The review aimed at analyzing the evidence available on 3D printable materials and techniques used for the fabrication of orthodontic appliances, focusing on materials properties that are clinically relevant. MEDLINE/PubMed, Scopus, and Cochrane Library databases were searched. Starting from an initial retrieval of 669 citations, 47 articles were finally included in the qualitative review. Several articles presented proof-of-concept clinical cases describing the digital workflow to manufacture a variety of appliances. Clinical studies other than these case reports are not available. The fabrication of aligners is the most investigated application of 3D printing in orthodontics, and, among materials, Dental LT Clear Resin (Formlabs) has been tested in several studies, although Tera Harz TC-85 (Graphy) is currently the only material specifically marketed for direct printing of aligners. Tests of the mechanical properties of aligners materials lacked homogeneity in the protocols, while biocompatibility tests failed to assess the influence of intraoral conditions on eluents release. The aesthetic properties of 3D-printed appliances are largely unexplored. The evidence on 3D-printed metallic appliances is also limited. The scientific evidence on 3D printable orthodontic materials and techniques should be strengthened by defining international standards for laboratory testing and by starting the necessary clinical trials.

Objective: To investigate the long-term influence of fixed lingual retainers on the development of mandibular gingival recession and to compare the prevalence with untreated individuals. Materials and Methods: The material consisted of 144 subjects: 96 orthodontically treated patients followed for 5 years after therapy and 48 untreated age-matched subjects. The treated patients were divided in two groups: one receiving a fixed mandibular retainer (n = 48) and one receiving no form of retention in the mandible (n = 48). The presence or absence of gingival recession and calculus accumulation were scored before treatment (T0), after debonding (T1), and 5 years after debonding (T5) for each tooth in the mandibular intercanine region using plaster models and intraoral photographs. The chi-square test, one-way ANOVA, and Cochran's Q test were used to evaluate inter- and intragroup differences. Results: The prevalence of patients with recession increased gradually and significantly throughout the observation periods in all groups, but the intergroup differences at T5 were not significant. Significantly more calculus accumulation was observed at T5 in the retainer group compared with the group without retainers. Conclusions: Long-term presence of fixed lingual retainers does not seem to increase the development of mandibular gingival recession, but does increase calculus accumulation.

Introduction. Forces generated in orthodontic treatment with fixed appliances create tension and compression zones in the periodontal ligament resulting in a painful experience for patients. In the first phase of orthodontic treatment, when leveling of teeth is needed, nickel-titanium (NiTi) archwires can be completely engaged in brackets, even in the cases of extreme crowding, exerting small forces. There is a great individual variation in the pain perception related to the application of orthodontic forces. Objective. The aim of this study was to investigate the pain perception among patients with dental crowding after insertion of six different NiTi orthodontic archwires as a part of fixed appliances in the first stage of orthodontic treatment. Methods. The study was conducted on a sample of 189 orthodontic patients receiving one of six different either superelastic or heat activated NiTi archwires, in the first phase of orthodontic treatment. Pain perception was evaluated in groups of patients with different degree of crowding. The modified McGill Pain Questionnaire with Visual Analogue Scale was used to evaluate the quality and intensity of pain. Statistical analysis was performed using simple descriptive statistics, and Pearson`s chi-square test with statistical significance of p<0.05. Results. Majority of patients reported pain as discomfort or pressure of moderate intensity caused by chewing or biting, started within 12 hours, carried on for 3-4 days, and decreased over time without self-medication. Conclusion. No correlation was found between pain perception among patients with different types of NiTi archwires and the degree of crowding.

Introduction. Therapy with fixed orthodontic appliances starts with bracket bonding and ends with debonding of brackets, leaving enamel surface varied. Objective. The aim of this pilot study was to examine enamel surface before and after debonding of orthodontic brackets by the use of scanning electron microscopy (SEM). Methods. Epoxy replicas of four patients? premolars indicated for therapy with fixed orthodontic appliances were made and brackets were bonded to their teeth with a different adhesives (Enlight, No-mix, Fuji Ortho LC and Heliosit Orthodontic) (n=4). Two months later, brackets on premolars were debonded and amounts of adhesive left on the tooth surfaces and the bracket bases were evaluated with the adhesive remnant index (ARI). After resin removal, epoxy replicas were made and the surface of premolars was evaluated with the enamel surface index (ESI). All replicas of premolars (n=32) were prepared for SEM examination and compared under different magnifications. Tooth damage was estimated based on correlation between ARItooth and ESI. Results. Pearson?s ?2 test showed no significant differences between ARItooth and ARIbracket of four materials used. Nonparametric correlations showed significant differences between ARItooth and ARIbracket, ESI and ARItooth, and between ESI and ARIbracket. Increasing of ARItooth is followed with the descent of ARIbracket and the ascent of ESI. Multivariate regression analysis showed a significant correlation between ESI and ARItooth. Conclusion. Most bond failures took place at enamel-adhesive interface. ARItooth was a predictor to enamel surface damage. The type of material did not affect enamel surface damage.

Introduction: Dentofacial disorders may potentially significantly affect the quality of life. Objectives of this study were to validate translated and culturally adapted Orthognatic Quality of Life Questionnaire (OQLQ) on a cohort of Serbian patients with malocclusions. Methods: The questionnaire was validated in 111 consecutive patients with malocclusions, seen between December 2014 and February 2015 at the Clinic of Orthodontics, Faculty of Dental Medicine, University of Belgrade. Clinical validity was assessed comparing the mean scores for the four subscales of the OQLQ and mean PAR pre-treatment score. In order to assess whether the allocation of items in the subscales corresponds to their distribution in the original questionnaire, an exploratory factor analysis (principal component analysis with varimax rotation) was conducted. Results: The results of the internal consistency analysis demonstrated good relationships between the items; Cronbach’s alpha coefficients for the four subscales were highly significant (p<0.001) (0.88-0.91). All items were significantly correlated between baseline and the retest (6 weeks after). The correlations between the PAR and all four domains of the OQLQ were all significant (p<0.01). The loading weights obtained in the exploratory factor analysis showed that this model revealed four factors with eigenvalue greater than 1, explaining the 64.0% of the cumulative variance. The majority of the items (86.4%) in the Serbian version of the OQLQ presented the highest loading weight in the subscales assigned by the OQLQ developer. Conclusions: The psychometric properties of the OQLQ (Serbian version) have exceptional internal consistency and reproducibility as an instrument for evaluation of dental malocclusions. Additionally, this questionnaire may be useful as a supplementary outcome measure in persons with malocclusions.