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Browsing by Author "Sochacki, Sabrina Feitosa"
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Item Effect of Toothbrushing on a Monolithic Dental Zirconia Submitted to an Accelerated Hydrothermal Aging(2022) Almajed, Norah; Sochacki, Sabrina Feitosa; Cook, Norman Blaine; Capin, Oriana ReisItem EGCG-Encapsulated Halloysite Nanotube Modified-Adhesive for Longer-Lasting Dentin-Resin Interfaces(2022-07) Alhijji, Saleh Mohammed; Windsor, L. Jack; Platt, Jeffrey A.; Bottino, Marco C.; Manicke, Nicholas; Sochacki, Sabrina FeitosaThe degradation of the resin-dentin interface after restoration placement is multifactorial and can be attributed in part to matrix metalloproteinases (MMPs) enzymes associated with recurrent and secondary caries progression. This dissertation aimed to synthesize and characterize the effects of Epigallocatechin-3-gallate (EGCG) from green tea extract as an MMP-inhibitor loaded into a dental adhesive using slow therapeutic compound release nanotubes as a reservoir to allow sustained and slow release. Loading efficiency and drug release were evaluated using a UV-vis spectrometer. The effects on the degree of conversion (DC), polymerization conversion (PC), and Vickers Micro-Hardness (VHN) tests were performed. MMP mediated β-casein (bCN) cleavage rate was used to determine the potency of the eluates contained EGCG to inhibit MMP-9 activity. The results indicated that HNTs could hold about 21.35% (±4.2%) of the EGCG used in the encapsulation process. The addition of 7.5% HNT or 7.5% EGCG-encapsulated HNT adhesive groups did not alter the curing efficiency indicated by the degree of conversion, polymerization conversion, and surface hardness results compared to the control group (p> 0.05). A statistically significant influence of adding HNTs was found to slow down the EGCG release measured up to 8 weeks (p< 0.05). There was a significant decrease in the degradation of β-casein mediated by pre-activated MMP-9 exposed to eluates from EGCG adhesives compared to non-EGCG adhesive groups (p< 0.05). The results suggested that using HNTs for EGCG encapsulating can remedy the negative impact of EGCG on the adhesive’s polymerization and still have the MMP-inhibitory effect and longer release period. Dentin adhesive containing EGCG-encapsulated HNT may contribute to the long-term preservation of restorations through slow and controlled release to maintain the dentin-resin interface's integrity by inhibiting MMP activity.Item Fracture Resistance Behaviors of Titanium-Zirconium and Zirconia Implants(Wiley, 2021) Hanes, Brenda; Sochacki, Sabrina Feitosa; Phasuk, Kamolphob; Levon, John A.; Morton, Dean; Lin, Wei-Shao; Prosthodontics, School of DentistryPurpose To evaluate the fracture resistance behaviors of titanium-zirconium, one-piece zirconia, and two-piece zirconia implants restored by zirconia crowns and different combinations of abutment materials (zirconia and titanium) and retention modes (cement-retained and screw-retained zirconia crowns). Material and Methods Three research groups (n=12) were divided according to combinations of abutment material, retention mode, and implant type. In the control group (TTC), titanium-zirconium implants (∅ 4.1 mm RN, 12 mm, Roxolid; Straumann USA) and prefabricated titanium abutments (RN synOcta Cementable Abutment, H 5.5 mm; Straumann USA) were used to support cement-retained zirconia crowns. In the second group (ZZC), one-piece zirconia implants (PURE Ceramic Implant Monotype, ∅ 4.1 mm RD, 12 mm, AH 5.5 mm; Straumann USA) were used to support cement-retained zirconia crowns. In the third group (ZTS), two-piece zirconia implants (PURE Ceramic Implant, ∅ 4.1 mm RD, 12 mm) and prefabricated titanium abutments (CI RD PUREbase Abutment, H 5.5 mm) were used to support screw-retained zirconia crowns. All zirconia crowns were manufactured in the same anatomic contour with a 5-axis dental mill and blended 3 and 5 mol% yttria-stabilized zirconia (LayZir A2). Implants were inserted into specimen holders made of epoxy resin-glass fiber composite. All specimens were then subject to artificial aging in an incubator at 37 C° for 90 days. Fracture resistance of specimen assemblies was tested under static compression load using the universal testing machine following ISO14801 specification. The peak fracture loads were recorded. All specimens were examined at the end of the test microscopically at 5 × and 10 × magnification to detect any catastrophic failures. Comparisons between groups for differences in peak fracture load were made using Wilcoxon Rank Sum tests and Weibull and Kaplan-Meier survival analyses (α = .05). Results The TTC group (942 ±241 N) showed significantly higher peak fracture loads than the ZZC (645 ±165 N) and ZTS (650 ±124 N) groups (p < .001), while there was no significant difference between ZZC and ZTS groups (p = 0.940). The survival probability based on the Weibull and Kaplan-Meier models demonstrated different failure molds between titanium- zirconium and zirconia implants, in which the TTC group remained in the plastic strain zone for a longer period before fracture when compared to ZZC and ZTS groups. Catastrophic failures, with implant fractures at the embedding level or slightly below, were only observed in the ZZC and ZTS groups. Conclusions Cement-retained zirconia crowns supported by titanium-zirconium implants and prefabricated titanium abutments showed superior peak fracture loads and better survival probability behavior. One-piece zirconia implants with cement-retained zirconia crowns and two-piece zirconia implants with screw-retained zirconia crowns on prefabricated titanium abutment showed similar peak fracture loads and survival probability behavior. Titanium-zirconium and zirconia implants could withstand average intraoral mastication loads in the incisor region. This study was conducted under static load, room temperature (21.7 °C), and dry condition, and full impacts of intraoral hydrothermal aging and dynamic loading conditions on the zirconia implants should be considered and studied further.Item A Modified Adhesive System for Use in Treatment of Dentin Hypersensitivity(2020-08) AlShehri, Aram Mushabbab; Sochacki, Sabrina Feitosa; Hara, Anderson; Platt, Jeffrey A.; Windsor, L. Jack