Rodrigues, Danieli C.
Permanent URI for this collectionhttps://hdl.handle.net/10735.1/4062
Danieli Rodrigues is an Assistant Professor of Biomedical Engineering. Serving as a Research Engineer within the medical device industry, she developed test methods for performance verification and validation of new designs of hip and knee prostheses and related surgical instrumentation. Her graduate research focused on orthopedic biomaterials, primarily working on the characterization of corrosion and failure mechanisms of hip implants and development of acrylic two-solution bone cements for treatment of spinal compression fractures.
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Browsing Rodrigues, Danieli C. by Author "0000-0002-0389-0833 (Rodrigues, DC)"
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Item Can Oral Bacteria and Mechanical Fatigue Degrade Zirconia Dental Implants in Vitro?(American Chemical Society, 2019-05-15) Siddiqui, Danyal A.; Sridhar, Sathyanarayanan; Wang, Frederick; Jacob, Joel J.; Rodrigues, Danieli C.; 0000-0002-2398-5979 (Siddiqui, DA); 0000-0002-0389-0833 (Rodrigues, DC); Siddiqui, Danyal A.; Sridhar, Sathyanarayanan; Wang, Frederick; Jacob, Joel J.; Rodrigues, Danieli C.Zirconia (ZrO₂) is an emerging alternative to titanium for dental implant systems due to its material properties including high mechanical strength and chemical stability. However, oral environmental factors such as bacterial adhesion and mechanical fatigue may trigger low-temperature degradation of ZrO₂, leading to reduced mechanical strength and potential implant fracture. Although failure modes of ZrO₂ in orthopedic applications have been studied, they have yet to be thoroughly investigated in the context of dental implant systems. Thus, the goal of the present study was to assess the surface of ZrO₂ dental implants for signs of degradation after exposure to oral bacteria and oral bacteria in combination with mechanical fatigue. ZrO₂ dental implants were subjected to 30-day immersion in (i) early or (ii) late colonizing oral bacteria or (iii) were mechanically loaded for 2 × 106 cycles with oral bacteria in circulation. Optical microscopy, Raman microscopy, and X-ray photoelectron spectroscopy (XPS) were used to evaluate the surface morphology, phase composition, and chemical composition, respectively. Post-immersion, all implants exhibited minimal changes in surface features, and all loaded implants survived cyclic fatigue tests. All implants had <1% monoclinic phase at the collar, junction, and screw regions, excluding the screw threads, for which monoclinic phase was significantly higher but <10%. XPS revealed an increase in carbon- and nitrogen-based organic debris on the implants exposed to early colonizers as compared to those immersed in late colonizers or synergistically with mechanical loading. Within the limitations of the present study, ZrO₂ is a suitable alternative material for dental implant systems based on its ability to resist both physical and chemical degradation imposed by oral bacteria and applied cyclic loads. © 2019 American Chemical Society.Item Effects of Titanium Oxide Surface Properties on Bone-Forming and Soft Tissue-Forming Cells(Wiley) Wheelis, Sutton E.; Montaño-Figueroa, Ana Gabriela; Quevedo-Lopez, Manuel A.; Rodrigues, Danieli C.; 0000-0003-4068-9896 (Wheelis, SE); 0000-0002-0389-0833 (Rodrigues, DC); Wheelis, Sutton E.; Montaño-Figueroa, Ana Gabriela; Quevedo-Lopez, Manuel A.; Rodrigues, Danieli C.Background: Previous studies have concluded that certain titanium oxide (TiO₂) surface properties promote bone-forming cell attachment. However, no comprehensive studies have investigated the effects of TiO₂ surface and film morphology on hard and soft tissues. Purpose: The aim of this study is to understand the effects of TiO₂ morphology on the proliferation and differentiation of murine preosteoblasts (MC3T3-E1) and proliferation of human gingival fibroblasts (HGF-1) using in vitro experiments. Materials and Methods: Samples were fabricated with several TiO₂ thickness and crystalline structure to mimic various dental implant surfaces. in vitro analysis was performed for 1, 3, and 7 days on these samples to assess the viability of MC3T3-E1 and HGF-1 cells in contact with the modified oxide surfaces. Results: Results showed that HGF-1 cells exhibited no significant difference in viability on modified oxide surfaces versus a titanium control across experiments. MC3T3-E1 cells exhibited a significantly higher viability for the modified oxide surface in 1 day experiments, but not in 3 or 7 day experiments. Alkaline phosphatase expression in MC3T3-E1 was not significantly different on modified oxide surfaces versus the control across all experiments. A slight positive trend in viability was observed for cells in contact with rougher modified oxide surfaces versus a titanium control in both cell types. Conclusions: These observations suggest that crystallinity and thickness do not affect the long-term viability of hard or soft tissue cells when compared to a cpTi surface. Therefore, treatments like anodization on implant components may not directly affect the attachment of hard or soft tissue cells in vivo. © 2018 Wiley Periodicals, Inc.Item Evaluation of Oral Microbial Corrosion on the Surface Degradation of Dental Implant Materials(Wiley, 2018-08-13) Siddiqui, Danyal A.; Guida, Lidia; Sridhar, Sathyanarayanan; Valderrama, Pilar; Wilson, Thomas G., Jr.; Rodrigues, Danieli C.; 0000-0002-0389-0833 (Rodrigues, DC); Rodrigues, Danieli C.; Siddiqui, Danyal A.; Guida, Lidia; Sridhar, SathyanarayananBackground: Titanium (Ti) dominates as the material of choice for dental implant systems. Recently, titanium-zirconium alloy (TiZr) and zirconia (ZrO₂) have emerged as alternative materials due to higher mechanical strength and lower corrosion susceptibility. Oral pathogenic bacteria can colonize Ti surfaces, leading to surface degradation, which has yet to be investigated on TiZr and ZrO₂. The aim of this study was to compare in vitro oral bacterial adhesion and subsequent surface degradation on commercial Ti, TiZr, and ZrO₂ implants. Methods: Ti, TiZr, and ZrO₂ implants with sandblasted, acid-etched (SLA) surfaces in addition to modified SLA-treated (modSLA) Ti implants (n = 3) were immersed for 30 consecutive days in Streptococcus polyculture. Post-immersion, adherent bacterial count was quantified. Optical microscopy was used to assess qualitative degradation and score Ti-based implants based on degree of surface damage while electrochemical testing quantified corrosion behavior. Analysis of variance followed by post-hoc Tukey test was used to statistically compare quantitative results (alpha = 0.05). Results: Ti-SLA, Ti-modSLA, and TiZr-SLA implants exhibited localized features characteristic of corrosion attack while ZrO₂-SLA implants experienced minimal changes in surface morphology as compared to non-immersed control. Corrosion features were more numerous on Ti-modSLA implants but smaller in size as compared with those on Ti-SLA and TiZr-SLA implants. No significant differences in corrosion resistance (polarization resistance and corrosion rate) were observed between Ti-SLA, Ti-modSLA, and TiZr-SLA implants. Conclusion: TiZr and ZrO₂ dental implant surfaces were not more susceptible to colonization and surface degradation by oral Streptococcus species than commercially pure Ti implants.Item In Vitro Evaluation of Cell Compatibility of Dental Cements Used with Titanium Implant Components(Wiley, 2019-02) Marvin, Jason C.; Gallegos, Silvia I.; Parsaei, Shaida; Rodrigues, Danieli C.; 0000-0002-0389-0833 (Rodrigues, DC); Marvin, Jason C.; Gallegos, Silvia I.; Parsaei, Shaida; Rodrigues, Danieli C.Purpose To evaluate the biocompatibility of five dental cement compositions after directly exposing human gingival fibroblast (HGF) and MC3T3-E1 preosteoblast cells to cement alone and cement applied on commercially pure titanium (cpTi) specimens. Materials and Methods Nanostructurally integrated bioceramic (NIB), resin (R), resin-modified glass ionomer (RMGIC), zinc oxide eugenol (ZOE), and zinc phosphate (ZP) compositions were prepared according to the respective manufacturer's instructions. Samples were prepared in cylindrical Teflon molds or applied over the entire surface of polished cpTi discs. All samples were cured for 0.5, 1, 12, or 24 hours post-mixing. Direct contact testing was conducted according to ISO 10993 by seeding 6-well plates at 350,000 cells/well. Plates were incubated at 37 degrees C in a humidified atmosphere with 5% CO2 for 24 hours before individually plating samples and cpTi control discs. Plates were then incubated for an additional 24 hours. Microtetrazolium (MTT) cell viability assays were used to measure sample cytotoxicity. Results For samples that cured for 24 hours prior to direct contact exposure, only NIB and ZP cements when cemented on cpTi demonstrated cell viability percentages above the minimum biocompatibility requirement (>= 70%) for both the investigative cell lines. R, RMGIC, and ZOE cements exhibited moderate to severe cytotoxic effects on both cell lines in direct contact and when cemented on cpTi specimens. For HGF cells, ZOE cemented-cpTi specimens exhibited significantly decreased cytotoxicity, whereas RMGIC cemented-cpTi specimens exhibited significantly increased cytotoxicity. Conclusions Despite previous studies that showed enhanced cpTi corrosion activity for fluoride-containing compositions (NIB and ZP), there was no significant difference in cytotoxicity between cement alone and cemented-cpTi. In general, the MC3T3-E1 preosteoblast cells were more sensitive than HGF cells to cement composition. Ultimately, cement composition played a significant role in maintaining host cell compatibility. Results of this work help illustrate the impact of different cement formulations on host cell health and emphasize the need for understanding material properties when selecting certain formulations of dental cements, which can ultimately influence the survival of dental implant systems.