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1.
J Appl Oral Sci ; 28: e20200639, 2021 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-33656098

RESUMEN

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.


Asunto(s)
Alineadores Dentales , Estomatitis Subprotética , Antifúngicos , Candida albicans , Humanos , Cetoconazol , Ensayo de Materiales , Nistatina , Estomatitis Subprotética/tratamiento farmacológico , Propiedades de Superficie
2.
Niger J Clin Pract ; 23(9): 1266-1273, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32913167

RESUMEN

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.


Asunto(s)
Coagulación con Plasma de Argón , Recubrimiento Dental Adhesivo/métodos , Alineadores Dentales , Polimetil Metacrilato/química , Siliconas/química , Resistencia a la Tracción , Argón , Bases para Dentadura , Humanos , Ensayo de Materiales , Oxígeno , Propiedades de Superficie
4.
Arch Oral Biol ; 117: 104822, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32592931

RESUMEN

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.


Asunto(s)
Antiinfecciosos , Biopelículas , Alineadores Dentales , Gases em Plasma , Antiinfecciosos/farmacología , Candida albicans , Ensayo de Materiales , Gases em Plasma/farmacología , Streptococcus oralis , Propiedades de Superficie
5.
J Contemp Dent Pract ; 21(4): 353-358, 2020 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-32584268

RESUMEN

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.


Asunto(s)
Recubrimiento Dental Adhesivo , Alineadores Dentales , Extracto de Semillas de Uva , Antifúngicos , Bases para Dentadura , Ensayo de Materiales , Propiedades de Superficie , Resistencia a la Tracción
6.
Indian J Dent Res ; 31(2): 282-290, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32436910

RESUMEN

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.


Asunto(s)
Bases para Dentadura , Alineadores Dentales , Desinfección , Dureza , Ensayo de Materiales , Microondas , Propiedades de Superficie
7.
J Prosthodont Res ; 64(4): 417-423, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32061571

RESUMEN

PURPOSE: This randomized controlled trial aimed to study the effects of lining mandibular complete dentures with silicone-based resilient denture liners, especially with respect to sensation. METHODS: The trial included completely edentulous patients who were willing to fabricate new set of complete denture. A random permuted block method (block size: 4) was used to assign participants to one of the following groups: mandibular conventional denture (CD) group or mandibular denture with resilient denture liner (RD) group. The outcomes were evaluated using both, objective measures (current perception threshold (CPT) and pain threshold (PT)) for external stimuli measured using the Neurometer CPT® and subjective measures (physical pain and psychological discomfort measured using the Japanese version of Oral Health Impact Profile for Edentulous patients-OHIP-EDENT-J). The outcomes were measured twice, at immediately after completion of denture adjustments (first measurement), and 3 months after the completion of denture adjustments (second measurement). All outcomes were analyzed using the Student t-test. A p-value of <0.05 was considered statistically significant. RESULTS: CPT was significantly higher with RD than CD only at second measurement with frequency level of 2000 Hz and 5 Hz. The pain thresholds were significantly higher in the RD group than the CD group. The physical pain and psychological discomfort scores were significantly lower in the RD group than in the CD group. CONCLUSION: This study concludes that edentulous patients wearing mandibular complete dentures with silicone-based resilient denture liners dull perception mandibular ridge mucosa and felt less pain than those without the liners.


Asunto(s)
Alineadores Dentales , Resinas Acrílicas , Dentadura Completa , Dentadura Completa Inferior , Humanos , Dolor , Siliconas
8.
Odontology ; 108(3): 366-375, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31807949

RESUMEN

Soft denture liners and tissue conditioners are widely used for the denture patients to cushion masticatory force and condition abused tissues, respectively. This study assessed methods for the evaluation of the viscoelasticity and glass transition temperature (Tg) of the silicone permanent soft liner, acrylic permanent soft liner, and tissue conditioner. Three rheological parameters of storage modulus (E'), loss modulus (E''), and loss tangent ([Formula: see text]), Tg, and hardness were determined using dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and the Shore A0 hardness test. Five specimens were measured for each material. The time-temperature superposition principle was applied to produce master curves of E', E'', and [Formula: see text] for the tested materials at a reference temperature of 37 °C. The acrylic permanent soft liner and tissue conditioner exhibited viscoelastic behavior and sensitivity to frequency, especially at lower frequencies. The silicone permanent soft liner showed elastic behavior and was frequency-independent. Tg for the acrylic permanent soft liner was higher than that for the tissue conditioner, which in turn was higher than that for the silicone permanent soft liner for both DMA and DSC. In DMA, a higher frequency led to higher Tg values. A positive linear relationship was found between Shore A0 hardness and E' values, but not E'' and [Formula: see text] values. Shore hardness reflects elasticity, but not viscosity. The results of the present study can be used to improve methods for evaluating the viscoelasticity and Tg of soft denture liners and tissue conditioners.


Asunto(s)
Alineadores Dentales , Resinas Acrílicas , Elasticidad , Dureza , Humanos , Ensayo de Materiales , Elastómeros de Silicona , Temperatura , Temperatura de Transición
9.
J Prosthodont Res ; 64(4): 373-379, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31787576

RESUMEN

PURPOSE: This study aims to investigate the effect of mechanical and chemical cleaning on the surface roughness of silicone soft relining materials. METHODS: We selected silicone soft relining materials with the highest (Soft) and lowest (Supersoft) Shore A hardness. In the abrasion test, specimens were cleaned 50,000 times using a kitchen sponge (Sponge), a soft (Soft brush) or hard (Hard brush) denture brush, or stored in water (No cleaning). In the immersion test, specimens were immersed in either water (Water), neutral peroxide denture cleanser (Neutral), alkaline peroxide denture cleanser (Alkaline), or hypochlorite denture cleanser (Hypochlorite) for 1440 h. Surface roughness of the arithmetic mean height of the surface (Sa) and maximum height (Sz) were measured before and after the tests. Data were analyzed using the Kruskal-Wallis and Mann-Whitney U tests. RESULTS: In the abrasion test, significant differences were observed for Sa and Sz with Soft relining materials, but not for No cleaning and Sponge. In the immersion test, significant differences were observed for Sa and Sz with Soft relining materials, but not between Water and Neutral or Water and Alkaline. Significant differences were observed with Supersoft, except between Water and Neutral or Water and Alkaline for Sa and between Water and Neutral for Sz. CONCLUSIONS: Mechanical cleaning using a sponge did not increase the surface roughness of the material with a high Shore A hardness. Furthermore, neutral peroxide denture cleanser did not increase the roughness of materials with high and low Shore A hardness.


Asunto(s)
Alineadores Dentales , Siliconas , Limpiadores de Dentadura , Ensayo de Materiales , Propiedades de Superficie
10.
J Prosthodont Res ; 64(4): 380-383, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31787578

RESUMEN

PURPOSE: The purpose of this study was to compare the adhesiveness of chewing gum to hard and soft denture base materials to investigate food retention associated with the basal surface of the denture. METHODS: Test specimens were fabricated using acrylic resin[Re], cobalt-chromium alloy[Co], zirconia[Zr], silicone soft relining material[SS], and acrylic soft relining material[AS]. Samples were set on a top-and-bottom pair lifting platform equipped with a digital force gauge. The experimenter chewed 3.0 g of chewing gum for 5 min. After surface saliva was wiped off, the chewing gum was placed on the lower test fragment and compressed until the distance between the upper and lower test fragments decreased to 1 mm. The upper test fragment was pulled at a crosshead speed of 100 mm/min. Adhesiveness was measured under dry conditions, and under wet conditions with inter-positioned artificial saliva. RESULTS: Under dry conditions, the adhesive strength was 17.04 ±â€¯1.99 N for Re, 12.88 ±â€¯2.20 N for Co, 3.80 ±â€¯1.03 N for Zr, 5.76 ±â€¯1.41 N for SS, and 12.54 ±â€¯2.44 N for AS. Under wet conditions, the adhesive strength was 5.26 ±â€¯1.64 N for Re, 0.96 ±â€¯0.21 N for Co, 3.32 ±â€¯0.40 N for Zr, 5.20 ±â€¯1.35 N for SS, and 6.78 ±â€¯1.97 N for AS. CONCLUSIONS: Among the hard denture base materials, zirconia recorded low adhesiveness and Re recorded high adhesiveness under both wet and dry conditions. The adhesiveness of Co was low under wet conditions but high under dry conditions. Among the soft denture base materials, SS under dry conditions recorded lower adhesiveness than that of AS. The adhesiveness of SS was low under both wet and dry conditions.


Asunto(s)
Recubrimiento Dental Adhesivo , Alineadores Dentales , Adhesividad , Goma de Mascar , Bases para Dentadura , Ensayo de Materiales , Propiedades de Superficie , Resistencia a la Tracción
11.
Int J Prosthodont ; 33(1): 56-62, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31860914

RESUMEN

PURPOSE: To compare the bond strengths of three types of permanent silicone and acrylic resin soft liners to the denture-base acrylic resin by employing both synchronous and asynchronous processing methods and different surface treatments. MATERIALS AND METHODS: A total of 198 cylindrical samples were fabricated from denture-base acrylic resin and a 3-mm soft liner. Surface treatments of the samples were classified into five groups (n = 33 each): no treatment (control); erbium:yttrium-aluminum-garnet (Er:YAG) laser; grit-blasting with 150-µm particles; monomer application; and phosphoric acid application. In addition, synchronous processing (n = 33) of the acrylic resin denture base and the soft liner was performed. Each group was divided into three subgroups (n = 11 each) based on the type of soft liner: Group M (Molloplast-B [silicone]), Group P (PermaFlex [silicone]), and Group A (AcroSoft [acrylic resin]). The samples were processed and thermocycled for 5,000 cycles between 5°C and 55°C, and the tensile strength test was then performed. The maximum tensile strength to failure and the type of failure were recorded, and Dunn statistical analysis and Kruskal-Wallis tests were used for comparison of the groups. The surface treatments were assessed using scanning electron microscopy. RESULTS: Irrespective of the method of processing or surface treatment, Group A had a significantly higher bond strength (8.1 ± 1.1 MPa) than the other two soft liners (Group M: 1.9 ± 0.3 MPa, Group P: 1.1 ± 0.2 MPa; P < .001). Moreover, in Group A, the synchronous processing method produced a significantly higher tensile strength (P < .001), while in Group P (P = .112) and Group M (P = .993), synchronous processing had no significant effect on bond strength. Bond strength after surface treatment in Group M was lowest after grit blasting (0.7 ± 0.2 MPa) and highest after monomer application (3.1 ± 0.5 MPa) (P < .001). The same was observed for Group P in grit blasting (0.5 ± 0.2 MPa) and monomer application (2.1 ± 0.3 MPa) (P < .001). For Group A, grit blasting (4.8 ± 0.7 MPa) was also the lowest and the monomer application (8.1 ± 0.8 MPa) the highest ± (P < .001), while the bond strength resulting from the synchronous processing method was higher than that of the other methods (14.7 ± 2.1 MPa). CONCLUSION: Within the limitations of this in vitro study, the acrylic resin soft liner showed the best bond strength. In all types of soft liners, surface treatment with the monomer resulted in higher bond strengths. Synchronous processing exhibited a significantly higher bond strength for the acrylic resin soft liner, but not for the silicone soft liners.


Asunto(s)
Recubrimiento Dental Adhesivo , Alineadores Dentales , Resinas Acrílicas , Bases para Dentadura , Ensayo de Materiales , Propiedades de Superficie , Resistencia a la Tracción
12.
J Prosthet Dent ; 123(6): 800-806.e6, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31703921

RESUMEN

STATEMENT OF PROBLEM: Occasional debonding between soft liners and denture base resin is common and limits the longevity of a relined prosthesis. PURPOSE: The purpose of this systematic review was to compare the bond strength of commercially available soft liners with that of polymethyl methacrylate (PMMA) and urethane dimethacrylate (UDMA) denture base resins after different surface treatments and thermocycling. MATERIAL AND METHODS: Searches were performed by 2 independent reviewers in the MEDLINE/PubMed and Cochrane Library databases from January 1990 to December 2018 to identify published journal articles related to this subject. Subsequently, a hand search was also carried out for all the articles mentioned in the references of the identified full articles. RESULTS: A total of 61 articles were initially identified through database searches by the 2 reviewers. Twenty-four of the 61 articles met the inclusion criteria for qualitative analysis. Four of 6 articles showed that laser pretreatment of denture base resins increased their bonding to soft liners. Seven of 8 articles concluded that airborne-particle abrasion caused deterioration of the bonding between the liner and denture base resin. Four of 6 studies showed that acid etching, silica coating, primer or monomer application, and immersion in acetone or isobutyl methacrylate (iBMA) resulted in improved bond strengths between the liner and resin. One study reported that oxygen plasma treatment also resulted in improved bond strengths. Seven of 8 articles concluded that thermocycling resulted in decreased bond strengths. CONCLUSIONS: Laser treatment, oxygen plasma pretreatment, primer or monomer application, and immersion in acetone or iBMA resulted in improved bonding of the denture base resin to soft liners. However, airborne-particle abrasion and thermocycling resulted in deterioration of the bond.


Asunto(s)
Recubrimiento Dental Adhesivo , Alineadores Dentales , Resinas Acrílicas , Bases para Dentadura , Ensayo de Materiales , Polimetil Metacrilato , Elastómeros de Silicona , Propiedades de Superficie , Resistencia a la Tracción
13.
J Prosthet Dent ; 123(4): 630-634, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31383531

RESUMEN

STATEMENT OF PROBLEM: Changes in the intraoral condition immediately after implant placement and in patients using fixed prosthetic appliances with implant abutments cause problems that require the use of an easily adjustable implant-supported overdenture system. PURPOSE: The purpose of this in vitro study was to develop a simulated implant-supported overdenture attachment system by using healing screws for the patrix and a silicone resilient denture liner for the matrix and to investigate the initial retention force, time-course changes, and allowable range of the angle between attachments. MATERIAL AND METHODS: Tests on the retention force and allowable range of the angle were performed. Attachments using tissue-level healing screws (height: 2.0 and 3.0 mm) for the patrix and a silicone resilient denture liner for the matrix were prepared. In the retention force measurement test, the frequency of insertion and removal was set at 3 per day to simulate a 4-month relief period. The joined attachment model was pulled apart, and the maximum traction (N) required to remove it was defined as the retention force. The retention force was measured every 90 times (representing the number of insertions and removals per month). To test the allowable angle range, 2 patrices were used. The angle between the 2 patrices was set at 0, 10, 20, and 30 degrees, and the angular limit for joining with the matrix was measured. The initial retention force of the healing screw attachments was compared with that of a polymeric O-ring by using 1-way layout ANOVA followed by the Bonferroni test (α=.05). To analyze time-course changes in the 2 types of healing screw attachments, the retention force before insertion and removal was compared with that after repeated insertions and removals for each simulated period using 1-way layout ANOVA followed by the Dunnett test (α=.05). RESULTS: The initial retention force of the 2.0- and 3.0-mm healing screws was 2.4 ±0.1 and 2.6 ±0.2 N. After repeating insertions and removals to simulate use for 4 months, the retention force of the 2.0- and 3.0-mm healing screws was 1.8 ±0.2 and 2.2 ±0.1 N, respectively, both showing significant differences from the initial retention force (P<.05). The allowable angle range test revealed that insertion and removal of the healing screws was possible up to 30 degrees. CONCLUSIONS: Under the conditions of this in vitro study, repeated insertion and removal attenuated the retention force but was still equivalent to the retention force of the O-ring. The allowable range of the angle between patrices for insertion and removal was up to 30 degrees.


Asunto(s)
Implantes Dentales , Alineadores Dentales , Tornillos Óseos , Prótesis Dental de Soporte Implantado , Análisis del Estrés Dental , Retención de Dentadura , Prótesis de Recubrimiento , Humanos , Siliconas
14.
Shanghai Kou Qiang Yi Xue ; 28(4): 378-383, 2019 Aug.
Artículo en Chino | MEDLINE | ID: mdl-31792477

RESUMEN

PURPOSE: To prepare a soft lining material with high elastic on the basis of excellent characteristics of Eucommia ulmoides gum, and explore its basic physical performance and cytotoxity. METHODS: Basic formula was used based on the existing formula of elastic Eucommia ulmoides gum and medical rubber, then hardness, tensile strength and elongation at break were investigated to determine the final formula of the material, named Eucommia ulmoides gum composite soft denture liner. L929 mouse fibroblasts cultured in vitro were used to detect the toxic effects of 50% of leaching solution released from three kinds of denture soft lining materials by MTT assay. Statistical analysis was performed using SPSS16.0 software package. RESULTS: The kinds and blending proportion of rubber matrix had significant impact on mechanical properties of Eucommia ulmoides gum composite soft denture liner, the addition of Eucommia ulmoides gum significantly increased the hardness, tensile strength and elongation at break of the butadiene rubber. MTT assay showed Eucommia ulmoides gum composite soft denture liner did not have cytotoxicity on L929 mouse fibroblasts. The toxicity levels of 5 groups of Eucommia ulmoides gum composite soft denture liner in the 2nd, 4th, 7th day were maintained in the first stage, only 70:30 group reached the second stage on the 7th day. The cell relative appreciation rate of Silagum and 5 groups of Eucommia ulmoides gum composite soft denture liner in 2nd, 4th, 7th day were significantly higher than that in the self-curing acrylic soft lining material (P<0.05). CONCLUSIONS: Eucommia ulmoides gum and butadiene rubber blend ratio of 70:30, adding appropriate amount of zinc oxide, magnesium, stearic acid, sublimed sulfur, CZ, antioxidants, can get optimum mechanical properties. Eucommia ulmoides gum composite soft denture liner has no effect on L929 fibroblasts proliferation, indicating good biocompatibility.


Asunto(s)
Alineadores Dentales , Eucommiaceae , Animales , Materiales Dentales , Bases para Dentadura , Dureza , Ensayo de Materiales , Ratones , Resistencia a la Tracción
15.
Sci Rep ; 9(1): 11889, 2019 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-31417116

RESUMEN

The objective of this in vitro study was to investigate the effect of nanostructured silver vanadate decorated with silver nanoparticles (AgVO3) on antimicrobial activity, hardness, roughness, and adhesion of a soft denture liner. The antimicrobial efficacy of the Trusoft (Boswoth) liner incorporated with different concentrations of AgVO3 against Enterococcus faecalis, Pseudomonas aeruginosa, Candida albicans, and Staphyloccocus aureus (n = 5) was evaluated by the agar diffusion method. Roughness, hardness, and adhesion properties were also evaluated. The data were analyzed by analysis of variance (ANOVA) and Tukey's multiple comparison test with significance at the p < 0.05 level. At concentrations of 1 and 2.5%, AgVO3 incorporation was effective only against E. faecalis, and at 5 and 10%, against E. faecalis, P. aeruginosa, and C. albicans. None of the concentrations was effective against S. aureus. A decrease in hardness was found for the 1, 2.5, and 10% AgVO3 concentrations (p < 0.001) and at 5%, hardness was not affected. None of the concentrations affected the roughness of the material. A significant increase in tensile values was observed between the liner and heat-curing acrylic resin for 2.5% (p < 0.001) and 10% (p = 0.042) concentrations. AgVO3 incorporation to a soft denture liner promoted antimicrobial activity against E. faecalis, P. aeruginosa, and C. albicans without affecting roughness, maintaining the hardness properties recommended for soft and extra soft liners, and improving the adhesion between the liner and the acrylic resin used for dentures.


Asunto(s)
Antiinfecciosos/química , Antiinfecciosos/farmacología , Alineadores Dentales , Nanopartículas del Metal/química , Compuestos de Plata/química , Vanadatos/química , Fenómenos Químicos , Nanopartículas del Metal/ultraestructura , Pruebas de Sensibilidad Microbiana , Compuestos de Plata/síntesis química , Espectroscopía Infrarroja por Transformada de Fourier , Vanadatos/síntesis química , Difracción de Rayos X
16.
Braz Dent J ; 30(3): 252-258, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31166393

RESUMEN

The disadvantage of liners materials is the difficulty of biofilm control. It was compared an experimental dentifrice contained Ricinus communis, with commercials dentifrices as antibiofilm activity against microorganisms on denture liner. Six hundred specimens were distributed in 5 groups (n=18/ microorganism): water; experimental dentifrice; specific dentifrice for denture and two conventional dentifrices against C. albicans; C. glabrata; S. mutans; S. aureus; E. coli. Each group had a negative (n=5; without contamination) and positive control (n=15/ microorganism; without cleaning). The antibiofilm activity was evaluated by the method of biofilm formation in triplicate. The specimens were contaminated in a standard way and incubated. After that, manual brushing was performed (60 s), washed with PBS, immersed in liquid culture medium for resuspension and sowing in solid medium. The results (mean of triplicates) were expressed in CFU/mL. The data was submitted to Shapiro-Wilk, ANOVA and Tukey test (p<0.05). The specific dentifrice (1.27±1.20) was the most effective against S. mutans, followed by conventional (Trihydral, 3.13±0.88; Colgate, 2.16±2.02) and experimental (3.81±1.37) dentifrices, which were similar to each other (p=0.008). All of them were different from water (4.79±1.42). The specific (0.21±0.21) and experimental (0.36±0.25) dentifrices were similar against S. aureus, with a higher mean of CFU when compared to conventional (Colgate, 0.06±0.13), which was more efficient (p=0.000). For C. albicans, C. glabrata and E. coli, all dentifrices were similar to water (p=0.186). It was concluded, that the experimental dentifrice was effective against S. aureus and had not efficacy against Candida spp.; S. mutans; E. coli, as occurred with the commercials dentifrices.


Asunto(s)
Dentífricos , Alineadores Dentales , Escherichia coli , Ricinus , Staphylococcus aureus , Cepillado Dental
17.
ScientificWorldJournal ; 2019: 6913080, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30940994

RESUMEN

Purpose: The objective of this systematic review is to compare results concerning the properties of adhesion, roughness, and hardness of dental liners obtained in the last ten years. Methods: Searches on the databases LILACS, PubMed/Medline, Web of Science, and Cochrane Database of Systematic Reviews were supplemented with manual searches conducted between February and April of 2018. The inclusion criteria included experimental in vitro and in vivo, clinical, and laboratory studies on resilient and/or hard liners, assessment of hardness, roughness, and/or adhesion to the denture base, and physical/mechanical changes resulting from the disinfection process and changes in liners' composition or application. Results: A total of 406 articles were identified and, from those, 44 are discussed. Twenty-four studies examined the bond strength, 13 surface roughness, and 19 the hardness. Of these 44 studies, 12 evaluated more than one property. Different substances were used in the attempt to improve adhesion. Considering roughness and hardness, the benefits of sealants have been tested, and the changes resulting from antimicrobial agents' incorporation have been assessed. Conclusion: Adhesion to the prosthesis base is improved with surface treatments. Rough surfaces and changes in hardness compromise the material's serviceability.


Asunto(s)
Alineadores Dentales/normas , Ensayo de Materiales , Propiedades de Superficie , Adhesividad , Materiales Dentales/normas , Alineadores Dentales/microbiología , Desinfección/métodos , Dureza , Humanos , Estrés Mecánico
18.
J Prosthet Dent ; 121(1): 135-142, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30646999

RESUMEN

STATEMENT OF PROBLEM: Antifungal agents incorporated into interim denture resilient liners have been suggested as an adjunct treatment for denture stomatitis (DS). However, before applying this protocol to humans, biocompatibility analysis of such drugs in animal models is required. PURPOSE: The purpose of this animal study was to evaluate the in vivo biocompatibility of an interim resilient liner modified with minimum inhibitory concentrations (MICs) of antifungal drugs for Candida albicans biofilm. MATERIAL AND METHODS: Sixty Wistar rats were divided into 6 groups (n=5): PC=positive control/no protocol; IOD (intraoral device)=rats using an acrylic resin palatal device (PD); Tru=rats using a PD relined with Trusoft; and Ny (nystatin), Chx (chlorhexidine diacetate), and Ke (ketoconazole) groups=rats using a PD relined with Trusoft + drug MICs. The rats were sacrificed at 7 or 14 days of trial. Histopathological qualitative analysis was performed by comparing photomicrographs of histological sections of the intermolar region. Morphological changes in the epithelium and keratin were quantitatively analyzed by computerized planimetry, and data were analyzed by using 2-way ANOVA and the Tukey HSD test (α=.05). RESULTS: Quantitative analysis showed that only PD containing Ke significantly decreased the thickness and area of the keratin compared with the other groups (P<.001), which showed no differences between each other (P>.05). These results agreed with those of qualitative analysis. CONCLUSIONS: Incorporation of MICs of Ny and Chx in Trusoft did not induce histopathological changes in the rat palatal mucosa, suggesting the in vivo biocompatibility of this DS treatment.


Asunto(s)
Antifúngicos/administración & dosificación , Candida albicans/efectos de los fármacos , Alineadores Dentales , Mucosa Bucal/efectos de los fármacos , Resinas Acrílicas , Análisis de Varianza , Animales , Biopelículas/efectos de los fármacos , Clorhexidina/administración & dosificación , Queratinas/efectos de los fármacos , Cetoconazol/administración & dosificación , Ensayo de Materiales , Pruebas de Sensibilidad Microbiana , Mucosa Bucal/citología , Nistatina/administración & dosificación , Ratas , Ratas Wistar
19.
Indian J Dent Res ; 30(6): 920-926, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31939372

RESUMEN

Background: Immersion-type denture cleansers are commonly used for denture hygiene maintenance. Hence, it is crucial to investigate the effect of denture cleansing solutions on bond strength between direct reline materials and denture base resin. Aims: This in vitro study aimed to determine the effect of denture cleansers on bond strength between direct hard reline materials and denture base resin. Materials and Methods: Cylindrical columns of hard-liners (Hard GC Reline, TDV Cold Liner Rebase, Tokuyama Rebase II Fast) were bonded to heat-polymerized denture base resin. A total of fifty specimens were fabricated for each reline material and divided into five groups (n = 10): Group I (control): No solution was used; Group II: Specimens were stored in distilled water for 60 days; Groups III, IV, and V: Specimens were stored in distilled water for 60 days with daily immersion in either sodium hypochlorite, calgon + sodium hypochlorite, or dentipur tablet for 5 min. The shear bond strength was examined at a cross-head speed of 1 mm/min. Failure mode was evaluated by stereomicroscope. Statistical Analysis: Data were analyzed by two-way ANOVA and Chi-square test (α=0.05). Results: The results showed no significant interaction between the direct hard-liners and denture cleansers (P = 0.119). Hard GC Reline had the highest bond strength, followed by Tokuyama Rebase II Fast, and then, TDV Cold Liner Rebase. No significant difference existed in bond strength between samples immersed in water and cleansers or between the cleansers themselves. Hard GC Reline had more mixed failure mode compared to TDV Cold Liner Rebase and Tokuyama Rebase II Fast. There was a significant correlation between mixed mode of failure and higher values of bond strength (P = 0.008). Conclusions: Within the limitations of the present study, denture cleansing solutions could not significantly influence the bond strength between hard direct liners and denture base resin.


Asunto(s)
Recubrimiento Dental Adhesivo , Alineadores Dentales , Resinas Acrílicas , Bases para Dentadura , Limpiadores de Dentadura , Rebasado de Dentaduras , Calor , Ensayo de Materiales
20.
J Prosthodont ; 28(2): e857-e862, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29235702

RESUMEN

PURPOSE: To evaluate the effect of experimental (Ricinus communis) and commercial dentifrices used for denture cleaning on abrasiveness (gravimetric method; roughness), hardness, and color stability of a resilient relining material. MATERIALS AND METHODS: Sixty circular (15 × 3 mm) specimens were distributed into four groups: C (control; brushing with water); CO (brushing with Colgate - for natural teeth); CB (brushing with Corega Brite - for complete dentures); RC (brushing with experimental dentifrice). Brushing was performed in a toothbrushing machine with a soft brush and a dentifrice suspension for 50 minutes, calculated to correspond to 1 year of regular brushing. Variables were measured initially and after the trial period. For the gravimetric method, the difference in mass was considered. The surface roughness was measured by a rugosimeter, and the hardness test was performed by a Shore A durometer. Color changes (ΔE; CIE L*a*b* and NBS systems) were measured by a portable spectrophotometer. Results were analyzed by ANOVA/Tukey's test (α = 0.05). RESULTS: The largest mass variation (µg; p < 0.0001) occurred in C (-6.21 ± 3.18). Concerning roughness, CB (0.26 ± 0.04) showed the lowest value, followed by RC (0.29 ± 0.08) and CO (0.34 ± 0.24) (p < 0.0001). Group C produced the greatest surface roughness (0.72 ± 0.25). Hardness values decreased after brushing with water (p = 0.014). No significant differences were found among RC (50.31 ± 1.03), CO (49.11 ± 1.31), CB (49.17 ± 1.23), and C (48.02 ± 1.26). Color stability was similar in all groups (p = 0.135; C: 2.3 ± 0.77; CO: 2.6 ± 0.54; CB: 2.2 ± 0.44; RC: 2.9 ± 1.56). CONCLUSIONS: The use of experimental dentifrice could be indicated, as it showed similar results to the specific dentifrice, keeping the resilient material properties within acceptable values.


Asunto(s)
Dentífricos/química , Limpiadores de Dentadura/química , Alineadores Dentales , Cepillado Dental , Color , Dureza , Técnicas In Vitro , Ensayo de Materiales , Ricinus , Propiedades de Superficie
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