Thesis
Dentin bond strength of a dental adhesive system containing proanthocyanidin-loaded mesoporous silica nanoparticles
University of Iowa
Master of Science (MS), University of Iowa
Spring 2021
DOI: 10.17077/etd.005947
Abstract
ABSTRACT
Objectives: The incorporation of functionalized mesoporous silica nanoparticles (MSNs) into dental adhesives is a novel strategy for the sustained delivery of therapeutics to the resin-dentin interface. This study assessed the immediate bonding performance of an experimental primer containing MSN loaded with proanthocyanidins (PACs) from grape seed extract (GSE) (Vitis vinifera).
Methods: MSNs were fabricated, functionalized with an aminosilane (3-aminopropyltriethoxysilane, APTES), and loaded with PACs. An experimental primer (Exp) was formulated and composed of Bis-GMA, HEMA, CQ, EDMAB, and ethanol. Extracted intact human molars were used for adhesion studies using the different experimental primer formulations: Exp, Exp + MSN (Exp containing unloaded MSN), Exp + MSN-APTES (Exp containing unloaded MSN functionalized with APTES), Exp + MSN-APTES-PACs (Exp containing MSN loaded with PACs after functionalization), and Exp + MSN-PACs-APTES (Exp containing MSN loaded with PACs before functionalization). After acid etching with 35% phosphoric acid for 15 s, the different primers were applied on moist dentin. Then, Adper Scotchbond Multipurpose (SBMP) (3M Oral Care; St. Paul, MN, USA) dental adhesive was applied according to the manufacturer’s instructions, and teeth were incrementally restored with a dental composite (Filtek Supreme Ultra, 3M Oral Care). Immediate resin-dentin bond strength was evaluated using shear (SBS) (n = 10 teeth/group) and microtensile (µTBS) tests (n = 18 specimens/group) and results were expressed in megapascal (MPa). After the test, the resin-dentin samples prepared for the µTBS were classified according to the failure mode in adhesive, cohesive, or mixed. For SBS, one-way ANOVA and Tukey post-hoc tests were used to compare differences among groups. For the µTBS results, statistical analysis was conducted using linear mixed–effects model (LMER) to account for within-sample correlations followed by Tukey-adjusted pairwise post-hoc test (α=0.05).
Results: The addition of MSN-APTES to the Exp resulted in similar SBS to the commercial primer from SBMP (32.01±9.03 MPa and 42.02±11.82 MPa, respectively) (p=0.99). No statistically significant difference was observed among Exp + MSN-APTES and Exp (30.87±7.64 MPa), Exp+MSN (21.10±7.10 MPa), and Exp + MSN-PACs-APTES (20.88±8.71 MPa) (p≥0.05). The lowest SBS was obtained with Exp + MSN-APTES-PACs (17.52±3.24 MPa), but no significant difference was observed when compared to Exp + MSN-PACs-APTES (p=0.95). Regarding the µTBS results, the Exp + MSN-PACs-APTES presented statistically significant higher bond strength (33.33±9.63 MPa) than the other groups (all pairwise p<0.023). No statistically significant difference was observed among the other three primer formulations (Exp = 21.54±11.09 MPa; Exp + MSN-APTES = 20.40±8.74 MPa; and Exp + MSN-APTES-PACs = 20.25±10.01 MPa) (p≥0.97). Summary statistics showed that more than 90% of the failure modes in each group were in the adhesive category and only 5 specimens in total presented mixed failure.
Conclusion: APTES-functionalized MSN can be successfully added to an experimental primer for drug-delivery purposes without compromising the bond strength to dentin or failure mode. Additionally, loading MSN with PACs prior to surface functionalization with an aminosilane resulted in a better immediate bond strength than loading afterward.
Details
- Title: Subtitle
- Dentin bond strength of a dental adhesive system containing proanthocyanidin-loaded mesoporous silica nanoparticles
- Creators
- Sundes Elfagih
- Contributors
- Cristina Vidal (Advisor)Steven Armstrong (Committee Member)Allan Guymon (Committee Member)Erica Teixeira (Committee Member)Jin Xian Xie (Committee Member)
- Resource Type
- Thesis
- Degree Awarded
- Master of Science (MS), University of Iowa
- Degree in
- Oral Science
- Date degree season
- Spring 2021
- DOI
- 10.17077/etd.005947
- Publisher
- University of Iowa
- Number of pages
- x, 54 pages
- Copyright
- Copyright 2021 Sundes Elfagih
- Language
- English
- Description illustrations
- illustrations (some color)
- Description bibliographic
- Includes bibliographical references (pages 48-54)
- Public Abstract (ETD)
Despite recent advances, a major problem with dental composites or tooth-colored fillings is the loss of seal to the tooth, which leads to discoloration and decay. The repair or replacement of these fillings are inconvenient, costly, time-consuming, and lead to unnecessary removal of sound tooth structure. To overcome the bonding vulnerability, studies found that a natural compound derived from grape seeds [proanthocyanidins (PACs) from grape seed extract] reinforces the bond to the tooth. However, the need for an additional step in the application protocol if PACs is applied before bonding, the limited PACs availability and the alteration of the adhesive properties when PACs is directly incorporated into the bonding material, have challenged its potential translation to the clinic. Nano-sized carriers, such as mesoporous silica nanoparticles (MSN), have shown promising results in medicine as vehicles to carry drugs to targeted sites. This study, aiming to promote long-lasting dental fillings, proposes the use of MSN for PACs delivery to the tooth-dental composite interface. PACs-loaded MSN were incorporated into a dental adhesive and the strength of the bond to the tooth was investigated. Our results showed that the bonding materials containing PACs-loaded MSN has either maintained or improved the strength of the bond to the tooth in comparison to an adhesive without these nanoparticles. Future studies will be focused on the long-term bonding performance of PACs-loaded nanoparticles aiming at increasing the stability of the dental fillings.
- Academic Unit
- Oral Pathology, Radiology and Medicine
- Record Identifier
- 9984097275702771
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