Our understanding of erosive tooth wear and its contributing factors has evolved considerably over the last decades. New terms have been continuously introduced, which frequently describe the same aspects of this condition, whereas other terms are being used inappropriately. This has led to unnecessary confusion and miscommunication between patients, professionals, and researchers. A group of 15 experts, selected by the European Organization for Caries Research (ORCA) and the Cariology Research Group of the International Association for Dental Research (IADR), participated in a 2-day workshop to define the most commonly used terms in erosive tooth wear. A modified Delphi method was utilized to reach consensus. At least 80% agreement was achieved for all terms discussed and their definitions related to clinical conditions and processes, basic concepts, diagnosis, risk, and prevention and management of erosive tooth wear. Use of the terms agreed on will provide a better understanding of erosive tooth wear and intends to enable improved communication on this topic.

The advantages, limitations and potential applications of available methods for studying erosion of enamel and dentine are reviewed. Special emphasis is placed on the influence of histological differences between the dental hard tissue and the stage of the erosive lesion. No method is suitable for all stages of the lesion. Factors determining the applicability of the methods are: surface condition of the specimen, type of the experimental model, nature of the lesion, need for longitudinal measurements and type of outcome. The most suitable and most widely used methods are: chemical analyses of mineral release and enamel surface hardness for early erosion, and surface profilometry and microradiography for advanced erosion. Morphological changes in eroded dental tissue have usually been characterised by scanning electron microscopy. Novel methods have also been used, but little is known of their potential and limitations. Therefore, there is a need for their further development, evaluation, consolidation and, in particular, validation.

Our aim was to investigate the effect of TiF4 solutions on mineral loss on enamel and dentine in vitro. Samples were fluoridated 1 × 5 min per day with 1.64% w/v TiF4 or 2.2% w/v NaF solutions, each with a pH of 1.2, and then subjected to a cyclic de- and remineralization procedure for 5 days. Demineralization was performed for 6 × 10 min per day with citric acid (pH 2.3). In controls no fluoridation was performed. Mineral content was determined by longitudinal microradiography. Enamel mineral loss was markedly reduced by both fluoride solutions, but TiF4 was significantly more effective than NaF: cumulative mineral loss on day 3 was 61.7 ± 15.0 µm in the NaF and 34.2 ± 13.1 µm in the TiF4 group (p ≤ 0.001) compared with 121.0 ± 27.0 µm in the control group. Dentine mineral loss ceased after both TiF4 and NaF applications (cumulative mineral loss on day 5 in controls: 61.0 ± 17.0 µm, in the TiF4 group: 15.4 ± 13.4 µm and in the NaF group: 21.8 ± 11.8 µm). Both TiF4 and NaF application reduced mineral loss both on enamel and dentine, which could open new possibilities for a symptomatic therapy of erosions.

The aim of this study was to evaluate the effects of an experimental tin-containing fluoride solution on erosive tissue loss in human enamel and dentine using a cyclic de- and remineralization model in situ. The study was a three-cell (7 days each) crossover design involving 20 healthy volunteers. Samples were mounted on buccal shields of mandibular mouth appliances and worn for 24 h, except during meals and oral hygiene. Samples were demineralized extraorally with 0.05 M citric acid (pH 2.3) for 6 × 5 min per day. Fluoride treatment was performed intraorally once per day for 30 s after the first demineralization. Three solutions were used: placebo (negative control); NaF solution (positive control, 1,000 mg/kg F, pH 4.5), and an experimental solution (1,900 mg/kg Sn as SnCl2, 500 mg/kg F as NaF, 500 mg/kg F as amine fluoride, pH 4.5). Tissue loss was determined profilometrically. In enamel, tissue loss was 33.6 ± 15.4 μm in the negative control group, 24.2 ± 9.2 μm (p ≤ 0.05) in the positive control group and 9.2 ± 3.4 μm (p ≤ 0.001) in the experimental solution group. The respective values for dentine were 47.8 ± 15.5 μm in the negative control group, 34.1 ± 9.3 μm (p ≤ 0.001) in the positive control group and 23.9 ± 6.4 μm (p ≤ 0.001) in the experimental solution group. The tin-containing solution was very effective in inhibiting erosive mineral in enamel in situ, even under severe conditions and with short application times, but was less effective in dentine.

Dental erosion is the non-carious dental substance loss induced by direct impact of exogenous or endogenous acids. It results in a loss of dental hard tissue, which can be serious in some groups, such as those with eating disorders, in patients with gastroesophageal reflux disease, and also in persons consuming high amounts of acidic drinks and foodstuffs. For these persons, erosion can impair their well-being, due to changes in appearance and/or loss of function of the teeth, e.g., the occurrence of hypersensitivity of teeth if the dentin is exposed. If erosion reaches an advanced stage, time- and money-consuming therapies may be necessary. The therapy, in turn, poses a challenge for the dentist, particularly if the defects are diagnosed at an advanced stage. While initial and moderate defects can mostly be treated non- or minimally invasively, severe defects often require complex therapeutic strategies, which often entail extensive loss of dental hard tissue due to preparatory measures. A major goal should therefore be to diagnose dental erosion at an early stage, to avoid functional and esthetic impairments as well as pain sensations and to ensure longevity of the dentition.

Objective. To investigate the efficacy of an experimental tin- and fluoride-containing mouth rinse on progression of erosion in enamel and dentine in vitro. Material and methods. Human enamel and dentine specimens were subjected to a cyclic demineralization and remineralization procedure for 10 days, with six 5-min demineralization periods per day. Erosive demineralization was performed with 0.05 M citric acid (pH 2.3). Except in the negative control group, the specimens were treated for 2 min with mouth rinses after the first and sixth demineralizations. An experimental tin-containing fluoride mouth rinse [125 mg/kg F^– (amine fluoride), 375 mg/kg F^– (NaF), 800 mg/kg Sn²⁺ (SnCl₂)] and an experimental sodium fluoride mouth rinse (500 mg/kg F^–) were used (both pH 4.5). A commercially available, tin-containing mouth rinse served as a positive control (pH 4.2, 409 mg/kg Sn²⁺, 250 mg/kg F^–). Tissue loss was determined profilometrically. Results. The highest tissue loss was found in the negative control group, in both enamel and dentine. In enamel, the NaF solution showed almost no effect. Both tin-containing solutions significantly reduced tissue loss (positive control: 65%; 800 mg/kg Sn²⁺: 78%; both p ≤ 0.001 compared to negative control). In dentine all mouth rinses significantly reduced tissue loss (positive control: 43%; 800 mg/kg Sn²⁺: 53%; NaF: 40%; all p ≤ 0.001 compared to negative control). Conclusions. In enamel, the efficacy of mouth rinses depended on the compound used; tin-containing preparations were notably effective. In dentine, however, reduction of substance loss was nearly the same in all treatment groups.