[Restoration of endodontically treated teeth].

The existing literature on the criteria and conditions for the restoration of endodontically treated teeth has been reviewed. This review shows a consensus among the various authors that the restoration depends on: the dental structure which remains, the position of the tooth in the arch, and whether or not it has been used as a support for fixed or removable partial prosthesis. When the remaining dental structure is sufficient, the tooth can be restored, aesthetically and functionally in the usual way.

Upper molar dens in dente--case report.

The authors present a case report of dens in dente in an upper molar, in which endodontic treatment was impossible due to its location.

Effects of various irrigating solutions on the cleaning of the root canal with ultrasonic instrumentation.

The authors studied, in vitro, by light microscopy and by morphometric analysis, the cleaning capacity of Dakin's solution, water and Tergentol, when used as auxiliary solutions to ultrasonic instrumentation of root canals. After irrigation and instrumentation, 15 extracted human mandibular incisors, with a single root and with only one canal, were submitted to routine histological processing with serial 6-microns sections stained with hematoxylin and eosin. The results showed that Dakin's solution energized by ultrasound leaves root canals with less debris than Tergentol; water falls into an intermediate position.

A study of the dentinal permeability of the pulp chamber floor of human lower molars with separate roots.

The permeability of the dentin of the pulp chamber floor of lower molars with separate roots was studied, after instrumentation of the root canals by manual or ultrasonic techniques. The dentinal permeability was evaluated by the degree of penetration of copper ions in the tissue and quantified by methods used in morphometry. None of the combinations of irrigating solution/instrumentation technique caused an increase in the permeability of dentinal tissue in the pulp chamber region, probably because the dentin is reparative dentin, which is more amorphous and less tubular than primary dentin.

[Absorption capacity of different brands of paper points].

The absorption ability of paper points of different brands was assessed "in vitro". All points showed absorbing ability higher than 100 per center their own weight, but differences in moistening rate were detected among brands.

Fine structure and quantitative study in the otic ganglia of the rat.

Observations were concentrated on the ultrastructure of perikarya and satellite cells of the otic ganglion of the adult rat. Characteristics of both cell types were morphologically analysed as well as their relationship. Quantitative data concerning the volumetric density were calculated for the following elements of the ganglion: glial cells together (28.

[National training systems].

Implementation of the Plan of Action for the International Drinking Water Supply and Sanitation Decade in Latin American and the Caribbean will depend on the decision and will to act of the governments of the countries in the Region. It will involve the institutional development of the sector and the organizational development of the agencies responsible for providing those services, and require infusions of technical, financial and human resources. A supply of human resources from which to provide a work force of the required size and skills for the sector can only be achieved by knitting together the institutions involved in the training, development and utilization of those resources in a comprehensive nationwide system.