With the rapid development of implantable biomaterials, the rising risk of bacterial infections has drawn widespread concern. Due to the high recurrence rate of bacterial infections and the issue of antibiotic resistance, the common treatments of peri-implant infections cannot meet the demand. In this context, stimuli-responsive biomaterials have attracted attention because of their great potential to spontaneously modulate the drug releasing rate. Numerous smart bacteria-responsive drug delivery systems (DDSs) have, therefore, been designed to temporally and spatially release antibacterial agents from the implants in an autonomous manner at the infected sites. In this review, we summarized recent advances in bacteria-responsive DDSs used for combating bacterial infections, mainly according to the different trigger modes, including physical stimuli-responsive, virulence-factor-responsive, host-immune-response responsive and their combinations. It is believed that the smart bacteria-responsive DDSs will become the next generation of mainstream antibacterial therapies.

Background: The maxillary anterior teeth play a crucial role in smile aesthetics. Previous studies regarding the importance of maxillary lateral incisors for smile aesthetics concentrated on their size, incisor edge level, and inclination, etc. However, the aesthetic effect of lateral incisor movement in the spatial position has not been studied yet. Therefore, the purpose of this study was to explore the influence of the labiolingual position of maxillary lateral incisors on the aesthetic perception of smiles by orthodontists and laypersons, as well as analyze differences in this perception between male and female raters.Methods: A three-dimensional (3D) dental model was generated from the photograph of a man’s smile using iOrtho7.0 software (Time Angel, Wuxi, China). Based on this model, seven images were generated with different labiolingual positions of the maxillary lateral incisors in 0.5 mm increments (+ indicating labial translation, and—indicating lingual translation). The images were evaluated by 86 orthodontists and 161 laypersons using a visual analog scale, with lower scores indicating less attractiveness. Data were analyzed using Student’sttest and one-way analysis of variance with post hoc test.Results: There was no significant difference in smile ratings by males and females. Orthodontists assigned lower scores to all images than laypersons. The smile at + 1.5 mm was considered the least attractive by orthodontists, while smiles at + 1.5 mm and − 1.5 mm were regarded as the least attractive by laypersons. The smile at 0 mm was evaluated as the most attractive by all raters. Laypersons gave different scores to smiles at 0 or − 0.5 mm, but orthodontists did not.Conclusions: The labiolingual position of maxillary lateral incisors does affect the perception of smile aesthetics. Orthodontists may rate smile aesthetics more critically than laypersons. Therefore, communication and discussion between orthodontists and patients is needed to achieve better therapeutic and aesthetic outcomes.