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 ◽  
...  

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.

2020 ◽  
Vol 54 (1) ◽  
pp. 14-23
Author(s):  
Sudipta Chakraborty ◽  
Harshavardhan Kidiyoor ◽  
Anand K. Patil

Objectives: Various fluoride varnishes have shown promising result in preventing enamel demineralization around orthodontic brackets as they do not depend on patient compliance. The objective of the study was to compare the effect of light-curable fluoride varnish (Clinpro XT) and conventional topical fluoride varnish (Fluoritop SR) in preventing enamel demineralization adjacent to orthodontic brackets. Methods: 20 patients who required extraction of four first premolars for orthodontic treatment were bonded with orthodontic brackets and each premolar received single application of Clinpro XT and Fluoritop SR fluoride varnish in 2 diagonally opposite quadrants and rest 2 premolars acted as control. The sample teeth were debonded and extracted after 1 month and 2 months of varnish application. The samples were sectioned using hard tissue microtome and evaluated under polarized light microscopy to measure the depth of demineralization. Results: Kolmogorov Smirnov test showed normal distribution of data. Comparison between the study groups with depth of demineralization scores showed statistically significant variation in one-way analysis of variance test. Turkey’s multiple post hoc procedures showed statistically significant difference in the depth of demineralization between all the 3 groups after 1 month and 2 months. Dependent t test showed statistically significant increment in the depth of demineralization in all the 3 groups between 1 month and 2 months. Conclusion: This study concluded that single application of both Fluoritop SR and Clinpro XT was effective in reducing significant depth of demineralization compared to control. Clinpro XT showed significantly less demineralization compared to Fluoritop SR after 1 month and 2 months of varnish application.


2018 ◽  
Vol 8 ◽  
pp. 200-203 ◽  
Author(s):  
Kristin G. Saunders ◽  
Gianina Mattevi ◽  
Kevin J. Donly ◽  
Ravikumar Anthony

IntroductionEnamel demineralization adjacent to orthodontic brackets has been shown to be a consequence during orthodontic treatment. Fluoride-releasing resin-modified glass ionomer cements (RMGICs) have been shown to protect the enamel from white spot lesions, but their bond strength has been proven inadequate. The purpose of this study was to evaluate ACTIVA BioACTIVE-RESTORATIVE, a bioactive material with strength superior to RMGICs, for inhibition of enamel demineralization surrounding orthodontic brackets.Materials and MethodsFifteen human teeth were sectioned and divided into two groups. One group was the control and had orthodontic brackets bonded with Transbond XT, while the second group had orthodontic brackets bonded with ACTIVA. The teeth were varnished within 2 mm of the bracket margins and immersed in an artificial caries solution for 3 days to create carious lesions. The teeth were sectioned and viewed under polarized light microscopy for the detection of enamel demineralization adjacent to the bracket, and then, the lesion areas were measured with a computer imaging system.ResultsThere was a statistically significant difference (P≤ 0.001) that ACTIVA had less enamel demineralization adjacent to the bracket when compared to the control group.ConclusionsThe results of this study have demonstrated that ACTIVA, a fluoride-releasing bioactive restorative material, inhibits demineralization of enamel adjacent to orthodontic brackets when compared to a nonfluoride-releasing control.


2018 ◽  
Vol 89 (1) ◽  
pp. 10-15
Author(s):  
Moufida Abufarwa ◽  
Amal Noureldin ◽  
Phillip M Campbell ◽  
Peter H Buschang

ABSTRACT Objectives: To test how long casein phosphopeptide–amorphous calcium phosphate (CPP-ACP) fluoride varnish prevents enamel demineralization in vitro. Materials and Methods: Human molars and premolars were sectioned buccolingually and randomly assigned to two groups. Standardized pretreatment images of enamel surfaces were obtained using FluoreCam. The control group received no treatment, and the experimental group received an application of CPP-ACP fluoride varnish. Over simulated periods of 2, 4, 8, and 12 weeks, specimens were placed in a toothbrushing simulator, thermocycled, subjected to 9 days of pH cycling, and imaged with FluoreCam. Samples were sectioned and polished for polarized light microscope (PLM) evaluation. Results: There were statistically significant time (P < .001) and varnish (P < .001) effects on area, intensity, and impact of enamel demineralization. The control group showed significant and progressive demineralization over the 12 weeks (P < .001). The experimental group revealed no significant demineralization during the first 4 weeks (P > .05) and significant (P < .001) increases thereafter. Experimental demineralization after 12 weeks was comparable to 2-week demineralization in the controls, with significant between-group differences (P < .001) in enamel demineralization at all time points. PLM of the control and experimental groups revealed lesion depths of 90 ± 34 μm and 37 ± 9 μm, respectively. Conclusions: Within the limitations of this in vitro study, CPP-ACP fluoride varnish prevents enamel demineralization for at least 4 weeks and limits demineralization up to 12 weeks.


2014 ◽  
Vol 34 (7) ◽  
pp. 707-717 ◽  
Author(s):  
S-J Hong ◽  
D Zhang ◽  
L-H Zhang ◽  
P Yang ◽  
J Wan ◽  
...  

Objectives: To observe the expression of the dopamine transporter (DAT) in six cerebral regions of a methamphetamine (MA)-dependent rat, which were frontal cortex, nucleus accumbens septi, striatum, hippocampus, substantia nigra and ventral tegmental area. Methods: The rats were administrated intraperitoneally with 10 mg/kg/day of MA for 10 days consecutively; the behaviour changes were measured via the conditioned place preference (CPP), and the scores of stereotyped behaviour (SB) were used to confirm animal addiction. Then, the animals were further injected with MA respectively for 1, 2, 4 and 8 weeks to establish different periods of MA-dependent models. The expressions of DAT and DAT messenger RNA in six cerebral regions were detected. Results: The results of CPP and SB scores were significant different when comparing all four experimental groups with the control group ( p < 0.05). Comparing between different experimental groups, the expression of DAT mainly decreased and had dynamic changes in the same regions ( p < 0.05). Comparing the different regions with each other in the same experimental group, the expression of DAT also had significant difference in several regions p < 0.05). Conclusions: The expression of DAT mainly decreased and had different in the six cerebral regions at the same MA-dependent time period as well as at different time periods in the same cerebral region. It was speculated that DAT might play a crucial role in the mechanism of MA dependence.


2015 ◽  
Vol 148 (5) ◽  
pp. 814-820 ◽  
Author(s):  
Anurag Mehta ◽  
Ganesh Paramshivam ◽  
Vinay Kumar Chugh ◽  
Surjit Singh ◽  
Sudha Halkai ◽  
...  

2021 ◽  
Author(s):  
Moufida Abufarwa ◽  
Amal Noureldin ◽  
Rosemary Dziak ◽  
David Covell

ABSTRACT Objectives To compare efficacy of casein phosphopeptide (CPP)–amorphous calcium phosphate (ACP) fluoride varnish and light-curable resin modified glass ionomer fluoride varnish (FV) in preventing white spot lesions and evaluating acid etching prior to CPP-ACPFV application on its efficacy. Materials and Methods Molars and premolars were transected and halves divided into four groups (n = 18/group): (1) resin-modified glass ionomer FV: etched and Clinpro-XT varnish (3M ESPE, Pymble, New South Wales, Australia) application; (2) CPP-ACPFV: MI varnish (GC America, Alsip, IL) application; (3) Etch+CPP-ACPFV: etched and MI varnish application; (4) Control: etched and no surface treatment. To simulate 12 weeks in an intraoral environment, samples were subjected to thermocycling, brushing, and pH cycling. Enamel surface microhardness was evaluated at baseline and after the simulated 12 weeks. Representative samples were also assessed using scanning electron microscopy (SEM). Results At baseline there was no significant difference in microhardness among groups. After the simulated 12 weeks, all groups showed significant within-group differences (P &lt; .001). Control showed the highest percentage loss of surface microhardness (89%), followed by CPP-ACPFV (58%), RMGIFV (51%), and Etch+CPP-ACPFV (24%). The control group had a significant decrease in microhardness compared to all experimental groups (P &lt; .001). No difference was found between the RMGIFV and CPP-ACPFV varnish groups. The Etch+CPP-ACPFV group had significantly less decrease in microhardness compared to the RMGIFV (P &lt; .001) and CPP-ACPFV groups (P &lt; .001). With SEM, control samples showed signs of enamel surface damage, while experimental groups showed spherical particles on a relatively intact surface. Conclusions RMGIFV and CPP-ACPFV are effective in reducing enamel demineralization. Acid etching the enamel surface prior to CPP-ACPFV varnish application increased its efficacy.


2020 ◽  
Vol 90 (3) ◽  
pp. 369-375
Author(s):  
Samar M. Adel ◽  
Eiman S. Marzouk ◽  
Nadia El-Harouni

ABSTRACT Objectives To compare the effect of use of laser, casein phosphopeptide–amorphous calcium phosphate (CPP–ACP), and their combination on prevention of enamel demineralization using polarized light microscopy to assess lesion depth. Materials and Methods Eighty premolars were randomly allocated to four equal groups (n = 20): Group I: Control group, no preventive measures. Group II: CPP–ACP. Group III: Er,Cr:YSGG laser. Group IV: Er,Cr:YSGG laser followed by CPP–ACP. Specimens were subjected to thermocycling and brushing protocols equivalent to 1 year intraorally. Then, all teeth were subjected to acid challenge. Teeth were then sectioned longitudinally and examined under a polarized light microscope and lesion depth was measured. Results Group IV resulted in the least lesion depth with a significant difference between it and all other groups. CPP–ACP alone and laser alone also showed a significant difference in white spot lesion (WSL) depth compared to the control group; however, no significant difference was found between them. Conclusions The combined use of laser and CPP–ACP showed the best prevention against WSL development. The use of CPP–ACP or laser alone also resulted in a significant reduction in lesion depth but was significantly less than their combined use, with no significant difference between them.


2019 ◽  
Vol 24 (6) ◽  
pp. 48-55
Author(s):  
Carina Faleiros Demito ◽  
Julyano Vieira da Costa ◽  
Marina de Lourdes Calvo Fracasso ◽  
Adilson Luiz Ramos

ABSTRACT Objective: To assess in situ the effect of fluoride associated with nano-hydroxyapatite for the prevention of demineralization of the enamel adjacent to orthodontic brackets. Material and Methods: Eight volunteers wore palatal devices prepared with 6 bovine enamel blocks (5x5x2 mm) with bonded brackets. The volunteers used the devices in two different moments of 14 days each. During the first 14 days, a product containing fluoride + nano-hydroxyapatite was applied twice (experimental group, GNH, n = 48), and for the other 14 days no prevention product was applied (control group, CG, n = 48). In both groups, along the experiment, the blocks were dripped with 20% sucrose eight times daily. After the experiment, all the specimens were sectioned and examined for lesion depth analysis (µm) under polarized light microscopy, and for enamel longitudinal microhardness (measured under the bracket, at 30 µm and at 130 µm from the margin), at seven different depths (10, 20, 30, 50, 70, 90, and 110 µm). Results: Under polarized light, group GNH presented significantly less demineralization depth ( X ¯= 15.01 µm, SD = 33.65) in relation to CG ( X ¯= 76.43 µm, SD = 83.75). Enamel longitudinal microhardness demonstrated significantly higher microhardness for group GNH when compared to CG. Conclusion: Fluoride + nano-hydroxyapatite can be an alternative preventive procedure for demineralization of the enamel adjacent to orthodontic brackets.


Author(s):  
Elçin Bedeloğlu ◽  
Mustafa Yalçın ◽  
Cenker Zeki Koyuncuoğlu

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.


2019 ◽  
Vol 1 (33) ◽  
pp. 693-714
Author(s):  
. Muntaha Sabbar Jebur

          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.


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