Search

Background: Early caries lesions present a greater porosity in the deep layers than in the superficial layer of the enamel. The "white spot" lesion is a dynamic lesion which is subjected to the changes occurring in the oral cavity; it can regress, stabilize or progress. The aim of this study is to show if there are considerable morphological differences in the superficial ultrastructural aspect of early caries lesions, active or stabilized, in persons of different age., Methods: To carry out this SEM observation, 15 patients aged from 12 to 50 presenting early caries lesions have been selected. Some of them had been recently subjected to orthodontic treatment, others several years ago. Five of these patients have been called back to examine again the demineralized area by microscope in the very same place of the first observation. The replica technique was used utilizing a silicon-based impression material, an epoxy resin for replicas casting, little steel nets to fix the silicon material., Results: At the level of white spot lesions it is evident a tissural structure scattered with small overlappings and micropits with a diameter of 0.5-2 mu. The patients who removed orthodontic bands more than 10 years before show a shining white aspect, corresponding to the nearly complete loss of enamel perikymata with well defined abrasions, but without any micropits at SEM examination., Conclusions: The replica technique has shown to be useful to record the defects of active and stabilized caries lesions. However this technique can't be utilized as a diagnostic instrument because it would be too expensive, but it is certainly a valid support for in vivo research.

Modern clinical pathology is mainly based on the analysis of blood samples, carried out through more and more sophisticated techniques. Being the blood test an invasive technique, it certainly reduces the possibility of carrying out blood analysis, especially in patients such as children, old people, handicapped people and every person who needs continuous biochemical or pharmacological monitoring. In these cases it is very important to find other body fluids that can be easily obtained and that can offer the same reliable data as blood. Due to some of its characteristics, sometime saliva may be a good alternative to venous blood, as it presents the same features of plasma or urine. The chemical analysis of saliva provides some information that are useful for metabolic, inflammatory, neoplastic and genetic diseases; furthermore radioimmunological dosages allow to assess small concentrations of active substances. On the basis of an accurate review of literature, the aim of this study is to analyse the importance of saliva in diagnosing and monitoring certain systemic diseases, the utilization of saliva in hormonal and pharmacological dosages and the use of saliva in some epidemiological studies. Finally, it is emphasized that saliva in monitoring may help to manage several clinical conditions.

Background: Oxytalan fibers were identified by Fullmer and Lillie in 1958 for the first time, using the same coloring methods utilized for the elastic fibers. However, the istologic preparation had been previously treated with strong oxidation. Oxytalan fibers were found in many organs and tissues of different animal species and seem to be a type of "immature" elastic fiber in a precocious state of development. Anyway, the functional role of oxytalan fibers is still not clear. The oxytalan fibers, located in particular mechanical stress anatomic sides, seem to be connected to a more compact connective tissue in this sides. The purpose of our study is to analyze the anatomic arrangement of the oxytalan fibers in the temporomandibUlar joint of three different animal species: the rat [correction of mouse], the rabbit and the dog., Materials and Methods: Up to now, a coloring method specific for the oxytalan fibers has not been developed. Therefore, a correct evaluation of their presence requires a systematic approach in which two contiguous sections of a sample, one heavily oxidized and the other non oxidized, are compared., Results: Our results show the presence of the oxytalan fibers differently located depending of the animal species and the age of the animals.

An unusual case presenting congenital malformations involving the face and mastication apparatus is described. It has been classified as a mandibular-ocular-facial syndrome (Françise's"new syndrome".

The Authors have proposed to develop this research employing a preparation containing exclusively a cortisonic, the desametazone, in order to evaluate the alterations of the dentinogenesis to be attributed to such component. 32 cavities have been carefully drilled in dogs' cuspids. The 16 experimental cavities were dressed with desametazone, asbestos and amalgam in successive strata while in the 16 control cavities only asbestos and amalgam were used. Stainless steel bands were cemented on the processed teeth. The animals received 9 I.V. injections of tetracycline (10 mg per kg) each at 7 days interval. In the observation of the tetracycline markings under the experimental cavities (with desametazone) alterations of the dentinogenesis were not observed. Consequently, it seems that the action of desametazone is not to be considered harmful for the pulp tissue under the freshly cut dentine, as far as duration of the experiment is concerned.

Tetracycline labelling was employed to assess pulp and dentin reactivity to the use of oxyphosphate cement in the dog. A comparison was made of dentine conditions below control cavities and those containing the cement. In the former, the pulp and dentin response consisted of enhanced dentinogenesis, whereas in the latter this parameter showed no particular changes throughout the experimental period.

Odontomix (reg'd) cement was used at the bottom of cavities prepared in healthy dog canines in a attempt to prevent pulp and dentine alterations caused by the preparation and filling of cavities. 24 dogs were used along with 24 controls. I.v. tetracycline was afterwards given 10 times at weekly intervals. Examination of tetracycline labelling under the cavities showed that the cement caused pulp and dentine changes in confined areas, though it has not yet been possible to determine whether these are due to the corticosteroid, the antibiotic, or the excipient employed in the preparation.

An association of trimethoprim and sulphamethoxazol (Bactrim, Roche) was employed in the indirect capping of healthy teeth in the dog. Tetracycline labelling showed dentinogenesis in these teeth and comparison was made with the controls, A quantitative and qualitative change in dentinogenesis was noted below the control cavities. This alteration was less marked in Bactrim-treated teeth. It is deduced, therefore, that the operations involved in the preparation and filling of cavities in healthy teeth leads to pulp damage that can be partly prevented by using a bactericide.