Estudo comparativo da resistência à fratura de pré-molares superiores íntegros e restaurados com amálgama aderido

Abstract

The purpose of this in vitro study was to determine the fracture resistance of upper premolars which had received class II preparations (conservative and extensive) and were restored with bonded amalgam, with two different adhesive systems. Seventy teeth were divided in four groups: group 1 (control), with ten sound teeth; group 2, with twenty prepared teeth (10 teeth received conservative cavities and 10, extensive cavities) restored with amalgam without any kind of liner; groups 3 and 4, similar to group 2, though with linings of glass ionomer cement (Vitrebond - 3M) (group 3) and dental adhesive (Scotchbond Multi-Purpose Plus - 3M) (group 4). The teeth were previously fixed in PVC cylinders with acrylic resin. After being restored and thermocycled, the test specimens were submitted to fracture by means of compression in an EMIC-MEM 2000 universal testing machine. After the application of the analysis of variance and complementary Tukey's test, we concluded that the utilized adhesive systems produced an increase of the fracture resistance of teeth presenting with conventional cavities; the teeth presenting with conservative cavities were more resistant in all experimental situations.

Evaluation of compressive strength in the first premolars between young and elderly people: ex vivo study

“…In our experiments, the mean of compressive loading on the teeth of young and elderly was 103.2 kgf. No statistically significant differences were found when compared to the results of Minto et al 29 (t = 0.371, df = 29, p-value = 0.713).…”

“…No statistically significant differences were found when compared to the results of Minto et al. 29 ( t = 0.371, df = 29, p ‐value = 0.713).…”

“…Minto et al. 29 analysed intact maxillary premolars and found 101 Kgf as the mean in a compression test; however, they did not mention the age of the teeth. In our experiments, the mean of compressive loading on the teeth of young and elderly was 103.2 kgf.…”

“…Regarding the mean compressive loading applied to first maxillary premolars, the present study found 77.5 Kgf and 128.9 Kgf for young and old, respectively. Minto et al 29 analysed intact maxillary premolars and found 101 Kgf as the mean in a compression test; however, they did not mention the age of the teeth. In our experiments, the mean of compressive loading on the teeth of young and elderly was 103.2 kgf.…”