Journal of Dental School
Volume:32 Issue: 2, 2014

Secondary caries is a common problem in dental treatments and its occurrence is attributed to several factors. The present study aimed at assessing the prevalence of secondary caries in posterior teeth of patients presenting to the Department of Operative Dentistry, Shahid Beheshti Dental School. This descriptive study was conducted on 350 patients with 1,339 posterior teeth restored with amalgam or composite resin. Restorations older than 3 years were evaluated. Data regarding presence or absence of secondary caries, age of restoration, location of receiving dental care, tooth brushing technique and use of dental floss and mouthwash were recorded in a questionnaire. Statistical analysis was done using chi-square test. The prevalence of secondary caries was 26% among the understudy patients. MOD restorations (19.2%) had the highest prevalence of secondary caries. Composite restorations had higher prevalence of secondary caries compared to amalgam restorations (p=0.01). Teeth restored in private dental offices had a higher prevalence of secondary caries compared to those restored in university clinics (P=0.007). Patients who used mouthwash had a significantly lower prevalence of caries recurrence (P=0.05). The prevalence of secondary caries in patients presenting to the Department of Operative Dentistry of Shahid Beheshti Dental School was higher in the MOD restorations, composite restorations and teeth restored in private dental offices finally it was less in the patients using mouthwash.

Different techniques have been suggested for the repair of bone defects at the injured sites. Use of biomembranes, or application of plasma rich in growth factor (PRGF) at the site of proliferation of osteoblasts are among the suggested techniques. The current study aimed to compare the biocompatibility of human periodontal ligament fibroblasts (hPLF) cultured on Hypro-Sorb F, Pericardium and Tutodent resorbable membranes coated with PRGF. This experimental study was conducted on four resorbable membranes namely Hypro-Sorb F, Pericardium, Tutodent and Vicryl. Fibroblast cells isolated from the periodontal ligament of premolar tooth were passaged three times and 105 cells/cm2 were cultured on membranes coated with PRGF. After 72 hours, the cells were evaluated in terms of biocompatibility and alkaline phosphatase (ALP) activity. Statistical analysis was carried out using one-way ANOVA. PRGF increased cell adhesion and Tutodent membrane coated with PRGF showed the highest cell adhesion compared with Hypro-Sorb F and Pericardium membranes (P=0.005). PRGF increases cell viability and ALP activity of cells on biomembranes. PRGF treatment increases the adhesion of fibroblast cells to these membranes.

Numerous studies have emphasized on the importance of developing an ideal educational system for high-quality dental education. The present study sought to assess the perception of dental students on operative dentistry education in Department of Restorative Dentistry, Shahid Beheshti Dental School, Tehran, Iran. In this descriptive cross-sectional study, 220 students were selected and given a questionnaire including demographic, grades in operative dentistry clinical and didactic courses, the efficacy of preclinical courses in preparing students for clinical practice, ways to improve competency and expertise of students for clinical setting, student’s opinion on relating the assessment tests with the taught topics, required instructional resources for assessment of students’ proficiency in restorative dentistry and satisfaction rate of students with clinical courses offered in the current curriculum. Data were analyzed using descriptive statistics (SPSS 18). The Clinical Operative Dentistry 3 and Preclinical Dental Anatomy received a mean satisfaction score of 3.31 and 2.74, respectively. Furthermore, 57.3% of students highly emphasized the necessity of studying textbooks of restorative dentistry. 50.5% of students believe that lectures by instructors along with active participation of students were the best method for didactic operative dentistry courses. In addition, 60.5% were in favor of using a combination of textbooks, lectures, and class notes for the assessment of students’ learning. The present study revealed that Department of Restorative Dentistry in Shahid Beheshti Dental School is successful in its teaching and achieving students’ satisfaction. However, some revisions need to be made in educational methods and contents and active participation of students in class discussions should be encouraged as well.

For the assessment of primary arch form, different methods have been used including qualitative classifications, inter-canine and inter-molar widths and quantitative and numerical methods using mathematical models. The purpose of this study was to compare the validity and reliability of Cast Analyzer X Iranian software with those of Curve Expert Professional version 1.1 for arch form construction based on mathematical models. This diagnostic, in-vitro study was performed on 18 sets of dental casts with normal Class I occlusion. The clinical buccal points (bracket attachment sites)(CBPs) were marked on each tooth and their spatial coordinates were digitized using a three-dimensional (3D) laser scanning system. These coordinates were entered in Cast Analyzer X and Curve Expert software programs. Arch forms were constructed by the software programs using Brown’s beta function, Noroozi’s beta function and fourth order polynomial equation. The root mean square (RMS) of the distance from reference points to their corresponding points on the curve was calculated. The RMS values in the two software programs were compared. The RMS values in Brown’s beta function, Noroozi’s beta function and fourth order polynomial equation were significantly different in the Cast Analyzer X software (P<0.001) and the fourth order polynomial equation had the lowest RMS. The difference in RMS values between the two software programs was not clinically considerable and was 0.45 and 0.68 mm for the fourth order polynomial equation and Brown’s beta function, respectively. Considering the RMS values, the fourth order polynomial equation is the most suitable analysis for describing normal dental arch forms best fitted with the CBPs. Although the difference between the two software programs was statistically significant, this difference was not clinically noticeable. The RMS value was lower in Cast Analyzer X and consequently the fitting of curves with the landmarks (CBP) was better in the Iranian software.

At present, growth factor-containing products such as enamel matrix derivatives, recombinant bone morphogenetic protein (rh-BMP), recombinant platelet derived growth factor and platelet rich plasma (PRP) have gained increasing attention. PRP is an autologous source of platelet growth factors used to enhance healing of soft and hard tissues. PRP has gained popularity due to its autologous nature, easy procurement and low cost. Review of Literatures: This study focuses on procurement and clinical applications of PRP. Controversy exists regarding the efficacy and applications of PRP and longitudinal studies are required to further elucidate this subject.