scholarly journals Effect of fluoride on tooth erosion around orthodontic brackets

2012 ◽  
Vol 23 (5) ◽  
pp. 581-585 ◽  
Author(s):  
Erika Machado Caldeira ◽  
Tatiana Kelly da Silva Fidalgo ◽  
Paula Passalini ◽  
Mariana Marquezan ◽  
Lucianne Cople Maia ◽  
...  
Keyword(s):  
High Frequency ◽  
Great Influence ◽  
Orthodontic Brackets ◽  
Tooth Erosion ◽  
Frequency Of Use ◽  
Demineralized Enamel ◽  
Significant Difference ◽  
Fluoride Dentifrice ◽  
Opaque Surface ◽  
Experimental Group

The aim of the present study was to evaluate the effect of fluoride in prevention of tooth erosion around orthodontic brackets under erosive challenge. Edgewise brackets were bonded with TransbondTM XT composite on vestibular surface of 40 bovine incisors. The teeth were assigned to 4 groups (n=10): G1: Remineralizing saliva; G2: Erosive challenge; G3: Experimental group submitted to topical application of neutral fluoride gel (2% NaF) before erosive challenge; G4: Experimental group submitted to three daily applications of fluoride dentifrice (PFM 1500 ppmF) during erosive challenge. After 14 days of erosive challenge, direct visual and tactile examination were performed by two calibrated and trained examiners (Kappa = 0.867). The following scores were used: 0 = Intact enamel, 1 = Demineralized enamel without cavity, 2 = Demineralized enamel with cavity, 3 = Remineralized enamel without cavity, 4 = Remineralized enamel with cavity. Kruskal-Wallis and Mann-Whitney tests were applied to determine erosion levels, establishing a confidence interval of 95% (p<0.05). G2 and G3 presented 100% of score 2, with large cavities, presenting rough and opaque surface. G4 showed 50% of score 3 and 50% of score 4. Considering the studied conditions, it was found a significant difference between G2 and G4 and between G3 and G4 (p<0.01). By contrast to single application of neutral fluoride gel, the high frequency of use of fluoride at low concentration had a great influence during the dynamics of erosion.

scholarly journals Do enamel microabrasion and casein phosphopeptide-amorphous calcium phosphate affect shear bond strength of orthodontic brackets bonded to a demineralized enamel surface?

2011 ◽  
Vol 82 (1) ◽  
pp. 36-41 ◽  
Author(s):  
Asli Baysal ◽  
Tancan Uysal
Keyword(s):  
Calcium Phosphate ◽  
Bond Strength ◽  
Amorphous Calcium Phosphate ◽  
Shear Bond Strength ◽  
Enamel Surface ◽  
Orthodontic Brackets ◽  
Group I ◽  
Demineralized Enamel ◽  
Significant Difference ◽  
Casein Phosphopeptide

Abstract Objective: To evaluate and compare the effects of enamel microabrasion, casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), and their combination on the shear bond strength (SBS) of orthodontic brackets bonded to demineralized enamel surface. Materials and Methods: One hundred human first premolar teeth were randomly allocated to one of five groups. Group I was considered as the control of other groups. For the remaining groups, demineralization was performed via solutions. In group II, brackets were directly bonded to the demineralized enamel surface. CPP-ACP was applied in group III, microabrasion was performed in group IV, and both microabrasion and CPP-ACP application were performed in group V. The specimens were tested for SBS. Bond failures were scored according to the Adhesive Remnant Index (ARI). Analysis of variance and Tukey tests were used to compare the SBS of the groups. ARI scores of the groups were evaluated with a G-test. The statistical significance was set at P &lt;. 05 level. Results: Statistically significant difference was found among the five investigated groups (F  =  111.870; P &lt; .001). The SBS of groups II and IV were significantly lower than the other groups. No statistically significant difference was found among groups I (control; mean 24.1 ± 4.1 MPa), III (mean 22.0 ± 3.6 MPa), and V (mean 24.3 ± 1.9 MPa). Microabrasion and combination with CPP-ACP showed higher SBS compared to the control group. The differences between ARI scores of the groups were statistically significant (P &lt; .001). Conclusion: CPP-ACP pretreatment, microabrasion of the enamel, and the combination of these two methods improve the bonding to demineralized enamel.

scholarly journals The Effect of Remineralizing Agents With/Without CO2 Laser Irradiation on Structural and Mechanical Properties of Enamel and its Shear Bond Strength to Orthodontic Brackets

2020 ◽  
Vol 11 (2) ◽  
pp. 144-152
Author(s):  
Hannaneh Ghadirian ◽  
Allahyar Geramy ◽  
Waleed Shallal ◽  
Soolmaz Heidari ◽  
Nooshin Noshiri ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bond Strength ◽  
Laser Irradiation ◽  
Co2 Laser ◽  
Shear Bond Strength ◽  
Testing Machine ◽  
Orthodontic Brackets ◽  
Beam Diameter ◽  
Demineralized Enamel ◽  
Significant Difference

Introduction: Remineralizing agents may be used for the treatment of white spot lesions (WSLs) prior to bracket bonding. However, some concerns exist regarding their possible interference with the etching and bonding process, negatively affecting the bond strength. This study aimed to assess the effect of two remineralizing agents with/without CO2 laser irradiation on the mechanical properties and shear bond strength (SBS) of demineralized enamel to the orthodontic bracket. Methods: This study evaluated 60 premolar teeth in 6 groups (n=10) as follows: (I) sound enamel, (II) demineralized enamel, (III) Nupro remineralizing agent (N), (IV) Nupro and CO2 laser (N/L), (V) Teethmate remineralizing agent (T), and (VI) Teethmate and CO2 laser (T/L). The remineralizing agents were applied to the enamel surfaces after their immersion in a demineralizing solution for 5 days. In groups IV and VI, the CO2 laser with a 10.6 μm wavelength, 10 ms pulse duration, a 50 Hz repetition rate, 0.3 mm beam diameter and 0.7 W power was irradiated after applying the remineralizing agents. Brackets were bonded to the enamel surfaces and SBS was measured by a universal testing machine. For the assessment of enamel microhardness, 20 sections of molar teeth were divided into 4 groups (n=5; N, N/L, T, T/L) and their microhardness was measured before demineralization, after demineralization and after remineralization. X-ray diffraction (XRD) analysis, field-emission scanning electron microscopy (FESEM) and energy-dispersive spectrometry (EDS) were carried out to assess the formation of hydroxyapatite. The atomic percentages of the C, O, P, Ca, Na, Si, F and Ca/P ratio were determined by EDS analysis. Results: The SBS significantly decreased in group II (P<0.001). There was no significant difference among the groups I, III, IV, V and VI (P<0.05). This finding was similar to the microhardness results, which showed an increase in microhardness after remineralization (P<0.05), with no difference among the remineralizing agents. The Ca/P ratio was the highest in the Nupro group and the lowest in the demineralized group. Conclusion: Remineralizing agents can significantly improve the microhardness and structural properties of demineralized enamel to a level similar to that of sound enamel with no adverse effect on SBS to orthodontic brackets.

scholarly journals The Effect Of Speed Reading Instruction On Japanese High School Students English Reading Comprehension And Vocabulary Development

2011 ◽  
Vol 8 (1) ◽  
pp. 27-40
Author(s):  
Paul Underwood ◽  
Gordon Myskow ◽  
Takahiko Hattori
Keyword(s):  
High School ◽  
Reading Comprehension ◽  
High School Students ◽  
High Frequency ◽  
Vocabulary Development ◽  
Reading Rate ◽  
Control Group ◽  
Speed Reading ◽  
Significant Difference ◽  
Experimental Group

This study investigated the effects of a six-month course in speed reading in three areas of reading proficiency development: 1) general reading comprehension, 2) knowledge of high-frequency vocabulary, and 3) reading-rate and accuracy. The participants (N = 105) were Japanese students studying English as a foreign language in Grade 10 at a Japanese private senior high school, randomly assigned to an experimental group (n =51) which received the speed reading treatment, and a control group (n =54) which received supplementary activities focused on high-frequency vocabulary development. The findings indicated that both the experimental and control groups made significant improvements in general reading comprehension. However, there was no significant difference between the experimental group (M = 14.27, SD = 4.01) and the control group (M = 14.31, SD = 4.07); t (103) = -.051, p= .959. Both the experimental group (M = 1.29, SD = 2.52) and the control group (M = 1.35, SD = 2.49) increased their knowledge of high-frequency vocabulary. However, again there was no significant difference between the experimental group (M = 25.78, SD = 2.96) and the control group M = 25.61, SD = 2.24; t (103) = -.337, p= .737. In terms of reading-rate development, the findings indicated a significant increase (M = 47, SD = 41.99) t (50) = 8.01, p < .0005. Finally, while higher levels of general reading comprehension and high reading speeds were correlated, the relationship was small, r=.19, n = 51. The range of findings emerging from this current study adds weight to the existing research and goes beyond those conducted in the Japanese context to date. One of the important questions these findings raise relates to the greater influence that other variables, such as lexico-grammatical knowledge, might have on the development of reading comprehension at this level of language proficiency.

scholarly journals Does Mind Mapping Technique improve Cohesion and Coherence in Composition Writing? An Experimental Study

2020 ◽  
Vol 37 (2) ◽  
Author(s):  
Nazir Haider Shah
Keyword(s):  
Great Influence ◽  
Achievement Test ◽  
Mapping Technique ◽  
Control Group ◽  
Traditional Teaching ◽  
Teaching Techniques ◽  
Mind Mapping ◽  
Significant Difference ◽  
Post Test ◽  
Experimental Group

The purpose of this study was to compare the effectiveness of the instructions, founded on mind mapping and traditional teaching techniques for cohesive and coherent teaching in the composition writing of tenth-grade students. This study used a pre-test post-test control group design. Sixty (60) junior students (30 boys and 30 girls) from two schools were randomly selected. The students in the control group were guided by traditional teaching techniques, and the students in the experimental group were guided by the technique of mind mapping. The Subject Achievement Test (SAT) was conducted as a pre-test and post-test on two groups to assess student achievement. As a result, it was discovered that there was a significant difference in the average posttest scores between the experimental group and the control group in terms of the student's Subject Achievement Test (SAT). In addition, gender has a great influence on students' writing performance. The conclusion is that mind mapping technique was more effective than traditional techniques in terms of students' achievements in composition writing. The study has the potential to pave the way for future researchers. Keywords: Mind-mapping technique, composition writing, Grammar Translation Method, Subject Achievement Test, students’ achievement

scholarly journals Assessment of Enamel Demineralization Adjacent to Orthodontic Brackets Using a Polarized Microscope

2020 ◽  
pp. 030157422095169
Author(s):  
Santosh Ramegowda ◽  
Shilpa Joy ◽  
Nishitha C Gowda ◽  
Shailaja AM ◽  
Bharath Reddy ◽  
...  
Keyword(s):  
Polarized Light ◽  
Orthodontic Brackets ◽  
Fluoride Varnish ◽  
Control Group ◽  
Single Application ◽  
Enamel Demineralization ◽  
Time Period ◽  
Significant Difference ◽  
Experimental Group ◽  
Effect Of Light

Background and Objectives: This study was conducted to assess the effect of light-curable fluoride varnish on enamel demineralization adjacent to orthodontic brackets using polarized light microscopy and to compare the depth of demineralization at different time periods. Method: In 15 patients, the first premolars were allocated into 2 groups. In the experimental group light-curable fluoride varnish was applied. At the end of each time period (60, 90, and 120 days), first premolar brackets were debonded and premolars were extracted. Buccolingual sections were evaluated under a polarized light microscope and depth of demineralization was assessed. Results: The depth of demineralization in the control group increased from 60 to 120 days, and the experimental group did not show any significant difference during the time period. Conclusion: Single application of light-curable fluoride varnish, Clinpro XT can be effective in reducing enamel demineralization during fixed orthodontic mechanotherapy, especially in noncompliant patients.

Real Ear Sound Pressure Levels Developed by Three Portable Stereo System Earphones

1992 ◽  
Vol 1 (4) ◽  
pp. 52-55 ◽  
Author(s):  
Gail L. MacLean ◽  
Andrew Stuart ◽  
Robert Stenstrom
Keyword(s):  
High Frequency ◽  
Sound Pressure ◽  
Low Frequency ◽  
Test System ◽  
Output Frequency ◽  
Frequency Effects ◽  
Adult Men ◽  
Frequency Responses ◽  
Significant Difference ◽  
Sound Pressure Levels

Differences in real ear sound pressure levels (SPLs) with three portable stereo system (PSS) earphones (supraaural [Sony Model MDR-44], semiaural [Sony Model MDR-A15L], and insert [Sony Model MDR-E225]) were investigated. Twelve adult men served as subjects. Frequency response, high frequency average (HFA) output, peak output, peak output frequency, and overall RMS output for each PSS earphone were obtained with a probe tube microphone system (Fonix 6500 Hearing Aid Test System). Results indicated a significant difference in mean RMS outputs with nonsignificant differences in mean HFA outputs, peak outputs, and peak output frequencies among PSS earphones. Differences in mean overall RMS outputs were attributed to differences in low-frequency effects that were observed among the frequency responses of the three PSS earphones. It is suggested that one cannot assume equivalent real ear SPLs, with equivalent inputs, among different styles of PSS earphones.

Is perioperative antibiotic necessary in straightforward implant placement procedures?

2020 ◽  
Author(s):  
Elçin Bedeloğlu ◽  
Mustafa Yalçın ◽  
Cenker Zeki Koyuncuoğlu
Keyword(s):  
Clavulanic Acid ◽  
Dental Implant ◽  
Prophylactic Antibiotic ◽  
Antibiotic Use ◽  
Implant Failure ◽  
Control Group ◽  
Implant Placement ◽  
Significant Difference ◽  
Amoxicillin Clavulanic Acid ◽  
Experimental Group

The purpose of this non-random retrospective cohort study was to evaluate the impact of prophylactic antibiotic on early outcomes including postoperative pain, swelling, bleeding and cyanosis in patients undergoing dental implant placement before prosthetic loading. Seventy-five patients (45 males, 30 females) whose dental implant placement were completed, included to the study. Patients used prophylactic antibiotics were defined as the experimental group and those who did not, were defined as the control group. The experimental group received 2 g amoxicillin + clavulanic acid 1 h preoperatively and 1 g amoxicillin + clavulanic acid twice a day for 5 days postoperatively while the control group had received no prophylactic antibiotic therapy perioperatively. Data on pain, swelling, bleeding, cyanosis, flap dehiscence, suppuration and implant failure were analyzed on postoperative days 2, 7, and 14 and week 12. No statistically significant difference was detected between the two groups with regard to pain and swelling on postoperative days 2, 7, and 14 and week 12 ( p &gt;0.05), while the severity of pain and swelling were greater on day 2 compared to day 7 and 14 and week 12 in both groups ( p =0.001 and p &lt;0.05, respectively). Similarly, no significant difference was found between the two groups with regard to postoperative bleeding and cyanosis. Although flap dehiscence was more severe on day 7 in the experimental group, no significant difference was found between the two groups with regard to the percentage of flap dehiscence assessed at other time points. Within limitations of the study, it has been demonstrated that antibiotic use has no effect on implant failure rates in dental implant surgery with a limited number of implants. We conclude that perioperative antibiotic use may not be required in straightforward implant placement procedures. Further randomized control clinical studies with higher numbers of patients and implants are needed to substantiate our findings.

The Effect of Using Students Peer Teaching on Iraqi EFL Students' Achievement in the Course of Library and Research Work

2019 ◽  
Vol 1 (33) ◽  
pp. 693-714
Author(s):  
. Muntaha Sabbar Jebur
Keyword(s):  
Basic Education ◽  
Teaching Method ◽  
Research Work ◽  
Peer Teaching ◽  
Control Group ◽  
College Of Basic Education ◽  
Significant Difference ◽  
Post Test ◽  
Efl Students ◽  
Experimental Group

          Peer teaching is a strategy that allows the students to teach the new content to each other, and they must be accurately guided by instructors.     The researcher proposes that the use of students peer teaching  may promote students' achievement  and ensure the engagement of all the students in the learning process. Therefore, the researcher employs it as a teaching method aiming at investigating its  effect on Iraqi EFL students' achievement in the course of Library and Research Work .      The study hypothesizes that there is no significant difference between the students' achievement who are taught library and research work by students peer teaching  and that of the students taught by the traditional way. The experimental design of the study is Parallel Groups, Random Assignment, posttest. Each group consists of 35 students, chosen randomly from the Third Year Students at the Department of English in the College of Basic Education. Both groups were matched in terms of their age and parents' education. The experiment was fulfilled in the first course for 15 weeks during the academic year 2016-2017.       The same materials were presented to both groups. This included   units from Writing Research Paper by Lester D. . Post-test was constructed and exposed  The t-test for  independent samples was used to analyze the results and it is found out that there is a statistical difference between the two groups in their achievement because the calculated t- value 2.635 is bigger than the tabulated t- value which is 2.000, and also shown the superiority of the experimental group. The results indicate that the experimental group, who was taught Library and Research Work by peer teaching   was better than the control group, who was taught according to the traditional way. So, the null hypothesis is rejected. Finally, some recommendations and suggestions are presented in the light of the study findings. to a jury of experts to verify its validity and it was administered to both groups.

The Effectiveness of Using a Mobile Messenger as an Educational Supporting Tool among Nursing Students

2020 ◽  
Vol 4 (1) ◽  
pp. 67-77
Author(s):  
Rohimah Ismail ◽  
Chong Mei Chan ◽  
Wan Muhammad Azly W. Zulkafli ◽  
Hasnah Zani ◽  
Zainab Mohd Shafie
Keyword(s):  
Nursing Education ◽  
Nursing Students ◽  
Clinical Decision Making ◽  
Intervention Group ◽  
Great Influence ◽  
Control Group ◽  
P Value ◽  
Significant Difference ◽  
Supporting Tool ◽  
Nursing College

                The evolution of information technology has exerted great influence on nursing education via new pedagogy of knowledge delivery without time and place restriction. Mobile technology revolutionises nursing education and clinical practice via empowering skills of critical thinking and clinical decision-making through learning. The aim of this study is to evaluate the effectiveness of using mobile messenger (Whatsapp) as an educational supporting tool among nursing students. The study design used is a Cluster Randomized Control Trail. Two nursing colleges were selected. Sample size was 93 participants, 48 from the Kuala Terengganu Nursing College Kuala Terengganu as the intervention group while the control group were recruited among 45 participants from UniSZA Nursing College. There is a significant difference in the level of knowledge between pre and posttest among intervention group (mean difference was -8.70 with a standard deviation 8.42, p-value< 0.001) and 93.8 percent of the respondents perceived the usefulness of using WhatsApp mobile messenger to enhance learning. This demonstrates that learning through mobile messenger (WhatsApp) enhances learning and is well received as a new method of learning by almost all students.   Keywords: Mobile learning, WhatsApp messenger, Social Interaction

Optimization of postoperative management of patients undergoing functional endoscopic sinus surgery

2018 ◽  
pp. 26-31
Author(s):  
Sergey Bezshapochny ◽  
Andrey Loburets ◽  
Valery Loburets
Keyword(s):  
Nasal Cavity ◽  
Postoperative Period ◽  
Sodium Hyaluronate ◽  
Sinus Surgery ◽  
Control Group ◽  
Nasal Breathing ◽  
Traditional Therapy ◽  
Significant Difference ◽  
Water Salt ◽  
Experimental Group

Topicality: The result of surgical treatment depends largely on the chosen method of management of the postoperative period, the main purpose of which is to reduce the effects of surgical trauma. Despite the wide variety of drugs for local and systemic use, the question of pharmacotherapy of the operated sinus remains open to this day. The main properties that a modern drug should possess are safety and high clinical efficacy. Aim: to study the clinical efficacy of topical application of a complex preparation based on a saline solution containing sodium hyaluronate and dexpanthenol in patients with chronic sinusitis after functional endoscopic sinus surgery (FESS). Materials and Methods: Clinical and laboratory studies were conducted on 47 patients with chronic rhinosinusitis who underwent surgery using the FESS technique. Patients were divided into 2 groups according to the principle of the postoperative period. Patients of research group (n=21), except for traditional therapy, was used locally NASOMER (a preparation based on a water-salt solution containing sodium hyaluronate and dexpanthenol); to the control group (n=26) patients entered, in the postoperative period received traditional therapy. Traditional therapy included a toilet of the nasal cavity, the use of short-course topical decongestants, irrigation of the nasal cavity with water-salt solutions. Criteria of clinical effectiveness: data of endoscopy of the nasal cavity, rhinomanometry, activity of the mucociliary transport system. The effectiveness of functional research methods in the postoperative period was determined on the 7th and 14th day of treatment. Results: On the 3rd day of the study, an increase in the swelling of the nasal cavity was observed in patients of both clinical groups, correlated with difficulty in nasal breathing. On the 7th day, a decrease in edema was observed in patients of both groups, but in the experimental group, the index of nasal breathing, according to rhinomanometry, was significantly (p<0.05) different from the control group, and was respectively 1.54±0.14 and 2.04±0.19 kPa/l*s. On the 14th day of the study, no significant difference was observed between these indicators. When studying the activity of the ciliated epithelium of the mucous membrane of the nasal cavity, it was proved that patients of the experimental group on day 7 after surgery showed a statistically significant difference in this indicator compared to the control group (17.8±1.0 and 22.7±2.1 min. respectively). Conclusions: The use of NASOMER after surgical intervention in patients with chronic rhinosinusitis contributes to more effective treatment compared with traditional therapy, as evidenced by the rapid recovery of the main functional parameters according to active posterior rhinomanometry and mucociliary clearance. Based on the results of the studies performed, the use of NASOMER for pharmacotherapy in the postoperative period is recommended for patients who have undergone rhinosurgical interventions with the aim of reducing the period of postoperative rehabilitation as an effective anti-inflammatory and wound-healing agent.

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