A comparison of apical sealing and extrusion between Thermafil and lateral condensation techniques.

Forty curved canals from 20 mesial roots of extracted human mandibular molars were instrumented (Profile .04) using a crown-down technique and divided into two groups. The experimental group was obturated using the Thermafil technique and the control group was obturated using the lateral condensation technique. Topseal sealer was used in both groups. Apical extrusion was recorded. Two molars were used as control teeth. All specimens were stored in 100% humidity for 1 wk, coated with nail polish, except for the apical 2 mm, and were suspended in black India ink for 48 h. Molars were decalcified, rendered transparent, and linear dye penetration was measured. Linear dye leakage and apical extrusion between the techniques were not statistically different (Mann-Whitney U test).

In vitro inhibition of marginal caries-like lesions with fluoride-containing amalgam.

Carious lesions surrounding restorations represent one of the main causes of restoration failure. The addition of fluoride compounds to dental restorative materials prevents or reduces recurrent caries. The purpose of this study was to compare the capacity of three restorative materials to inhibit the development of recurrent caries in vitro. Thirty unrestored, noncarious premolars that were being extracted for orthodontic reasons were sectioned in half buccolingually and divided into three groups. One of the groups was restored with conventional amalgam. The second group was restored with a fluoride-containing amalgam, and the third group was restored with a glass-ionomer cement. All the samples were submitted to a medium containing Streptococcus mutans (Ingbritt strain) for 8 weeks. At the end of the 8-week incubation period, the samples were cut into 100 microns sections, soaked in Quinoline (IR = 1.62), and observed with light transmission and polarized light microscopy. The development of artificial caries in the cavity walls was measured in microns. The results show that conventional amalgam had an average caries penetration of 160 microns, fluoride-containing amalgam 46 microns, and glass-ionomer cement 11 microns. Glass-ionomer cement gave the best protection against recurrent caries.

[Analysis of the in vitro antibacterial action of a fluoridated amalgam]. / Analisis de la acción antibacteriana in vitro de una amalgama fluorada.

To a conventional silver amalgam alloy was added 1% of stanous fluoride, to prove in vitro, if it presents any antibacteria actions against S. mutans and Lactobacillus acidophilus. Thirteen Petri plate were seeded with S. mutans and 12 Petri plate with Lactobacillus, in both cases, was disposited fluoride containing amalgam and conventional amalgam. The average of inhibition signs in the Petri plates with S. mutans was 1.7 mm in the Petri plates with Lactobacillus the average was 2.4 mm. Is demonstrated that the fluoride containing amalgam has in vitro antibacteria action in comparison with conventional amalgam, that has none.

[Fluoridated amalgams. Bibliographic review]. / Amalgamas fluoradas: revision bibliografica.

A review on fluoride containing amalgam is reported in this paper. The inhibitory effects of fluoride on dental caries are well known for many years. Thus, the incorporation of fluoride to an amalgam restoration prevents the occurrence of marginal caries. Other physical properties of fluoride amalgams such as compressive strength, dimensional changes, creep and corrosion are also reviewed in this paper.