A randomised clinical trial to determine the abrasive effect of the tongue on human enamel loss with and without a prior erosive challenge

Abstract

. A randomised clinical trial to determine the abrasive effect of the tongue on human enamel loss with and without a prior erosive challenge. Journal of Dentistry, 58, 48-53. DOI: 10.1016/j.jdent.2017 University of Bristol -Explore Bristol Research General rightsThis document is made available in accordance with publisher policies. Please cite only the published version using the reference above. Full terms of use are available: http://www.bristol.ac.uk/pure/about/ebr-terms 1 A Randomised clinical trial to determine the abrasive effect of the tongue on human enamel loss with and without a prior erosive challenge ABSTRACT Objectives: To investigate the abrasive effect of the tongue on human enamel loss with and without a prior dietary acid challenge in an in situ model. Methods:A single centre, single blind, randomly allocated, split mouth, four treatment regimen, in situ study in healthy adult volunteers was undertaken. Twenty four subjects wore two lower intra-oral appliances each fitted with 4 human enamel samples 6 hours/day for 15 days. The samples were treated with either 50ml orange juice or water for 5 minutes ex vivo 4x /day; prior to being licked or not licked with the subject's tongue for 60 seconds. There were 2 samples per group per subject. Surface loss was measured by contact profilometry. Results:23 subjects completed the study with no adverse events. The mean loss of enamel at 15 days was: 0.08 μm for water without licking, 0.10 μm with water and licking; 1.55 μm with orange juice alone, 3.65 μm with orange juice and licking. In the absence of erosive challenge, licking had no detectable effect on enamel loss p=0.28. Without licking, orange juice had a highly significant effect on loss compared to water, p<0.001. Erosive challenge followed by licking more than doubled the loss of enamel p<0.001. Conclusions:When enamel was exposed to orange juice prior to licking, tissue loss as a result of tongue abrasion of the eroded surface was increased, and double that of the erosive challenge alone. Licking enamel with the tongue had no perceptible effect on enamel loss in the absence of the erosive challenge. Clinical Significance:Enamel wear resulting from tongue abrasion on tooth surfaces softened by acid challenge, can be an unavoidable consequence of oral function. This may account for the pattern of erosive toothwear on palatal and occlusal tooth surfaces, reinforcing the importance of restricting the frequency of dietary acid challenge in susceptible individuals.

Influence of mandibular and palatal intraoral appliances on erosion in situ study outcome

“…This procedure was included in the experimental design since it is generally present in intraoral appliances of previous in situ studies 11 , 27 to avoid the incidence of mechanical forces. A previous study showed that tongue abrasion enhances loss of eroded enamel 28 . However, in the present study, the higher enamel loss seen in the blocks of the maxillary appliances might not be a consequence of tongue abrasiveness, since the wire inhibited the contact between enamel and tongue.…”

Impact of a simplified in situ protocol on enamel loss after erosive challenge

“…The softened erosive layer consists of a group of crystals separated by large spaces [ 40 ], which are vulnerable to abrasive or frictional forces [ 27 ] causing further enamel loss. Seong et al (2017) demonstrated that enamel loss resulting from tongue abrasion on eroded surfaces could be an unavoidable consequence of oral function [ 9 ]. Therefore, the higher enamel loss found in the blocks located in the maxillary appliance could be a partial result of tongue abrasion over the eroded surfaces, despite the metal wires placed over the enamel blocks to avoid the abrasive effect of soft tissues and tongue.…”

“…In addition, variables can be tested individually and new variables can be introduced gradually. Different in situ erosion experimental models have been reported [ 6 , 8 , 9 ]. Adequate models should simulate the clinical situation as close as possible, especially concerning the effect of human saliva, which is known to be a relevant factor in the development and progression of erosive lesions [ 10 , 11 , 12 ].…”

What can a dentist learn from an astrophysicist? A photographic evaluation of the long‐term impact of amyotrophic lateral sclerosis on the orofacial sphere, using the example of Stephen Hawking: A historical case report

“…Moving on to his early fifties (Figure 3), the maxillary anterior teeth show an inverted incisal edge curvature due probably to progressive loss of substance, as well as to the effects of the protruding tongue witnessed in these photographs. Tongue protrusion to clear the upper airway combined with a buccal acidic environment, are likely to be at the origin of this phenomenon 22 …”

“…Tongue protrusion to clear the upper airway combined with a buccal acidic environment, are likely to be at the origin of this phenomenon. 22 The disturbance of the muscular balance of the orofacial sphere accompanied by the loss of several teeth can be responsible for dental displacement. Around the age of 30, mandibular anterior crowding seems to have occurred, with the proclination of one of the lower incisors.…”