(1/38) Comparison of in vitro fluoride uptake from whitening toothpastes and a conventional toothpaste in demineralised enamel.
Studies on the compatibility of abrasives and fluoride compounds deal exclusively with fluoride uptake and remineralization after storing the enamel specimens in a toothpaste-saliva mixture. The influence of brushing on the fluoride uptake when highly abrasive toothpastes are used has hardly been investigated so far. The aim of the present study was to investigate fluoride uptake in initially demineralised dental enamel after storage in, or brushing with, whitening toothpaste slurries, compared to a conventional toothpaste. For this purpose two widely available whitening toothpastes with ionically bound fluoride (sodium fluoride NaF), two with covalently-bound fluoride toothpastes (sodium monofluorophosphate, NaMFP) and a conventional amine fluoride toothpaste (AmF) were compared. The fluoride uptake after use of the AmF toothpaste was shown to be statistically significantly higher than that after application of the NaF toothpastes, which in turn was statistically significantly higher than the uptake resulting from NaMFP application. The fluoride uptake was slightly higher when the enamel samples were brushed with NaF toothpaste, rather than just stored in the respective toothpaste slurry. Brushing with highly abrasive toothpastes did not negatively influence fluoride uptake in demineralised dental enamel. The ionic form of the fluoride in toothpastes appears to be critical for increased fluoride uptake. The acidic components of the AmF toothpaste improved fluoride uptake compared to alkaline NaF toothpastes. (+info)
(2/38) Bleaching of nonvital teeth. A clinically relevant literature review.
Today, the bleaching of nonvital, discolored teeth is a low-risk routine treatment for improving esthetics. This review article focuses on the etiology of tooth discolorations, different treatment techniques, and risks of bleaching procedures. Some tooth discolorations in endodontically treated teeth are caused by dental treatments. The three most popular techniques for nonvital tooth bleaching are the walking bleach technique, inside/outside bleaching, and in-office bleaching. The walking bleach technique is a relatively reliable, fairly simple technique for dentists and patients. Inside/outside bleaching can be used additionally when internal and external bleaching must be combined. In-office bleaching seems to be a short-term solution, the effects of which can largely be attributed to dehydration of the teeth. There are still some open questions concerning the bleaching agents. Improved safety seems desirable with regard to adding thiourea as a scavenger of radicals or newer materials such as sodium percarbonate. The thermocatalytic technique, insufficient cervical sealing, and high concentrations of bleaching agents should be avoided, as this can increase the risk of cervical root resorptions. Patients should be informed about the low predictability of bleaching success and the risk of recurrent discoloration. The risk of cervical root resorption should be discussed with the patient. There is a strong correlation between root resorption and dental trauma. (+info)
(3/38) Tensile bond strength of a lithium-disilicate pressed glass ceramic to dentin of different surface treatments.
The effects of desensitizer, disinfectant, saliva, blood, and hydrogen peroxide on the tensile bond strength between adhesive and ceramic as well as between adhesive and dentin were examined. Sixty 7x3 mm pressed ceramic discs of IPS e.max were fabricated and randomly assigned to six groups of different dentin surface treatments (control, desensitizer, disinfectant, saliva, blood, and hydrogen peroxide). Representative samples of fractured specimens were observed by SEM (scanning electron microscopy). There were significant differences between the control group and saliva, blood, and hydrogen peroxide groups (p<0.05). However, there were no significant differences between any other dentin surface treatment groups (p>0.05). Results of this study suggested that only saliva, blood, and hydrogen peroxide influenced the tensile bond strength between dentin and ceramic. (+info)
(4/38) Diffusion of peroxides through dentine in vitro with and without prior use of a desensitizing varnish.
(5/38) The effect of enamel bleaching on the shear bond strengths of metal and ceramic brackets.
(6/38) A novel method for testing the veridicality of dental colour assessments.
(7/38) Bleaching using 30% hydrogen peroxide and sodium hydrogen carbonate.
This study investigated the bleaching efficacy of a mixture of sodium hydrogen carbonate (NaHCO(3)) and 30% hydrogen peroxide (H(2)O(2)), the latter being an active ingredient in in-office bleaching products. A commercially available 35% H(2)O(2)-based in-office bleaching product was used as a control and for comparison. Enamel surfaces after bleaching were evaluated for post-bleaching color change, Vickers hardness, surface roughness, erosion depth, and surface morphology (SEM images). The bleaching efficacy of 30%H(2)O(2)-NaHCO(3) was comparable to that of control, and favorable results over the control were obtained after bleaching with 30%H(2)O(2)-NaHCO(3), lower increase in surface roughness, smaller erosion depth, and reduced extent of enamel erosion based on SEM images. These results were obtained because an addition of NaHCO(3) to H(2)O(2) changed the initially low pH to a higher one. (+info)
(8/38) Ex-vivo evaluation of the intrapulpal temperature variation and fracture strength in teeth subjected to different external bleaching protocols.