Journal of Dental School

Objectives To study components of oral health care system in some developed countries and propose a model for Iran.

Methods The present study was a qualitative, cross-sectional, and comparative research that took place in 2012. Oral health care systems in some developed countries have been reviewed to propose a framework for Iran. This framework has been discussed and reviewed by an expert panel using Delphi method.

Results A table presenting type of service provider, type of centers and personnel, and methods for reimbursement in oral health care delivery system has been discussed by an expert panel. The experts, with an average 75% agreement rate, agreed on the need for a basic oral health care package free of charge for under 18-year-olds, compulsory periodical check-up examinations, and guarantee for payment of the services by national insurance funds. Simplicity, comprehensiveness, focus on prevention and at risk age groups facilitate the adaptability of the model to various populations.

Conclusion An appropriate model for oral healthcare delivery system needs universal health insurance coverage, a basic service package focusing on preventive care with mandatory regular dental check-ups, participating of private practitioners, and financing services through government revenues, premium, and health tax.

Objectives Despite the importance to use face-bow record for transferring maxillary cast to articulator some dentists use average points to avoid the time taken and ease of use. The location of incisal point could help to set the maxillary cast or denture in an appropriate position in mounting stage. This study was designed to determine the incisal point location in antero-posterior and vertical dimensions in different facial forms and genders.

Methods Dental casts were obtained from the maxillary jaw of 44 dental students (male and female) and subsequently transferred to the articulator using an ear bow. The three dimensional location of the incisal point in relation to condylar axis was determined using a Coordinated Measuring Machine (CMM).Collected data were compared between male and female participants as well as those of oval, squared and tapered faces. For data analysis Student t test was employed to make the comparisons.

Results The mean distance between the incisal point and the center of the condylar axis in antero-posterior and vertical dimensions was 81.28 mm and 42.85 mm respectively. The mean antero-posterior distance was significantly higher among male students (Ρ<0.05). The mean vertical dimensions did not show any significant difference between male and female students (P>0.05). In square facial form, the mean antero-posterior distance was significantly higher compared to the ovoid facial form (P<0.05).

Objectives Root resorption is a dangerous side effect in orthodontics, and maxillary incisors are at the highest risk for root resorption. It is important to understand optimal force considerations for patients with altered root lengths.The purpose of this study was to investigate the effects of root length on stress distribution on roots by means of three-dimensional finite element method (FEM).

Methods Three dimensional FEM models of maxillary central and lateral incisors were made. Then, root length of the incisors was changed in the increments of 1 mm from 0-4 mm. Applying 50 g (0.5 N) of force perpendicular to the tooth crown simulated uncontrolled tipping. Stresses and strains for each model were calculated and Pearson correlation coefficient was used to analysis the data.

Results There were significant correlations between root length of incisors and maximum stress in PDL. In the centrals with various root lengths, maximum stress was between 0.010884 and 0.056520 MPa, and in the laterals, it was between 0.027297 and 0.221040 MPa. By reducing root length of incisors, the maximum stress in buccal apical (r= 0.933,p<0.001 and 0.995, p<0.001 prospectively) and lingual crestal areas (r= 0.974 p=0.005 and 0.992, p=0.001  respectively) were reduced.

Objectives This study aimed to assess the antimicrobial effects of aloe vera hydroalcoholic extract and 0.2% chlorhexidine (CHX) mouthwash on Streptococcus sanguinis (S. sanguinis), Streptococcus salivarius (S. salivarius) and Streptococcus mutans (S. mutans) in vitro.

Methods Four concentrations (25%, 50%, 75% and 100%) of hydroalcoholic extract of aloe vera were prepared. S. sanguinis, S. salivarius and S. mutans were cultured on tryptic soy agar, and a single colony was removed from each microorganism and the opacity of pure microbial suspension was set at 0.5 McFarland standard concentration. Brain heart infusion broth culture medium, different concentrations of aloe vera extract, 0.2% CHX mouthwash, negative (distilled water) and positive (penicillin) controls and 0.5 McFarland bacterial suspension were added to the tubes and incubated at 37°C for 5, 10, and 15 minutes. Then, the samples were cultured on tryptic soy agar and incubated at 37°C for 48 hours. Number of colony forming units (CFUs) in the groups was compared with two-way repeated measures ANOVA. For paired comparisons, Tukey's multiple comparisons test was used (P˂0.05).

Results The results showed significant effect of hydroalcoholic extract of aloe vera (25, 50, 75, and 100%) on the tested microorganisms but the mean CFUs following the use of 0.2% CHX was significantly less than that after using different concentrations aloe vera extract (P<0.001). Regardless of the type of the material, the number of CFUs decreased with increased exposure time.

Conclusion Aloe vera can be used alone or with CHX mouthwash to eliminate cariogenic bacteria.

Objectives The aim of this study is find a practical and easy way to histologically differentiate between two malignant tumors namely Adenoid Cystic Carcinoma (ACC) and Polymorphous Low-grade Adeno Carcinoma (PLGA) silver nitrate staining.

Methods In this cross-sectional study, 30 parrafin-embedded blocks of ACC and nine paraffin-embedded blocks of PLGA with the most acceptable standards were selected and stained with silver nitrate. Then the number and quality (size and pattern) of the stained spots in five random microscopic fields at 100× magnification (at least 100 cells) were evaluated. T-test was used to compare the number of dots between the two tumors while the quality of dots was compared with the Mann-Whitney U test.

Results The mean silver stainable nucleolus organizer region (AgNOR) count was 3/45 for ACC and 2/45 for PLGA. Significant differences were observed in the number of dots between ACC and PLGA (p=0.004), but there was no statistically significant difference between the two tumors in terms of quality of dots.

Conclusion AgNOR count can be useful as an available method in confirm the diagnosis of ACC and differentiate it from PLGA.

Objectives The first cause of tooth loss in developed countries is periodontitis. Chronic periodontitis is the most common form of periodontitis and it is characterized by loss of periodontal attachment, destruction of alveolar bone and eventual loss of teeth. Atorvastatin is a statin drug used for the treatment of high cholesterol. Statins can stop the inflammatory process by inhibiting the cholesterol pathway. Diclofenac is an NSAID with anti-inflammatory, anti-pyretic and analgesic effects. Its primary mechanism is through the inhibition of prostaglandins synthesis by the inhibition of the cyclooxygenase enzyme (COX). The purpose of this study is to compare the effects of local injected and oral intake of Diclofenac and atorvastatin on alveolar bone density measured in HUs with the use of a CT scan in a periodontitis-induced model in rats.

Methods Thirty rats were randomly divided into 6 groups of 5 rats each. Ligatures were placed around the left second maxillary molar to induce periodontitis for 10 days. Administration of 12.5 mg/kg of oral atorvastatin (group 1), 0.25 mg/kg of injectable atorvastatin (group 2), 7.5mg/kg of oral Diclofenac (group 3), 6.25mg/kg of injectable Diclofenac (group 4), the oral solvent without medicine as oral control (groups 5), and the injectable solvent without medicine as injectable control (group 6). In each group, the right side of maxilla was considered as control group (without ligature and drug interaction). At day eleven, the rats were sacrificed and the maxillary bone was separated from the soft tissue and fixed in 4% formalin. The prepared samples were then radiologically evaluated to determine the bone density with CT in fixed exposure conditions.

Results There was a statistically significant difference between the alveolar bone density of the oral atorvastatin group and the oral Diclofenac (P = 0.006). There was no statistical significant difference in alveolar bone density between the injectable atorvastatin and the injectable Diclofenac groups (P=0.228).

ObjectivesAcupuncture is one of the best known complementary therapies in Traditional Chinese medicine and has a history of more than 2500 years. Acupuncture stimulates the nervous system and shifts the perception of pain signals and also releases natural painkillers, such as endorphins and serotonin. Main aim of this article is to review related articles that have focused on acupuncture and its applications in dentistry. The other objective is to maintain a quick sketch of acupuncture use in dentistry for dental clinicians and to encourage them to use acupuncture with the knowledge of its advantages and disadvantages Dental clinicians have to be familiar with the applications of acupuncture for dental disorders because its successful use for dental conditions has been proven.

MethodsA detailed search was performed to identify systematic reviews and research/original and review articles, using PUBMED, EBSCO, GOOGLE SCHOLAR and CDSR from 1990 to 2017 in both languages English and Persian to clarify the application of acupuncture in dentistry.

ResultsVarious studies have shown that acupuncture can be used to manage wide range of disorders in dentistry such as dental pain, altering pain threshold, myofascial pain, temporomandibular disorders, gag reflex, dental anxiety, chronic muscle pain or spasm, TMD, Atypical facial pain, Headache (tension headache, migraine), (dry mouth),Nerve pain (neuralgia, especially trigeminal neuralgia, neuropathic pain, nerve injury), Paresthesia or anesthesia of the oral and perioral structures. However acupuncture's ability as dental analgesia or controlling post-operative pain after dental surgery as a single therapy is questionable.

Acupuncture and Dentistry

Objectives The purpose of this study was to present a case of regenerative endodontic procedure.

Case The maxillary 1^st premolar of a 9-year-old patient was diagnosed as necrotic. Since the tooth was immature, we decided to treat this tooth with regenerative endodontic procedure. After disinfection of the canal, bleeding was induced by lacerating the peri-apical tissues and a blood clot was formed. Orifice was sealed by MTA and the tooth was restored. 6-months and 1-year follow-ups showed increased root thickness and closure of the apical.

Conclusion It can be concluded that the regenerative endodontic procedure used in this study was successful since there was an evident development in root width.