Profilometric and Microradiographic Studies on the Effects of Toothpaste and Acidic Gel Abrasivity on Sound and Demineralized Bovine Dental Enamel

Abstract

The objective of this study was to assess the abrasive effects of toothpastes and acidic F gels on sound and demineralized enamel. Pairs of enamel specimens were cut from bovine incisors, embedded in epoxy resin and polished. An artificial subsurface lesion of 80–90 µm depth was created in one specimen from each pair. The samples were covered with adhesive tape, thereby exposing the enamel for abrasivity testing. All samples were divided into six groups of 15 and brushed with a slurry (1:3) of F gel or toothpaste and human saliva. Brushing with water (control) or with slurry was carried out (16,000 strokes) using a medium toothbrush (load 275 g) mounted in a brushing machine. Abrasion was evaluated using laser profilometry, and was about 50% less on sound than on demineralized enamel (p < 0.001). In the latter, brushing with water (0.09 ± 0.03 µm) or with fluoride-free gel (0.08 ± 0.03 µm) resulted in negligible wear. With a medium-abrasive paste (1.76 ± 0.85 µm) and an acidic F gel (2.48 ± 0.72 µm), brushing abrasion was significantly greater (p < 0.001) than with a low-abrasive paste (0.84 ± 0.38 µm). The greatest wear (16.6 ± 10.8 µm) was observed with high-abrasive paste (p < 0.001), and here transversal microradiography revealed a complete loss of the pseudointact surface after brushing. In vitro formed caries-like lesions can be abraded (by toothbrushing) more easily than sound enamel; hence, initial white spot lesions should preferably be brushed with oral hygiene products of low abrasivity.

Physical-chemical characteristics of whitening toothpaste and evaluation of its effects on enamel roughness

“…This finding suggests that the pH may be an important factor when considering the impact of the toothpaste on the enamel surface. 13,15 G2 (Close-UP Whitening  ) presented a pH closest to 7 and altered the enamel surface when brushing was preceded by application of the bleaching agent.…”

“…The concomitant use of abrasive toothpastes during at-home bleaching procedures reportedly increases the roughness of dental enamel. 11,[15][16][17][18] The purpose of this study was to evaluate the physical-chemical characteristics of the whitening toothpastes by determining their effect on bovine enamel surfaces during brushing after treatment by a bleaching agent. The classical alternative hypothesis that was investigated was: the composition of the tested toothpastes does not interfere with enamel surface roughness after the bleaching treatment.…”

Susceptibility of Acid-Softened Enamel to Mechanical Wear – Ultrasonication versus Toothbrushing Abrasion

“…In this group, abrasion reached a plateau after 250 strokes and no further increase could be observed by application of 100 additional strokes. As shown by Kielbassa et al [2005], brushing with distilled water is nearly unable to remove sound enamel, while brushing with toothpaste slurry may remove sound enamel but to a lesser extent than demineralized enamel. Therefore, differences in enamel loss by toothbrushing with distilled water or toothpaste slurry might be related to the abrasivity of the toothpaste.…”

Evaluation of surface roughness of a nanofill resin composite after simulated brushing and immersion in mouthrinses, alcohol and water

“…However, studies have shown that the movement of agents associated with the toothbrushing abrasive in a dentifrice and the toothbrush bristles, can cause damage to the brushed substrate, capable of altering the restorative material roughness [11][12][13][14][15][16] . The abrasives in dentifrices have been related to dental wear (abrasion) and over time, can also cause an increase in the surface roughness of restorative materials, leading to greater plaque retention and composite pigmentation 12,13,15 . Mouthrinses have also been used for centuries for the purpose of providing oral health and cosmetic benefits 17 and in the last few years their use has attracted the curiosity of the researchers because of their ability to modify the surface of composite resins.…”