1.Plaque control methods


**Figure 3.** *White spot lesion in individuals after orthodontic treatment.*

	- Mouth rinsing
	- By increasing enamel resistance to microbial acid with topical fluoride
	- Fluoride containing etchant
	- Fluoride containing bonding adhesives
	- Fluoride releasing modules

#### **5.1 Plaque control methods**

#### *5.1.1 Mechanical plaque control*

It is very important to use the right brushing technique to control dental plaque. Flossing as a modification of the standard toothbrush can help patients achieve oral hygiene. Compared to a manual toothbrush, using an electric toothbrush in conjunction with a manual toothbrush or regular washing with water could be a more effective way to prevent dental plaque. On the other hand, no evident superiority has been found for electric brushing [42, 43].

Bracket attachment with direct attachment exposes proximal surfaces to enamel demineralization due to the difficulty of maintaining oral hygiene with the archwires in place. Flossing has been proven to be helpful in interproximal cleaning. The floss threader would also be used to thread the floss under the archwire. The soft rubber interdental stimulator could also be helpful in interproximal cleaning and massaging the interproximal areas [44].

#### *5.1.2 Chemical plaque removal*

The material to be used for plaque removal by the chemical method should not support resistant microorganisms and should not be toxic in order not to disturb the balance of the oral microflora. Chlorhexidine antiseptic, one of the chemical plaque prevention methods, is the most effective, because of its absorption onto the acquired pellicle, which prolongs its presence and effect in the mouth.

Given these stringent requirements, it is surprising that any product has been developed as a chemical antiplaque agent. However, long-term use of chlorhexidine causes brown staining on the teeth.

Lundstrom and Krasse (1987) investigated the effect of chlorhexidine mouthwash on *Streptococcus mutans* in patients receiving fixed orthodontic treatment and stated that they found the use of chlorhexidine less beneficial [45].

#### *5.1.3 Reducing plaque retention by the appliance*

The larger the area covered by orthodontic attachments on the enamel surface, the more difficult it is to clean the remaining tooth surface. Archwire design also affects the build-up of plaque and food debris [5].

#### **5.2 The use of various agents containing fluoride**

#### *5.2.1 Mouth rinsing*

Two approaches have been developed to protect the enamel surface. The first is aimed at strengthening enamel and reducing acid solubility, that is, the use of topical fluoride agents during and after orthodontic treatment. The second involves the use of materials that protect the tooth surface around and below the orthodontic attachment with a protective coating [5].

In another study, mouthwashes containing 250 ppm fluoride twice a day were used to provide remineralization of the initial lesions on the approximal surfaces to patients undergoing orthodontic treatment. It has been reported that this method significantly increases remineralization [46].

Thuy et al. Lari, on the other hand, reported that the remineralization amount of solutions containing fluorine increased the effect of each other when used together with strontium (Sr) [47]. Tange et al. Lari stated in their *in vitro* study on primary teeth that when xylitol and sodium fluoride are used together, they increase the remineralization effects of each other [48].

#### *5.2.2 Increasing enamel resistance using topical fluorides*

The use of fluoride agents has been shown to be effective in preventing WSL formation. The use of fluoride in reducing caries; acting as a kind of catalyst that promotes the formation of high-quality hydroxyapatite; by assisting remineralization during pH fluctuations, it acts by inhibiting the glycolysis of plaque bacteria [49]. The cariostatic effect of topical fluoride is mainly based on calcium fluoride (CaF) depending on the formation. Oral hygiene maintenance combined with daily topical fluoride use has been shown to significantly reduce enamel decalcification.

In patients who have received fixed orthodontic treatment, high concentration fluoride application provides remineralization in the superficial layer of enamel, yet it is not effective in the deeper layers. Low-concentration fluoride application is recommended as it allows slower penetration of calcium and fluorine ions from saliva following orthodontic treatment [50].

Applying fluoride polishes to the tooth surface surrounding the bracket to protect the enamel surface from the acid attack has been suggested as another technique to prevent enamel demineralization [51]. A split-mouth design study reported that Ultraseal XT Plus clear sealant provided a significant reduction in enamel demineralization in individuals undergoing fixed orthodontic treatment. After the study, six lesions were observed on the sealant applied surfaces, while 22 lesions were observed on the non-applied surfaces. Of the teeth detected with white spots, 19 lesions (68%) were found in the maxillary arch, and nine lesions (32%) were found in the mandibular arch. The highest white spots were seen in maxillary laterals and canines without sealant. It has been stated that this product effectively seals the enamel surfaces adjacent to orthodontic brackets and resists mechanical wear and is recommended for use by clinicians [52].

In a study by Derks et al., it was observed that the use of toothpaste, gel, or these materials containing 1500–5000 ppm fluorine together with chlorhexidine can inhibit demineralization. It was observed that coating the brackets with polymeric material did not have an inhibitory effect on demineralization [53].

#### *5.2.3 Fluoride containing etchant*

Thornton (1986) et al. stated that the addition of fluoride to phosphoric acid etch had little or no protective effect in an *in vitro* study. Because it dissolves on the enamel surface and does not show any permanent effect when rinsed [54].

#### *5.2.4 Fluoride containing bonding adhesives*

Fluoridated glass ionomer and composite resin materials are used to reduce demineralization [55]. It has shown that glass ionomer cement protects the underlying enamel, as well as around an orthodontic attachment from decalcification. However, it has been shown that the glass ionomer has a weaker bond strength than the composite but the retention is sufficient [56].

#### *5.2.5 Fluoride releasing modules*

The study of Marini et al. [57] was carried out by placing an intraoral material that releases 0.04 mg of fluoride per day during the orthodontic treatment. It was observed that caries and white spot lesions did not occur within 6 months. In another study, it was determined that the lesions were reduced by 54% at the end of 4 weeks in those using a high amount of fluorine-containing topical gel (12,500 ppm F) and toothpaste (1450 ppm F), while there was a 44% reduction in those using only toothpaste. However, no statistically significant difference was found [58].

#### **5.3 Teeth whitening**

Teeth whitening demineralization is not a therapeutic method, however, if topical fluoride application does not produce the esthetic results desired by the patient after orthodontic treatment, vital teeth whitening should be considered. In white spot lesions, this process would make the lesions less apparent [50].

#### **5.4 Pit and fissure sealers**

It has been stated that light-curing pit and fissure sealants applied to the enamel surface adjacent to orthodontic brackets are effective in preventing enamel demineralization without the need for patient compliance. Benham and colleagues reported that micro-abrasion resistant and highly filled flowable composites greatly reduced white spot lesions when applied to pits and fissures [52].

Salar et al. examined 45 extracted third molars by dividing them into three groups. Conventional sealant without fluoride (Group 1), fluoride-releasing sealant (Group 2), or glass ionomer sealant with high fluoride release (Group 3). According to the results, ProSeal provided increased demineralization inhibition compared with a conventional sealant containing no fluoride, but less than that observed by a glass ionomer sealant [59].

### **5.5 Argon-laser tooth enamel surface weakening**

Argon laser can be used to prevent enamel decalcification by changing the crystal structure of enamel. It has been reported that when argon laser is applied to the enamel surface. Argon laser causes the surface properties of the enamel to change by creating micro-voids that stabilize the ions on the enamel surface during the acid attack. Phosphate, calcium, and fluoride ions in saliva could subsequently precipitate into these cavities, increasing the resistance of tooth enamel to demineralization and increasing mineral uptake from saliva [60].
