After completion of orthodontic treatment, a retention phase is required to prevent relapse of tooth malposition. Fixed retention in the mandibular anterior region is commonly used. This type of retainer is bonded to the lingual surfaces of the canines and incisors and may hinder oral hygiene, thereby promoting bacterial plaque accumulation and gingival inflammation.
Currently, probably due to the increasing use of clear aligner therapy, clear removable Essix-type retainers are becoming more widely used. Since these retainers can be removed by the patient, they may facilitate oral hygiene. However, studies assessing gingival health and the composition of the subgingival microbiota in patients wearing orthodontic retainers remain scarce.
Therefore, the aim of this study will be to assess the composition of the gingival sulcus microbiota and gingival health in patients wearing fixed or removable orthodontic retainers.
Ten adult patients who have completed orthodontic treatment will be recruited and divided into two groups:
1. Fixed retention group. 2. Removable retention group.
Periodontal parameters will be assessed, and bacterial plaque samples will be collected from the gingival sulcus at five time points:
T0: Bracket removal and dental scaling appointment. Periodontal parameters will be assessed, and plaque samples will be collected before bracket debonding and dental scaling.
T1: Retainer placement appointment, three days after T0. Periodontal parameters will be assessed, and plaque samples will be collected before retainer placement.
T2: One month after retainer placement.
T3: Three months after retainer placement.
T4: Six months after retainer placement.
Treatment involving both dental arches
Permanent dentition with at least 24 teeth
Treatment duration longer than 12 months
Treatment using the Versatile MBT system with a 0.022-inch slot
Patients with systemic disease or taking medications that may affect periodontal health
Inadequate restorations or active carious lesions
iodontal disease
Plaque index greater than 20% before placement of the retainer or during the study