Dpto. Odontología

Purpose The airway complex is modified by palatine expansion. Computer tomography has been used in the past to determine the change in volume, but there was a lack of a specific, reproducible method for this purpose. The present study sought to determine the accuracy, reproducibility, and repeatability of an innovative digital measurement technique for analyzing the volume of maxillary and nasal sinus airways following suture palatine expansion performed with the Hyrax disyuntor appliance. Methods Patients underwent preoperative and postoperative cone-beam computed tomography (CBCT) scans. The datasets were subsequently uploaded into a digital treatment planning software to record the volume of the right and left maxillary sinus, as well as the nasal and maxillary sinus airway complex. The Gage Repeatability & Reproducibility statistical analysis methodology was used to evaluate the repeatability and reproducibility of this measurement technique when measuring the volume of maxillary and nasal sinus airways following suture palatine expansion with the Hyrax disyuntor appliance. Additionally, comparative analysis between preoperative and postoperative measures was performed using Student’s t-test for statistical analysis. Results In 5 patients, paired t-tests found statistically significant differences before and after treatment in the volumes of the left maxillary sinus (p = 0.002), right maxillary sinus (p = 0.001), and nasal and maxillary sinus airway complex (p = 0.005) after suture palatine expansion with the Hyrax disyuntor appliance. Conclusion The proposed digital technique is an accurate, repeatable, and reproducible measurement technique for analyzing the volume of maxillary and nasal sinus airways following suture palatine expansion using the Hyrax disyuntor.

Objectives: The aim of this study was to perform a 8-year prospective clinical investigation on the survival rate of feldspathic ceramic veneers, as well as analyse the influence of the occlusal splint in patients with parafunctional bruxism. Methods: Three hundred and sixty-four veneers fabricated using conventional feldspathic ceramic were provided in 64 patients. The patient sample included 40 individuals with bruxism. During the follow-up period, the effect of wearing the occlusal splint on the incidence of failure (fracture and/or debonding) in patients with bruxism was also assessed. The survival rate of veneers was determined using the Kaplan-Meier estimator. Statistical significance was set at p<0.05 with a confidence interval of 95%. Results: The occurrence of fracture for the feldspathic veneers tested in this study was 7.7%, while only 1.9% of the total number of veneers debonded. The overall survival rate was 93.7% after 3 years, 91% after 5 years, and 87.1% after 8 years. Patients with bruxism using an occlusal splint showed a survival rate of 89.1% after 7 years, while the survival rate in patients with bruxism using no occlusal splint was 63.9% (p<0.05). Conclusion: This study confirmed that feldspathic veneers may represent a suitable clinical approach for indirect aesthetic restorations. Such a treatment may be an option also for those patients affected by bruxism, as long as they regularly wear an occlusal splint. However, patients with bruxism using no occlusal splint may still present a potential higher risk of failure and/or debonding.

Background: Orthodontic treatment with fixed appliances is associated with changes in oral microbiota, including increased Candida colonization. The Candida fungus can cause oral lesions and infections such as candidiasis and angular cheilitis, and is harmful to both the patient and the orthodontist. Poor hygiene facilitates the colonization of these microorganisms. The key aim was to quantify the colonization of C. albicans in patients prior to beginning orthodontic treatment, and during the treatment process. Material and Methods: A total of 124 patients (43 males and 80 females) with a mean age of 19.5 years, who required treatment with metal or aesthetic (ceramic) braces, were studied. Microbiological samples were taken from the oral cavity using the swab technique throughout the treatment and cultured on a Sabouraud Dextrose Agar plate and, if positive, cultured on a CHROMagar® Candida plate. Results: In contrast to other published studies, no statistically significant increase in C. albicans colonization was observed during the orthodontic treatment. The fixed appliances had no influence on the presence, absence or level of colonization by C. albicans and there were no significant differences between the different appliances studied. Conclusions: Our study showed that frequency of oral hygiene measures by study participants did not affect the rate of oral carriage of Candida in a statistically significant manner. This observation contrasted with published literature, which suggests that thorough brushing is important to prevent the build-up of Candida species.

The aim of this study was to construct a novel, repeatable, reproducible, and accurate measurement protocol for the area and volume of the remaining cement after removal of fixed multibracket appliances, the area and volume of remaining cement after cement removal, the area and volume of enamel removed after cement removal, and the volume of cement used to adhere fixed multibracket appliances. A total of 30 brackets were cemented and removed with over 30 extracted teeth embedded into three experimental models of epoxy resin. The models were scanned before and after bracket placement, bracket debonding, and polishing the remaining cement. The brackets were submitted to micro-computed tomography. The standard tessellation language digital files were aligned, segmented, and re-aligned using geomorphometric software. The digital measurement technique accuracy, repeatability, and reproducibility were analyzed using Gage R&R statistical analysis. The variability attributable to the area and volume measurement techniques of the total variability of the samples was 0.70% and 0.11% for repeatability, respectively, and 0.79% and 0.01% for reproducibility, respectively. The re-alignment procedure is a repeatable, reproducible, and accurate technique that can be used to measure the area and volume of the remaining cement after removal of fixed multibracket appliances, the area and volume of remaining cement after cement removal, the area and volume of enamel removed after cement removal, and the volume of cement used to adhere the fixed multibracket appliance.

Orthodontic adhesives with antimicrobial and remineralizing properties may be an alternative to control white spot lesions around brackets. The aim of this study is to develop an experimental orthodontic adhesive containing boron nitride nanotubes (BNNT) and alkyl trimethyl ammonium bromide (ATAB). Methacrylate (BisGMA and TEGDMA) monomers were used to formulate the adhesives. Four experimental groups were produced with the addition of 0.1 wt.% BNNT (GBNNT); 0.1 wt.% ATAB (GATAB); and 0.2 wt.% BNNT with ATAB (GBNNT/ATAB); in the control group, no fillers were added (GCtrl). The degree of conversion, cytotoxicity, softening in solvent, contact angle and free surface energy, antibacterial activity, shear bond strength, and mineral deposition were evaluated. Adhesives achieved degree of conversion higher than 50% and cell viability higher than 90%. GBNNT and GATAB adhesives exhibited reduced softening in solvent. Mean free surface energy was decreased in the GBNNT adhesive. Significant reduction in bacterial growth was observed in the GBNNT/ATAB. No statistical difference was found for shear bond strength. Mineral deposition was found in GBNNT, GATAB, and GBNNT/ATAB groups after 14 and 28 days. The addition of 0.2% BNNT/ATAB to an experimental orthodontic adhesive inhibited bacterial growth and induced mineral deposition without affecting the properties of the material.

One of the main objectives of orthodontic treatment is to achieve an esthetic smile. This study set out to analyze differences in the perception of smile esthetics among patients before and after receiving orthodontic treatment. 250 Spanish patients analyzed a single photograph in which, by means of computer software, midline diastema, black triangle, gingival margin of the left central incisor, and gingival (ªgummyº) smile were altered. Each patient analyzed these images before and after undergoing orthodontic treatment. Patients scored the photographs on a scale from 1 to 10. Statistical analyses of each group's level of perception were carried out, identifying significant differences in evaluations before and after treatment, and in relation to subjects' gender and age. Patients presented significant differences in the esthetic perception of midline diastema and gummy smile anomalies after they had completed orthodontic treatment. Gender influenced the perception of smile esthetics, whereby women were significantly more critical of midline diastema, black triangle and gingival margin of the upper central incisor than men. The age variable also showed significant differences in the perception of midline diastema and black triangle anomalies. The perception of smile esthetics of some dental anomalies changes as a result of orthodontic treatment. Gender influences the perception of some of the dental anomalies studied.