Table2: ANOVA test for the comparison between different media.

Descriptive statistics

The results of mean values, standard deviations (SD), maximum (Max.) and minimum (Min.) of surface roughness of each group presented in Table 1. The surface roughness values of tested samples expressed in nanometer (nm).

Table 1: Descriptive statistics of surface roughness of different groups.

group while the highest values of surface roughness were found during immersion in fluoridated mouthwashes (Sidra Zac) means that it was the most aggressive agent on esthetic arch wires. The Post Hock Tukey’s test Table 3 has shown the statistical difference was between as received-Sidra Zac and between distilled water-Sidra Zac after 3week immersion period. In 6 weeks immersion period the significant difference was between as received- Biofresh, as received -Sidra Zac, distilled water- Sidra Zac and Biofresh- Sidra Zac.

B-Comparison between immersion period

ANOVA test was used Table 4 and Figure 3 which illustrated that the surface roughness doesn’t change significantly in distilled water with time, as the distilled water is not an aggressive media in contrast to Biofresh in which the surface roughness increases significantly after 6 weeks. While in Sidra Zac mouthwashes, the surface roughness increases significantly after 3 weeks as the roughness values increases by the time. Post Hock Tukey’s test Table 5 illustrated the significant difference was between 1 week- 6 weeks and between 3 weeks- 6 weeks in both types of mouthwashes.

Figure 3. surface roughness values in different immersion periods.

Table 3: The Post-hoc Tukeyâ??s test after ANOVA test.

Table 4: ANOVA test for the comparison between immersion periods.

Table 5: The Post-hoc Tukeyâ??s test after ANOVA test.

Discussion

Compromised oral hygiene one of the major drawbacks of orthodontic treatment, this results in demineralization of the enamel, white spots, and caries. Periodontal problems may develop in some patients while undergoing orthodontic treatment, necessitating the use of different mouthwashes to reduce plaque accumulation [15].

Roughness refers to the surface's texture and how it interacts with its surroundings. It is distinguished by its amplitude (vertical), spacing (horizontal), and hybrid parameters. Materials, coatings, manufacturers and manufacturing techniques have all shown to influence archwire surface structure [16]. The most significant effect is that of surface roughness. Plaque accumulation is accelerated by increasing surface roughness and free surface energy. In the leveling stage, lower friction improves the sliding movement between the wire and the bracket resulting in faster tooth movement, less wasted force, and better anchorage control [17].

Surface profilometry was the primary method for investigating surface roughness, a technique in which a tiny tip was used to scan the topography along a single line in a predetermined area. The main disadvantage of this technology is that it is an invasive method, as well as, surface defects next to the scan line cannot be measured. As a result of the growing demand for nondestructive and noninvasive procedures, novel analysis approaches had developed atomic force microscopy (AFM) based on an optical method.

In this research, the surface roughness of orthodontic wires was assessed qualitatively using the AFM technique. The AFM is a type of scanning probe microscope that collects information on detected surfaces by using interatomic interactions. AFM uses a sensor, which is a sharp point that interacts with the specimen surface to create image [18]. This method is non-invasive and only necessitates a small amount of sample preparation. Furthermore, the AFM technique produces simultaneous 2-D and 3-D images, allowing specimens to be re-evaluated without damage [17].

This study investigated the effect of fluoridated and nonfluoridated mouthwashes on surface roughness of Teflon esthetic archwires in comparison to distilled water which used as control media. It is found that the surface roughness of Teflon archwires has been increased with time in both types of mouthwashes in comparison to distilled water. The increased roughness in fluoridated mouthwashes is most likely the result of topical fluoride's corrosive effect on titanium-based orthodontic archwires. Because of titanium's high affinity for hydrogen, degradation and loss of the oxide film on the surface, the underlying alloy will be exposed, resulting in corrosion and absorption of hydrogen ions from the aqueous-based solution. The diffusion of hydrogen through interstitial sites, dislocations, and grain boundaries reacting with lattice atoms to form hydride phases, particularly titanium hydride, has been proposed to explain hydrogen absorption and associated embrittlement of titanium-based alloys. Titanium hydrides have been observed to establish a bodycentered tetragonal structure, which is thought to be the source of the alloy's surface property degradation [15,19]. The present study agrees with [20] who stated the fluoridated mouthwash change the surface morphology of coated arch wires. Also, in agreement with [14] who concluded both the neutral and the acidulated phosphate fluoride agents cause corrosive changes in surface topography.

In Biofresh mouthwashes the increased roughness may attributed to low PH and increased acidity which cause the destruction of protective layer, this resulted in increased hydrogen peroxide penetration. In addition, Hydrogen peroxide can cause the release of large amounts of OH radicals in metal surfaces which has the potential to cause Ni-Ti wire surface layers to be damaged [21]. This study in agreement with [22] who reported that soft drinks with a low PH level have been found to corrode the surface of Ni-Ti orthodontic arch wires in different ways depending on the surface pattern.

The increased surface roughness cannot be attributed to Chlorohexidine component, as chlorhexidine-containing mouth rinses may be prescribed as non-destructive prophylactic agents [23]. Due to the presence of fluoride ion with increased acidity in Sidra Zac mouthwash, the surface roughness was higher in comparison to Biofresh mouthwash which has low PH, because the effect of Fluoride and PH together is stronger than the effect of low PH only on surface roughness [24]. In our study, the maximum exposure time was 6 weeks. The exposure time may differ in clinical situations. Mastication and the oral environment may also affect the layer of orthodontic wires. However, this effect was not assessed in this in vitro test. We used one type of orthodontic arch wires that were clinically available. Despite their comparable composition, wires from different manufacturers may have varied surface roughness.

Limitations of the Study

As it is an in-vitro study it is difficult to simulate the actual oral conditions such as oral hygiene habits, oral pH, biological variables, the duration of intraoral exposure, and the physical and chemical properties of ingested food and liquid. This is in contrast to the clinical circumstances when the wire was exposed to chemical solutions while being ligated into brackets on misaligned teeth. In this situation, the arch wires developed a significantly increased rate of surface roughness in comparison to non-deflected arch wires.

Conclusion

The surface roughness of Teflon esthetic Ni-Ti orthodontic arch wires was investigated using 1 week, 3 weeks and 6 weeks immersion periods in two types of mouthwashes which included fluoridated and nonfluoridated mouthwashes. The immersion media and immersion time had a statistically significant influence on surface roughness variation. In sidra Zac mouthwash, the significant increase in surface roughness values obtained after 3 weeks immersion period. In Biofresh mouthwash, the significant increase in surface roughness obtained after 6 weeks immersion period. According to this study the Teflon arch wires can be left inside the patient mouth who takes the non- fluoridated mouthwash for longer period than the patient who uses a fluoridated mouthwash. Thus, when evaluating the effectiveness of arch-guided tooth movement, the increase in surface roughness of Ni-Ti orthodontic arch wires in commercial fluoride-containing environments and acidulated mouthwashes should be considered.

Funding

Self-funded.

Conflict of Interest

None.

Acknowledgements

Authors are grateful to ministry of science and technology for accomplishing the measurement task.

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