Tooth-Bleaching: A Review of the Efficacy and Adverse Effects of Various Tooth Whitening Products.

Tooth bleaching (whitening) is one of the most common and inexpensive method for treating discolouration of teeth. Dental aesthetics, especially tooth colour, is of great importance to majority of the people; and discolouration of even a single tooth can negatively influence the quality of life. Therefore, a review of the literature was carried out (limited to aesthetic tooth-bleaching) to provide a broad overview of the efficacy and adverse effects of various tooth whitening products on soft and hard oral tissues.

In vitro evaluation of variances between real and declared concentration of hydrogen peroxide in various tooth-whitening products.

Objectives: The aim of this in vitro study was to analyze the real hydrogen peroxide (HP) concentration in various commercially available tooth-whitening products containing HP and/or carbamide peroxide (CP).

Materials And Methods: Sixteen commercially available tooth-whitening products containing various concentrations of CP or HP were investigated. The products were divided into four groups: dentist-supervised home bleaching products (Group 1, n = 5), in-office bleaching products (Group 2, n = 4), over-the-counter bleaching products (Group 3, n = 3) and whitening toothpastes and rinses (Group 4, n = 4).

IPNs from Cyclodextrin:Chitosan Antioxidants: Bonding, Bio-Adhesion, Antioxidant Capacity and Drug Release.

IPNs are unique "alloys" of cross-linked polymers in which at least one network is synthesized and/or cross-linked in the presence of the other. IPNs are also known as entanglements of polymer networks that are ideally held together only by permanent topological interactions. The objectives of this study are to evaluate novel chitosan-based functional drug delivery systems that can be successfully incorporated into "dual action bioactive tooth restorative materials".

Insights into and relative effect of chitosan-H, chitosan-H-propolis, chitosan-H-propolis-nystatin and chitosan-H-nystatin on dentine bond strength.

Objective: The purpose of the study was to design and evaluate novel functional chitosan hydrogels (chitosan-H-propolis, chitosan-H-propolis-nystatin and chitosan-H-nystatin) by using the chitosan-H polymer as "dual function restorative materials".

Materials And Methods: The nystatin/antioxidant carrier gel was prepared by dispersion of the corresponding component in glycerol and 3% acetic acid with 5% chitosan gelling agent was then added to the dispersion with continuous mixing. The natural bio-adhesive functionalized chitosan hydrogels were combined with built in drug delivery system and bio-actives such as propolis in order to increase the dentin bond strength capacity and maintain therapeutic properties of the alternative drug delivery system.

A clinical study of the effectiveness of a light emitting diode system on tooth bleaching.

Unlabelled: The purpose of this study was to evaluate the efficacy of a Light Emitting Diode (LED) System (BriteWhite) on tooth bleaching.

Method: eeth 11 and 21 of twenty one subjects were treated in the chair with a LED light and 44% carbamide peroxide gel, followed by an at-home treatment period of 14 days with 35% carbamide peroxide. The color of the teeth was measured with a spectrophotometer (L*; a*; b*) before treatment (control) and after the above mentioned two stages.

The pH Levels of Different Methamphetamine Drug Samples on the Street Market in Cape Town.

The purpose of this study was to determine the pH levels of 29 different samples of methamphetamine on the street market in Cape Town. The sample was dissolved in water and the pH of each sample determined. The pH levels varied from 3.

In vivo Spectrophotometric Assessment of the Tooth Whitening Effectiveness of Nite White 10% with Amorphous Calcium Phosphate, Potassium Nitrate and Fluoride, Over a 6-month Period.

Unlabelled: To clinically evaluate the effectiveness of Nite White 10% carbamide peroxide with amorphous calcium phosphate, potassium nitrate and fluoride over a 6-month follow-up period. Nite White was applied nightly for 14 days, according to the manufacturer's instructions. The color of teeth 11 and 21 of twenty one subjects was measured with a spectrophotometer (L(*); a(*); b(*)).

Orthodontic molar brackets: the effect of three different base designs on shear bond strength.

The purpose of the study was to assess the relative base designs of three different maxillary molar stainless steel brackets with reference to the shear bond strength of three different adhesive resins. The molar brackets used were Victory series (3M Unitek), Upper Molar (GAC) and Optimesh XRT (Ormco). The adhesives used were Transbond XT (3M Unitek), Enlight (Ormco) and Sure Ortho Light Bond (Sure Orthodontics).

Cytotoxicity of recent dentin bonding agents on mouse fibroblast cells.

Objectives: To compare the cytotoxicity of the polymerized bonding agents Scotchbond 1 (3M ESPE), Prime and Bond NT (Dentsply DeTrey), Xeno III (Dentsply DeTrey), and Clearfil Protect Bond (primer and bond parts; Kuraray) on mouse fibroblast cells. Xeno III was also tested through thin dentin disks.

Method And Materials: Near-confluent 3T3 cells were exposed to Dulbecco modified eagle's medium extractions from the above-mentioned agents, and the cell viability (survival rate) was measured using the standard MTT assay and related to the nonexposed controls.

Antimicrobial activity of two South African honeys produced from indigenous Leucospermum cordifolium and Erica species on selected micro-organisms.

Background: Honey has been shown to have wound healing properties which can be ascribed to its antimicrobial activity. The antimicrobial activity can be effective against a broad spectrum of bacterial species especially those of medical importance. It has also been shown that there is considerable variation in the antimicrobial potency of different types of honey, which is impossible to predict.

Microleakage and confocal laser studies of 2 single-step self-etching bonding agents/systems.

Objectives: This study investigated the microleakage, etching ability, and dentin-restorative interface of 2 different single-step self-etching bonding agents with compomers as restoratives.

Method And Materials: Fifteen extracted noncarious human premolars were used for each dental material system. The bonding agent Xeno III was used with their compomer Dyract AP (Dentsply) and Adper Prompt L-Pop with their compomer Z2000 (3M Espe).

Effect of power density on shrinkage of dental resin materials.

This study compares volumetric changes and rates of shrinkage during different stages of polymerization of dental resin composites and compomers exposed to the same total energy by using two different combinations of power density and exposure duration. A hybrid composite and its equivalent flowable and a compomer and its equivalent flowable were exposed using a halogen curing unit set at 400 mW/cm2 for 40 seconds and 800 mW/cm2 for 20 seconds: delivering 16 J/cm2 in both cases. Volumetric changes were recorded every 0.

The effects of light intensity and method of exposure on the hardness of four light-cured dental restorative materials.

Aim: To determine the microhardness of several light-curing dental restorative materials at the top surface as well as at a depth of 2mm.

Methods: Comparisons were made using different light sources. Four groups of five specimens each (3mm diameter, 2mm thick) of Z250 (composite), Filtek Flow (flowable composite), Dyract AP (compomer) and Dyract Flow (flowable compomer) were cured using different methods of exposure.

The effect of different power densities and method of exposure on the marginal adaptation of four light-cured dental restorative materials.

Purpose: To determine whether marginal adhesion is sensitive to different irradiation parameters, we investigated the in vitro adhesion values of four dental resins on metal surfaces.

Methods: Four groups of eight specimens each of Z250, Filtek flow, Dyract AP and Dyract flow were placed in pre-treated stainless steel cavities and irradiated using different methods of exposure. The curing lights used were a Spectrum 800 halogen curing light at settings of 800 and 450 mW/cm(2) and an Optilux 501 ramping light.

The effect of an additional flowable compomer layer on microleakage of Class V compomer restorations.

Background: Polymerisation shrinkage and the associated stress on composite resins and surrounding structures have been regarded as a major cause of leakage and clinical failures in modern polymer restorations. The purpose of this study was to investigate the effect of an additional flowable compomer layer on the microleakage of Class V dental cavities, which were further filled with a compomer.

Method: Cavities (32) were prepared in human premolars, conditioned with a non-rinsing agent (Prime & Bond NRC) and treated with the bonding agent (Prime & Bond NT).

Compomers: adhesion and setting reactions.

The term compomer is misleading as it suggests a combination of glass-ionomer and composite technology. This has led to confusion as to its clinical uses as well as the way it bonds to tooth structure. However, the properties and adhesion of compomers to tooth structure suggest a closer link to composites than to glass-ionomers.

A 3-year clinical evaluation of a compomer, a composite and a compomer/composite (sandwich) in class II restorations.

Purpose: To compare the clinical performance of Dyract, Spectrum-TPH and Dyract layered with Spectrum-TPH (sandwich) in Class II restorations of permanent dentitions.

Materials And Methods: 23 adult patients aged 25-62 were selected at random in a general dental practice. Each patient had 3 bicuspid teeth restored with Dyract, Spectrum-TPH and a "sandwiched" combination where Dyract was covered by the composite resin TPH.