An investigation of the relationship between erosive tooth wear and gastro-oesophageal reflux

Abstract

This thesis investigated predictive factors for erosive tooth wear in patients with Gastro-oesophageal Reflux disease symptoms. The studies included an in-vitro laboratory study, a case-control study and an in-vivo clinical study. The erosive effect of dietary and intrinsic acids on enamel samples and the protective effect of acquired enamel pellicle against an acidic challenge were investigated in-vitro. Human enamel samples (n=240) were exposed to citric acid (CA) (pH 3.2), hydrochloric acid (HCl) (pH 2.2) and artificial gastric juice (AGJ) (pH 1.1) with and without the presence of acquired enamel pellicle. The mean microhardness change increased with an increase in erosion time resulting in a softer enamel surface, from 30s to 300s for CA from 46.2 (2.8) KHN to 95.3 (2.8) KHN, CA with AEP from 55.1 (2.9) KHN to 116.0 (5.5) KHN, HCl from 52.5 (4.6) KHN to 109.5 (4.4) KHN, HCl with AEP from 66.02 (2.3) KHN to 123.7 (3.4) KHN. AGJ from 120s to 300s: 204.7 (37.5) KHN to 152 (22.1) KHN, AGJ with AEP from 206.5 (43.1) KHN to 245.4 (39.8) KHN. The mean step height increased with the increase in erosion time From 30s to 300 for CA 0.16 (0.11) um to 2.21 (0.94) um, CA with AEP 0.08 (0.04) um to 1.44 (0.46) um, HCl 0.54 (0.21) um to 4.58 (0.83) um, HCl with AEP 1.88 (0.98) um to 6.7 (0.58) um. AGJ from 120s to 300s: 16.6 (3.4) um to 27 (8.3) um and AGJ with AEP from 19.3 (4.5) to 36.3 (7.1) um. However, the presence of acquired enamel pellicle protected against dietary acids (citric acid) but not against intrinsic acids (HCl and artificial gastric juice). A case-control study assessed the association of gastro-oesophageal reflux symptoms and erosive tooth wear on 261 participants. The predictors for ETW were age (+50) (OR 2.90, 95% CI: 1.83-6.00; p<0.0001), abnormal DeMeester score (OR 4.04, 95% CI: 0.95-17.15; p=0.05), inconclusive percentage of acid exposure time (OR 12.18, 95% CI: 3.10-47.84; p<0.0001), abnormal percentage of acid exposure time (OR 8.5, 95% CI:1.81-39.89; p=0.007) and daily regurgitation reported by patients (OR 2.90, 95% CI:0.89-6.39; p=0.01). No association was observed between oesophageal hypomotility disorders and erosive tooth wear. An in-vivo study assessed the total protein concentration of salivary film and acquired enamel pellicle from eroded and un-eroded tooth surfaces in 39 patients suffering from gastro-oesophageal reflux symptoms. No statistical difference was found when comparing eroded and un-eroded film/ acquired enamel pellicle from the same patient. However, when comparing those diagnosed with gastro-oesophageal reflux disease (GORD) and those without GORD, the acquired enamel pellicle total protein concentration was statistically lower in GORD patients compared to NO-GORD from both eroded (p=0.007) and un-eroded surfaces (p=0.008). These studies summarise predictors of erosive tooth wear in patients with GOR symptoms and provide an insight on the protective role of acquired enamel pellicle in these patients.

Date of Award	1 Aug 2021
Original language	English
Awarding Institution	King's College London
Supervisor	Rebecca Moazzez (Supervisor) & David Bartlett (Supervisor)