Journal of Dental Medicine

Background and Aims: Residual ridge resorption is an unpredictable, unavoidable and time-dependent process which occurs in denture-wearing patients especially those who use mandibular dentures. This process causes more problems in mandible because of its less support, tongue forces and more resorption. Inserting implants in many of these patients requires bone grafts. Overdentures are also more expensive. Denture adhesives are the last option to improve retention and masticatory function in denture-wearers with severe resorption of alveolar ridge. Nowadays only a few denture adhesives are used in Iran and there is not much information about their standard features including, pH, bond strength and washability. The objective of this study was to examine and compare the mentioned characteristics of four denture adhesives (Professional, Corega, Fittydent and Fixodent) and to introduce the most suitable denture adhesive for clinical use.

Materials and Methods: All the methodologies of ISO 10873:2010 were applied. To measure the pH value, 1±0.1g of each denture adhesive was diluted with 5g of propylene glycol and mixed with water. Using pH meter, pH of each group was measured separately for 4 times (n=4) and results were recorded. For the washability test, 4 dentures were fabricated (n=4) and each group of denture adhesives was placed on a denture according to manufacture instructions. For simulating mouth environment specimens were placed in water at 37±2 ̊C bath for 1 hour and then washed with a plastic brush. Specimens were examined for any residual adhesive and the results were recorded. For bond strength test, a sample holder was gently filled with denture adhesives and was attached to the holding arm of bond strength testing device (Santam, STM 20, Iran). Specimens were placed in 300ml water bath at 37±2 ̊C for 10 minutes, and then shaken to be dried and placed in the bond strength testing device. 10N force with 5mm/min rate was applied to the specimen. The force was maintained for 30s and then device arm was pulled back and the highest number was recorded with computer software (Santam Machine Controller v4.19, Iran). The test performed 8 times (n=8) for each adhesive and 8 results were recorded. Data were analyzed using ANOVA test for comparing the bond strength with a significant level fixed
at 0.05.

Results: Professional and Corega adhesives had more neutral pH than that of Fittydent and Fixodent which were more acidic. Washability test showed no remaining mass of any adhesive and there was not any statistically significant difference between groups (P>0.05). Fittydent and Corega adhesives showed higher bond strength than that of Professional and Fixodent and this difference was statistically significant (P<0.05).

Conclusion: Professional and Corega adhesives had less acidity. Thus they cause less harmful effects on the oral mucosa than that of Fittydent and Fixodent and should be indicated in patients with little-tolerant oral mucousa such as diabetous, iron-deficiency anemia and hypertention. All the groups had acceptable washability. Fittydent and Corega had higher bond strength than that of Professional and Fixodent. Therefore in complete-denture-wearers who require more retention as a result of severe ridge resorption, macrotruma, and maladaptiivity, Fittydent and Corega seems to be more acceptable.

Background and Aims: The dentist's attire and appearance affects his/her relationships with the patients. It is also essential to sync the professional attire in dentistry with the habits and Islamic culture of Islamic Republic of Iran, meet the patients' desires, and pay attention to the infection-control-requirements as well.The objective of the present study was to determine the patients' viewpoints about the professional appearance of the dentists at Tehran University of Medical Sciences, Dental School in 1395-96.
Materials and Methods: In this descriptive cross-sectional study, 103 patients (54 females and 49 males) were studied. (=α0.05 and standard variation=4.5). The questionnaire were included color photographies of a female dentist and a male dentist dressed in different attires. The patients were asked to select the cleanest, and the most trustable, competent, and experienced dentist according to the 4 different attires. The frequencies and percentages of the participants’ answers to the questionaire were descriptively reported.
Results: All patients preferred dentists to use white coat during their treatment. For the male dentists, most patients (45.6%) favored simple hair model. For the female dentists, most patients (35.9%) considered veil as the more acceptable Hejaband, and 54.4% of them preferred light makeup.
Conclusion: All patients preferred their dentists to dress in the professional attire with a white coat. They believed that wearing formal-professional-dressing by the dentists may show them look cleaner, and more trustable, more competent, and experienced.

Background and Aims: Most children get a lot of anxiety while they visit a dentist. The most important factor in the child's fear at the beginning of treatment is the syringe and needle. Ways to cope with this anxiety include behavioural control techniques such as mental regeneration, distraction, and induction. The purpose of this study was to compare the pain and anxiety in children when using a syringe and toy- shape syringe needle. This study was the first study that used a toy-shape needle cover.
Materials and Methods: This clinical trial study was conducted on 20 children age from 5 to 8 years. More than half of them were anxious with Cfss-Ds (Dental Subscale of the Children's Fear Survey Schedule) and FIS
(Facial Image Scale) anxiety diagnostic tests, and the rest of them were not anxious. Patients were randomly divided into two groups. The first group received local anesthesia with conventional syringe and the second group, by syringe with toy shape needle cover. Following, the first group received local anesthesia by syringe with toy shape needle cover, and the second group, by a conventional syringe. Heart rate measuring and pain evaluating test was performed. Analysis of heart rate and anxiety data was performed by non-parametric wilcoxonsianed Ranks T-test (P-value was considered significant at 0.001).
Results: The mean amount of pain measured after using a syringe with a toy shape needle cover and using conventional syringe had a significant difference of 5.20% between the two groups. The pain was reduced in children who received local anesthesia by syringe with toy shape needle cover (P<0.001).
Conclusion: The physical appearance of the injection device plays an important role in reducing the anxiety and pain of injection in the children.

Background and Aims: Recently, the addition of nanoparticles into the restorative materials and tooth preparation by laser for improving the bond strength have been concidered by researchers. The aim of this study was to investigate the shear bond strength of the bioactive glass ionomer containing titanium particles and a conventional glass ionomer with two surface treatments by Er-YAG laser and conventional methods.
Materials and Methods: In this in-vitro study, 64 sound extracted premolars were collected. For conventional method, the specimens were prepared in such a way that dentin surfaces with a depth of 0.5 millimeter created at distance of 2 mm from the joint of CEJ at the root or crown.  In the laser group, after preparing the teeth, the surface area was prepared by Er-YAG laser. Then, in the middle part of the buccal surface, a cylindrical mold with dimensions of 3.5 mm in diameter and 4 mm in height was placed and for each group was filled with its own glass ionomers. The  specimens  were divided into 8 groups by simple random sampling (n=8): A (laser, conventional glass ionomer, coronal dentin)/ B (laser, glass ionomer containing titanium nanoparticle, coronal dentin)/C (conventional, conventional glass ionomer, coronal dentin)/ D (conventional, glass ionomer containing titanium nanoparticle, coronal dentin)/ E (laser, conventional glass ionomer, root dentin)/ F (laser, glass ionomer containing titanium nanoparticle, root dentin)/ G (conventional, conventional glass ionomer, root dentin)/ H (conventional, glass ionomer containing titanium nanoparticle, coronal dentin). Finally, the shear bong strength by a universal testing machine was measured at a cross-head speed of 1 mm/min. For data analysis, Two-way ANOVA test was used to evaluate the effect of each variable and their interaction on the shear bond strength and Tukey test was used to compare the two groups.
Results: There was significant difference only between groups B with C (P=0.002), E (P=0.007), G (P=0.001) and H (P=0.01). The highest bond strength was found for group B (laser, glass ionomer containing titanium nanoparticle, coronal dentin) and the lowest bond strength for group G (conventional, conventional glass ionomer, root dentin).
Conclusion: All three factors of Er-YAG laser, glass ionomer containing titanium nanoparticle and coronal dentin had a positive effect on the improvement of the bond strength.