Avaliação do selamento marginal de obturações de canais radiculares variando-se a proporção pó/líquido do cimento N-Rickert / Evaluation of marginal sealing on root canal fillings with different proportions of power and liquid of N-Rickert cement

Foi medida a permeabilidade marginal da obturação de canais radiculares realizada em dentes humanos "in vitro". Observou-se que as diversas proporções pó-líquido permitem infiltração do corante de azul de metileno em diferentes profundidades na interface dentinária apical/material obturador. A relação pó/líquido 0,4524/0,1 ml foi a mais eficiente, sendo estatisticamente significante

[Use of Solcoseryl DAP after nasal septum surgery]. / Zastosowanie preparatu Solcoseryl DAP po operacjach przegrody nosa.

Solcoseryl is a biological agent, which accelerates the healing tissue procedure. This influence was studied during the nasal septum surgery. In 25 patients the postoperational nasal plug was inserted with the Solcoseryl and in 10 (control) with the paraffin. The cytologic verifications were performed before and after the surgery. In the solcoseryl group the mucosa regeneration procedure was accelerated and the inflammation reduced.

The risk of intentional dissolution of the smear layer after mechanical preparation of root canals.

The root canals of 27 caries-free human cuspids were divided into 3 groups of 9 teeth each. Group I was mechanically prepared with reamers and files. Alternate irrigation with 5.25% NaOCl and 3% hydrogen peroxide was used between each instrument. The group II root canals were prepared with the use of alternate irrigation with the same concentrations of NaOCl and hydrogen peroxide and finally flushed with 17% EDTA and NaOCl solution. Group III was prepared mechanically with the use of sterile distilled water as an irrigant followed by a final flush with 17% EDTA solution. The root canals of all specimens were obturated with gutta-percha points and Tubliseal by means of the lateral condensation technique. After the root canals were obturated, samples of each of the three groups were immersed in separate flasks containing Streptococcus mutans, Staphylococcus epidermidis, and Corynebacterium hofmannii. All the microorganisms tested invaded the coronal dentin--where the access cavity had been sealed with Fynal--and/or the main foramen.

Microconservative restorations for approximal carious lesions.

The availability of new restorative materials such as glass ionomers, which have an anticaries action, prompts a reevaluation of some of the basic principles of restorative dentistry. It seems that conventional methods of treating the approximal carious lesion are too radical and that microconservative techniques offer a simpler, more effective solution when correctly applied.

[Resin and glass-ionomer sealants. Indications, mechanism of action, and application technics]. / I sigillanti in resina ed al cemento vetro-ionomerico. Indicazioni, meccanismo d'azione e tecniche di applicazione.

The usefulness and indications to treatment with sealants in pedodontics are examined. Sealants are classified and the action mechanism of sealant resins and the application techniques needed for correct positioning of the material are described. The use of the new glass-ionomer cement sealants, with their advantages and disadvantages, are then discussed and the preventive and economic value of occlusive seals evaluated.

Efficacy of dentin-bonding agents in relation to application technique.

The gap-reducing efficacy of two dentin-bonding agents was examined in butt-joint dentin cavities prepared in extracted human teeth. The cavity wall and the surrounding dentin surface were treated with one of the dentin-bonding agents, and a light-activated microfilled restorative resin was either applied and polymerized or applied and then withdrawn from the cavity and once again applied before polymerization. Ten minutes after polymerization the width and the extent of the contraction gap were measured, using a light microscope, approximately 0.1 mm below the original free surface of the fillings. The marginal porosity was also registered and calculated in percentage of the total filling periphery. It was found that reapplication resulted in an increased marginal porosity and also that the width and extent of the contraction gap were increased when the restorative resin was reapplied.

Bactericidal efficacy of metronidazole against bacteria of human carious dentin in vivo.

The bactericidal efficacy of metronidazole (MN) against bacteria of carious dentin was estimated by measuring bacterial recovery with or without application of MN to dentinal lesions in vivo. More than 10(3) colony-forming units of bacteria per milligram of sample were recovered from the samples of carious dentin. However, none were recovered from the samples of dentinal lesions which had been covered by alpha-tricalcium phosphate (TCP) cement containing MN in situ for 1 day, 1 month, 1 year and/or 2 years in vivo. Placebo experiments in which carious dentin was covered by TCP cement without MN showed that TCP itself was not bactericidal. Bactericidal efficacy of MN in situ is clearly demonstrated, indicating that MN is a valuable material in caries treatment to disinfect carious dentin.

Cyanoacrylate ester adhesive: a versatile tool in experimental surgery.

Cyanoacrylate ester adhesive is useful in experimental surgery in rodents and other animals for closing skin and muscle incisions, securing cannulae in place, and securing dental acrylic to bone. Both laboratories reporting here found independently that the technique used in applying cyanoacrylate for wound closures is important. Very small droplets of adhesive must be applied. A device for this purpose is described.