Journal of Dental School, Shahid Beheshti University of Medical Sciences

Objectives: Maintaining pulp vitality is a main goal in restorative dentistry. Introduction of pulp capping agents paved the way to eliminate the shortcomings of these materials and obtain successful restorations. On the other hand, nanotechnology is an emerging field of science with increasing use in dental materials. This study sought to assess the effect of addition of nano-TiO₂, nano-SiO₂ and nano-Al₂O₃ on compressive strength of five hydraulic cements.

Methods: In this in vitro, experimental study, three experimental formulations of nano hybrid MTA, MTA Angelus and MTA Angelus+ nano-oxide particles cements were placed in molds measuring 4±0.1mm in internal diameter and 6±0.1mm in height made of stainless steel (ISO9917-1). Ten samples were fabricated for each of the five groups of materials. Sound samples were stored at 37°C and 95±5% humidity and were subjected to compressive strength testing in a universal testing machine at a crosshead speed of 0.5mm/minute after 24 hours and one month. Two-way ANOVA, one-way ANOVA and independent samples t-test were used for comparison of compressive strength of groups at different time points.

Results: The highest compressive strength belonged to MTA Angelus+ nanohydroxyapatite and nano-hybrid MTA C at 24 hours and 30 days, respectively. The lowest compressive strength belonged to nano-hybrid MTA B and MTA Angelus at 24 hours and 30 days, respectively (P<0.05).

Objectives: While great advances have been made in the field of pediatric dentistry, creating a friendly relationship with pediatric patients and getting them to readily accept dental treatment and cooperate remains challenging. Cooperation by children can affect the quality of dental visit and the required time for the treatment. Dentists’ attire could be one of the factors that significantly affect children’s cooperation. The aim of this study was to assess children’s preferences towards dentists’ attire and to determine the influence of its design, color, and other factors on treatment acceptance.

Methods: A total of 103 children aged between 6-12 years were randomly divided into three groups (68 children in two study groups and 35 children in one control group). The children were examined by the pediatric dentists wearing different attires. Two questionnaires were designed; one was supposed to be answered by the parents before the dental visit and one by the children after the visit.

Results: The majority of children preferred the shirts that were adorned with Winnie the Pooh, while the treatment acceptance was not significantly different between the groups. Sex, age, number of family members, birth order, patient’s personality type, and parents’ educational level had no significant impact on treatment acceptance.

Conclusion: Although the attire design did not significantly affect treatment acceptance, it helped to establish a good relationship with pediatric patients in their first visit. The results help pediatric dentists choose attire that are better received by pediatric patients.

Objectives: The purpose of this study was to determine the frequency of all odontogenic cysts (OCs) along with age range, gender distribution, and the site of involvement over a 10-year period (March 2001 to March 2011) and to compare these data with findings from other surveys.

Methods: The archives of departments of oral and maxillofacial pathology from Shahid Beheshti and Tehran University of Medical Sciences were retrieved and analyzed for demographic data such as age, gender, location and histopathological diagnosis of OCs.

Results: Of the 8,563 biopsy samples that were received, 1,518 (17.7%) were diagnosed as OCs. Radicular cyst was the most common diagnosis (33.2%), followed by dentigerous cysts (24.1%), and odontogenic keratocysts (18.6%). OC occurred 59.3%, 40.6% in male and female respectively. Mandibular involvement was 62.4% while in maxilla was 37.6%.

Conclusion: Our study provided demographic data on a large series in Iran, a Southwest Asian country. In our study, radicular cysts, the most common OC, had a lower frequency compared to that reported in most other studies. On the other hand, calcifying OCs seem to be more prevalent in the Iranian population compared to other populations male to female to female ratio was 1.45:1.

Objectives: The purpose of this study was to evaluate whether intra-canal application of controlled direct electric current (DEC) could accelerate the amount of orthodontic tooth movement (OTM) in young adult mixed breed dogs.

Methods: Fourth premolars of both jaws of five young adult mixed breed dogs were divided into two groups of control and experimental groups. Orthodontic force was applied to both groups using an active NiTi push coil spring. Direct electric stimulation (15µA DC) was conducted by intra-canal usage of electric potential (1.5v). The experimental teeth were compared with controls in terms of clinical OTM results measured with an electronic caliper every two weeks (four time intervals). The animals were sacrificed one month (T2) or two months (T4) after initiation; and tissue sections were decalcified for histological evaluation. The data were analyzed using SPSS 16, Shapiro-Wilk test and paired t-test.

Results: Measurements revealed a statistically significant increase in OTM at electrically stimulated sites compared to the control sites in just one time interval (T3: after four weeks) (P< 0.05). Histological sections also showed increased osteoblastic and osteoclastic activity at tension and compression sides of the experimental group compared to the control group, respectively at both time intervals (T2 and T4).

Conclusion: Direct intra-canal electric current applied by a miniature electric device is effective for increasing the rate and amount of OTM in canine experimental model.

Objectives: Radiomorphometric indices measured on simple radiographic images can be used for qualitative and quantitative assessment of bone. Panoramic radiographic imaging can therefore assist dentists in early detection of osteoporosis in patients. Considering the effect of ethnic and environmental factors on development of osteoporosis and absence of normal values of radiomorphometric indices for the Iranian population, which results in use of normal values of other ethnicities for determining the presence or absence of osteoporosis in patients, the present study was conducted to evaluate radiomorphometric indices in patients presenting to a private oral and maxillofacial radiology clinic in Rafsanjan, Iran.

Methods: The present cross-sectional study examined 385 eligible patients who met the inclusion criteria. Their demographic characteristics including age, gender and level of education were recorded. Their panoramic radiographic data, including radiomorphometric indices such as mandibular cortical index (MCI), antegonial index (AI), and gonial index (GI), were evaluated on each image. Multiple logistic regression was used to evaluate the effect of variables on mandibular bone radiomorphometric indices.  P-value less than 0.05 was considered statistically significant.

Results: The mean AI and GI were 2.19±0.56 and 0.87±0.31mm, respectively. In assessment of MCI, since none of the patients fell under the C3 category, all patients were categorized as C1 or C2. Assessment of demographic variables and radiomorphometric indices showed that age had a significant relationship with MCI and AI while gender had a significant relationship with GI.

Conclusion: Radiomorphometric indices can be used to assess the risk of osteoporosis in patients.

Objectives: The aim of this study was to assess the efficacy of aloe vera and green tea mouthwash for reducing pain after periodontal pocket reduction surgery.

Methods: This randomized, split-mouth, double-blind, cross-over clinical trial was carried out on 45 patients between 25 and 50 years of age requiring pocket reduction surgery. Patients underwent bilateral surgeries in two sessions. After the first surgery, the patients were randomized to receive either mouthwash or placebo for 10 days; then, each group used the other product for the same time period. The parameters assessed following each procedure were the numeric pain rating scale (NPRS) and number of painkillers taken by patients to alleviate postoperative pain. Also, patients were requested to report side effects, if any, after using the mouthwash.

Results: The reported postoperative pain score was significantly lower after using the aloe vera and green tea mouthwash compared to the placebo only in the first postoperative day (P=0.002). Furthermore, number of analgesic tablets used in the first postoperative day was significantly lower than that in the control group (P=0.007).

Conclusion: Our results indicated that patients experienced significantly less early postoperative pain when they used aloe vera and green tea mouthwash. Thus, its application can be recommended to decrease pain after periodontal pocket reduction surgery.

Facial defects not only impact on the function and quality of life but also affect the psychological well-being and social behavior of patients. A nasal prosthesis can re-establish the esthetics and anatomical contour in patients with mid-facial defects, often more effectively than surgical reconstruction. For successful results, many factors such as retention, texture, color match and blending of tissue with the prosthesis must be taken into account. The aim of this clinical report was to describe a modified technique for rehabilitation of a nasal defect with suitable adaptation. This provisional prosthesis was made to restore the esthetic appearance of the patient with a mechanically retained design using a spectacle glass frame without inserting craniofacial implants.

The attrition of anterior teeth leads to the loss of efficient anterior guidance, which protects posterior teeth from wear during lateral excursions. This clinical report describes a 48-year-old man with diagonal tooth wear and posterior mandibular tooth loss. The clinical diagnosis was based on a complete oral examination, photos, functional analysis of lateral excursion movements, general health condition and behavioral aspects such as diet and bruxism.  A mandibular partial overlay denture was used to reestablish the occlusal plane after the decision of restoring the vertical dimension of occlusion (OVD) by anatomical landmarks and physiological measurements. Once the compatibility of new OVD was approved and accepted, and followed for six months, fixed implant and tooth supported restorations were fabricated.

A satisfactory clinical result was achieved by restoring OVD by 7 mm and avoiding advanced periodontal crown lengthening. Successful full mouth rehabilitation for a severely worn dentition can be achieved through good clinical management with long-term success to improve the quality of life.