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OBJECTIVE: The aim of this study was to evaluate the clinical efficacy of home-administered vital bleaching procedures and possible adverse effects derived from their use. One gel containing 3.5% hydrogen peroxide with a 5% potassium nitrate component (FKD, Kin Lab) was compared with a carbamide peroxide-based gel with a concentration of 10% (Opalescence, Ultradent). METHOD AND MATERIALS: Two sample groups were designed, each composed of 8 patients. All patients employed both bleaching products, 1 in the maxillary arch and the other in the mandibular arch on a random basis. The treatment was applied for 3 hours a day for 4 weeks. The degree of bleaching was evaluated using the Vita guide arranged by brightness. Dental sensitivity was measured with a specially designed 4-point scale. Gingival irritation was registered by the presence or absence of lesions in the marginal gingiva related to treatment. RESULTS: The degree of bleaching was similar with both products (4.8 Vita shade tabs). The hydrogen peroxide product with potassium nitrate provoked less dental sensitivity, although the difference between the 2 products was insignificant (P = .063). Gingival irritation appeared in 6 subjects, but was unrelated to the applied product. CONCLUSION: Under the conditions of this study, no statistically significant differences were detected between 3.5% hydrogen peroxide containing 5% potassium nitrate (FKD) and the 10% carbamide peroxide-based product (Opalescence). [ABSTRACT FROM AUTHOR]

Objective: The aim of this study was to evaluate the clinical efficacy of home-administered vital bleaching procedures and possible adverse effects derived from their use. One gel containing 3.5% hydrogen peroxide with a 5% potassium nitrate component (FKD, Kin Lab) was compared with a carbamide peroxide-based gel with a concentration of 10% (Opalescence, Ultradent). Method and Materials: Two sample groups were designed, each composed of 8 patients. All patients employed both bleaching products, 1 in the maxillary arch and the other in the mandibular arch on a random basis. The treatment was applied for 3 hours a day for 4 weeks. The degree of bleaching was evaluated using the Vita guide arranged by brightness. Dental sensitivity was measured with a specially designed 4-point scale. Gingival irritation was registered by the presence or absence of lesions in the marginal gingiva related to treatment. Results: The degree of bleaching was similar with both products (4.8 Vita shade tabs). The hydrogen peroxide product with potassium nitrate provoked less dental sensitivity, although the difference between the 2 products was insignificant (P = .063). Gingival irritation appeared in 6 subjects, but was unrelated to the applied product. Conclusion: Under the conditions of this study, no statistically significant differences were detected between 3.5% hydrogen peroxide containing 5% potassium nitrate (FKD) and the 10% carbamide peroxide-based product (Opalescence). [ABSTRACT FROM AUTHOR]

Kidney-specific with-no-lysine kinase 1 (KS-WNK1) is an isoform of WNK1 kinase that is predominantly found in the distal convoluted tubule of the kidney. The precise physiological function of KS-WNK1 remains unclear. Some studies have suggested that it could play a role in regulating potassium renal excretion by modulating the activity of the Na + -Cl - cotransporter (NCC). However, changes in the potassium diet from normal to high failed to reveal a role for KS-WNK1, but under a normal-potassium diet, the expression of KS-WNK1 is negligible. It is only detectable when mice are exposed to a low-potassium diet. In this study, we investigated the role of KS-WNK1 in regulating potassium excretion under extreme changes in potassium intake. After following a zero-potassium diet (0KD) for 10 days, KS-WNK1 -/- mice had lower plasma levels of K + and Cl - while exhibiting higher urinary excretion of Na + , Cl - , and K + compared with KS-WNK1 +/+ mice. After 10 days of 0KD or normal-potassium diet (NKD), all mice were challenged with a high-potassium diet (HKD). Plasma K + levels markedly increased after the HKD challenge only in mice previously fed with 0KD, regardless of genotype. KSWNK1 +/+ mice adapt better to HKD challenge than KS-WNK1 -/- mice after a potassium-retaining state. The difference in the phosphorylated NCC-to-NCC ratio between KS-WNK1 +/+ and KS-WNK1 -/- mice after 0KD and HKD indicates a role for KS-WNK1 in both NCC phosphorylation and dephosphorylation. These observations show that KS-WNK1 helps the distal convoluted tubule to respond to extreme changes in potassium intake, such as those occurring in wildlife. NEW & NOTEWORTHY The findings of this study demonstrate that kidney-specific with-no-lysine kinase 1 plays a role in regulating urinary electrolyte excretion during extreme changes in potassium intake, such as those occurring in wildlife.  .

Objectives: The purpose of this study was to assess if the use of intraoral positioning guides could increase the reproducibility of color measurements with a dental spectrophotometer., Methods: Twenty-three subjects were selected, and positioning guides for the maxillary arch of each participant were fabricated with clear 4 mm thermo-sheets. One orifice was made in the center of the clinical crown of the upper-right central incisor and another in the canine, with an external 6 mm diameter trephine. Color measurements were performed with a Vita EasyShade Compact IV dental spectrophotometer by the same operator in the same conditions. Forty measurements were taken per patient, 20 for each tooth, 10 with a positioning guide, and 10 without one. Before each measurement, the spectrophotometer was calibrated following the manufacturer's instructions., Results: Using the Wilcoxon test to evaluate nonparametric variables, there are statistically significant differences (P < .05) between the use or not of positioner for color recording with spectrophotometer. Greater repeatability of the measurements is obtained using repositioning split., Conclusions: Within the limitations of this study, the use of positioning guides provides greater reproducibility in spectrophotometer measurements for all parameters of tooth 11 and for some parameters of tooth 13., Clinical Significance: The use of a positioning guide for color measurement with a dental spectrophotometer allows a greater reproducibility of the measurements to be obtained. Achieving repeatable measurements is essential for studying the same area of the tooth, for example, in bleaching treatments and in color checks for prosthetic treatments., (© 2019 Wiley Periodicals, Inc.)

Objective: The aim of this study is to determine whether prolonging the daytime at-home bleaching treatment by 1 week increases the bleaching effect without causing more side effects., Materials and Methods: Fifty participants were randomly divided into two groups, (A) with a 14-day treatment and (B) with a 21-day treatment. A gel with 10% carbamide peroxide was applied for 2 h a day in custom trays. Color measurement was performed using a dental spectrophotometer on the right maxillary central incisor and the canine at baseline, at the end of treatment, and 1 and 6 months afterwards. Daily, participants recorded their tooth sensitivity and gingival irritation., Results: At the end of the treatment, the ΔE 00 of group B (5.77 ± 2.15) was significantly higher than the ΔE 00 of group A (4.74 ± 1.94) (p = 0.005 (95% CI: - 2.13 to - 0.39)). After 6 months, tooth color was more stable in group B. The ΔSGU values between the different appointment times were higher in the 3-week group. Participants from group B reported more side effects, but statistically, there were no differences compared with group A (p = 0.225 for tooth sensitivity and p = 0.758 for gingival irritation)., Conclusions: Daytime application of at-home bleaching for 3 weeks achieves greater bleaching results than for 2 weeks, immediately after treatment and 1 and 6 months afterwards. However, slightly more side effects could occur., Clinical Relevance: When daytime application of at-home bleaching is required, the treatment duration should be prolonged from 2 to 3 weeks to achieve greater and more stable results.

This study assessed 24 adult patients, suffering from severe chronic unilateral pain diagnosed as temporomandibular joint (TMJ) disorder (TMD). The full dentate patients had normal occlusion and had never received an occlusal therapy, i.e., were with natural dental evolution/maturation. The following functional and dynamic factors were assessed: (1) chewing function; (2) TMJ remodeling or the condylar path (CP); and (3) lateral jaw motion or lateral guidance (LG). CPs were assessed using conventional axiography, and LG was assessed by K7 jaw tracking. Seventeen (71%) of the 24 (100%) patients consistently showed a habitual chewing side. The mean (standard deviation [SD]) of the CP angles was 47.90 (9.24) degrees. The mean (SD) of the LG angles was 42.95 (11.78) degrees. Data collection emerged from the conception of a new TMD paradigm where the affected side could be the habitual chewing side, the side with flatter lateral jaw motion or the side with an increased CP angle. These data may lead to improved diagnosis, therapy plans and evolution in TMD patients.

Background: The authors conducted a retrospective study to evaluate the long-term (18-22 years) clinic results of titanium post and bonded amalgam core restorations with metal-ceramic crowns placed in patients., Methods: From 1992 through 1996, the authors placed 88 restorations in 66 patients. They measured the ferrule effect in the minor dentin collar area. In 2014, the authors analyzed the following variables: ferrule length, length and thickness of the post, and tooth position., Results: The overall survival of the restorations decreased over time with survival rates of 89.6% after 5 years of follow-up appointments and 64.2% after 18 years of follow-up appointments. There were 42 failures, and the maxillary premolars had the most failures. The teeth with 2 or more millimeters ferrule length had a higher survival rate than those with a 0 to less than 2 mm ferrule length; these results were not statistically significant., Conclusions: Statistically significant differences were detected according to the location of the tooth. The cores in the anterior teeth were 3.26 times more likely to fail than those in the molars, which presented higher survival rates; maxillary premolars had the most failures (28.5%). Both the metallic post length and its diameter did not influence restoration survival. The ferrule length was not statistically significant., Practical Implications: The clinical technique to restore endodontically treated teeth that includes a titanium post and bonded amalgam restorations results in greater coronal destruction but shows good long-term results, ease of fabrication, and modest cost in comparison with other techniques., (Copyright © 2017 American Dental Association. Published by Elsevier Inc. All rights reserved.)

Objective: The restoration of non-caries cervical lesions has long been a challenge. Until recently, compomers were the restorative materials of choice. The aim of this in-vivo study was to evaluate the long-term clinical performance of Dyract restorations in non-caries cervical lesions., Method and Materials: Forty-two patients with Dyract restorations of non-caries cervical lesions performed in 1995 by the same operator were included in this in-vivo retrospective study. After 20 years, restorations were evaluated by two calibrated examiners following the USPHS criteria modified by Ryge., Results: After 20 years, 38 of the 54 restorations included in this study remain in service (70.4%). Debonding was the cause of all failures. Marginal adaptation and marginal discoloration were the categories with poor values., Conclusion: Dyract restorations can be considered a treatment option for non-caries cervical lesions, because they show good long-term clinical performance for 20 years., Clinical Relevance: Dyract restorations continue to be an option to restore non-caries cervical lesions, due their good long-term clinical performance and the ease of the clinical procedure. The survival rate of these Dyract restorations was high after 20 years (70.4%). However, the limitations of marginal discoloration, marginal adaptation, and color match should be considered.

Purpose: The aim of this in vitro study was to evaluate the mechanical properties (bending strength and hardness) of seven different fiber reinforced composite posts, in relation to their microstructural characteristics., Materials and Methods: Two hundred eighty posts were divided into seven groups of 40, one group for each type of post analyzed. Within each group, 15 posts were subjected to three-point bending strength test, 15 to a microhardess meter for the Knoop hardness, and 10 to Scanning Electron Microscope in order to determine the diameter of the fibers and the percentage of fibers embedded in the matrix. To compare the flexural strength in relation to the type of fiber, matrix, and the hardness of the posts, a Kruskal-Wallis H test was used. The Jonckheere-Terpstra test was used to determine if the volume percent of fibers in the post influenced the bending strength., Results: The flexural strength and the hardness depended on the type of fibers that formed the post. The lower flexural strength of a post could be due to deficient bonding between the fiber and the resin matrix., Conclusion: According to the results, other factors, besides the microstructural characteristics, may also influence the mechanical properties of the post. The feature that has more influence on the mechanical properties of the posts is the type of fiber.

Objective: This randomized clinical trial evaluated the efficacy and safety of four gels of differing concentrations used for at-home vital bleaching., Materials and Methods: Ninety-six volunteers participated in the study and were divided into four groups of 24 individuals. A gel of differing concentration was used for each group: 10% and 15% carbamide peroxide and 7.5% and 9.5% hydrogen peroxide. The patients used the whitening agent in a tray without reservoirs for one hour per day for two weeks. The measurement of the change in tooth color was made by two observers in the maxillary right central incisor and with a colorimeter in both upper central incisors and canines, using the CIE L*a*b* and CIE L*C*h* values. Sensitivity was evaluated by the participants on a scale with values as follows: 0 = absent, 1 = minor, 2 = moderate, 3 = considerable, 4 = severe., Results: At the baseline, the observers noted darker colors than the colorimeter (p<0.01), and there were differences between incisors and canines in all the CIE L*a*b* and CIE L*C*h* values (p<0.001). In all of the groups and for all of the CIE L*a*b* and CIE L*C*h* parameters, there were color changes in the assessments made in the four maxillary teeth after treatment (p<0.001). There were no differences in ΔL* and ΔE* between the groups. The number of patients who experienced sensitivity and the intensity of the sensitivity were not significant., Conclusions: There were no differences in the degree of whitening among the different products. With all of the products there was an increase in L*, a decrease in chromatic intensity (C*), and an increase in the value (tone) or hue (h*).

This study investigated hydrogen peroxide (H2O2) concentration of two home bleaching gels, in their dispensing syringes and their degradation in vivo in intraoral bleaching trays. Two bleaching gels were studied, 7.5% hydrogen peroxide (HP) and 20% carbamide peroxide (CP). The concentration of H2O2 was determined in dispensing syringes. Twenty individuals were involved in this study. The gels were placed in trays of both arches and their degradation determined at 5, 10, 15, 20, 30, 40, 60 and 75 min. The concentrations of H2O2 in syringes were (HP) 8.12% and (CP) 7.95%. For the HP gel in custom-trays the concentration of H2O2 was 73% at 5 min and 42% after 75 min. In the 20% CP gel it was 75% at 5 min and 39% after 75 min. Activity decreased linearly up to 75 min, where the mean concentration of H2O2 exceeded 35% for the CP and HP gels.

Unlabelled: The literature about salivary lactate dehydrogenase (LDH) activity shows different results, conditioned by the diversity of methods used for sampling, handling and analysis., Objectives: The aim of this study was to design a protocol for quantifying salivary lactate dehydrogenase activity., Methods: Whole saliva samples were collected from 100 healthy volunteers by chewing a roll of cotton. Lactate dehydrogenase activity determinations were made with the Cobas Mira Plus II autoanalyser using the recommendations proposed by the International Federation of Clinical Chemistry (IFCC) and the French Society of Clinical Biology (SFBC). Samples were stored at room temperature (20-22 degrees C), in the refrigerator (4 degrees C) and freezer (-20 degrees C). The correction capacity of the autoanalyser was evaluated by making serial determinations in samples of saliva diluted in water., Results: The frozen samples, but not those stored in the refrigerator or at room temperature, showed an important degradation of lactate dehydrogenase activity. When the samples were diluted in water, the lactate dehydrogenase activity varied substantially with the International Federation of Clinical Chemistry method after correction, but not when using the French Society of Clinical Biology method., Conclusion: For salivary lactate dehydrogenase activity quantification we suggest that samples be stored at 4 degrees C and analyse with the French Society of Clinical Biology method.