This work explores the performance of different silicon retainer ring designs when integrated into silicon micro-turbines (SMTs) incorporating thrust style bearings supported on 500 μm diameter steel balls. Experimental performance curves are presented for SMTs with rotor diameters of 5 mm and 10 mm, each with five different retainer designs varying in mechanical rigidity, ball pocket shape and...

INTRODUCTION We aimed to compare the shear bond strength (SBS) of three different retainer wires and three different bonding adhesives in consideration of the pretreatment process of enamel surface sandblasting. METHODS 400 extracted bovine incisors were divided into 10 groups of 20 paired specimens each. 10 specimens of each group were pretreated by enamel sandblasting. The retainer wires Bo...

OBJECTIVE To test the null hypothesis that orthodontist characteristics and factors related to retainer choice do not influence the management of the retention phase with regard to frequency and duration of follow-up care provided. MATERIALS AND METHODS Orthodontists (n  =  1000) were randomly selected to participate in an online survey divided into three categories: background, retainer choi...

Some recent results are reviewed that lead us now to believe that accretion discs are basically always magnetised. The main components are Balbus-Hawley and Parker instabilities on the one hand and a dynamo process on the other. A mechanical model for the Balbus-Hawley instability is presented and analysed quantitatively. Three-dimensional simulations are discussed, especially the resulting mag...

Clear thermoplastic retainers have been widely used in daily orthodontics; however, they have inherent limitations associated with thermoplastic polymer materials such as dimensional instability, low strength, and poor wear resistance. To solve these problems, we developed a new type of clear orthodontic retainer that incorporates multi-layer hybrid materials. It consists of three layers; an ou...

Bonded lingual retainers are becoming more popular to stabilize the results of orthodontic treatment. The in vitro shear strength of a flexible spiral wire (FSW) retainer (Zachrisson, 1977, 1983) bonded with Prisma Fil was compared to the 'A'-Company bonded lingual retainer system, bonded with either Concise or Right-On, to human enamel. Statistical analysis of the results showed no significant...

The present article describes a new product for long-term retention of the lower dental arch. The LingLock is a fixed bonded retainer from canine to canine in the lower front made up of separate, but co-working retention elements in the ceramic material aluminium oxide (Al2O3). The LingLock retainer enables the patient to floss the teeth in a regular manner in the actual retention area.

In this clinical report, we discuss the length of service and subsequent replacement of a maxillary anterior 2-unit cantilever fixed partial denture (FPD). The FPD provided 53 years of service to the patient and was finally replaced with a 2-unit porcelain-fused-to-metal (PFM) FPD. The original prosthesis replaced a missing maxillary lateral incisor using a partial coverage metal retainer, wher...