مجله دندانپزشکی دانشگاه علوم پزشکی تهران
سال سی و دوم شماره 4 (پیاپی 101، زمستان 1398)

Various methods to induce anesthesia have been investigated in situations where the primary inferior alveolar nerve block (IANB) injections fail. The aim of this study was to compare the effect of synergic effects of anesthetic injection of prilocaine supplemental with that of lidocaine anesthesia in teeth with irreversible pulpitis.

This study was a parallel-controlled clinical trial on 58 patients with one mandibular molar tooth having irreversible pulpitis. The first anesthesia was injected with an inferior alveolar block with 2% lidocaine anesthesia. Patients who failed pulpal anesthesia were randomly divided into two groups; case and control groups. In the case group, IANB was injected with 3% prilocaine, and in the control group with 2% lidocaine anesthesia. Anesthesia after the second injection was evaluated by three methods of numerical evaluation of the patient's response to Electric Pulp Tester (EPT), the severity of the patient's response to the cold test, and the extent of pain during the onset of access cavity latency on the Visual Analog Scale (VAS). Statistical analysis was performed using T-test and Mann-Whitney tests.

There was no significant difference between the two groups in terms of depth of anesthesia (P>0.05).

The results of this study showed that there was no difference between 2% lidocaine and 3% prilocaine in the depth of supplemental IANB anesthesia after failure of first IANB in mandibular molar teeth with irreversible pulpitis.

Oral squamous cell carcinoma (OSCC) is one of the most prevalent oral cancers with increased risk in individuals younger than 40 years especially in developed countries. There are many evidences that people who have plenty of fruits and vegetables in their diets tend to have lower risk of cancer. In this study, we evaluated the anticancer effect of four medicinal plants of Otostegia Persica, Otostegia Michauxii, Otostegia Aucheri, and Hibiscus Sabdariffa on OSCC cell lines.

In this study, methanolic & dichloromethane extracts of the above medicinal plants were used in order to evaluate their effect on oral squamous cell carcinoma cell line in different concentrations and after 24 , 48 and 72 hrs by MTT assay test. Finally, the appropriate concentration for repeating the test were chosen.

In this study, the mean amounts of IC50 for O. persica and O. Aucheri were less than the two other herbs and the least and most amount of IC50 were related to the dicloromethanolic extract of O. persica after 72 hrs and the water extract of H. sabdariffa after 24 hrs, respectively.

It was concluded that all of the plants evaluated especially O.Persica and O.Aucheri had anticancer properties and dichloromethalonic extracts of these plant were more effective than that of methanolic extract.

One of the most important challenges for dentists is providing a crown with appropriate marginal fit and gap. The 135-degree tooth preparation found to have some advantages such as technical ease and appropriate finish line record. Despite the advantages of 135-degree tooth preparation, scant research has been done in this area. Therefore, the aim of this study was to compare 135-degree and deep chamfer tooth preparation on the marginal fit and marginal gap of posterior metal-ceramic crowns.

Deep chamfer and 135-degree tooth preparation were performed on the two first mandibular molars with healthy coronal tissue and similar size. Impression was taken from each tooth and 30 crowns were made on each die. The sample plastered with fit checkers were pressed under the force of 40 N for 3 min in a universal testing machine. They were measured and recorded under a loop with 40x power in three points on each aspect. Data were analyzed by Wilcoxon and Kolmogorov-Smirnov tests using SPSS version 24.

The mean marginal fit values in deep chamfer and 135-degree were 48.5417µm and 55.3333 µm, respectively with no statistically significant difference (P>0.05). While the mean marginal gap in deep chamfer (2.4833 µm) was significantly higher (P<0.05) than 135-degree (1.0083).

It can be concluded that the marginal gap by 135-degree’s tooth preparation was lower than that of deep chamfer in metal-ceramic crowns. However, no significant difference in the marginal fit between the deep chamfer and 135-degree tooth preparation was found.

Nasal obstruction is a common condition among children, in which delaying treatment can stabilize its negative effects on dentoalveolar structures during adulthood. In this study we aimed to investigate the effect of total nasal obstruction on the craniofacial structures of rabbits.

In this animal study, total numbers of 44 rabbits with high genetic proximity were selected. Several metal implants were inserted in the anatomic landmarks of their skulls and then underwent three different types of x-ray exposure (lateral, posterior-anterior and occlusal views). Half of them underwent surgically assisted total nasal obstruction, and the other half were considered as control group. All rabbits were kept in the same environment up to maturation period. Then, they underwent the same x-ray exposures. The primary and final radiographs were traced and various linear and angular were compared between them.

The anterior facial height (P=0.01), maxillary depth (P=0.005), articular angle (P=0.005), maxillary and mandibular plan angle were significantly more in the rabbits with total nasal obstruction. However, the interdental width (P=0.005), maxillary perimeter (P=0.005), nasopharyngeal width (P=0.01) and maxillary and mandibular width were significantly less in them. The skull base length (P=0.30), gonial angle (P=0.40), and maxillary length (P=0.10) were not significantly different between the two groups.

Total nasal obstruction had various impacts on the craniofacial structures.

Dental caries is a multifactorial and common disease that leads to a decrease in the quality of life of individuals. The aim of this study was to determine the relationship between serum vitamin D and dental caries in the third year-to-last year students of dental school of Tehran University of Medical Sciences.

This descriptive cross-sectional study was conducted on 123 dental students. Demographic and health information were completed through a checklist. The level of vitamin D in individuals was measured by blood sampling. We recorded caries by ICDAS (international caries detection and assessment system) in two levels of D(1-6)MFT (total of decayed, filled and missing tooth) and D(3-6)MFT (total of progressive decayed, filled and missing tooth). Data analysis was done by the SPSS package version 25 using statistical tests of correlation and regression.

The results showed that the correlation coefficient between vitamin D and caries index D(1-6)MFT was -0.89 with a P-value of 0.3328 which was not statistically significant. Based on the backward logistic regression, there was a positive significant statistical association between the D(3-6)MFT with vitamin D deficiency (P<0.001), weight (P=0.012), dental visit (P=0.023) and frequency of sweet snack consumption (P=0.03). In addition a significant and inverse statistical association was reported between the D(3-6)MFT and milk consumption (P=0.026).

Among dentistry students, no relation between vitamin D deficiency and early stages of decay was seen, however this relation was statistically significant in regard with progressive dental caries.

Considering the role of primary teeth in children's dental health and the importance of parental role on children dental health the purpose of this study was to determine the knowledge and practice of parents of 3-9 year-old children regarding to maintaining primary teeth.

This cross-sectional descriptive-analytical study was conducted on the parents referring to Ahwaz dental school in 2017. Using a questionnaire, the participants' demographic characteristics, knowledge and performance regarding maintaining of the primary molars were collected. The percentage of correct responses was considered as the level of knowledge and performance. Analysis of K-square and Spearman and Pearson correlation coefficient and T-test were employed to determine the relationship between the participants' knowledge and performance and their demographic variables. The significance level was P<0.05.

176 parents completed the questionnaire. The mean parental knowledge score was 57.42±7.45 (range 15-75), and the mean practice score was, 9.42±1.86 (range 4-12). No relationship was found between the parents’ age, sex, knowledge, and performance. The knowledge of parents who had a history of referral to the dentist, fewer children (rs=0.428), higher education (rs=0.490) and higher income (r=0.226) was significantly better (P<0.001). Also practice increases with higher awareness of parents (r=0.549) (P<0.001). The parents’ practice was significantly related to the history of referral to the dentist, and having fewer children (rs=0.320), higher education (rs=0.369), and higher income (r=0.253) (P<0.01).

The findings of this study showed that the knowledge and practice of the parents about primary teeth were moderate. Regarding the important role of primary teeth in children's health, increasing the parents’ knowledge on the maintenance of primary teeth is essential.

Advances of genetic science in genomic techniques have led introducing new diagnostic systems to study the diseases or treatment efficacies. In this science, which named “Personalized Medicine”, human genetic structure is used for evaluation of the diagnosis, treatment, and prevention of disease. Regarding the limited number of studies regarding this issue in Oral & Maxillofacial diseases, this study was aimed to evaluate the benefits and challenges of this new area (Personalized Medicine) in dental treatments.

In this study, complete evaluation of abilities and challenges in order to apply the “Personalized Dentistry” in Dental treatments, and also its effect on oral health indexes were done. All the existing related articles were searched with the relevant key words in the scientific data bases of PubMed, Google Scholar, Medline, Scopus, SID and Magiran. Based on the inclusion and exclusion criteria, 5 articles were selected, assessed and summarized.

In the evaluated articles, the benefits of “Personalized Dentistry” in dental treatments as targeted and specialized treatment could result in lower time, energy and cost. In addition, its disadvantage as unknown biologic effective factors and also, the cross effects of some of the above items on each other and the treatment procedures were mentioned.

Regarding the specialized sciences and diagnostic tools for oral & maxillofacial disease, the benefits of “Personalized Dentistry” application can be increased for special treatments of patients. Also, it could reduce the side effects of conventional therapies and thus, could be introduced as an effective step for better dental treatments.

All metal components of orthodontic appliances are somewhat corroded in the oral environment due to some changes in chemical, mechanical, thermal, microbiological and enzymatic factors which facilitates ion release. Ionic release can result in a discoloration of the surrounding soft tissue or allergic reactions in sensitive patients or even local pain in the area. In general, ions can cause toxic and biological side effects if their values reach the threshold, so the release of ions from the metal components of orthodontic appliances is important to us. The aim of this review article to determine the rate of orthodontic appliances ion release in different solutions.

A review of the literature was carried out in Pubmed, Google Scholare and Web of science database using selected key words (Saliva/ Titanium/Normal Saline/ Ion release Orthodontic appliance/Mouth wash/ Nickel/ Chromium). These searches were limited to the articles published from 2005 to 2018. According to the inclusion and exclusion criteria, 25 articles were obtained.

Because of conflicts in the reported results, it was necessary to synchronize the measurement methods and also to use artificial saliva medium with normal pH as a control to achieve better systematic comparison.

There was significant differences in the ion release between mouthwashes. In all studies, the effect of pH and acidity has been shown to increase the release of these ions. In addition, stainless steel (SS) instruments had the least biocompatibility among all types of alloys evaluated.