Showing 21 results for Yasini
E. Yasini,
Volume 1, Issue 1 (9 1987)
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AR-SA Class-Ionomer cements include calcium
aluminosilicate glass and fluid component of acrylic acid. An important property of these cements is
chemical adhesion to enamel and dentin and releasing anti-caries fluride.
Clinical use of these cements involves filling erosions without cavity
preparation, preventive dentistry and filling class V and llI cavities. In
addition, another desirable property of these cements is their biocompatibility
with tissues and dental pulp.
E. Yasini , M. Eslami , E. Aleksanian , M. Mohamadi Basir ,
Volume 5, Issue 1 (9 1992)
Abstract
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AR-SA In 9 patients of 11-20 years old, Pulp response
to phosphoric acid 37% during a 15 seconds etching period was studied. Class V
cavities in cervical third of premolars were prepared as symmetrical couples.
All the process was identical in both groups of case and control. In test
group, 15 seconds etching period by phosphoric acid 37% was done. The teeth
were then restored by ZOE. Only one case complained of pain and discomfort.
After 1,2,4,6,12,24,56 days the teeth were extracted. In 100 sections made from
extracted teeth of 5 patients , pulpal response to acid reaction was a mild
inflammation with good prognosis.
E. Yasini , Gh. Rahbari , A. Matorian ,
Volume 7, Issue 1 (8 1994)
Abstract
Today laser has a lot of usage in medicine and dentistry. In the field of dentistry, laser is used in soft tissue surgery, sterilization of canals (in root canal therapy) and in restorative dentistry laser is used for cavity preparation, caries removal, sealing the grooves (in preventive dentistry), etching enamel and dentin, composite polymerization and removal of tooth sensitivity. The use of Co2 lasers and Nd: YAG for cavity preparation, due to creating high heat causes darkness and cracks around the region of laser radiation. Also due to high temperature of these lasers, pulp damage is inevitable. So today, by using the Excimer laser especially the argon floride type with a wavelength of 193 nm, the problem of heat stress have been solved, but the use of lasers in dentistry, especially for cavity preparation needs more researches and evaluations.
E. Yasini ,
Volume 9, Issue 2 (9 1996)
Abstract
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AR-SA Mercury has been used in amalgam restorations
for more than a century though it is poisonous and mercury vapor can endanger
the health of patients and dental office staff. Therefore, they should be aware
of its hazards and observe guidelines to prevent injury to nervous system,
heart, kidneys, alimentary and respiratory systems. The source of mercury
poisoning in dental offices can be of stored mercury, evaporation while mixing,
inserting, condensing, carving, burnishing or polishing the amalgam , amalgam residuals,
poisoning while replacing old amalgam restorations or while steriling the
instruments. In any case, we can state that although the amount of mercury
released from amalgam compared to the mercury in the environment is negligible
but the dental staff who work with mercury should observe the safety
guidelines.
E. Yasini , N. Mohammadi ,
Volume 12, Issue 3 (10 1999)
Abstract
Polymerization contraction may produce defects in the composite - tooth bond. This may lead to bond failure and microleakage. The aim of this study was to reduce microleakage of posterior composites using different methods. 45 molar and premolars extracted teeth were choosen. The cavities were randomly assigned into 5 groups of 9. Box-shaped cavities were prepared on each side of proximal surfaces and restored by five different methods. Group 1 was filled by a light-cured composite and dentin bonding agents (DBAs) with light curing from the occlusal area. Group 2 was filled by a light-cured {LC} composite and DBA, in addition the angle between the light source and occlusal area was 45 degree. After conditioning of teeth in-group 3, LC glass ionomer was placed on the gingival floor and then filled by a light-cured composite and DBA. In group 4, after conditioning, the teeth were lined by a LC glass ionomer and then self-cured composite was placed on gingival floor. This group was filled with LC composite. In Group 5 DBA was used followed by placing a self-curing composite on gingival floor and filled by LC composite. The teeth were subjected to 500 thermocycling (5°C and 55°C with dowel time 30 s) and stored in 0.5% basic fushin for 24 hours. Dye penetration was evaluated by light microscope. The results were tested by Kruskat-Wallis one-way analysis of variance by rank. The comparison between treatment groups showed highly significant difference {P<0.0001). No significant difference was found between groups 3 versus 4 and groups 1,2,5 versus 3,4. Group 3 showed the least microleakage score. Therefore least microleakage was obtained by the group which used L C glass ionomer and DBA followed by filling a composite.
E. Yasini , N Mohammadi ,
Volume 14, Issue 4 (10 2002)
Abstract
Posterior composite restorations, due to polymerization contraction, result in microleakage. Different methods have presented to reduce this phenomena. The aim of this study is to evaluate the effects of flowable and condensable composites to reduce microleakage. Seventy extracted human teeth were prepared with proximal class II cavities with gingival margin 1 mm below CEJ. The teeth randomly were divided into 7 groups. Groups I & II were restored with a dentin bonding (DB) agent plus a Prodigy condensable (Kerr Co.) composite, placing incremental or bulky, respectively.. In groups IK IV, V a dentin bonding agent was applied and then cavities were restored with Tetric flow composite resin as a base plus either a hybrid composite (Tetric ceram, Vivadent Co.) or a Prodigy condensable composite (Cond), placing bulky or incremental. Groups VI and VII were restored with a resin modified glass ionomer (GI) (Fuji II Lc Co.) as a base plus either Prodigy condensable or Tetric ceram. Restorations were polished, thermocycled, and immersed in 0.3% basic fushin. After that samples were sectioned and studied under a stereomicroscope to evaluate dye penetration. Results showed that all restorations showed some degree of microleakage and according to kruskall- wallis statistical analysis, there were not any significant differences between all groups (P-0.051). Then fore pair comparison, between groups. Mann-Whitney analysis was used and no statistical difference was observed. However. Gh DB- Tetric group showed the least microleakage and DB+ Cond (bulk) the most one. Due to lack of an" statistical difference among different materials methods, it is concluded that no method or restorative material have been able to eliminate microleakage in margins completely yet, and using a flowable composite resin, in place of resin modified glass ionomer or using a condensable composite, instead of conventional In brid composites, do not have any effect
E. Yasini , Mb. rezvani ,
Volume 15, Issue 1 (25 2002)
Abstract
Ultrasonic scaling of class V composite or glass Ionomer restorations may cause destructive effects. The purpose of this study is to investigate the effects of ultrasonic scaling on the marginal leakage of composite and Glass Ionomer restorations. An in-vitro study was performed on thirty- two upper and lower premolar teeth, free of any kind of caries, cracks or facets. Class V cavities, with the depth of 1.5 mm and the height and width of 2 mm, were prepared on the buccal and lingual surfaces. Occlusal margin and cervical margin were placed entirely in enamel and cementurn, receptively. Thirty-two cavities were restored with composite resin (Z100) (3M Co.), while the other thirty- two cavities were restored with Glass Ionomer cement (Vitremer) (3M Co.) and were bonded with Scotch Bond Multipurpose Plus (SBMP) (3M Co.). Half of each group were thermocycled, then half of each thermocyled and non-thermocycled groups were selected randomly for ultrasonic scaling test. After scaling, all teeth surfaces were coated with two layers of nail varnish up to 1mm of restoration. Samples were immersed in 0.5% fushin solution for 24 hours and were vertically sectioned by a diamond disk. Regarding dye penetration and microleakage, samples were examined by a stereobinoclar microscope. The results were analyzed by Mann-Whitney and Kruskal Wallis (a=0.05). They indicated that degree of microleakage in the composite/ enamel, with thermocycling and ultrasonic scaling were less than Glass Ionomer samples. Although in cervical margin, at the beginning, composite leakage was significantly less than Glass Ionomer cement, but thermocycling and ultrasonic scaling and their combination increased it and had a meaningful difference with Glass Ionomer.
E. Yasini , M. Pour Kazemi ,
Volume 17, Issue 4 (7 2005)
Abstract
Statement of Problem: The pulp may be exposed during remove of caries or by traumatic and iatrogenic injuries. The material used to DPC, must be biocompatible, scalable and prevent bacterial leakage.Furthermore, it is better to stimulate dentinogenesis. Calcium hydroxide is most usual material for DPC. But it cannot provide a suitablcbiologic seal. Mineral irioxide aggregate (MTA) is also a suitable material for DPC.
Purpose: The aim of this study was to compare the clinical success of DPC done with MTA or calcium hydroxide cement.
Materials and Methods: In this study eighteen posterior teeth without previous spontaneous pain that involved mechanicaly exposure was randomly selected and capped with MTA or calcium hydroxide. These teeth were evaluated by clinical vitality test and radiograph after 3 and 12 months, and patients were questioned about irritative or spontancus pain in this period. Statistical analysis was carried out by Usher exact
test (a-0.05).
Results: This study showed that in calcium hydroxid groud three had irreversible pulpitis and two teeth had symptom and signs of reversible pulpitis. While, In MTA group all cases were normaL and no clinical sign was evident.
Conclusion: MTA exhibited better results than calcium hydroxide cement for the capping of the pulp in human
E. Yasini , E. Malekan ,
Volume 18, Issue 1 (30 2005)
Abstract
Statement of Problem: The use of dentine bondings on enamel and dentin in total etch protocols has recently become popular. Unfilled resin is hydrophobic and dentin bonding is hydrophilic in nature. This chemical difference could be effective in enamel bonding process. Purpose: The aim of this study was to compare the shear bond strength of unfilled resin to dry enamel and dentin bonding to dry and moist enamel.
Materials and Methods: In this experimental study, a total of 30 incisor teeth were used. The specimens were randomly assigned to three groups of 10. 37% phosphoric acid etchant was applied to the enamel surfaces in each group for 15 seconds, rinsed with water for 20 seconds and dried for 20 seconds with compressed air in groups one and two. After conditioning, group 1 received unfilled resin (Margin Bond, Colten) and group 2 received dentin bonding (Single Bond, 3M) and in group 3 after conditioning and rinsing with water, a layer of dentin bonding (Single Bond) was applied on wet enamel. The enamel and dentin bonding were light cured for 20 seconds. A ring mold 3.5 mm in diameter and 2 mm height was placed over the specimens to receive the composite filling material (Z100, 3M). The composite was cured for 40 seconds. The specimens were thermocycled and shear bond strengths were determined using an Instron Universal Testing Machine. The findings were analyzed by ANOVA One-Way and Tukey HSD tests.
Results: Shear bond strength of dentin bonding to dry enamel was significantly less than unfilled resin to dry enamel (P<0.05). There was no significant difference between the bond strength of dentin bonding to moist and dry enamel. In addition bond strength of dentin bonding to wet enamel was not significantly different from unfilled resin to dry enamel.
Conclusion: Based on the findings of this study, it is suggested that enamel surface should remain slightly moist after etching before bonding with single bond but when using unfilled resin, the enamel surface should be kept dry.
E. Yasini , M. Ataei , M. Amini ,
Volume 18, Issue 2 (4 2005)
Abstract
Statement of Problem: The relatively poor wear resistance of dental composite in stress bearing posterior situations has restricted wider clinical application of this restorative material.
Purpose: The aim of this study was to evaluate the three body abrasive wear of a dental composite based on a new filler (leucite: KAl Si2O6) and to compare it with the wear resistance of a composite based on commonly used Aluminium – Barium Silicate filler.
Materials and Methods: This research was an interventional study done in Iran polymer institute. Five specimens were considered in each group. All ceramic IPS Empress® (Ivoclar- Vivadent) ingots based on leucite crystals were ball milled, passed through an 800 sieve and used as filler. Experimental composites were prepared by mixing the silane- treated fillers with monomers (BisGMA and TEGDMA). Camphorquinone and amine were used as photoinitiator system. Degree of conversion of the light-cured and post-cured composites was measured using FTIR spectroscopy. The prepared pastes were inserted into plexy-glass mold and light cured (700 mw/cm2, 40 s). Then for maximum degree of conversion specimens were post- cured (120ºC, 5 hours). Three body abrasion wear testing was performed using a wear machine with 50 rpm rotational movement. In this machine, pumice (150 meshes) was used as the third body. Weight loss of specimens in each group was measured by balance after each 50 hours. After wear testing SEM examination was made specimens in each group. The data were analyzed and compared using ANOVA and Tukey HSD tests (P<0.05). Tetric Ceram was tested as commercial composite.
Results: There were significantly differences between three body abrasive wear of composites. The ranking from lowest to highest was as follows: leucite composite (19%) < Tetric Ceram (22%) < glass composite (28%). leucite composite showed the highest wear resistance value, propably due to the crystalliniy and hardness of filler.
Conclusion: Introduction of this new filler as an alternative to glass filler, significantly increases the wear resistance of the resin composites. Further investigations on mechanical properties of new composites would be beneficial in the development of new dental materials.
S. Arami , M. Tavassoti Kheiri , M. Hasani Tabayabaie , E. Yasini , A. Pahlavan , M. Ghavam , M. Mirzaie , H. Kermanshah , Sh. Forootan , S. Ahrabi , M. Tabatabaian , L. Mahrokh ,
Volume 20, Issue 4 (5 2008)
Abstract
Background and Aim: The efficiency of disinfecting materials and procedures in removal of contamination from dental surfaces and equipments is essential. In authors' previous study, daily use of 2:100 dilution of 5% sodium hypochlorite in water and disposable covers were recommended since HBV contamination was found on semi-critical parts of the operative dentistry department. The aim of this study was to evaluate the HBV contamination following application of the recommended procedures.
Materials and Methods: The study was conducted in two parts. In the first cross-sectional part, samples were collected from 17 sites of dental surfaces. In the second interventional part samples were collected from 10 sites of 9 dental and 3 sites of 2 light cure units, before and after disinfection with 5% sodium hypochlorite solution diluted to 2:100. Sterile cotton swabs moistened with sterile BSAS (Bovine Serum Albumin in Sodium Chloride) solution were used for sampling. Samples were tested by PCR technique in Pasteur Institute, Iran.
Results: None of the samples collected in the first part of the study showed contamination. In the second part of the study, from 96 samples taken from various parts of dental and light cure units, before and after disinfection, there was only one HBV contaminated site before disinfection which showed no contamination after disinfection.
Conclusion: Based on the results of this study, disinfecting procedure with 5% sodium hypochlorite solution diluted to 2:100 along with using disposable covers is effective in preventing HBV contamination.
A. Pahlavan, M. Ghavam, S. Arami, E. Yasini, M. Mirzaie, H. M.kermanshah, M. Hasani Tabatabaie, M. Bayrami,
Volume 21, Issue 1 (14 2008)
Abstract
Background and Aim: Because of polymerization shrinkage and high viscosity of posterior composites, there are some difficulties in using them in posterior restorations. Several methods have been represented to reduce the effect of shrinkage. The aim of this study was to investigate the effect of curing flowable composites under condensable ones in adaptation and microleakage reduction of posterior composite restorations.
Materials and Methods: In this experimental in vitro study, forty class II MO cavities were prepared on extracted intact molar and premolar human teeth. Gingival margins were placed 1 mm apical to CEJ. The teeth were divided into two groups. In group 1, flowable composite (Filek Flow, 3M, ESPE, USA) with 0.5-1 mm thickness was applied and cured following application of bonding agent (Single Bond, 3M, ESPE, USA). The rest of the cavity was filled by condensable composite (p60, 3M, ESPE, USA). In group 2 the flowable composite was not cured, and the condensable composite was applied in two increments. After light curing of composites, all the specimens were thermocycled and then immersed in 0.3% basic fuschin. Specimens were sectioned and evaluated for degree of dye penetration under a stereomicroscope. Data were analyzed by Mann-Whitney test with p<0.05 as the level of significance.
Results:. There was no significant difference between the two studied groups regarding microleakage.
Conclusion: Based on the results of this study, neither cured nor uncured flowable composite under condensable composite can omit microleakage in posterior composite restorations.
E. Yasini, M. Mirzaei, A. Pahlavan, M. Ghavam, M. Hasani Tabatabaie, S. Arami, H. Kermanshah, Sh. Tabatabaie,
Volume 21, Issue 2 (12 2008)
Abstract
Background and Aim: Amalgam is one of the mostly used restorative materials, but has some disadvantages. Microleakage is one of the short comings of amalgam which may lead to sensitivity and recurrent caries. The aim of this study was to evaluate the effect of three dentin bonding systems on reduction of microleakage in amalgam restorations.
Materials and Methods: Class II amalgam restorations were made in 40 noncarious molar and premolar teeth. Then the specimens were divided into four equal groups. Scotch Bond Multi Purpose, Single bond,
iBond, were used as liner in groups one to three respectively and in group four no liner was used. The teeth were restored with high copper spherical amalgam. After thermocycling for 500 cycles at 50C and 550C, the specimens were immersed in basic fuchsin for 24 hours, bisectioned mesiodistally and evaluated under stereomicroscope at X25 for dye penetration. The data were analyzed by Kruskal-wallis and Scheffe. P<0.05 was considered as the level of significance.
Results: The groups showed significant difference (p=0.003). The group four had significantly less microleakage than the first and second groups (p<0.05). The second and third groups showed significantly different microleakage (p=0.038).
Conclusion: Based on the results of this investigation applying dentin bonding agents has no effect on reducing microleakage in amalgam restorations, however more studies are recommended.
M. Atai, M. Ghavam, E. Yasini, M. Mirzaei, A. Pahlavan, M. Hasani Tabatabaie, S. Arami, H. Kermanshah, S. Kameli,
Volume 21, Issue 2 (12 2008)
Abstract
Background and Aim: Nonmetallic tooth- colored posts adhere to canal walls by dentin bonding agents and resin cements. Better retention and proper distribution of stress result from enough and proper bonding. The purpose of this study was to evaluate bond strength of D.T. Light - post with two different resin cements (self-cure & dual-cure) and to investigate the effect of irrigating solutions applied in root canal on bond strength of the resin cements and D.T.Light- post to root canal wall.
Materials and Methods: In this experimental study 40 single root teeth (maxillary canine & central) were selected and stored in 0.1% thymol solution for one week and transferred to distilled water. The teeth were decoronated 2mm above CEJ. The canal space was mechanically enlarged using k-files (up to # 70). The teeth were randomly divided into two groups. The first group was irrigated with 2.6% NaOCl, and the second was irrigated with normal saline. After drying, the teeth were filled with gutta percha cones using lateral condensing method. After two weeks the post space was prepared and D.T.Light- post was inserted in each subgroup using self or dual-cure cements according to manufacturer's instructions. After thermocycling, the apical part was cut 1cm below CEJ. The remained length was divided into 9 equal sequential sections. Each section was submitted to shear push-out test in universal testing machine. Statistical analysis of the bond strength data was performed using ANOVA and post hoc tests with p<0.05 as the level of significance. All failed specimens were examined under stereomicroscope. Degrees of conversion of the cements were determined by FTIR.
Results: Significant difference in bond strength values were found among sites (P=0.001) and cements (P=0.03). With increasing in depth, bond strength decreased. The mean bond strength value in dual-cure resin cement was higher than self-cure cement. The irrigating solutions caused no significant difference in bond strength (P=0.46). DC% had significant difference in various depths.
Conclusion: According to the results of this investigation, bond strength of dual-cure cement is higher than self-cure one in D.T Light- post because of post's translucency. 2.6% sodium hypochlorite does not affect the bond strength.
M. Ghavam, S. Arami, M. Hasani Tabatabaie, M. Mirzaei, H. Kermanshah, A. Pahlavan, E. Yasini, M. Dehghan,
Volume 22, Issue 3 (1 2009)
Abstract
Background and Aim: Decreasing the hardness of dental restorative composites after curing in oral environment can influence their clinical durability. The aim of this study was to evaluate the effect of food-simulating liquids such as 25%, 50%, 75 % ethanol and 50 % heptane on surface hardness of two composites - (Gradia and P60) after curing and immersing time of 24 hours and 7 days.
Materials and Methods: 45 specimens of each composite were prepared in a stainless steel mold with 6 mm diameter and 2 mm depth. 5 specimens of each composite were tested for microhardness immediately after curing as the control group. The other specimens of each composite were randomly divided into eight groups. Each specimen was immersed in one of the following solutions 25%, 50%, 75 % ethanol and 50 % heptane for either 24 hours or 7 days. Then the specimens were taken out of the solutions and washed and dried and transferred to the refrigerator until performing the test. In standard conditions, surface microhardness of specimens was evaluated by the microhardness device based on Vickers. The data were analyzed by one way ANOVA 3 way ANOVA and Tukey Post Hoc tests. The level of significance was set at p<0.05.
Results: Surface hardness of P60 composite was higher than that of Gradia. An analysis of variance in gradia and p60 showed significant difference between the control and all the other groups (P<0.05) except the 25% ethanol (P=0.514). After 24 hours all the solutions had significant effect on Gradia (P<0.05) except 50% and 75% ethanol (P=0.793). After 7 days all the solutions had significant effect on Gradia except 50% and 25% ethanol (P=0.385)and 50% and 75% ethanol (P=0.150) According to P60 after both 24 hours and 7 days all the solutions had significant effect on the hardness. 50 % heptane increased the hardness (P=0.00). 75% ethanol significantly decreased the hardness (P=0.000) followed by 50% (P=0.001) and 25% ethanol (P=0.007).
Conclusion: Based on the results of this study, the effect of time was not significant. P60 showed to be more resistant. 75% ethanol had much more effect followed by 50% and 25% ethanol. Heptane increased the mean surface hardness.
M. Ghavam, S. Arami, M. Reshad, M. Imani, M. Ataei, M. Mirzaei, E. Yasini, M. Hasani Tabatabaei, A. Pahlavan, H. Kermanshah ,
Volume 22, Issue 4 (21 2010)
Abstract
Background and Aims: In spite of the advances achieved in the field of dentin adhesives, the longevity of bond to dentin is still a challenge. According to recent studies, Matrix Metaloproteinase (MMP) inhibitors can increase clinical longevity of bonding and decrease leakage. The aim of this study was to evaluate the amount and pattern of doxycycline release from an experimental dentin adhesive containing this MMP inhibitor.
Materials and Methods: In this experimental study, specimens containing 0.25 and 0.5 loading percent of doxycycline in an experimental monomer were prepared in cylindrical moulds of 12 mm diameter and 2 mm thickness. The adhesive monomer was composed of 12 wt% Bis-GMA, 10 wt% TMPTMA, 28 wt% HEMA and 50 wt% ethanol. Camphorquinone and amine were used as initiators.
Results: Addition of 0.25 and 0.5 w% doxycycline showed linear release in both groups. Increasing the loading percent of doxycycline caused more release. The release continued during the test period.
Conclusion: Doxycycline release was observed from the experimental adhesive. Further studies in this field will help in preparing adhesive systems with more clinical longevity.
E. Yasini, H. Kermanshah, M. Mirzaie, B. Ranjbar Omidi,
Volume 24, Issue 3 (21 2011)
Abstract
Background and Aims: Marginal seal in class V cavities and determining the best restorative material to decrease microleakage is of great importance in operative dentistry. The aim of this study was to evaluate the effect of polishing time on the microleakage of three types of tooth-colored restorative materials in class V cavity preparations and to assess the marginal integrity of these materials using scanning electron microscope (SEM).
Materials and Methods: In this in vitro study, class V cavity preparations were made on the buccal and lingual surfaces of 30 bovine incisors (60 cavities). The specimens were divided into three groups each containing 10 teeth (20 cavities): group 1, Filtek Z350 (nanocomposite) group 2, Fuji IX/G Coat Plus (CGIC) and group 3, Fuji II LC (RMGI). In each group, half of the specimens (n = 20) were finished/polished immediately and the rest of them were finished/polished after 24 hours. All the specimens were thermocycled for 2000 cycles (5-50 °C). Epoxy resin replicas of 12 specimens (2 restorations in each subgroup) were evaluated using SEM and the interfacial gaps were measured. Finally, the teeth were immersed in 0.5% basic fuchsin dye for 24 hours at room temperature, sectioned and observed under stereomicroscope. The data were analyzed using Kruskal-Wallis and Mann-Whitney U tests and the comparison between incisal and cervical microleakage was made with Wilcoxon test.
Results: Incisal and cervical microleakage were not affected by polishing time in none of the three restorative materials (P>0.05). Cervical microleakage only in Fuji IX with immediate polishing was significantly higher than incisal microleakage (P<0.05). Incisal and cervical microleakage with immediate or delayed polishing were not significantly different in Fuji IX, Fuji II LC, and Z350 (P>0.05).
Conclusion: Immediate polishing is recommended in tooth-colored class V restorations.
Masoomeh Hasani Tabatabaie, Ayob Pahlavan, Esmaiel Yasini, Mansore Mirzaie, Sakineh Arami, Hamid Kermanshah, Hamidreza Sadeghipour Roudsari, Seyed Hossein Bassir, Taher Akbari Saeed, Hamed Hasani,
Volume 25, Issue 3 (1 2012)
Abstract
Background and Aims: There is concern that leached components from dental composites may cause adverse changes in the reproductive health. This study aimed to assess the effects of leached components from a hybrid resin composite on the reproductive system of male mice.
Materials and Methods: In the present animal study, twenty adult Syrian male mice were divided into two groups of 10 mice each. In the test group, components which leached from samples made from Filtek Z250 resin composite into 75% ethanol were daily administered to the mice for 28 days. In the control group, the procedure was repeated in the same way as the test group but without placing composite samples in the solution. Then, the body weight, weights of paired testes, Gonado Somatic Index, sperm viability, sperm motility, epididymal sperm reserve and daily sperm production were recorded. Four male mice in each group were mated with untreated female mice for 10 days. After that, the number of pregnant females and number of infants were recorded. The data were analyzed using repeated measures ANOVA, Chi-square test and t-test.
Results: There was a significant reduction in the sperm viability and sperm motility of male mice in the test group compared to the control group (P=0.001). There was no any significant differences in other parameters between two groups (P>0.05).
Conclusion: This study showed that the leached components from resin composites cannot cause infertility but they could potentially cause some adverse effects on the reproductive system of male mice.
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.
Hamid Kermanshah, Esmaiel Yasini, Razieh Hoseinifar,
Volume 26, Issue 1 (3-2013)
Abstract
Background and Aims: Marginal seal in class V cavity and determination of the best restorative material in reducing microleakage is of great concern in operative dentistry. The aim of this study was to evaluate the effect of load cycling on the microleakage of low shrinkage composites compared with methacrylate-based composites with low shirinkage rate in class V cavity preparation. Marginal integrity of these materials was assessed using scanning electron microscope (SEM).
Materials and Methods: In this in vitro study, class V cavity preparations were made on the buccal and lingual surfaces of 48 human premolars and molars (96 cavities). The specimens were divided into four groups each containing 12 teeth (24 cavities): group 1 (Kalore-GC+ G-Bond) , group 2 (Futurabond NR+Grandio), group 3 (All Bond SE+ Aelite LS Posterior), group 4 (LS System Adhesive Primer & Bond+Filtek P90). All the specimens were thermocycled for 2000 cycles (5-50oC). In each group, half of the specimens (n=12) were subjected to 200,000 cycles of loading at 80 N. Epoxy resin replicas of 32 specimens (4 restorations in each subgroup) were evaluated using SEM and the interfacial gaps were measured. Finally, the teeth were immersed in 0.5% basic fuchsin dye for 24 hours at 370C, then sectioned and observed under stereomicroscope. The data were analyzed using Kruskal-Wallis and Mann-Whitney U tests and the comparison between occlusal and gingival microleakage was made with Wilcoxon test.
Results: Within unloaded or loaded specimens, there were no significant differences in microleakage among four groups on the occlusal margins (P>0.05). But there were statistically significant differences in microleakage between silorane and Aelite on the gingival margins (P<0.05). No statistically significant differences were found between the microleakage of the loaded and unloaded groups on both occlusal and gingival margins for all materials (P>0.05).
Conclusion: Silorane did not perform better than the conventional low shrinkage methacrylate-based composite in terms of sealing ability (except Aelite). Cyclic loading did not increase the extent of leakage in any groups.
