Journal of Dental Medicine

Peripheral giant cell granuloma (P.G.C.G) is an exophytic lesion with an approximate size of 0.5-1.5 mm. It usually occurs on gingival and alveolar ridge of mandible particularly in molar and premolar region. The relation of serum calcium (Ca), Phosphor (P), and alkaline phosphatase (Alk) levels to P.G.C.G is yet controversial. In this descriptive study, 33 patients with P.G.C.G were chosen and serum Ca, P, and Alk levels compared with the normal range. In all patients the level of Ca was in the normal range. Phosphor (P) was in the normal range in all patients over 17 years old and 80% under 17 years. The level of ALK in 75.8 percent of the patients over 17 years and 90% under 17 years was in the normal range. In conclusion, no relationship was found between serum changes and P.G.C.G. It means P.G.C.G can be compeletly independent lesions from serum changes.

Background and Aim: Geographic tongue (GT) is a relatively common lesion which is usually asymptomatic and found during routine examinations. Lesions may be single or multiple and frequently are confined to the dorsal surface and lateral borders of the tongue. Although the cause is unknown, zinc deficiency has been suggested as a possible etiologic factor. The purpose of the present study was to determine the therapeutic effect of zinc sulfate in patients with geographic tongue.

Materials and Methods: This study was a randomized double blind clinical trial performed on 40 cases. 20 patients in experimental group were given zinc sulfate and 20 patients in control group took placebo. Slides were taken at the first day and healing was recorded after 10 days. Data were analyzed using chi-square test with P<0.05 as the limit of significance.

Results: In 16 cases of the experimental group and in 3 cases of the control group signs of healing were observed.

Conclusion: Regarding the role of zinc in epithelial tissues health and development of filliform papillas and in spite of the positive effect of zinc sulfate in treatment of geographic tongue, further investigations concerning its effects on other mucosal conditions are recommended.

Background and Aim: Nowadays, esthetic dentistry has become an important part of modern dentistry. Bleaching is considered as a conservative, safe and effective way for treatment of discolored teeth. Although bleaching is commonly used on anterior teeth, the bleaching gel may come into contact with patient's former amalgam restorations and result in corrosive effects, dissolution of amalgam phases and increasing release of mercury. Mercury released from dental amalgam during mouthguard bleaching can be absorbed and increase the total mercury body burden. The aim of this study was to determine the amount of mercury released from Iranian and foreign brands of amalgams with spherical and admixed particles, polished and unpolished, after 16%carbamide peroxide gel application.

Materials and Methods: This experimental in vitro study was performed on 256 Iranian and foreign amalgam samples with spherical and admixed particles. The provided samples were put in distilled water and classified according to the type of amalgam, shape of particles and quality of surface polishing. The test samples were placed in Nite White 16% carbamid peroxide gel and control samples were put in phosphate buffer (Ph=6.5) for 14 and 28 hours. The amount of released mercury was calculated using AVA-440 Mercury Analysis System (Thermo Jarrell Ash model SH/229) with cold-vapor atomic absorption. Data were analyzed using t-test, four way and three way ANOVA tests with P<0.05 as the level of significance.

Results: 16% Nite White carbamide peroxide gel caused a significant increase in amount of mercury released from amalgams in all groups (P<0.05). Mercury release from Iranian amalgam was higher than that from the foreign brands (P<0.05). There was no significant difference in mercury released from spherical and admixed amalgams (P>0.05). The amount of mercury released from Iranian and foreign amalgams was time dependent (P<0.05). Furthermore, the amount of mercury released from unpolished amalgams was higher than polished ones (P<0.05).

Conclusion: The present study indicated that exposure of amalgam to 16% Nite White carbamide peroxide  gel causes a significant increase in mercury release from the amalgam which is significantly influenced by the brand, exposure time, and surface polishing.

Background and Aim: Contaminated dental handpieces have the potential to transfer infection to patients. New generation of autoclavable turbines have to some extent overcome the problem however, in clinic sometimes it is necessary to use chemical to disinfect handpieces. The aim of this study was to determine the antimicrobial effect of some routinely used disinfectant solutions on dental contaminated handpieces.

Materials and Methods: In this experimental study 35 turbines were sterilized. The turbines' heads were inserted into microbial suspension containing staphylococcus, pseudomonas and candida and then exposed to the disinfectant solutions. Inoculations into culture medium were made at different intervals. All medium was incubated for 24 hours at 37^oC followed by spectrophotometer inspection for detection of microbial growth. Serial dilutions of disinfectant agents were used to determine the highest dilution in which there was no microbial growth. Kruskal wallis test was used for statistical analysis and p<0.05 was considered as the level significance.

Results: Ethanol had antimicrobial effect on all of the tested microorganisms at dilution of 1:4. Betadine at dilution of 1:64 caused inhibition of all of the microbes except pseudomonas. Micro 10 had antimicrobial effect up to dilution of 1:256 but could not inhibit microbial growth at higher dilution. Sodium hypochlorite inhibited growth of the three microoganisms up to dilution of 1:1024.

Conclusion: Based of on the results of this study sodium hypochlorite was found to be the most effective antimicrobial agent among those used in this study, inhibiting microbial growth at the highest dilution.