فهرست مطالب

Frontiers in Dentistry
Volume:11 Issue: 6, Nov 2014

  • تاریخ انتشار: 1393/06/08
  • تعداد عناوین: 16
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  • Sara Ghadimi, Bahman Seraj, Hooman Keshavarz, Ahmad Reza Shamshiri, Razieh Abiri Pages 620-628
    Objective
    The purpose of this study was to evaluate the effect of an educational poster on elementary school health teachers’ knowledge about emergency management of traumatic dental injuries.
    Materials And Methods
    Before poster presentation, a questionnaire was distributed to 40 health teachers (30 in the study group and 10 in the control group). One month after poster distribution, the subjects were re-evaluated in both groups using the same questionnaire.
    Results
    The percentage of participating health teachers who answered the questions correctly after poster distribution regarding crown fracture was 93.3% in the test group vs. 60% in controls; for management of luxation and avulsion, the percentages for cases and controls were 63.3% vs. 40% and 100% vs. 60%, respectively. One month after distribution of the educational poster, rate of correct responses increased in management of crown fracture, luxation, and avulsion in the test group, but there was no improvement in controls (P<0.001).
    Conclusion
    Use of an educational poster enhanced the knowledge of health teachers. Use of posters is an effective way to inform teachers of the management of traumatic dental injuries.
    Keywords: Dental Trauma, Education, Management
  • Hamidreza Fattahi, Hamidreza Pakshir, Neda Afzali Baghdadabadi, Shervin Shahian Jahromi Pages 629-638
    Objective
    An increased overbite may be due to a skeletal or dental etiology that may influence treatment. The purpose of this study was to evaluate the skeletal and dentoalveolar features in patients with deep bite malocclusion in an Iranian population and to determine the most and least effective and contributory variables causing deep bite.
    Materials And Methods
    Lateral cephalograms and study casts of normal (n=85) and deep bite (n=85) subjects were used to evaluate skeletal and dentoalveolar variables. Data were analyzed statistically by independent t-test. The percentages of each variable within normal limits, less and more than one standard deviation were calculated for deep bite subjects.
    Results
    The most significant skeletal contributing factors were gonial and basal angles, as well as the posterior facial height, ramus length, lower anterior facial height and upper anterior facial height. An increased curve of spee and decreased mandibular first molar height were predominant dental variables in the deep bite group. The variables with the greatest variances from the normal limit were the ratio of the lower anterior facial height to the total anterior facial height, the lower anterior facial height to the upper anterior facial height and the ramus length.
    Conclusion
    The counterclockwise rotation of the mandible and the increased curve of spee were the dominant feature of deep bite malocclusion.
    Keywords: overbite, Cephalometry, Malocclusion
  • Aliasghar Soleymani, Zahra Bahrololoomi, Shahrzad Javadinejad, Parisa Salehi Pages 639-643
    Objective
    Micro-leakage, one of the major reasons for recurrent decays, may lead to uncontrollable flow of liquids, pulp inflammation and peri-apical pathology. The purpose of this in vitro study was to evaluate micro-leakage of pit and fissure sealants after using three different pit and fissure preparation techniques: 1) acid etching, 2) fissure enameloplasty and acid etching, and 3) air abrasion and acid etching.
    Materials And Methods
    Sixty-nine extracted sound molars and premolars were randomly divided into three groups (23 samples in each group). Teeth were prepared using one of three occlusal surface treatments. Then the sealant was applied on the occlusal fissures of all teeth. The teeth were thermocycled and stored in normal saline. All teeth were sealed apically and coated with nail varnish and then were immersed in a 2% solution of methylen blue. Two buccolingual sections were made. The surfaces were scored 0 to 3 for the extent of micro-leakage using a stereomicroscope. Data were analyzed by Kruskal- wallis and Dunn procedure.
    Results
    Enameloplasty and acid etching were significantly different regarding micro-leakage (P= 0.016), but no significant difference in micro-leakage was observed between air abrasion and the other methods.
    Conclusion
    Enameloplasty followed by acid etching produced significantly less micro-leakage than the acid etching technique. Air abrasion acid etching was better than the acid etching technique in reducing micro-leakage too.
    Keywords: Fissure Sealants, Air Abrasion, Dental
  • Maryam Khoroushi, Alireza Eshghi, Alireza Rezvani Pages 644-654
    Objective
    Bioactive glass air abrasion is a conservative technique to remove initial decalcified tissue and caries. This study examined the shear bond strength of composite resin to sound and decalcified enamel air-abraded by bioactive glass (BAG) or alumina using etch-and-rinse and self-etch adhesives.
    Materials And Methods
    Forty-eight permanent molars were root-amputated and sectioned mesiodistally. The obtained 96 specimens were mounted in acrylic resin; the buccal and lingual surfaces remained exposed. A demineralizing solution was used to decalcify half the specimens. Both sound and decalcified specimens were divided into two groups of alumina and bioactive glass air abrasion. In each group, the specimens were subdivided into two subgroups of Clearfil SE Bond or OptiBond FL adhesives (n=12). Composite resin cylinders were bonded on enamel surfaces cured and underwent thermocycling. The specimens were tested for shear bond strength. Data were analyzed using SPSS 16.0 and three-way ANOVA (α=0.05). Similar to the experimental groups, the enamel surface of one specimen underwent SEM evaluation.
    Results
    No significant differences were observed in composite resin bond strength subsequent to alumina or bioactive glass air abrasion preparation techniques (P=0.987). There were no statistically significant differences between the bond strength of etch-and-rinse and self-etch adhesive groups (P=1).Also, decalcified or intact enamel groups had no significant difference (P=0.918). However, SEM analysis showed much less enamel irregularities with BAG air abrasion compared to alumina air abrasion.
    Conclusion
    Under the limitations of this study, preparation of both intact and decalcified enamel surfaces with bioactive glass air abrasion results in similar bond strength of composite resin in comparison with alumina air abrasion using etch-&-rinse or self-etch adhesives.
    Keywords: Air abrasion, bond strength, composite resin, enamel
  • Ahmad Rohanian, Ghasem Ommati Shabestari, Somayeh Zeighami, Mohammad Javad Samadi, Ahmad Reza Shamshiri Pages 655-664
    Objectives
    Some manufacturers claim to have produced new irreversible hydrocolloids that are able to maintain their dimensional stability during storage. The present study evaluated the effect of storage time on dimensional stability of three alginates: Hydrogum 5, Tropicalgin and Alginoplast.
    Materials And Methods
    In this experimental in-vitro trial, a total of 90 alginate impressions were made from a Dentoform model using Hydrogum 5, Tropicalgin and Alginoplast alginates. The impressions were stored in a sealed plastic bag without a damp paper towel for 0, 24, 48, 72 and 120 hours and then poured with type III dental stone. Cross-arch (facial of 6 to facial of 6 on the opposite side) and antero-posterior (distal of right first molar to the ipsilateral central incisor) measurements were made with a digital caliper on the casts. Data were analyzed by two-way and one-way ANOVA and Tukey’s post-hoc test (P<0.05).
    Results
    Alginate type and the pouring time significantly affected the dimensional stability of alginate impressions (both Ps<0.001). Pouring of Hydrogum 5 impressions can be delayed for up to 120 hours without significant dimensional changes. Alginoplast impressions may be poured after 72 hours, but Tropicalgin should be poured immediately and the storage time should not be more than 24 hours.
    Conclusion
    Immediate pouring of alginate impressions provides the highest accuracy in reproducing the teeth and adjacent tissues; however, this study demonstrated that pouring may be delayed for up to five days using extended-pour (Hydrogum 5) alginates.
    Keywords: Dimensional Measurement Accuracy, Dental Impression Materials, Alginates, Plaster Cast
  • Siavash Savadi Oskoee, Mahmoud Bahari, Soodabeh Kimyai, Paria Motahari, Mohammad Jafar Eghbal, Saeed Asgary Pages 665-671
    Objective
    Immediate restoration after vital pulp therapy is essential in order to create and maintain effective coronal seal.Purpose of Study: The aim of this study was to evaluate the shear bond strength of recently used pulp capping materials: white mineral trioxide aggregate (MTA), and calcium enriched mixture cement (CEM) to composite resin with the use of etch-and-rinse and self-etch adhesive systems and compare them with the bond strength of commonly used resin modified glass ionomer (RMGI) cement.
    Materials And Methods
    Forty specimens from each test material were fabricated, measuring 4 mm in diameter and 2 mm in depth. The specimens of each material were divided into 2 groups of 20 specimens according to the adhesive system (Single Bond vs. Clearfil SE Bond) used for bonding of resin composite. The shear bond strength values were measured at a crosshead speed of 1.0 mm/min and fractured surfaces were examined. Data were analyzed using two-way ANOVA and a post hoc Tukey’s test (P<0.05).
    Results
    Analysis of data showed a significantly higher bond strength for RMGI compared to MTA and CEM (P<0.001); however, no significant differences were observed in the bond strength values of MTA and CEM (P=0.9). Furthermore, there were no significant differences in relation to the type of the adhesive system irrespective of the type of the material used (P=0.95) All the failures were of cohesive type in RMGI, MTA and CEM.
    Conclusion
    Bond strength of RMGI cement to composite resin was higher than that of MTA or CEM cement irrespective of the type of the adhesive system.
    Keywords: Mineral trioxide aggregate, Composite resin, Bond strength
  • Mina Biria, Gita Eslami, Elaheh Taghipour, Alireza Akbarzadeh Baghban Pages 672-679
    Objective
    In the recent years, herbal oral hygiene products have gained increasing attention. The aim of this study was to assess the effects of three types of mastic gums on the level of Mutans streptococci, Lactobacilli and pH of the saliva.
    Materials And Methods
    Forty-two students in the age range of 20-30 years were divided into three parallel groups; each of them separately used pure mastic gum, xylitol mastic gum and probiotic mastic gum for three weeks. Number of microorganisms and pH of the saliva were assessed before and after the intervention. The data were analyzed using Wilcoxon Signed Rank, paired-sample-t, Kruskal-Wallis and Tukey’s post-hoc tests and One-way ANOVA.
    Results
    Level of Mutans streptococci showed a significant reduction compared to its baseline value in all three groups (P<0001 for all). Salivary Lactobacillus count increased in the groups using pure and xylitol mastic gums but decreased in the group using probiotic type, albeit these changes were only significant in the group using probiotic mastic gum (P<0.001). Use of pure and xylitol mastic gums increased the pH of the saliva but not significantly. In the group using probiotic mastic gum, the pH of the saliva decreased significantly (P=0.029).
    Conclusion
    Three weeks use of all mastic gums resulted in a significant drop in the number of Mutans streptococci in the saliva. However, the drop in the saliva pH due to the use of probiotic mastic gum is not in favor of dental health.
    Keywords: Mastic gum, Saliva, Mutans streptococci, Lactobacilli
  • Zahra Jaberi Ansari, Narges Panahandeh, Zahra Sadat Tabatabaei Shafiei, Alireza Akbarzadeh Baghban Pages 680-686
    Objective
    Statement of Problem: Adequate bond strength between glass ionomer cements and composite resin is necessary for the success of the sandwich technique.Purpose of Study: This study assessed the micro-shear bond strength of composite resin to glass-ionomer cements (GIC) using self-etch adhesives with different pH values.
    Materials And Methods
    One hundred specimens (6×4×2 mm) were made using Fuji II and Fuji II LC GICs and treated with different adhesives as follows: Group 1:Fuji II+ Adper Prompt L-Pop, Group-2: Fuji II+SE bond, Group-3: Fuji II + AdheSE, Group-4:Fuji II+ Protect bond, Group-5: Fuji II + Single bond, Group-6:Fuji II LC+ Adper Prompt L-Pop, Group-7: Fuji II LC+SE bond, Group-8:Fuji II LC+ AdheSE, Group-9: Fuji II LC+ Protect bond, and Group-10: Fuji II LC+ Single bond. Each group consisted of 10 specimens. A cylinder of Z100 composite resin was placed on each sample and light cured. After 24 hours of water storage (37˚C), the specimens were subjected to micro-shear bond strength tests (0.5 mm/min). Data were analyzed using two-way ANOVA and Tukey’s test.
    Results
    The mean micro-shear bond strength of groups 1-10 was 11.66±1.79, 16.50±1.85, 18.47±1.77, 13.95±1.77, 15.27±1.49, 15.14±0.90, 20.03±1.19, 17.48±3.00, 16.24±1.98 and 16.03±1.49 MPa, respectively. There were significant differences between groups 1 and 7 (P<0.05). No significant difference was observed between other groups (P>0.05). Fuji II LC showed higher bond strength than Fuji II (P<0.05).
    Conclusion
    Type of self-etch adhesive had no significant effect on micro-shear bond strength of glass-ionomer to composite resin. Resin modified glass ionomer cement (RMGIC) exhibited higher bond strength than the conventional GIC.
    Keywords: Adhesives, Adper Prompt self, etch, Clearfil SE bond, Composite resins, Glass ionomer cements
  • Mojgan Paknejad, Amirreza Rokn, Simak Yaghobee, Pantea Moradinejad, Mohadeseh Heidari Pages 687-695
    Objective
    The purpose of this study was to evaluate the efficacy of two types of bone substitutes, Bio-Oss and NuOss, for repair of bone defects.
    Materials And Methods
    This study was performed on the calvaria of 14 New Zealand rabbits. The 6mm critical size defect (CSD) models of bone regeneration were used. Three CSDs were created in each surgical site. The first defect was filled with NuOss, the second one with Bio-Oss and the third one remained unfilled as the control. After healing periods of one and two months (seven animal for each time point), histological and histomorphometric analyses were carried out to assess the amount of new bone formation, presence of inflammation, foreign body reaction and type of new bone. Qualitative variables were analyzed by multiple comparisons, Wilcoxon, Friedman and Mann Whitney tests. Quantitative variables were analyzed using the Mann-Whitney and Wilcoxon tests. Level of statistical significance was set at 0.05.
    Results
    The level of inflammation was not significantly different at four and eight weeks in the Bio-Oss (P=0.944), NuOss (P=1.000) and control groups (P=0.71). At four weeks, foreign body reaction was not observed in Bio-Oss, NuOss and control groups.There was no significant difference in the type of the newly formed bone at four and eight weeks in any group (P=0.141 for Bio-Oss, P=0.06 for NuOss and P=0.389 for the control group).
    Conclusion
    Deproteinized bovine bone mineral can be used as a scaffold in bone defects to induce bone regeneration.
    Keywords: Bone regeneration, Deproteinized, Bovine bone, Bio, Oss, Adequate
  • Shishir Ram Shetty, Subhas G. Babu, Prasanna Kumar Rao, Sham Kannepady Kishor, Kumuda Arvind Rao, Renita Castelino Pages 696-702
    Objective
    In our previous studies we have evaluated the role of antioxidants and trace elements in potentially malignant disorders and cancers of the oral cavity, taking into consideration the importance of antioxidants as biomarkers in cancer detection. We felt that other than evaluation, the correlation and interdependence that existed among antioxidants and trace elements require further evaluation in order to develop a better understanding.
    Materials And Methods
    Serum and salivary zinc, glutathione, and superoxide dismutase levels were evaluated in 65 healthy controls, 115 subjects with potentially malignant oral disorders, and 50 subjects with oral squamous cell carcinoma, using the atom absorption photometry, [5, 5-Dithiobis (2 nitrobenzoic acid)], and nitroblue tetrazolium methods, respectively.
    Results
    Serum zinc and serum glutathione showed significant positive correlation (r=0.76, P=0.01). Similarly, salivary glutathione and salivary zinc levels had a positive correlation (r=0.68, P=0.01). Serum superoxide dismutase showed a strong positive correlation with serum zinc (r=0.64, P=0.01). Similarly, there was a moderate positive correlation between salivary superoxide dismutase and salivary zinc (r=0.67, P=0.01).
    Conclusion
    Our findings showed that trace elements and antioxidants exhibited interdependence in serum, as well as in saliva, in both physiologic and pathologic states such as oral cancer.
    Keywords: Antioxidants, Serum, Saliva, Micronutrients, Zinc, Copper, Superoxide dismutase, Glutathione
  • Barani Kumarasamy, Sunayana Manipal, Prabu Duraisamy, Adil Ahmed, Vidhya Rekha, Jeevika C Pages 703-710
    Objectives
    Use of alternative medicine to control oral streptococci is a new topic worthy of further investigation.This study aimed to elucidate the dose-dependent anti-bacterial activity of crude aqueous extract of ripe Morinda citrifolia L. (Family: Rubiaceae) fruits against oral streptococci i.e. Streptococcus mutans and Streptococcus mitis, that cause dental caries in humans.
    Materials And Methods
    Fresh ripe M. citrifolia fruits (750g) were ground in an electronic blender with sterile water (500ml). The crude aqueous extract was lyophilized to yield a brown colored powder. Various concentrations (1000-100µg/ ml) of the extract were tested for its anti-bacterial activity (Kirby and Bauer method) against whole cells of S. mutans and S. mitis. Minimum Inhibitory Concentration (MIC) was determined by micro-dilution method, using serially diluted (2 folds) fruit extract, according to the National Committee for Clinical Laboratory Standards (NCCLS).
    Results
    Crude aqueous extract (1000µg/ ml) of ripe M. citrifolia fruits effectively inhibited the growth of S. mutans (19±0.5 mm) and S. mitis (18.6±0.3 mm) compared to the streptomycin control (21.6±0.3 mm). The growth inhibition was clearly evident with “nil” bacteriostasis, even after 48 hours of incubation at 37°C. The MIC of the extract for S. mutans and S. mitis was 125 µg and 62.5 µg, respectively.
    Conclusion
    Our results suggest that phytochemicals naturally synthesized by M. citrifolia have an inhibitory effect on oral streptococci. Furthermore, purification and molecular characterization of the “bioactive principle” would enable us to formulate a sustainable oral hygiene product.
    Keywords: Morinda citrifolia L., Streptococcus mutans, Streptococcus, mitis, Anti, bacterial activity
  • Anshul Jain, Shridhar D. Baliga Pages 711-714
    One of the complications during a routine dental implant placement is accidental ingestion of the implant instruments, which can happen when proper precautions are not taken. Appropriate radiographs should be taken to locate the correct position of foreign body; usually the foreign body passes asymptomatically from gastrointestinal tract but sometimes it may lead to intestinal obstruction, perforations and impactions. The aim of this article is to report accidental ingestion of 19 mm long screw driver by a senile patient.
    Keywords: Implants, Ingestion, Foreign body, Screw driver, Hemorrhage, Perforation
  • Abolfazl Saboury, Ali Gooya Pages 715-750
    Screw-retained implant restorations have an advantage of predictable retention as well as retrievability, and obviate the risk of excessive sub-gingival cement commonly associated with cement retained implant restorations. Screw-retained restorations generally have screw access holes, which can compromise esthetics and weaken the porcelain around the holes. The purpose of this study is to describe the use of a separate overcasting crown design to cover the screw access hole of implant screw-retained prosthesis for improved esthetics.
    Keywords: Implant, Esthetic, Fixed Prosthesis
  • Mahdi Pazouki, Nasrollah Saghravanian, Maryam Zamanzadeh Pages 721-725
    Amelanotic melanoma is a variant of malignant melanoma comprising 2% to 8% of all malignant melanomas. The amelanotic presentation of melanoma in the oral cavity is extremely rare and has been reported only occasionally in the literature. Moreover, the lack of melanin makes these tumors difficult to diagnose than that of pigmented lesions and the prognosis tends to be poorer. Herein, we report an amelanotic melanoma involving the oral mucosa of the maxilla in a 27 year-old male.
    Keywords: Amelanotic, Melanoma, Maxilla, Oral
  • Preetham Jain, Krishnamurthi Ananthnarayan, Suma Ballal, Velmurugan Natanasabapathy Pages 726-732
    The main objective of nonsurgical endodontic treatment is to eliminate micro-organisms from the root canal system. Adequate knowledge of the root canal morphology and its complexities is essential to render successful endodontic treatment. Variations in tooth form and morphology may be found in the form of anomalous cusps in the crown region or additional roots. In permanent molars, changes in the crown morphology may occur either in the form of an additional tooth (paramolar) or supernumerary cusp termed as “paramolar tubercle”.
    Keywords: Paramolar Tubercle, Endovac Irrigation system, CBCT
  • Marcelo Goiato, Daniela Dos Santos, Lisiane Bannwart, Marcela Haddad, Leonardo Pereira, Aljomar Filho Pages 733-739
    Several factors including cancer, malformations and traumas may cause large facial mutilation. These functional and aesthetic deformities negatively affect the psychological perspectives and quality of life of the mutilated patient. Conventional treatments are prone to fail aesthetically and functionally. The recent introduction of the composite tissue allotransplantation (CTA), which uses transplanted facial tissues of healthy donors to recover the damaged or non-existent facial tissue of mutilated patients, resulted in greater clinical results. Therefore, the present study aims to conduct a literature review on the relevance and effectiveness of facial transplants in mutilated subjects. It was observed that the facial transplants recovered both the aesthetics and function of these patients and consequently improved their quality of life.
    Keywords: Composite Tissue Allotransplantation, Facial Transplantation, Microsurgery, Rehabilitation