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Journal of Indian Prosthodontic Society Sep 2013Resilient liners when used intelligently are an excellent adjunct in removable prosthodontics. However, currently they have to be best considered as temporary expedients... (Review)
Review
Resilient liners when used intelligently are an excellent adjunct in removable prosthodontics. However, currently they have to be best considered as temporary expedients because none of the advocated permanent liners have life expectancy comparable to resin denture base. This article reviews the literature regarding their composition, functions, gelation characteristics, bond strength and influence on denture bases. It also presents their drawbacks and attempts made to extend their longevity. A Medline search was completed for the period from 1986 to 2007, along with a manual search, to identify pertinent English peer-reviewed articles and textbooks.
PubMed: 24431729
DOI: 10.1007/s13191-012-0143-8 -
BMC Oral Health Dec 2022Studies on the antifungal activity, flexural strength, Vickers hardness, and intaglio surface trueness of three-dimensionally printed (3DP) denture bases with...
Antifungal activity, mechanical properties, and accuracy of three-dimensionally printed denture base with microencapsulated phytochemicals on varying post-polymerization time.
BACKGROUND
Studies on the antifungal activity, flexural strength, Vickers hardness, and intaglio surface trueness of three-dimensionally printed (3DP) denture bases with microencapsulated phytochemicals with respect to changes in post-polymerization time (PPT) are lacking.
METHODS
Specimens of various shapes and dimensions were fabricated with a 3DP denture base resin mixed with 5 wt% phytoncide-filled microcapsules. Each specimen was subjected to different PPT protocols of 5, 10, 20, and 30 min. Specimens without microcapsules with 5-min PPT were used as the negative control group. Cell colonies were counted to evaluate antifungal activity. Three-point bending and Vickers hardness tests were performed to measure the flexural strengths and hardness of the specimens. Fourier-transform infrared spectrometry was used to inspect the degree of conversion (DC). The intaglio surface trueness was measured using root-mean-square estimates calculated by superimposition analysis. A non-parametric Kruskal-Wallis test or one-way analysis of variance was performed (α = 0.05).
RESULTS
The specimens with microcapsules and 10-min PPT showed the highest antifungal activity among the tested groups. Compared with the positive control group (5-min PPT), the specimens with PPTs of 10 min or longer showed significantly higher mean flexural strength, higher DC, greater hardness, and better trueness (all, P < 0.05). Except for the difference in antifungal activity, no statistically significant differences were detected between the specimens subjected to 10-, 20-, and 30-min PPT.
CONCLUSION
The 3DP denture base filled with microencapsulated phytoncide showed different antifungal activity and physical properties on changing PPT. The 3DP denture base containing phytoncide-filled microcapsules at 5 wt% concentration and subjected to 10-min PPT exhibited sufficient antifungal activity as well as mechanical properties and accuracy within clinical acceptance.
Topics: Humans; Denture Bases; Antifungal Agents; Polymerization; Capsules; Surface Properties; Printing, Three-Dimensional; Phytochemicals; Materials Testing
PubMed: 36522725
DOI: 10.1186/s12903-022-02654-9 -
The Journal of Advanced Prosthodontics Dec 2017This laboratory study aimed to investigate the effect of doping an acrylic denture base resin material with nanoparticles of ZnO, CaO, and TiO on biofilm formation.
PURPOSE
This laboratory study aimed to investigate the effect of doping an acrylic denture base resin material with nanoparticles of ZnO, CaO, and TiO on biofilm formation.
MATERIALS AND METHODS
Standardized specimens of a commercially available cold-curing acrylic denture base resin material were doped with 0.1, 0.2, 0.4, or 0.8 wt% commercially available ZnO, CaO, and TiO nanopowder. Energy dispersive X-ray spectroscopy (EDX) was used to identify the availability of the nanoparticles on the surface of the modified specimens. Surface roughness was determined by employing a profilometric approach; biofilm formation was simulated using a monospecies biofilm model and a multispecies biofilm model including , , and . Relative viable biomass was determined after 20 hours and 44 hours using a MTT-based approach.
RESULTS
No statistically significant disparities were identified among the various materials regarding surface roughness and relative viable biomass.
CONCLUSION
The results indicate that doping denture base resin materials with commercially available ZnO, CaO, or TiO nanopowders do not inhibit biofilm formation on their surface. Further studies might address the impact of varying particle sizes as well as increasing the fraction of nanoparticles mixed into the acrylic resin matrix.
PubMed: 29279769
DOI: 10.4047/jap.2017.9.6.482 -
Journal of Applied Oral Science :... Jun 2018While the combined effect of microwave irradiation with cleansing solutions on denture base materials has been investigated, the effects of only using microwave...
INTRODUCTION
While the combined effect of microwave irradiation with cleansing solutions on denture base materials has been investigated, the effects of only using microwave irradiation and, more importantly, in a long-term basis, was not studied yet.
OBJECTIVE
The purpose of this study was to evaluate the effect of a long-term repeated microwaving on the dimensional, color and translucency stability of acrylic and polyamide denture base materials.
MATERIAL AND METHODS
Thirty two specimens (32 mm x 10 mm x 2.5 mm) from polyamide (Valplast) and PMMA (Vertex Rapid Simplified) denture base materials were made. Eight specimens from each material were immersed in distilled water (control) and 8 were subjected to microwave exposure at 450 W for 3 minutes for a period simulating 224 days of daily disinfection. Linear dimension, color change (ΔE*) and translucency parameter (TP) were measured at baseline and after certain intervals up to 224 cycles of immersion, using a digital calliper and a portable colorimeter. The results were analysed using two-way repeated measures ANOVA to estimate possible differences among predetermined cycles and material type. Regression analysis was also performed to estimate the trend of changes with time. Statistical evaluations performed at a significance level of 5%.
RESULTS
Data analysis showed significant changes in length at baseline with an increasing number of cycles (p<0.05) and a significant interaction of cycle-material (p<0.001). The ΔΕ* parameter was significantly higher with a higher number of cycles (p<0.001), but it did not vary between materials (p>0.05). TP decreased similarly in both materials following microwave action but in a significantly higher level for Valplast (p<0.001).
CONCLUSIONS
The results indicated that long-term repeated microwaving affects linear dimensional, color and translucency changes of both materials. Differences between PMMA and polyamide material were noted only in dimension and translucency changes.
Topics: Analysis of Variance; Color; Colorimetry; Denture Bases; Disinfection; Interferometry; Materials Testing; Microwaves; Nylons; Polymethyl Methacrylate; Prosthesis Coloring; Reference Values; Reproducibility of Results; Surface Properties; Time Factors; Water
PubMed: 29898184
DOI: 10.1590/1678-7757-2017-0536 -
Materials (Basel, Switzerland) Jun 2018Currently, polymethylmethacrylate (PMMA) is the most popular denture base material. Most fractures of dentures that occur during function are due to its insufficient...
Currently, polymethylmethacrylate (PMMA) is the most popular denture base material. Most fractures of dentures that occur during function are due to its insufficient mechanical strength. The major drawbacks of PMMA are insufficient ductility, strength, and viscoelastic behavior. The purpose of this study was to evaluate a polymethylmethacrylate denture base material modified with TiO₂ nanoparticles in terms of nanomechanical, creep-recovery, and relaxation. Additionally, the effects of addition TiO₂ nanoparticles on the thermal and antimicrobial adhesion behaviors were investigated. Differential scanning calorimetry and thermogravimetric analysis indicated that the effect of small amounts of TiO₂ nanoparticles (1 wt. %, 2 wt. %, and 3 wt. %) on the degradation behavior of PMMA denture bases was insignificant. The nanomechanical test results of the PMMA and PMMA/TiO₂ nanocomposites indicated that the hardness and modulus in the nanoscale range improved due to TiO₂ addition. At a 1200-nm penetration depth, the modulus increased by 10%, 16%, and 29% and hardness increased by 18%, 24%, and 35% with the addition of 1 wt. %, 2 wt. %, and 3 wt. % TiO₂, respectively. Furthermore, the creep-recovery and relaxation behaviors of PMMA were significantly improved due to the addition of TiO₂. The creep strain decreased from 1.41% to 1.06%, 0.66%, and 0.49% with the addition of 1 wt. %, 2 wt. %, and 3 wt. % TiO₂, respectively. The relaxation test results showed that the initial stress under 1% strain improved to 19.9, 21.2, and 22 MPa with the addition of 1 wt. %, 2 wt. %, and 3 wt. % TiO₂, respectively. The improvement in the nanohardness, modulus, creep recovery, and relaxation behavior of PMMA due to the addition of TiO₂ nanoparticles indicated the role of the nanoparticles in increasing the PMMA matrix stiffness by reducing its mobility and free volume. TiO₂ nanoparticles also improved the antimicrobial behavior of PMMA by significantly reducing bacterial adherence with increasing TiO₂ ratio.
PubMed: 29954116
DOI: 10.3390/ma11071096 -
International Journal of Molecular... Sep 2022Polymers remain an integral part of denture fabrication materials, specifically polymethylmetacrylate (PMMA). PMMA has been extensively used, particularly in... (Review)
Review
Polymers remain an integral part of denture fabrication materials, specifically polymethylmetacrylate (PMMA). PMMA has been extensively used, particularly in construction as a denture base material. Nonetheless, various challenges, including microbial threats in the form of candidiasis occurrence, still remain a biological challenge to denture wearers. The present article comprehensively reviews the biomodifications introduced to denture components, in particular denture base material, to improve the overall biological properties, together with physical, mechanical, structural integrity, and optical properties. In addition, fundamental information specifically to PMMA as a conventional denture base material and the causative aetiological microbial agents for biological threat to dentures are explored.
Topics: Denture Bases; Dentures; Materials Testing; Polymers; Polymethyl Methacrylate; Surface Properties
PubMed: 36142344
DOI: 10.3390/ijms231810426 -
International Journal of Biomaterials 2021This study aimed to evaluate denture cleanser effects on color stability, surface roughness, and hardness of PMMA denture base resin reinforced with nano-ZrO.
OBJECTIVES
This study aimed to evaluate denture cleanser effects on color stability, surface roughness, and hardness of PMMA denture base resin reinforced with nano-ZrO.
MATERIALS AND METHODS
A total of 420 specimens were fabricated of unreinforced and nano-ZrO reinforced acrylic resin at 2.5% and 5%, resulting in 3 main groups. These groups were further subdivided ( = 10) according to immersion solution (distilled water, Corega, sodium hypochlorite, and Renew) and immersion duration. Surface roughness, hardness, and color were measured at baseline (2 days- ) in distilled water and then after 180 and 365 days of immersion ( & ) in water or denture cleansing solutions. Data was collected and analyzed using two-way ANOVA followed by Bonferroni post hoc test ( = 0.05).
RESULTS
Surface roughness increased significantly after denture cleanser immersion of unmodified and nano-ZrO-modified PMMA materials while hardness decreased ( < 0.001). The denture cleansers significantly affected the color of both PMMA denture bases ( < 0.001). The immersion time in denture cleansers significantly affected all tested properties ( < 0.001). Within denture cleansers, NaOCl showed the highest adverse effects ( < 0.05) while Renew showed the least adverse effects.
CONCLUSION
Denture cleansers can significantly result in color change and alter the surface roughness and hardness of denture base resin even with ZrO nanoparticles addition. Therefore, they should be carefully used.
PubMed: 33927766
DOI: 10.1155/2021/6668577 -
Dentistry Journal Jun 2018Currently, there is minimal clinical data regarding biofilm composition on the surface of denture bases and the clinical tissue compatibility. Therefore, the aim of this...
Currently, there is minimal clinical data regarding biofilm composition on the surface of denture bases and the clinical tissue compatibility. Therefore, the aim of this experimental study was to compare the bacterial colonization and the tissue compatibility of a hypoallergenic polyamide with a frequently used PMMA resin tested intraorally in a randomized split-mouth design. Test specimens made of polyamide ( = 10) and PMMA ( = 10) were attached over a molar band appliance in oral cavity of 10 subjects. A cytological smear test was done from palatal mucosa at baseline and after four weeks. The monolayers were inspected for micronuclei. After four weeks in situ, the appliance was removed. The test specimens were immediately cultivated on non-selective and selective nutrient media. All growing colonies were identified using VITEK-MS. The anonymized results were analyzed descriptively. A total of 110 different bacterial species could be isolated, including putative pathogens. An average of 17.8 different bacterial species grew on the PMMA specimens, and 17.3 on the polyamide specimens. The highest number of different bacterial species was = 24, found on a PMMA specimen. On the two specimens, a similar bacterial distribution was observed. Micronuclei, as a marker for genotoxic potential of dental materials, were not detected. This study indicates that the composition of bacterial biofilm developed on these resins after four weeks is not influenced by the type of resin itself. The two materials showed no cytological differences. This investigation suggests that polyamide and PMMA are suitable for clinical use as denture base material.
PubMed: 29914101
DOI: 10.3390/dj6020020 -
Clinical and Experimental Dental... Feb 2022This study aimed to evaluate the effect of different concentrations of titanium dioxide (TiO ) and copper oxide (CuO) nanoparticles on the water sorption and solubility...
OBJECTIVES
This study aimed to evaluate the effect of different concentrations of titanium dioxide (TiO ) and copper oxide (CuO) nanoparticles on the water sorption and solubility of heat-cured polymethyl methacrylate (PMMA).
MATERIALS AND METHODS
Fifty disc-shaped specimens (10 × 2 mm) of heat-cured PMMA were prepared and divided into five groups (n = 10) to be modified with 2.5 wt.% or 7.5 wt.% of either TiO or CuO nanoparticles. One group was left unmodified, serving as the control group. Water sorption and solubility were measured by weighing the specimens before and after immersion in distilled water and desiccation. The data were analyzed by using one-way ANOVA and Tukey's post hoc test (α = .05).
RESULTS
The 2.5 wt.% CuO nanoparticles significantly decreased the water sorption (p = .016), but did not change the water solubility (p = .222) compared with the control group. The 7.5 wt.% CuO and both concentration of TiO nanoparticles did not change the water sorption, but significantly increased the solubility of heat-cured PMMA (p ≤ .05).
CONCLUSION
Adding 2.5 wt.% CuO nanoparticles to heat-cured PMMA decreases the water sorption; although, it has no significant effect on the solubility. Likewise, 2.5 and 7.5 wt.% TiO and 7.5 wt.% CuO do not affect the water sorption, but increase the water solubility of heat-cured PMMA.
CLINICAL SIGNIFICANCE
Reinforcing the heat-cured PMMA denture base resin materials with the right concentration and type of nanoparticles can decrease the water sorption of resin base materials, and consequently can influence the durability of dentures.
Topics: Copper; Denture Bases; Hot Temperature; Materials Testing; Nanoparticles; Polymethyl Methacrylate; Solubility; Titanium; Water
PubMed: 35015382
DOI: 10.1002/cre2.527 -
BMC Oral Health May 2022Studies on the material properties and dimensional accuracy of three-dimensionally (3D) printed denture base containing microcapsules with antifungal phytochemicals are...
Effect of phytochemical-filled microcapsules with antifungal activity on material properties and dimensional accuracy of denture base resin for three-dimensional printing.
BACKGROUND
Studies on the material properties and dimensional accuracy of three-dimensionally (3D) printed denture base containing microcapsules with antifungal phytochemicals are lacking.
METHODS
Two types of phytochemicals (phytoncide A and B) with antifungal activity were microencapsulated. The 3D-printed denture base specimens with minimum and maximum effective concentrations of microcapsules (6 and 8 wt% for phytoncide A; 15 and 25 wt% for phytoncide B) were prepared. The morphological changes of C. albicans on 3D-printed denture base with microcapsules was microscopically observed. The degree of conversion of 3D-printed denture base with microcapsules investigated. The microhardness and flexural strength values were also measured to evaluate the mechanical properties of 3D-printed denture bases. The dimensional accuracy (trueness) of the specimens with microcapsules was measured as root-mean-square values (RMS) for the whole, upper, and side surfaces of the specimens as well as their total height. For the degree of conversion, microhardness, and flexural strength values, the Kruskal-Wallis analysis and a post-hoc comparison using Mann-Whitney U test was performed. For the analysis of trueness (RMS), the one-way analysis of variance and a post-hoc comparison using Tukey's method was conducted (α = 0.05).
RESULTS
At both maximum and minimum effective concentrations of microcapsules, cell surface disruption or membrane breakdown of fungal cells were observed in the specimens. The groups with microcapsules (both phytoncide A- and B-filled) showed significantly lower microhardness and elastic modulus values than the control group (all, P = 0.001). For the trueness, all the RMS values of the whole, upper, and side surfaces of the specimens with microcapsules were less than 100 µm, although significantly higher than those without (all, P = 0.001). The mean flexural strength values of the groups with phytoncide A-filled microcapsule were higher than 65 MPa, not statistically different from that of the control group (all, P > 0.05). However, the groups with phytoncide B-filled microcapsules showed significantly lower values than the control (all, P = 0.001).
CONCLUSIONS
Within the limitations of this in-vitro study, the 3D-printed denture base containing 6 wt% of phytoncide A-filled microcapsules was clinically acceptable in terms of antifungal activity, dimensional accuracy, and flexural strength.
Topics: Antifungal Agents; Candida albicans; Capsules; Denture Bases; Humans; Materials Testing; Monoterpenes; Phytochemicals; Printing, Three-Dimensional; Surface Properties
PubMed: 35562746
DOI: 10.1186/s12903-022-02216-z