RESUMEN
Orbital defects due to congenital causes, cancer, and trauma can compromise appearance and function, creating a deep psychological impact on an individual's life. The prosthetic rehabilitation of such patients is challenging. The objective of prosthetic treatment of an ocular defect is to provide a well-fitting ocular prosthesis that closely resembles the original eye, restoring the patient's self-confidence and social acceptance. Ocular prostheses can be customized or prefabricated. The challenge encountered with prefabricated eye prostheses is a poor fit. Customized prostheses exhibit better fit, aesthetic outcome, and comfort to the patient in the long term. The article describes a technique to fabricate an ocular prosthesis with a stock iris and customized sclera that is both functional and aesthetically pleasing.
RESUMEN
Aim The aim of this study is to evaluate and compare the microhardness and polymerization shrinkage of polymethyl methacrylate reinforced with residual zirconia. Materials and methods A total of 360 resin samples were fabricated, with dimensions of 12 mm × 12 mm × 3 mm and 12 mm × 8 mm × 6 mm. Zirconia dust (40% by weight) was added to 180 of these samples. The study included four groups: Group A (autopolymerizing acrylic resin), Group H (heat-polymerizing acrylic resin), Group ZA (autopolymerizing acrylic resin with zirconia dust), and Group ZH (heat-polymerizing acrylic resin with zirconia dust). Each group consisted of 90 samples, with 45 samples used for evaluating microhardness and 45 samples for assessing polymerization shrinkage. Results Group ZH exhibited the highest microhardness at 6.06 ± 0.31 GPa. It also recorded the lowest shrinkage values, measuring 52.11 ± 3.21 mm³. Tukey's honestly significant difference test revealed that microhardness was significantly higher in Group ZA (4.53 ± 0.29 GPa) compared to Group A (3.51 ± 0.25 GPa). However, Group H (5.42 ± 0.26 GPa) demonstrated greater hardness than Group ZA. Regarding shrinkage, the addition of zirconia dust resulted in reduced values, with Group ZA (73.93 ± 3.55 mm³) showing less shrinkage compared to Group A (91.9 ± 6.38 mm³). Similarly, Group ZH (52.11 ± 3.21 mm³) had lower shrinkage than Group H (66.71 ± 5.97 mm³). Group A exhibited the highest shrinkage among all the groups. Conclusion Within the limitations of this study, it can be concluded that there is an increase in hardness and a decrease in shrinkage values of the resin with the addition of zirconia dust in heat and autopolymerizing acrylic resin used for the fabrication of provisional restorations. Zirconia-incorporated heat-activated resin showed superior microhardness and decreased shrinkage values. Although the addition of residual zirconia to autopolymerized samples demonstrated better hardness, it was observed that pure heat-polymerized samples showed greater hardness. Reusing computer-aided design and computer-aided manufacturing powder waste can cut down on economic losses and aid in environmental sustainability.
RESUMEN
Objective This study aims to evaluate the effects of immersion in alcoholic beverages on the surface roughness and color stability of two types of milled zirconia. Materials and methods The sample size included 60 cuboid-shaped samples of two types of zirconia (Z1 and Z2), 30 in each group. Zirconia was milled and sintered at 1,500°C for eight hours. The samples were immersed in artificial saliva (control), red wine, and whiskey three times a day over a 30-day period. After each post-immersion cycle, samples were cleaned ultrasonically. Surface roughness and color parameters were measured using an atomic force microscope (AFM) and spectrophotometer before and after immersion. The collected data was organized into tables, and statistical analysis was conducted using the Statistical Package for the Social Sciences (SPSS) version 27 software (IBM SPSS Statistics, Armonk, NY). For surface roughness, a paired t-test was conducted, while for color change, one-way analysis of variance (ANOVA) and Tukey's honestly significant difference (HSD) tests were done. Results The mean values of pre- and post-immersion values reveal that whiskey causes the highest difference in surface roughness for Z1 (137.09 nm) and Z2 (86.15 nm) groups, while red wine causes maximum discoloration in both Z1 (2.41) and Z2 (1.94) groups. The paired t-test revealed significant surface roughness changes in Z1 with artificial saliva and red wine, while whiskey (p<0.05), although showing changes, lacked statistical significance (p>0.05). The whiskey group demonstrated a moderate linear association (0.599) between pre- and post-immersion values. For Z2, artificial saliva, red wine, and whiskey (p<0.05) induced statistically significant surface roughness alterations. ANOVA tests indicated significant color changes post-immersion in all three subgroups of Z1 and Z2 (p<0.05 for both). Tukey's HSD test showed significant differences between artificial saliva and red wine (p<0.05), as well as artificial saliva and whiskey (p<0.05) in Z1 and Z2. However, no significant difference was found between red wine and whiskey in both Z1 and Z2 groups (p>0.05). Conclusion Whiskey, red wine, and artificial saliva increased zirconia's surface roughness. Alcoholic solutions altered zirconia's colorimetric parameters, with no significant differences among them.
RESUMEN
Introduction The denture bases fabricated from polymethylmethacrylate (PMMA) have some disadvantages, such as surface prone to microbial growth and biofilm accumulation, which contributes to the onset and dissemination of infections among denture wearers. Therefore, the purpose of this in vitro study was to evaluate the flexural strength, hardness, and antimicrobial effect of denture base resin incorporated with 0.05% and 0.1% silver nanoparticles (AgNPs) of Aloe barbadensis miller (aloe vera), Morinda citrifolia (noni), and Boesenbergia rotunda (finger root). Materials and methods A total of 84 PMMA samples were used and were divided into three groups. Flexural strength tests were performed on Group 1 PMMA blocks. Group 2 involved hardness testing of PMMA blocks, whereas Group 3 involved antimicrobial activity. Each group was subsequently split into seven subgroups with differing concentrations of AgNPs: Sub Group 1: control (no AgNPs), Sub Group 2: 0.05% aloe vera AgNPs, Sub Group 3: 0.1% aloe vera AgNPs, Sub Group 4: 0.05% noni AgNPs, Sub Group 5: 0.1% of noni AgNPs, Sub Group 6: 0.05% finger root AgNPs, and Sub Group 7: 0.1% finger root AgNPs. The flexural strength was evaluated using a universal testing machine (Instron 8801). Surface hardness was measured using a Vickers tester (Tukon 1102). For the antimicrobial activity analysis, the samples were incubated in a suitable culture broth containing Candida albicans for 24 hours. Microbial colony count (colony-forming unit (CFU)/mL) was estimated to evaluate the microbial adhesion to the surface of the denture base materials. Statistical analysis The flexural strength, hardness, and CFU between the groups were analyzed using one-way analysis of variance (ANOVA) followed by multiple comparisons with Tukey's honest significant difference (HSD) test (α=0.05). The level of statistical significance was determined at p<0.05. Results It was observed that the mean flexural strength was maximum in PMMA incorporated with 0.05% of aloe vera AgNPs and least in PMMA incorporated with 0.1% noni AgNPs. It was seen that a steady loss in flexural strength is observed from 0.05% to 0.1%. The mean hardness was maximum in PMMA incorporated with 0.1% of noni AgNPs and least in PMMA incorporated with 0.05% aloe vera AgNPs. It was also found that the hardness was directly proportional to the number of nanoparticles. With an increase in the weight percentage of nanoparticles, a steady increase in hardness was seen in all the test groups. In our study, the results showed that finger root 0.1% showed the least CFU with a significant reduction of C. albicans adherence; therefore, it indicates higher anti-fungal activity. Aloe vera 0.05% showed the lowest inhibition of C. albicans, suggesting the least anti-fungal activity. Conclusion Within the limitations of this study, It can thus be concluded that the addition of AgNPs incorporated with plant extracts of Aloe barbadensis miller (aloe vera), Morinda citrifolia (noni), and Boesenbergia rotunda (finger root) can alter the flexural strength, hardness, and microbial adhesion of PMMA. In our study, it can be concluded that flexural strength increases with the addition of AgNPs of 0.5% concentration after which a steady loss is seen. However, the hardness and antimicrobial activity increased with an increase in the concentration of AgNPs in all three plant extracts.
RESUMEN
OBJECTIVE: The purpose of this in vitro study is to compare and evaluate the surface roughness and microbial adhesion of Staphylococcus aureus and Candida albicans after the finishing and polishing of three different denture base materials. MATERIALS AND METHODS: A total of 84 samples of three different denture materials were used. The samples were divided into three groups: Group I (conventional poly methyl methacrylate), Group II (injection-molded polymethyl methacrylate), and Group III (injection-molded polyamide). Fourteen samples from each group were tested for surface roughness using an optical profilometer. Seven samples from each group were incubated in a suitable culture broth containing Candida albicans and Staphylococcus aureus separately for 48 hours. Microbial colony forming unit (cfu/ml2) was estimated in order to evaluate the microbial adhesion to the surface of the denture base materials. Confocal laser scanning microscopy was done to visualize the microorganisms. RESULTS: The mean surface roughness of Group I was 0.1176± 0.04 µm, Group II was 0.0669±0.02 µm, Group III was 0.1971±0.02 µm. One-way ANOVA revealed statistically significant differences in the mean surface roughness values among the three groups (p < 0.05). Tukey HSD (honestly significant difference) test confirmed the specific differences within the groups. The results of colony forming unit showed maximum adherence in Group III samples among both the species followed by Group I samples and least in Group II samples. Confocal laser scanning microscopy revealed significant differences in microbial adhesion among both Staphylococcus aureus and Candida albicans in the three groups (p <0.05). One-way multivariate ANOVA was performed to analyze the data obtained from confocal laser scanning microscopy. Microbial adhesion was least observed in Group II samples followed by Group I samples and the highest microbial adhesion was observed in Group III samples. CONCLUSION: Microbial adhesion was proved to have a direct correlation with the surface roughness of denture base materials. An increase in surface roughness (Ra) increases microbial adhesion.