Journal of Dental Medicine

Background and Aims: 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.
Materials and Methods: 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.
Results: 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).
Conclusion: 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.

Background and Aims: Information collection about the malocclusion and oral health in blind children is essential to plan for their education in schools. Therefore, this study aimed to evaluate the status of malocclusion and oral health among blind children and teenagers in Mazandaran, Iran.
Materials and Methods: The population of this included 150 blind children and teenagers aged from 10 to 18 years who were referred to the public and private centers cities including Sari, Babol, Freydoonkenar, and Babolsar in Mazandaran, Iran in 2019. Information on maxillary occlusion status, oral hygiene index, and DMFT index was extracted through clinical examination. Data were analyzed using SPSS23 software by ANOVA and Chi-square tests in addition to the descriptive statistics.
Results: The mean DMFT was 10.25 (SD 4.67). Oral hygiene status was good in 16% of participants, moderate in 82%, and poor in 2%. There was no significant difference between girls and boys in terms of oral hygiene status (P=0.5). In all cases, 35.8% had class I malocclusion, 29.8% had class II malocclusion, and 14.6% had class III malocclusion. Class II malocclusion was more common in girls and class I in boys (P=0.01).
Conclusion: Dental caries and occlusal abnormalities were common among blind children and adolescents living in Mazandaran province. Addressing the oral and dental needs of the blind should be a priority for health policymakers in this province in Iran.

Background and Aims: Educational planning is one of the main areas of education and training, which plays an essential role in the optimal training of human resources. The aim of this study was to compare the educational program (curriculum) of general dentistry in Iran with that of several prestigious dental schools in the Middle East countries.
Materials and Methods: This is a descriptive comparative study using the dental education curricula of six prominent countries in the Middle East in the field of dental sciences. Their selection was based on similarities and common cultural, economic and social characteristics. After collecting the selected curriculums, four steps including description, interpretation, juxtaposition and comparison were done. Tables were drawn based on goals such as the number of years of education, mission, general goals, and the role of graduates in the medical system of that country.
Results: The educational curriculum of the countries reviewed in the Middle East have many similarities in terms of the number of years of study in the field of dentistry, the general mission and goals, and the role of students in the medical system of that country. The main differences were in the number and type of teaching units in the curriculum of this countries. The method of teaching and the distribution of topics in the curricula of the countries differentiated them from each other. According to the results of this study, the curriculum of the countries of Iran, Saudi Arabia and the UAE were the most similar among the countries of the Middle East. The teaching method and distribution of topics in the curricula of countries distinguished them from each other.
Conclusion: Countries that are based on Russian language education have a shorter number of years of education and are similar to Russia. However, countries with an American educational base such as Saudi Arabia, the United Arab Emirates, and even Iran have a longer academic years and more general similarities in educational content.