Professional perspective
Clinical relevance
- Differential diagnosis against caries, abrasion, and attrition
- Dietary history to identify acid sources and consumption patterns
- Assessment of possible gastric causes (reflux, recurrent vomiting)
- Standardized progress documentation for early detection of progression
Classification: BEWE
The Basic Erosive Wear Examination (BEWE, Bartlett et al., 2008) is an internationally established screening instrument, among several indices used to assess tooth wear. The mouth is divided into six sextants; the most severely affected surface in each sextant is scored on a four-point scale (0 to 3). The sum of the sextant maximum scores yields a total score, which maps to risk categories and corresponding measures. BEWE supports standardized monitoring but does not replace overall clinical judgment. The index was deliberately kept simple, so it can be recorded in daily practice about as quickly as the Periodontal Screening Index.
A 2026 update (Bartlett, O'Toole, Chen, et al.) introduces BEWE 2.0, adding an additional level for more severe erosive tooth wear and clarifying the distinction between scores 0 and 1. Other tooth wear indices, such as the Tooth Wear Evaluation System (TWES 2.0), are also used, particularly where more surface-specific detail is needed; the choice of index depends on the clinical or research purpose.
Mechanism
The erosive potential of an acid exposure depends, alongside pH, on factors including titratable acidity, mineral composition, and the degree of saturation relative to tooth hard tissue. The ability of certain acids to bind calcium can also play a role. A low pH value alone therefore does not reliably predict erosive potential; two beverages with similar pH can differ substantially in their erosive effect.
Current research: timing of brushing
A 2024 scoping review (Fernández et al.) evaluated 17 studies (1991 to 2022) on the timing of toothbrushing relative to acid exposure. The majority of studies (10 of 17) found no increased erosive tissue loss from brushing immediately with fluoride toothpaste, regardless of timing. Only a few studies supported delaying brushing by up to an hour. An accompanying systematic review also found differing results between bovine and human enamel: delayed brushing reduced tissue loss in bovine enamel, but not in human enamel. Part of the older evidence base underlying the classic 30-minute rule relies on such animal models. The findings suggest that the traditional blanket rule may need to be reconsidered in favor of more individualized guidance, though an international consensus to that effect is not yet in place.
What current evidence does not show
- No robust clinical trials (RCTs) on optimal brushing timing for erosion risk; available evidence relies predominantly on in situ and in vitro models
- No unified international guideline recommendation on brushing timing after acid exposure; existing recommendations are inconsistent
- No established German S-level guideline document specifically for dental erosion, unlike caries prevention (AWMF 083-021)
Evidence summary
What current evidence supports
- Dental erosion is mechanistically well distinguished from caries: direct chemical dissolution versus biofilm-mediated, critical-pH-dependent demineralization
- The BEWE index (Bartlett et al., 2008; updated 2026) is an internationally established, validated screening tool for erosive tooth wear severity, alongside other indices such as TWES 2.0
- Erosive potential depends on more than pH alone, including titratable acidity and mineral content, a mechanism well supported in the literature
- A 2024 scoping review (Fernández et al.) found that the majority of evaluated studies do not support delaying toothbrushing after acid exposure when using fluoride toothpaste
Why this matters
Because erosion is driven by direct chemical dissolution rather than bacterial acid production, the preventive levers differ from caries: dietary acid frequency and gastric causes matter more than biofilm control alone. The 2024 scoping review's findings suggest that the traditional blanket rule on brushing timing may need to be reconsidered in favor of more individualized guidance, though international consensus has not yet caught up with this shift.
What remains uncertain
- Optimal brushing timing has not been established through robust clinical trials in humans; current evidence relies mainly on in situ and in vitro models
- How findings from bovine enamel models, which underlie part of the traditional 30-minute rule, should be weighted against human-specific data showing different results
- When and whether international guidelines will formally shift toward individualized, risk-based brushing-timing recommendations
Bartlett, Ganss, Lussi (2008): Basic Erosive Wear Examination (BEWE): a new scoring system for scientific and clinical needs. Clinical Oral Investigations, 12(Suppl 1), S65-S68. Establishes the original, widely used international screening index for erosive tooth wear.
Bartlett, O'Toole, Chen, et al. (2026): BEWE 2.0: Basic erosive tooth wear examination revisited: Introducing an additional level for more severe erosive tooth wear. Journal of Dentistry, 166, 106514. Introduces an additional severity level and refines the distinction between scores 0 and 1.
Fernández, Silva-Acevedo, Padilla-Orellana, Zero, Carvalho, Lussi (2024): Should we wait to brush our teeth? A scoping review regarding dental caries and erosive tooth wear. Caries Research, 58(4), 454-467. Scoping review of 17 studies; challenges the traditional delayed-brushing recommendation and calls for individualized, risk-based guidelines.
