Effects of Antiseptics and Fluorides on Orthodontic Archwires

Patient selection:

This study was carried out upon 18 patients (36 samples), all patients were selected from the outpatient orthodontic clinic, Faculty of Dental medicine, Al-Azher University, Assiut branch.

All patients were in orthodontic treatment with 0.022-inch Roth fixed orthodontic appliances. The subjects presented to the orthodontic clinic were assessed for eligibility according to the following inclusion and exclusion criteria.

Inclusion Criteria

1. Age range: Patients aged 15-28 years, ensuring adequate oral hygiene compliance and have ability to follow standardized oral hygiene instructions and use the assigned antiseptic or fluoride agent as instructed.
2. Orthodontic treatment status: Patients undergo fixed orthodontic treatment using pre-adjusted edgewise appliances.
3. Oral health status: Good general oral health, Absence of active periodontal disease, and untreated dental caries.
4. Systemic health: Medically healthy individuals with no systemic diseases affecting saliva composition or oral tissues, nor using medications known to affect salivary flow, pH, or oral microbial flora during the study period.

Exclusion Criteria

1. Systemic diseases such as diabetes mellitus, autoimmune disorders, or conditions affecting salivary secretion or oral mucosa.
2. Pregnancy or lactation, due to possible hormonal influences on saliva and oral tissues.
3. Poor oral hygiene or lack of compliance with oral hygiene instructions.
4. Allergy or hypersensitivity to nickel, stainless steel, fluoride, chlorhexidine, or any antiseptic agents used in the study.

Study design. The current in vivo study was randomized clinical intervention study to evaluate the use of antiseptics and fluorides on properties of nickel-titanium and stainless-steel arch wires during orthodontic treatment.

Ethical considerations:

The research project was explained both verbally and in writing and the objectives of the study were discussed with the patients and parents and a consent form for patient participation in the research project was obtained before starting the study.

The local ethical committees approved the research, with written informed consent provided by the subjects (Ethical Committee of the Clinical Hospital Centre Rijeka No. 2170-29-02/1-14-2 and Ethical Committee of the Al-Azhar University, Faculty of Dental Medicine No(AUAREC202300006-09).

Sample size calculation:

Based on previous studies (94) and Using G power statistical power Analysis program (version 3.1.9.4) for sample size determination, A total sample size (n=36) was sufficient for each group (12) in the study to detect a large effect size (f)= 0.980 between matched pairs, with an actual power (1-β error) of 0.8 (80%) and a significance level (α error) 0.05 (5%) for two-tailed hypothesis test.

Group Randomization:

Patients who met the inclusion criteria were randomly divided and allocated into three groups. Each group consisted of 12 samples: The process of randomization and group allocation was undertaken using online software: http://www.randomlists.com.

Group (1): (Teeth brushing group) Group (2): (Chlorhexidine group) Group (3): (Fluoride group)

Study groups:

Group I (Teeth brushing group) as control group:

Consisted of 6 patients who were instructed to make regular oral hygiene with a toothbrush and toothpaste containing a low concentration of fluoride, as commonly recommended for patients in orthodontic treatment, for one month.

Group II (Chlorhexidine group):

Consisted of 6 patients who were instructed to use chlorhexidine mouthwash for one month.

Group III (Fluoride group):

Consisted of 6 patients who were instructed to use fluoride antiseptic for one month.

• Each group (group I, group II and group III) will be subdivided into two subgroups, (Ni Ti group) and (St St group).
• (Ni Ti group): which consists of 6 patients which have Ni Ti wire in one arch.
• (St St group): which is consisted of the same patients of group A but have St St wire in opposing arch.

Materials and devices used in the study:

1. Orthodontic composite (Green Gloo), Ormco, USA
2. Orthodontic brackets (Smart Brackets, Roth prescription, 0.022-inch slot) Easyinsmile, Passaic, New Jersey, USA
3. Nickel-titanium archwires Easyinsmile (USA) International Corp., Richardson, TX, USA
4. Stainless-steel archwires Easyinsmile (USA) International Corp., Richardson, TX, USA
5. O-ties Matt Ortho
6. Signal Cavity Fighter toothpaste Manufactured in Egypt; trademark owner: Unilever PLC, England
7. Orovex antiseptic mouthwash Macro Group Pharmaceuticals, Egypt
8. DG fluoride mouthwash Al Esraa Pharmaceuticals, Egypt
9. Scanning Electron Microscope (JEOL JSM-6360LA) JEOL, Japan
10. Modulus of elasticity testing machine (AGS-X2 series) Shimadzu Corporation, Kyoto, Japan
11. Wilson (microhardness tester), Tukon 1102 \& 1202 Knoop/Vickers Hardness Tester - Buehler MicroMet 6000 series.
12. Friction tester machine (Model LRX-plus; Lloyd Instruments Ltd., Fareham, UK)

Collection of samples:

After 6 months of leveling and alignment using (0.014-inch and 0.016-inch) NiTi archwire and (0.016 * 0.022-inch) NiTi, Stainless steel and NiTi archwires with dimensions (0.016 * 0.022-inch) were placed intraorally at upper and lower arch, respectively and left in place for 30 days.

All NiTi wires were composed of w(Ni) ¼ 50.4% and w(Ti) ¼ 49.6%. The archwires were subjected to testing and analysis. Three experimental groups were formed, with 12 randomly assigned samples each.

All study participants were instructed on the uniform brushing method (Charters technique, three times per day for 2 minutes).

The first group consisted of subjects who conducted regular oral hygiene with a toothbrush and toothpaste containing a low concentration of fluoride (1450 ppm), as commonly recommended for patients in orthodontic treatment, for the whole study period of one month (the saliva group).

The second and the third groups used adjuvant oral hygiene products for one month: the second group brushed their teeth three times per day, once without toothpaste and twice using toothpaste and mouthwash with 0.12% chlorhexidine digluconate twice per day.

while the third group brushed their teeth three times per day, once without toothpaste and used mouthwash with of sodium fluoride for 30 days.

Methods of evaluation:

1. Hardness evaluation: - The hardness test was performed according to the rules and procedures defined by ASTM International. This device is a Vickers microhardness tester manufactured by Wilson Hardness.by applying a 100-g force for 20 seconds. Samples of archwires were cut to approximately 1.5-2 cm in length and fixed with cyanoacrylate on the sample holder. Four indents per sample were made and took the average.

2. Roughness evaluation: - Samples of archwires were cut to approximately 1.5-2 cm in length and its surface was cleaned with 95% ethanol. Surface examination was performed under secondary electron imaging (SEI) mode at Accelerating voltage: 5 kV, Working distance (WD): 11 mm, and Magnifications: x200, x1000 Representative samples of all archwires were selected for SEM evaluation (SEM-QUANTA FEG-250) to assess the surface homogeneity with various media in comparison to as received wires. The orthodontic archwire pieces were fixed on aluminum stubs with standard diameters using carbon double sticky tape. The samples were metallic and did not require coating as it is easily conducted with the use of SEM electrons.

   The high-resolution SEM images were analyzed using Image J 1.54g software to inspect the surface roughness and quantify the results for further statistical analysis.

3. Modulus of elasticity evaluation: - The flexural modulus of (0.016 × 0.022-inch) rectangular orthodontic archwires was determined using a universal testing machine (Shimadzu AGS-X2 Series, Shimadzu Corporation, Kyoto, Japan). The three-point bending test was performed in accordance with the recommendations of ISO 15841 for orthodontic wires.

   A three-point bending fixture consisting of two lower cylindrical supports and a centrally positioned rounded loading nose was mounted on the testing machine. The distance between the supports is fixed and is 10 mm (The span length (L) between supports was set at 10 mm, in accordance with ISO 15841 (2014).

   Straight segments (25-30 mm in length) were cut from each archwire using a carbide cutter to avoid edge distortion. Each specimen was positioned horizontally on the supports, with the 0.022-inch dimension oriented vertically to simulate standard clinical orientation. Careful alignment ensured that the loading nose contacted the midpoint of the specimen. Testing was conducted at a constant crosshead speed of 1 mm/min.

4. Friction evaluation: - A metal bracket with a 0.022 inch × 0.028-inch slot, 11° angulation, and 0° torque, was used. Brackets were cemented to rectangular metal block (50 mm × 20 mm × 6 mm). All samples were individually mounted on a computer-controlled materials testing machine (Model LRX-plus; Lloyd Instruments Ltd., Fareham, UK) with a loadcell of 5 kN and data were recorded using computer software (Nexygen-MT; Lloyd Instruments).

Samples were secured to the lower fixed compartment of testing machine by tightening screws. A wire was ligated to the bracket and attached to the upper movable compartment of testing machine then pulled out at the crosshead speed of 5 mm/min up to a distance of 5 mm.

The maximum static friction force was set as the maximum value during the first movement. The kinetic frictional force was set as the average value of the frictional force when the wire was moved by 1-5 mm recorded using computer software (Nexygen-MT; Lloyd Instruments). Friction force was recorded in gram

Statistical analysis:

Statistical analysis was performed with SPSS software (version 20; IBM, Armonk, NY). The mean and standard deviation values were calculated for each group. Data were explored for normality using Kolmogrov-Smimov and Shapiro-wilk test, showed parametric (normal distribution).

A paired t-test was used to study the differences between the variables intragroup, one-way ANOVA was used to study the differences between the variables intergroup.