مجله دندانپزشکی دانشگاه علوم پزشکی تهران
سال بیست و هفتم شماره 4 (پیاپی 81، زمستان 1393)

The main cause of erosion is acid exposure. Side effects of erosion necessitate therapeutic agents’ uses. The aim of this study was to investigate the effects of nano- hydroxy apatite in tooth remineralization following exposure to soft beer. This in vitro experimental study was conducted on 18 human impacted third molars that had been surgically extracted. The microhardness of specimens was measured. Then teeth were exposed to soft beer and their secondary microhardness was measured. The teeth were divided into 2 groups (water and nano-hydroxy apatite solution) and were placed on 9 orthodontics appliances and delivered to 9 volunteers. These volunteers placed the tooth on one side in water for 5 minutes and the tooth in opposite side in nano-hydroxyapatite solution. This application was repeated 6 times a day for 10 days. The microhardness of teeth was measured again. Data were analyzed using Paired T-test. The tooth enamel microhardness reduced after exposure to soft beer significantly (P=0. 04). The microhardness of 9 teeth after being in water showed significant changes (P=0. 012). The microhardness of 9 teeth significantly changed after exposure to nano -hydroxyapatite solution (P=0. 001). Based on the results of this study، 10% solution of nano- hydroxy appatite could restore the erosive lesions.

The most effective preventing tooth decay method is fluoride compounds applications. Some studies suggested that APF gels caused changes on the superficial physical properties of composite. Therefore, the purpose of this study was to evaluate the marginal microleakage of class V composite restorations before and after AFP gel application. The class V cavities in buccal surfaces of 45 molar teeth were made in such a way that occlusal margin was placed in enamel and cervical margin in cement. In group 1, at first fluoride-therapy and then cavity preparation and restoration by composite resin was done. In group 2, at first the class V cavities were prepared and restored, then fluoride-therapy was carried out. In group 3, cavities were prepared and restored with no fluoride-therapy. The dye penetration rate in occlusal and cervical margins was examined by stereomicroscope. Data were statistically analyzed using Kruskal-Wallis and Mann-Whitney test. There was no statistically significant difference between groups (P=0.975). Fluoride-therapy using AFP gel before and after class V composite restorations, had no significant effect on the microleakage of dentin and enamel margins.

Postoperativee endodontic pain is an outstanding problem for dental patients. Therefore, a successful management of endodontic pain has become as one of the main dental objectives. The aim of the present study was to compare the postoperative endodontic pain in patients under general anesthesia versus local anesthesia. For conducting this clinical trial study, 50 patients having mandibular molars candidate for root canal therapy were selected. Twenty-five patients treated under general anesthesia because of their fear, anxiety or gag reflex. Other 25 patients treated under local anesthesia. All teeth were prepared using engine-driven rotary system in a crown-down technique and filled using lateral condensation technique. Heft- parker visual analog scale was used to measure the degree of pain at 6, 12, 24, and 48 hours after the treatment. Mann-Whitney, Chi-square, and T-tests were used to compare the intensity of postoperative pain between the groups. The mean intensity of postoperative pain in local and general anesthesia groups at 6, 12 and 24 hours had statistically significant difference (P<0.05). Postoperative pain in patients who treated under general anesthesia was significantly less than the patients who treated under local anesthesia.

Dental caries is one of the most common infectious diseases which could be prevented in various ways. The aim of the present study was to evaluate the effect of a toothpaste containing different concentrations of nano-hydroxyapatite on the remineralization of incipient caries. 9 sound first premolar teeth of maxilla and mandible were sectioned to four pieces. 6 specimens were stored in distilled water as control group. The remaining 30 specimens were demineralized for 72 hours and then their microhardness was measured. 0, 0.5, 1, 2 and 5% wt nano-hydroxyapatite were added to the solution of distilled water and toothpaste. Specimens were divided into 5 groups (N=6) and after demineralization, each group were randomly immersed in the above-mentioned solutions for 15 minutes. Next, specimens were kept in artificial saliva for 1 hour followed by immersion in the related remineralizing solution for another 15 minutes. This procedure was repeated for 5 days. Finally, the microhardness of the teeth was measured. Data were analyzed using repeated measures analysis of variance (ANOVA). The microhardness of demineralized teeth was increased following exposure to different concentrations of nano-hydroxyapatite, but this increase was not statistically significant (P=0.62). Nano-hydroxy apatite can enhance remineralization and increase the tooth microhardness although this increase was not significant.

Hepatitis B is an important infection route in dentistry requiring different disinfectants to prevent its transmission. The aim of this study was to compare the effects of chemical disinfectants (FD366, ISORAPID and 5% sodium hypochlorite 2/100) to remove Hepatitis B infections from the dental surfaces. In this experimental laboratory trial, serum of 10 HBV patients was poured into microtubes, FD366, ISORAPID and hypochlorite disinfectants were added to them. PCR experiments with viral diagnostic kits were used to diagnose the virus genome. Real time PCR was used to evaluate after incubation with the disinfectants. The reductions occurred in the viral load of Hepatitis B were statistically analyzed using Kruskal-wallis and Mann-Whitney U tests. No significant antiviral efficacy was noted following the application of FD366 and ISORAPID disinfectants (P=0/07). However, hypochlorite showed the most efficacy to disinfect Hepatitis B and a significant difference was found among them (P<0.0001). Under the study limitations, FD366 and ISORAPID disinfectants did not show adequate efficacy to remove Hepatitis B virus. Hypochlorite was the most effective disinfectant.

In case of nonsurgical endodontic re-treatment or replacing a restoration, one of the best methods for removing post from the canal is using an ultrasonic vibration. The aim of this study was to evaluate the effect of ultrasonic vibration time on the retention of post luted with zinc phosphate or glass ionmer cements. 96 sound extracted lower premolars were selected. The coronal section of specimen was removed and the roots were endodontically treated. A 9-mm post space was prepared in each specimens and a stainless steel Parapost XP was cemented into the post space. Half of the specimens were cemented with the Zinc phosphate cement and the other by g lass ionomer cement. After 7 days of storage, both groups were equally divided into 4 subgroups of 12 teeth. Control group did not receive any treatment. The other subgroups subjected to ultrasonic vibration for 4, 8 or 12 minutes. The retention of all specimens was evaluated and data were analyzed using ANOVA and Tukey tests. In control (no ultrasonic) group and 4 minute ultrasonic group, the retention of posts luted with Zinc phosphate cement were not significantly differen t from those luted with g lass ionomer cement. (P=0.372). On the other hand, applying of ultrasonic vibration for 8 and 12 minutes in zinc phosphate and 12 minutes in g lass ionomer caused a significant reduction in the retention of posts (P=0.01). Although, the initial retention of two cements was not different, the ultrasonic vibration had more catastrophic effect on zinc phosphate in comparison to glass ionomer.

In the panoramic images, palatoglossal space error develops when the patient is unable to put the tongue against the mouth roof. In the case of this error, the radiographic diagnosis of the area is made with some difficulties or ever the image may lose its diagnostic ability. The aim of the present study was to investigate the relationship between the palatoglossal space error of the panoramic images and skeletal relationship. In this descriptive cross-sectional trial, 494 panoramic images were selected at the orthodontic department of Tehran dental school archive and the existence of the palatoglossal space was determined. The palatoglossal space error was statistically analyzed using chi-square test regarding the patients’ gender, age and skeletal relationships. Of total panoramic images, 346 (70.0%) cases showed palatoglossal space error while 148 (30.0%) images were free from this error. Furthermore, 74.1% of male images and 66.9% of female images showed palatoglossal space error. In Cl I (1˂ANB≤3), Cl II and Cl III patients; 65.6%, 73.1% and 67.4% of the images demonstrated the error, respectively. The incidence of palatoglossal space error in 5-14 and 15 years old age or higher patients were 72.2% and 58.8%, respectively. It was concluded that n o significant difference w as noted between the incidences of the palatoglossal space error regarding the patients’ gender or their skeletal relationships. T he error frequency was significantly decreased with age.

The purpose of the present study was to review the studies regarding serological and salivary oxidant / antioxidant status in patients with recurrent aphthous stomatitis (RAS). The literature was searched using key words RAS, Antioxidants, Saliva, Hematinic (s) and Hematinic Acid in the last 10 years, particularly the recent 3 years (2010-2013). At total of 37 clinical trials, 18 case-control articles were selected and evaluated; fulfilling the requirements as the RAS patients having at least 3 oral aphthous attack per year. The exclusion criteria included systemic as well as periodontal diseases, iron deficiency associated anemia, medication usage and smoking. Almost all lipid-peroxidation studies in serum and saliva were manifested by an increase of malondialdehyde (MDA) concentration in RAS patients compared with controls. This would indicate the role of reactive oxygen species (ROS) in the etiology of the disease. Serum trace elements (Zn, Se) were reduced and Cu was increased in RAS patients in comparison with control individuals. A decreased serum superoxide dismutase (SOD) and an increased salivary SOD were observed in all RAS patients. Catalase (CAT) and uric acid (UA) analyses were non-inclusive. Levels of paraoxonase and arylesterase as well as antioxidant vitamins (A, E, C) were lower in RAS patients than that of controls.

Temporomandibular joint disorders are common problems among patients referring to dental schools and clinics. However appropriate treatment modalities are performed for the TMD patients in dental school, the results and success rate of these treatments are not studied distinctly. The aims of this study was to determine the treatment performed for temporomandibular patients at the TMJ department of Tehran University dental school in 2010-11. In a descriptive cross-sectional trial, 85 TMD patients treated at the TMJ department of Tehran University dental school were examined at least 3 months after the treatments. The patients demographic data, TMD signs and symptoms and the improvements occurred in TMD disorder were determined (complete, partial and no improvement). The patients satisfaction regarding the treatment results were investigated and data were analyzed regarding the presence of different TMD signs and symptoms before and after the treatment using Mann-Whitney U test. TMJ pain (35 cases, 42.2%), click (33 cases, 39.8%) and muscle tenderness (26 cases, 31.3%) were the most prevalent obtained signs and symptoms. The mean age of the patients were 32.3 years old while females were the predominant group (72 cases vs.11 one). 44 individuals (53.0%) were treated by splint, 11 ones (13.3%) with anterior repositioning splint and 17 individuals (92.5%) were managed by physiotherapy plus splint. 65 patients (87.3%) were satisfied with the results and 16 ones (19.3%) were not. After the treatment, patients with TMJ pain (P<0.001) and muscle tenderness (P<0.001) showed significantly lower satisfaction than that of patients with no signs. No other significant differences were noted between patients satisfaction regarding the presence of TMD signs and symptoms (P>0.05). The results showed that the treatments presented for the TMD patients at Tehran University dental school were successful and most patients received satisfactory treatment.

Oral health is an important issue in public health with a great impact on individuals’ general health status. A good access to oral healthcare services and a good knowledge of it play a key role in the oral disease prevention. A better health attitude and practice require a better knowledge. The aims of this study was to evaluate the oral health knowledge among the International students branch (Kish) of Shiraz University of Medical Sciences in 2011-12. 159 pre-clinical students in medicine (54 students), dentistry (69 students) and pharmacy (36 students) participated in this research. A standard questionnaire was used as the main tool of research to evaluate the attitude and knowledge of students about the oral health. Data were analyzed using Chi-square test. According to the results, dental students had the best level of knowledge and pharmacy students had a better knowledge level compared to the medical students. The results also showed a significant relationship between students’ oral health knowledge and their field and duration of study and the place of their secondary school (P<0.05), while no significant relationship was observed between their oral health knowledge and their gender or their parents’ educational level (P>0.05). The results showed that the students at the International Branch of Shiraz University of Medical Sciences had a relatively good knowledge of oral health. Students’ knowledge level can be improved by providing students with educational materials, organized workshops and seminars.

Dental environment is a stressful place for children. In many cases, parents transmit their anxiety to their children in the first dental visit. Mothers as the closest person to the children may have important influence on their children’s behavior in dentistry. The purpose of this study was to evaluate the effectiveness of an educational pamphlet for mothers on children’s behavior in the first dental visit. This study was conducted on 238 mothers who had 3-7 years old children undergoing dental treatment for the first time. The participants were divided into interventional and control group randomly. Behavior of children was assessed by questionnaire according to 4 point scale of Frankle. The questionnaire contained 5 parts: separation of child from the mother, entering the dental room, opening the mouth, communicating with dentist, getting the prize. Data were analyzed using Chi-square test. The educational pamphlet was effective on the separation of child from the mother, the cooperation of children in interventional group was better than the control group (P=0.006). In interventional group 96.2% of and in the control group 90.8% of children had good and very good behavior but the difference was not significant (P=0.11). Although the educational pamphlet was effective on the separation of child from mother. No significant difference in behavior of 3-7 year-old children between interventional and control group was found.

The importance of quality in medical education makes the need for better standards in educational systems in the center of interest as the basis for certification. Standards needed to be evaluated by program administrators before the implementation phase. The purpose of this study was to evaluate the general dentistry standards program in Islamic republic of Iran from dental schools view point. This descriptive study was performed during the year 2011 and 2012. A list of 16 faculties was introduced by the dental secretariat of the Ministry of Health and Medical Education. A check list was conducted based on the basic standards of undergraduate dental program that consisted of the importance and feasibility of each standard. The checklist was evaluated by sixteen dental schools representatives and asked their faculty members and reported back to the dental secretariat of the Ministry of Health. Results were reported in descriptive statistics manner. Data were collected from 14 dental schools. (Response rate=87%). All of the criteria were essential with more than 85% agreement of the faculties. There were more than 70% of criteria that were not feasible in less than one year. The dental standard program was widely accepted by the faculties over the country. However, it seemed that by the faculties it would fail if used as accreditation base line.