Cup-Shaped Tooth Wear Defects: More than Erosive Challenges?

Abstract

Background/Aim: The underlying mechanism of the development of cups and grooves on occlusal tooth surfaces is still unclear. The aim of this study was to evaluate factors contributing to in vitro cup formation, in order to elucidate the clinical process. Methods: A total of 48 extracted human molar teeth were exposed to acidic aqueous solutions at pH of 4.8 and 5.5 in constant motion, in combination with different loading conditions: no load (0N group, control), 30 N (30N group) or 50 N (50N group) (n = 8 per group). Before and after 3 months of exposure (1,422,000 loading cycles), the samples were scanned using a non-contact profilometer. Pre- and post-exposure scans were subtracted and height loss and volume tissue loss were calculated. Representative samples with wear and cupping lesions were imaged using scanning electron microscopy, light microscopy and micro-computed tomography. Results: Average height and volume tissue loss at pH 5.5 was 54 µm and 3.4 mm³ (0N), 52 µm and 3.4 mm³ (30N) and 58 µm and 3.7 mm³ (50N), respectively, with no statistically significant differences. Average height and volume loss at pH 4.8 were 135 µm and 8.7 mm³ (0N), 172 µm and 12.6 mm³ (30N) and 266 µm and 17.8 mm³ (50N), respectively, with a statistically significant difference between 0N and 50N (p < 0.002). Cup-shaped lesions had formed only at pH of 4.8, in the 30N and 50N groups. Conclusion: The study showed that a cup can arise fully in enamel and that mechanical loading in addition to erosive challenges are required.

Intraoral scanner-based monitoring of tooth wear in young adults: 12-month results

“…However, it is unclear whether cupped lesions expose the dentine. Rather, in vitro studies have shown that the bottom of cupped lesions can also be located in the enamel [ 29 ]. Similar results were observed in an electron microscopic study with replicas of cupped lesions in patients [ 10 ].…”

Chipping and wear patterns in extant primate and fossil hominin molars: ‘Functional’ cusps are associated with extensive wear but low levels of fracture

“…In addition, functional cusps usually occlude into a fossa, potentially allowing additional support during compared with nonfunctional cusps (Cavel, 1985). Various behavioral factors may also influence chipping and wear patterns, with many species having developed specialized ways to minimize damage (Hatt et al, 2019;Hatt et al, 2019;Schulz-Kornas et al, 2019;Nakamichi et al, 1998;Allritz et al, 2013;Ito et al, 2017;Ruben et al, 2019). The present results indicate interspecific behavioral and dietary differences do not affect the overall relationship between nonfunctional cusps and enamel chipping, to suggest a strong phylogenetic (morphological or masticatory) influence.…”

Effect of masseter muscle activity during wakefulness and sleep on tooth wear

“…Second, a history of reflux esophagitis and frequent consumption of acidic foods was confirmed only by inquiry. According to an in vitro study using extracted teeth, an increase in dental attrition affecting the enamel was observed at a pH of 4.8, but not at pH 5.5 [40]. Tooth wear of the enamel may be greatly influenced by bruxism under low pH conditions, and further investigation is needed.…”