , Teste de Materiais , Cimentos de Resina , Resistência à Tração
8.
J Mech Behav Biomed Mater ; 115: 104295, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33412405

RESUMO

The bonding performance of dental adhesives is most frequently evaluated using the micro-tensile bond strength (µTBS) test. Despite lacking evidence, peripheral specimens are often discarded to avoid regional variability. This study, therefore, examined whether µTBS to central and peripheral dentin differed. Dentin surfaces of extracted human molars were bonded with various self-etch adhesives, built up with a resin composite, cut into beams, and stressed in tension. Failure mode was classified as adhesive, cohesive in dentin, or other using scanning electron microscopy. Since cohesive failures in dentin were frequent and could confound µTBS results, the data from central/peripheral dentin were analyzed using a Weibull competing risk (CR) model distinguishing failure modes, and its outcomes were compared to a conventional failure mode non-distinguishing Weibull model. Based on the strength data of cohesively failed specimens, the CR model also estimated the strength of dentin. For comparison, the ultimate tensile strength (UTS) of dentin was measured in both regions. The conventional model suggested that peripheral µTBS was higher than central µTBS. Conversely, the CR model disclosed no significant difference in µTBS between the regions but indicated a higher strength of peripheral dentin. This finding was confirmed by UTS measurements, and further supported by the significantly higher incidence of cohesive failures in central dentin. Therefore, peripheral specimens can be used in the µTBS test as well as central ones, but a CR model should be used for statistical analysis if cohesive failures in dentin are frequent, as the strength of peripheral dentin is higher.


Assuntos
Colagem Dentária , Adesivos Dentinários , Resinas Compostas , Dentina , Humanos , Teste de Materiais , Cimentos de Resina , Resistência à Tração
9.
J Prosthet Dent ; 2021 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-33431177

RESUMO

STATEMENT OF PROBLEM: The bonding of light-activated adhesives to root canal dentin with an additional touch-polymerization activator has been insufficiently examined. PURPOSE: The purpose of this in vitro study was to investigate the effect of touch-polymerization activators and extended light-irradiation time on the microtensile bond strength (µTBS) of light-activated adhesives. MATERIAL AND METHODS: Post cavities were prepared in 50 extracted mandibular premolars and bonded using Prime&Bond Universal (PBU); PBU+Self Cure Activator (SCA); Clearfil SE Bond 2 (SEB); SEB+Clearfil DC Activator (DCA); or Clearfil Universal Bond Quick ER (UBQ). After light-irradiation for 10 or 20 seconds, the post cavities were filled with dual-activated resin core materials. Eight beams were prepared per specimen and subjected to the µTBS test. The µTBS data were analyzed by using 3-way ANOVAs with the Bonferroni correction (α=.05). RESULTS: The 3-way ANOVAs indicated that the use of touch-polymerization activators (SCA and DCA) significantly increased the µTBS of PBU and SEB in both the coronal (P=.015) and apical (P=.001) regions. The extension of light-irradiation time to 20 seconds significantly improved their µTBS in the apical region (P<.001), but not in the coronal region (P=.09). Light-irradiation for 20 seconds increased the µTBS of UBQ significantly in the coronal region (P=.014). CONCLUSIONS: Touch-polymerization activators improved the bond strength of light-activated adhesives to root canal dentin, especially when combined with an extended light-irradiation time.

10.
Dent Mater J ; 40(2): 379-384, 2021 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-33100300

RESUMO

The effect of warm air-blowing on the sealing ability of two one-bottle and one two-bottle silane-containing universal adhesives (UAs) applied to lithium disilicate ceramics (LDS) was evaluated. Tapered cavities prefabricated in LDS blocks (IPS e.max CAD) were treated by the adhesives, air-blown either with normal air (23±1°C) or warm air (60±5°C), and filled with a flowable resin composite. Interfacial gap formation was observed using swept-source optical coherence tomography immediately after filling, after 24 h, 5,000 and 10,000 thermal cycles, and an additional 1-year water storage. Specimens bonded using normal air-blown one-bottle UAs exhibited a significantly higher gap formation than the two-bottle UA (p<0.001), and detached within 24 h. Warm air-blowing significantly decreased the gap formation of one-bottle UAs (p<0.001), but the specimens dislocated within 24 h or during thermocycling. The two-bottle UA withstood all aging procedures and warm air-blowing significantly decreased its 1-year gap formation compared to normal air-blowing (p=0.002).


Assuntos
Colagem Dentária , Silanos , Cerâmica , Cimentos Dentários , Porcelana Dentária , Teste de Materiais , Cimentos de Resina , Propriedades de Superfície
11.
Dent Mater J ; 40(2): 446-454, 2021 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-33162459

RESUMO

The effect of curing mode of dual-cure resin cements on the tensile bond strength (TBS) of universal adhesives to enamel, dentin, zirconia, lithium disilicate ceramics (LDS), feldspathic porcelain (FP), and a Pd-Au alloy was evaluated. The substrates were bonded using Tokuyama Universal Bond (TUB) or Scotchbond Universal Adhesive (SBU), followed by luting with Estecem II (ECII) or Rely-X Ultimate (RXU), respectively, which were used either in light-curing or self-curing mode. The TBS test was performed after 24 h or 5,000 thermal cycles. Light-curing significantly improved the 24-h TBS of TUB/ECII to enamel, dentin and FP, as well as the TBS of SBU/RXU to all substrates except LDS. After thermal cycling, light-curing significantly increased the TBS of both adhesives/cements to dentin, but significant differences between curing modes were seldom observed for other substrates. This suggested that light-curing is essential for the hydrophilic dentin, but self-curing might be sufficient for other substrates.


Assuntos
Colagem Dentária , Cimentos de Resina , Cimentos Dentários , Esmalte Dentário , Dentina , Adesivos Dentinários , Teste de Materiais , Resistência à Tração
12.
Dent Mater J ; 40(2): 385-392, 2021 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-33208575

RESUMO

This study aimed to evaluate the effect of silane coupling agent contamination on the microtensile bond strength (µTBS) of 3-step etch-and-rinse adhesives on dentin. Flat occlusal dentin surfaces were prepared and randomly divided into 8 groups (n=20) based on the tested adhesives; Scotchbond Multi-purpose or Optibond FL, with contamination of an experimental silane (2 vol% of 3-m ethacryloxypropyltrimethoxysilane at pH 4.5) before acid-etching, after-etching or after-priming; while the groups without silane contamination served as controls. µTBS data were analyzed by two-way ANOVA and Tukey's HSD tests at a significance level of 0.05. Additional specimens of contaminated dentin were used to analyze changes in the organic molecules by Fourier transform infrared spectroscopy (FTIR). Silane contamination before acid-etching did not significantly change µTBS (p>0.05), but contamination after-etching and after-priming significantly decreased µTBS of both adhesives (p<0.05). Silane contamination had an adverse effect on the dentin bond strength of 3-step etch-and-rinse adhesives especially after-priming.


Assuntos
Colagem Dentária , Adesivos Dentinários , Adesivos , Resinas Compostas , Cimentos Dentários , Dentina , Teste de Materiais , Cimentos de Resina , Silanos , Resistência à Tração
13.
Dent Mater J ; 40(3): 599-605, 2021 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-33361663

RESUMO

The effect of 1-week water storage and subsequent 10,000 thermal cycles on light transmission properties (straight-line transmission (G0), diffusion (DF), the amount of transmitted light (AV)), translucency parameter (TP) and refractive index (RI) of four nanofilled flowable composites was examined. The composites included Filtek Supreme Ultra Flowable Restorative (FSU), Estelite Flow Quick (EFQ), Estelite Universal Flow, (EUF), and Clearfil Majesty ES Flow (ESF), all of A3 shade. For composites with lower filler load (FSU, EFQ), water storage increased G0, AV and TP, but subsequent thermocycling decreased them. An opposite tendency was found for DF. Materials with higher filler load (EUF, ESF) were not significantly affected by aging conditions. RI of EFQ and EUF containing bisphenol A polyethoxy methacrylate (Bis-MPEPP) increased significantly after thermocycling. Additionally, morphological changes were observed using scanning electron microscopy which revealed cracks within nanocluster fillers and dislocation of particles in FSU and EFQ after thermocycling.


Assuntos
Refratometria , Água , Resinas Compostas , Materiais Dentários , Luz , Teste de Materiais , Metacrilatos , Microscopia Eletrônica de Varredura , Propriedades de Superfície
14.
Acta Odontol Latinoam ; 33(2): 82-89, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32920609

RESUMO

The aim of this study was to evaluate the degree of conversion, cytotoxicity, solubility and pH of photopolymerizable calciumbased cements submitted to preheating. The degree of conversion was analyzed by Fourier transform infrared, cytotoxicity by the MTT test and solubility through loss of mass. The data were subjected to statistical tests (ANOVA / Tukey's, p<0.05). The photopolymerizable materials showed a low degree of conversion, regardless of preheating. All materials caused a reduction in cell viability at 24 hours and 7 days, with the Dycal (control) being more cytotoxic. Heat had a positive effect on Biocal at 7 days. Dycal is the most soluble material. Heat had no effect on the solubility or pH of the polymerizable materials. It is concluded that photopolymerizable calcium-based cements have a low degree of conversion and are soluble, which results in mild to moderate cytotoxicity.


Assuntos
Hidróxido de Cálcio/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Cimentos Dentários/química , Agentes de Capeamento da Polpa Dentária e Pulpectomia/toxicidade , Cálcio , Hidróxido de Cálcio/química , Cimentos Dentários/toxicidade , Capeamento da Polpa Dentária , Humanos , Concentração de Íons de Hidrogênio , Cura Luminosa de Adesivos Dentários , Processos Fotoquímicos , Polimerização , Agentes de Capeamento da Polpa Dentária e Pulpectomia/química
15.
Dent Mater ; 36(12): 1508-1515, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32948331

RESUMO

OBJECTIVES: A competing risk (CR) model distinguishing adhesive, cohesive and mixed failures as competing events was used for the analysis of micro-tensile bond strength (µTBS) data and compared with a conventional failure mode non-distinguishing survival model. METHODS: Fifty human molars were bonded using five universal adhesives (n = 10) and subdivided according to aging conditions (24-h water storage, thermocycling). After µTBS to dentin was tested, a fractographic analysis was performed using scanning electron microscopy. Survival analyses of the µTBS data were performed using both a failure mode distinguishing Weibull CR model, and a conventional failure mode non-distinguishing Weibull model. Weibull shape (m) and scale (σθ) parameters were calculated for both models using the maximum likelihood estimation method, and strength at 10 % probability of failure, σ0.10, was estimated. Groups were compared using 95 % confidence intervals. RESULTS: CR-model estimates of σθ and σ0.10 for adhesive failures were higher than those of the conventional model, more markedly in groups with lower percentages of adhesive failures. CR-model strength estimates for cohesive failures were similar in all groups regardless of their bond strengths and failure mode distributions. SIGNIFICANCE: Merging all bond-strength data into one dataset irrespective of the failure mode may result in a severe underestimation of bond strength, especially in groups with low incidence of adhesive failures. Bond-strength data analysis using a CR model could provide more accurate estimates of bond strength, and strength estimates for cohesive failures which were apparently independent of bond strength could serve as an internal validity indicator of the CR model.


Assuntos
Colagem Dentária , Adesivos Dentinários , Resinas Compostas , Análise de Dados , Cimentos Dentários , Dentina , Humanos , Teste de Materiais , Cimentos de Resina , Resistência à Tração
16.
Sci Rep ; 10(1): 15754, 2020 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-32978464

RESUMO

Optical coherence tomography (OCT) can create cross-sectional images of tooth without X-ray exposure. This study aimed to investigate the diagnostic accuracy of 3D imaging of OCT for proximal caries in posterior teeth. Thirty-six human molar teeth with 51 proximal surfaces visibly 6 intact, 16 slightly demineralized, and 29 distinct carious changes were mounted to take digital radiographs and 3D OCT images. The sensitivity, specificity and area under the receiver operating characteristic curve (AUC) for the diagnosis of enamel caries and dentin caries were calculated to quantify the diagnostic ability of 3D OCT in comparison with digital radiography. Diagnostic accuracy was evaluated by the agreement with histology using weighted Kappa. OCT showed significantly higher sensitivity, AUC and Kappa values than radiography. OCT can be a safer option for the diagnosis of proximal caries in posterior teeth that can be applied to the patients without X-ray exposure.


Assuntos
Cárie Dentária/diagnóstico por imagem , Imageamento Tridimensional , Dente Molar/diagnóstico por imagem , Tomografia de Coerência Óptica , Humanos , Sensibilidade e Especificidade
17.
Acta odontol. latinoam ; 33(2): 82-89, Sept. 2020. graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1130737

RESUMO

ABSTRACT The aim of this study was to evaluate the degree of conversion, cytotoxicity, solubility and pH of photopolymerizable calciumbased cements submitted to preheating. The degree of conversion was analyzed by Fourier transform infrared, cytotoxicity by the MTT test and solubility through loss of mass. The data were subjected to statistical tests (ANOVA / Tukey's, p<0.05). The photopolymerizable materials showed a low degree of conversion, regardless of preheating. All materials caused a reduction in cell viability at 24 hours and 7 days, with the Dycal (control) being more cytotoxic. Heat had a positive effect on Biocal at 7 days. Dycal is the most soluble material. Heat had no effect on the solubility or pH of the polymerizable materials. It is concluded that photopolymerizable calcium-based cements have a low degree of conversion and are soluble, which results in mild to moderate cytotoxicity.


RESUMO O objetivo do presente estudo foi avaliar o grau de conversão, citotoxicidade, solubilidade e pH de cimentos à base de cálcio fotopolimerizáveis submetidos a pré-aquecimento. O grau de conversão foi analisado por espectroscopia no infravermelho com transformada de Fourier, a citotoxicidade pelo teste de MTT e a solubilidade através da perda de massa. Os dados foram submetidos a testes estatísticos (ANOVA/Tukey, p<0,05). Os materiais fotopolimerizáveis apresentaram baixo grau de conversão, independente do pré-aquecimento. Todos os materiais causaram redução da viabilidade celular nas análises de 24 horas e 7 dias, sendo que o Dycal (controle) apresentouse mais citotóxico e o calor apresentou efeito positivo sobre o Biocal na análise de 7 dias. O Dycal é o material mais solúvel e o calor não causou efeito na solubilidade e pH dos materiais polimerizáveis. Assim, conclui-se que os cimentos à base de cálcio fotopolimerizáveis apresentam baixo grau de conversão e são solúveis, que resulta em citotoxicidade suave e moderada.

18.
J Prosthet Dent ; 2020 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-32800576

RESUMO

A straightforward technique is presented for an interim or short-term definitive esthetic replacement of missing anterior teeth requiring no tooth preparation. Composite resins are injected into transparent silicone indices fabricated from 3-dimensional-printed casts of a digital waxing. The dentin core is formed of a durable short fiber-reinforced injectable composite resin and veneered with an enamel-shade composite resin for enhanced esthetics. Besides being noninvasive, this technique is more straightforward than traditional options, reducing chair time while providing an accurate outcome.

19.
J Esthet Restor Dent ; 32(7): 638-644, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32603555

RESUMO

OBJECTIVE: Restorative treatment of anterior teeth is often required as the final step of orthodontic therapy to optimize the esthetics and function. This case report presents a direct minimally invasive approach for post-orthodontic recontouring of anterior teeth using the composite injection technique with a digital workflow. CLINICAL CONSIDERATIONS: The extraction of central incisors with short roots was indicated to resolve maxillary anterior crowding. The gained space was closed with lateral incisors, and it was necessary to recontour them and canines to resemble central and lateral incisors, respectively. The restorations were digitally designed, and a transparent silicone index was fabricated from a 3D-printed cast of the digital wax-up. After lateral incisors and canines were bonded with a universal adhesive in the etch-and-rinse mode, a highly filled injectable composite resin was applied into the index. The restorative treatment was preceded by gingivectomy using an Er:YAG laser and home bleaching. CONCLUSIONS: In cases where more complex recontouring of anterior teeth is necessary, the composite injection technique could be a suitable alternative to indirect restorations, because it is straightforward, cost-effective, and does not require any preparation. The digital workflow simplified and expedited the treatment while contributing to its precision. CLINICAL SIGNIFICANCE: Post-orthodontic recontouring using direct composite restorations is well accepted by patients due to low cost and non-invasiveness. However, in complicated cases, the free-hand technique is time-consuming and technique-sensitive. The presented composite injection technique with a digital workflow significantly simplifies and expedites the composite placement while predictably enhancing the treatment outcome.


Assuntos
Restauração Dentária Permanente , Fluxo de Trabalho , Resinas Compostas , Estética Dentária , Humanos , Incisivo
20.
Dent Mater J ; 39(6): 970-975, 2020 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-32611987

RESUMO

To assess, in vitro, the influence of heat air treatment on cytotoxicity and degree of conversion (DC) of universal self-etch adhesives (Ambar Universal APS, Scotchbond Universal Adhesive, and Tetric N-Bond Universal) in an NIH/3T3 fibroblast cell culture. Samples were divided into three groups: 1) no heat treatment (control), 2) 37°C and 3) 60°C heat treatment before photopolymerization. Cytotoxicity was analyzed by MTT assay and the DC by FTIR. All adhesives heated at 60°C showed reduced cytotoxicity levels when compared with those heated at 37°C. In general, DC of Ambar Universal APS presented the highest DC than Scotchbond Universal Adhesive and Tetric N-Bond Universal, and the hot air treatment do not influence the conversion. Heat treatment at 60°C was able to reduce the cytotoxicity of universal self-etch adhesives, even, the heat treatment does not enhances the DC.


Assuntos
Colagem Dentária , Adesivos , Cimentos Dentários , Dentina , Adesivos Dentinários , Temperatura Alta , Teste de Materiais , Polimerização , Cimentos de Resina
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