Factors affecting dental biofilm in patients wearing fixed orthodontic appliances

Abstract

Background: The aim of this study is to investigate the amount and the distribution of biofilm in patients wearing fixed appliances and its relation with age, gender, frequency of tooth brushing, and patient motivation.

Methods: The sample comprised 52 patients (15.5 ± 3.6 years old, 30 females and 22 males) wearing fixed orthodontic appliances. Dental biofilm was assessed using a modified plaque index (PI). A questionnaire was used to collect patient's information, including gender, age, treatment motivation, and frequency of tooth brushing.

Results: Gingival (PI score = 0.9 ± 0.7), mesial (0.8 ± 0.6), and distal (0.8 ± 0.5) areas accumulated more biofilm than occlusal areas (0.3 ± 0.3) (P < 0.038). The maxillary lateral incisors (1.1 ± 0.8) and maxillary canines (1.0 ± 0.8) had more biofilm than other teeth (P < 0.05). The maxillary arch (0.8 ± 0.7) had significantly more biofilm than mandibular arch (0.6 ± 0.6) (P = 0.042). No significant difference was found between the right side (0.7 ± 0.7) and left side (0.7 ± 0.6) (P = 0.627). Less biofilm was found in females (0.6 ± 0.5), adults (0.3 ± 0.3), and "self-motivated" patients (0.3 ± 0.3), compared with males (0.9 ± 0.5), children (0.8 ± 0.6), and "family-motivated" patients (1.1 ± 0.5) (P < 0.001). The amount of biofilm was associated with self-report of the frequency of daily tooth brushing (P < 0.001).

Conclusions: Patients wearing fixed orthodontic appliances have the highest biofilm accumulation on the maxillary lateral incisors and maxillary canines, particularly in the gingival area and areas behind arch wires. Less biofilm was observed in female and adult patients and in those who were self-motivated and brushed their teeth more often.

Keywords: Biofilm; Dental plaque; Oral hygiene; Orthodontics; White spot lesions.

Fig. 1

Biofilm formation on the four areas of a tooth in relation to the bracket (G gingival, M mesial, D distal, O occlusal). The occlusal area accumulated the least amount of biofilm compared with the gingival, mesial, and distal areas (P < 0.038). No significant difference was found among the gingival, mesial, and distal areas (P > 0.132)

Fig. 2

Mean levels of biofilm formation on each tooth as indicated by the plaque index and a color-coded map

Fig. 3

Comparison of biofilm formation by sex, age group, and arch. Males had significantly more biofilm than females (P < 0.001). Children had significantly more biofilm than adults (P < 0.001). The maxillary arch had significantly more biofilm than the mandibular arch (P = 0.042)

Fig. 4

Biofilm formation in patients with different motivations to undergo orthodontic treatment. “Family-motivated” patients had more biofilm formation, followed by subjects who were “self- and family-motivated,” and “self-motivated” (P < 0.001)

Fig. 5

Biofilm formation in patients with different daily tooth brushing frequencies. A significantly association was found between the frequency of daily tooth brushing and the amount of biofilm formation (P < 0.001). Note the pronounced gradient showing less biofilm in patients reporting higher frequency of tooth brushing