Mechanical Properties of Orthodontic Cements and Their Behavior in Acidic Environments

Abstract

The present research is focused on three different classes of orthodontic cements: resin composites (e.g., BracePaste); resin-modified glass ionomer RMGIC (e.g., Fuji Ortho) and resin cement (e.g., Transbond). Their mechanical properties such as compressive strength, diametral tensile strength and flexural strength were correlated with the samples’ microstructures, liquid absorption, and solubility in liquid. The results show that the best compressive (100 MPa) and flexural strength (75 Mpa) was obtained by BracePaste and the best diametral tensile strength was obtained by Transbond (230 MPa). The lowestvalues were obtained by Fuji Ortho RMGIC. The elastic modulus is relatively high around 14 GPa for BracePaste, and Fuji Ortho and Transbond have only 7 GPa. The samples were also subjected to artificial saliva and tested in different acidic environments such as Coca-Cola and Red Bull. Their absorption and solubility were investigated at different times ranging from 1 day to 21 days. Fuji Ortho presents the highest liquid absorption followed by Transbond, the artificial saliva has the best absorption and Red Bull has the lowest absorption. The best resistance to the liquids was obtained by BracePaste in all environments. Coca-Cola presents values four times greater than the ones observed for artificial saliva. Solubility tests show that BracePaste is more soluble in artificial saliva, and Fuji Ortho and Transbond are more soluble in Red Bull and Coca-Cola. Scanning electron microscopy (SEM) images evidenced a compact structure for BracePaste in all environments sustaining the lower liquid absorption values. Fuji Ortho and Transbond present a fissure network allowing the liquid to carry out in-depth penetration of materials. SEM observations are in good agreement with the atomic force microscopy (AFM) results. The surface roughness decreases with the acidity increasing for BracePaste meanwhile it increases with the acidity for Fuji Ortho and Transbond. In conclusion: BracePaste is recommended for long-term orthodontic treatment for patients who regularly consume acidic beverages, Fuji Ortho is recommended for short-term orthodontic treatment for patients who regularly consume acidic beverages and Transbond is recommended for orthodontic treatment over an average time period for patients who do not regularly consume acidic beverages.

Chemical and Structural Assessment of New Dental Composites with Graphene Exposed to Staining Agents

“…Wine affects the structure of resin composites and teeth due to its alcohol content, which causes increased surface roughness and erosion in composites [ 19 , 20 ]. Lower pH values of coloured media has been reported to increase staining, possible by favouring degradation of the polymer chain [ 43 , 44 ]. Some studies have reported that colour changes are influenced by increased surface roughness allowing stain penetration [ 39 ].…”

Shear bond strength of a RMGIC for orthodontic bracket bonding to enamel

“…This result was con rmed by the ndings of other studies where TXT obtained good results. 38,[40][41][42] In fact, composite resins had better mechanical properties and rigidity than RMGICs. 5,6,42 Authors explained these ndings by a possible correlation between exural modulus and SBS value: the higher the exural modulus is, the better the SBS.…”

“…38,[40][41][42] In fact, composite resins had better mechanical properties and rigidity than RMGICs. 5,6,42 Authors explained these ndings by a possible correlation between exural modulus and SBS value: the higher the exural modulus is, the better the SBS. [40][41][42] These differences in exural modulus between the two RMGICs analysed could partly explain the higher SBS obtained by FUJI than by RIVA.…”

Synthesis, Physicochemical Characterization and Applications of Advanced Nanomaterials

“…Iosif et al [ 17 ] reported on the mechanical properties of orthodontic cements and their behavior in acidic environments and investigated the mechanical properties and morphology of three categories of orthodontic cements: resin composites (BracePaste); resin-modified glass ionomer (Fuji Ortho) and resin cement (Transbond) exposed to acidic environments such as Coca Cola TM and Red Bull TM . Their mechanical properties, such as compressive strength, diametral tensile strength, and flexural strength, were correlated with the samples’ microstructures, liquid absorption, and solubility in liquid [ 17 ]. The findings suggest that Transbond resin cement presents the best compression strength and BracePaste features the best flexural strength.…”

“…The acidic components within these soft drinks (phosphoric acid in Coca-Cola TM and citric acid in Red Bull TM ) can erode the bonding layer and affect the bracket’s stability. Atomic force microscopy reveals the nanostructural alteration of the investigated orthodontic materials, such as roughness increasing and nano-filler particles acid erosion [ 17 ]. It was found that these parameters strongly influence the orthodontic material behavior (e.g., BracePaste roughness decreasing under acid exposure proves an excellent resistance to in-depth erosive penetration), a fact that must be considered when the orthodontic treatment is prescribed to the patient.…”