Mashhad University of Medical SciencesJournal of Dental Materials and Techniques2322-41506320170901Effect of Storage Media and Sterilization Method on Shear Bond Strength of Composite to Enamel of Extracted Teeth96102901210.22038/jdmt.2017.9012ENAlireza BoruziniatDental Materials Research Center, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, IranNasrin Danaifardgeneral dentistMahshid GifaniPost-graduate student, Department of Pediatric Dentistry, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, IranNarjes HakimiPost-graduate student, Department of Operative Dentistry, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, IranJournal Article20170410<strong>Aim</strong>: To evaluate the effect of storage media and autoclaving on shear bond strength of composite to enamel<strong>. Materials and Methods:</strong> 100 human premolars were randomly divided into ten groups of ten as follows: C: freshly extracted teeth. A: Autoclaved freshly extracted teeth. CH-6: 6 month storage in 0.5 % chloramine T. CA-6: 6 month storage in 0.5 % chloramine T + autoclaving. T-6: 6 month storage in 0.04 % thymol. TA-6: 6 month storage in 0.4% thymol + autoclaving. Ch-12:12 month storage in 0.5 % chloramine T. CA-12: 12 month storage in 0.5 % chloramine T + autoclaving. T-12: 12 month storage in 0.4% thymol. TA-12:12 month storage in 0.4% thymol + autoclaving. One composite cylinder was bonded on each specimen for evaluation of shear bond strength (SBS) and failure modes. Data were analyzed using three-way ANOVA, Tukey’s post hoc and Chi square tests and the level of significance was set at P= 0.05.<br /> <strong>Results:</strong> Autoclaving and storage media had no significant effect on SBS (P-value = 0.818 for storage media and P-value = 0.221 for autoclaving). However, storage duration significantly changed SBS (P-value = 0.00). There were no correlations among the variables (P-value > 0.05). Storage media and duration had no significant effect on failure modes (P-value > 0.05), but autoclaving significantly increased cohesive failure of enamel (P-value =0.039).<strong> Conclusion:</strong> Storage of teeth in chloramine T and thymol had no significant effect on bond strength to enamel. Although autoclaving of specimens may not alter bond strength, it can significantly increase the cohesive failure of enamel.<br /> <br /> Mashhad University of Medical SciencesJournal of Dental Materials and Techniques2322-41506320170901A New Hybrid Technique for Beading and Boxing of Complete Denture Final Impressions103107893710.22038/jdmt.2017.8937ENPoonam R KulkarniAssistant Professor, Department of Prosthodontics, Sri Aurobindo College of Dentistry, Indore, IndiaRahul S KulkarniAssistant Professor, Department of Prosthodontics, Index Institute of Dental Sciences, Indore, IndiaSumeet JainProfessor, Department of Prosthodontics, Sri Aurobindo College of Dentistry and PG Institute, Indore, IndiaJournal Article20170327<strong>Introduction:</strong> The purpose of beading & boxing of an impression is to obtain an accurate cast with proper border & base thickness for fabrication of restorations. Beading is the protection of the formed border thickness of the final impressions & Boxing of an impression is building up vertical walls around it.<strong> Aim: </strong>The purpose of this hybrid technique of beading and boxing is to produce a smooth & aesthetically acceptable cast with accurate border thickness using a simple procedure.<strong> Materials & Methods:</strong> In this hybrid technique of beading and boxing an impression, a uniform layer of modeling wax was applied over the beading of a plaster-pumice mixture around an impression; after that, boxing & pouring of an impression was done to retrieve a cast.<strong> Results:</strong> Casts obtained by hybrid technique was more accurate in border thickness & more aesthetic in comparison to the cast obtained by wax technique of beading & boxing.<br /> <strong>Conclusion:</strong> Beading and boxing of an impression is done to protect the formed border thickness of an impression, regulate the height & size of the cast, avoid undue trimming of the cast and to eliminate distortion associated with slumping of the gypsum material when an impression is inverted. This hybrid technique of beading and boxing eliminates the need for applying separating media over the beading of a plaster-pumice mixture and by this technique retrieval of the cast from the impression is very easy and quick. The resulted cast will be very neat and clean with accurate thickness of the borders and base of the cast .This technique is suitable for impressions made from almost any type of impression material.Mashhad University of Medical SciencesJournal of Dental Materials and Techniques2322-41506320170901The Effect of Lithium Disilicate Ceramic Thickness and Translucency on Shear Bond Strength of Light-cured Resin Cement108116893810.22038/jdmt.2017.8938ENMohammad Javad MoghaddasDepartment of Restorative and Cosmetic Dentistry, School of dentistry, Mashhad University of Medical Sciences, Mashhad, IranHamideh Sadat MohammadipourDental Materials Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
Department of Restorative and Cosmetic Dentistry, School of dentistry, Mashhad University of Medical Sciences, Mashhad, IranRoya Amiri DaluyiDental Materials Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
Department of Restorative and Cosmetic Dentistry, School of dentistry, Mashhad University of Medical Sciences, Mashhad, IranAzin Jahan NiaStudent of dentistry, Mashhhad University of Medical Science, school of dentistry, Mashhhad,IranJournal Article20170504<strong>Introduction:</strong> To achieve acceptable clinical performance, a ceramic veneer must be bonded to enamel by well-polymerized resin cement. Among different factors, thickness and translucency of the ceramic may affect the resin cement polymerization. Thus, the current study evaluated the effect of the thickness and translucency of lithium disilicate ceramic on light-cured resin cement bond strength to enamel.<strong> Methods:</strong> In this laboratory study, 208 sound bovine incisors were equally divided into 16 groups (n = 13). The lithium disilicate ceramic cubes in four thicknesses (0.4, 0.6, 0.8 and 1 mm) with four translucencies (high and medium opaque, high and low translucent) were fabricated and bonded to prepared enamel surfaces using a light-cured translucent resin cement according to manufacturer recommendations. After 5000 cycles of thermocycling, the bonded specimens were placed in a universal testing machine and loaded to the point of fracture. To determine the mode of failure, each sample was observed under a stereomicroscope. Data were recorded and analyzed by Shapiro-Wilk test and two-way analysis of variance (ANOVA).<strong> Results</strong>: The ceramic thickness and translucency could not significantly affect shear bond strength (SBS) of resin cement to enamel (<em>p</em> = 0.17 and <em>p</em> = 0.097, respectively). The Adhesive and ceramic cohesive failures were reported as the maximum and minimum mode of failure, respectively. <strong>Conclusion:</strong> The SBS of the light-cured resin cement bonding to enamel and lithium disilicate ceramic was not affected by the translucency of ceramics having a thickness of less than 1 mm.<br /> <br /> Mashhad University of Medical SciencesJournal of Dental Materials and Techniques2322-41506320170901Assessment of the Effect of Fruit (Apple) and Plain Yoghurt Consumption on Plaque pH117124893910.22038/jdmt.2017.8939ENPayvand MoeinyAssistant Professor, Department of Pediatric Dentistry, School of Dentistry, Islamic Azad University, Tehran Branch, Tehran, IranSahar SayahpourPostgraduate Student, Department of Pediatric Dentistry, School of Dentistry, Islamic Azad University, Tehran Branch, Tehran, IranFarhad RaofieAssistant Professor, Department of Chemistry, Shahid Beheshti University of Sciences, Tehran, IranAlireza AminikhahDentistMohamad Javad KharazifardResearch Member, Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, IranJournal Article20170516<strong>Introduction:</strong> Nowadays, thanks to improvements in fruit yoghurt tastes, more tendencies are seen in their consumption especially among children. Therefore, their cariogenicity evaluation as healthy snacks is important. The goal of this study was the assessment of the consumption effect of two kinds of Iranian fruit (apple) and plain yoghurts on dental plaque PH. <strong>Methods:</strong> In this experimental study, 10 healthy dentistry students were selected upon inclusion criteria. Plaque pH in the certain areas of the mouth was measured by microelectrode and digital pH meter. PH was measured at the baseline and intervals of 2, 5, 7, 10, 15, 20, 30, 40, 50 and 60 minutes after eating test products: fruit yoghurt (apple) and plain Yoghurt. For positive control group, just the baseline PH and at intervals of 2 and 5 min after swishing with 10% sucrose solutions were recorded. The results were analyzed using repeated measures ANOVA.<strong> Results:</strong> Lowest pH was obtained after fruit yoghurt consumption followed by plain yoghurt and %10 sucrose solution and the plaque PH difference was significant (P=0.05). Furthermore, time duration which remained below the critical pH was longer after consuming fruit yoghurt. <strong>Conclusion:</strong> Both kinds of yoghurts were considered cariogenic since plaque pH drop below critical points. Average of plaque pH after consuming fruit yoghurt was significantly lower in almost all the time intervalsMashhad University of Medical SciencesJournal of Dental Materials and Techniques2322-41506320170901Effect of Tannic Acid Application on Durability of Bond of Etch and Rinse Adhesive Resins125130901410.22038/jdmt.2017.9014ENAlireza BoruziniatDental Research Center, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, IranMostafa BabazadehGeneral dentistMahshid GifaniPost-graduate student, Department of Pediatric Dentistry, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, IranMonavar NasirzadehPost-graduate student, Department of Operative Dentistry, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, IranJournal Article20170404<strong>Aim:</strong> To determine the effect of different concentrations and application times of tannic acid on bond strength to dentin.<strong> Materials and Methods:</strong> Occlusal surfaces of 180 human molars were randomly divided into two groups of immediate shear bond strength evaluation and evaluation after 2 months of storage in collagenase solution. Each group was divided into 10 subgroups according to the solutions applied: no additional treatment (control), chlorhexidine 2% (Positive control), tannic acid 20% (30s, 1 min, 3min, 5min) and Tannic acid 30% (30s, 1 min, 3 min, 5 min). Failure mode were assessed using a stereo-microscope. The data were statistically analyzed by One-way ANONA and Tukey<sup>’</sup>s post hoc test. <strong>Results:</strong> There was no significant difference in immediate bond strength among experimental groups. However, after 2 months storage in collagenase solution, a significant difference was found among the groups. Bond strengths of CHX and 20% TA applied for 3 minute were significantly higher than the control group.<strong> Conclusion:</strong> Use of tannic acid and chlorhexidine has no negative effect on immediate shear bond strength. However, their application significantly prevents compromised bond strength caused by storage in collagenase solution.<br /> <br /> Mashhad University of Medical SciencesJournal of Dental Materials and Techniques2322-41506320170901Prevalence of Impacted Teeth among Young Adults: A Retrospective Radiographic Study131137894010.22038/jdmt.2017.8940ENHamidreza ArabionDepartment of Oral and Maxillofacial Surgery, School of Dentistry, Shiraz University of Medical Science, Shiraz, IranMahdi GholamiOral & Maxillofacial Disease Research Center, Mashhad University of Medical Science, Mashhad, Iran
Department of Oral and Maxillofacial Surgery, School of Dentistry, Mashhad University of Medical Science, Mashhad, IranHabibollah DehghanDentist, Private PracticeHussein KhalifeOral and Maxillofacial Surgeon, Private Practice, Beirut, LebanonJournal Article20170508<strong>Objectives:</strong> The prevalence of impacted teeth fluctuates across various ethnicities and geographical regions. The aim of the present study was to evaluate the prevalence and patterns of impacted teeth among patients living in the central part of Iran. <strong>Methods</strong>: This retrospective study was conducted on 3632 patients within the age group of 17-30 years. The frequency and pattern of the impaction were determined using orthopantomogram (OPG). <strong>Results:</strong> According to the results of the study, 56.3% of the patients were female (n=2046). Out of the 3632 OPGs, 1602 cases (44.1%) were detected with at least one impacted tooth. No significant difference was observed between the males (n=682; 42.6%) and females (n=920; 57.4%) in this regard (P=0.237). Furthermore, the third molars were the most common impacted teeth found in 1156 radiographs (31.8%) with no significant difference between the males (n=358; 30%) and females (n=798; 70%) (P=0.386). Mesioangular and distoangular impactions were detected to be the most frequent angulation of the impacted third molars in the mandible (49%) and maxilla (41%), respectively. Additionally, 357 (9.8%) and 78 (2.1%) cases showed at least one impacted maxillary canine and one impacted mandibular second premolar, respectively. Moreover, impacted ectopic teeth were observed in 11 (0.3%) individuals. <strong>Conclusion:</strong> Based on the findings of the present study, the third molar was the most common impacted tooth observed in the people living in the central region of Iran, followed by canine and second premolar impaction. The prevalence of the third molar impaction in the females was nearly twice as much as that in the males.Mashhad University of Medical SciencesJournal of Dental Materials and Techniques2322-41506320170901A Case Report of Multifocal Epithelial Hyperplasia (Heck's Disease) Treated with CO2 Laser138141899210.22038/jdmt.2017.8992ENJavad SarabadaniOral and Maxillofacial Disease Research Center, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran0000-0002-6269-7777Sahar HeydariSchool of dentistry, Mashhad University of medical sciences, Mashhad, IranAmirreza MashreghiDepartment of Orthodontics, School of dentistry, Mashhad University of Medical Sciences, Mashhad, IranNiloofar PoornazariSchool of dentistry, Mashhad University of medical sciences, Mashhad, IranJournal Article20170709Focal epithelial hyperplasia or Heck’s disease is a rare benign lesion of oral mucosa caused by human papilloma virus especially subtypes 13 and 32. The disease is predominantly found in children and adolescents with indigenous heritage. This paper reports a unique case of Heck's disease in an 11-year-old Iranian girl with multiple, bilateral and elevated lesions on the buccal and labial mucosa. The lesions had persisted for a year. The disease was diagnosed as focal epithelial hyperplasia through the clinical examination. Considering esthetic and functional problems, CO<sub>2 </sub>laser (Wavelength: 10600 nm) surgery was determined as a suitable choice of treatment. The patient was followed up over 1 year with no signs of lesion recurrence.Mashhad University of Medical SciencesJournal of Dental Materials and Techniques2322-41506320170901Autotransplantation of a mandibular third molar: A case report142146894110.22038/jdmt.2017.8941ENElham NajafiPostgraduate Student of Endodontics, Mashhad University of Medical Sciences, Mashhad, IranHamid JafarzadehAssociate Professor, Department of Endodontics, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran0000-0001-5318-7129Mahsa DastpakPostgraduate Student of Endodontics, Mashhad University of Medical Sciences, Mashhad, IranJournal Article20170411Tooth autotransplantation defines as transition of one tooth from one position to another, in same individual. It is a biological procedure in which teeth have the potential to induce alveolar bone growth. It can be applied in patients before adolescence growth is finished. It significantly reduces time and cost compared to implants. Healing rapidly occurs and function is regained almost immediately. Our case was a 15-year-old male that his left mandibular third molar transplanted to the second molar sight after extraction of second molar because of unrestorable crown. During 9 month follow up transplanted tooth was asymptomatic, functional and responsive to sensibility tests. (Cold test, EPT).