We make a review of the factors contributing to microleakage around dental restorations and the biological effects that this produces. We also make an evaluation of the existing methods for its research. We analize the behaviour of the different restorative materials, in relation to microleakage, and we set the rules to minimize this inevitable event that affects so much the longevity of dental restorations.

A scanning electron microscope study was made to study the morphological changes in the human enamel surface produced by low and high temperatures. Cracked dental enamel was observed when the teeth were exposed at low and high temperatures. When the time of exposition was increased, there are more enamel cracks which may be considered as enamel fractures.

We have compared the endurance recuperation to the fracture of class II cavities, OM and MOD, filled with amalgam or composite resin. The composite resin recuperates the tooth endurance in the MOD cavities and in the OM cavities. The teeth with small OM cavities filled with amalgam recuperate their endurance to the original compression but the teeth with MOD cavities filled with this material don't recuperate it.

The adhesive ability of Lactobacillus, Streptococcus mutans and Actinomyces viscosus-naeslundii on enamel, amalgam and composite of microparticle and small-particle are studied "in vitro". The selective mediums used for the three micro-organisms are, respectively, Rogosa agar, M.S.B. and C.F.A.T. The lower adherence is showed by bacterias of Lactobacillus genus. S. mutans and A. viscosus-naeslundii show similar adherence properties between them. The greatest adherence was obtained in composites, being S. mutans the bacteria with a greatest level of adherence to the composites of small-particle, and A. viscosus-naeslundii the bacteria with more adherence to the ones of micro-particle. The adherence on amalgam was slightly lower than the adherence on enamel.

Along this work, we study the salvage of resistance to pression of teeth with OM cavities and with an excavated top of the palate, when we obstruct it. We use composed resin or glass cement to fill up the excavated top in order to recover the outline of the OM cavity and we obstruct it with composed resin or combining glass cement with composed resin. Because any significant difference has been found between both kind of obstruction.

The aim of this paper is to offer an easy, accurate and aesthetical solution to the problem of the loss, by wastage, of anterior guides in those patients who show facets in initial stages of bruxism (central of peripheral). Using the acid-etch non-precious metals(Cr-Ni-Be) technique we make a metalic plaque covering the posterior face of the upper canines, on which we place a porcelain incisal rim. All of this is fixed with a composed material.

Antiinflamatories, antipiretics and analgesics of normal use with special interest in the salicylates that we considered analgesics of first election, excepting counter-indications are exposed. We expressed our conduct in the handling of the pain with the different alternatives according to the cases, to revitalise the use of aspirin in its different presentation forms, as an effective analgesic.

This paper is about the possible influence that the use of two different face archs on the transference of the upper model, should have in the later regulation of the semiadjustable articulator Arcon type.

Embrionary evolution of the tooth in the rat continues four times very clearly. The first of them or "dentair esbozo" it takes place about the 16th day. The second one of them or "caperuza time" between the 17th and 18th day. The third one of them or "bell time" it takes place 19th, 20th and 21th days. At the end the fourth one of then or "of resolution" it takes place the 22 and first of the afterborn days.