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Dental Materials and Techniques - Volume:7 Issue: 3, Summer 2018

Journal of Dental Materials and Techniques
Volume:7 Issue: 3, Summer 2018

  • تاریخ انتشار: 1397/04/16
  • تعداد عناوین: 8
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  • Poonam Kulkarni *, Rahul S. Kulkarni, Rupal J. Shah, Anup Vyas Pages 105-110
    Introduction
    Prosthodontic management of palatal defects has been employed for many years. Palatal defects of any extent cause multiple problems in speech, mastication and aesthetics. Obturator prosthesis for an edentulous patient is more critical in terms of its movements as there is no mechanical retention available. Obturators and facial prostheses are important not only for rehabilitation and aesthetics, but also in patient resocialisation. Maxillary defects are created by surgical treatments of benign or malignant neoplasms and by trauma, in which case, denture is supported only by the underlying residual ridge and the defect. This clinical report describes the rehabilitation of a maxillary resected patient with a single piece hollow bulb denture obturator fabricated by double investment technique.
    Materials and Methods
    In this double investment technique of hollow bulb denture obturator fabrication two same size transposable flasks were used for flasking and curing of the prosthesis.
    Results
    Hollow bulb denture obturator was obtained by this double investment technique.
    Conclusion
    Decreased weight of prosthesis positively affects retention leading to improved physiologic function, and it also does not cause excessive atrophy in muscle balance.
    Keywords: Double investment, Single piece, Hollow bulb obturator
  • Fatemeh Mazhari, Elham Fakhar Izadi, Farzaneh Barani Karbasaki * Pages 111-116
    Introduction
    Many different kinds of chewing gum can increase the flow of saliva, and they have been proven to have anti-bacterial effects as well. The aim of this study was to compare the effect of natural turpentine and synthetic sugar-free gums on dental plaque pH after a sucrose challenge.
    Methods
    This randomized clinical trial was conducted on 15 subjects, who refrained from oral hygiene for two days and rinsed with 10% sucrose solution. Then for 30 minutes, they chewed one of three sugar-free gums: Van (natural), Orbit Complete, Orbit (synthetic), or one sugar-containing chewing gum (Banana). One group did not receive any gum (control group). Plaque pH was measured by the plaque sampling method before rinsing with sucrose, and 5, 10, 15, 20, and 30 minutes after chewing.
    Results
    The lowest plaque pH drop was seen in the Orbit Complete group, and the highest was in the Banana group. The pH increased faster with Van and Orbit Complete gums. The plaque pH was more than baseline pH after 20 minutes in the Van and Orbit Complete groups (P
    Conclusion
    All the three sugar-free gums were effective, although the pH recovery was higher and faster in the Van and Orbit complete groups.
    Keywords: dental plaque pH, natural turpentine, synthetic sugar-free gum
  • Fahimeh Rashidi Maybodi, Mehrdad Jalali Pandary, Elahe Karami, Ali Reza Ebrahimi * Pages 117-122
    Statement of the Problem: Anxiety is one of the most common factors hindering people from visiting dentists. Therefore, finding a solution for stress control has been a significant issue in recent studies. It seems that music positively affects inhibition of psychological stress. Other studies have shown that aroma may adjust perception, patience and moods.
    Purpose
    This study investigated the effect of music and lavender’s aroma on blood pressure, heart rate and anxiety.
    Materials And Method
    Ninety patients were divided into three groups. At the beginning, patients were asked to complete Spielberger’s questionnaire to assess the level of anxiety. Blood pressure and heart rate were also measured. In the first group, surgery was performed, while the patient smelled the fragrance of lavender; in the second group, surgery was accompanied by playing a relaxing music and in the third group, no intervention was done. Then, patients were again requested to complete the questionnaire and their blood pressure and heart rate were again measured.
    Results
    In the control group, no statistically or clinically significant difference was observed in systolic and diastolic blood pressure or heart rate. In the aroma therapy and music groups, systolic and diastolic blood pressure values didn’t change clinically but heart rates were decreased. In the control and music groups, anxiety levels didn’t change significantly but in the aroma therapy group, anxiety had a significant decrease.
    Conclusion
    Using aroma and relaxing music, regardless of whether it affects or not on anxiety, aroused pleasant feelings in patients.
    Keywords: Anxiety, Periodontal Treatment, Music, Aroma
  • Farshad Bajoghli, Ehsan Ghasemi *, Saeed Sahafi Pages 123-128
    Background
    Different soldering techniques have a variety of applications in dentistry. One of the most important uses of soldering is to join multiple-unit fixed partial dentures together. In this Study, two base metal alloys (Supercast and Minalux) were soldered and their tensile, compressive and flexural strengths were measured and compared to each other.
    Materials And Methods
    In this in-vitro study, an aluminum pattern was made by a milling machine according to ASTM (American Society for Testing Material). Eighteen acrylic resin Patterns were duplicated by flasking using putty indices according to the original aluminum pattern. Acrylic resin patterns were divided into two groups of nine and each group was cast with two different alloys named Supercast and Minalux. All eighteen metal rods were separated by 0.008-inch disc and soldered with Vera-solder by means of gas-oxygen torch. Three patterns of each alloy were selected for each of the compression, tensile and flexural tests. Tensile strength was measured by Instron a universal machine and flexural and compression strengths were measured by Dartec machine. Statistical analysis was done by Mann - Whitney test.
    Results
    The mean tensile, flexural and compressive strengths for supercast alloy was 347.6, 44.01 and 1014.8MPa respectively and the mean for tensile, flexural and compressive strengths for Minalux alloy was 350.03, 51.70 and 938.17 MPa respectively. Statistical analysis showed no significant differences between the two alloys in all the three mentioned tests. (p>0.05)
    Conclusion
    Tensile, flexural and compressive strengths of the two soldered alloys, Minalux and supercast, showed no significant differences. Minalux is an alloy manufactured in Iran with the advantage of not including Beryllium, a cariogenic element, as one of the ingredients of the alloy; therefore, it is suggested that Minalux be used instead of supercast in soldering procedures in fixed prosthodontics.
    Keywords: Alloy, Minalux, Soldering, Solder joint, super cast
  • Armita Rouhani, Fateme Zoormand Ghasemi, Majid Akbari, Shima Mosivand* Pages 129-134
    Introduction
    After endodontic procedures, root canal reinfection is a main concern for dentists. However, application of a proper apical seal can prevent such contamination. Therefore, it seems necessary to study the factors affecting the development of a suitable apical seal.
    Materials And Methods
    In this study, 64 extracted human single-canal premolars were used. An equal length of roots was obtained by cutting the crown. The teeth were randomly divided into four experimental groups of 15 premolars, as well as 2 positive and negative controls. The root canal was manually prepared using K-file and step back method through canal filling by lateral compaction technique. In GP and GH groups, gutta-percha and AH 26 sealer were used to fill the canals, while Resilon and Epiphany sealer were used in RP and RH groups, respectively. Then, to prepare the post space, Peeso Reamer drill was used in GP and RP groups while heat carrier was applied in GH and RH groups to prepare the post space, respectively. The coronal part of each root was contacted with enterococcus faecalis leachate in BHI medium and the root end was placed in the same culture medium. The samples were daily checked for turbidity in the lower culture medium for 90 days. The average duration of bacterial leakage between the groups wascompared using independent Student t-test.
    Results
    All the positive control samples showed bacterial infiltration within 24 to 48 hours, while the negative control teeth remained uninfected during the test. Comparison of bacterial leakage rates between GP and GH groups showed no significant difference, which was similar to comparison results between RP and RH groups (P=0.549 and P=0.097, respectively). Comparison of bacterial leakage between GP and RP groups, as well as between GH and RH groups, showed a significant difference (P=0.018 and P
    Conclusion
    Considering the results of this study, the use of gutta-percha as a root filling material results in a better apical seal than Resilon. Application of heat carrier and Peeso Reamer showed no significant difference in effectiveness on the apical seal.
    Keywords: Apical Seal, Gutta-percha, Resilon, Bacterial Leakage
  • Ehsan Ghasemi *, Mansour Rismanchian, Navid Haghayegh Pages 135-140
    Statement of the Problem: For a successful clinical outcome, luting agents should have a high bond strength. Bond failure is still one of the main reasons of restoration failures.
    Purpose
    The present study was designed to comparatively evaluate the retention of metallic copings using different resin luting cements.
    Materials And Method
    In the present experimental study, 40 intact premolar teeth were included. The teeth were prepared to receive copings with a chamfer bur at high speed, cooled with an air/water spray. The occlusal surface was prepared flat, perpendicular to the long axis of the root at a standardized height of 4 mm from the gingival chamfer finish line with a 20 degree consistent taper of axial walls. The wax patterns were prepared and cast. Teeth with un-cemented casts were randomly divided into 4 groups based on the type of cement used. The tensile load required to dislodge the crowns was measured using Instron universal testing machine with a crosshead speed of 1mm/min. The data were analyzed by SPSS software and Kruskal-wallis test (a=0.05).
    Results
    The maximum and minimum amounts of crown retention were in Panavia-F2 and Maxcem cements respectively. Despite this different retention values in cements, Kruskal-wallis disclosed no significant difference between groups in the mean amount of crown retention. (P-Value=0.068)
    Conclusion
    Regarding the results of the study, it was concluded that there are no mentionable differences between all groups.
    Keywords: Cementation, Dental Cements, Retention, tensile strength
  • Soudabeh Sargolzaei, Saede Atarbashi-Moghadam *, Farzad Aghdashi, Sara Mansouri Nejad Pages 141-144
    Adenomatoid odontogenic tumor is a non-aggressive slow growing epithelial odontogenic tumor with varied clinical and microscopic features. This neoplasm rarely appears as a completely cystic lesion histopathologically; therefore, oral pathologists should be aware of the various histopathologic types of this lesion. The main objective of this case report is to present a rare challenging case of maxillary extrafollicular cystic adenomatoid odontogenic tumor affecting a 28-year-old male.
    Keywords: odontogenic tumor, maxilla, benign, cyst, adenomatoid odontogenic tumor
  • Mahin Bakhshi, Fatemeh Mashhadi Abbas, Kosar Rezaei Far * Pages 145-148
    Hemangioma, which is a rife benign proliferative lesion with vascular tissue origin, is the most common vascular anomaly of infancy. Cellular hemangioma is one type of these tumors, known as the vascular channel formation of endothelial cells. This report describes a 34-year old man with an exophytic lesion on the lower lip , firm, dome shape ,smooth surface with mild keratosis who came to us two months ago ; histopathologic finding showed a relatively rare subtype of hemangioma, cellular hemangioma ,which characterized by the potential for recurrence and cellular immaturity . Among hemangioma subtypes, the most common are cavernous and capillary hemangiomas; a relatively rare subtype is cellular hemangioma, characterized by the potential for recurrence and cellular immaturity. CH most commonly involved parotid gland, but may also occur internally in the oral mucosa in infancy and early childhood. Mmucocele and pyogenic granuloma were considered in the differential diagnosis for our case.
    Keywords: Hemangioma, Cellular hemangioma, lip