Showing 32 results for Kazemi
Mohamad Reza Khalili, Babak Ziaie, Mahmoud Kazemi,
Volume 26, Issue 4 (1-2014)
Abstract
Background and Aims: Dental implants have been studied for replacement of missing teeth for many years. Productivity of implants is extremely related to the stability and resistance under applied loads and the minimum stress in jaw bone. The purpose of this study was to study numerically the 3D model of implant under thermal loads.
Materials and Methods: Bone and the ITI implant were modeled in “Solidworks” software. To obtain the exact model, the bone was assumed as a linear orthotropic material. The implant system, including implant, abutment, framework and crown were modeled and located in the bone. After importing the model in Abaqus software, the material properties and boundary conditions and loads were applied and after meshing, the model was analyzed. In this analysis, the loads were applied in two steps. In the first step, the mechanical load was applied as tightening torque to the abutment and the abutment was tightened in the implant with 35 N.cm torque. In the second step, the thermal load originated from drinking cold and hot water was applied as thermal flux on the ceramic crown surface in this model.
Results: Thermal analysis results showed that the thermal gradient in the bone was about 5.5 and 4.9 degrees of centigrade in the case of drinking cold and hot water respectively , although the maximum gradient of the whole system was reduced to 14 degrees, which occurred, in the crown by drinking cold water.
Conclusion Thermal stresses were so small and it was because of the low thermal gradient. Maximum stresses occurred in the abutment were due to the tension preloads which were originated from the tightening torque.
Mahmod Kazemi, Saeed Nokar, Ahmad Rohanian, Adel Pazhohan,
Volume 26, Issue 4 (1-2014)
Abstract
Background and Aims: Thermal changes in the oral cavity can be transferred to the implants placed in bone and affect the prognosis of the treatments. Furthermore, some investigators proposed improvement of habitual consumption of hot or cold beverages. The aim of the present study was to measure the effect of temperature changes in the oral cavity following consumption of hot and cold drinks on the temperature of implant.
Materials and Methods: In this clinical trial, 3 eligible patients were selected. Two months after implant insertion, temperature of the implants was measured following the drinking of hot and cold beverages using a sensor connected to a thermometer. The thermal changes of the implants through the different time intervals were analyzed using Friedman non-parametric test.
Results: The implant temperatures were significantly increased in the time following drinking of the hot beverages (P=0.009). Furthermore, the implant temperature were statistically decreased in the time after drinking cold beverage (P=0.004). When drinking hot beverages, the maximum and minimum temperatures were 41.57 0 C and 36.77 0 C, respectively. The maximum and minimum temperatures of the implants were also 34.13 0 C and 26.83 0 C , respectively, when drinking cold beverages.
Conclusion: It seems that the temperatures noted in the implants in the current study cannot weaken the prognosis of implant restorations however, habitual consumption of hot and cold beverages can lead to debilitating implant prognosis and therefore, should be given the necessary warnings to patients.
Davari Abdolrahim , Daneshkazemi Alireza , Modaber Maryam , Malekzadeh Mohammad ,
Volume 27, Issue 4 (1-2015)
Abstract
Background and Aims: The most effective preventing tooth decay method is fluoride compounds applications. Some studies suggested that APF gels caused changes on the superficial physical properties of composite. Therefore, the purpose of this study was to evaluate the marginal microleakage of class V composite restorations before and after AFP gel application.
Materials and Methods: The class V cavities in buccal surfaces of 45 molar teeth were made in such a way that occlusal margin was placed in enamel and cervical margin in cement. In group 1, at first fluoride-therapy and then cavity preparation and restoration by composite resin was done. In group 2, at first the class V cavities were prepared and restored, then fluoride-therapy was carried out. In group 3, cavities were prepared and restored with no fluoride-therapy. The dye penetration rate in occlusal and cervical margins was examined by stereomicroscope. Data were statistically analyzed using Kruskal-Wallis and Mann-Whitney test.
Results: There was no statistically significant difference between groups ( P=0.975).
Conclusion: Fluoride-therapy using AFP gel before and after class V composite restorations, had no significant effect on the microleakage of dentin and enamel margins.
Mehryari Mahsa , Mortazavi Nazanin , Sayyadi Fatemeh , Mohsenitavakoli Saman , Zahedpasha Shaghayegh , Mortazaviamiri Seyedhadi , Bijani Ali , Kazemi Hamed Hossein , Motallebnejad Mina ,
Volume 27, Issue 4 (1-2015)
Abstract
Background and Aims: The purpose of the present study was to review the studies regarding serological and salivary oxidant / antioxidant status in patients with recurrent aphthous stomatitis (RAS).
Materials and Methods: The literature was searched using key words RAS, Antioxidants, Saliva, Hematinic (s) and Hematinic Acid in the last 10 years, particularly the recent 3 years (2010-2013). At total of 37 clinical trials, 18 case-control articles were selected and evaluated fulfilling the requirements as the RAS patients having at least 3 oral aphthous attack per year. The exclusion criteria included systemic as well as periodontal diseases, iron deficiency associated anemia, medication usage and smoking.
Conclusion: Almost all lipid-peroxidation studies in serum and saliva were manifested by an increase of malondialdehyde (MDA) concentration in RAS patients compared with controls. This would indicate the role of reactive oxygen species (ROS) in the etiology of the disease. Serum trace elements (Zn, Se) were reduced and Cu was increased in RAS patients in comparison with control individuals. A decreased serum superoxide dismutase (SOD) and an increased salivary SOD were observed in all RAS patients. Catalase (CAT) and uric acid (UA) analyses were non-inclusive. Levels of paraoxonase and arylesterase as well as antioxidant vitamins (A, E, C) were lower in RAS patients than that of controls.
Mahmod Kazemi, Alireza Pornasrollah, Somayeh Allahyari, Hamid Jalali,
Volume 28, Issue 2 (7-2015)
Abstract
Background and Aims: Adequate retention has significant importance in the prognosis of implant supported cemented the restorations. Limited literature had evaluated the effect of direct wax up or use of plastic coping on the retention of these restorations. This aims of this study was to compare the retention of castings fabricated by the plastic coping and direct wax up for single crown and bridge in three implant systems.
Materials and Methods: 28 specimens of each implant systems were randomly divided into 4 groups. Groups included wax patterns for single crowns and bridges that were made from plastic coping or direct wax up. All the wax patterns were invested and casted with base metal alloy, in similar conditions. After castings were cemented to the related abutments, the specimens were subjected to a pull out force in a universal testing machine at a cross head speed of 0.5 mm/min. The load required to decement each casting was recorded and the mean values for each group were calculated. Data were analyzed using three-way ANOVA.
Results: Comparing the between systems in crowns fabricated from plastic coping, there was no significant difference between Replace and Implantium (P=0.124), but ITI had significantly lower values than that of other systems (P<0.001 Comparing the systems in crowns fabricated from direct wax up, Implantium had the greatest retention and ITI had the lowest retention (P<0/001). Comparing the bridges with both method, Replace had the greatest retention and ITI had the lowest retention.
Conclusion: Implantium and Replace system exhibited the highest retention for fabricating crowns, and bridges, respectively.
Abdolrahim Davari, Soghra Yassaei, Alireza Daneshkazemi, Mohadeseh Khosravanian,
Volume 28, Issue 2 (7-2015)
Abstract
Background and Aims: Orthodontic bracket failure during treatment is a common problem. With the introduction of low shrinkage composites the question is that whether: this sufficient has coefficient bond strength for bonding bracket during orthodontic treatment. The aim of this study was to compare the shear bond strength (SBS) of silorane-based and metacrylate-based composites to metal brackets.
Materials and Methods: 30 human premolar teeth were collected and divided into 2 groups. In group 1, 15 orthodontic brackets were bonded using silorane-based composite, in group 2, 15 orthodontic brackets were bonded using metacrylate-based composite. The shear bond strength of each specimen was determined in an Instron machine. Amount of residual adhesive remaining on each tooth was evaluated using a stereomicroscope. Data were analyzed using T-test to compare the shear bond strength between groups and LSD method to compare the Adhesive Remnant Index (ARI) scores.
Results: There was significant difference in the SBS between the test groups (P<0.001). The mean bond strength of bonding brackets to silorane-based composite was (42.42 ± 7.03) MPa, and the mean bond strength of bonding brackets metacrylate-based composite was (21.08±2.97 ) MPa. No significant difference in the ART was found between groups (P=0.66).
Conclusion: Silorane-based composite provided higher bond strength to orthodontic metal brackets.
Alireza Daneshkazemi, Abdolrahim Davari, Farnaz Farahat, Neda Pazhoohi,
Volume 28, Issue 2 (7-2015)
Abstract
Background and Aims: The purpose of this study was to compare the effect of chlorhexidine 2%, ethanol 70% and sodium ascorbate 10% and delayed bonding for 1 week on the shear bond strength of composite resin to enamel after bleaching.
Materials and Methods: 90 human central incisors were divided into 6 equal groups: Group 1: no bleaching Group 2: bleaching with carbamide peroxide 45% for 45 minutes Group 3: bleaching + restoring specimens in distilled water for 1 week. In group 4, 5 and 6, after bleaching, 1 cc of chlorhexidine 2%, ethanol 70% and sodium ascorbate 10% were applied for 15 minutes. Composite cylinders were bonded on the buccal surfaces. Specimens were thermocycled for 1000 cycles and the shear bond strength test was done. Specimens were examined under stereomicroscope and SEM. Data were analyzed a sign ANOVA and Bonferroni test.
Results: The shear bond strength values were not significantly lower in the bleached teeth (group 3, 4, 5 and 6) than that of negative control group (group 1) (P=1.000, P=0.069, P=0.081, P=1.000) Bonferroni test results show significant difference between test groups (3, 4, 5 and 6) and group 2 (P<1.000, P=0.007, P=0.008, P<1.000) Under SEM, resin tags in group 2 was thinner and lesser than group 3, 4, 5 and 6. The most adhesive failures were in group 2.
Conclusion: Bleaching with carbamide peroxide and immediate bonding of composite decreased the shear bond strength. Sodium ascorbate 10% and delayed bonding for 1 week were the most effective way.
Abdolrahim Davari, Alireza Danesh Kazemi, Mehrrnaz Fallah Tafti,
Volume 30, Issue 4 (1-2018)
Abstract
Background and Aims: A suitable restorative material must have acceptable mechanical properties. The aim of this study was to evaluate the effect of conventional acidic drinks on the micro-hardness of two dental resins.
Materials and Methods: 48 samples of each of P60 and G-aenial composites were prepared and randomly divided into six groups: Coca-Cola, Fanta, yoghurt drinks, soft beer, Sprites and control groups. The study was in 3 steps: after one day in distilled water and after one day and one week of immersion in beverages per day
(6 hours). The Vickers micro-hardness was then evaluated. Finally, data were analyzed by, t-tests, ANOVA and Tukey tests.
Resultes: Comparing the results between the two groups, a significant difference between the two composite was found. After one day in the water, the average micro-hardness for P60 was of 27.12 (kgf/mm2) and 16.51 (kgf/mm2) for G-aenial amount and these differences were found statistically significant (P=0.0001). For the
6-hour maintenance interval, the average micro-hardness between P60 and G-aenial was statistically significant (P=0.0001). For 42 hours, the average micro-hardness ranged between P60 and G-aenial that were statistically significant (P=0.0004). The stiffness of the P60 composite after 42 hours’ storage in soft beer significantly decreased compared with the control group (P=0.03). G-aenial composite hardness after 42 hours of soaking in the Coca-Cola was reduced significantly compared to yogurt drinks (P=0.02).
Conclusion: As a result, the hardness of P60 composite was higher than that of G-aenial. The hardness of both composites reduced in acidic drinks after one week.
Hamid Bakhshi, Narges Sadat Mirjalili, Zeinab Kazemizadeh, Foad Iranmanesh, Elham Reisi Estabragh,
Volume 31, Issue 1 (6-2018)
Abstract
Background and Aims: Despite their ascribed intellectual ability and achieved academic pursuits, the dental student’s academic achievement is influenced by learning motivation. This study in an Endeavour aimed to examine the learning motivation factors of dental students of Rafsanjan University of Medical Sciences.
Materials and Methods: In this descriptive-cross sectional study, 120 dental students completed the questionnaire which comprised of 33 questions regarding intrinsic and exogenic motivational factors. Demographic factors (gender, marital and native status, employment year of study) were examined. Data were analyzed by SPSS17 software. Descriptive and analytical statistical methods (t-test, Pearson correlation and ANOVA statistical tests) were used.
Results: The mean of the achieved scores in the domains of learning motivation was 2.98±0.32 out of 5,which was considered as moderate level. Comparing the means of the intrinsic (3.16±0.48) and exogenic
(2.82±0.44) domains showed significant differences (P<0.05). Correlation between the intrinsic motivation domain and elements of exogenic motivation domain with academic achievement were not significant (P=0.62). Total score of Intrinsic and exogenic motivation is higher in male and non-native students.
Conclusion: Educational motivation of Rafsanjan dental students was moderate. In learning, intrinsic motivational factor was more than exogenic factors in male students.
Rahelesadat Mirseifi Nejad Naini, Alireza Daneshkazemi, Fahime Shafiee,
Volume 31, Issue 2 (9-2018)
Abstract
Background and Aims: Increased tooth sensitivity is a common dental problem. One of the mechanisms of dentin hypersensitivity treatment is blocking dentinal tubules. The aim of this study was to compare the average closing dentinal tubules affected by carbonated Nano-hydroxyapatite and fluoride toothpaste using scanning electron microscope (SEM).
Materials and Methods: The enamel of gingival buccal crown surfaces of 42 sound maxillary premolars teeth were removed until the dentin surfaces were exposed. The dentine specimens of 3×3 mm were prepared. The specimens were washed by distilled water after etching and randomly divided into 6 groups. 3 groups were interfered with the carbonated nano-hydroxyapatite toothpaste and the other three groups interfered with Colgate toothpaste in 3, 7 and 14 days. The samples were examined by SEM to check the status of dentinal tubules. Then, they were evaluated by two researchers according to the Hulsmann index. Data were analyzed by using SPSS23 software and Kruskal-Wallis statistical test. The significance level of 0.05 was considered.
Results: The amount of dentinal tubules closure by the two toothpastes was significantly different. This difference was higher in the hydroxyapatite toothpaste than fluoride which were (P=0.024, 0.004 and 0.000), respectively. There were no significant differences among the groups in 3,7 and 14 days (P=0.230, 0.069, 0.537).
Conclusion: The toothpaste containing carbonated nano structural hydroxyapatite was more successful in closing dentinal tubules than Colgate toothpaste in short period of time.
Abdolrahim Davari, Alireza Daneshkazemi, Farnaz Frahat, Fatemeh Kohestani,
Volume 32, Issue 1 (7-2019)
Abstract
Background and Aims: Despite patient’s demand increased for tooth color restorations, the stable bond between dentin and composite is a challenge in dentistry. Dentin protease activation is responsible for dentin-resin bond failure. The aim of this study was to determine the best pretreatment agent to inhibit matrix metalloproteinase and increase resin-dentin bond durability.
Materials and Methods: After collecting 24 intact third molars, the dentin surfaces were exposed immediately under DEJ. After acid etching of dentin rewetting was done with CHX 2%, EDC 0.3 M for 60 and water (control group). Then the adhesive (Single bond, 3M ESPE, USA) and composite (Filtek Z250 XT, 3M ESPE, USA) were applied. 48 sectioned dentinal specimens were prepared. The specimens were divided into 3 groups. Each group was divided into 2 sub groups (n=8). In half of each group, the micro tensile bond strength test was done immediately and another part half 6 months. Then, the specimens were evaluated by stereomicroscope and SEM. Statistical analysis was performed using SPSS23 software, two-way ANOVA and multiple Tukey and T-test comparisons. P<0.05 was considered as a significant level.
Results: There were not significant differences between immediate micro tensile bond strength of CHX, EDC and control groups (P=0.97). However, there was significant differences between CHX, EDC compared with the control group (P≤0.0001). Comparison between the immediate and 6-month bond strengths in each group, only in EDC group, there was no significant after 6 months’ difference (P=0.64).
Conclusion: EDC and CHX t did not have any effect on the immediate microtensile bond strength. After 6 months, EDC prevented bond strength deterioration, but the bond strength was decreased after CHX usage.
Abdolrahim Davari, Alireza Daneshkazemi, Mahsan Sheshmani, Haleh Karami, Elham Motallebi,
Volume 32, Issue 3 (11-2019)
Abstract
Background and Aims: The bleaching agents can lead to color and translucency changes in composite resins. Due to the increasing use of the nano composites and the silorane-based composites, this study aimed at examining the color and translucency changes of these restorations after bleaching agents.
Materials and Methods: In this experimental - laboratory study, 198 composite discs were divided into three groups of 66 specimens using three types of composite: the microhybrid composite Z250, the nanohybrid composite Z350 and the silorane-based composite P90. After acid etching, half of the specimens in each group were covered by a resin rebounding agent. Then, the color and translucency assessment was done by reflectance spectrophotometer, using CIE LAB system. Each group was divided into three subgroups of bleaching agents: the 40% hydrogen peroxide and 20% carbamide peroxide bleaching agents and the control group. After applying bleaching agents, the final color and translucency changes were assessed. Data were analyzed using Mann Whitney and Kruskal Wallis tests.
Results: The effect of composite and bleaching agent type and bonding agent were significant (P<0.001). The color changes in the microhybrid composite were higher than nanohybrid and silorane-based composites (P<0.001) (∆E>3.3). Also, the color changes by 20% carbamide peroxide were higher than that of hydrogen peroxide and control groups (P<0.001). The results of translucency changes were generally consistent with color-change measurements (∆E>3.3).
Conclusion: According to the present study, the most color changes appeared in the microhybrid composite and by 20% carbamide peroxide bleaching agent. Rebound samples were generally less affected by bleaching agents. The least color and translucency changes were related to nanohybrid composites.
Alireza Daneshkazemi, Abdolrahim Davari, Motahareh Amiri, Fatemeh Mirhosseini,
Volume 33, Issue 1 (7-2020)
Abstract
Background and Aims: Erosion is the chemical dissolution of a tooth by acid without bacterial involvement. The purpose of the current study was to investigate the effect of resin infiltration (Icon), MI paste plus, and Nd:YAG laser on the enamel microhardness.
Materials and Methods: 40 enamel samples were obtained from the third molar tooth. Primary microhardness was measured in all specimens. Then, erosion was created using hydrochloride acid on the surfaces of enamel and the microhardness values were measured. The samples were randomly divided into four groups. G1: MI paste plus, G2: MI paste plus+ Nd:YA laser, G3: ICON without etching, G4: ICON with etching. Erosion was induced again by hydrochloric acid and then subjected to thermocycling. Finally, the microhardness of the samples was measured. Statistical analysis was performed using SPSS23 software, one-way ANOVA, multiple Tukey and T-test comparisons. P<0.05 was considered as a significant level.
Results: The microhardness increased in the third stage compared to the second stage in all groups, which was statistically significant (P<0.000). Also, the comparison of the increase of microhardness among groups, except second group with the fourth group, was statistically significant.
Conclusion: All the materials used in this study significantly increased the microhardness of the eroded enamel.
Mozhgan Kazemian, Saleh Dadmehr,
Volume 33, Issue 1 (7-2020)
Abstract
Background and Aims: Some of the post-operative complications of impacted third molar surgery, one of the most prevalent surgeries in oral field, are known to be infection, erythema, trismus and pain. Antibiotic prescription to prevent post-operative infection under some particular circumstances, is acceptable but under debate considering their disadvantages. In the present study, we examined the infection rate in patients taking no or 2 types of antibiotics distinctively after impacted mandibular third molar surgery.
Materials and Methods: In this double blind clinical trial, 90 patients within the age range of 18 to 34 were dedicated to 3 groups (group 1: 2 capsules of placebo on surgery day and 1 for 4 days, group 2: Amoxicillin 500 mg every 8 hours for 5 days, group 3: Azithromycin 250 mg, 2 capsules on surgery day and 1 capsule for 4 days). All subjects were treated by a sole surgeon, protocol, surgical technique, and flap type and the same amount of osteotomy. In addition to aforesaid drugs, the patients received chlorhexidine and Gelofen 400 mg. At the day 7 postoperative, cases were examined to evaluate the infection (trismus, erythema and halitosis). Data were analysed using Chi-Square test and the groups were compared by Kruskal-Wallis test.
Results: Three signs of infection (halitosis, erythema and trismus) were compared in patients. Symptoms of halitosis and erythema were more indicated in first group, but the ultimate statistical analyses among the 3 groups from halitosis and erythema viewpoint showed no significant difference (P=0.072, P=0.149). Although, no severe trismus was reported, the most moderate trismus incidence was in group 2 and mild trismus was exhibited in group 1. In group 3, no trismus occurred. On the whole, the trismus frequency among groups was statistically significant (P=0.004).
Conclusion: Comparing infection symptoms of the three study groups emphasized the fact that only trismus rate was statistically significant (P=0.004). On balance, the results of this study indicated that antibiotics did not have significant impact on the reduction of most postoperative complications, especially on infection.
Alireza Daneshkazemi, Abdolrahim Davari, Zahra Usefi, Niloofar Fallah, Solmaz Ghanbarnejad, Pedram Daneshkazemi,
Volume 33, Issue 3 (10-2020)
Abstract
Background and Aims: Adding nanoparticles to dental composite resins, could reduce bacterial adhesion and secondary caries. Thermocycling can resemble in-vitro conditions to the oral environment. The aim of this study was to determine the effect of thermocycling on the microleakage of a mixture of copper oxide nanoparticles and flowable composite.
Materials and Methods: In this in-vitro study, 88 premolar teeth were divided into eight groups based on the application of copper oxide nanoparticles with concentrations of 0.1% and 0.3% w/w and thermocycling by 0, 1000, 5000 and 15,000 cycles. The occlusal grooves of the teeth were sealed with the mixture of flowable composite and copper oxide nanoparticles, and the teeth were thermocycled. Next, the teeth were immersed in methylene blue 2% solution for 24 hrs and were cut and the microleakage was evaluated by a stereomicroscope (hp/USA). Data were analyzed using Kruskal-Wallis and Mann-Whitney tests at the significance level of 0.05.
Results: In the groups with 0.1 % copper oxide nanoparticles, the mean microleakage increased significantly with increasing the number of thermocycling rounds (P=0.032). The difference in the microleakage between the groups exposed to 0 and 15,000 termocycling was significant (P=0.019). However, thermocycling had no significant effect on the microleakage of groups with concentration of 0.3% (P=0.780). The specimens subjected to the 0, 1000, 5000 and 15000 thermocycling in two concentrations of copper oxide nanoparticles showed no significant difference in the microleakage.
Conclusion: In groups containing copper oxide nanoparticles with a concentration of 0.1%, the microleakage increased by increasing the number of thermocycling up to 15,000 cycles compared to the control group. However, this did not have significant effect for the concentration of 0.3% copper oxide nanoparticles.
Alireza Omrani, Pedram Daneshkazemi, Amir Mansour Shirani, Mohammad Amin Habibi,
Volume 34, Issue 0 (5-2021)
Abstract
Background and Aims: Temporomandibular joint disorders (TMDs) are one of the most common causes of the patient's referral to dental clinics. Considering the role of related factors in its creation, the purpose of this study was to investigate the relative frequency of factors related to temporomandibular disorders in patients aged 20 to 50 years referred to dental clinics in Isfahan in 1397.
Materials and Methods: In this descriptive and analytical study, 324 patients referred to Isfahan dental clinics in 1397 were randomly included. Factors related to TMD and demographic factors of patients were recorded with clinical examination by a trained dentist and self-declaration of patients in the data collection form. The frequency and relevance were analysed by SPSS 22 software and chi-square, fisher and logistic regression statistic tests.
Results: At least one of the TMD related factors was present in 40.7% of the subjects, which the most common factors related to TMD was posterior edentulousness (49.7%). History of jaw dislocation was more common in men (P=0.014) and the frequency of posterior edentulousness was more common in in women (P=0.003). As the age increased, the frequency of posterior edentulousness (P=0.000) and earache (P=0.009) increased. The frequency of posterior edentulousness was higher in housekeepers (P=0.000), the frequency of earache was higher in employees (P=0.005) and the history of jaw dislocation was higher in self-employed persons (P=0.047). |
Conclusion: The high prevalence of TMD and related factors, such as a history of jaw dislocation, posterior edentulousness, earache, and clenching, requires attention to be identified and treat these problems.
Fatemeh Kazemi Bidhendi, Mahshid Mohammadi Basir, Doctor Mohammad Bagher Rezvani, Doctor Ali Khodabakhsh, Hossein Labbaf, Mohammad Amin Fahimi,
Volume 35, Issue 0 (5-2022)
Abstract
Background and Aims: Finishing and polishing of composites is a critical step influencing the clinical service of restorations. The aim of this article was to evaluate and compare the effect of two liquid polishes on the polish retention of two nanocomposites.
Materials and Methods: Eighty standardized disk-shaped specimens (4×2 mm) were prepared from two nanocomposites (n=40), including one nano-filled composite (Filtek Z350 XT-3M ESPE, USA) and one nano-hybrid composite (Aelite Aesthetic Enamel-Bisco, Inc. Schaumburg, USA). The specimens were randomly divided into 4 subgroups (n=10) based on the method of finishing (F) and polishing (P) procedures: M: as control, polymerized under Mylar strip; S: finish and polish with a sequence of Sof-Lex discs (3M ESPE, USA); SP: finish and polish with Sof-Lex discs and use of Permaseal liquid polish (Ultradent products, Inc. USA); SB: finish and polish with Sof-Lex discs and use of Biscover liquid polish (Bisco, Inc. Schaumburg, USA). The specimens were undergone pH cycling and brushing machine and then, the average surface roughness (Ra) and average profile changes along the desired area (Rz) of the specimens were determined with profilometer instrument. Two-way and one-way analysis of variance (ANOVA) was used to compare the mean of surface roughness. Then, Tukey test was used to identify the groups responsible for the difference and t-test was used to compare the mean of surface roughness.
Results: The type of composite and the method of polishing procedure had no effect on the mean Ra (P=0.733) but it had significant effect on Rz1 factor (P=0.025).
Conclusion: Using liquid polish after polishing discs had no effect on the polish retention of nanocomposites.
Elya Ranayi, Fatemeh Rahmatzadeh Yousefabadi, Saber Babazadeh, Ali Kazemian,
Volume 35, Issue 0 (5-2022)
Abstract
Background and Aims: The aim of this study was development and validation of a questionnaire measuring the pseudo-scientific unsupported of Iranians’ belief regarding oral health.
Materials and Methods: A list of 169 pseudo-scientific and invalid Iranian beliefs about oral health that was collected in the previous phase of the study were sent to a purposive sample of 13 professors at Mashhad dental school which resulted in extracting 34 beliefs being considered more common among Iranians. A list of 21 pseudo-scientific beliefs was obtained for preparing the questionnaire after receiving the sample opinions of 21 professors of Mashhad dental school about the invalidity and pseudoscientific propositions and their written revision. Finally, the questionnaire was completed by 44 participants to analyze the ease and clarity and to calculate Cronbach's alpha and Kuder Richardson measure as a homogeneity reliability index. It was completed in a group of 15 participants with a time interval of one month for test-retest analysis and consistency reliability evaluation.
Results: A questionnaire consisting of 21 beliefs was developed using four-point, three-point, or two-point Likert scales. The standardized Cronbach's alpha score and Kuder Richardson's measure score were 0.641 and 0.514, respectively, which indicated the moderate to good reliability of the homogeneity. The Interclass Correlation Coefficient (ICC) was calculated as 0.863, representing very good reliability of consistency of the questionnaire. Furthermore, the kappa coefficient of each of the 21 statements had a significant difference with zero (P<0.05) ranging between 0.605 and 1.
Conclusion: The result of the present study is a questionnaire measuring the level of Iranians’ belief in unsupported and invalid statements about oral health. Using this questionnaire would be helpful for dentists and oral health professionals to promote knowledge of Iranians about oral health.
Bahareh Tahani , Zahra Kazemi Zahrani,
Volume 35, Issue 0 (5-2022)
Abstract
Background and Aims: With the growth of elderly population, attention to their oral health status has become increasingly important. Most of the available studies have been conducted among dependent elders who usually have different oral health statuses and needs. Therefore, the aim of this study was to determine the oral health status of independent elderly attending municipal public centers and parks in Isfahan in 2020.
Materials and Methods: This is a descriptive-analytical cross-sectional study conducted among 195 elderly people attending Isfahan municipal centers in 2020. The oral health status and the oral health related quality of life (QOL) of elderly were evaluated using Geriatric Oral Health Assessment Index (GOHAI) and clinical examinations. The obtained data were analyzed using descriptive statistics (mean and standard deviation), correlation, independent T-test, Chi-squared and ANOVA using SPSS22 (α=0.05).
Results: 69% of the participants (n=133) were male and the mean age was 68.9± 3.5. Almost 20% of elderly (n=39) did not have any of their natural teeth. 63% (n=123) suffered from at least two chronic diseases and 38.5% (n=75) had a functional occlusion. The mean score of quality of life (QOL) of elderly and their DMFT was 51.7±6.4 and 20.5±6.3, respectively. A significant and negative relationship was found between the DMFT and GOHAI (P<0.001, r=-0.36). QOL scores were significantly higher in participants with dentures than those without dentures (P<0.001). There was a significant relationship between the frequency of brushing and the mean of DMFT (P<0.001). In people who did not brush, the DMFT score was higher than those who brushed at least once a day or even sometimes a week.
Conclusion: The results indicated that the oral health status of elderly was weak and it would reflect the need for more attention to taking more measures to both prevent the oral problems and to promote oral health.
Mohammad Fazeli, Masomeh Ahmadi, Parisa Asadollahi, Hossein Seyedkhani, Elahe Karimi, Liela Ghitani, Nahid Mahdian, Dr Hossein Kazemian,
Volume 36, Issue 0 (5-2023)
Abstract
| Background and Aims: Root canal treatment failures are often attributed to incomplete removal of bacteria, particularly Enterococcus faecalis. While, chlorhexidine and sodium hypochlorite serve as conventional treatments. herbal medicine has been today considered as an alternative to synthetic medicine due to its safety. Therefore, the aim of the present study was to compare the antibactrial effect of Scrophularia Striata extract with chlorhexidine and sodium hypochlorite on Enterococcus Faecalis in the tooth root canal.
Materials and Methods: In this study, sixty extracted teeth were examined. Following the infection of dental canals with Enterococcus faecalis, materials were tested in 3 groups: 1) chlorhexidine 2% (18 teeth), 2) sodium hypochlorite 2.5% (18 teeth), and 3) Scrophularia striata (at the concentration obtained from MIC, 20%; 18 teeth). Additionally, the positive control and negative control were included (3 teeth in each group). Samples were then cultured on bile esculin agar. After 72 hours, black colonies were eaxamined. Chi-squared test was used to analyze the results.
Results: Enterococcus faecalis bacteria grew in 6, 8, and 17 out of the 18 teeth within the sodium hypochlorite, chlorhexidine, and Scrophularia striata extract groups, respectively. Consequently, the bactericidal effects for sodium hypochlorite, chlorhexidine, and Scrophularia striata extract were 66.6%, 55.5%, and 5.55%, respectively. |
Conclusion: The antibacterial effect of the Scrophularia striata extract was significantly lower than chlorhexidine and sodium hypochlorite on Enterococcus faecalis in dental canals viewed as a suitable replacement to the already in use synthetic therapeutic irrigants.
