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1.
BMC Cancer ; 21(1): 1083, 2021 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-34620124

RESUMO

BACKGROUND: The aim of the study was to estimate the minimally important difference (MID) for interpreting group-level change over time, both within a group and between groups, for the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) scores in patients with prostate cancer. METHODS: We used data from two published EORTC trials. Clinical anchors were selected by strength of correlations with QLQ-C30 scales. In addition, clinicians' input was obtained with regard to plausibility of the selected anchors. The mean change method was applied for interpreting change over time within a group of patients and linear regression models were fitted to estimate MIDs for between-group differences in change over time. Distribution-based estimates were also evaluated. RESULTS: Two clinical anchors were eligible for MID estimation; performance status and the CTCAE diarrhoea domain. MIDs were developed for 7 scales (physical functioning, role functioning, social functioning, pain, fatigue, global quality of life, diarrhoea) and varied by scale and direction (improvement vs deterioration). Within-group MIDs ranged from 4 to 14 points for improvement and - 13 to - 5 points for deterioration and MIDs for between-group differences in change scores ranged from 3 to 13 for improvement and - 10 to - 5 for deterioration. CONCLUSIONS: Our findings aid the meaningful interpretation of changes on a set of EORTC QLQ-C30 scale scores over time, both within and between groups, and for performing more accurate sample size calculations for clinical trials in prostate cancer.


Assuntos
Deterioração Clínica , Diarreia , Inquéritos Epidemiológicos , Neoplasias da Próstata , Qualidade de Vida , Índice de Gravidade de Doença , Idoso , Dor do Câncer , Ensaios Clínicos Fase III como Assunto/estatística & dados numéricos , Reembasadores de Dentadura , Europa (Continente) , Fadiga , Humanos , Masculino , Pessoa de Meia-Idade , Medidas de Resultados Relatados pelo Paciente , Desempenho Físico Funcional , Interação Social , Fatores de Tempo
2.
Artigo em Inglês | MEDLINE | ID: mdl-34574415

RESUMO

The main functional feature of elastomeric soft linings materials is the ability to discharge loads in the tissues of the mucosa. As a result, there are fewer injuries to the mucosa and chewing ability increases. In addition, these prostheses are more comfortable in the patient's opinion. To obtain the equal distribution of forces on the muco-bone basis and to reduce the traumatizing effect of the denture plate for patients using full dentures, soft lining materials can be used. AIM OF THE STUDY: the aim of the work was a comparative laboratory study of ten materials used for soft lining of acrylic complete dentures. METHODOLOGY: Materials based on acrylates (Vertex Soft, Villacryl Soft, Flexacryl Soft) and on silicones (Sofreliner Tough Medium, Sofreliner Tough Medium, Ufi Gel SC, GC Reline Soft, Elite Soft Relining, Molloplast) were compared. Laboratory tests include tests of changes in Shore'a A hardness of soft lining material. The tests were conducted taking into account 90 day term aging in the distilled water environment based on the methodology presented in the European Standard ISO 10139-2. RESULTS: For most silicone materials, only small changes in hardness were found in the range of 0.7 (Ufi Gel SC) to 3.3 (Sofreliner Tough Medium) on the Shore A scale. The exception was GC Reline Soft, for which a marked increase in hardness was noted. All materials based on acrylates were characterized by successive increase in hardness over time. However, in the case of the Vertex Soft material, the increase in hardness was relatively small (5.5 ShA).


Assuntos
Reembasadores de Dentadura , Dureza , Humanos , Teste de Materiais
3.
Ann Afr Med ; 20(2): 116-120, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34213478

RESUMO

Background: Clinically, adhesion failure is the most critical problem because of the failure of the optimal bond between denture base and the soft liner. Objectives: This study was performed to assess the tensile bond strength of two temporary soft liners to different denture base resins. Materials and Methods: Forty-eight blocks with 16 samples each of heat-cured denture base resin of three different types were fabricated from custom-made stainless steel die after de-waxing mold space. Surface roughening of each acrylic resin specimens which bonds with soft liners was done by abrading the surface and to this temporary soft liners (Perma soft denture liner and Pro soft denture liner) were bonded. The universal testing machine was used to test the tensile strength of bonded space. The results were statistically analyzed using the Statistical Software IBM SPSS Statistics for Windows, version 20.0. (Armonk, NY, USA: IBM Corp.) using the Chi-square test, Post hoc Tukey's HSD, and two way ANOVA tests. Results: It was observed that Perma soft was prevalent over Pro-soft denture liner on the basis of tensile bond strength with all three different types of denture base resins. Trevalon HI and acrylic composite exhibited better bond strength results with both Perma soft and GC Pro-soft denture liner as compared to other types of denture base resins. Conclusion: Perma soft had a better bond strength compared to Pro-soft denture liner in bonding modified denture base and conventional resins.


Assuntos
Resinas Acrílicas/química , Colagem Dentária , Bases de Dentadura , Reembasadores de Dentadura , Humanos , Teste de Materiais , Metilmetacrilatos , Propriedades de Superfície , Resistência à Tração
4.
Am J Dent ; 34(3): 132-136, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34143582

RESUMO

PURPOSE: To evaluate the effect of cigarette smoke on the surface roughness and color stability of three different soft denture liners. METHODS: Three commonly used commercially available, chair-side, long-term vinyl polysiloxane soft denture liners were used for this study [Sofreliner Tough (S) Soft, Silagum Comfort Soft Relining, and GC Reline Soft\. Thirty disk-shaped specimens of each material, with a diameter of 25 mm and thickness of 2 mm, were fabricated. Initial color and surface roughness readings were recorded. The specimens of each group were randomly divided into two groups (n= 15): the control group (C) and the study group (S). The control group specimens were stored in distilled water and the study group samples were exposed to cigarette smoke in a custom-made smoking chamber. Final color and surface roughness readings were recorded. A single operator performed all the measurements. The differences in color and surface roughness were calculated. Statistical analysis was performed using two-way ANOVA, post-hoc Tukey test, and paired t-test. For all the analyses, a P< 0.05 was regarded as statistically significant. RESULTS: After exposure to smoke, all groups showed a significantly perceptible color change (ΔE > 3.7). The greatest color change was seen in the Silagum group (ΔE= 8.94 ± 0.42), followed by the Sofreliner group (ΔE= 7.85 ± 0.47), with the least change in the GC reline group (ΔE= 3.87 ± 0.46). The mean color change after smoke exposure showed a statistically significant difference among all three study groups. The highest change in surface roughness was observed in the Silagum group (ΔR= 0.687 ± 0.14) followed by the GC reline group (ΔR= 0.265 ± 0.12), with the least change in the Sofreliner group (ΔR= 0.238 ± 0.06). There was a statistically significant difference between each group before and after exposure to smoke. Exposure to cigarette smoke caused significant changes in the color and surface roughness of all three soft denture liners tested in this study. The extent of these changes varied for each material. CLINICAL SIGNIFICANCE: Proper selection of soft denture liners is essential to avoid premature replacement, due to esthetic and hygiene reasons in cigarette smokers.


Assuntos
Reembasadores de Dentadura , Cor , Teste de Materiais , Fumaça , Fumar , Propriedades de Superfície , Tabaco
5.
J Tissue Viability ; 30(3): 402-409, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34052087

RESUMO

BACKGROUND: Factors such as the manufacturing materials, shape or even the mechanical and thermal response of sitting Pressure Redistribution Support Surfaces (PRSS) can be potential contributors to pressure ulcers. However, few studies have compared a number of characteristics of the most frequently used devices. OBJECTIVE: To compare three potential contributors to pressure ulcers in five commercial PRSS: pressure redistribution, temperature and perceived comfort. METHOD: Study with a cross-over randomized design in healthy volunteer participants. Data was collected in a temperature and relative humidity controlled environment. To assess thermal response, the temperature (Flir-E60) of the region of interest was captured before and after use of each PRSS for further analysis. The region of interest was the gluteal zone. To assess the pressure redistribution a pressure mat (XSensor®) was used between the 5 cushion and each study participant using a standardized method. Finally, a subjective perception questionnaire recorded comfort, adaptability and thermal sensation parameters. Data analysis levels of significance were set at 0.05. RESULTS: A total of 22 participants completed the assessments. There were no statistically significant differences in baseline temperatures between PRSS (>0.05). Pressure redistribution analysis showed significant differences between all PRSS in all variables evaluated except in the maximum and peak pressure index al sacrum. The subjective assessment suggested no major user-perceived differences between PRSS. CONCLUSION: Seat cushions made of open cell polyurethane foam blocks of variable hardness and the horseshoe cushion (also open cell polyurethane foam) seem to provide a more effective pressure relief characteristic than those injected with polyurethane foam and gel in most of the studied pressure variables. However, the cushions provide similar thermal response and perceived comfort.


Assuntos
Reembasadores de Dentadura/normas , Satisfação do Paciente , Cadeiras de Rodas/normas , Estudos Cross-Over , Reembasadores de Dentadura/psicologia , Reembasadores de Dentadura/estatística & dados numéricos , Humanos , Pressão/efeitos adversos , Postura Sentada , Traumatismos da Medula Espinal/complicações , Traumatismos da Medula Espinal/fisiopatologia , Termografia/métodos , Cadeiras de Rodas/psicologia , Cadeiras de Rodas/estatística & dados numéricos
6.
Molecules ; 26(5)2021 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-33799919

RESUMO

Herein, we investigated the surface characterization and biocompatibility of a denture-lining material containing Cnidium officinale extracts and its antifungal efficacy against Candida albicans. To achieve this, a denture-lining material containing various concentrations of C. officinale extract and a control group without C. officinale extract were prepared. The surface characterization and biocompatibility of the samples were investigated. In addition, the antifungal efficacy of the samples on C. albicans was investigated using spectrophotometric growth and a LIVE/DEAD assay. The results revealed that there was no significant difference between the biocompatibility of the experimental and control groups (p > 0.05). However, there was a significant difference between the antifungal efficiency of the denture material on C. albicans and that of the control group (p < 0.05), which was confirmed by the LIVE/DEAD assay. These results indicate the promising potential of the C. officinale extract-containing denture-lining material as an antifungal dental material.


Assuntos
Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Cnidium/química , Reembasadores de Dentadura , Extratos Vegetais/farmacologia , Antifúngicos/química , Antifúngicos/toxicidade , Linhagem Celular , Cor , Reembasadores de Dentadura/microbiologia , Fibroblastos/efeitos dos fármacos , Humanos , Teste de Materiais , Testes de Sensibilidade Microbiana , Extratos Vegetais/química , Extratos Vegetais/toxicidade , Propriedades de Superfície
7.
Dent Mater J ; 40(4): 918-927, 2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-33814534

RESUMO

We evaluated the influence of monomer type, plasticizer content, and powder/liquid (P/L) ratio on the setting characteristics of light-cured acrylic permanent soft denture liners based on poly(ethyl methacrylate/butyl methacrylate). Two monomers, iso-butyl methacrylate (i-BMA) and 2-ethylhexyl methacrylate (2-EHMA), that contained various concentrations of the plasticizer acetyl tributyl citrate (ATBC) and trace amounts of the photo initiator and reducing agent were used. The P/L ratio was 1.0 or 1.2. The gelation time was measured using a controlled stress rheometer. Materials with i-BMA had shorter gelation times than those for materials with 2-EHMA. The gelation time increased exponentially with increasing plasticizer content. A higher P/L ratio led to a shorter gelation time. The effects of monomer type and plasticizer content were larger than that for the P/L ratio. These results show that 2-EHMA is a suitable monomer for soft denture liners and that the setting characteristics can be controlled via ATBC content.


Assuntos
Reembasadores de Dentadura , Plastificantes , Citratos , Teste de Materiais , Metacrilatos , Pós
8.
J Dent ; 109: 103657, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33831504

RESUMO

OBJECTIVES: This randomised controlled trial aimed to compare the masticatory function between the silicone-based resilient denture liner and conventional denture among edentulous patients. METHODS: The trial included edentulous patients who were willing to have a new set of complete dentures. Participants were randomly assigned to receive mandibular complete dentures with either a 1) conventional denture base (CD group) or (2) silicone-based resilient denture liner (RD group). Masticatory performance (evaluated with gummy jelly) and the maximum occlusal force were measured at baseline, on final adjustment, and at 3 months after the final adjustment. The outcomes were analyzed using two-way mixed analysis of variance and a paired t-test. The statistical significance was set at p < 0.05. RESULTS: The masticatory performance was lower in the RD group than in the CD group; it increased significantly over time in the CD group, but not in the RD group. The maximum occlusal force in the RD group was significantly higher than that in the CD group; it increased significantly over time in the RD group, but not in the CD group. CONCLUSIONS: Silicone-based RD liners applied to mandibular complete dentures are effective in improving the maximum occlusal force but not the masticatory performance, as measured with gummy jelly. CLINICAL SIGNIFICANCE: Prior evidence has suggested that mandibular complete dentures with resilient denture liners improve masticatory function. However, the results of this study indicate that difficulties may remain with the mastication of foods with a certain texture (e.g., gummy jelly).


Assuntos
Reembasadores de Dentadura , Boca Edêntula , Prótese Total , Humanos , Mastigação , Silicones
9.
Dent Mater ; 37(5): 928-938, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33722400

RESUMO

OBJECTIVE: To investigate the tensile and flexural strength of poured, subtractive, and additive manufactured denture base methacrylates bonded to soft and hard relining materials after hydrothermal cycling and microwave irradiation. METHODS: This study included a conventional (CB), subtractive (SB), and additive (AB) base material as well as a soft (SCR) and hard (HCR) chairside and one hard laboratory-side (HLR) relining material. Reference bodies of the base materials and bonded specimens to the relining materials were produced with a rectangular cross-section. The specimens were either pre-treated by water storage (50 h, 37 °C), hydrothermal cycling (5000 cycles, 5 °C and 55 °C, 30 s each), or microwave irradiation (6 cycles, 640 W, 3 min, wet). A tensile and four-point bending test were performed for a total of 504 specimens. Data were analysed using multivariate analysis of variance (MANOVA) with post-hoc Tukey tests (α = 0.05). RESULTS: In comparison with the other reference groups SB showed marginally higher tensile and flexural strength (p < 0.047). Bond strength to SCR was affected neither by the base material nor by the pre-treatment (p > 0.085). HCR demonstrated twice the bond strength to AB compared with SB and CB (p ≤ 0.001). HLR showed the highest bond strength to CB (p ≤ 0.001). There was no difference between the specimens after hydrothermally cycling and microwave irradiation (p > 0.318). SIGNIFICANCE: The bond strength of hard relining materials to subtractive and additive manufactured denture bases differ compared with conventional pouring.


Assuntos
Colagem Dentária , Reembasadores de Dentadura , Resinas Acrílicas , Bases de Dentadura , Teste de Materiais , Propriedades de Superfície , Resistência à Tração
10.
J Appl Oral Sci ; 28: e20200639, 2021 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-33656098

RESUMO

OBJECTIVE: To evaluate the surface morphology and in vitro leachability of temporary soft linings modified by the incorporation of antifungals in minimum inhibitory concentrations (MIC) for Candida albicans biofilm. METHODOLOGY: Specimens of soft lining materials Softone and Trusoft were made without (control) or with the addition of nystatin (Ny), miconazole (Mc), ketoconazole (Ke), chlorhexidine diacetate (Chx), or itraconazole (It) at their MIC for C. albicans biofilm. The surface analyses were performed using Confocal laser scanning microscopy after 24 h, 7 days, or 14 days of immersion in distilled water at 37ºC. In vitro leachability of Chx or Ny from the modified materials was also measured using Ultraviolet visible spectroscopy for up to 14 days of immersion in distilled water at 37ºC. Data (µg/mL) were submitted to ANOVA 1-factor/Bonferroni (α=0.05). RESULTS: Softone had a more irregular surface than Trusoft. Morphological changes were noted in both materials with increasing immersion time, particularly, in those containing drugs. Groups containing Chx and It presented extremely porous and irregular surfaces. Both materials had biexponential release kinetics. Softone leached a higher concentration of the antifungals than Trusoft (p=0.004), and chlorhexidine was released at a higher concentration than nystatin (p<0.001). CONCLUSIONS: The surface of the soft lining materials changed more significantly with the addition of Chx or It. Softone released a higher concentration of drugs than Trusoft did, guiding the future treatment of denture stomatitis.


Assuntos
Reembasadores de Dentadura , Estomatite sob Prótese , Antifúngicos , Candida albicans , Humanos , Cetoconazol , Teste de Materiais , Nistatina , Estomatite sob Prótese/tratamento farmacológico , Propriedades de Superfície
11.
J Dent ; 106: 103589, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33524431

RESUMO

OBJECTIVES: Denture soft liner is applied to relieve pain from candida-induced denture stomatitis and promote healing, but with shortage of antifungal activity and easily harbors fungi. To overcome this problem, the in-situ method was used to synthesize silver nanoparticles (AgNPs) in acrylic soft liner to obtain antifungal effects. METHODS: Acrylic soft-liner with various weight percentage of silver 2-ethylhexanoate (0%, 0.1 %, 0.2 %, 0.3 %) were prepared in 10 mm × 10 mm × 3 mm. After chemical polymerization, the diameter of AgNPs synthesized in situ and the degree of conversion of each group were measured. After 3, 7, and 14 days of storage in water, the antifungal rate (AFR) of in vitro direct contact antifungal assays and the antifungal test of non-cumulative extract solution were measured respectively. The release profiles of silver ions from the specimen within 14 days were also evaluated. RESULTS: Evenly distributed AgNPs (4.7 nm-5.3 nm) were observed, and the degree of conversion had no significant difference among these groups. The AFR increased as the silver concentration rose, while decreasing with the storage time. After 14 days of water storage, the AFR of 0.2 % and 0.3 % groups still reached 63.38 % and 75.51 %, respectively. The non-cumulative extract solution had no antifungal effect. CONCLUSIONS: Within the service life, the acrylic soft liner containing AgNPs synthesized in situ had effective control of Candida albicans through direct contact. CLINICAL SIGNIFICANCE: This study suggests that AgNPs synthesized in situ may be an effective strategy in modifying acrylic denture soft liner to treat and prevent denture stomatitis.


Assuntos
Reembasadores de Dentadura , Nanopartículas Metálicas , Antifúngicos/farmacologia , Candida albicans , Dentaduras , Prata/farmacologia
12.
J Mech Behav Biomed Mater ; 117: 104390, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33607569

RESUMO

This study aims to simulate the stress distributions of oral mucosa under different soft denture liners using the smoothed particle hydrodynamics (SPH) method. The Young's modulus and viscosity of denture liners composed of silicone (Sofreliner Super Soft and Sofreliner Tough Medium, Tokuyama Dental), acrylic (Vertex Soft, Vertex Dental), and a tissue conditioner (Visco-gel, Dentsply Sirona) were measured using a creep meter. A numerical simulation model that represents the stress distribution of oral mucosa under soft denture liners was also developed using the SPH method. The oral mucosa was divided into four regions: A) buccal border, B) buccal shelf, C) crest of residual ridge, and D) lingual border. For each region, the von Mises stress (hereafter, referred to as "Mises stress") of the oral mucosa was calculated. Based on a creep test, Sofreliner Super Soft and Sofreliner Tough Medium silicone liners showed an elastic behavior, whereas Vertex Soft acrylic liner and Visco-gel tissue conditioner showed a viscoelastic behavior. In addition, Sofreliner Super Soft and Visco-gel exhibited a large strain. The numerical simulation revealed that the mean Mises stress was the highest in region A and lowest in region D. Vertex Soft acrylic liners resulted in a statistically lower Mises stress on the oral mucosa compared to the other three soft denture liners. Different soft denture liner materials lead to different stress distributions on the oral mucosa. The acrylic soft denture liners cause a lower Mises stress on the oral mucosa than the silicon soft denture liners. This suggests that acrylic soft denture liners would be more effective for manufacturing painless dentures than silicone soft denture liners.


Assuntos
Reembasadores de Dentadura , Resinas Acrílicas , Hidrodinâmica , Teste de Materiais , Mucosa Bucal , Elastômeros de Silicone
13.
Braz. dent. sci ; 24(4): 1-11, 2021. tab, ilus
Artigo em Inglês | LILACS, BBO - Odontologia | ID: biblio-1293054

RESUMO

Objective: The present study was oriented to estimate the effect of different surface treatments on the microleakage between the soft liner and acrylic with and without the use of autoclave as disinfection method. Material and Methods: Sixty samples were split into two groups: the autoclaved groups and non-autoclaved groups. Each one subdivided into three groups: first one without any treatments as a control group; in the second group surface of the samples were treated with CO2 laser (10.6 nm wavelength for 15 seconds), and in the third group the surface was treated with sandblasting (250 µm Al2O3). All the samples exposed to thermocycling, then the microleakage test was evaluated by gauging dye penetration depth between the soft liner and acrylic disc using a digital microscope. Data analyzed statistically by One-way ANOVA and Tukey's post-hoc tests. In addition, t-test was used for comparison between two groups (P-value ≤ 0.05). Results: The maximum mean values for the microleakage were observed in the untreated group (control) followed by the group treated by CO2 laser and the lowest mean value of microleakage was related to the third group for both non-autoclaved and autoclaved groups with significant differences among them. In addition, depending on the use of autoclave, there was non-significant in all studied groups. Conclusions: There was a decrease in the microleakage when the surface treated with CO2laser and sandblast. The use of autoclave did not badly change the microleakage between the soft liner and denture base. (AU)


Objetivo: O presente estudo teve como objetivo estimar o efeito de diferentes tratamentos de superfície na microinfiltração entre o soft liner e o acrílico usando ou não a autoclve como método de desinfecção. Material e Métodos: Sessenta amostras foram divididas em dois grupos: grupo com uso da autoclave e grupo sem uso da autoclave. Cada um subdivide em três grupos: o primeiro sem nenhum tratamento como grupo controle; no segundo grupo, a superfície das amostras foi tratada com laser de CO2 (comprimento de onda de 10,6 nm por 15 segundos) e, no terceiro grupo, a superfície foi tratada com jateamento (250 µm Al2O3). Todas as amostras foram expostas à termociclagem, em seguida o teste de microinfiltração foi realizado medindo-se a profundidade de penetração do corante entre o soft liner e o disco de acrílico em microscópio digital. Os dados foram analisados estatisticamente por One-way ANOVA e testes post-hoc de Tukey. Além disso, o teste t foi usado para comparação entre dois grupos (P-valor ≤ 0,05). Resultados: Os valores médios máximos de microinfiltração foram observados no grupo não tratado (controle) seguido pelo grupo tratado com laser de CO2 e o valor médio mínimo de microinfiltração foi relacionado ao terceiro grupo para ambos os grupos não autoclavado e autoclavado com diferenças significativas entre eles. Além disso, dependendo do uso de autoclave, não houve significância em todos os grupos estudados. Conclusão: Houve diminuição da microinfiltração quando a superfície foi tratada com laser de CO2e jateamento. O uso de autoclave não alterou a microinfiltração entre o soft liner e a base da prótese (AU)


Assuntos
Abrasão Dental por Ar , Reembasadores de Dentadura , Lasers de Gás
14.
Dent Mater J ; 40(3): 573-583, 2021 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-33361658

RESUMO

The aim of this in vitro study was to evaluate the effects of incorporating fluorescent carbon nanoparticles (FCNs) on the hardness, tear, and tensile bond strength of an acrylic-based tissue conditioner and a silicone-based soft denture liner. FCNs added to an acrylic-based tissue conditioner (Viscogel, Dentsply; Group V) and a silicone-based soft denture liner (Ufigel P, Voco; Group U) were divided into subgroups according to the concentrations (Group 0: no water, Group 1: with only water, Group 2: 0.5% FCNs, Group 3: 1% FCNs and Group 4: 10% FCNs) (n=10/per group). Shore A hardness, tear, and tensile bond strength tests were performed. Significant decreases occurred in Groups U2, U3, and U4 compared to the control groups (Groups U0 and U1) in the tear and tensile bond strength test parameters (p<0.025). However, in both types of the tested materials, there were no statistically significant differences among the shore A hardness test results (p>0.025).


Assuntos
Colagem Dentária , Reembasadores de Dentadura , Nanopartículas , Resinas Acrílicas , Carbono , Bases de Dentadura , Teste de Materiais , Elastômeros de Silicone , Propriedades de Superfície , Resistência à Tração
15.
J Prosthet Dent ; 124(6): 799.e1-799.e5, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33039186

RESUMO

STATEMENT OF PROBLEM: The separation of a denture liner from the denture base can be a clinical problem. Different surface treatments to increase the bond have been evaluated, but studies comparing the effect of argon plasma and erbium-doped yttrium aluminum garnet (Er:YAG) laser on the bond between acrylic resin and a denture liner are lacking. PURPOSE: The purpose of this in vitro study was to evaluate the effect of argon plasma and Er:YAG laser treatments on the bond strengths of acrylic resin to 2 denture liners. MATERIALS AND METHODS: Heat-polymerized acrylic resin (Acron Duo) was bonded to silicone soft-liner materials (Molloplast B, n=30; Mollosil, n=30) to create control specimens (n=10), argon plasma treatment (n=10), and Er:YAG laser treatment (n=10). Silicone liners were polymerized on resin specimens. The tensile bond strength test was performed with a crosshead speed of 10 mm/min with a 10-N load until failure. Data were analyzed by using the Kruskal-Wallis test and unpaired t test (α=.05). RESULTS: The laser group showed significantly higher bond strength than the argon plasma group for both Molloplast-B (P=.001) and Mollosil (P<.001). The highest tensile bond strength values were determined in the laser-treated Molloplast-B group (1.325 ±0.119 MPa) while the lowest bond strength values were determined in the Mollosil control group (0.384 ±0.018 MPa). CONCLUSIONS: Argon plasma and Er:YAG laser applications increases the tensile bond strength between soft-liner material and resin. Er:YAG laser treatment results in higher bond strength values than treatment with argon plasma for 1 minute.


Assuntos
Colagem Dentária , Reembasadores de Dentadura , Lasers de Estado Sólido , Gases em Plasma , Resinas Acrílicas , Argônio , Bases de Dentadura , Teste de Materiais , Propriedades de Superfície , Resistência à Tração
16.
Niger J Clin Pract ; 23(9): 1266-1273, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32913167

RESUMO

Aims: This study evaluated the effect of oxygen plasma and argon plasma treatments with different application times on tensile bonding of a silicone-based denture liner to polymethylmetacrylate (PMMA). Methods: Seven groups (n = 5) were prepared and six of them treated by argon plasma or oxygen plasma with 30s, 60s, and 120s, respectively; one group was left untreated served as control. After processing of denture liner, the specimens were deflasked and stored dry for 24 h, and they were then subjected to tensile bond strength testing. Differences in tensile bond strength values were determined using one-way ANOVA (α = 0.05). Results: Highest tensile bond strengths were observed in the oxygen plasma groups, followed by untreated group and argon plasma groups in turn in order. Tensile bond strenght were increased with time for both type of plasma applications tested. Conclusion: This study suggests that the adhesion between PMMA and denture liner is improved under conditions of oxygen plasma treatment with extended exposure time rather than argon plasma treatment.


Assuntos
Coagulação com Plasma de Argônio , Colagem Dentária/métodos , Reembasadores de Dentadura , Polimetil Metacrilato/química , Silicones/química , Resistência à Tração , Argônio , Bases de Dentadura , Humanos , Teste de Materiais , Oxigênio , Propriedades de Superfície
18.
J Contemp Dent Pract ; 21(4): 353-358, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32584268

RESUMO

AIM: This study was conducted to evaluate the grape seed extract (GSE)-modified soft liner regarding surface roughness, tensile bond strength to the denture base material, and the antifungal activity. MATERIALS AND METHODS: The GSE powder was blended with the soft liner powder in ratios of 5 and 10% w/w, and three groups were employed: I, control; II, 5% w/w GSE-modified soft liner; III, 10% w/w GSE-modified soft liner. Evaluation parameters included surface roughness, tensile bond strength to the denture base material, and the antifungal activity. Changes in surface topography were evaluated by scanning electron microscopy. The statistical analysis was performed using the one-way ANOVA followed by the Tukey's test (α = 0.05). RESULTS: The 5% w/w GSE-modified soft liner showed a significant increase in surface roughness, while both ratios (5 and 10% w/w) of the modified-soft liner exhibited significant increase in tensile bond strength and antifungal activity (p < 0.05). CONCLUSION: The GSE of 10% w/w considerably enhanced the antifungal activity and tensile bond strength of the modified soft liner to the denture base material without compromising its surface roughness. CLINICAL SIGNIFICANCE: The 10% w/w GSE-modified soft liner may be a promising formulation with antifungal activity. It could inhibit fungal adherence and development of fungi-induced lesions or exacerbation of existing ones.


Assuntos
Colagem Dentária , Reembasadores de Dentadura , Extrato de Sementes de Uva , Antifúngicos , Bases de Dentadura , Teste de Materiais , Propriedades de Superfície , Resistência à Tração
19.
Arch Oral Biol ; 117: 104822, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32592931

RESUMO

OBJECTIVE: Overcoming substantial shortcomings of soft liners as physico-chemical changes and liner-biofilm-related infections remains a challenge in the rehabilitation treatment. In this study, protective non-thermal plasma (NTP) treatments were developed on the soft liner surface to improve its surface and physico-chemical properties and to reduce fungal colonization after biofilm inhibition challenge. METHODS: Resinous liner specimens (Coe-Soft) were prepared and distributed in 3 groups according to the surface treatments: (1) untreated (control); (2) treated with sulfur hexafluoride-based NTP (SF6); and (3) treated with hexamethyldisiloxane-based NTP (HMDSO). To test the NTP stability and their protective and antimicrobial effect on the liner surface over time, the morphology, chemical composition, roughness, water contact angle, shore A hardness, sorption and solubility were evaluated before and after the specimens were exposed to dual-species biofilm of Candida albicans and Streptococcus oralis for 14 days. Colony forming units and biofilm structure were assessed. Data were submitted to ANOVA and Tukey tests (α = 0.05). RESULTS: Both treatments modified the surface morphology, increased hydrophobicity and roughness of the liner, and were effective to reduce C. albicans adhesion without affecting the commensal health-associated S. oralis. HMDSO presented chemical stability and lower hardness in both periods, whereas SF6 exhibited higher initial hardness than control and the highest sorption; contrarily, similar solubility was noted for all groups. CONCLUSION: HMDSO-based film showed improved physico-chemical properties and inhibited C. albicans biofilm. Thus, it has potential for use to control candida-related stomatitis and improve liner's stability even after being exposed to biofilm inhibition challenge.


Assuntos
Anti-Infecciosos , Biofilmes , Reembasadores de Dentadura , Gases em Plasma , Anti-Infecciosos/farmacologia , Candida albicans , Teste de Materiais , Gases em Plasma/farmacologia , Streptococcus oralis , Propriedades de Superfície
20.
Indian J Dent Res ; 31(2): 282-290, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32436910

RESUMO

Objective: This study evaluated the effect of chemical disinfection and microwave irradiation on the surface hardness and roughness of two commercially available hard relining materials (Ufi Gel hard, GC Kooliner) and one denture base resin (Trevalon). Materials and Methods: A total of 72 specimens (n = 24) were divided into four groups. C: Not disinfected, Cl: disinfected with 4% chlorhexidine solution, Gl: disinfected with 2% glutaraldehyde solution, Mw: disinfected with microwave irradiation (650 W; 6 min). Hardness and roughness measurements were made after polymerisation, 1st day, 14th day and 28th day. Results: Ufi Gel hard showed an increased roughness after 1st day (P = 0.021) following chemical disinfection and GC Kooliner showed similar results after 14th day (P < 0.05). Microwave irradiation showed a significant increase in surface roughness value after 1st day (P < 0.05) for both Ufi Gel hard and GC Kooliner. Hardness of both Ufi Gel (12.131 to 7.333 VHN) and Kooliner (9.133 to 5.276 VHN) was significantly reduced by chemical disinfection, while microwave irradiation resulted in an increased surface hardness of Kooliner (from 9.126 to 12.713 VHN) and Ufi Gel hard (from 11.698 to 14.940VHN). Results for Trevalon were not significant for both the disinfection methods. Conclusions: Microwave irradiation increased the surface roughness and hardness of Ufi Gel hard and Kooliner, while chemical disinfection resulted in a decreased hardness and increased roughness of both hard relining materials. There was no effect of either of the disinfection methods on Trevalon.


Assuntos
Bases de Dentadura , Reembasadores de Dentadura , Desinfecção , Dureza , Teste de Materiais , Micro-Ondas , Propriedades de Superfície
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