[Corrosion of a dental acrylic resin by alkaline peroxide used for cleaning]. / Corrosion d'une résine acrylique à usage dentaire par un peroxyde alcalin proposé pour son entretien.

Some clinical observations have brought the authors to suspect a corrosion of acrylic resins by an alcaline peroxide (Steradent) proposed as a denture cleanser. By way of a laboratory simulation they have shown that standardized samples of Lucitone 199 are corroded by the main active agents issuing from Steradent: oxygen and a high level of alcalinity. A daily use of Steradent can thus badly affect the physical properties of denture acrylic bases.

[Maintenance of removable dentures. Nonexhaustive review of methods and current products]. / Entretien des prothèses amovibles: revue non exhaustive des méthodes et produits proposés.

The authors review various methods advocated to clean and disinfect removable prostheses. The effectiveness of most commercial preparations is quite relative, and some of them present definite risk for the appliance. Regular brushing of the prostheses remains absolutely necessary; it may be made easier but cannot be replaced.

[The "retention complex" and its relationship to abutments: what is today's thought?]. / Le "complexe rétentif" et ses rapports avec les dents piliers: qu'en penser aujourd'hui?

Based up on a review of the literature, the authors have tried to define the possible responsibility of each component of a retention complex (occlusal support--cross-piece--locking arm--retention arm) in the mechanical mobilisation of abutment teeth supporting partial removable prostheses (Kennedy, Class I and II). Taken separately, all these components are intrinsically able to mobilise the teeth. However, no "modern" retention complex (Nally & Martinet--R.P.I.--R.P.A.--"equipoise"...) should jeopardize the abutments, as long as they have been correctly prepared as well as the entire prosthesis.

The effect of three processing cycles on some physical and chemical properties of a heat-cured acrylic resin.

Samples were tested by following three processing methods: two processing cycles recommended by the manufacturer and quick violent boiling. Samples processed by following the recommended cycles showed statistically significant differences with regard to impact strength and Brinnel hardness, but without differences in the expected clinical behavior of the resin. Residual monomer ratio was higher when the boiling point was not reached, which seems to confirm the plasticizing effect of residual monomer. Samples were less brittle and less hard. Violent boiling increased porosity and lessened impact strength.

[Retention and biomechanics in the "retentive complex". 1. The schools of Akers, Roach and Ney]. / Retención y biomecánica de los "complejos retentivos". I parte: Las escuelas de Akers, Roach y Ney.

The authors remind the original principles having led Akers, Roach and Ney in the conception of their "retentive complexes" and analyse the main biomechanical concepts included in their propositions.