An Ideal Retainer

An Innovative Approach to Retention: Thermoplastic Retainer.

AIM The aim of this study was to design and introduce a retainer that overcomes the common shortcomings seen in other retainers. MATERIALS AND METHODS Hard thermoplastic sheet of 0.5 mm thickness is vacuum or pressure-molded onto the patient cast. Lingual portion of the retainer is trimmed according to the contours of the anterior teeth. Contact points between the maxillary and mandibular ant...

An in vitro comparison between a bonded retainer system and a directly bonded flexible spiral wire retainer.

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...

Doctors' retainer scheme.

Biprojectivty of Banach algebras modulo an ideal

In this paper, we introduce the new concept of biprojectivity of a Banach algebra modulo an ideal, as a generalization of this notion in the classical case. By using it , we obtain some necessary and sufficient conditions for contractibility of Banach algebras modulo an ideal. In particular we characterize the contractibility of quotient Banach algebras. Also we study the relationship between t...

Coherence in amalgamated algebra along an ideal

Let $f: Arightarrow B$ be a ring homomorphism and let $J$ be an ideal of $B$. In this paper, we investigate the transfer of the property of coherence to the amalgamation $Abowtie^{f}J$. We provide necessary and sufficient conditions for $Abowtie^{f}J$ to be a coherent ring.