scholarly journals Influence of toothbrushing on enamel softening and abrasive wear of eroded bovine enamel: an in situ study

2006 ◽  
Vol 20 (2) ◽  
pp. 148-154 ◽  
Author(s):  
Daniela Rios ◽  
Heitor Marques Honório ◽  
Ana Carolina Magalhães ◽  
Marília Afonso Rabelo Buzalaf ◽  
Regina Guenka Palma-Dibb ◽  
...  
Keyword(s):  
Abrasive Wear ◽  
The Other ◽  
In Situ Study ◽  
Significant Difference ◽  
The Mean ◽  
Student’S T ◽  
Bovine Enamel ◽  
Enamel Layer ◽  
Student’S T Test

This study assessed the surface softening and abrasive wear of eroded bovine enamel with or without the influence of toothbrushing. Five volunteers took part in this in situ study of 5 days. They wore acrylic palatal appliances containing 6 bovine enamel blocks divided in two rows with 3 blocks, which corresponded to the studied groups: erosion without toothbrushing (GI) and erosion with toothbrushing (GII). The blocks were subjected to erosion by immersion of the appliances in a cola drink for 10 minutes, 4 times a day. After that, no treatment was performed in one row (GI), whereas the other row was brushed (GII). The appliance was then replaced into the mouth. Enamel alterations were determined using profilometry and microhardness tests. Data were tested using paired Student’s t test (p < 0.05). The mean wear values (µm) and percentage of superficial microhardness change (%SMHC) were respectively: GI - 2.77 ± 1.21/91.61 ± 3.68 and GII - 3.80 ± 0.91/58.77 ± 11.47. There was a significant difference in wear (p = 0.001) and %SMHC (p = 0.001) between the groups. It was concluded that the wear was more pronounced when associated to toothbrushing abrasion. However, toothbrushing promoted less %SMHC due to the removal of the altered superficial enamel layer.

scholarly journals THE RELIABILITY OF THE BOLTON RATIO WHEN APPLIED TO THE INDONESIAN POPULATION

2017 ◽  
Vol 10 (10) ◽  
pp. 176
Author(s):  
Joko Kusnoto
Keyword(s):  
T Test ◽  
Tooth Size ◽  
Crown Width ◽  
Indonesian Population ◽  
Significant Difference ◽  
The Mean ◽  
Anterior Ratio ◽  
Overall Ratio ◽  
Student’S T ◽  
Student’S T Test

  Objective: The objective of this study is to determine whether Bolton ratio can be applied clinically to the Indonesian population and to determine a more suitable Bolton ratio for the Indonesian population.Methods: This study was conducted on 120 readily available study models of treated cases comprising 37 males and 83 females. Two investigators separately measured the mesiodistal crown width of maxillary and mandibular tooth on each study model using sliding calipers. According to Bolton’s method, the overall and anterior ratios from each sample were calculated and the mean was generated. Using Student’s t-test with a 95% confidence interval, the investigators compared whether there is a significant difference between the ratio from Bolton’s samples and the ratio from the Indonesian samples.Results: The result of this study showed that, for Indonesian samples, the overall ratio is 89.7±2.05, while the anterior ratio is 76.4±2.76. Student’s t-test showed that there is a statistically significant difference (p<0.05) between the results of this study and that of Bolton’s study for both the anterior and overall ratios.Conclusion: It can be concluded that there is a difference between Indonesian population and Caucasian population in tooth size and Bolton ratio value. Therefore, original Bolton ratio value cannot be used as an accurate diagnostic tool for Indonesian population.

scholarly journals Inhibition of Demineralization at Restoration Margins of Z100 and Tetric EvoCeram Bulk Fill in Dentin and Enamel

2019 ◽  
Vol 6 (2) ◽  
pp. 36
Author(s):  
Cristina Leon-Pineda ◽  
Kevin Donly
Keyword(s):  
Light Microscopy ◽  
Polarized Light ◽  
In Vitro Study ◽  
The Other ◽  
Solution Ph ◽  
Class V ◽  
The Mean ◽  
Student’S T ◽  
Student’S T Test

Recurrent caries is still considered the main reason restorations need to be replaced. There are different materials available now that promise to reduce the possibility of recurrent caries by releasing fluoride and inhibiting restoration marginal caries. The purpose of this in vitro study was to evaluate the demineralization inhibition potential of a non-fluoride-releasing resin (Z100TM 3M, St. Paul, MN, USA) and a glass containing resin-based composite (Tetric EvoCeram Bulk Fill, Ivoclar/Vivadent AG, Schaan, Liechtenstein), which contains fluoride. Class V preparations were placed on 22 premolars; the gingival margin was below the cementoenamel junction and the occlusal margin was placed above the cemento-enamel junction. Ten teeth were randomly selected to be restored with Z100 while the other 10 were restored with Tetric EvoCeram Bulk Fill. Both groups were restored following manufacturer’s instructions. All teeth had an acid resistant varnish placed within one millimeter of the preparation margins. Both groups were placed in artificial caries challenge solution (pH 4.4). At the end of the 4 days; 100 µm buccolingual sections were obtained for each tooth; these were photographed under polarized light microscopy and the demineralized areas adjacent to the restorations were measured and quantified. The mean (±S.D.) area (µm2) of demineralization from the occlusal margin (enamel) and dentin margin were: Z100 2781.889 ± 1045.213; 3960.455 ± 705.964 and for Tetric EvoCeram Bulk Fill 1541.545 ± 1167.027; 3027.600 ± 512.078. Student’s t-test indicated that there was significantly less enamel and dentin demineralization adjacent to Tetric EvoCeram Bulk Fill compared to Z100; there was significantly less demineralization in enamel compared to dentin in both Tetric EvoCeral Bulk Fill and Z100. Tetric EvoCeram Bulk Fill performed better inhibiting demineralization at restoration margins when compared to Z100 and provided better demineralization inhibition in enamel than cementum/dentin.

scholarly journals Microsurgical clipping in forty patients with unruptured anterior cerebral circulation aneurysms: an investigation into cognitive outcome

2010 ◽  
Vol 68 (5) ◽  
pp. 770-774 ◽  
Author(s):  
Arthur A Pereira-Filho ◽  
Adriana G Pereira ◽  
Mário B Faria ◽  
Leonardo C.S Lima ◽  
Mirna W Portuguez ◽  
...  
Keyword(s):  
Mmse Score ◽  
T Test ◽  
Cognitive Outcome ◽  
Consecutive Series ◽  
Microsurgical Clipping ◽  
Unruptured Intracranial Aneurysms ◽  
Significant Difference ◽  
The Mean ◽  
Student’S T ◽  
Student’S T Test

OBJECTIVE: It is a consensus that most unruptured intracranial aneurysms (UIA) can be treated with acceptably low morbidity. However, some studies recently reported postoperative cognitive impairment, suggesting that it could be attributable to surgical damage. Our goal is to evaluate cognitive function before and after microsurgical clipping in patients with UIA. METHOD: A consecutive series of 40 patients who underwent microsurgical clipping for UIA were studied. The cognitive assessment (Mini Mental State Examination, MMSE) was performed immediately before and at least one month after surgery. Paired Student's "t" test and analysis of variance (ANOVA) were used for statistical purposes. RESULTS: The mean MMSE score in the preoperative analysis was 28.12 (SD, 1.34). In the postoperative period the mean MMSE score was 28.40 (SD, 1.46). Paired Student's "t" test was applied to the scores and no significant difference was found (p=0.315). ANOVA did not find independent associations between MMSE scores and age, hypertension, smoking, dyslipidemia, education, aneurysm location, number, laterality or size. CONCLUSION: The present study suggests that microsurgical clipping for UIA does not result in major cognitive dysfunction as determined by the MMSE

scholarly journals URINARY STONE RISK PROFILE IN STONE FORMER PATIENT

2015 ◽  
Vol 22 (2) ◽  
Author(s):  
Tommie Prasetyo ◽  
Ponco Birowo ◽  
Nur Rasyid
Keyword(s):  
Normal Population ◽  
Potassium Phosphate ◽  
Urinary Stone ◽  
Significant Difference ◽  
Stone Former ◽  
Calcium Magnesium ◽  
The Mean ◽  
Magnesium Oxalate ◽  
Student’S T ◽  
Student’S T Test

Objective: We were comparing the urinary stone risk profiles in stone former subjects group with normal population (non stone-former) group. Material & method: In this study, each group consist of 10 subjects. Urine samples used was a 24-hour-urine. All subjects in this study were previously informed and voluntarily participating. Inclusion criteria in this study were adult, stone free, residing in Jakarta. Measurement was performed in Department of Molecular Biology and Biochemistry Faculty of Medicine Indonesia University. Statistical analysis was performed using SPSS 20 (Chicago, USA) with Student’s t-test or Mann-Whitney (p < 0.05 was considered significant). Results: There was a significant difference in the mean age of two groups with no significant difference in weight and height. Significant difference (p < 0.05) in urinary profile was found in urea, uric acid, chloride, potassium, phosphate, and ammonia. Conversely, we found no significant differences (p > 0.05) in sodium, creatinine, calcium, magnesium, oxalate, and citrate levels. Conclusion: There were no significant differences in urinary stone promoting and inhibiting factors between two groups. Bigger number of sample size with better sampling method must be conducted for future studies.

Rate nephelometry and radial immunodiffusion compared for measuring serum prealbumin.

1987 ◽  
Vol 33 (1) ◽  
pp. 161-163 ◽  
Author(s):  
B M Goldsmith ◽  
S Munson
Keyword(s):  
Correlation Coefficient ◽  
Reference Interval ◽  
T Test ◽  
Radial Immunodiffusion ◽  
Healthy Children ◽  
Nephelometric Method ◽  
Significant Difference ◽  
The Mean ◽  
Student’S T ◽  
Student’S T Test

Abstract We compared a rate-nephelometric method and a radial immunodiffusion (RID) assay for measurement of prealbumin (transthyretin) in 55 samples of serum from healthy children. The mean prealbumin concentration as measured by the Beckman Auto ICS nephelometer was 188 mg/L (range 128-350); the mean by RID was 221 mg/L (range 125-419). This difference was statistically significant by Student's t-test (p less than 0.05), but the correlation coefficient (r) was 0.95. To determine a reference interval for prealbumin in children by the Auto ICS method, we assayed samples from 93 healthy children between the ages of one day and 18 years (55 boys, 38 girls). The mean was 191 mg/L, the reference interval (mean +/- 2 SD) 109-273 mg/L. There was no significant difference in prealbumin concentrations between girls and boys (Student's t-test, p greater than 0.05). Evidently the Beckman Auto ICS method measures prealbumin in serum rapidly and accurately.

Does the Ambulance Environment Adversely Affect the Ability to Perform Oral Endotracheal Intubation?

1996 ◽  
Vol 11 (2) ◽  
pp. 141-143 ◽  
Author(s):  
John E. Gough ◽  
Stephen H. Thomas ◽  
Lawrence H. Brown ◽  
James E. Reese ◽  
C. Keith Stone
Keyword(s):  
Endotracheal Intubation ◽  
Emergency Medical Technicians ◽  
Significant Difference ◽  
The Mean ◽  
Student’S T ◽  
Restrictive Environment ◽  
Injured Patients ◽  
First Time ◽  
Mean Time ◽  
Student’S T Test

AbstractObjective:Oral endotracheal intubation (ETI) is the preferred method of controlling the airway in critically ill or injured patients. It was postulated that time could be saved if intubation was performed in the ambulance en route to the hospital. This study was designed to determine whether the ambulance environment adversely affected the ability of emergency medical technicians at the advanced-intermediate level (EMT-AI) to perform oral ETI.Hypothesis:The restrictive environment of a moving ambulance would affect adversely the ability of EMT-AIs to perform ETI compared with a controlled setting. This would result in a significant increase in the time necessary to perform ETI in the ambulance compared with a controlled setting not complicated by restrictive space and motion.Methods:Twenty on-duty EMT-AIs were recruited to volunteer for this prospective, nonrandomized, nonblinded trial. All participants performed three consecutive oral ETIs on an airway mannequin in two settings: 1) in the back of a moving ambulance; and 2) on a table in the rescue squad station. Of the participants, 10 performed the intubations in the ambulance first; the remainder performed the intubations at the station first. Time for intubation with the mannequin was recorded by stopwatch. The mean times for intubation in both settings were compared by Student's t-test (p<0.05).Results:All intubation attempts were successful. The mean time for intubation in the station was 13.0±3.4 seconds. The mean time in the ambulance setting was 13.2±5.3 seconds. There was no significant difference between the intubation times in the two settings (p = 0.88).Conclusion:The environment of a moving ambulance does not appear to hinder the ability of EMT-AIs to perform oral ETI in a laboratory setting with a mannequin model.

scholarly journals Evaluation of the substantivity of chlorhexidine in association with sodium fluoride in vitro

2003 ◽  
Vol 17 (1) ◽  
pp. 78-81 ◽  
Author(s):  
Carolina Saliba de Freitas ◽  
Henrique França Oliveira Diniz ◽  
Jânderson Breder Gomes ◽  
Rubén Dário Sinisterra ◽  
María Esperanza Cortés
Keyword(s):  
Sodium Fluoride ◽  
Therapeutic Agents ◽  
Ultraviolet Region ◽  
Mean Values ◽  
The Mean ◽  
The Difference ◽  
Student’S T ◽  
Bovine Enamel ◽  
Student’S T Test

The efficacy of the fluoride-chlorhexidine association in the prevention of gingivitis and caries has been advocated for a number of years5,7,14. The objective of the association of these therapeutic agents is a synergistic action. The aim of the present study was to determine the substantivity of chlorhexidine associated or not to sodium fluoride at different intervals of time, in vitro. Bovine enamel surfaces were treated with 0.12% chlorhexidine gluconate (Periogard® - Colgate®) or 0.05% sodium fluoride with 0.12% chlorhexidine (Duplak® - Dentsply®) solutions for one minute. Fragments were placed in distilled water and samples were collected at intervals of 5, 30 and 360 minutes and analyzed by spectrophotometry in the visible ultraviolet region. Substantivity was evaluated by the measurement of chlorhexidine desorption from the treated slabs. The mean values obtained were statistically analyzed by Student's t-test. The results showed that the concentration of chlorhexidine decreased when it was used in association with sodium fluoride. The difference between the groups was statistically significant (p < 0.05). These in vitro results suggest that the association between sodium fluoride and chlorhexidine in the studied concentrations appears to have no beneficial effect because of the decrease in the substantivity of chlorhexidine.

Resin-Based Materials Protect Against Erosion/Abrasion—a Prolonged In Situ Study

2019 ◽  
Vol 44 (3) ◽  
pp. 302-311
Author(s):  
D Rios ◽  
GC Oliveira ◽  
CR Zampieri ◽  
MC Jordão ◽  
EJ Dionisio ◽  
...  
Keyword(s):  
Dental Erosion ◽  
Additional Treatment ◽  
The Other ◽  
Control Group ◽  
Material Loss ◽  
In Situ Study ◽  
Phase Study ◽  
And Control ◽  
Bovine Enamel

SUMMARY While patient compliance is key to preventive measures related to dental erosion, the application of resin-based materials could serve as an additional treatment to inhibit erosion progression. This in situ study evaluated the effect of applying resin-based materials, including resin infiltrant, on previously eroded enamel subjected to prolonged erosive and abrasive challenges. The factors under study were types of treatment (infiltrant [Icon], sealant [Helioseal Clear], adhesive [Adper Scotchbond Multi-Purpose Plus], and control [no treatment]); wear conditions (erosion [ERO] and erosion + abrasion [ERO + ABR]) and challenge time (5 and 20 days) in a single-phase study. The blocks were prepared from bovine enamel, eroded (0.01 M HCl, pH 2.3 for 30 seconds) and randomized among treatments, wear conditions, and volunteers. The application of resin-based materials followed the manufacturers' recommendations. Twenty-one volunteers wore the palatal intraoral device, in which one row corresponded to ERO and the other to ERO + ABR. In each row, all treatments were represented (2 blocks per treatment). For 20 days, the erosive challenge was performed 4 times/day (immersion in 0.01 M HCl, pH 2.3, for 2 minutes) for the ERO condition. For the ERO + ABR condition, two of the erosive challenges were followed by abrasion for 15 seconds with fluoride dentifrice slurry. Enamel and/or material loss was measured using profilometry (initial, after treatment, and after the end of the fifth and 20th days of in situ erosive challenge) and analyzed by ANOVA models and Tukey's test (α=0.05). The results showed that the application of resin-based materials did not cause superficial enamel loss. The infiltrant group showed a thicker layer of material above the enamel compared with the other materials (p=0.001). After the erosive challenge, there was no difference between the conditions ERO and ERO + ABR (p=0.869). All materials protected the enamel against erosion progression compared with the control group (p=0.001). Based on these results, we conclude that the application of resin-based materials results in protection of previously eroded enamel subjected to in situ erosive and abrasive challenge for 20 days.

scholarly journals The Effect of Stapedotomy on Tinnitus in Patients with Otospongiosis

2005 ◽  
Vol 84 (7) ◽  
pp. 412-414 ◽  
Author(s):  
Adriana da Silva Lima ◽  
Tanit Ganz Sanchez ◽  
Renata Marcondes ◽  
Ricardo Ferreira Bento
Keyword(s):  
Hearing Loss ◽  
Good Control ◽  
Analog Scale ◽  
Exact Test ◽  
Pure Tone Average ◽  
Significant Difference ◽  
The Mean ◽  
Student’S T ◽  
Air Conduction ◽  
Student’S T Test

Stapedotomy is primarily performed to treat hearing loss secondary to otospongiosis, although some patients find that the accompanying tinnitus is more bothersome than the hearing loss. We prospectively studied 23 consecutive patients with tinnitus secondary to otospongiosis who had undergone stapedotomy, and we compared their pre- and postoperative medical and audiologic findings. Patients annoyance with their tinnitus was quantified by means of a visual analog scale, and their air-conduction thresholds were determined by measurements of a 4-frequency pure-tone average (0.5, 1, 2, and 4 kHz). Statistical analysis was performed using the paired Student's t test and Fisher's exact test. In the group as a whole, the mean tinnitus annoyance visual analog scores were 8.34 preoperatively and 1.56 postoperatively, a highly significant difference. Clinically, 22 of the 23 patients (95.7%) achieved satisfactory control of their tinnitus (improvement or complete resolution) following stapedotomy. With respect to hearing loss, all patients clinically improved postoperatively, and audiometry confirmed improvement at all 4 frequencies between 0.5 and 4 kHz. An air-bone gap of less than 10 dB was noted in 17 patients (73.9%). We conclude that in addition to improving hearing, stapedotomy also provides good control of tinnitus.

scholarly journals Evaluation of the reliability of measurements in cephalograms generated from cone beam computed tomography

2013 ◽  
Vol 18 (4) ◽  
pp. 53-60 ◽  
Author(s):  
Maurício Barbosa Guerra da Silva ◽  
Bruno Cabús Gois ◽  
Eduardo Franzotti Sant'Anna
Keyword(s):  
Computed Tomography ◽  
Three Dimensional ◽  
The Other ◽  
Cone Beam ◽  
Perspective Projection ◽  
Linear Measurements ◽  
Significant Difference ◽  
Angular Measurements ◽  
Student’S T ◽  
Student’S T Test

OBJECTIVE: The purpose was to compare angular and linear measurements generated in digital cephalometric radiographs and cephalograms synthesized from three-dimensional images. METHODS: Twenty-six individuals (12 men and 14 women) with mean age of 26.3 years were selected. Digital cephalometric radiographs and CBCTs were taken on the same day. The images were imported and analyzed on Dolphin Imaging V.10.5 software, which synthesized cephalograms in perspective projection and magnification of 9.7%. A single observer marked the points and repeated the procedure with an interval of time of ten days to evaluate intraexaminer error. In the statistical analysis paired Student's t test was used to establish the correlation between the measurements. RESULTS: The angular measurements GoGn.SN and IMPA, which involved the Gonial point (Go) and the linear measurements that involved the lips presented significant difference (p < 0.05). The other measurements presented good correlation. CONCLUSION: The measurements in the synthesized cephalograms proved to be reliable.

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