The Effects of Etching, Micro-abrasion, and Bleaching on Surface Enamel

Abstract

Conservative techniques for improving the appearance of discolored teeth have become popular in the past decade. These include: in-office bleaching with 30% hydrogen peroxide, which is applied on etched enamel with a gauze pad and then exposed to a bleaching light; home bleaching with a mild form of peroxide, such as 10% carbamide peroxide, which is applied on the tooth surface with custom-made mouthguards; and enamel micro-abrasion with 18% hydrochloric acid, which is applied in a pumice slurry. In this study, the in-office bleaching and enamel micro-abrasion techniques were performed on extracted teeth for investigation of their microscopic effects on the surface enamel. Specimens treated only with 37% phosphoric acid showed an enamel loss of 5.7 +/- 1.8 microns. The specimens treated with 37% phosphoric acid followed by 30% hydrogen peroxide showed enamel loss of 5.3 +/- 1.6 microns; this loss was probably not caused by the hydrogen peroxide, but rather by the etching with 37% phosphoric acid which preceded the hydrogen peroxide application. A direct application of 18% hydrochloric acid for 100 s resulted in a loss of 100 +/- 47 microns. The extent of enamel loss was much greater when the 18% hydrochloric acid was applied in a pumice slurry for the same period of time (360 +/- 130 microns), and the effect was time-dependent. Thus, the pumice and rotary prophy cup used in conjunction with the 18% hydrochloric acid contributed markedly to the loss of surface enamel, enhancing the non-selective stain-removing action of the hydrochloric acid. Therefore, the hydrochloric acid-pumice technique must be used clinically with caution.

Surface effects after a combination of dental bleaching and enamel microabrasion: An <i>in vitro</i> and <i>in situ</i> study

“…This is because the stain removal depends on the erosive action of the acid present in the microabrasive product 2,3,5,15) , justifying the reduction in mineralization of the enamel surface after microabrasion. Those current observations are in agreement with other studies 13,16) . When combined with dental bleaching, the reduction in microhardness of the enamel was not significantly different when compared with values observed after microabrasion only (GII HS/GIIAS) for all conditions.…”

Management of white spots: resin infiltration technique and microabrasion

“…However, substantial amounts of enamel often unfortunately have to be eroded to improve appearance with this technique. 13 Resin infiltration technique is an alternative therapeutic approach to prevent further progression of enamel lesions. This treatment aims to occlude the microporosities within the lesion body by infiltration with low-viscosity light-curing resins that have been optimized for rapid penetration into the porous enamel.…”

Clinical Effectiveness of Two Microabrasion Materials for the Removal of Enamel Fluorosis Stains

“…The amount and ease of white stain removal depends on the type of acid and abrasive employed, as well as the application time and pressure. 19,[24][25][26] Studies that evaluated the amount of enamel loss after the application of PREMA and Opalustre found that these compounds led to a lower removal of enamel when compared to the use of an 18% HCl/pumice mixture. 19,[24][25][26] Numerous studies have been conducted in order to evaluate the amount of enamel loss after microabrasion techniques.…”

“…19,[24][25][26] Studies that evaluated the amount of enamel loss after the application of PREMA and Opalustre found that these compounds led to a lower removal of enamel when compared to the use of an 18% HCl/pumice mixture. 19,[24][25][26] Numerous studies have been conducted in order to evaluate the amount of enamel loss after microabrasion techniques. The use of 18% HCl and pumice mixture for 10 five-second successive applications resulted in an initial removal of 12 µm of enamel and 50 five-second applications removing approximately 36-100 µm of enamel.…”