Barnices y adhesivos en el sellado de restauraciones con amalgama de plata / [Varnishes and adhesives in the seal of silver amalgam restorations]

The object of this paper is to evaluate the marginal filtration occurring between restoration/teeth in cavities filled with silver alloy when using different cavity varnish and adhesives. In 50 teeth removed as a result of decay, cavities were prepaired on vestibular faces and were divided into 5 equal groups: Group A: with no caviti varnish; Group B: two coats of a linkin agent (Scotch Bond 3M); Group C: an amalgam liner base (Voco); Group D; two coats of copal varnish: Group E: an amalgam bond base (Carl San Remo, Germany). All groups were filled with a silver alloy. The teeth were inmersed in a fuchsin solution at different temperatures (17.37 degrees C and 50 degrees C) for 20 minutes. Longitudinal cuts were made for visualization under a stereoscopic magnifying glass. Each group was observed by five odontologists and was classified according to four categories: Grade I: no filtration: Grade II: less than 1/3 wall filtration; Grade III: more than 1/3 wall filtration; Grade IV: filtration in walls and floor. Teeth with pulp filtration were discarded. Total and percentage values were determined for each analysed group. The results revealed that: Group A: 100

of samples corresponds to Grade IV. Group B: 40

of sample falls within Grade II while the rest corresponds to the highest grade. Group C: 30

belongs to Grade II, 60

to Grade III and the remaining 10

falls within Grade I, while the remaining 20

correspond to Grades III and IV, respectively. Group E: 50

for Grade I and the rest in Grade II.(ABSTRACT TRUNCATED AT 250 WORDS)

Scanning electron microscopy of cuticular surface of the adults Paragonimus heterotremus in Phitsanulok, Thailand.

Scanning electron microscope observation of surface structure was made on adult Paragonimus heterotremus (Phitsanulok, Thailand) and the surface topography of the anterior end, suckers, body cuticle and papillae was described. The numerous thorn-like tegumentary spines were distributed all over the surface. The spines were well-developed and branched. The papillae were divided into two types: dome-shaped and ciliated. Two pairs of papillae were seen around the lip of the oral sucker, while those around the ventral sucker were not evident.