Effect of tooth whitener on microhardness of tooth colour restorative materials
| Autor: | Funda Bayindir, K. M. Colak, İsmail Uzun |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Tooth whitening
Home bleaching Materials science genetic structures Tooth colour business.industry Mechanical Engineering Tooth surface Dentistry Condensed Matter Physics Peroxide Indentation hardness chemistry.chemical_compound chemistry Mechanics of Materials General Materials Science Sodium perborate Hydrogen peroxide business |
| Zdroj: | Materials Research Innovations. 13:28-31 |
| ISSN: | 1433-075X 1432-8917 |
| Popis: | The concept of whitening teeth is not new to new dentistry. Published reports of whitening methods date back to the 1800s, though it has periodically been a topic of interest since that time. Recently, tooth whitening has gained momentum after the first formal report of night guard vital bleaching to treat discoloured teeth was published in 1989. With the increased aesthetic demands of patients, vital bleaching has become a treatment option for discoloured teeth. In addition, agents with different concentrations have been introduced to obtain a whitening effect more quickly. The main reason for the tremendous popularity of bleaching procedures is their efficiency. It was reported that patients were glad they went through the procedure and 97% would recommend tooth bleaching to a friend. In the bleaching process, hydrogen peroxide (H2O2) quickly oxidises the stained macromolecules and breaks them into smaller fragments, which diffuse across the tooth surface, resulting in a whitening effect. For brightening discoloured teeth, the use of hydrogen peroxide or peroxide releasing agents, such as carbamide peroxide or sodium perborate, has become a popular treatment modality. A recently published review showed that tooth bleaching teeth is comparatively safe in terms of potential risk for alteration of dental hard tissue. Although bleaching is safe to soft tissues from a procedural standpoint, it may not be safe for dental materials with high erosive or degradation characteristics. Surface hardness is one of the most important physical characteristics of dental materials and it is defined as the resistance of a material to indentation or penetration. As hardness is related to materials strength, proportional limit and its ability to abrade or to be abraded by opposing dental structures/materials, any chemical softening resulting from bleaching has implications on the clinical durability of restorations. Although the use of bleaching agents is widespread, studies investigating the effect of bleaching treatments on the microhardness of restorative materials have reported conflicting results. The influence of various bleaching agents on physical properties, surface morphologies and colours of different restorative materials has been investigated in several in vitro studies simulating the clinical situation as closely as possible. In those studies, home bleaching products (10–16% carbamide peroxide) were generally used within a 2–4 week bleaching simulation with application intervals of 4–8 h/day. Tooth whiteners designed for in-office application (30–35% hydrogen or carbamide peroxide) were applied at treatment intervals of 15– 60 min (as recommended by the manufacturers). These different bleaching regimes were preferably used in the studies reviewed and are, therefore, not repeatedly mentioned when the results of the respective studies are described and discussed. However, it should be borne in mind that the total time period of application was much longer for the low concentrated regimes than for the highly concentrated ones. The purpose of the present paper is to determine the effect of bleaching agents on the microhardness of various tooth coloured restorative materials for an eight week application. |
| Databáze: | OpenAIRE |
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