Physicochemical Properties of Enamel After Microabrasion Technique

Abstract

AIM: This study aimed to evaluate the enamel microhardness, surface roughness, and chemical composition after microabrasion technique, followed by polishing and different immersion times in artificial saliva. MATERIALS AND METHODS: Ninety enamel blocks (25 mm2) from bovine incisors were divided into two groups (G1 and G2), and then subdivided in five subgroups (n = 9) according to their microabrasion treatment and polishing with a diamond paste: 35% phosphoric acid and pumice (H3PO4+Pum) and polishing; just H3PO4+Pum; 6.6% hydrochloric acid and silica (HCl+Sil) and polishing; just HCl+Sil; and control (no treatment). For G1, roughness and microhardness analyses were performed before (L1) and after (L2) microabrasion. After 15 (L3) and 30 (L4) days of immersion in artificial saliva, microhardness analysis was also performed. After (L4) analysis, the specimens were subjected to SEM analysis. G2 was used for the chemical analysis using energy dispersion testing (EDS). The data was subjected to statistical analysis (α = 5%). For roughness, L2 presented higher values than L1, except for the polished groups. For microhardness, L2 presented higher values than L1, except for unpolished groups. The L3 and L4 did not differ and were higher than L1. RESULTS: No changes were observed in the phosphorus concentrations of the microabrasioned enamel. However, the specimens treated with HCl+Sil were observed as having decreased calcium and increased chlorine and silica on the EDS test. CONCLUSION: Microabrasion followed by polishing and immersion in artificial saliva for 15 days is enough to increase the microhardness of microabrasioned enamel surfaces, although the microabrasion procedure can alter the mineral content of the enamel.

In situ assessment of the saliva effect on enamel morphology after microabrasion technique

“…Currently, the microabrasive agents used are 6.6% hydrochloric acid with silica, in a commercial presentation, or pumice added to 35% phosphoric acid, with mechanical application under low-speed rotation 5 . The application of the microabrasive system is commonly followed by enamel polishing with diamond paste [6][7] or fluoridated paste 2,4 .…”

“…The clinical success of this technique has been documented 1,2,5 . However, little is known about the effects of the microabrasive systems used on enamel surface, such as roughness and microhardness [6][7] and its behavior in the oral environment in contact with saliva. Since microabrasion provides both erosive and abrasive challenges by an acid, and abrasive and mechanical application, it is expected that the enamel surface will undergo mineral loss due to demineralization, in which saliva and its components have a role in maintaining the integrity of the tissue [8][9][10] .…”

Tooth enamel properties and morphology after microabrasion: an in situ study

“…Moreover, the mechanical application recommended for the microabrasion technique can emphasize these effects . Enamel microhardness and roughness can be influenced by a combination of the abovementioned factors, as described in previous studies . However, most of these studies have not considered the protective capacity of the oral environment, due to the presence of saliva and its components.…”

“…8,9 Enamel microhardness and roughness can be influenced by a combination of the abovementioned factors, as described in previous studies. [12][13][14][15][16][17][18] However, most of these studies have not considered the protective capacity of the oral environment, due to the presence of saliva and its components.…”

“…21 In addition to the fluoride present in saliva, fluoride from toothpaste can prevent demineralization by forming a layer of calcium fluoride on the enamel surface. 13 Most studies of enamel alterations due to microabrasion have an in vitro design, 14,[16][17][18] and have not considered the protective properties of the oral environment, mainly related to saliva. 12,14 Thus, an in situ model might simultaneously simulate intraoral events and standardize experimental conditions.…”