Showing 28 results for Arami
Masumeh Hasani Tabatabaei, Sakine Arami, Ayob Pahlavan, Esmaeil Yasini, Mansoure Mirzae, Hamid Kermanshah, Farnaz Farahat,
Volume 26, Issue 1 (3-2013)
Abstract
Background and Aims: To evaluate the effect of polishing on surface roughness of silorane-based composite using profilometery and Scanning Election Microscopy (SEM) and compare it with that of a methylmethacrylate-based composite and a glass ionomer.
Materials and Methods: In this study, 3 groups (n=28) were tested: specimens of two composites (Filtek P90 and Filtek P60) and a glass ionomer (Fuji IX) which were prepared in polyethylene molds (4 mm diameter×10 mm height). Half of the specimens in each group were finished with 180-grit silicon carbide paper and the remaining were finished with 180-grit, and subsequently polished with 250, 400, 800, 1000, 2000, and 2500-grit silicon carbide papers. The surface roughness was evaluated using a contact profilometer and then mean (Ra) and maximum (Rmax) of surface roughness were recorded. Then, the surface of 4 specimens of each subgroup was observed under SEM. Statistical analysis was performed with T-test, ANOVA and Dunnett T3 tests.
Results: In all materials, Ra was different between polishing with 180 and 2500-grit silicon carbide papers. In 180-grit group, only Ra of Filtek P60 and Fuji IX showed significant difference (P=0.01). In 2500-grit group, there was no significant difference between the Ra of Filtek P60 and Filtek P90 (P=0.56).
Conclusion: Polishing is recommended for the glass ionomer and posterior composite restorations.
Ayob Pahlavan, Masumeh Hasani Tabatabaei, Sakineh Arami, Mohammad Ataie, Sara Valizadeh,
Volume 26, Issue 1 (3-2013)
Abstract
Background and Aims: Polymerization shrinkage in Methacrylate-based composite is one of the most important factors in composite restorations failure. Silorane-based composite is introduced to compensate this drawback and claimed to have low shrinkage. The aim of this study was to evaluate the polymerization shrinkage of these two composites.
Materials and Methods: In this experimental study, 5 disk shape samples for each resin composites were placed in the centre of metallic ring bonded to microscopic glass slab. Top surface of ring was covered by a glass cover slip. Glass slab and sample were placed on a special LVDT holder in order to light cure from bottom surface and to measure the polymerization shrinkage. In this study, Deflecting Disk method and LVDT (linear variable differential transducer) was used for dimensional change measurement of resin composites. In this study, two LED curing units were used for composite polymerization.
Results: The mean of polymerization shrinkage in Z250 cured with LED and High Power LED was 11.15±0.08µm and 11.51±0.17µm, respectively (P=0.094), and in P90 cured with LED and High Power LED was 1.08±0.06µm and 1.16±0.12µm, respectively (P=0.019).
Conclusion: Silorane-based composite (P90) showed significantly less polymerization shrinkage than that of methacrylate-based composite (Z250). For the two types of composite, there was no significant difference between the two curing units in polymerization shrinkage.
Arami Sakineh , Aghasadeghi Mohamadreza , Tabatabaie Masome Hasani , Darvishpour Hojat , Sheikhzadeh Sedigheh ,
Volume 27, Issue 4 (1-2015)
Abstract
Background and Aims: Hepatitis B is an important infection route in dentistry requiring different disinfectants to prevent its transmission. The aim of this study was to compare the effects of chemical disinfectants (FD366, ISORAPID and 5% sodium hypochlorite 2/100) to remove Hepatitis B infections from the dental surfaces.
Materials and Methods: In this experimental laboratory trial, serum of 10 HBV patients was poured into microtubes, FD366, ISORAPID and hypochlorite disinfectants were added to them. PCR experiments with viral diagnostic kits were used to diagnose the virus genome. Real time PCR was used to evaluate after incubation with the disinfectants. The reductions occurred in the viral load of Hepatitis B were statistically analyzed using Kruskal-wallis and Mann-Whitney U tests .
Results: No significant antiviral efficacy was noted following the application of FD366 and ISORAPID disinfectants (P=0/07). However, hypochlorite showed the most efficacy to disinfect Hepatitis B and a significant difference was found among them (P<0.0001).
Conclusion: Under the study limitations, FD366 and ISORAPID disinfectants did not show adequate efficacy to remove Hepatitis B virus. Hypochlorite was the most effective disinfectant.
Masumeh Hasani Tabatabaei, Sakineh Arami, Fatemeh Khajavi, Zohreh Moradi,
Volume 29, Issue 4 (1-2017)
Abstract
Background and Aims: Despite the reduction of incidence of dental caries in recent years, this disease is common and many efforts were conducted to decrease the prevalence of dental caries. On the other hand secondary caries lesions are the main reason for replacement of direct restorations. Therefore, the aim of the current study was to evaluate suitable methods of preparation and restorative materials to reduce caries recurrence.
Materials and Methods: In this experimental study, eighty human teeth were collected and stored in normal saline. The teeth were soft-tissue debrided and cleaned with water/pumice slurry and rubber cups in a low-speed handpiece. Speciments were randomly divided in two main groups. Cavities were prepared with diamond burs or Er:YAG laser (10 Hz, 300 mJ, 3W). Each group was divided into 4 sub-groups, and restored with a glass-ionomer cement (Fuji IX), resin modified glass-ionomer (Fuji II LC), total etch bonding + composite resin or self-etch bonding + composite resin. The specimens were submitted to pH cycling. Speciments were then sectioned, polished and Vickers microhardness measurements were performed on each specimen. Differences among the medians were analyzed using two way ANOVA test at a 95% confidence level and Tukey test.
Results: Statistical analysis showed significant difference in the type of substrate (enamel, dentin) in both main groups (P<0.0001) but no differences in the caries lesion development between the cavities restored with the same material and prepared with diamond burs or Er:YAG laser.
Conclusion: The Er:YAG laser used for cavity preparation and different types of restorative materials used did not show the ability to guarantee significantly more acid-resistance tooth structure against demineralization.
, Manoochehr Karami, Ghodrattollah Roshanaei, Abbas Shokri, Namdar Pasandi,
Volume 29, Issue 4 (1-2017)
Abstract
Background and Aims: Acurate measurements of variables are crucial in epidemiological studies. Therefore, even the best design cannot prevent bugs caused due to the lack of reliability and validity measurement in studies. The aim of this study is to determine the validity of teeth-canal measurement.
Materials and Methods: This methodological study used available data of patients referred to dental clinics at Hamadan University of Medical Sciences in Hamadan with sample size or 58 cases in 2012. In order to determine the reliability of measuring the length of canals and introduce the most appropriate measure met of the actual data, Bland-Altman plot and intraclass correlation coefficient (ICC) were used and finally compared.
Results: In this study, the mean ± SD of channel length in the apex locator Root ZX were 21.93 ± 2.28 mm and in X-ray PA were 22.4 ± 2.38 mm. ICC between the length of canals by the apex locator and radiographic in all teeth was 0.989. Bland-Altman plot showed that absolute agreement between the two methods of measurement.
Conclusion: The findings of this study ensure dental professionals that measuring the length of channels by PA method is more practical and easier and prove different approaches of the reliability and validity. However, we recommend using ICC and Bland Altman methods due to their informative nature and consideration of absolute agreement instead of consistency.
Sakineh Arami, Sakineh Arami, Masoumeh Hasani Tabatabaei, Seyed Reza Najafzadeh, Ahmadreza Shamshiri, Zohreh Moradi,
Volume 30, Issue 4 (1-2018)
Abstract
Background and Aims: According to many uses of MTA in different treatments, studying about its properties like the setting time, is of great importance. The aim of this study was to compare the initial and final setting time of an Iranian MTA and a foreign MTA.
Materials and Methods: Seven samples were in each group; for measurement of initial and final setting time of MTAs, a mold with dimension of 2×10 mm was prepared. The cements after mixation were put into an incubator with temperature of 37ₒC and humidity of 90%. After mixing of cements, a Gilmore needle with a weight of 100 gr and active tip of 2 mm was used vertically on the surface of MTA for measurement of the initial setting time. Setting was measured by the start of cement mixation to the time the tip of the needle didn’t penetrate to the surface of MTA. For measurement of the final setting time a Gilmore needle with a weight of 456 gr and active tip of 1mm was used vertically on the surface of MTA. The ANOVA test followed by Tukey test was used for comparison of the mean setting time between an Iranian and foreign MTA. The statistical difference was considered significant at the level of 0.05.
Resultes: The mean initial setting time Angelus and Root MTAs were 13.57±0.91 and 11.14±0.92 min, the mean final setting of Angelus and Root MTA, were 48.93±1.54 and 37.86±1.5 min while the initial setting time of Angelus MTA lasted for 0.53±43.2 more min than Root MTA (P=0.001). The final setting time of Angelus MTA took longer for 110.7±0.82 min than Root MTA (P=0.001).
Conclusion: The initial and final setting time of the Iranian MTA was shorter than the foreign one and thus it could a more alternative option in this respect.
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.
Azadeh Zakerzadeh, Abdolrahim Davari, Haleh Karami,
Volume 33, Issue 2 (8-2020)
Abstract
Background and Aims: The self-adhering composites were introduced to reduce the chair time and minimizing handling errors. They can be bonded micromechanically to the dental structure without the need for separate adhesive application. Since there is limited information about bonding performance of this type of composite, the aim of this study was to evaluate the microleakage of enamel and dentin margins compared to the conventional adhesive systems.
Materials and Methods: 30 intact premolars were selected and on their buccal and lingual surfaces, standardized class V cavities with the occlusal margin in enamel and gingival margin in dentin were prepared. Then according to the materials used, the specimens were randomly divided into three groups including: 1) Vertise flow, 2) SE bond + ValuxTM Plus, and 3) Single bond + ValuxTM Plus. After final polishing of the restorations, the specimens were subjected to 1000 thermal cycles of 5±2 and 55±2°C and after that dye penetration was examined by stereomicroscope. The collected data were statistically analyzed using Kruskal-Wallis test and Mann-Whitney test
Results: The lowest rate of the occlosal microleakage was related to group 2 (P<0.05) and there was no significant difference between groups 1and 3 (P=0.58). Also, no significant difference was found in the gingival microleakage among the three groups (P=0.23). On the other hand, in each group, the gingival microleakage was significantly higher than occlosal margins (P<0.05).
Conclusion: According to the results, sealing ability of self-adhering composite is comparable with that of the conventional adhesives.
