Original Article

Effect of Thermocycling and Type of Restorative Material on Microleakage of Class II Restorations

Vaghareddin Akhavan-Zanjani, Elham Moravej-Salehi, Azam Valian

Journal of Dental School, Shahid Beheshti University of Medical Sciences, Vol. 34 No. 4 (2016), 6 March 2019 , Page 202-213

Objectives: Microleakage is a major cause of failure of dental restorations and results in development of secondary caries, tooth hypersensitivity and pulp pathosis. This study aimed to compare the microleakage of class II cavities filled with two types of composite resins and a compomer and subjected to thermocycling.

Methods: In this in vitro experimental study, class II cavities with a gingival margin below the cementoenamel junction (CEJ) and beveled enamel margins were prepared in proximal surfaces of 60 molar teeth. The teeth were randomly divided into three groups of 20 and restored with Spectrum TPH3 and Esthet X composites and Dyract eXtra compomer. Each group was randomly divided into two subgroups (n=10) of control and thermocycling (1000 thermal cycles). Dye penetration in occlusal and cervical margins was scored under a stereomicroscope. Data were analyzed using the Kruskal Wallis test and Mann Whitney U test (P<0.05).

Results: No significant difference was noted in microleakage of the three groups neither in the occlusal nor in the cervical margins in presence or absence of thermocycling (P>0.05). But, the microleakage in the cervical margins of compomer restorations was slightly higher than that of other groups especially after thermocycling.

Conclusion: Microleakage of composite restorations was not significantly different from that of compomer restorations in the occlusal or gingival margins in presence or absence of thermocycling.

Effect of Curing Time on Polymerization Rate of Bulk-Fill Composite Resins

Zahra Jaberi Ansari, Amir Ghasemi, Mohammad Taghi Vatandoust, Mojdeh Kalantar Motamedi

Journal of Dental School, Shahid Beheshti University of Medical Sciences, Vol. 34 No. 4 (2016), 6 March 2019 , Page 214-224

Objectives: The aim of this study was to compare polymerization depth of two bulk-fill and one conventional composite cured for different times.

Methods: This in vitro experimental study was conducted on 54 composite samples (2×4×10mm) fabricated of Tetric N-Ceram bulk-fill, x-tra fil bulk-fill, and Grandio conventional composite cured for 20, 30, and 40 seconds. The microhardness of samples was measured at 0.1, 2, 2.5, 3, 3.5, 4, and 4.5mm depths using a Vickers hardness tester. The results were analyzed using ANOVA, t-test, and Tukey’s test.

Results: The x-tra fil, Tetric N-Ceram and Grandio had maximum microhardness at 0.1mm depth after curing for 40 seconds. The microhardness decreased as the depth of composite increased. Microhardness of x-tra fil was higher than that of Tetric N Ceram. By increasing the curing time, the microhardness value of x-tra fil significantly increased up to 2mm depth. In Tetric N-Ceram, by increasing the curing time from 20 to 30 seconds microhardness increased significantly (P<0.05) by up to 3.5mm depth. By increase from 20 to 30 seconds, no significant change occurred in microhardness of Grandio samples at 0.1 and 2mm depths, but further increase from 30 to 40 seconds significantly increased the microhardness at all depths (P<0.05).

Conclusion: The maximum microhardness was obtained for x-tra fil at 0.1mm depth following 40 seconds of curing. Microhardness in deep areas (>2mm depth) depends on the type of composite, curing time and depth. Overall, 20 seconds of curing for x-tra fil and 30 seconds for Tetric N-Ceram seem appropriate.

Microleakage of Bulk-Fill Composites at Two Different Time Points

Niloofar Kianvash Rad, Bahar Javid, Narges Panahandeh, Amir Ghasemi, Ali Kamali, Gholamhasan Mohammadi

Journal of Dental School, Shahid Beheshti University of Medical Sciences, Vol. 34 No. 4 (2016), 6 March 2019 , Page 225-234

Objectives: Microleakage is the main concern in composite restorations. This study aimed to compare the microleakage of two bulk-fill and one conventional composite at two different time points.

Methods: Class II cavities were prepared in 60 premolar teeth and divided into six groups of 20. Groups 1 and 4 were incrementally filled with Grandio composite. Groups 2 and 5 were filled with X-tra fil bulk-fill composite. Groups 3 and 6 were filled with Tetric-N-Ceram bulk-fill composite in one layer. The samples were thermocycled for 5000 cycles between 25-55°C. In groups 1-3, the samples were incubated for 24 hours and then immersed in 1% methylene blue dye. Groups 4-6 were incubated for three months and then immersed in dye. All samples were mesiodistally sectioned and degree of microleakage was scored under a light microscope. The data were analyzed using Mann Whitney and Kruskal-Wallis tests.

Results: The results showed no significant difference among groups 1-5 and 6 in terms of microleakage (P>0.05) but a significant difference was noted between groups 1 and 4 in this regard (P=0.01). The microleakage in groups 4-6 was higher than that in groups 1-3 (P=0.02). Also, microleakage in gingival margins was greater than that in occlusal margins (P=0.02).

Conclusion: The microleakage of bulk-fill composites is comparable to that of conventional composites both at 24 hours and three months after restoration.

Comparison of pH and Flow Rate of Saliva After Using Black Tea, Green Tea and Coffee in Periodontal Patients and Normal Group

Sara Masoumi, Shahin Setoudehmaram, Ali Golkari, Zahra Tavana

Journal of Dental School, Shahid Beheshti University of Medical Sciences, Vol. 34 No. 4 (2016), 6 March 2019 , Page 235-343

Objectives: Periodontal pathogens need acidic environments to proliferate in periodontium, and their growth is affected by the salivary flow rate and pH of the mouth. Alterations in flow and acidity of saliva have an important effect on oral diseases such as periodontitis. This study was designed to compare salivary pH and flow rate before and after using green tea, black tea and coffee in patients with periodontitis and healthy subjects.

Methods: The present case control study was conducted on 60 subjects that were allocated into two groups: 30 subjects without periodontitis and 30 subjects with chronic periodontitis. Gingival index (GI), plaque index (PI), probing depth (PD) and clinical attachment loss (CAL) were recorded. Next, 5mL of saliva from both groups was collected for analysis before and after green tea, black tea and coffee rinsing and salivary pH and flow rate were recorded.

Results: The result showed significant increase in salivary flow rate and pH after rinsing of green tea in periodontitis group but there was no significant change in pH and flow rate after rinsing of black tea and coffee in both groups.

Conclusion: The results suggest that green tea causes a significant increase in salivary flow rate and pH and seems to be a safe and applicable adjunct treatment for periodontitis.

Assessment of the Relation of Mandibular Cortical Index and Gonial Angle Size in an Adult Iranian Population Using Digital Panoramic Radiography

Sanam Mirbeigi, Ehsan Tavakoli, Yasaman Sabaghzadegan, Fatemeh Ezoddiniardakani, Mahkameh Moshfeghi

Journal of Dental School, Shahid Beheshti University of Medical Sciences, Vol. 34 No. 4 (2016), 6 March 2019 , Page 244-252

Objectives: This study sought to assess the relation of mandibular cortical index (MCI) with age, gender and gonial angle size in an Iranian adult population using digital panoramic radiography.

Methods: We evaluated 370 digital panoramic radiographs of patients and divided them into five 10-year age groups. Each radiograph was assigned to low (≤120°) or high (≥125°) angle groups in terms of the gonial angle size. The MCI class was also determined for each individual. The multinomial logistic regression was used to assess statistical differences.

Results: The MCI class was significantly different between males and females and MCI class 3 had higher prevalence among older individuals. There was no statistically significant difference in distribution of MCI classes between individuals with high and low gonial angles.

Conclusion: Age-related changes in MCI support its potential use for detection of skeletal osteopenia.

Assessment of Stress in General Dentists in Tehran City

Ahmad Najafi, Narges Panahandeh, Abdolmajid Bahreinian, Siamak Sabour, Seyyed Bahaodin Mahmoodi

Journal of Dental School, Shahid Beheshti University of Medical Sciences, Vol. 34 No. 4 (2016), 6 March 2019 , Page 253-262

Objectives: This study sought to assess the level of stress in general dentists in the 2nd district of Tehran city in 2014 to find out the stressors and suggest strategies to overcome them.

Methods: This descriptive, analytical, cross-sectional study was conducted on 130 general dentists from the 2nd district of Tehran city selected via weighted randomization. Level of stress was assessed using Coudron stress questionnaire. Data were analyzed using SPSS version 20.0 and Spearman’s correlation coefficient, Chi square test and ordinal logistic regression tests. P<0.05 was considered statistically significant.

Results: All types of stress (occupational, life health, personal life and personality) were significantly correlated. Normal life health stress (compared to high stress) decreased occupational stress to approximately one third. Level of occupational stress was 2.5 times lower in subjects with normal level of stress in their personal life and 2 times lower in subjects with normal personality stress. Most dentists, irrespective of gender and marital status had high levels of occupational stress. Only 11.27% of those with a work experience of less than 10 years had normal life health stress. Personal life stress was significantly correlated with age, work place, and work experience (P<0.05).

Conclusion: Most dentists, irrespective of gender (male: 67.3%, female: 73%) and marital status (married: 66.3%, single: 74.2%) had high levels of occupational stress. The effects of age, gender, marital status, work place and work experience were variable on occupational, life health, personal life and personality stresses and depended on the type of stress assessed.

Case Report

Report of a Case of Hypodontia due to Ectodermal Dysplasia: Early Rehabilitation with Overdenture

Maryam Mohajerfar, Simindokht Zarrati, Yeganeh Memari

Journal of Dental School, Shahid Beheshti University of Medical Sciences, Vol. 34 No. 4 (2016), 6 March 2019 , Page 274-281

Alveolar ridge is underdeveloped in ectodermal dysplasia (ED). The available treatment plans include fixed, removable or implant-supported prostheses, alone or in combination.

A 5 year-old boy was referred for treatment to the Department of Prosthodontics, Tehran University of Medical Sciences with the chief complaint of missing teeth. Prosthodontic treatment was performed to improve mastication, esthetics, phonetics, and psychological support. Altering the alveolar height also provided a more pleasant musculocutaneous profile. Series of overdentures were fabricated in the same conventional manner to compensate for the patient’s growth.

Early treatment had a major impact on self-esteem, masticatory function, speech and facial esthetics of our patient. However, long-term success depends on regular recall appointments. 

Reviewed Article

Homeopathy in Dentistry and Oral Medicine: A review

Ghazal Kardanpour, Mostafa Rezaee, Ali Golkari, Fatemeh Lavaee

Journal of Dental School, Shahid Beheshti University of Medical Sciences, Vol. 34 No. 4 (2016), 6 March 2019 , Page 263-273

Objectives: Homeopathy is the most important field of alternative medicine. At present, over 3000 organic medications have been registered in the homeopathy pharmacopeia; out of which, 70% have herbal, 20% have mineral and the remaining have animal origins. Evidence shows that homeopathy may be beneficial in dentistry and oral medicine. However, this is a less known field for dentists. Therefore, this study aimed to do a review on the most common homeopathy medicines used for oral and dental problfems and to present it in a simple and practical way for general dental practitioners.

Review of Literature: Google Scholar and PubMed data bases were searched for any article related to both homeopathy and dentistry. Several recent meta-analyses, randomized control trials, animal and laboratory trials, and other interventional papers were studied.

Homeopathy drugs are basically produced from natural origin; they have less side effects in comparison with chemical drugs. In this method, only small doses of medications with low cost are used. The positive effects of homeopathy drugs on several oral conditions have been emphasized.

Conclusion: Homeopathy may be a suitable adjunct to conventional medicine for management of many conditions since it is affordable, effective and uplifting for patients.