scholarly journals Effects of Light Activation, Agent Concentration, and Tooth Thickness on Dental Sensitivity After Bleaching

2013 ◽  
Vol 38 (5) ◽  
pp. 467-476 ◽  
Author(s):  
G Moncada ◽  
D Sepúlveda ◽  
K Elphick ◽  
M Contente ◽  
J Estay ◽  
...  

SUMMARY Examining three bleaching systems, this in vivo clinical trial evaluated the relationship among tooth sensitivity, light activation, and agent concentration, and it correlated dental sensitivity with tooth thickness. Materials and Methods: Eighty-seven volunteer patients were included. Inclusion criteria were the presence of anterior teeth without restorations as well as the absence of a previous bleaching experience and absence of noncarious cervical lesions or dental pain. Exclusion criteria included pregnancy or breastfeeding, a maximum of TF3 hypoplasia, tetracycline-fluorosis stains, malpositioned teeth, orthodontic treatment, periodontal disease, and/or analgesic/anti-inflammatory intake. Patients were randomly assigned to three bleaching groups: Group A (n=25) was treated with 15% H2O2 and nitrogenous-titanium-dioxide and was light activated (Lase Peroxide Lite, DMC, SaoCarlos, Sao Paulo, Brazil); Group B (n=27) was treated with 35% H2O2 and was light activated (Lase Peroxide Sensy, DMC); and Group C (n=35) was treated with 35% H2O2 (White Gold Office, Dentsply, 38West Clark Ave., Milford, USA) without light activation. Tooth sensitivity (TS) was self-reported by the patients using the visual analog scale (VAS) at baseline (TS0), immediately after treatment (TSI), and at seven days after treatment (TS7). In 46 patients, tooth thickness was determined by computed tomography. TS0, TSI, and TS7 were compared between the A and B groups to determine the effect of concentration and between the B and C groups to determine the effect of light using analysis of covariance. The correlation between tooth thickness and TSI was determined by Spearman Rho test (SPSS 15). Results: Eighty-seven patients were evaluated at baseline, and 61 were evaluated at seven days. Separated by groups, tooth sensitivity, expressed as VAS value at the time points TS0, TSI, and TS7, respectively, were as follows: Group A: 13.76 ± 13.53, 24.40 ± 25.24, and 5.94 ± 5.5; Group B: 15.07 ± 18.14, 42.4 ± 31.78, and 8.68 ± 17.99; and Group C: 10.80 ± 14.83, 31.51 ± 29.34, and 7.24 ± 9.2. Group A showed significantly lower tooth sensitivity than group B at TSI (p=0.032). No differences were observed in the tooth sensitivities between groups B and C. No correlation was encountered between tooth thickness and tooth sensitivity immediately after treatment (Rho=−0.088, p=0.563). The median tooth thickness was 2.78 ± 0.21 mm. Conclusions: Increases in the concentration of bleaching agents directly affect tooth sensitivity, and LED/laser activation and tooth thickness are not correlated with tooth sensitivity after dental bleaching.

2010 ◽  
Vol 11 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Qasem Alomari ◽  
Ehsan El Daraa

Abstract Aim The study aimed to evaluate the effect of four in-office dental bleaching methods on shade change, color stability, patient satisfaction and postoperative sensitivity. Methods and Materials Forty patients were randomly divided into four groups (n=10) according to the method of in-office bleaching used: Group A—35% hydrogen peroxide (HP); Group B—35% HP plus BriteSmile and a blue curing light; Group C—35% HP plus QuickSmile and an LED curing light; Group D—35% HP and a Zoom2 metal halide curing light. For all groups, there was only one session of bleaching with three 20-minute applications of bleaching gel. The shade was evaluated before bleaching, immediately after, and one month after treatment using a VITA Classical Shade Guide. Results Immediately after bleaching there was a significant difference in color change between the four groups, with Group B having the best results. At one month there was no difference between the four groups. Immediate postoperative sensitivity was the least in Group A and the highest for Group B. Patients in Group B were the most satisfied with the outcome of the bleaching procedure. Conclusions In general, the use of different lights for activation of an in-office bleaching agent did not affect the long-term results. Tooth sensitivity was mild and transient in the study. Patients were satisfied with in-office bleaching. Clinical Significance Using light activation with in-office bleaching seems to increase the efficacy of treatment only for a short period of time. Citation Alomari Q, Daraa EE. A Randomized Clinical Trial of In-Office Dental Bleaching with or without Light Activation. J Contemp Dent Pract [Internet]. 2010 Jan; 11(1):017-024. Available from: http://www.thejcdp.com/journal/view/volume11- issue1-alomari.


GYNECOLOGY ◽  
2018 ◽  
Vol 20 (6) ◽  
pp. 48-52
Author(s):  
E N Kravchenko ◽  
R A Morgunov

The aim of the study. Assess the importance of pregravid preparation and outcomes of pregnancy and childbirth, depending on the reproductive attitudes of women in the city of Omsk. Materials and methods. The study included 92 women who were divided into groups: group A (n=43) - women whose pregnancy was planned; group B (n=49) - women whose pregnancy occurred accidentally. Each group was divided into subgroups depending on age: from 18 to 30 and from 31 to 49 years. For each patient included in the study, a specially designed map was filled out. These patients were interviewed at the City Clinical Perinatal Center. Results. Comparative analysis revealed the relationship between the reproductive settings of women of childbearing age and the peculiarity of the course of pregnancy and childbirth in these patients. Summary. The majority of women of fertile age are married: in subgroup AA - 25 (96.2%), AB - 13 (76.5%), BA - 25 (92.6%), BB - 20 (91.0%). The predominant number of women of fertile age have one or more abortions: in subgroup AA - 12 (46.2%), AB - 6 (35.3%), in subgroups of comparison BA - 8 (29.6%), BB - 6 (27.3%). More than half of the women of fertile age surveyed have a history of untreated cervical pathology (from 40.8% to 64.7%). The course of pregnancy in women planning pregnancy in most cases proceeded without complications: in subgroup AA - 13 (50.0%), AB - 11 (64.7%). The most common cause of complicated pregnancy in women whose pregnancy occurred accidentally is the threat of spontaneous miscarriage: in subgroup BA - 15 (55.6%), BB - 16 (72.7%). The uncomplicated course of labor more often [subgroup AA - 19 (73.0%), AB - 12 (70.6%)] was observed in women whose pregnancy was planned and they were motivated to give birth to a healthy child.


2021 ◽  
Vol 15 (1) ◽  
Author(s):  
S. Samra ◽  
M. Habeb ◽  
R. Nafae

Abstract Background A few people infected by the coronavirus become seriously ill, while others show little to no signs of the symptoms, or are asymptomatic. Recent researches are pointing to the fact that the ABO blood group might play an important role in a person’s susceptibility and severity of COVID-19 infection. Aim of the study: try to understand the relationship between ABO groups and COVID-19 (susceptibility and severity). Results A total of (507) patients were included in this study. The study population was divided based on the ABO blood group into types A+, A−, B+, AB, O+, and O−. Blood group A was associated with high susceptibility of infection: group A, 381 (75.1%); and less common in group O, 97 (19.2%), group B, 18 (3.5%), and group AB, 11 (2.2%). The severity of COVID-19 infection was common in non-blood group O where (20 (7.1%), 4 (26.7%), 2 (11%), and 1 (9%) in type A+, A−, B+, and AB, respectively), while in type O 3.1%. And mechanically ventilated patients were 22 (5.9%), 2 (13.4%), 2 (11.1%), and 1 (1%). Mortality was high in blood groups A and B, 16 (4.37%) and 1 (5.5%), respectively, while in blood group O, it was 1%. Conclusion The incidence, severity, and mortality of COVID-19 were common in non-blood group O. While blood group O was protected against COVID-19.


2008 ◽  
Vol 57 (6) ◽  
pp. 709-716 ◽  
Author(s):  
T. I. I. van der Kooi ◽  
M. Koningstein ◽  
A. Lindemans ◽  
D. W. Notermans ◽  
E. Kuijper ◽  
...  

The first Dutch outbreak due to Clostridium difficile ribotype 027 was observed in mid-2005; by the end of that year, eight hospitals were affected. To study the relationship between hospital-wide antibiotic use and the incidence of 027-linked C. difficile-associated disease (CDAD) three study groups were made: group A, all eight hospitals with an 027-associated epidemic; group B, five of a total of six hospitals with occasional 027 cases, without an increase in CDAD; and group C, ten randomly selected hospitals with no reported 027 epidemics or isolated 027 cases. Quarterly data on CDAD incidences, hygiene measures and the use of fluoroquinolones, second- and third-generation cephalosporins, extended-spectrum penicillins, penicillins with beta-lactamase inhibitors, carbapenems, lincomycins and macrolides were collected for 2004 and 2005, and divided into pre-epidemic and epidemic periods. Using a multilevel Poisson regression analysis, CDAD incidence was linked to antibiotic use in the previous quarter and to certain hygiene measures. In the pre-epidemic period, the total use of the studied antibiotics was comparable between affected and unaffected hospitals. Higher use of second-generation cephalosporins, macrolides and all of the studied antibiotics were independently associated with a small increase in CDAD incidence [relative risk (95 % confidence interval): 1.14 per increase of 100 defined daily doses per 10 000 bed days (1.06–1.23), 1.10 (1.01–1.19) and 1.02 (1.01–1.03), respectively]. However the effect was too small to predict which hospitals might be more prone to 027-associated outbreaks.


1981 ◽  
Vol 51 (3) ◽  
pp. 750-754 ◽  
Author(s):  
V. J. Caiozzo ◽  
J. J. Perrine ◽  
V. R. Edgerton

Seventeen male and female subjects (ages 20–38 yr) were tested pre- and posttraining for maximal knee extension torque at seven specific velocities (0, 0.84, 1.68, 2.51, 3.35, 4.19, and 5.03 rad . s-1) with an isokinetic dynamometer. Maximal knee extension torques were recorded at a specific joint angle (0.52 rad below the horizontal plane) for all test speeds. Subjects were randomly assigned to one of three experimental groups: group A, control, n = 7; group B, training at 1.68 rad . s-1, n = 5; or group C, training at 4.19 rad . s-1, n = 5. Subjects trained the knee extensors by performing two sets of 10 single maximal voluntary efforts three times a week for 4 wk. Before training, each training group exhibited a leveling-off of muscular tension in the slow velocity-high force region of the in vivo force-velocity relationship. Training at 1.68 rad . s-1 resulted in significant (P less than 0.05) improvements at all velocities except for 5.03 rad . s-1 and markedly affected the leveling-off in the slow velocity-high force region. Training at 4.19 rad . s-1 did not affect the leveling-off phenomenon but brought about significant improvements (P less than 0.05) at velocities of 2.51, 3.35, and 4.19 rad . s-1. The changes seen in the leveling-off phenomenon suggest that training at 1.68 rad . s-1 might have brought about an enhancement of motoneuron activation.


1990 ◽  
Vol 259 (6) ◽  
pp. G1010-G1018 ◽  
Author(s):  
T. Kawasaki ◽  
F. J. Carmichael ◽  
V. Saldivia ◽  
L. Roldan ◽  
H. Orrego

The relationship between portal tributary blood flow (PBF) and hepatic arterial blood flow (HAF) was studied in awake, unrestrained rats with the radiolabeled microsphere technique. Six distinct patterns of response emerged. In group A (PBF+, HAF 0), ethanol, acetate, glucagon, prostacyclin, and a mixed diet increased PBF without a change in HAF; in group B (PBF+, HAF+), adenosine and histamine increased both PBF and HAF; in group C (PBF 0, HAF+), isoflurane and triiodothyronine did not change PBF but increased HAF; and in group D (PBF-, HAF+), halothane and vasopressin decreased PBF and increased HAF. Acute partial portal vein ligation decreased PBF (56%) and increased HAF (436%). Hypoxia (7.5% O2) decreased PBF (28%) and increased HAF (110%). In group E (PBF+, HAF-), acute hepatic artery ligation increased PBF (35%) and reduced HAF (74%), while in group F (PBF-, HAF-), thyroidectomy reduced PBF and HAF (36 and 47%, respectively). All blood flow responses were accompanied by the expected changes in both portal tributary and hepatic arterial vascular resistances. The data suggest that the portal and hepatic arterial vascular territories have regulatory mechanisms that allow for independent changes.


2018 ◽  
Vol 47 (1) ◽  
pp. 212-221 ◽  
Author(s):  
Cecilia Pascual-Garrido ◽  
Elizabeth A. Aisenbrey ◽  
Francisco Rodriguez-Fontan ◽  
Karin A. Payne ◽  
Stephanie J. Bryant ◽  
...  

Background: In this study, we investigate the in vitro and in vivo chondrogenic capacity of a novel photopolymerizable cartilage mimetic hydrogel, enhanced with extracellular matrix analogs, for cartilage regeneration. Purpose: To (1) determine whether mesenchymal stem cells (MSCs) embedded in a novel cartilage mimetic hydrogel support in vitro chondrogenesis, (2) demonstrate that the proposed hydrogel can be delivered in situ in a critical chondral defect in a rabbit model, and (3) determine whether the hydrogel with or without MSCs supports in vivo chondrogenesis in a critical chondral defect. Study Design: Controlled laboratory study. Methods: Rabbit bone marrow–derived MSCs were isolated, expanded, encapsulated in the hydrogel, and cultured in chondrogenic differentiation medium for 9 weeks. Compressive modulus was evaluated at day 1 and at weeks 3, 6, and 9. Chondrogenic differentiation was investigated via quantitative polymerase reaction, safranin-O staining, and immunofluorescence. In vivo, a 3 mm–wide × 2-mm-deep chondral defect was created bilaterally on the knee trochlea of 10 rabbits. Each animal had 1 defect randomly assigned to be treated with hydrogel with or without MSCs, and the contralateral knee was left untreated. Hence, each rabbit served as its own matched control. Three groups were established: group A, hydrogel (n = 5); group B, hydrogel with MSCs (n = 5); and group C, control (n = 10). Repair tissue was evaluated at 6 months after intervention. Results: In vitro, chondrogenesis and the degradable behavior of the hydrogel by MSCs were confirmed. In vivo, the hydrogel could be delivered intraoperatively in a sterile manner. Overall, the hydrogel group had the highest scores on the modified O’Driscoll scoring system (group A, 17.4 ± 4.7; group B, 13 ± 3; group C, 16.7 ± 2.9) ( P = .11) and showed higher safranin-O staining (group A, 49.4% ± 20%; group B, 25.8% ± 16.4%; group C, 36.9% ± 25.2%) ( P = .27), although significance was not detected for either parameter. Conclusion: This study provides the first evidence of the ability to photopolymerize this novel hydrogel in situ and assess its ability to provide chondrogenic cues for cartilage repair in a small animal model. In vitro chondrogenesis was evident when MSCs were encapsulated in the hydrogel. Clinical Relevance: Cartilage mimetic hydrogel may offer a tissue engineering approach for the treatment of osteochondral lesions.


Author(s):  
Carlos Edmundo Rodrigues FONTES ◽  
Ana Paula de ABREU ◽  
Aretuza Zaupa GASPARIM

ABSTRACT Background: Researches on Chagas disease still use several animals and rats, due to size and susceptibility were preferred by many authors. Aim: To develop an experimental model of megacolon in rats inoculated with the strain Y of Trypanosoma cruzi. Methods: Thirty male Wistar rats were distributed in three groups inoculated with different inoculants: Group A: 600000, Group B: 1000000 and Group C: 1500000 blood trypomastigotes of T. cruzi. Animals were sedated intramuscularly at zero inoculation time (T0) and 60 days after inoculation (T60), to perform the barium enema in order to evaluate the dilatation of the different segments of colon in a comparative study of the measurements obtained, using a digital caliper. Evidence of infection was performed by blood smear collected from the animal’s tail 18 days after inoculation with observation of blood forms. Results: Comparing the intestinal diameter of the inoculated animals with 60,0000 trypomastigotes in the T0 of infection with T60 days after the inoculation, significant dilatation was observed between the proximal, medial and distal segments (p<0.01), indicating the establishment of the megacolon model. In addition, comparing intestinal diameter between the different segments, with in the T0 of infection and the T60 after inoculation, significant alterations were observed (p<0.05). Conclusion: The proposed model was possible for in vivo studies of alterations due to infection by T. cruzi and functional alterations of the colon. In addition, the changes manifested in the colon are not directly proportional to the size of the inoculum, but to the time of infection that the animals were submitted, since the animals inoculated with 60,0000 blood forms were the ones which presented the most significant alterations.


2020 ◽  
Vol 57 (1) ◽  
pp. 299-305
Author(s):  
Ruxandra Margarit ◽  
Livia Alice Tanasescu ◽  
Dana Bodnar ◽  
Camelia Gabriela Ion ◽  
Mihai Burlibasa ◽  
...  

The aim of our study was to compare the fracture resistance of teeth presenting non-carious cervical lesions restored with different types of esthetic composite materials. 20 extracted unspoiled maxillary first molars were mechanically cleaned and immersed in saline solution containing 0.1% thymol at 4�C for a period of 48 hours. Cervical cavities with a cervical-occlusal diameter of 2 mm and a mesial-distal diameter of 3mm were filled with ormocer, flow nano-composite, nano-composite and compomer. Fracture resistance was tested with a universal loading machine (Lloyd Instruments), with a maximum force of 5 kN and a crosshead speed of 1.0 mm/min; the authors used NEXYGEN Data Analysis Software and ANOVA method. For the group A (commercial grade ormocer), the smallest load that determined the sample failure was 650 N and the highest load was 1050 N, the mean value being 858 N � 150.89 N. For the group B (commercial grade flow nano-composite), the smallest load is 530 N, the highest load is 800 N, mean value being 654 N � 112.6 N. For the group C (commercial grade nano-composite), the smallest load is 680 N, the highest load is 1200 N, mean value being 926 N � 209.35 N. For the group D (commercial grade compomer), the smallest load is 1100 N, highest load is 1250N, mean value being 1180 N � 62.04 N. A p value of 0.000311 (p[0.05) shows that there are significant differences between the four groups. Conclusions. The best fracture resistance of teeth presenting non-carious cervical lesions, restored with different types of esthetic composite materials is assured by the compomer, followed by the nano-composite, which proved to be superior to ormocer. The flow nano-composite gives the lowest fracture resistance.


2020 ◽  
Vol 37 (4) ◽  
pp. 259-269
Author(s):  
Beom Seok Kim ◽  
Ye Ji Lee ◽  
Hyo Bin Kim ◽  
Ki Jung Sung ◽  
Ju Hyun Jeon ◽  
...  

Background: This study aims to statistically analyze and compare the curative effect and satisfaction level between typical traditional Korean medicine treatment and nonsurgical spinal decompression treatment.Methods: Of the patients who were diagnosed with the cervical or lumbar herniated intervertebral disc at the Department of Acupuncture and Moxibustion Medicine at the Daejeon Korean Medicine Hospital from April 14<sup>th</sup> to August 25<sup>th</sup>, 2019, this study retrospectively analyzed the medical records of 31 patients who underwent nonsurgical spinal decompression treatment and traditional Korean medicine (assigned to Group A) and another 31 patients who received typical traditional Korean medicine alone (assigned to Group B). The clinical data were analyzed using IBM SPSS Version 23.0.Results: No statistically significant differences appeared in terms of sociodemographic, condition, and therapeutic characteristics, except whether the patient received Western medicine treatment, before or after a treatment with traditional Korean medicine. Group A exhibited higher variations in numeric rating scale, EuroQol- 5 dimension and EuroQol visual analogue scale scores compared to Group B as determined by independent sample <i>t</i> test and analysis of covariance. In addition, the satisfaction score of Group A was higher than that of Group B The result of cross analysis revealed that desire for continued treatment in Group A was higher than that of Group B.Conclusion: This retrospective observational study showed that the patients with nonsurgical spinal decompression treatment reported a greater reduction in pain, improved quality of life and satisfaction than patients receiving typical traditional Korean medicine.


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