Effects of a new type of clear overlay retainer on occlusal contacts

Abstract

The popularity of clear overlay retainers (CORs) has increased recently because of their advantages such as better esthetics, cost effectiveness, easy fabrication, and good compliance. However, a deficiency in posterior occlusal settling is a reported limitation of CORs. The aim of this study was to evaluate the posterior occlusal contact changes in a new type of clear orthodontic retainer called Oral-treaper (OTP), which consists of three layers and has stronger mechanical characteristics than do conventional retainers. Three patients who completed fixed orthodontic treatment received OTP as a removable retainer. Cast models were fabricated after the removal of fixed appliances (T1) and after 4 to 11 months of using the retainers (T2). We evaluated all the cast models to compare the post-orthodontic settling pattern during the use of the OTPs. The depth of occlusal contacts was evaluated using color maps. The OTP did not prevent vertical settling in all patients but resulted in an improvement in posterior occlusal contact points.

Computerized Assessment of Occlusion and Muscle Activity during Use of a Multilayer Clear Retainer: A Preliminary Study

“…The increase in posterior force might be due to a vertical settling effect. This result might support our previous study, which showed the post-orthodontic settling in OTP with cast models [ 8 ]. Although all the incisal edges and occlusal surfaces were covered with removable retainers, the change of occlusion under retention period with OTP was different from that with VFR.…”

“…Two weeks later, they received an Oral-Treaper (OTP) retainer for the maxillary dentition and a tongue elevator for the mandibular dentition ( Figure 4 ). As described above, the OTP is a clear-overlay type retainer which is composed of three layers ( Figure 1 ) [ 7 , 8 ]. The outer layer is polyethylene terephthalate glycol (PETG), the middle layer is thermoplastic polyurethane (TPU), and an inner layer is a reinforced resin core.…”

“…To overcome these limitations, a new type of clear retainer was developed called the Oral-treaper (OTP) ( Figure 1 ) [ 7 , 8 ]. It is composed of multiple layers of polymers.…”

“…The inner layer does not extend to the second molars to ensure settling of those teeth. Kim et al [ 8 ] evaluated the settling pattern of patients during the use of the OTPs and showed an improvement in posterior occlusal settling. Most important in any study of settling patterns is the study methodology.…”

Force Distribution of a Novel Core-Reinforced Multilayered Mandibular Advancement Device

“…In addition, core integration contributes to the dimensional stability. The lateral wall of the appliance is well maintained without distortion or expansion, and thus, the arch width can be stabilized [ 45 ]. This may be the reason for the low force distribution of model 3 in our study.…”