Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.102
Filtrar
1.
J Appl Oral Sci ; 28: e20190499, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32348441

RESUMO

Enzymatic degradation of the hybrid layer can be accelerated by the activation of dentin metalloproteinases (MMP) during the bonding procedure. MMP inhibitors may be used to contain this process. Objective To evaluate the degree of conversion (DC%), dentin bond strength (µTBS) (immediate and after 1 year of storage in water), and nanoleakage of an experimental (EXP) and a commercial (SB) adhesive system, containing different concentrations of the MMP inhibitor GM1489: 0, 1 µM, 5 µM and 10 µM. Methodology DC% was evaluated by FT-IR spectroscopy. Dentin bond strength was evaluated by µTBS test. Half of beams were submitted to the µTBS test after 24 h and the other half, after storage for 1 year. From each tooth and storage time, 2 beams were reserved for nanoleakage testing. Data were analyzed using ANOVA and Tukey's test to compare means (α=0.05). Results All adhesive systems maintained the µTBS after 1 year of storage. Groups with higher concentrations of inhibitor (5 µM and 10 µM) showed higher µTBS values than groups without inhibitor or with 1 µM. The nanoleakage values of all groups showed no increase after 1 year of storage and values were similar for SB and EXP groups, in both storage periods. The inhibitor did not affect the DC% of the EXP groups, but the SB5 and SB10 groups showed higher DC% values than those of SB0 and SB1. Conclusions The incorporation of GM1489 in the adhesive systems had no detrimental effect on DC%. The concentrations of 5 µM GM1489 for SB and 5 µM or 10 µM for EXP provided higher µTBS than groups without GM1489, in the evaluation after 1 year of storage; whereas the concentration of inhibitor did not affect adhesive systems nanoleakage.


Assuntos
Cimentos Dentários/química , Dentina/química , Inibidores de Metaloproteinases de Matriz/química , Metacrilatos/química , Polietilenoglicóis/química , Ácidos Polimetacrílicos/química , Análise de Variância , Colagem Dentária/métodos , Corrosão Dentária/métodos , Infiltração Dentária , Dentina/efeitos dos fármacos , Humanos , Teste de Materiais , Valores de Referência , Reprodutibilidade dos Testes , Espectroscopia de Infravermelho com Transformada de Fourier , Estatísticas não Paramétricas , Propriedades de Superfície , Resistência à Tração , Fatores de Tempo
2.
Niger J Clin Pract ; 23(1): 110-115, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31929216

RESUMO

Objective: The aim of this study was to compare to effect of phototherapy and surface flattening after immediately bleaching on the shear bond strength to bleached enamel. Methods: Ninety-six human upper incisors were divided into 4 groups (n = 24). Group NB: no bleached, group P: phototherapy with YSGG laser, group F: 0.5 mm surface flattening, group PF: 0.5 mm surface flattening and phototherapy with Er;Cr:YSGG laser. Then, each group was assigned to 2 subgroups according to adhesive mode (n = 12) as; subgroup S (self-etching mode), subgroup T (total-etching mode) which are universal adhesives. All surface conditionings and restorations were performed with composite resin materials immediately after bleaching. Shear bond strength test was performed by using universal testing machine. The surfaces were also evaluated with SEM. The data were statistically analyzed with one-way ANOVA post-hoc Tukey tests. Results: The lowest SBS values were achieved in FS (13.72 ± 2.29) while the highest ones in PT (28.01 ± 6.81). However, the differences were not significant (P > 0.05). All surface conditioning methods provided SBS values similar to the control (P > 0.05). All subgroups of self-etching mode were significantly lower than their total-etching counterparts (P < 0.05). Conclusions: The present study showed that surface removal and phototherapy have a potential clinical application for eliminate to undesirable effect of bleaching treatment. Surface conditioning with either flattening and/or phototherapy may provide clinicians to restore bleached teeth at the same visit with bleaching and reduce chair-time.


Assuntos
Adesivos/farmacologia , Colagem Dentária/métodos , Esmalte Dentário/efeitos dos fármacos , Corrosão Dentária/métodos , Lasers de Estado Sólido/uso terapêutico , Fototerapia , Resistência ao Cisalhamento , Clareamento Dental , Condicionamento Ácido do Dente/métodos , Resinas Compostas/química , Materiais Dentários/química , Humanos , Teste de Materiais , Clareamento Dental/métodos
3.
Niger J Clin Pract ; 22(12): 1758-1764, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31793485

RESUMO

Aim: The aim of this in vitro study was to compare the effects of the application of three different cavity disinfecting agents to dentin on the micro-shear bond strength (µ-SBS) of one self-etch and two universal adhesive systems. Materials and Methods: In total, 120 caries-free human permanent molar teeth were used in this study. Mid-coronal dentin surfaces were revealed by cutting occlusal enamel and a standard smear layer was obtained by using 600-800-1200 grid silicon carbide abrasive papers. Specimens were randomly assigned to four groups according to the disinfectant used: Group 1: Control (no disinfectant); Group 2: 2% chlorhexidine based (Consepsis); Group 3: 10 ppm ozonated water (TeknO3zone); Group 4: 5% boric acid (Handmade). Each group was divided into three subgroups according to the type of adhesive (Clearfil SE Bond, OptiBond XTR, and Tokuyama Universal). Specimens were bonded using either Clearfil SE Bond, OptiBond XTR or Tokuyama Universal, which were employed according to the manufacturer's instructions. Resin composite microcylinders were bonded using Tygon® tubes for µ-SBS testing. After specimens were stored for 24 h, at 37°C in distilled water, µ-SBS test was measured with a universal test machine (LF Plus, Lloyd, Instrument). µ-SBS results were analyzed by one-way analysis of variance (ANOVA) and Tukey's tests. Results: When the mean microshear bond strength values of the control group were compared, the difference between the subgroups was not significant (P < 0.05). When the mean microshear bond strength values of the chx, ozonated water, and boric acid were compared, the difference between Clearfil SE Bond and Tokuyama Universal was significant (P < 0.05) and the difference between the other groups was not significant (P > 0.05). Conclusion: Ozonated water and boric acid may be as an alternative to other materials used as cavity disinfectants.


Assuntos
Ácidos Bóricos , Colagem Dentária/métodos , Cimentos Dentários , Desinfetantes de Equipamento Odontológico/farmacologia , Adesivos Dentinários , Dentina/efeitos dos fármacos , Água , Clorexidina , Resinas Compostas/química , Esmalte Dentário , Corrosão Dentária/métodos , Humanos , Cimentos de Resina/uso terapêutico , Camada de Esfregaço
4.
Niger J Clin Pract ; 22(10): 1441-1447, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31607737

RESUMO

Background: There was no enough data about the appropriate surface cleaning of core composite material after temporary cementation. Aim: To evaluate the effects of surface cleaning techniques on initial shear bond strength (SBS) between core composite material and resin nanoceramic crown materials after temporary cementation. Material and Methods: Cubic specimens were prepared from prosthetic materials, including Lava Ultimate. Cylinder-shaped composites were cemented to glass slides with eugenol-free temporary cement, resulting in a total of 44 cylinders (n = 11). The surfaces of composite cylinders were then cleaned with an Er, Cr:YSGG laser, 37% orthophosphoric acid, yellow tape diamond bur, or dental explorer. Cleaned cylinders were bonded to cubic specimens with resin cement. Initial SBS tests were performed with a universal testing machine at 0.5 mm/min crosshead speed. One-way ANOVA and post hoc Tukey tests were used to analyze the obtained data (P =0.05). Results: Initial SBS values were significantly affected by the different surface cleaning methods (P <.05). The highest SBS value was obtained with the laser group (SBS = 17.14), while the lowest was obtained with dental explorer group (SBS = 5.95). There was no significant difference between the diamond bur group and the laser group (P =0.982). Conclusions: Laser irradiation or yellow tape diamond bur cleaning of the core composite surface could be recommended to strengthen bond strength between the resin luting cement and the core composite. Before adhesive or conventional cementation of prosthetic restoration, the core composite surface should be cleaned.


Assuntos
Colagem Dentária/métodos , Cimentos Dentários/química , Corrosão Dentária/métodos , Adesivos Dentinários/química , Vidro/química , Lasers de Estado Sólido/uso terapêutico , Cimentos de Resina/química , Cimentação , Resinas Compostas/química , Cimentos de Ionômeros de Vidro , Humanos , Teste de Materiais , Resistência ao Cisalhamento , Propriedades de Superfície
5.
Photobiomodul Photomed Laser Surg ; 37(8): 465-472, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31390314

RESUMO

Objective: The purpose of this study was to evaluate the effects of Er,Cr:YSGG laser irradiation with different energy powers versus sandblasting for enhancing the tensile bond strength (TBS) between titanium implant abutments (IAs) and resin cements. Background data: Clinical decementation of prosthetic restorations often occurs, particularly on short IAs. Increasing the bonding area on the IA surface can enhance the function and longevity of the superstructure. Materials and methods: Fifty dental IAs were used in solid form and randomly assigned to five groups (n = 10 each) for the following different pretreatments: control group was left untreated, a laser operating at 2.78 µm wavelength with different energy powers (1, 2, and 3 W) was used for three laser groups, and 50 µm alumina particles were applied to the abutment surface for the sandblasting group. Fifty metal substructures that had an occlusal metal O-ring were cast and cemented to all abutments using dual-cure resin cement. Test specimens were then subjected to thermal cycling. TBS tests were performed with a universal testing machine. The specimens' surface topography and roughness were evaluated with scanning electron microscope, and energy dispersive spectroscopy (EDS) was used to measure the elemental profiles of each specimen. Data were analyzed using a one-way analysis of variance/Kruskal-Wallis test at a significance level of p < 0.05. Results: Surface treatments affected the surface roughness and TBS of the IA. The sandblasting group showed the highest bond strength values (510.77 ± 60.86 N) and followed by the 2 W group (279.07 ± 37.9 N). In EDS analysis, no elemental components other than titanium and oxygen were observed, except for in the sandblasting group. Conclusions: Sandblasting and 2 W laser treatment increased the surface roughness of the IA, which could contribute to the increased interfacial bond strength between the IA and resin cement.


Assuntos
Dente Suporte , Colagem Dentária/métodos , Corrosão Dentária/métodos , Lasers de Estado Sólido , Teste de Materiais , Microscopia Eletrônica de Varredura , Distribuição Aleatória , Cimentos de Resina/química , Espectrometria por Raios X , Propriedades de Superfície , Resistência à Tração , Titânio/química
6.
BMC Oral Health ; 19(1): 178, 2019 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-31387557

RESUMO

BACKGROUND: The aim of this study was to evaluate the effect of universal adhesives (UA) and silane on the microtensile bond strength (µTBS) of resin cement to a hybrid ceramic Vita Enamic (VE). METHODS: VE specimens were acid etched using hydrofluoric acid (HF) and were assigned to three groups (n = 10) based on the applied bonding technique. In group 1 (S), a silane-based primer was used as a surface treatment prior to the application of a resin cement (Variolink Esthetic DC). In group 2, a silane-containing UA, Clearfil Universal Bond (CUB) was used for the surface treatment, and in group 3, A silane-free UA, Tetric N-Bond Universal (TNU) was used for surface treatment. Resin cement build-ups were prepared. The bonded specimens were sectioned into resin-ceramic beams. Half of the beams of each group were stored for 24 h at 37 °C and the other half were subjected to a thermo-cycling aging. The microtensile bond strength (µTBS) was measured at a crosshead speed of 0.5 mm/min. Failure modes were assessed accordingly. Data were analyzed using a) two-way analysis of variance ANOVA followed by one-way ANOVA and Tukey tests between groups and b) independent t-test to detect differences (α = 0.05) for each group. The surface topographies of the ceramic surface were evaluated using scanning electron microscopy. RESULTS: The results showed that silane-based primer (S) application resulted in significantly higher (p < 0.05) µTBS values after 24 h and after thermocycling compared to both silane-containing UA (CUB) and silane-free UA (TNU). The µTBS values of all groups were significantly reduced after thermocycling. No statistically significant difference was observed between the µTBS of CUB and TNU after 24 h. However, TNU showed significantly higher µTBS after thermocycling. Different failure modes were observed, and adhesive failure was the most common in all groups. Marked surface topographic changes were observed following HF etching. CONCLUSION: It is concluded that, the UAs tested cannot be recommended as substitutes to the silanization of Hybrid ceramic.


Assuntos
Cerâmica/química , Colagem Dentária , Cimentos de Resina/química , Condicionamento Ácido do Dente , Cimentos Dentários , Corrosão Dentária/métodos , Porcelana Dentária/química , Análise do Estresse Dentário , Estética Dentária , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Propriedades de Superfície , Resistência à Tração
7.
Microsc Res Tech ; 82(10): 1668-1680, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31259458

RESUMO

The study aimed at finding an optimal combination of acid concentration and etching time when nitric acid is used as etchant for the study of the finer details of human dental enamel structure. Four hundred 2-3-mm-thick segments of facio-lingually sectioned human third molar crowns were assigned to 20 groups with 20 specimens in each group, each group differing with respect to acid concentration (0.1, 1, 2.5, and 5%) and etching time (15, 30, 45, 90, and 180 s). After etching and preparation, specimens were observed in the scanning electron microscope (SEM). Surface roughness/topography increased with increasing acid concentration and increasing etching time, but not in a linear fashion; generally, prisms tended to go from flat-surfaced to cone-shaped and prism sheaths from fissure-like to wedge-shaped. Intragroup variations and intergroup similarities were considerable. The two major enamel factors determining the etch effect are crystal orientation and prism sheath properties. Other factors, such as distribution of porosities and crystal quality, also contribute probably. Slight to moderate topography is best for observing the finer enamel structure, for example, etching with concentrations in the range 0.1-1% and with etching times in the range 15-90 s, the stronger the acid, the shorter the time. The depth effect of nitric acid is judged to be relatively small. Considerable variations in expression of prism cross-striations were observed. SEM observations of acid-etched enamel in carefully selected planes are a powerful method for the study of enamel structure, bearing in mind the artifactual aspects of the observed surface.


Assuntos
Ácidos/metabolismo , Esmalte Dentário/ultraestrutura , Corrosão Dentária/métodos , Humanos , Microscopia Eletrônica de Varredura , Dente Molar/ultraestrutura , Propriedades de Superfície , Fatores de Tempo
8.
Photobiomodul Photomed Laser Surg ; 37(7): 434-441, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31265377

RESUMO

Objective: The purpose of this study is to investigate the effect of various presintering and sintered surface treatments and thermocycling on the bond strength between zirconia and veneer ceramics. Background data: Bond stability between zirconia and veneer ceramic is a major concern, and only limited evidence about its longevity is currently available. Moreover, no study has yet evaluated the influence of thermocycling on the bond strength of veneer ceramic to zirconia after Er,Cr:YSGG laser irradiation at different pulse durations and sandblasting. Materials and methods: In this study, 220 nonsintered zirconia specimens were prepared with CAD/CAM and randomly divided into 2 groups; half of the specimens in each group were stored in water for 1 week, and the other half were thermocycled (5000 cycles) between baths of 5°C and 55°C. Specimens were then divided into five subgroups based on the following surface treatments: control (untreated surface), sandblasting (120 µm Al2O3), and Er,Cr: YSGG laser irradiations (3 W-8 Hz, 3 W-15 Hz, and 3 W-20 Hz, MGG 6 laser tip, for 20 sec, distance of 10 mm, water/airflow of 55% and 65%). Morphological assessment was done using atomic force microscopy and scanning electron microscopy, and phase transformation was assessed by X-ray diffractometry. All specimens were then veneered with veneering ceramic, and bond strength test using a universal testing device at a 1 mm/min crosshead speed. Data were evaluated by Kruskal-Wallis variance analysis and the Mann-Whitney U test. Results: There was no significant difference in the bonding strength values among the (p > 0.05). Thermocycling reduced the bond strength, but it was not significant (p > 0.05), except for the presintering 20 Hz group (p < 0.02). Conclusions: Application of thermocycling to sintered zirconia specimens may be detrimental to the shear bond strength of zirconia ceramics. Treating the zirconia surface after sintering is not recommended, due to the decrease in bond strength.


Assuntos
Cerâmica/química , Colagem Dentária/métodos , Corrosão Dentária/métodos , Materiais Dentários/química , Lasers de Estado Sólido , Resistência ao Cisalhamento/efeitos da radiação , Zircônio/química , Desenho Assistido por Computador , Facetas Dentárias , Teste de Materiais , Microscopia Eletrônica de Varredura , Propriedades de Superfície
9.
Photobiomodul Photomed Laser Surg ; 37(7): 428-433, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31265378

RESUMO

Objective: Evaluate the bond strength of repairs made on composite resin following the treatment of the surface of the flaw with different bonding agents and/or CO2 laser. Background: The influence of CO2 laser and its interaction with other bonding agents on the surface of the flaw is not yet known. In this study, CO2 laser was chosen to treat the surface of the flaw due to its capacity to promote irregularities on the surface that enhance mechanical micro-retention. Methods: A block was created with Vitra APS nanohybrid composite resin (color: A3; FGM, Joinville, Brazil) measuring 5 mm in width, length, and depth (volume: 125 mm3). The surface of the flaw was treated before the repair with an adhesive, silane bonding agent, and/or CO2 laser. Six specimens were created in composite resin for each group (total: n = 36): G1: resin+resin; G2: adhesive+resin; G3: laser+adhesive; G4: laser+silane+adhesive; G5: silane+adhesive; G6: laser+silane. After the repair, the surfaces of the fracture of all specimens, which were submitted to the microtraction test, were analyzed under an optical microscope. Bond strength values obtained according to the type of surface treatment were tabulated and submitted to the Kruskal-Wallis test. Dunn's test was used to compare means. Results: G3 and G4 had significantly higher bond strength values compared to all other groups tested. Adhesive fractures predominated in all groups. However, G3 and G4 had a higher percentage of cohesive fractures compared to the other groups. Conclusions: The application of CO2 laser as a surface treatment led to greater bond strength of composite resin repairs in comparison with the groups that only received treatment with a burr and silanization. The groups submitted to CO2 laser also had a significantly lower number of adhesive failures when submitted to the microtraction test.


Assuntos
Resinas Compostas/química , Colagem Dentária , Esmalte Dentário/efeitos da radiação , Corrosão Dentária/métodos , Materiais Dentários/química , Lasers de Gás , Dióxido de Carbono , Análise do Estresse Dentário , Adesivos Dentinários/química , Teste de Materiais , Resistência ao Cisalhamento/efeitos da radiação , Estresse Mecânico , Propriedades de Superfície
10.
Photobiomodul Photomed Laser Surg ; 37(7): 442-450, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31265379

RESUMO

Objective: This study compared the effects of different surface treatments on the surface roughness (Ra), and shear bond strength (SBS) of resin cement to yttria-stabilized tetragonal zirconia (Y-TZP) ceramic and nickel-chromium (Ni-Cr) base metal alloy, respectively. Materials and methods: Thirty disk-shaped specimens (3 mm height and 10 mm diameter) of each material (Y-TZP and Ni-Cr) were prepared. Both zirconia and metal specimens were randomly assigned to three equal groups, according to the surface treatments (n = 10): sandblasting, sandblasting + Er:YAG laser, and sandblasting + Nd:YAG laser. Resin cement cylinders (4 mm diameter and 3 mm thickness) were placed on each specimen. The SBS tests were performed at a 1 mm per minute crosshead speed through a knife-edge rod after 5000 thermal cycles. The Ra (µm) of the specimens was measured using a profilometer and evaluated topographically by atomic force microscopy and scanning electron microscopy. Analysis of variance, followed by Tukey's honestly significant difference, in addition to the Kruskal-Wallis test, followed by the Mann-Whitney U test, were used for statistical analysis (α = 0.05). Results: Combined sandblasting and laser treatment of the metal groups led to statistically higher Ra values than sandblasting alone (p < 0.05). For Y-TZP, there were no significant differences between the Ra values of the subgroups (p > 0.05). The SBS of the sandblasted metal group was significantly higher than the other two laser-irradiated groups, whereas the SBS of sandblasted zirconia was only significantly higher than the Nd:YAG laser-irradiated group (p < 0.05). Conclusions: Combined laser and sandblasting surface treatments resulted in rougher surfaces than sandblasting alone, especially for the metal specimens. Sandblasting, alone, improved the SBS of resin cement in both metal and zirconia, compared with the laser and sandblasting treatments, combined.


Assuntos
Ligas de Cromo/química , Ligas Dentárias/química , Colagem Dentária/métodos , Corrosão Dentária/métodos , Porcelana Dentária/química , Lasers de Estado Sólido , Cimentos de Resina/química , Ítrio/química , Zircônio/química , Teste de Materiais , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Resistência ao Cisalhamento/efeitos da radiação , Propriedades de Superfície
11.
Photobiomodul Photomed Laser Surg ; 37(8): 483-488, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31081712

RESUMO

Objective: The aim of this study was to assess the effect of Er;Cr:YSGG laser parameters (power and frequency) on the bond strength and color stability of lithium disilicate (LD) ceramics. Materials and methods: One hundred ten specimens of LD ceramic were fabricated following heat pressed technique. Fifty disks were randomly distributed into five groups according to types of surface treatment [hydrofluoric (HF) acid, L1S L2S, L1D, and L2D]. For all laser-treated groups, bond preparation settings were used with a gold hand piece using a MZ10 tip (Er;Cr:YSGG, water lase I plus; Biolase). After surface treatment, adhesive bond was applied, and after photopolymerization, a composite buildup was performed. To evaluate shear bond strength, a controlled force was applied until failure using a universal testing machine. Color stability was assessed for six groups (HF, L1S L2S, L1D, L2D, and control) of LD ceramic (shade A1, LT translucency) through the CIE L*a*b* system. Three specimens from each of the six groups were selected randomly for assessment of surface topography using scanning electron microscopy. Means and standard deviations were compared using analysis of variance and Tukey's post hoc test (p < 0.05). Results: The maximum and minimum mean bond strength were shown by the L2D group 19.95 ± 1.014 and L1S group specimens 14.68 ± 0.863, respectively. Highest mean ΔE was found in L2S group 8.17 ± 2.10 and the lowest mean ΔE was found in control group (no treatment) 0.11 ± 0.05. Conclusions: LD specimens lased (Er;Cr:YSGG) with 3.75 W power and 15 Hz frequency for 4 min showed bond strength comparable with HF acid samples, and color changes within acceptable range (ΔE 1.17). Laser treatment (Er;Cr:YSGG) at 3.75 W power and 15 Hz frequency for 4 min of LD ceramics appears to be clinically efficient, showing acceptable bond strength and color stability.


Assuntos
Cerâmica/química , Colagem Dentária/métodos , Corrosão Dentária/métodos , Porcelana Dentária/química , Lasers de Estado Sólido , Cor , Análise do Estresse Dentário , Ácido Fluorídrico , Técnicas In Vitro , Microscopia Eletrônica de Varredura , Resistência ao Cisalhamento , Propriedades de Superfície
12.
Photobiomodul Photomed Laser Surg ; 37(8): 473-482, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31081715

RESUMO

Objective and background: Different surface treatments have been tested in composite repair studies. However, there is still no consensus on the most effective repair protocol. The aim of this study is to measure the roughness values of eight different surface treatments for the repair procedure, to examine the effect of each surface treatment and three different composites on the repair bond strength with and without silane, and to evaluate whether there is a correlation between bond strength and roughness. Methods: The blocks were prepared with Filtek Z550 (3M ESPE) for the roughness measurements and divided into eight groups according to surface treatments. The roughness values of the surface treatments were measured by a 3D scanning contact profilometer (Nanomap LS). For the shear test, further samples were prepared, aged, and divided into three subgroups for the repair procedure with Filtek Z550 (3M ESPE), Vertise Flow (Kerr, USA), and G-aenial Flo (GC, Japan) after the surface treatments. Then, the shear test was performed. The Kruskal-Wallis and Spearman's Correlation tests were used for statistical evaluation of the data. Results: Significant differences were found between surface treatments and composite resins in terms of bond strength (p < 0.05). There is no correlation between the roughness and bond strength values. Conclusions: In bond strength, surface topography is more important than the numerical value of roughness. In the repair of composite restorations, methods that are already in clinical practice and more practical can be used instead of methods that require additional costs and devices.


Assuntos
Resinas Compostas/química , Colagem Dentária/métodos , Corrosão Dentária/métodos , Lasers de Estado Sólido , Adesivos Dentinários , Teste de Materiais , Cimentos de Resina , Resistência ao Cisalhamento/efeitos da radiação , Silanos/química , Propriedades de Superfície
13.
Clin Oral Investig ; 23(12): 4345-4353, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30953165

RESUMO

OBJECTIVES: To evaluate the critical bond strength (σ) of ceramic and metal brackets to a lithium disilicate-based glass-ceramic. MATERIALS AND METHODS: Two hundred and forty ceramic specimens (IPS e-max CAD) were randomly distributed in 12 experimental groups (n = 20). Two ceramic brackets (monocrystalline, BCm; and polycrystalline, BCp) and a metal bracket (BM) were bonded to glass-ceramic specimens after one of the following surface treatments: HF-hydrofluoric acid applied for 60 s; S-silane applied for 3 min; HFS-HF followed by S; and MDP-application of an adhesive containing a phosphate monomer (MDP). All brackets were bonded to the treated glass-ceramic using a resin cement, stored in 37 °C water for 48 h before shear bond strength testing. Optical (OM) and scanning electron (SEM) microscopies were used for fractographic analysis. Data was statistically analyzed using Kruskal-Wallis and Student-Newman-Keuls (α = 0.05). RESULTS: BCm bonded to glass-ceramic treated with either HFS or HF showed the highest median σ values, respectively, 10.5 MPa and 8.5 MPa. In contrast, the BCp bonded to glass-ceramic treated with MDP showed the lowest median σ value (0.8 MPa), which was not statistically different from other MDP-treated groups. CONCLUSIONS: The failure mode was governed by the glass-ceramic surface treatment, not by the bracket type. Quantitative (σ values) and qualitative (fracture mode) data suggested a minimum of 5 MPa for brackets bonded to glass-ceramic, which is the lower critical limit bond strength for a comprehensive orthodontic treatment. CLINICAL RELEVANCE: Bonding brackets to glass-ceramic requires micromechanical retention.


Assuntos
Cerâmica/química , Colagem Dentária , Corrosão Dentária/métodos , Teste de Materiais/métodos , Braquetes Ortodônticos , Análise do Estresse Dentário , Humanos , Microscopia Eletrônica de Varredura , Cimentos de Resina/química , Resistência ao Cisalhamento , Propriedades de Superfície
14.
J Appl Oral Sci ; 27: e20180358, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30994773

RESUMO

OBJECTIVE: The aim of this randomized, controlled, prospective clinical trial was to evaluate the performances of two different universal adhesives and one etch-rinse adhesive for restoration of non-carious cervical lesions (NCCLs). MATERIAL AND METHODS: Twenty patients with at least seven NCCLs were enrolled. Lesions were divided into seven groups according to adhesive systems and application modes: GSE: GLUMA Universal-self-etch, GSL: GLUMA Universal-selective etching, GER: GLUMA Universal-etch-and-rinse, ASE: All-Bond Universal-self-etch, ASL: All-Bond Universal-selective etching, AER: All-Bond Universal-etch-and-rinse, SBE (Control): Single Bond2-etch-and-rinse. A total of 155 NCCLs were restored with a nano hybrid composite (Tetric N-Ceram). Restorations were scored with regard to retention, marginal discoloration, marginal adaptation, recurrent caries and post-operative sensitivity using modified United States Public Health Service (USPHS) criteria after one week, 6, 12 and 24 months. Statistical evaluations were performed using Chi-square tests (p=0.05). RESULTS: The recall rate was 81.9% after the 24-month follow-up. The cumulative retention rates for self-etch groups (GSE: 72.2%, ASE:75%) were significantly lower than other experimental groups (GSL: 93.7%, GER: 100%, ASL: 94.1%, AER: 100%, SBE: 100%) at the 24-month follow-up (p<0.05). Regarding marginal adaptation and marginal discoloration, GSE and ASE groups demonstrated more bravo scores after 6 and 12-month observations but differences were not significant (p>0.05). Only one restoration from ASL group demonstrated post-operative sensitivity at 6 and 12-month observations. No secondary caries was observed on the restorations at any recall. At the end of 24-month observations, no significant differences were detected among groups regarding any of the criteria assessed, except retention. CONCLUSION: GLUMA Universal and All-Bond Universal showed better results in etch-and-rinse and selective etching mode compared to the self-etch mode regarding retention. Etch-and-rinse and selective etching application modes of the current universal adhesives tended to provide better clinical outcomes considering the criteria evaluated at the end of 24-month evaluation.


Assuntos
Bis-Fenol A-Glicidil Metacrilato/uso terapêutico , Resinas Compostas/uso terapêutico , Cárie Dentária/terapia , Corrosão Dentária/métodos , Restauração Dentária Permanente/métodos , Glutaral/uso terapêutico , Metacrilatos/uso terapêutico , Ácidos Polimetacrílicos/uso terapêutico , Adulto , Distribuição por Idade , Adaptação Marginal Dentária , Falha de Restauração Dentária , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reprodutibilidade dos Testes , Distribuição por Sexo , Fatores de Tempo , Resultado do Tratamento
15.
Pesqui. bras. odontopediatria clín. integr ; 19(1): 4546, 01 Fevereiro 2019. tab, ilus
Artigo em Inglês | LILACS, BBO - Odontologia | ID: biblio-998216

RESUMO

Objective: To assess the levels of nickel and chromium ions in hair and Gingival Crevicular Fluid (GCF) of orthodontic patients and to evaluate the corrosion of orthodontic bracket surfaces. Material and Methods: Nickel and chromium ion concentrations were measured in hair and GCF of 15 patients (9 females and 6 males, aged 16-28 years old) who had fixed orthodontic treatment using atomic absorption spectroscopy. The samples were taken before treatment (baseline), 4, 8, and 16 months later during treatment. Along with ionic sampling, microscopic sampling was done. One of each patient brackets was removed to get 15 brackets per group. Five brackets were taken randomly from each group to be examined under scanning electron microscope (SEM). Data obtained were analyzed using paired t-tests. Results: After 16 months, compared with the baseline, average hair nickel level changed from 0.125 µg/g to 0.956 µg/g with statistically significant difference (p=0.00); average chromium level changed from 0.090 µg/g to 0.295 µg/g but no significant difference (p>0.05); average GCF nickel level changed from 3.335 µg/g to 10.410 µg/g; average chromium level changed from 1.859 µg/g to 9.818 µg/g. Both of these increases were significant (p=0.000). SEM examinations showed that the corrosion on brackets was seen in the fourth month, and more severely visible after 8 and 16 months of uses. Conclusion: After 16 months of treatment, compared with the baseline, the hair nickel level was increased by 7.7 times; while for chromium was by 3.3 times. Gingival crevicular fluid nickel level was increased by 3.1 times and chromium level was by 5.3 times. The longer time of treatment, the more ions released and the more corrosion of brackets will be.


Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto , Ortodontia , Estudos Longitudinais , Cromo , Corrosão Dentária/métodos , Níquel , Indonésia , Íons
16.
J Prosthodont Res ; 63(1): 52-57, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30220621

RESUMO

PURPOSE: The mechanical properties of polyetheretherketone (PEEK) are ideally suited for fixed dental prostheses. However, PEEK typically has low adhesion strength to resin-based luting agent. This study assessed the shear bond strength between laser groove treated PEEK and resin-based luting agent. METHODS: A total of 230 specimens were randomly divided into five groups (n=46): no-treatment, air abrasion treatment, 100µm-deep, 150µm-deep, and 200µm-deep laser groove treatments. The surface roughness was measured, scanning electron microscopy was used to observe the specimen surfaces, and X-ray photoelectron spectroscopy (XPS) was used to analyze the surfaces. Each group was divided into four resin-based luting agent subgroups: Panavia V5, RelyX Ultimate Resin Cement, G-CEM Link Force, and Super-Bond C&B. After the resin-based luting agent was bonded to the specimens, the bond strength was measured using shear tests and the failure modes were assessed by stereomicroscopy. The surfaces were also observed by scanning electron microscopy (SEM) after the shear bond strength measurements. The data were statistically analyzed using a two-way analysis of variance and Tukey's honest significant difference test (α=0.05). RESULTS: The PEEK surface after laser groove treatment groups exhibited the highest mean Ra values. In the XPS analysis, the laser treated PEEK surface exhibited an effective surface composition for bonding with resin-based luting agent. The shear bond strengths for the laser groove treated samples were significantly higher (p<0.05) than those of the no-treatment and air abrasion treatment groups. CONCLUSIONS: The shear bond strength between PEEK and resin-based luting agent was substantially improved by laser groove treatment.


Assuntos
Colagem Dentária , Cimentos Dentários , Corrosão Dentária/métodos , Cetonas , Lasers , Polietilenoglicóis , Resinas Sintéticas , Resistência ao Cisalhamento , Prótese Dentária , Análise do Estresse Dentário , Teste de Materiais , Microscopia Eletrônica de Varredura , Espectroscopia Fotoeletrônica , Propriedades de Superfície
17.
J Prosthodont ; 28(2): e485-e490, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29430807

RESUMO

PURPOSE: To investigate the effect of sandblasting powder particles on microtensile bond strength (µTBS) of dual-cure adhesive cement to CAD/CAM blocks. MATERIALS AND METHODS: CAD/CAM blocks (Cerasmart, VITA, and LAVA) were cut in slabs and divided into groups: group 1, no sandblasting; group 2, sandblasted with 27-µm Al2 O3 ; group 3, sandblasted with 30-µm CoJet; group 4, sandblasted with 50-µm Al2 O3 . After sandblasting, all specimens were silanized and luted using dual-cure adhesive cement (G-CEM LinkForce). After 24 hours, bonded specimens were cut into 1 ± 0.2 mm2 sticks, and µTBS values were obtained (N = 30). Additionally, 132 CAD/CAM block sections were prepared for surface roughness testing and scanning electron microscopy (SEM) evaluations. Results were analyzed using Kruskal-Wallis One-way ANOVA and Dunn's Post Hoc Test (p < 0.05). RESULTS: Group 1 exhibited significantly lower µTBS than the other groups (p < 0.05). The highest bond strength values were obtained from group 4 (p > 0.05). For LAVA, µTBS values of specimens that were sandblasted with 50-µm Al2 O3 powder were significantly higher than 30-µm-SiO2 and 27-µm Al2 O3 (p < 0.05). CONCLUSIONS: The sand particles investigated (27-µm Al2 O3 , 30-µm SiO2 , or 50-µm Al2 O3 ) did not significantly affect µTBS results of CAD/CAM blocks for Cerasmart and VITA, although the results changed significantly for LAVA. The ideal bond protocol for CAD/CAM blocks is specific to the material used.


Assuntos
Cerâmica/química , Desenho Assistido por Computador , Corrosão Dentária/métodos , Materiais Dentários/química , Cimentos de Resina/química , Análise do Estresse Dentário , Teste de Materiais , Microscopia Eletrônica de Varredura , Pós/química , Dióxido de Silício/química , Propriedades de Superfície , Resistência à Tração
18.
J Prosthodont ; 28(1): e181-e185, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28257161

RESUMO

PURPOSE: In clinical prosthetics procedures, including endodontics and post fixation, the presence of a smear layer can reduce the post bond strength. An Er,Cr:YSGG laser, which emits at 2780 nm, can promote a smear-layer-free surface due to the ablation process. Considering these aspects, the purpose of this work was to evaluate the influence of Er,Cr:YSGG laser irradiation using either a radial or an axial fiber tip on the bond strength of three resin cements to the fiber-reinforced composite posts. MATERIALS AND METHODS: Ninety recently extracted single rooted human teeth had their root canal instrumented and were randomly distributed into nine experimental groups, in which three resin cements (total-etching Variolink II, self-etching Panavia F, and self-adhesive RelyX Unicem Aplicap) and three root canal treatments (no treatment, laser irradiation using the radial fiber tip, laser irradiation using the axial fiber tip) were used. Specimens were then sectioned into three sections (cervical, middle, and apical thirds) with two slices on each section. A push-out test was performed on each slice, and the values were recorded as MPa. The push-out data were analyzed by a Ryan-Joiner normality test followed by a two-way ANOVA test and Tukey pairwise comparison. The statistical analysis was performed on each third section separately, with a 5% significance level. RESULTS: Laser irradiation with axial fiber tip significantly increased the post bond strength of RelyX Unicem Aplicap on middle third of specimens (p < 0.001) when compared to other root canal treatments (unlased or irradiated with radial tip). Considering the Panavia resin cement, laser irradiation with either axial or radial tips promoted a significant increase on the post bond strength of middle third when compared to unlased specimens (p < 0.001); however, laser irradiation did not influence the post bond strength of Variolink resin cement. CONCLUSIONS: The use of the Er,Cr:YSGG laser for clinical prosthetics procedures enhances the post bond strength of Panavia and RelyX Unicem Aplicap resin cements, mainly at middle third of roots, and does not interfere with the bond strength of Variolink resin cement. For the RelyX Unicem Aplicap system, the use of axial tip is most advantageous and can be recommended for future clinical application.


Assuntos
Colagem Dentária/métodos , Lasers de Estado Sólido/uso terapêutico , Cimentos de Resina/química , Cimentos de Resina/efeitos da radiação , Tratamento do Canal Radicular/instrumentação , Tratamento do Canal Radicular/métodos , Raiz Dentária/efeitos da radiação , Corrosão Dentária/métodos , Cavidade Pulpar/efeitos da radiação , Análise do Estresse Dentário , Vidro , Humanos , Teste de Materiais , Técnica para Retentor Intrarradicular/instrumentação , Doses de Radiação , Preparo de Canal Radicular/instrumentação , Preparo de Canal Radicular/métodos , Autocura de Resinas Dentárias , Estresse Mecânico
19.
J Contemp Dent Pract ; 19(10): 1246-1253, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30498181

RESUMO

AIM: The purpose of this study was to investigate the effect of Erbium-doped yttrium aluminium garnet laser laser (Er: YAG laser), sandblast and several universal bonding on the shear bond strength of zirconia ceramic to composite resin. MATERIALS AND METHODS: In this experimental study, 96 Y-TZP disks were used. They were divided into six groups based on surface preparation: 1-Er: YAG laser + single bond universal/ 3M, 2-Er: YAG laser + all bond universal/bisco, 3-Er: YAG laser + G-premio bond/GC, 4-sandblast + single bond universal/3M, 5-sandblast + all bond universal/bisco, 6-sandblast + G-Premio bond/GC; in the next step, composite discs were cured on the surface of the zirconia discs and their shear bond strength was evaluated using a mechanical test machine (universal testing machine). RESULTS: Two-way ANOVA showed that the surface preparation had a significant statistical effect on shear bond strength (p< 0.001). There was no association between these two variables with regards to the interaction of bonding and surface preparation (p = 0.064). Tukey's test showed that the shear bond strengths in the sandblast type group did not differ significantly between the groups according to the type of universal bonding, as well as in the Er: YAG laser treated group by type Universal bonding which was not significantly different between the groups of single bond universal and all bond universal, but there was a significant difference between the groups in terms of single bond universal and G-Premio, as well as all bond universal and G-Premio. CONCLUSION: Based on the results, the preparation of Er:YAG laser is a more appropriate method for increasing bond strength when compared with sandblasting, and among the universal bonding, G-Premio is also more suitable for this purpose. CLINICAL SIGNIFICANCE: The present data indicate that bond strength of laser preparation and G-Premio adhesive might be reliable for clinical application Keywords: Er: YAG Laser, Sandblasting, Shear bond strength, Universal bonding.


Assuntos
Resinas Acrílicas , Cerâmica , Resinas Compostas , Colagem Dentária , Corrosão Dentária/métodos , Materiais Dentários , Lasers de Estado Sólido , Teste de Materiais , Poliuretanos , Resistência ao Cisalhamento , Zircônio , Propriedades de Superfície
20.
BMC Oral Health ; 18(1): 222, 2018 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-30567536

RESUMO

BACKGROUND: The aim of this study was to analyze the surface roughness of yttrium stabilized tetragonal polycrystalline zirconia (Y-TZP) ceramics after different laser treatments (CO2, ER: YAG). METHODS: 5x5x2 mm rectangular prisms of forty eight Y-TZP (Zirkonzahn) ceramic specimens were prepared. In order to standardize surfaces, 600-, 1200- grid silicon carbide papers were used to gradually ground wet on 300 rpm grinding machine for 10 s. Eight groups (n = 6) were randomly formed from the specimens of each ceramic as control (GroupC), sandblasted (GroupS), two different CO2 laser treatments (Group3W: 3 W and 382 w/cal, Group4W: 4 W and 509w/cal) and four different Er: YAG laser treatments (Group150SP: 150 mJ and 10-Hz with 100µS; Group150SSP: 150 mJ and 10-Hz with 300µS; Group300SP: 300 mJ and 10-Hz with 100µS; Group300SSP: 300 mJ and 10-Hz with 300µS). A profilometer was used to conduct surface roughness measurements (Ra). Surface morphologies of the specimens were evaluated under SEM after laser treatment. RESULTS: To analyze the data one-way ANOVA and to compare the mean values Tukey HSD tests (α = .05) were used. One - way ANOVA results showed that Group S had the highest Ra value and Group150 SP had the lowest. After sandblasting group the highest value was seen in Group4W. There were no statistically significant differences among Group C, Group3W, Group150SSP, Group300SP, and Group300SSP. CONCLUSIONS: The study showed that surface roughness of zirconium oxide ceramics was increased with CO2 laser.


Assuntos
Materiais Dentários , Lasers , Ítrio , Zircônio , Corrosão Dentária/métodos , Humanos , Lasers de Gás , Lasers de Estado Sólido , Propriedades de Superfície
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA