scholarly journals Real-Time Feedback of the Applied Light-Curing Technique and Its Impact on Degree of Conversion of Composite Restorations—A Study with Undergraduate Dental Students

2021 ◽  
Vol 11 (10) ◽  
pp. 1012
Author(s):  
Phoebe Burrer ◽  
Matej Par ◽  
Thomas Attin ◽  
Tobias T. Tauböck
Keyword(s):  
Real Time ◽  
Dental Students ◽  
Degree Of Conversion ◽  
Patient Simulator ◽  
Light Irradiance ◽  
Composite Restorations ◽  
Significant Difference ◽  
Before And After ◽  
Light Curing ◽  
And Training

The objective of this study was to investigate the effect of individual instructions and training of dental students on the amount of applied light irradiance before and after training using a patient simulator with integrated visual feedback. Furthermore, the effect on the degree of conversion of composite restorations placed by the dental students was assessed. Forty-two dental students, split into two groups, light-cured a simulated restoration in tooth 27 of a dental patient simulator for 20 s. The irradiance (mW/cm2) received by the detector was measured in real-time before and after individual instructions and training, and the energy delivered (J/cm2) was calculated for each student. The degree of conversion at the bottom of incrementally placed composite restorations prior to individual instructions (group 1) and after individual instructions (group 2) was assessed using Fourier-transform infrared (FTIR) spectroscopy. The irradiance and degree of conversion measurements were re-assessed after all students received individual instructions. Data were analyzed using Wilcoxon signed-rank test and Mann–Whitney U-test at an overall level of significance of ⍺ = 0.05. A significant increase (p < 0.001) in applied light irradiance could be observed after individual instructions for both groups, with notably reduced data scattering. However, no significant difference was detected for the degree of conversion of placed composite restorations before or after instruction and training. Neither gender nor age of the dental students affected the obtained results. Consistent light energy delivered by dental students could be achieved through individual instructions and training with a patient simulator, also leading to less scattered irradiance results. However, the improved light-curing performance after the training did not affect the degree of conversion of the placed class II composite restorations.

scholarly journals Effectiveness of Using a Patient Simulator with Real-Time Feedback to Improve Light-Curing Skills of Dental Students

2020 ◽  
Vol 10 (22) ◽  
pp. 8269
Author(s):  
Tobias T. Tauböck ◽  
Matej Par ◽  
Thomas Attin ◽  
Phoebe Burrer
Keyword(s):  
Real Time ◽  
Visual Feedback ◽  
Training Group ◽  
Dental Students ◽  
Rank Test ◽  
Control Group ◽  
Similar Data ◽  
Patient Simulator ◽  
Hands On ◽  
Light Curing

The present study investigated the effectiveness of employing a patient simulator with an integrated visual feedback mechanism to improve the light-curing skills of dental students. A total of 44 third-year dental students were randomly divided into a control group (n = 22) and a training group (n = 22). Both groups light-cured a simulated restoration in tooth 27 in a patient simulator (MARC Patient Simulator, BlueLight Analytics, Halifax, Canada) by using the same curing device for 10 s. Delivered irradiances were recorded in real time by the built-in spectrophotometer. After measuring the baseline irradiances for both groups, the training group received detailed light-curing instructions and hands-on training with immediate visual feedback using the patient simulator. The irradiance of the training group was re-measured after the training. Both groups then attended a 26-day preclinical course, which involved placing 30 composite restorations. Upon completion of this course, the light-curing performance of both groups was re-assessed. The data were statistically analyzed using the Wilcoxon signed-rank test, Friedman’s ANOVA, and the Mann-Whitney U-test at an overall level of significance of α = 0.05. At baseline, the control and the training group delivered statistically similar irradiances with similar data scattering. In the training group, data scattering was considerably reduced after the hands-on training with the patient simulator. After the 26-day preclinical course, the irradiance of the training group was significantly higher and considerably less scattered compared to the control group. In conclusion, training with the patient simulator improved the light-curing performance of the dental students, mainly by helping them to deliver light energy more consistently.

Degree of Conversion and Polymerization Shrinkage of Bulk-Fill Resin-Based Composites

2017 ◽  
Vol 42 (1) ◽  
pp. 82-89 ◽  
Author(s):  
P Yu ◽  
AUJ Yap ◽  
XY Wang
Keyword(s):  
Light Emitting Diode ◽  
Degree Of Conversion ◽  
Attenuated Total Reflectance ◽  
Polymerization Shrinkage ◽  
Light Emitting ◽  
Significant Difference ◽  
Before And After ◽  
Light Curing ◽  
Curing Light ◽  
The Mean

SUMMARY This study evaluated the degree of conversion (DC) and polymerization shrinkage (PS) of contemporary bulk-fill resin-based composites (RBCs) including giomer materials. Two giomer bulk-fill (Beautifil Bulk Restorative [BBR], Beautifil Bulk Flowable [BBF]), two nongiomer bulk-fill (Tetric N-Ceram Bulk-fill [TNB], Smart Dentin Replacement [SDR]), and three conventional non–bulk-fill (Beautifil II [BT], Beautifil Flow Plus [BF], Tetric N-Ceram [TN]) RBCs were selected for the study. To evaluate the DC, disc-shaped specimens of 5-mm diameter and 2-mm, 4-mm, and 6-mm thickness were fabricated using customized Teflon molds. The molds were bulk filled with the various RBCs and cured for 20 seconds using a light-emitting diode curing light with an irradiance of 950 mW/cm2. The DC (n=3) was determined by attenuated total reflectance Fourier transform infrared spectroscopy by computing the spectra of cured and uncured specimens. PS (n=3) was measured with the Acuvol volumetric shrinkage analyzer by calculating specimen volumes before and after light curing. The mean DC for the various materials ranged from 46.03% to 69.86%, 45.94% to 69.38%, and 30.65% to 67.85% for 2 mm, 4 mm, and 6 mm, respectively. For all depths, SDR had the highest DC. While no significant difference in DC was observed between depths of 2 mm and 4 mm for the bulk-fill RBCs, DC at 2 mm was significantly greater than 6 mm. For the conventional RBCs, DC at 2 mm was significantly higher than at 4 mm and 6 mm. Mean PS ranged from 1.48% to 4.26% for BBR and BF, respectively. The DC at 2 mm and PS of bulk-fill RBCs were lower than their conventional counterparts. At 4 mm, the DC of giomer bulk-fill RBCs was lower than that of nongiomer bulk-fill materials.

scholarly journals Real-Time High-Level Acute Pain Detection Using a Smartphone and a Wrist-Worn Electrodermal Activity Sensor

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 3956
Author(s):  
Youngsun Kong ◽  
Hugo F. Posada-Quintero ◽  
Ki H. Chon
Keyword(s):  
Real Time ◽  
Electrodermal Activity ◽  
Smartphone Application ◽  
Real Time Processing ◽  
Pain Stimulation ◽  
Significant Difference ◽  
Before And After ◽  
Electrical Pulses ◽  
Pain Detection ◽  
High Level

The subjectiveness of pain can lead to inaccurate prescribing of pain medication, which can exacerbate drug addiction and overdose. Given that pain is often experienced in patients’ homes, there is an urgent need for ambulatory devices that can quantify pain in real-time. We implemented three time- and frequency-domain electrodermal activity (EDA) indices in our smartphone application that collects EDA signals using a wrist-worn device. We then evaluated our computational algorithms using thermal grill data from ten subjects. The thermal grill delivered a level of pain that was calibrated for each subject to be 8 out of 10 on a visual analog scale (VAS). Furthermore, we simulated the real-time processing of the smartphone application using a dataset pre-collected from another group of fifteen subjects who underwent pain stimulation using electrical pulses, which elicited a VAS pain score level 7 out of 10. All EDA features showed significant difference between painless and pain segments, termed for the 5-s segments before and after each pain stimulus. Random forest showed the highest accuracy in detecting pain, 81.5%, with 78.9% sensitivity and 84.2% specificity with leave-one-subject-out cross-validation approach. Our results show the potential of a smartphone application to provide near real-time objective pain detection.

scholarly journals Effects of delivering the same radiant exposures at 730, 1450, and 2920 mW/cm2 to two resin-based composites

2017 ◽  
Vol 11 (01) ◽  
pp. 022-028 ◽  
Author(s):  
Maan M. AlShaafi
Keyword(s):  
Fourier Transform ◽  
Degree Of Conversion ◽  
Attenuated Total Reflectance ◽  
Curing Time ◽  
Total Reflectance ◽  
Metal Rings ◽  
Significant Difference ◽  
Light Curing ◽  
Knoop Microhardness ◽  
Different Depths

ABSTRACT Objective: To evaluate the effects of curing two resin-based composites (RBC) with the same radiant exposures at 730, 1450, and 2920 mW/cm2. Materials and Methods: Two types of RBC, Filtek Supreme Ultra and Tetric-EvoCeram-Bulk Fill, were light-cured to deliver the same radiant exposures for 5, 10, or 20 s by means of a modified Valo light emitted diode light-curing unit with the light tip placed directly over each specimen. The RBC was expressed into metal rings that were 2.0 and 4.0 mm in thickness, directly on an attenuated total reflectance Fourier transform infrared plate heated to 33°C, and the degree of conversion (DC) of the RBC was recorded. The specimens were then removed and the Knoop microhardness (KHN) was tested at both the bottom and the top of each specimen. The KHN was tested again after 24 h and 7 days of storage in the dark at 37°C and 100% humidity. The DC and KHN results were analyzed with Fisher's protected least significant difference at α = 0.05. Results: The DC values for the specimens cured at the three different irradiance levels were similar. However, at different depths, there were differences in the DC values. In general, there were no clear differences among the samples cured in the three different groups, and the KHN was always greater 24 h and 7 days later (P < 0.05). Conclusions: Despite the curing time, and as long as the samples were cured with the same radiant exposures, there were no significant effects on the DC and KHN of both RBCs.

Marginal Adaptation of Direct Class II Composite Restorations with Different Cavity Liners

2013 ◽  
Vol 38 (6) ◽  
pp. E210-E220 ◽  
Author(s):  
R Pecie ◽  
I Onisor ◽  
I Krejci ◽  
T Bortolotto
Keyword(s):  
Elastic Modulus ◽  
Class Ii ◽  
Control Group ◽  
Shrinkage Stress ◽  
Marginal Adaptation ◽  
Composite Restorations ◽  
Significant Difference ◽  
Before And After ◽  
Group A ◽  
Group D

SUMMARY The aim of this study was to evaluate how cavity linings with different elastic modulus can influence the marginal adaptation (MA) of Class II composite restorations before and after thermo-mechanical loading. Materials and Methods: Forty Class II cavities with margins extending 1 mm below the cement-enamel junction were prepared in extracted human third molars. In each group except the control group, a lining material of 1-mm thickness was applied to the bottom of the cavity and polymerized before placing the resin composite Herculite XRV Ultra (group A: control; group B: Premise Flowable lining; group C: Herculite XRV Ultra lining; and group D: Optibond FL lining). MA was evaluated (with a scanning electron microscope) before and after loading (200,000 loading cycles). Statistical analysis was done using the Shapiro-Wilks test, the analysis of variance test, and Duncan post hoc test at p&lt;0.05. Results: Before loading, the percentages of continuous margins in dentin were superior (p&lt;0.05) for groups C and D (71.1% and 87.2%, respectively) compared to groups A and B (55.7% and 48.3%, respectively). After loading, group D (79.8%) was statistically superior in dentin compared to all of the other groups (43.6%, 35.9%, and 54.4%, respectively). In occlusal enamel, no significant difference was found between groups. The percentage of enamel fractures and the percentage of noncontinuous margins in proximal enamel were high, with no significant difference between liners. It can be concluded that for the materials used in this study, a 1-mm-thick lining with an extremely low elastic modulus (2-3 GPa) could redistribute shrinkage stress. The use of a flowable composite did not significantly improve MA.

The Effect of Interincisal Opening, Cavity Location and Operator Experience on the Energy Delivered by a Light-Curing Unit to a Simulated Dental Restoration

2014 ◽  
Vol 3 (2) ◽  
pp. 26-31 ◽  
Author(s):  
Nor Asilah Harun ◽  
Ario Santini ◽  
Elizabeth M Roebuck
Keyword(s):  
Total Energy ◽  
Mouth Opening ◽  
Nonparametric Test ◽  
Dental Restoration ◽  
Clinical Environment ◽  
Patient Simulator ◽  
Operator Experience ◽  
Second Molar ◽  
Significant Difference ◽  
Light Curing

Background Curing of resin-based composites depends on the delivery of adequate total energy, which may be operator dependent. Aim To determine the effect of interincisal opening, cavity location and operator experience on the total energy delivered to simulated cavity preparation sites. Design Three cohorts were included: junior dental nurses, senior dental nurses and qualified dentists (N=5, each cohort). Each operator (participant) followed the same procedure and light-cured two simulated restorations in a MARC® patient simulator using a Demi™ light-curing unit for 20 seconds in each of the following situations: left upper second molar (UL7), interincisal opening at both 25mm and 45mm; upper central incisor (UR1), interincisal opening at 45mm. The light energy delivered by each operator in each situation was recorded. Five readings for each operator were taken at each interincisal distance. Statistical comparisons of delivered energy (J/cm2) between interincisal openings, location and groups in the total energy delivered were performed using the Kruskal-Wallis nonparametric test: α=0.05. Results Less total energy was delivered to the posterior cavity at 25mm (12.0 ± 5.3J/cm2) than at 45mm (16.9 ± 5.6J/cm2) by all operators ( P<0.05). At 45mm, less total energy was delivered to the posterior cavity compared to the anterior cavity (25.1 ± 7.4J/cm2; P<0.05). There was no statistically significant difference between junior nurses and qualified dentists ( P>0.05) but there was a significant difference in the total energy delivered between senior nurses (20.1 ± 7.8J/cm2) and junior nurses (17.5 ± 7.6J/cm2) and between senior nurses and qualified dentists (16.6 ± 8.7J/cm2) ( P<0.05). Conclusions Interincisal mouth opening, location of the cavity and operator experience affected the total energy delivered to cavities in a simulated clinical environment.

scholarly journals Evaluation of Light-curing Intensity Output and Students’ Knowledge among Dental Schools in Riyadh City

2020 ◽  
Vol 8 (D) ◽  
pp. 178-181
Author(s):  
Sultan Binalrimal ◽  
Sarah Alamry ◽  
Mona Alenezi ◽  
Nora Alfassam ◽  
Sara Almuammar
Keyword(s):  
Light Intensity ◽  
Statistical Significance ◽  
Light Output ◽  
Dental Students ◽  
University Hospital ◽  
Dental School ◽  
Tooth Pulp ◽  
Riyadh City ◽  
Significant Difference ◽  
Light Curing

AIM: The aim of this study is interpreting the dental student’s knowledge of light-curing units from different universities and colleges in Riyadh city and to evaluate the intensity of the light output of light-emitting diode (LED)-curing devices in dental school clinics in Riyadh, Saudi Arabia. METHODS: One hundred eighty-two visible light-curing (VLC) units were randomly selected to have their light intensity output evaluated using Demetron® L.E.D. Radiometer – Kerr among dental school clinics in Riyadh city. The university hospitals we visited are King Khalid University Hospital, King Saud bin Abdulaziz University Hospital, Dar Al Uloom University Hospital, Alfarabi colleges’ dental clinics, and Princess Nourah Bint Abdulrahman University Hospital. To evaluate the knowledge of dental students about light intensity output, a questionnaire was given to the students. RESULTS: Out of the VLC units, 22 units (12%) measured inadequate intensity, 91 units (50%) measured marginal intensity, and 69 (37%) measured adequate intensity. The statistical significance was up to p < 0.05, p = 0. Most students and interns did not think that light-curing unit intensity influenced the tooth pulp (55.8%) and also reported not know the minimum wavelength of light cure intensity (62%). CONCLUSION: A significant difference was found between the light cure intensities in universities. As for the students’ knowledge, the research revealed poor insight toward basic concepts of VLC units and its maintenance.

Fracture Resistance and Marginal Adaptation of Capped and Uncapped Bulk-fill Resin-based Materials

2020 ◽  
Vol 45 (2) ◽  
pp. E43-E56
Author(s):  
HN Al-Nahedh ◽  
Z Alawami
Keyword(s):  
Fracture Resistance ◽  
Resin Composite ◽  
Testing Machine ◽  
High Viscosity ◽  
Significance Level ◽  
Capping Layer ◽  
Composite Restorations ◽  
Significant Difference ◽  
Light Curing ◽  
One Way Anova

SUMMARY Objectives: This study tested the fracture resistance of capped and uncapped bulk-fill composite restorations and compared them to a conventional composite. Also, the effect of different radiant exposure was investigated. Methods and Materials: Flowable and high-viscosity bulk-fill composites (SureFil SDR, Filtek Bulk-Fill Posterior, and Tetric N-Ceram Bulk-Fill) and a nanohybrid resin composite (Filtek Z350 XT) were used. Standardized class II cavities were prepared on extracted premolars, and different restoration protocols were used. In protocol 1 (control), restoration was applied using a layering technique; in protocol 2, restoration was applied in bulk with a capping layer; in protocol 3, restoration was applied in bulk without a capping layer; and in protocol 4, restoration was applied in bulk without a capping layer, and the light curing time was extended. After thermocycling, the restorations were examined for marginal gaps and then subjected to the fracture resistance test using a universal testing machine. Statistical analysis was carried out using two-way analysis of variance (ANOVA) followed by one-way ANOVA at a significance level of α = 0.05. Results: A statistically significant difference in the fracture resistance of the tested materials and protocols was detected. Filtek Bulk-Fill Posterior achieved the highest fracture resistance values regardless of the protocol used, and its results were comparable to those of Filtek Z350. SDR and Tetric N-Ceram Bulk-Fill achieved their highest strengths when a capping layer was added. Tetric N-Ceram Bulk-Fill showed improvement in fracture resistance with extended light curing, while SDR and Tetric N-Ceram Bulk-Fill achieved similar results with the addition of a capping layer. The uncapped bulk-fill group showed more gap-free margins than the capped group. Conclusion: The new high-viscosity bulk-fill composite restorations seem to have adequate fracture resistance. However, the results are material dependent, and some materials perform better with a capping layer and extended light curing.

scholarly journals Perception of Dental students regarding Periodontology education environment after curricular changes

2019 ◽  
Vol 9 ◽  
pp. 1-17
Author(s):  
Carla Andreotti Damante ◽  
Mariele Vertuan ◽  
Iago Amantéa Hallgren ◽  
Mariana Schutzer Ragghianti Zangrando
Keyword(s):  
Undergraduate Students ◽  
Social Relations ◽  
Weighted Average ◽  
Dental Students ◽  
Five Dimensions ◽  
Education Environment ◽  
Significant Difference ◽  
Before And After ◽  
Student’S T ◽  
Current Curriculum

The perception of Periodontology learning environment was measured before and after curricular restructuring by the Dundee Ready Education Environment Measure (DREEM). Undergraduate students (2nd, 3rd, 4th years; n = 266) were divided into two main groups: former curriculum (n = 131) and current one (n = 131). Total DREEM score, its five dimensions, Periodontology grades and their weighted average were compared. Student’s t test and ANOVA were used for analysis (p < 0.05). There was a statistically significant difference between the second (teachers) and fifth (social relations) dimensions and between Periodontology grades and the weighted average in both curricula. For each year, higher scores in the second dimension, Periodontology grades and the weighted average were obtained for current curriculum. Both curricula presented a significant correlation between Periodontology grades and their weighted average. Total DREEM scores for 2nd, 3rd and 4th years of current curriculum presented no differences (p > 0.05). The implementation of a new curriculum had an important impact on the students’ positive perceptions, which reflected in their academic performance

scholarly journals Edukasi Program Posyandu dimasa Pandemi Covid-19 sebagai Upaya Membentuk Persepsi Masyarakat di Wilayah Kerja Posyandu Cempaka Kelurahan Kuin Selatan Kota Banjarmasin

2021 ◽  
Vol 3 (2) ◽  
pp. 159
Author(s):  
Norfai Norfai ◽  
Eddy Rahman ◽  
Abdullah Abdullah
Keyword(s):  
Health Workers ◽  
Local Public Health ◽  
The Public ◽  
Under Five ◽  
Work Area ◽  
Significant Difference ◽  
Before And After ◽  
Service Activity ◽  
Power Point ◽  
And Training

The purpose of this service activity is to increase public knowledge, especially mothers who have babies or children under five years (balita), about the posyandu program. Before starting counseling, a questionnaire was filled (pretest). Counseling uses power point media with the lecture, discussion and question and answer method, then after being given counseling, the same questionnaire was distributed again to be filled back (posttest), after the knowledge data before and after counseling had been obtained, then the data were analyzed using the Wilcoxon statistical test.Based on the results of community service activities in the work area of the Banjarmasin Kuin Selatan Village Cempaka Posyandu, it means that there is a significant difference in knowledge between before and after counseling using power point media, thus it can be concluded that the method of extension using power point media carried out in the work area of the Banjarmasin Kuin Selatan Village Cempaka Posyandu is able and successful in increasing the knowledge of mothers who have chldren under five years. It is recommended that the local public health service (puskesmas) can provide more intensive guidance and training to posyandu cadres, so that they can assist health workers in educating the public about health in general and information about the importance of posyandu and the activities at the posyandu itself as an effort to participate forming a positive perception of the posyandu

Sign in / Sign up

Export Citation Format

Share Document