Preliminary Exploration of a Laser-Based Surface Microtexturing Strategy for Improving the Wear Resistance of Dentin: An In Vitro Study

Objective: Herein, a feasible strategy based on a femtosecond laser (fs-laser) was provided to decelerate dentin wear, and the effect of wear resistance improvement and its potential mechanism were explored. Background: Tooth wear is a common phenomenon that exists throughout life. While once dentin is exposed, it wears away very quickly. Decelerating tooth wear, especially dentin wear, is an important issue, but there is no ideal treatment. Materials and methods: Sixteen third molar dentin samples were randomly divided into the amalgam (N1 = 8) and polymer infiltrated ceramic network (PICN) (N2 = 8) groups. One half of the sample was used as the experimental object and the other for the blank self-control. Array microcavities were fabricated on the experimental parts of all the samples with an fs-laser and then filled with the corresponding materials. The experimental and control parts of all the samples were subjected to 3600 cycles of sliding wear tests with titanium balls. The coefficients of friction (COFs) of every friction pair and the temperature rise were recorded in real time. The wear volume and depth were measured by a laser confocal microscopy. Statistical differences of wear volume and depth between the experimental and self-control parts were calculated by paired t-test. The wear mode was observed with scanning electron microscopy (SEM). Results: The COFs in the two experimental groups were significantly decreased. The maximum temperature rise on the dentin surface was 2.0°C. The wear resistance in the amalgam and PICN groups was 4.48 and 3.53 times higher than blank dentin, respectively (p < 0.001). The SEM images showed fewer plough grooves and cracks in dentin after microtexturing. Conclusions: This method could significantly improve tooth wear resistance by reducing the COFs between the friction pairs and reducing the dentin's ploughing effect and provide new treatment ideas for slowing the loss of severely worn dentin.