Journal of Dental Medicine

There are two types of high-copper dental amalgams produced in Iran Cinalloy (lathe-cut particles) and Cinalux (spherical particles). Tarnish is one of the disadvantages of dental amalgam, which precedes corrosion, and in fact it means real destruction of restorative materials. The purpose of this study was to compare the extent of tarnish in Cinalux and Cinalloy amalgams. 32 patients, with at least two carious or poorly restored teeth were selected. Then, each tooth was restored with one of these two types of dental amalgams. The restorations were polished after 24 hours and patients were followed up after 9 months. The restorations were categorized in four groups of no change, one plus (1-30%), two plus (30-60%) and three plus (more than 60%) according to the level of discoloration. The results showed that the level of tarnish in Cinalux group was significantly less than Cinalloy group. The mean of tarnish for Cinalloy and Cinalux was 2.09±0.59 and 1.72±0.68 respectively. In addition, statistical analysis showed that there was no significant relationship between tarnish and Oral hygiene, smoking, operator or type and place of restoration.

Statement of Problem: Eugenol is the most important chemical compound of the clove tree (Eugenia aryophylata) extract. That is widely used in dentistry as a bactericidal and pain relieving agent.

Aim: The aim of the current study was to evaluate the antinociceptive effect of local and systemic administration of eugenol by formalin test in rats.
Materials and Methods: In this research, 56 male Wistar rats, weighing 230±20 g were divided into seven groups (n=8). Ten minutes before formalin test, different doses of eugenol (12.5,25,50 mg /in groups 2,3,4 respectively) were injected to the right hind paw of the rats subcutaneously. In- group 5 eugnol (50 mg) was. injected to the contralateral hind paw. In group 6 eugenol (100 mg/ kg) and control group (group 7), equal volume of norma! saline was injected intraperitonealy . The minutes 0-5 and 16-60 were considered as acute and chronic phases of pain in the formalin test, respectively. Data were statistically analyzed by ANOVA and Tukey's tests.
Results: The results showed that local injection of eugenol to the same paw receiving formalin caused a decrease of nociception in both acute and chronic phases of formalin test (PO.005). However, in the group that eugenol (50mg/ kg) was injected to the contralateral paw, no significant differences were observed in the pain score in comparison with the control group. Intraperitoneal injection of eugenol (lOOmg/kg) did not reduce the nociception in the acute phase, but it caused a significant decrease of nociception in tonic phase (PO.00I).
Conclusion: It was concluded that eugenol, as a local anesthetic drug not only inhibits nociceptive impulse conduction on the peripheral pain fibers, but also centrally reduce chronic pain.