Scanning electron microscope and shear bond strength analysis of Biofix and Orthocem two-step fluoridated orthodontic adhesives on human enamel

Introduction: The bonding process in orthodontic treatment is very important. This study aimed to evaluate the shear bond strength (SBS) and bond failure sites of stainless steel brackets bonded with two new two-step adhesives (Biofix (BF) and Orthocem (OC)) and a three-step adhesive (Transbond XT (TXT)). Material & Methods: In this in vitro study, 66 extracted human premolars were collected and randomly divided into three groups (n=22). The brackets were bonded to each tooth with a) TXT, b) BF, and c) OC adhesives according to manufacturers’ instructions. The SBS values of the brackets were measured 24 hours after thermocycling. Adhesive remnant index (ARI), enamel detachment index (EDI) and bond failure locations on bracket surfaces were qualitatively and quantitatively assessed using stereomicroscopic, scanning electron microscope (SEM) and energy dispersive x-ray (EDX) analyses. The data were analyzed using SPSS 22 software and ANOVA test. The significance level was defined at P<0.05. Results: The means and standard deviations of SBS values for TXT, BF and OC adhesives were 22.49±4.58, 17.82±6.43 and 16.20±4.46 MPa, respectively. The SBS in the TXT group was significantly different from the two other groups, but the difference was not significant between the two other groups. Moreover, ARI and EDI were not significantly different between the three groups. The SBS values of BF (P<0.001) and OC (P<0.001) were not significantly different. Conclusion: The adhesive SBS in the BF and OC groups was in the determined ranges to bond the orthodontic brackets. Therefore, these two adhesives can be used as a proper alternative for conventional bonding methods

Comparison of shear bond strength of the stainless steel metallic brackets bonded by three bonding systems

Introduction: In orthodontic treatment, it is essential to establish a satisfactory bond between enamel and bracket. After the self-etch primers (SEPs) were introduced for the facilitation of bracket bonding in comparison to the conventional etch-and-bond system, multiple studies have been carried out on their shear bond strengths which have yielded different results. This study was aimed at comparing shear bond strengths of the stainless steel metallic brackets bonded by three bonding systems. Methods: In this experimental in vitro study, 60 extracted human maxillary premolar teeth were randomly divided into three equal groups: in the first group, Transbond XT (TBXT) light cured composite was bonded with Transbond plus self-etching primer (TPSEP); in the second group, TBXT composite was bonded with the conventional method of acid etching; and in the third group, the self cured composite Unite TM bonding adhesive was bonded with the conventional method of acid etching. In all the groups, Standard edgewise-022 metallic brackets (American Orthodontics, Sheboygan, USA) were used. Twenty-four hours after the completion of thermocycling, shear bond strength of brackets was measured by Universal Testing Machine (Zwick). In order to compare the shear bond strengths of the groups, the variance analysis test (ANOVA) was adopted and p≤0.05 was considered as a significant level. Results: Based on megapascal, the average shear bond strength for the first, second, and third groups was 8.27±1.9, 9.78±2, and 8.92±2.5, respectively. There was no significant difference in the shear bond strength of the groups. Conclusions: Since TPSEP shear bond strength is approximately at the level of the conventional method of acid etching and within the desirable range for orthodontic brackets shear bond strength, applying TPSEP can serve as a substitute for the conventional method of etch and bond, particularly in orthodontic operations

The use of urinary Insulin-like Growth Factor-I (IGF-I) for determining skeletal age of participants

Introduction: Biochemical markers play an important role in the growth and repair of bone and can be evaluated in different biological fluids. Therefore, the aim of this study was to evaluate the level of insulin-like growth factor-I (IGF-I) in urine as a puberty index and to compare it with cervical vertebral maturational stages (CVMSs) in lateral cephalometry. Materials&Methods: In this cross-sectional study, 50 8-18-year-old patients (males and females), referred to Faculty of Dentistry with CVMS of 2 to 6 and needed orthodontic treatment as well as lateral cephalometry were selected. All of these patients were healthy. The CVMSs were recorded based on lateral cephalometric radiographs and urinary levels of IGF-I was determined using a urine-based ELISA kit. Mean IGF-I values for each CVMS were analyzed by Mann-Whitney, Kruskal-Wallis and Chi-square tests in SPSS. P<0.05 was statistically considered as significant level. Results: In this study, the mean age of participants, ranged from 8 to 18 years was 12.96±3.82. There was no statistically significant difference in gender distribution between CVM groups (P=0.106). The level of urinary IGF-I had no significant difference between groups, except for CVMS3 group (P=0.073). In CS3, the mean urinary IGF-I level was 0.2727, representing a significant difference from other groups (P=0.000). IGF-I levels had no significant differences between males (0.030.04) and females (0.080.011), (P=0.492). Conclusion: The highest urinary IGF-I level was found in both genders in CVMS 3 and 4, which coincided with peak growth spurt in patients

Measurement of iron, magnesium and chromium concentrations in the saliva of the patients undergoing fixed orthodontic treatment

Introduction: Stainless steel alloy used in orthodontics has elements such as iron - magnesium and chromium, which may be released due to corrosion in the mouth. The aim of this study was to evaluate the changes of these elements in the saliva of patients undergoing fixed orthodontic treatment. Methods: In a clinical study with simple non-random sampling, 1ml saliva of 11 patients (7 females and 4 males) who needed fixed orthodontic treatment and had no restorations or crowns were collected. During the fixed orthodontic treatment at successive times (a day, a week, a month, two months and six months), 1 ml of saliva was collected and evaluated for the amount of iron (spectrophotometry), chromium (atomic absorption), and magnesium (spectrophotometry). Bracket, band and wire used in all patients were stainless steel alloy and were manufactured by Dentaurum Company. After sample collection, the data analysis was performed with "Azeri-5" and "10 SPSS" software and repeated measures test. Results: The mean concentration of iron 66.326±0.541, chromium 0.483±0.324 and magnesium 0.552±293 decreased during the study but these results were not statisticaly significant (p>0.05). Conclusions: Iron, chromium and magnesium concentration do not exceed the standard limits in saliva during orthodontic treatment

Evaluation of soft tissue norms on lateral cephalograms in babol

Introduction: Soft tissue has a prominent role in diagnosis and treatment plan in orthodontics. Facial proportions are measurable on lateral cephalograms. The purpose of this study was to compare the means of the normal soft tissue proportions of babol people with the norms of Caucasians. Materials & Methods: In this cross-sectional study, 100 cases with normal occlusion and proportional facial profile were participated from babol. After taking radiographs and tracing, the soft tissue variables were analyzed to find means and standard deviations. The data were compared with Caucasian's norms using T-test. Results: The norms of following variables in babol people were significantly different from those of Caucasians: facial convexity, nasolabial angle, upper lip thickness, chin soft tissue thickness and protrusion of lower lip. Conclusion: In babol, people have a more convex profile, more prominent nose and lower lip than caucasians

Evaluation of frictional resistance between monocrystalline (ICE) brakcets and Stainless Steel, Beta TMA and NiTiarch wires

Introduction: When using sliding mechanics for space closure during orthodontic treatment, friction occurs at the bracket-wire interface. The aim of this study was to evaluate the frictional resistance between monocrystalline (ICE) brackets and Stainless Steel, Beta TMA and NiTi wires. Methods: In this experimental study, we used 5 different types of orthodontic wires. Brackets and wires were divided in to 5 groups: 1-(monocrystalline+stainless steel 18) 2–(monocrystalline+stainless steel 19×25) 3-(monocrystalline+Beta-TMA) 4–(monocrystalline+Beta TMA 19×25) 5-(monocrystalline+NiTi 18). Instron Universal Testing Machine was used to investigate the static frictional resistance. The angulation between bracket and wire was 0 and the wires were pulled through the slots at a speed of 10 mm/min. Tests were performed 10 times for each group in artificial saliva. The average of 10 forces recorded was considered as static friction. One-way ANOVA and SPSS Version 18 and LSD post hoc test were used to evaluate the results of the study. Results: The mean static frictional force for each group was: group1: 0.82±0.14, group 2: 1.09±0.30, group 3: 0.87±0.53, group 4: 1.9±1.16, group 5: 1.42±0.30. There was a significant difference when comparing the two groups of similar wires in terms of shape (round or rectangular cross-section) as when comparing Beta TMA 18 and 19×25 arch wires with each other, the obtained p-value was 0.023, while the obtained p-value for the comparison of stainles steel arch wires was 0.034. Conclusions: The result of this study shows that Stainless Steel 18 wires generate the least amount of friction and round wires produce less friction than the rectangular wires. Beta TMA wires generate the highest amount of friction

Determination Relation of the Zinc Serum Level in Acute Leukemia Adult Patients with Mucositis and Neutropenic Prevalence before and after Treatment in Isfahan' Seyed-Al-Shohada Hospital, 2012–2013

Background: Neutropenic fever and mucositis with 70% outbreak average is one of the major reasons of death in the acute leukemia adult patients. The aim of this study was to determine the relationship of serum zinc level with neutropenic fever and mucositis prevalence in acute leukemia adult patients and comparison of the effects of therapeutic intervention with the serum zinc correct level in the group of patients with zinc deficiency. Materials and Methods: From May 2012 to May 2013 in a double-blind, randomized, placebo-controlled study, on the basis of zinc serum level, 40 acute leukemia adult patients were divided into two groups of normal and deficiency zinc, and neutropenic fever and mucositis prevalence were taken into consideration in each and every group. The deficiency zinc patients were randomly allocated to zinc or control group in a blocked randomization schedule. The data analysis was performed by SPSS software 20 and with the aid of variance analysis statistical method, logistic regression, and X2statistical test. Results: Serum zinc level was higher in acute leukemia adult patients without mucositis and neutropenic fever than others but was not statistically significant. There is a positive relation between receiving zinc with recovery; although the relationship has not become statistically significant. Conclusion: These data, although preliminary, suggest that zinc therapy could be a valid therapeutic adjuvant to improve the quality-of-life of acute leukemia adult patients

Evaluation of frictional resistance between monocrystalline (ICE) brakcets and Stainless Steel, Beta TMA and NiTi arch wires

Introduction: When using sliding mechanics for space closure during orthodontic treatment, friction occurs at the bracket-wire interface. The aim of this study was to evaluate the frictional resistance between monocrystalline (ICE) brackets and Stainless Steel, Beta TMA and NiTi wires. Methods: In this experimental study, we used 5 different types of orthodontic wires. Brackets and wires were divided in to 5 groups: 1-(monocrystalline+stainless steel 18) 2–(monocrystalline+stainless steel 19×25) 3-(monocrystalline+Beta-TMA) 4–(monocrystalline+Beta TMA 19×25) 5-(monocrystalline+NiTi 18). Instron Universal Testing Machine was used to investigate the static frictional resistance. The angulation between bracket and wire was 0 and the wires were pulled through the slots at a speed of 10 mm/min. Tests were performed 10 times for each group in artificial saliva. The average of 10 forces recorded was considered as static friction. One-way ANOVA and SPSS Version 18 and LSD post hoc test were used to evaluate the results of the study. Results: The mean static frictional force for each group was: group1: 0.82±0.14, group 2: 1.09±0.30, group 3: 0.87±0.53, group 4: 1.9±1.16, group 5: 1.42±0.30. There was a significant difference when comparing the two groups of similar wires in terms of shape (round or rectangular cross-section) as when comparing Beta TMA 18 and 19×25 arch wires with each other, the obtained p-value was 0.023, while the obtained p-value for the comparison of stainles steel arch wires was 0.034. Conclusions: The result of this study shows that Stainless Steel 18 wires generate the least amount of friction and round wires produce less friction than the rectangular wires. Beta TMA wires generate the highest amount of friction

Evaluation of Static Friction of Polycrystalline Ceramic Brackets after Conditioning with Different Powers of Er:YAG Laser

This research aimed to reduce the friction between the wire and brackets by Er:YAG laser. To measure the friction between the wires and brackets in 0° and 10° of wire angulations, 40 polycrystalline ceramic brackets (Hubit, South Korea) were divided into 8 study groups and irradiated by 100, 200, and 300 mj/s of Er:YAG laser power. Two groups of brackets were not irradiated. The friction between the wires and brackets was measured with universal testing machine (SANTAM) with a segment of .019 × .025 SS wire pulled out of the slot of bracket. ANOVA and t-test were used for analyzing the results. To evaluate the effect of the laser on surface morphology of the bracket, SEM evaluations were carried out. The mean frictional resistances between the brackets and wires with 0° of angulation by increasing the laser power decreased compared with control group, but, in 10° of angulation, the friction increased regardless of the laser power and was comparable to the friction of nonirradiated brackets. Furthermore, with each laser power, frictional resistance of brackets in 10° of angulation was significantly higher than 0° of angulation. These results were explained by SEM images too