Background: Due to the declining prevalence of dental caries, noncarious tooth defects such as erosive tooth wear have gained increased attention over the past decades. While patients more frequently search the internet for health-related information, the quality of patient-centered, web-based health information on erosive tooth wear is currently unknown.

Objective: This study aimed to assess the quality of patient-centered, web-based health information (websites and YouTube videos) on erosive tooth wear.

Methods: German-language websites were systematically identified through 3 electronic search engines (google.de, bing.de or yahoo.de, and duckduckgo.com) in September 2021. Eligible websites were independently assessed for (1) technical and functional aspects via the LIDA instrument, (2) readability via the Flesch reading-ease score, (3) comprehensiveness of information via a structured checklist, and (4) generic quality and risk of bias via the DISCERN instrument by 2 different reviewers. An overall quality score (ie, higher scores being favored) generated from all 4 domains was used as the primary outcome. Quality scores from each domain were separately analyzed as secondary outcomes and compared by the Friedman test. The effect of practice-specific variables on quality scores of websites from private dental offices was assessed using generalized linear modeling. Eligible YouTube videos were judged based on (1) the comprehensiveness of information, (2) viewers' interaction, and (3) viewing rate. The comprehensiveness of information was compared between websites and YouTube videos using the Wilcoxon rank-sum test.

Results: Overall, 231 eligible websites and 7 YouTube videos were identified and assessed. The median overall quality of the websites was 33.6% (IQR 29.8%-39.2%). Secondary outcome scores amounted to 64.3% (IQR 59.8%-69.0%) for technical and functional aspects, 40.0% (IQR 34.0%-49.0%) for readability, 11.5% (IQR 3.9%-26.9%) for comprehensiveness of information, and 16.7% (IQR 8.3%-23.3%) for generic quality. While the comprehensiveness of information and generic quality received low scores, technical and functional aspects as well as readability resulted in higher scores (both P_adjusted<.001). Regarding practice-specific variables, websites from private dental offices outside Germany (P=.04; B=-6.64, 95% CI -12.85 to -0.42) or from dentists who are a dental society member (P=.049; B=-3.55, 95% CI -7.09 to -0.01) resulted in lower readability scores (ie, were more difficult to read), while a shorter time since dentists' examination resulted in higher readability scores (P=.01; B=0.24 per year, 95% CI 0.05-0.43). The comprehensiveness of information from YouTube videos was 34.6% (IQR 13.5%-38.5%). However, the comprehensiveness of information did not vary between websites and YouTube videos (P=.09). Additionally, viewers' interaction (1.7%, IQR 0.7%-3.4%) and viewing rates (101%, IQR 54.6%-112.6%) were low.

Conclusions: The quality of German-language, patient-centered, web-based information on erosive tooth wear was limited. Especially, the comprehensiveness and trustworthiness of the available information were insufficient. Web-based information on erosive tooth wear requires improvement to inform patients comprehensively and reliably.