The purpose of this study was to compare disinfection and the biofilm removal efficacy of the GentleWave System (Sonendo, Inc., Laguna Hills, CA, USA) with passive ultrasonic activation method. Forty-seven freshly extracted human molars were inoculated with Enterococcus faecalis and cultured for five weeks to establish biofilm. Eight molars were tested for confirmation of infection. Four of the eight teeth were not inoculated in order to provide a negative control. The remaining 39 inoculated molars were randomly separated into three treatment groups (n = 13 per group): Group 1—no treatment, Group 2—conventional rotary instrumentation and passive ultrasonic activation, and Group 3—minimal instrumentation and the GentleWave System treatment. Roots were subsequently prepared per standard histological tissue processing procedures. Modified Brown and Brenn stained sections and Hematoxylin and Eosin stained sections were visualized at 4× and 13.5× magnification using a stereomicroscope. The sections were scored and blindly analyzed by two independent evaluators, including a histopathologist, to evaluate the presence of biofilm on canal wall. A significant difference was found between Group 2 and Group 3 in both apical and middle regions (p = 0.001) of the mesial roots of mandibular molars and mesiobuccal roots of maxillary molars. Group 3 revealed significantly less biofilm than the controls (p = 0.003). The GentleWave System demonstrated significantly greater reduction in biofilm within the mesial roots of mandibular molars and mesiobuccal roots of maxillary molars than those treated with conventional rotary instrumentation and passive ultrasonic activation protocol.

Objective The aim of this retrospective study was to assess the midfacial soft tissue changes following maxillary expansion using micro-implant-supported maxillary skeletal expanders (MSEs) in young adults by cone-beam computerized tomography (CBCT) and to evaluate the correlations between hard and soft tissue changes after MSE usage. Methods Twenty patients (mean age, 22.4 years; range, 17.6–27.1) with maxillary transverse deficiency treated with MSEs were selected. Mean expansion amount was 6.5 mm. CBCT images taken before and after expansion were superimposed to measure the changes in soft and hard tissue landmarks. Statistical analyses were performed using paired t -test and Pearson’s correlation analysis on the basis of the normality of data. Results Average lateral movement of the cheek points was 1.35 mm (right) and 1.08 mm (left), and that of the alar curvature points was 1.03 mm (right) and 1.02 mm (left). Average forward displacement of the cheek points was 0.59 mm (right) and 0.44 mm (left), and that of the alar curvature points was 0.61 mm (right) and 0.77 mm (left) ( p < 0.05). Anterior nasal spine (ANS), posterior nasal spine (PNS), and alveolar bone width showed significant increments ( p < 0.05). Changes in the cheek and alar curvature points on both sides significantly correlated with hard tissue changes ( p < 0.05). Conclusions Maxillary expansion using MSEs resulted in significant lateral and forward movements of the soft tissues of cheek and alar curvature points on both sides in young adults and correlated with the maxillary suture opening at the ANS and PNS.