scholarly journals Enamel Surface Roughness after Lingual Bracket Debonding: An In Vitro Study

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4196
Author(s):  
Martina Eichenberger ◽  
Anna Iliadi ◽  
Despina Koletsi ◽  
George Eliades ◽  
Carlalberta Verna ◽  
...  

The aim of the present study was to quantitatively assess changes in enamel roughness parameters before and after lingual bracket debonding. The lingual surface of 25 sound premolars extracted for orthodontic reasons was studied by 3D optical interferometric profilometry before and after debonding of lingual brackets following enamel finishing (with fine diamond) and polishing (with 12- and 20-fluted carbide burs). The roughness parameters tested were the amplitude parameters Sa and Sz, the hybrid parameter Sdr, and the functional parameters Sc and Sv. The parameter differences (after debonding-reference) were calculated, and statistical analysis was performed via a Wilcoxon signed-rank test. Statistically significantly higher values were observed in all the surface roughness parameters of enamel surfaces after finishing and polishing, with the mostly affected parameter being the Sdr. Under the conditions of the present study, the finishing and polishing instruments used after debonding of lingual noncustomized brackets created a surface texture rougher than the control in all the tested roughness parameters.

2021 ◽  
Vol 11 (18) ◽  
pp. 8543
Author(s):  
Asaf Shely ◽  
Shiri Livne ◽  
Gil Ben-Izhack ◽  
Michal Lokshin ◽  
Shahar Har-Nes ◽  
...  

Background: The purpose of this in vitro study was to compare the implant axis’ spatial position and orientation by using laboratory scanner versus intra-oral scanner with three different scan abutments. Methods: A 3D model was printed with an internal hex implant analog in the place of teeth 35#. Three standard scan abutments were used: MIS (two-piece titanium), AB (two-piece PEEK and titanium base) and ZZ (one-piece PEEK). Each scan abutment was scanned 30 times by TRIOS E3 (laboratory scanner) and 30 times by Omnicam (intra-oral scanner). For each scan, an STL (stereolithography) file was created, and the spatial characterization of each scan abutment was measured in the X, Y, Z coordinates, and rotational and longitudinal angles. The comparison between all the scans was conducted by superimposition of the STL files, using a 3D software. A t-test and Wilcoxon signed-rank test were used. (p < 0.05) Results: Only the MIS scan abutment showed no statistical difference in the X and Z axes. (p < 0.05). All other scan abutments showed a statistical difference in all axes. The rotational angle of the AB scan abutment was twice the angle of the MIS and ZZ scan abutments. Conclusions: All three scan abutments showed a rotational deviation of the implant axis between the laboratory scanner and the intra-oral scanner. The AB scan abutment showed the greatest deviation (1.04 degrees) while the other two abutments showed deviations of about half a degree in relation to the laboratory scan abutment. There is a need for further studies which will examine the influence of geometry, material, and scan abutment parts on the accuracy of the scan obtained.


2021 ◽  
Vol 11 (11) ◽  
pp. 5161
Author(s):  
Christina Kühne ◽  
Ulrich Lohbauer ◽  
Stefan Raith ◽  
Sven Reich

This in-vitro study aimed to investigate whether intraoral scanners (IOS) are suitable for wear measurement compared to optical profilometry (WLP). A zirconia cast representing the teeth (24–28) was fabricated. It was digitized six times using three different intraoral scanners, Cerec Omnicam AC (OC), Trios 3 (Tr3), and True Definition (TD). The scans were conducted at baseline (t0) and at three different stages of simulated wear (t1–t3), each at one wear-facet on FDI 26 and FDI 27. WLP was used as a reference method. Within each acquisition system, the maximum wear at each facet was analyzed by superimposing the STL data of t0 with t1–t3. A power analysis was performed (G*Power), and the Wilcoxon-signed-rank-test was used to evaluate whether there were statistically significant differences between the groups (Bonferroni corrected) (α = 0.05). At wear-facet FDI 27, differences from +4% t1 TD up to +19% t2 OC, corresponding to a metric value of 8 µm and 45 µm, were measured. At FDI 26 deviations between −2% t1 Tr3, and +10% OC and Tr3, were observed. Considering some limitations, the IOS are a promising alternative to wear measurement based on WLP due to its simple application to capture surface changes in a reasonable and quick way.


2016 ◽  
Vol 41 (3) ◽  
pp. E73-E82
Author(s):  
H Redwan ◽  
DN Bardwell ◽  
A Ali ◽  
M Finkelman ◽  
S Khayat ◽  
...  

SUMMARY Objective: The aim of this study was to evaluate the microleakage of the composite restorations when bonded to tooth structure previously restored with amalgam material compared with that of freshly cut dentin. Methods and Materials: Thirty intact, extracted intact human molars were mounted in autopolymerizing acrylic resin. Class II box preparations were prepared on the occluso-proximal surfaces of each tooth (4-mm bucco-lingual width and 2-mm mesio-distal depth) with the gingival cavosurface margin 1 mm above the CEJ. Each cavity was then restored using high copper amalgam restoration (Disperalloy, Dentsply) and then thermocycled for 10,000 thermal cycles. Twenty-five of the amalgam restorations were then carefully removed and replaced with Filtek Supreme Ultra Universal (3M ESPE); the remaining five were used for scanning electron microscopy and energy dispersive x-ray spectroscopy analysis. A preparation of the same dimensions was performed on the opposite surface of the tooth and restored with composite resin and thermocycled for 5000 thermal cycles. Twenty samples were randomly selected for dye penetration testing using silver nitrate staining to detect the microleakage. The specimens were analyzed with a stereomicroscope at a magnification of 20×. All of the measurements were done in micrometers; two readings were taken for each cavity at the occlusal and proximal margins. Two measurements were taken using a 0-3 scale and the percentage measurements. Results: Corrosion products were not detected in either group (fresh cut dentin and teeth previously restored with amalgam). No statistically significant difference was found between the microleakage of the two groups using a 0-3 scale at the occlusal margins (McNemar test, p=0.727) or proximal margins (Wilcoxon signed-rank test, p=0.174). No significance difference was found between the two groups using the percentage measurements and a Wilcoxon signed-rank test at either the occlusal (p=0.675) or proximal (p=0.513) margins. However, marginal microleakage was statistically significant between the proximal and occlusal margins (p&lt;0.001). Conclusion: Within the limitations of this in vitro study, no significant difference was found between the microleakage of nondiscolored dentin in teeth that were previously restored with amalgam compared with freshly cut dentin. However, marginal microleakage in the proximal surface was higher than that in the occlusal surface.


Author(s):  
I Ketut Widana

The working practice of the engineering students is part of the learning process that is irreducible and indispensable. The composition of  lecturing between theoretical and practical one is 40% to 60%. With this condition, the students spend more time at the laboratory. Generally, the students perform in the laboratory work by standing position. The design of research is observational cross-sectional. The method applied is observation, interview and measuring. The subjects of research are practicing students amounting to 21 students. Referring to the analysis of statistical test or Wilcoxon signed ranks test, the difference of effect of work position is significant, namely p < 0.05 towards musculoskeletal disorders (MSDs) before and after working. The quantity of the average complaint after working is score 44.62 ± 9.47. The result of Wilcoxon signed rank test shows that there is significant different effects of standing work position, namely p < 0.05 towards fatigue generally before and after working. The degree of the working pulse is on the average of 110.78  ± 17.80 bpm (beats per minutes) which can be categorized into the medium workload. Using paired t-test, the result is p < 0.05.


2020 ◽  
Vol 1 (2) ◽  
pp. 1
Author(s):  
Nur Akmal Binti A'ffan ◽  
Reni Farenia ◽  
Delita Prihatni

A research has been done to compare the differences on the enzyme creatine phosphokinase (CPK) level and muscle soreness before and after 4-weeks swim practices on swimmers of College swimming club. Eighteen healthy male swimmers (mean ± SD; age: 19,94 ± 1,86 years; weight: 65,28 ± 6,14 kg; height: 1,72 ± 0,43 m) participated in this study. All subjects performed their 4-weeks swim practices which consist of 2x120 hours per week with 500 meters average daily swim distance and weight training. Blood was collected before and after the practices and CPK were analyzed. Questionnaires concerning muscle soreness were filled put before each blood draw. Results were analyzed using normality test and Wilcoxon signed rank test (p<0.05). There was significant increase in CPK level during 4-weeks swim practices by 59.41% (p=0.044). Whereas for muscle soreness (overall and specifically in arms and thighs), there was no significant differences between before and after the 4-weeks swim practices. As a conclusion, participation in 4-weeks swim practices resulted in significant serum CPK enzyme elevation, but there was lack of significance in muscle soreness differences on swimmers of College swimming club.


2018 ◽  
Vol 35 (4) ◽  
pp. 706-712 ◽  
Author(s):  
Anjana Srinivasan ◽  
Alex Al Khoury ◽  
Svetlana Puzhko ◽  
Carole Dobrich ◽  
Meira Stern ◽  
...  

Background: Infant tongue-tie can cause breastfeeding problems, which may be improved by frenotomy. However, controversy exists among the medical community. Research aim: To examine the influence of frenotomy on infants with posterior ankyloglossia, by quantifying the changes in breastfeeding and maternal nipple pain using standardized tools. Methods: Newborns ( N = 30) below 12 weeks of age were recruited from the Herzl–Goldfarb Breastfeeding Clinic between April 2014 and April 2015. Diagnosis of posterior ankyloglossia was made clinically. Frenotomy was performed. Mothers received breastfeeding counseling before and after the procedure. Pain and breastfeeding were assessed before the procedure, immediately after the procedure, and after 2 days, 7 days and 14 days. Breastfeeding was assessed using the LATCH Tool and by subjective questioning. Maternal nipple pain was assessed using the Numeric Rating System. Results: No complications were reported with frenotomy. There was a significant improvement in LATCH score immediately post-frenotomy, with an increase in median scores from 7.5 to 8.5 ( p < .0001, Wilcoxon signed rank test). There was a significant decrease in median pain score immediately post-frenotomy, from 3.0 on the left nipple and 3.25 on the right nipple, to 0 bilaterally ( p < .0001, Wilcoxon signed rank test). Subjective improvement in breastfeeding was reported by 90% of mothers immediately after frenotomy and 83% of mothers at Day 14. Conclusion: Frenotomy for posterior ankyloglossia may improve breastfeeding and nipple pain.


2019 ◽  
Vol 9 (4) ◽  
pp. 191-195
Author(s):  
S. C. Meribe ◽  
E. Harausz ◽  
I. Lawal ◽  
A. Ogundeji ◽  
C. Mbanefo ◽  
...  

Background: To improve rates of human immunodeficiency virus (HIV) case detection and treatment, the Nigerian Ministry of Defense Health Implementation Program and the US Army Medical Research Directorate-Africa/Nigeria introduced a HIV standard of care (SOC) package. Given the integration of tuberculosis (TB) and HIV programs and evolving policies, we evaluated the impact of this strategy on TB program indicators.Methods: Routine, de-identified program data from 27 Nigerian military hospitals were analyzed. Using Wilcoxon signed-rank test, bivariate analyses were performed to compare data from 12 months before and after implementation of the SOC package.Results: Our data showed improvements post-implementation as follows: the number of individuals receiving antiretroviral therapy (ART) screened for TB increased from 14 530 to 29 467 (P < 0.001); the number of individuals with presumptive TB identified increased from 803 to 1800 (P < 0.001); the number of ART clients bacteriologically tested for TB increased from 746 to 1717 (P < 0.001); and the number of ART clients treated for TB increased from 152 to 282 (P < 0.001). Newly registered or relapsed TB cases increased from 436 to 906 (P < 0.001), the number of TB cases with known HIV status increased from 437 to 837 (P < 0.001), the number of TB-HIV co-infected cases increased from 182 to 301 (P = 0.006), and the number of TB-HIV co-infected clients who started ART increased from 101 to 176 (P = 0.003).Conclusion: The implementation of the updated HIV SOC package led to the improvement in key TB diagnosis and treatment indicators. When emulated, this could help improve the performance of other TB programs in countries other than Nigeria.


Author(s):  
Anggita Langgeng Wijaya ◽  
Mia Noviyanti ◽  
Probo Mahayu

The purpose of this study was to test the market reaction to the announcement of the Sri Kehati Index on the Indonesia Stock Exchange. The population in this study is all companies included in the Sri Kehati Index from 2013 to 2016. The selection of samples was taken by the population sampling method. Hypothesis testing is done by paired t test and Wilcoxon Signed Rank Test. The findings of this research are: 1) there is no difference in abnormal returns before and after the announcement of the Sri Kehati Index on the Indonesia Stock Exchange. 2) There is a difference in the activity of stock trading volume before and after the announcement of the Sri Kehati index in the 5th and 6th periods, but there is no difference in the activity of stock trading volume in other periods. The Indonesia Stock Exchange did not react consistently to the announcement of the Sri Kehati Index.


2018 ◽  
Vol 12 (1) ◽  
pp. 89 ◽  
Author(s):  
Giyati Retnowati ◽  
Rose Mini Agoes Salim ◽  
Airin Y Saleh

This research aimed to determine the effectiveness of picture in storybook reading to increase kindness in children. This research involved 31 children aged 5-6 years; they were taken from the kindergarten in Bandung as the participants. The intervention was done by reading eight picture books in eight days. The kindness was measured using a measurement instrument created by the researcher, in the form of nine coloured cards that described the behaviour of kindness. The measurement was also done by seeing through the kindness tree and observation sheets that filled out by the teacher. The data analysis using the Wilcoxon Signed-rank test shows a significant difference in the average score of kindness (p<0,05) before and after picture storybook reading. Two weeks after the intervention, the improvement on all kindness behaviours with the post-test score is greater than pre-test score that still can be found. Observation through kindness tree and observational sheets shows the same result.


2021 ◽  
Vol 1 (2) ◽  
pp. 309-331
Author(s):  
Lisa Erliana Marwan ◽  
Iwan Setiawan ◽  
Ine Mayasari

Government policy through UU No 34 Thn 2014 about Hajj Fund Management said that the Hajj Fund Management should with the principle of sharia. Then in 2014, there was a transfer Hajj Fund from Conventional banks to Islamic banks. Hajj Fund that transferred to Islamic banks have a large value so it can give positive contribution to the  financial performance such as DPK.The aim of this study was to find out the financial performance of 6 BPS BPIH before and after the transfer of Hajj Fund from conventional banks to Islamic banks. Taking case studies at PT. Bank Syariah Mandiri, PT. Bank BRI Syariah, PT. Bank BNI Syariah, PT. Bank Mega Syariah, PT. Bank Panin Dubai Syariah, and PT. Bank Muamalat.  The Data that used in this study is Return On Assets (ROA) and Financing to Deposit Ratio (FDR) in Quarterly Financial Report of 6 BPS BPIH,4 years before the transfer of hajj fund that started 2010 until 2013, and 4 years after the transfer of hajj fund that started from 2015 until 2018. The method of data analysis in this study uses a different samples in non parametrik, which is Wilcoxon Signed Rank Test. The result of this  study  shows us that there was a difference in ROA and FDR of BPS BPIH before and after the transfer of  hajj  fund  from  conventional  banks  to Islamic banks.


Sign in / Sign up

Export Citation Format

Share Document