Evaluation of the microhardness of different resin‐based dental restorative materials treated with gastric acid: Scanning electron microscopy–energy dispersive X‐ray spectroscopy analysis

Abstract

The aim of this study is to evaluate the microhardness, relative surface roughness, and elemental changes of resin‐based dental restorative materials (RDRMs) after gastric acid treatment. Five different RDRMs (Group 1 [Filtek Z550], Group 2 [Beautifil II], Group 3 [Vertise Flow], Group 4 [Dyract XP], Group 5 [Fuji II LC]) were used. Samples were formed by using plexiglass molds of 10 mm diameter and 2 mm thickness. A total of 50 samples (n = 10) for microhardness tests and a total of 15 samples (n = 3) for scanning electron microscopy (SEM)–energy dispersive X‐ray spectroscopy (EDX) analysis were prepared. All samples of each group were treated to gastric acid, simultaneously. A Vickers microhardness tester was used to evaluate the microhardness of the upper surfaces of each sample. SEM–EDX system was used for microstructure and elemental composition detection. The SEM–EDX, microhardness and relative surface roughness analysis were made prior to treatment in gastric acid for 14 days and analysis were repeated on the 14th day. As the difference in the microhardness values of RDRMs was compared, the time‐dependent variation in all RDRMs was found to be statistically significant. It was observed that a drastic decrease in microhardness values was in Beautifil II, Filtek Z550, Vertise Flow, Fuji II LC, and Dyract XP, respectively. Average decrease rate of microhardness values compared to the initial state can be listed from high to low as Beautifil II (%35.72), Vertise Flow (% 28.88), Fuji II LC (% 21.09), Dyract XP (%17.60), and Filtek Z550 (% 16.58). As a result, in in‐vitro conditions gastric acid decreased microhardness while increasing the relative surface roughness of RDRMs.

Effect of Mouthwashes for COVID-19 Prevention on Surface Changes of Resin Composites

“…Water molecules enter the material's network between the polymer chains through hydrolysis causing the polymer chains to break into monomers and oligomers, resulting in surface hardness decrement. 22 , 24 The amount of water absorption depends on the composition of the resin composite and the reaction between the resin and the filler. 8 , 23 SonicFil 2 bulk fill resin composite had a greater statistically significant decrease in surface hardness.…”

“…There are a number of studies presenting the degradation of resin composites from drinks, beverages, and also mouthwashes. 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 However, there were no comparative studies of changes in surface hardness, surface roughness, and color of bulk-fill and conventional nanohybrid and nanofill resin composites resulting from preoperative disinfectant mouthwash used for prevention of COVID-19. Therefore, the aims of this study were to study the effects of various mouthwashes for COVID-19 prevention including 0.2% povidone iodine, 1% hydrogen peroxide, and 0.12% chlorhexidine on surface hardness, surface roughness and color changes of bulk-fill and conventional nanohybrid and nanofill resin composite materials, and to study the pH and titratable acidity of various disinfectant mouthwashes.…”

Effect of topical fluoride applications on residual monomer release from resin-based restorative materials

“…Clinicians decide on the material to be used in restorative dentistry depending on the patient's age, dentition type, cavity structure, depth, occlusal stress, and esthetic needs [ 20 ]. While nanohybrid composites are preferred in high-stress areas due to their high inorganic content and advanced mechanical/esthetic properties [ 21 ], bulk-fill composites are frequently preferred in deep cavities because they allow 4–6 mm spacing and reduce the number of clinical steps required [ 22 , 23 ]. Compomers are the most widely used materials for the restoration of primary teeth.…”

“…We attributed this higher release to the greater inorganic content in Z550 than in the other two resin-based materials. With the dissolution of larger inorganic content, the amount of degradation on the material surface may increase, resulting in higher monomer release from the resin matrix [ 21 ]. In the light of this result, the second null hypothesis, that there would be no difference in monomer release between the three different resin-based materials, was rejected.…”

The Effect of Gastric Acid on the Surface Properties of Different Universal Composites: A SEM Study

“…After the initial measurements were completed, the samples were exposed to 18 hours of simulated gastric acid solution and 6 hours of distilled water per day for 7-day (T2) and 14-day (T3) time intervals, and then, the microhardness and roughness measurements were repeated. Composite specimens were put into the glass Petri dish at 37°C for 14 days in 100% humidity in simulated gastric acid for 18 hours/day followed by 6 hours/day in distilled water [ 20 , 21 ]. Before the measurements, the specimens were washed in distilled water and blotted dried with absorbent paper.…”