RESUMO
Background: The aim of this study was threefold. Firstly, it aimed to introduce and detail a novel method for chemically etching the bases of stainless-steel orthodontic brackets. Secondly, the study sought to investigate the structural alterations within the brackets' microstructure following chemical etching compared to those with sandblasted bases, using electron microscopy analysis. Lastly, the study aimed to evaluate and compare the long-term durability and survivability of orthodontic brackets with chemically etched bases versus those with sandblasted bases, both bonded using the conventional acid etch technique with Transbond XT adhesive, over an 18-month follow-up period. Methods: The study was a randomized clinical control trial with triple blinding and split-mouth study design and consisted of two groups. The brackets in the sandblasted group were prepared by sandblasting the intaglio surface of the base of the bracket with 50 µm SiO2 particles. Hydrofluoric acid was used to roughen the base in the acid-etched group. The bases of the brackets were viewed under an electron microscope to analyze the topographical changes. Results: A total of 5,803 brackets (3,006 acid-etch, 2,797 sandblasted) in 310 patients were bonded, in a split-mouth design by the same operator. The patients were followed for 18 months. The failure rate of 2.59% and 2.7% was noted in an acid-etched and sandblasted group, respectively. There was a close approximation of curves in the Kaplan-Meier plot, and the survival distribution of the two groups in the log-rank (Mantel-Cox) test was insignificant; x2 = 0.062 (P value = 0.804). Conclusion: Acid etching if the bases of the brackets can be used as an alternative to sandblasting furthermore acid etching can be performed on the chair side.
Assuntos
Condicionamento Ácido do Dente , Colagem Dentária , Microscopia Eletrônica de Varredura , Braquetes Ortodônticos , Humanos , Condicionamento Ácido do Dente/métodos , Feminino , Masculino , Colagem Dentária/métodos , Adolescente , Propriedades de Superfície , Adulto , Cimentos de Resina/química , Adulto Jovem , Aço Inoxidável/química , Corrosão Dentária/métodosRESUMO
PURPOSE: To evaluate the effect of sandblasting on the microtensile strength between sclerotic dentin and resin composite. METHODS: 32 premolars with noncarious cervical lesions (NCCLs) were collected, and the teeth were randomly assigned to the control group (C group) and the sandblasted group (S group). Teeth in the S group were sandblasted with 110 µm Al2O3 particles at a pressure of 75 psi, while those in the C group received no further treatment. The characteristics of the tooth surface were observed by scanning electron microscopy (SEM), and the relative area of open dentin tubules (OTs) was calculated by IPP6.0 software. Surface roughness (Ra) was also assessed. The noncarious cervical lesions of all teeth were restored with a resin composite and subsequently sectioned into sticks to measure the microtensile bond strength (µTBS). RESULTS: The mean ± SD µTBS (in MPa) of the sandblasted group was 17.9 ± 0.69 and 14.23 ± 0.44 in the control group (P< 0.05). The relative area of OTs at the gingival wall of the sandblasted group was 69.74 ± 5.23%, and 47.24 ± 7.67% in the control group (P< 0.05). The average surface roughness (µm) was 1.01 ± 0.05 in the sandblasted group and 0.16 ± 0.03 in the control group. Sandblasting could increase the bond strength of sclerotic dentin and resin restorations. CLINICAL SIGNIFICANCE: After sandblasting, the microtensile strength of sclerotic dentin on the surface of noncarious cervical lesions increased, prolonging the resin adhesion longevity. Sandblasting could also alleviate the pain of patients during the treatment process and achieve a minimally invasive treatment.
Assuntos
Resinas Compostas , Colagem Dentária , Dentina , Microscopia Eletrônica de Varredura , Propriedades de Superfície , Resistência à Tração , Humanos , Resinas Compostas/química , Colagem Dentária/métodos , Colo do Dente/patologia , Dente Pré-Molar , Análise do Estresse Dentário , Corrosão Dentária/métodos , Técnicas In VitroRESUMO
OBJECTIVES: The purpose of this study is to evaluate the bond strength of different computer-aided design / computer-aided manufacturing (CAD/CAM) hybrid ceramic materials following different pretreatments. METHODS: A total of 306 CAD/CAM hybrid material specimens were manufactured, n = 102 for each material (VarseoSmile Crownplus [VSCP] by 3D-printing; Vita Enamic [VE] and Grandio Blocs [GB] by milling). Each material was randomly divided into six groups regarding different pretreatment strategies: control, silane, sandblasting (50 µm aluminum oxide particles), sandblasting + silane, etching (9% hydrofluorics acid), etching + silane. Subsequently, surface roughness (Ra) values, surface free energy (SFE) were measured. Each specimen was bonded with a dual-cured adhesive composite. Half of the specimens were subjected to thermocycling (5000 cycles, 5-55 °C). The shear bond strength (SBS) test was performed. Data were analyzed by using a two-way analysis of variance, independent t-test, and Mann-Whitney-U-test (α = 0.05). RESULTS: Material type (p = 0.001), pretreatment strategy (p < 0.001), and the interaction (p < 0.001) all had significant effects on Ra value. However, only etching on VSCP and VE surface increased SFE value significantly. Regarding SBS value, no significant difference was found among the three materials (p = 0.937), while the pretreatment strategy significantly influenced SBS (p < 0.05). Etching on VSCP specimens showed the lowest mean value among all groups, while sandblasting and silane result in higher SBS for all test materials. CONCLUSIONS: The bond strength of CAD/CAM hybrid ceramic materials for milling and 3D-printing was comparable. Sandblasting and silane coupling were suitable for both millable and printable materials, while hydrofluoric etching should not be recommended for CAD/CAM hybrid ceramic materials. CLINICAL RELEVANCE: Since comparable evidence between 3D-printable and millable CAD/CAM dental hybrid materials is scarce, the present study gives clear guidance for pretreatment planning on different materials.
Assuntos
Desenho Assistido por Computador , Coroas , Colagem Dentária , Análise do Estresse Dentário , Teste de Materiais , Resistência ao Cisalhamento , Propriedades de Superfície , Colagem Dentária/métodos , Cerâmica/química , Silanos/química , Materiais Dentários/química , Corrosão Dentária/métodos , Porcelana Dentária/química , Técnicas In Vitro , HumanosRESUMO
OBJECTIVE: Achieving a strong bond between Polyetheretherketone (PEEK) and veneering composites is challenging due to PEEKs low surface energy. This study examined the effects of sandblasting and bonding on the shear bond strength (SBS) between veneering composite and pigmented PEEK, considering artificial aging. METHODS: Of three pigmented PEEK compounds (DC4420R, DC4450R, DC4470R; Evonic Operations GmbH, Marl, Germany), 40 specimens each were milled and polished up to 2500 grit. Prior to veneering, specimens were divided into 4 subgroups: Subgroup 1: Polishing; 2: Polishing + bonding; 3: Sandblasting; 4: Sandblasting + bonding. Sandblasting was performed using Al2O3. Adhesive was an agent containing MMA (Signum Universal Bond, Kulzer GmbH, Hanau, Germany). After veneering (Composite, Kulzer GmbH) the subgroups were divided into 2 subgroups. One subgroup was immersed in 37 °C warm distilled water for 24 h. The second subgroup was artificially aged by thermocycling (TCL) with 5000 cycles in distilled water (5 °C / 55 °C; 30 s). Surface roughness, water contact angles and failure modes were recorded. SBS was measured using a universal testing machine. RESULTS: Results demonstrated that the combination of sandblasting and bonding significantly improved the SBS compared to polishing alone. PEEK color did not significantly influence the SBS. Aging by TCL had a negative effect on the SBS. SIGNIFICANCE: Sandblasting and the use of an adhesive containing MMA were found to be effective in achieving satisfactory SBS between veneering composite and pigmented PEEK surfaces. These pretreatment methods demonstrate their potential for establishing durable and reliable bonding in clinical applications.
Assuntos
Benzofenonas , Resinas Compostas , Colagem Dentária , Análise do Estresse Dentário , Facetas Dentárias , Cetonas , Teste de Materiais , Polietilenoglicóis , Polímeros , Resistência ao Cisalhamento , Propriedades de Superfície , Cetonas/química , Resinas Compostas/química , Polímeros/química , Polietilenoglicóis/química , Polimento Dentário , Corrosão Dentária/métodos , Óxido de Alumínio/química , CorRESUMO
Ceramic based on zirconium dioxide (ZD) is a modern, durable material for the manufacture of dentures. It is known that ZD is not etched as glass-ceramic, making it difficult to prepare this material before fixing. OBJECTIVE: To study the impact of various methods of surface treatment of ZD-based ceramic on adhesive strength. MATERIALS AND METHODS: Sandblasting with Al2O3 particles sized 50 µm and application of primers with 10-MDP phosphate monomer were used. Adhesive strength values for following 4 groups of samples were obtained: 1st group - RelyX U200 + sandblasting + Compofix new primer (n=9); 2nd group - Compofix + sandblasting + Compofix new primer (n=9); 3rd group - Panavia F 2.0 + sandblasting (n=9); 4th group (control) - Variolink Esthetic DC + sandblasting + Monobond Plus primer (n=9). RESULTS: The highest strength of adhesion was in the 4th group - 48.71±5.71MPa, the smallest in the 3rd group - 9.49±35.24 MPa. Fully domestic components used in the 2nd group allowed to obtain values of 42.50±9.79 MPa. Adhesive strength in the 1st group was 34.11±4.78 MPa. CONCLUSION: The absence of the 10-MDP-based primers application in the preparation of ZD ceramic reduces the adhesive strength between resin cement and its surface. The domestic set for fixation of dentures can be effectively used for ZD on the same basis as European analogue.
Assuntos
Propriedades de Superfície , Zircônio , Zircônio/química , Teste de Materiais , Cerâmica/química , Colagem Dentária/métodos , Cimentos de Resina/química , Humanos , Cimentos Dentários/química , Corrosão Dentária/métodosRESUMO
OBJECTIVES: The study aimed to evaluate the debonding resistance of three different endocrown designs on molar teeth, using three different zirconia surface pretreatments. MATERIAL AND METHOD: Ninety human mandibular first molars were divided into three main groups: endocrowns without ferrule, with 1 mm ferrule, and with 2 mm ferrule. The subgroups were defined by their surface pretreatment method used (n = 15): 50 µm alumina air-particle abrasion, silica coating using 30 µm Cojet™ particles, and Zircos-E® etching. The endocrowns were fabricated using multilayer zirconia ceramic, cemented with self-adhesive resin cement, and subjected to 5000 thermocycles (5-55°C) before debonding. The data obtained were analyzed using a two-way ANOVA. RESULTS: All test specimens survived the thermocyclic aging. The results indicated that both the preparation design and the surface treatment had a significant impact on the resistance to debonding of the endocrowns (p < .001). The 2 mm ferrule followed by the 1 mm ferrule designs exhibited the highest debonding resistance, both were superior to the endocrown without ferrule. Zircos-E® etching and silica coating yielded comparable debonding resistance, which were significantly higher than alumina air-particle abrasion. All endocrowns demonstrated a favorable failure mode. CONCLUSIONS: All designs and surface treatments showed high debonding resistance for a single restoration. However, ferrule designs with Zircos-E® etching or silica coating may represent better clinical options compared to the nonferrule design or alumina airborne-particle abrasion. Nonetheless, further research, including fatigue testing and evaluations with different luting agents is recommended.
Assuntos
Óxido de Alumínio , Dióxido de Silício , Propriedades de Superfície , Zircônio , Óxido de Alumínio/química , Humanos , Dióxido de Silício/química , Zircônio/química , Dente Molar , Teste de Materiais , Abrasão Dental por Ar/métodos , Cimentos de Resina/química , Corrosão Dentária/métodos , Análise do Estresse Dentário , Planejamento de Prótese DentáriaRESUMO
BACKGROUND: This study aims to evaluate the effect of surface treatment and resin cement on the shear bond strength (SBS) and mode of failure of polyetheretherketone (PEEK) to lithium disilicate ceramic (LDC). This is suggested to study alternative veneering of PEEK frameworks with a ceramic material. METHODS: eighty discs were prepared from PEEK blank and from lithium disilicate ceramic. Samples were divided into four groups according to surface treatment: Group (A) air abraded with 110 µm Al2O3, Group (AP) air abrasion and primer application, Group (S) 98% sulfuric acid etching for 60 s, Group (SP) Sulfuric acid and primer. Each group was subdivided into two subgroups based on resin cement type used for bonding LDC:1) subgroup (L) self- adhesive resin cement and 2) subgroup (B) conventional resin cement (n = 10). Thermocycling was done for all samples. The bond strength was assessed using the shear bond strength test (SBS). Failure mode analysis was done at 50X magnification with a stereomicroscope. Samples were chosen from each group for scanning electron microscope (SEM). The three-way nested ANOVA followed by Tukey's post hoc test were used for statistical analysis of results. Comparisons of effects were done utilizing one way ANOVA and (p < 0.05). RESULTS: The highest mean of shear bond strength values was demonstrated in Group of air abrasion with primer application using conventional resin cement (APB) (12.21 ± 2.14 MPa). Sulfuric acid groups showed lower shear bond strength values and the majority failed in thermocycling especially when no primer was applied. The failure mode analysis showed that the predominant failure type was adhesive failure between cement and PEEK, while the remaining was mixed failure between cement and PEEK. CONCLUSION: The air abrasion followed by primer application and conventional resin cement used for bonding Lithium Disilicate to PEEK achieved the best bond strength. Primer application did not have an effect when self-adhesive resin cement was used in air-abraded groups. Priming step is mandatory whenever sulfuric acid etching surface treatment is utilized for PEEK.
Assuntos
Benzofenonas , Colagem Dentária , Porcelana Dentária , Análise do Estresse Dentário , Cetonas , Teste de Materiais , Polietilenoglicóis , Polímeros , Cimentos de Resina , Resistência ao Cisalhamento , Propriedades de Superfície , Colagem Dentária/métodos , Condicionamento Ácido do Dente/métodos , Ácidos Sulfúricos , Cerâmica/química , Abrasão Dental por Ar/métodos , Óxido de Alumínio , Facetas Dentárias , Corrosão Dentária/métodos , HumanosRESUMO
STATEMENT OF PROBLEM: The surface topography of metal substrate can affect its bond to porcelain. A neodynium-doped yttrium aluminum garnet (Nd:YAG) laser has been introduced to modify the metal surface topography and improve porcelain bond strength. However, studies on the effect of laser etching on metal to porcelain bond strength are lacking. PURPOSE: The purpose of this in vitro study was to determine the effect of Nd:YAG laser etching on the surface roughness and wettability of and the porcelain bond strength to cobalt chromium (Co-Cr) substrate fabricated by milling and direct metal laser sintering (DMLS). MATERIAL AND METHODS: Thirty-two 0.5×3×25-mm Co-Cr specimens were fabricated by milling soft Co-Cr (M group) and DMLS Co-Cr metal powder (DML group). The surface topography of representative specimens from each study group was assessed under a scanning electron microscope (SEM) and an atomic force microscope (AFM). All specimens were assessed for surface roughness using a contact profilometer, and for wettability with a contact angle goniometer. Half of the specimens of each study group (n=8) were subjected to surface laser etching by using a Nd:YAG laser. The specimens subjected to etching were assessed again for surface topography and wettability. All specimens in both study groups were veneered with porcelain. The porcelain bond strength was tested with a 3-point bend test in a universal testing machine. The results were statistically analyzed with 2-way ANOVA test followed by the post hoc Tukey test for pairwise comparisons (α=.05). RESULTS: After etching, the M group had a higher mean ±standard deviation Ra and Rz of 2.9 ±0.6 and 17.7 ±3.2 µm and significantly better wettability and bond strength of 79 ±6 and 52 ±13 MPa. In contrast, after etching, the DMLS group had a significantly lower Ra and Rz of 7.9 ±2.4 and 41.8 ±9.3 µm and significantly lower wettability and bond strength of 87 ±4 and 70 ±10 MPa. The DMLS group had a significantly higher roughness and bond strength than the M group before and after laser etching. The SEM and AFM showed different surface topography in the study groups. CONCLUSIONS: The manufacturing process of Co-Cr substrate had a significant effect on surface characteristics and porcelain bond strength. Laser etching improved the surface topography and bond strength of milled Co-Cr but not of DMLS Co-Cr.
Assuntos
Ligas de Cromo , Colagem Dentária , Porcelana Dentária , Lasers de Estado Sólido , Propriedades de Superfície , Ligas de Cromo/química , Porcelana Dentária/química , Colagem Dentária/métodos , Microscopia Eletrônica de Varredura , Corrosão Dentária/métodos , Molhabilidade , Microscopia de Força Atômica , Teste de Materiais , Análise do Estresse Dentário , Humanos , Técnicas In VitroRESUMO
PURPOSE: To investigate the effects of airborne-particle abrasion and nanosilica (nano-Si) infiltration treatment on the surface characteristics of dental zirconia. MATERIALS AND METHODS: A total of 15 unsintered zirconia ceramic green bodies (10 × 10 × 3 mm) were divided into three groups (n = 5): Group C, no treatment after sintering; Group S, airborne-particle abrasion with 50-µm aluminum oxide particles after sintering; and Group N, infiltration of nano-Si followed by sintering and hydrofluoric acid (HF) etching. The zirconia disks' surface roughness was analyzed by atomic force microscopy (AFM). The surface morphology of the specimens was analyzed using scanning electron microscopy (SEM), and the chemical composition was analyzed by energy-dispersive x-ray (EDX). Data were statistically analyzed by the Kruskal-Wallis test (P < .05). RESULTS: Zirconia surface treatments by infiltration of nano-Si, sintering, and HF etching showed multiple changes in the surface features. The surface roughness of Groups C, S, and N were 0.88 ± 0.07 µm, 1.26 ± 0.10 µm, and 1.69 ± 0.15 µm, respectively. The surface roughness of Group N was significantly higher than that of Groups C and S (P < .05). EDX analysis showed peaks that corresponded to silica (Si) after infiltration with colloidal Si that disappeared following acid etching. CONCLUSIONS: Infiltrating nano-Si increases the surface roughness of zirconia. The formation of retentive nanopores on the surface potentially improves the zirconia-resin cement bonding strengths.
Assuntos
Colagem Dentária , Humanos , Propriedades de Superfície , Cerâmica/química , Zircônio/química , Cimentos de Resina/química , Óxido de Alumínio/química , Teste de Materiais , Microscopia Eletrônica de Varredura , Corrosão DentáriaRESUMO
OBJECTIVES: To compare the clinical performance of mildly acidic universal adhesives Scotchbond Universal (SU, 3M Oral Care, St Paul, MN, USA) and Prime & Bond Elect (PBE, Dentsply Sirona, Charlotte, NC, USA) in the restoration of noncarious cervical lesions (NCCLs). METHODS AND MATERIALS: A total of 63 patients in need of 203 NCCL restorations participated in this randomized controlled clinical trial. Notch-shaped lesions were restored with Kalore (GC Corporation, Tokyo, Japan) after application of either SU or PBE, following the etch-and-rinse (ER) or self-etch (SE) techniques. Subjects were followed up for 60 months. The focus of the statistical analyses was on the change of outcome over time as assessed by the Modified USPHS rating system (ie, Alfa vs Bravo + Charlie outcomes). Logistic regression was performed for each outcome separately with compound symmetric variance-covariance structure assumed to consider a correlation of restorations within subjects. All analyses were conducted using SAS 9.4 (SAS, Cary, NC, USA). RESULTS: One-hundred twenty-nine teeth in 35 subjects were assessed at the 60-month follow-up. In addition, three restorations that failed prior to the 60-month evaluation, two of which were in subjects who did not present for the 60-month follow-up, were included in the statistical analysis. In total, two restorations in the SU_ER group and three restorations in the PBE_SE group failed the retention category. Statistically significant differences were obtained for the comparison of restorations in the PBE_SE and PBE_ER groups, where the former was 58% less likely to maintain a score of Alfa for marginal discoloration than the latter. CONCLUSIONS: SU and PBE demonstrated acceptable clinical performance at 60 months with regard to restoration retention. Phosphoric-acid etching of the NCCLs prior to adhesive application significantly improved the performance of PBE in regard to marginal discoloration.
Assuntos
Cimentos Dentários , Adesivos Dentinários , Humanos , Adesivos Dentinários/química , Resinas Compostas/química , Corrosão Dentária/métodos , Restauração Dentária Permanente/métodos , Adaptação Marginal Dentária , Cimentos de Resina/uso terapêutico , Cimentos de Resina/química , Colo do Dente , AdesivosRESUMO
PURPOSE: The efficacy of etch-and-rinse, selective enamel-etching, and self-etching protocols for universal adhesives in follow-ups of over 12 months was compared in a network meta-analysis. STUDY SELECTION: Randomized controlled trials (RCTs) published from 1998 to 2022 that compared marginal staining, marginal adaptation, retention and fractures, post-operative sensitivity, or recurrence of caries that took place over 12-months post-restoration were selected. A network meta-analysis determined the performance of each adhesive protocol. RESULTS: After screening 981 articles, 16 RCTs were subjected to data extraction. Of which, 674 patients with 2816 restorations, were included in the network meta-analysis. The pooled risk of marginal discoloration following self-etching was significantly higher than that following etch-and-rinse at over 12, 24, and 36 months, which was time-dependent. The pooled risks of unfavorable marginal adaptation and unfavorable retention and fractures following self-etching were also significantly higher than that following etch-and-rinse, with the rates of unfavorable retention and fractures in non-carious cervical lesions increasing in a time-dependent manner. The pooled risks of marginal discoloration, unfavorable marginal adaptation, retention and fractures were similar between etch-and-rinse and selective enamel-etching protocols. Post-operative hypersensitivity and recurrence of caries were not significantly different among etch-and-rinse, selective enamel-etching, and self-etching protocols. CONCLUSIONS: In follow-ups over 12 months, esthetic and functional outcomes of restorations completed with an etch-and-rinse adhesive protocol were superior to the ones achieved with a self-etching strategy without selective enamel-etching. Selective enamel etching is recommended for self-etching systems. Biological responses were similar for all three adhesive strategies.
Assuntos
Adesivos , Restauração Dentária Permanente , Retenção de Dentadura , Humanos , Cárie Dentária/epidemiologia , Adaptação Marginal Dentária , Restauração Dentária Permanente/efeitos adversos , Restauração Dentária Permanente/métodos , Seguimentos , Metanálise em Rede , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento , Método Duplo-Cego , Corrosão Dentária/métodosRESUMO
OBJECTIVES: Orthodontic brackets are increasingly bonded to the surface of zirconium crowns due to the growing aesthetic demands in adults' restorations. Therefore, providing a reliable bond between these substrates is of great importance. This study aimed at investigating the shear bond strength (SBS) of orthodontic metal brackets bonded to zirconium treated by sandblasting. In addition, the value was compared with SBS between metal brackets and enamel. MATERIALS AND METHODS: Samples were divided into three groups including first premolar enamel specimens (n=20), untreated zirconium blocks (n=20) and sandblasted zirconium blocks (n=20). Enamel specimens underwent etching and bonding procedures using 37% phosphoric acid and 3M™ Scotchbond™ Universal adhesive. Zirconium blocks were randomly allocated to two groups. The first group was prepared by sandblasting with 50µm aluminium oxide particles (Al2O3) under 4 bars pressure followed by bonding brackets with 3M™ Scotchbond™ Universal adhesive. Metal brackets were also bonded to the untreated zirconium group using the same adhesive. All samples underwent thermocycling, and SBS was calculated using a universal testing machine with a crosshead speed of 1mm/min. Data were analysed using One-way Anova and Tukey's tests. RESULTS: The highest SBS was recorded in sandblasted zirconium group (26.17±8.22MPa) followed by enamel group (23.667±7.00MPa) and untreated zirconium group (11.49±7.00MPa). There was a significant difference between the SBS of untreated zirconium and that of two other groups. CONCLUSION: Perfect SBS was achieved by sandblasting pre-treatment, comparable to that of enamel. Therefore, sandblasting of zirconium crowns is recommended prior to bonding orthodontic brackets.
Assuntos
Colagem Dentária , Braquetes Ortodônticos , Condicionamento Ácido do Dente/métodos , Adulto , Coroas , Colagem Dentária/métodos , Cimentos Dentários , Esmalte Dentário , Corrosão Dentária/métodos , Análise do Estresse Dentário , Estética Dentária , Humanos , Teste de Materiais , Cimentos de Resina/química , Resistência ao Cisalhamento , Estresse Mecânico , Propriedades de Superfície , ZircônioRESUMO
PURPOSE: To assess the shear bond strength of composite resin to polyether ether ketone (PEEK) after mechanical and chemical surface treatments. MATERIALS AND METHODS: A total of 48 PEEK discs were fabricated and divided equally into four surface treatment groups (n = 12 each): (1) airborne particle abrasion with 50-µm alumina particles at 2 MPa pressure for 10 seconds; (2) 98% sulfuric acid etching for 1 minute; (3) airborne particle abrasion and sulfuric acid etching; and (4) no surface treatment. Specimens were conditioned, then Gradia composite veneer (GC) was applied to the PEEK surfaces and polymerized. Bond strength was measured with shear bond test using a universal testing machine. One-way analysis of variance and Tukey post hoc tests were applied for statistical analysis. RESULTS: The mean shear bond strength values of the sulfuric acid-etched group were higher than that of the airborne particle abrasion + acid etching, airborne particle abrasion, and control groups (P < .05). Mean shear bond strength values for the airborne particle abrasion + acid etching samples were higher than for the control and airborne particle abrasion groups (P < .05). CONCLUSION: There was no significant difference between the samples treated with airborne particle abrasion and the control group.
Assuntos
Colagem Dentária , Corrosão Dentária , Óxido de Alumínio/química , Benzofenonas , Análise do Estresse Dentário , Éteres , Cetonas , Teste de Materiais , Polímeros , Cimentos de Resina/química , Resistência ao Cisalhamento , Propriedades de SuperfícieRESUMO
STATEMENT OF PROBLEM: Polyaryletherketones (PAEKs) are high-performance polymer materials in which polyetheretherketone (PEEK) and polyetherketoneketone (PEKK) are the most used. Although mechanical and shear bonding strength tests have been performed on the 2 materials, studies on the influence of processing on bonding are scarce. PURPOSE: The purpose of this in vitro study was to determine the influence of the surface treatment and the manufacturing process on the shear bond strength of veneering composite resin to PEKK and PEEK. MATERIAL AND METHODS: Thirty pressed PEKK, 30 milled PEKK, and 30 milled PEEK specimens were distributed in 6 groups (n=13) as per the manufacturing process and treatment surface. The specimens were either treated with airborne-particle abrasion with 110-µm aluminum oxide, or no surface treatment was applied. Moreover, the PEKK specimens were grouped regarding their manufacturing process, as either milled or heat-pressed. The specimens were all bonded by using a methyl methacrylate-based adhesive (visio.link), and composite resin (Gradia Revolution 2) was bonded to the specimens. An Instron universal machine was used to calculate the shear bond strength between the PEEK or PEKK and the composite resin. Two specimens from each group had their topography modification assessed with a scanning electron microscope. Statistical analysis was performed by using a 3-way ANOVA for multiple comparisons (α=0.05) RESULTS: The groups that were surface treated with 110-µm aluminum oxide (Al2O3) before bonding showed significantly higher shear bond strength (P=.001) than the other groups. However, no statistically significant difference was observed among the groups, regardless of the manufacturing process (milled or heat-pressed) (P=.607). CONCLUSIONS: PEEK and PEKK surfaces treated with 110-µm aluminum oxide airborne-particle abrasion displayed better shear bond strength to composite resin. The manufacturing process (milled or heat-pressed) did not significantly affect the bond strength of PEKK when subjected to the same bonding process.
Assuntos
Colagem Dentária , Corrosão Dentária , Propriedades de Superfície , Teste de Materiais , Polímeros , Resinas Compostas/química , Resistência ao Cisalhamento , Cetonas/química , Polietilenoglicóis/química , Óxido de Alumínio/química , Cimentos de Resina/químicaRESUMO
OBJECTVE: Several pre-cementation procedures have been advocated to enhance adhesion between zirconia and resin-based cement. There is, however, limited documentation on how these pre-treatments affect the strength of zirconia crowns as most tests are performed on discs or bars. The aim was to assess the effect of pre-cementation procedures on fracture mode, fracture strength and cement retention on zirconia. METHODS: Two dental zirconia materials with different yttria content were assessed (<4 and>5 mol%). Both discs (n = 45) and crown-shaped specimens (n = 30) of the two materials were pretreated with either air-abrasion or hot-etching with KHF2 and compared with untreated controls with regards to surface roughness, crystallography, wettability, cement adhesion and fracture strength. RESULTS AND SIGNIFICANCE: Air-abrasion improves adhesion and strength of zirconia with moderate yttria content (<4 mol%). Acid etching with heated KHF2 showed the best effect on strength and cement retention on zirconia with higher yttria content (>5 mol%). Application of KHF2 was, however, complicated on crown-shaped specimens. Pre-treatment and cementation protocols should be optimized for different dental zirconias to improve both strength and retention.
Assuntos
Cimentação , Colagem Dentária , Cerâmica , Corrosão Dentária , Análise do Estresse Dentário , Teste de Materiais , Cimentos de Resina , Propriedades de Superfície , Ítrio , ZircônioRESUMO
RESUMEN: Los laminados vitrocerámicos ultradelgados constituyen una alternativa conservadora para la resolución de alteraciones estéticas. Sin embargo, su acondicionamiento con ácido fluorhídrico suele no estar exento de complicaciones, por lo que el uso de un sistema autograbante en base a polifluoruro de amonio (Monobond Etch&Prime, MEP) permite disminuir el riesgo de sobregrabado, simplificando la técnica. El presente reporte presenta el seguimiento a dieciocho meses de un caso clínico resuelto mediante laminados vitrocerámicos acondicionados únicamente con MEP. Caso. Paciente joven con alteraciones estéticas en el sector anterosuperior. Se realizaron preparaciones conservadoras para la confección de laminados ultradelgados en disilicato de litio (e.maxPress). Las vitrocerámicas fueron acondicionadas sólo con MEP y se cementaron con Variolink Esthetic LC. Al año y medio las restauraciones se observaron indemnes, manteniendo un buen ajuste marginal y ausencia de tinciones. Conclusiones. MEP aparece como una alternativa prometedora para reemplazar al ácido fluorhídrico en la cementación de laminados vitrocerámicos.
ABSTRACT: Ultrathin glass-ceramic veneers are a conservative approach for the restorative treatment of aesthetic disorders in the anterior region. However, surface conditioning with hydrofluoric acid of the thin structures can be usually a challenging step. Therefore, the use of a self-etching ceramic primer containing ammonium polyfluoride (Monobond Etch&Prime, MEP) offers a simplified technique with a reduced risk of overetching. Here we present an 18-month follow-up of ultrathin glass-ceramic veneers conditioned with MEP only. Case. Young female patient with an aesthetic disorder in the front region. The four upper incisors were conservatively prepared for ultrathin lithium disilicate (e.maxPress) veneers. Pre-treatment of the glass-ceramics consisted only of MEP application, followed by adhesive cementation with Variolink Esthetic LC. At the 1.5-year recall, the restorations appeared undamaged, with no marginal gap or staining. Conclusions. MEP constitutes a promising alternative to hydrofluoric acid for the adhesive cementation of glass-ceramic veneers.
Assuntos
Humanos , Feminino , Adulto , Cimentos Dentários , Facetas Dentárias , Corrosão Dentária/métodos , Resultado do Tratamento , Estética Dentária , Compostos de AmônioRESUMO
OBJECTIVE: To compare the shear bond strength of enamel or dentin conditioned with either Er,Cr:YSGG (erbium, chromium: yttrium-scandium-gallium-garnet) laser or phosphoric acid to composite resin restoration. MATERIAL AND METHODS: Forty posterior human extracted teeth were used. After mesiodistal sectioning of the teeth crowns, the samples were randomly divided into two groups-in the first group (E), bonding was performed on the enamel after roughening and in the second group (D), the enamel was removed and bonding was performed on the dentin. These groups were further randomly divided into two subgroups according to the type of etching (n = 20 each). In the acid-etched groups (EA and DA), the surfaces were etched with 37% phosphoric acid. In the laser-conditioned groups (EL and DL), the surfaces were conditioned with Er,Cr:YSGG laser. Total-etch adhesive system was used to bond all the 80 specimens resin composite. The composite was vertically light-cured, and the specimens were subjected to a shear bond strength test. Modes of bond failure were determined with a stereomicroscope. RESULTS: The highest shear bond strength was observed for the DA group (16.25 ± 1.10 MPa, p < 0.0001), whereas the lowest was observed for the DL group (8.56 ± 0.67 MPa). The adhesive failure mode was the most frequently observed in all groups. CONCLUSIONS: The shear bond strength of composite resin bonded to enamel and dentin etched with phosphoric acid was higher than when conditioned with Er,Cr:YSGG laser. Thus, laser conditioning is not recommended.
Assuntos
Colagem Dentária , Lasers de Estado Sólido , Resinas Compostas , Esmalte Dentário , Corrosão Dentária , Análise do Estresse Dentário , Dentina , Humanos , Teste de MateriaisRESUMO
The purpose of this study was to investigate the shear bond strength (SBS) of ceramic discs luted to differently etched enamel and dentin surfaces. Occlusal surfaces of 64 carious-free human molars and vestibule surfaces of 64 first maxillary incisors were ground to get flat superficial dentin and flattened enamel respectively. After generating 4 groups according to the surface etching method (37% orthophosphoric acid, Er:YAG laser-contact handpiece/scanning handpiece (1 or 2 times of scanning)), ceramic discs were luted to the surfaces with adhesive resin cement (Variolink N, Vivadent Ets., Schaan/Liechtenstein). After etching and cementation, thermocycling of 5000 cycles (Sd Mechatronik Gmbh, Feldkirchen-Westerham, Germany) and SBS test (Servopulser EHFFD1; Shimadzu, Kyoto, Japan) were performed respectively. The surface morphologies of 2 specimens, etched enamel and dentin, prepared for each group were examined with SEM analysis. Failure modes were determined under a USB digital microscope. Data were analyzed with one-way analysis of variance (ANOVA) and Tukey HSD test (α = 0.05). SBS values in dentin surfaces showed statistically significant differences (p < 0.05) among tested groups. The highest SBS among dentin groups was determined in the group which had 2 times etching by Er:YAG laser (11.42 MPa) by a scanning handpiece. No statistical differences were observed in the other dentin or enamel groups. Laser etching seems to be a viable alternative to acid etching on both enamel and dentin surfaces while double etching of dentin with a scanning handpiece can improve the adhesion.
Assuntos
Cimentação , Cerâmica/química , Colagem Dentária , Esmalte Dentário/efeitos da radiação , Corrosão Dentária , Dentina/efeitos da radiação , Lasers de Estado Sólido , Cimentos de Resina/química , Esmalte Dentário/ultraestrutura , Dentina/ultraestrutura , Humanos , Ácidos Fosfóricos/química , Resistência ao CisalhamentoRESUMO
The aim was to evaluate the optical changes of bleached human dentin and the efficacy of Er,Cr:YSGG laser on micro-shear bond strength (µSBS) of two adhesive systems for immediate and delayed applications. Seventy-two human dentin specimens (1 mm) were obtained. Colour measurements of 30 specimens (control and bleaching groups) were made at baseline, after bleaching and a 7-day delay. Differences at colour (ΔE00), translucency (ΔTP00) and whiteness (ΔWID) were calculated by recorded data. Forty-two specimens were used to compare µSBS of a self-etch (Clearfil SE Bond [SE]) and an etch-and-rinse (Prime&Bond NT [PBNT]) adhesive to bleached dentin. Additional to a negative group, six groups were contemplated for each adhesive, considering the time of composite application (immediate, delayed) and whether additional surface treatment by laser (1 W, 2 W) or not. Colour and µSBS data were statistically analysed. For optical analysis, only ΔE00 and ΔWID calculated for the difference between baseline and bleaching were found significantly different for control and bleaching groups. Whiteness of bleached specimens was remarkably decreased after a 7-day delay. Despite immediate applications of SE showing lower µSBS than negative control, delayed applications showed no significant differences except that of the 2 W laser etching. For PBNT, laser etching increased µSBS for both of the immediate and delayed applications, and no significant difference was observed from negative control. Related with the preferred adhesive system, Er,Cr:YSGG laser etching can be an alternative for optimal bond strength of immediate restorations, but the clinicians should always keep in mind that perceived colour and whiteness will change by the passing time which can affect the shade match.
Assuntos
Colagem Dentária , Cimentos Dentários/farmacologia , Corrosão Dentária , Dentina/efeitos da radiação , Lasers de Estado Sólido , Clareamento Dental , Humanos , Cimentos de ResinaRESUMO
STATEMENT OF PROBLEM: Published data have shown that a mechanical surface treatment of titanium surfaces increases bonding potential. However, most of the studies are based on shear or tensile tests performed on flat-surfaced specimens and do not take into consideration the retention given by the titanium base (ti-base) axial walls and the thermomechanical loading seen in a clinical setting. PURPOSE: The purpose of this in vitro study was to evaluate the influence of different airborne-particle abrasion (APA) methods of the ti-base surface on the stability of the bonded interface and retention forces between these titanium bases and lithium disilicate crowns after thermomechanical aging. MATERIAL AND METHODS: Sixty internal connection implants (Conelog) were restored with lithium disilicate crowns and bonded to the corresponding ti-bases (Conelog). The ti-bases were divided into 4 groups (n=15), 3 experimental groups applying different APA methods, 30-µm silica-modified Al2O3 particles (CoJet) (30-SiO-AlO), 50-µm Al2O3 (Cobra Aluoxyd) (50-AlO), 110-µm silica-modified Al2O3 particles (Rocatec Plus) (110-SiO-AlO), and 1 control group (NoT). Ti-bases were airborne-particle abraded (10 seconds, 0.25 MPa at a 10-mm distance) under standardized conditions in a custom-made APA device. All crowns were cemented with a resin cement (Multilink Hybrid Abutment). After aging (1 200 000 cycles, 49 N, 1.67 Hz; 5 °C-55 °C, 120 seconds), all specimens were assessed for the presence of bond failures by optical microscopy (×50). The retention forces (N) were tested by using a pull-off test (0.5mm/min). Modes of failure were classified (Type 1, 2, or 3). An additional ti-base representing each group was prepared for surface roughness (µm) calculation (Ra, Rc, Rz) with a noncontact laser profilometer, and representative scanning electron microscope (SEM) images were recorded (×1000). Chi-squared tests were performed to analyze the bonded interface failure and modes of failure, and a Kruskal-Wallis test was selected to evaluate retention force values (α=.05). RESULTS: The percentages of bonding failure after aging were 73.3% (NoT), 40% (30-SiO-AlO), 6.7% (50-AlO), and 40% (110-SiO-AlO). The stability of the bonded interface was influenced by the APA method applied (P<.05). Mean ±standard deviation retention force values varied from 206.3 ±86.3 N (NoT) to 420 ±139.5 N (50-AlO), and the differences between these 2 groups were significant (P<.05). Modes of failure were predominantly Type 2 (30-SiO-AlO; 50-AlO; 110-SiO-AlO) and Type 3 (NoT). CONCLUSIONS: Airborne-particle abrasion of the titanium surface increased the bond stability and retention forces between the ti-base and the respective crown. The use of 50-µm Al2O3 provided the most stable bonded interface among the different treatments.