This is an author version of the contribution published on:Questa è la versione dell 'autore dell'opera: J Oral Maxillofac Surg. 2014 Oct;72(10):1890-7. doi: 10.1016/j.joms.2014 AbstractPurpose: The surgical removal of mandibular third molars is frequently accompanied by significant post-surgical sequelae, and different protocols have been described to improve such adverse events. The aim of this study was to investigate the performance of piezosurgery compared with traditional rotating instruments during mandibular third molar removal. Methods:A single-centre, randomized, split-mouth study was performed using a consecutive series of unrelated healthy Caucasian patients, attending the Oral Surgery Unit of the University of Turin, for surgical removal of bilateral mandibular third molar teeth. Each patient was treated, at the same appointment, using bur removal on one side of the mandible and a piezoelectric device on the contralateral side. The primary outcomes reported were postoperative pain, objective orofacial swelling and the duration of surgical time; secondary outcomes were sex, age and possible adverse events. Anova or paired t-test were used as appropriate to test any significant differences at baseline according to each treatment subgroups and categorical variables were analysed by χ2 test.Results: The study sample consisted of 100 otherwise healthy patients. The mean pain evaluation reported by patients who underwent surgery with the piezosurgery was significantly lower than that experienced after bur (conventional) removal, reaching a statistical difference after 4 days (P=0.043). The clinical value of orofacial swelling at 7th day, normalized to baseline, was lower in the piezosurgery group (P<0.005).The average time of surgery was significantly lower in the bur than piezosurgery group (P<0.05).Three patients having bur removal experienced short-term complications (two dry sockets and one temporary paraesthesia): both totally resolved by 4 weeks. Conclusions:To date, this prospective investigation is the largest reported split-mouth study on piezosurgery for lower third molar tooth removal, also comparing surgeons with different 3 degrees of experience. It is evident that using a piezoelectric device can enhance the patient experience and reduce post-operative pain and swelling.

PurposeThe aims of the study were: 1) to evaluate the fitting of three different aligners (Invisalign (Align Technology,

Invisalign and CA-Clear Aligner exhibited comparable fit on anchorage teeth. Invisalign provided better fit at the gingival edges of aligners, while the CA-Clear Aligner provided better fit on complex occlusal surfaces.

Objectives To measure the thickness homogeneity of Invisalign (Align Technology Inc, San José, Calif) aligners with micro-computed tomography (micro-CT) scans. Materials and Methods Starting from micro-CT scanning of 20 different aligners, multiplanar reconstructions were obtained. An orthodontist blinded about the study measured aligner thickness in different regions (molar, canine, incisor) and in different sites (gingival–buccal, buccal, occlusal, lingual, and gingival–lingual). To assess various thicknesses in different aligner sites and regions, the sample was stratified into subgroups and linear regression analysis was performed. Results Descriptive analysis showed that mean thickness of aligners in the incisor region ranged from 0.582 mm to 0.639 mm, in the canine region from 0.569 mm to 0.644 mm, and in the molar region from 0.566 mm to 0.634 mm. Student's t-tests showed no significant differences in the aligner thickness of different regions when data were stratified by different sites. Student's t-tests showed significant differences in thickness homogeneity for the molar region when the data were stratified by tooth (mean difference = 0.068 mm; 95% confidence interval, 0.009–0.126 mm; P = .024). Conclusions Invisalign aligner thickness is characterized by small differences. The only significant difference was revealed in the molar region where thickness of the gingival–lingual edge is significantly thinner than that measured at the occlusal aspect. From a clinical perspective, the results of the present study could be considered to explain the reduced predictability of several orthodontic tooth movements in the molar region.