Biomaterial Database

The effect of bleaching agents on the surface hardness of tooth colored restorative materials. 2005

Nadia Malek Taher

Department of Restorative Dental Science, College of Dentistry, King Saud University, Riyadh, Saudi Arabia. nmataher@hotmail.com

OBJECTIVE The aim of this study was to evaluate the effect of at-home (Opalesence/Dr. kit 15%, Ultradent, Products, Inc. South Jordan, UT, USA) and in-office (Superoxol 35%, Sultan Chemists, Inc., Englewood, NJ, USA) bleaching on the surface hardness of the following tooth colored restorative materials: composite resin, Point-4 (P4), Kerr Corporation, Orange, CA, USA; ormocer, Admira (AD),VOCO, Germany; compomer Dyract AP (DY), Dentsply DeTrey GmbH, Germany; and resin modified glass ionomer cement, Fuji II LC (FL), GC Corporation, Japan. METHODS Sixty specimens were prepared; 15 specimens of each material (each group n = 5, control after 15 days, at-home and in-office). All specimens were stored in distilled water at room temperature for 24 hrs before testing. A universal testing machine (Micromet 2100 series micro hardness testers) was used for testing Vicker's surface hardness for the three groups for every tested material. All results were statistically analyzed with one way analysis of variance (ANOVA), Post hoc Tukey HSD tests (P < 0.05), and percentage changes for Tukey. RESULTS All the tested materials showed an increase in Vicker's surface hardness between base line (24 hrs) and the control group after 15 days storage in distilled water except DY which showed a decrease in surface hardness. All tested materials showed a decrease in surface hardness from control group after 15 days and both at-home and in-office bleaching agents except DY which showed increased values. CONCLUSIONS At-home as well as in-office bleaching agents have a softening effect on some tooth colored restorative material, and the patient must be aware before using them.

UI	MeSH Term	Description	Entries
D008422	Materials Testing	The testing of materials and devices, especially those used for PROSTHESES AND IMPLANTS; SUTURES; TISSUE ADHESIVES; etc., for hardness, strength, durability, safety, efficacy, and biocompatibility.	Biocompatibility Testing,Biocompatible Materials Testing,Hemocompatibility Testing,Testing, Biocompatible Materials,Testing, Hemocompatible Materials,Hemocompatibility Testings,Hemocompatible Materials Testing,Materials Testing, Biocompatible,Materials Testing, Hemocompatible,Testing, Biocompatibility,Testing, Hemocompatibility,Testing, Materials,Testings, Biocompatibility
D010545	Peroxides	A group of compounds that contain a bivalent O-O group, i.e., the oxygen atoms are univalent. They can either be inorganic or organic in nature. Such compounds release atomic (nascent) oxygen readily. Thus they are strong oxidizing agents and fire hazards when in contact with combustible materials, especially under high-temperature conditions. The chief industrial uses of peroxides are as oxidizing agents, bleaching agents, and initiators of polymerization. (From Hawley's Condensed Chemical Dictionary, 11th ed)	Peroxide
D012117	Resins, Synthetic	Polymers of high molecular weight which at some stage are capable of being molded and then harden to form useful components.	Dental Resins,Dental Resin,Resin, Dental,Resin, Synthetic,Resins, Dental,Synthetic Resin,Synthetic Resins
D002516	Ceramics	Products made by baking or firing nonmetallic minerals (clay and similar materials). In making dental restorations or parts of restorations the material is fused porcelain. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed & Boucher's Clinical Dental Terminology, 4th ed)	Ceramic
D003188	Composite Resins	Synthetic resins, containing an inert filler, that are widely used in dentistry.	Composite Resin,Resin, Composite,Resins, Composite
D003793	Dental Restoration, Permanent	A restoration designed to remain in service for not less than 20 to 30 years, usually made of gold casting, cohesive gold, or amalgam. (Jablonski, Dictionary of Dentistry, 1992)	Dental Fillings, Permanent,Dental Filling, Permanent,Dental Permanent Filling,Dental Permanent Fillings,Dental Restorations, Permanent,Filling, Dental Permanent,Filling, Permanent Dental,Fillings, Dental Permanent,Fillings, Permanent Dental,Permanent Dental Filling,Permanent Dental Fillings,Permanent Dental Restoration,Permanent Dental Restorations,Permanent Filling, Dental,Permanent Fillings, Dental,Restoration, Permanent Dental,Restorations, Permanent Dental
D003799	Dental Stress Analysis	The description and measurement of the various factors that produce physical stress upon dental restorations, prostheses, or appliances, materials associated with them, or the natural oral structures.	Analyses, Dental Stress,Analysis, Dental Stress,Stress Analyses, Dental,Stress Analysis, Dental,Dental Stress Analyses
D004338	Drug Combinations	Single preparations containing two or more active agents, for the purpose of their concurrent administration as a fixed dose mixture.	Drug Combination,Combination, Drug,Combinations, Drug
D005899	Glass Ionomer Cements	A polymer obtained by reacting polyacrylic acid with a special anion-leachable glass (alumino-silicate). The resulting cement is more durable and tougher than others in that the materials comprising the polymer backbone do not leach out.	Glass Ionomer Cement,Glass Polyalkenoate Cement,Polyalkenoate Cement,Polyalkenoate Cements,Glass Polyalkenoate Cements,Glass-Ionomer Cement,Cement, Glass Ionomer,Cement, Glass Polyalkenoate,Cement, Glass-Ionomer,Cement, Polyalkenoate,Cements, Glass Ionomer,Cements, Glass Polyalkenoate,Cements, Glass-Ionomer,Cements, Polyalkenoate,Glass-Ionomer Cements,Ionomer Cement, Glass,Polyalkenoate Cement, Glass
D006244	Hardness	The mechanical property of material that determines its resistance to force. HARDNESS TESTS measure this property.	Hardnesses