Search Results (58)

Objectives: This study investigated the use of artificial intelligence (AI) in the design of lingual bracket indirect bonding trays and its association with bracket transfer accuracy using three-dimensional (3D) printing. Methods: Digital impressions of patient’s dental arches were captured using an intraoral scanner, and orthodontic setups were virtually constructed. Brackets were virtually positioned in their ideal locations using the digital setups guided by virtual archwire templates. Indirect bonding trays were automatically generated using the AI-powered Auto Creation function of the Medit Splints application, which analyzes anatomical features to streamline design. Bracket transfer accuracy was evaluated in vivo by comparing planned and actual bracket positions across grouped and individual tray configurations. Linear and angular deviations were measured using conventional 3D inspection software. Results: Most bracket transfer errors were within clinically acceptable thresholds, although torque accuracy remained suboptimal. Grouped trays generally exhibited greater precision than individual trays in several dimensions. Conclusions: These findings support the application of AI-assisted design tools to enhance digital workflows and improve consistency in appliance fabrication. Full article

Excessive mandibular growth is largely affected by genetic factors and its orthodontic management is challenging. The present study utilized histophotometry and aimed to investigate immunohistochemical alterations in rat condyles following posterior mandibular displacement using a fixed intraoral functional appliance. Seventy-two male Wistar rats were divided into two equal groups, experimental and control, each consisting of three equal subgroups. The animals were sacrificed after 30, 60, and 90 days, and their condyles were isolated and examined microscopically for potential immunohistochemical changes. Statistically significant differences in RANKL appeared at days 30 and 60, while noteworthy changes regarding TRAP were evidenced at days 30 and 90. In the experimental group, RANKL decreased statistically significantly between days 60 and 90, while in the control group, the RANKL measured significantly increased at day 90 compared to days 30 and 60 alike. In the experimental group, TRAP appeared significantly decreased at day 60 vs. 30, while at day 90 vs. 60, it was found to be significantly increased. In the control group, there were no significant changes in TRAP. Posterior mandibular displacement may cause immunohistochemical changes in the rat condylar bone, and such outcomes should be considered when planning similar procedures in humans. Full article

(1) Background: The intra-oral behavior of clear thermoplastic dental materials can be influenced by various intrinsic and extrinsic factors. Aim: The purpose of this in vitro study was to evaluate the optical properties, color changes and whiteness variations of four thermoplastic polymers used for dental appliances, in a simulated oral environment. (2) Methods: Customized thermoformed specimens of four PETG thermoplastics were selected and investigated in this study: Leone [L], Duran [D], Erkodur [E] and Crystal [C]. The thermoplastic samples were divided into three groups related to pH values (neutral, acidic and basic). A period of 14 days was simulated. Five stages resulted: I. dessicated specimens; II. hydrated in artificial saliva; III. subsequent desiccated; IV. artificial aged; V. further dessicated. Optical CIE L*a*b* coordinates were determined and optical properties, like TP (translucency), OP (opalescence) values, color differences ΔE-NBS, white indexes in dentistry WI_D and white index differences ΔWI_D were calculated for all stages of the study, for each group of the materials. Statistical analyses were performed. (3) Results: Optical properties of PETG clear thermoplastic materials, like TP and OP, increase in a simulated oral environment and the changes become significant after artificial aging. Related to pH values, the optical behavior between the materials is significantly different. During artificial aging, the tested materials behave significantly differently in terms of optical properties. (4) Conclusions: After the simulated period of 14 days, TP and OP values increase, with a migration of the color towards red and yellow. Color changes in some cases even reach the level of extremely marked. Whiteness increases, and the differences are mostly perceptible, but partially exceed the limit of acceptability. Full article

Background: The aim of the present study was to assess the accuracy, repeatability and reproducibility of a novel digital technique to analyze the remaining cement after debonding lingual multibracket appliances and after polishing the remaining cement. Methods: Thirteen teeth were embedded in an epoxy resin simulating a dental arch and subsequently a digital impression was taken using an intraoral scanner; obtaining a standard tessellation language (STL1) digital file. Lingual multibracket appliances were bonded and debonded on the lingual surfaces of all teeth and another digital impression was made (STL2). Finally, the polishing procedure of the remaining cement was performed and a digital impression was taken (STL3). The teeth were individually segmented from the digital files and an alignment was performed between STL1 and STL2 and between STL1 and STL3 digital files using specific cephalometric 2D/3D software to assess the remaining cement after debonding and after polishing lingual multibracket appliances. The reproducibility and repeatability capacity of the measurement digital method was assessed using a Gage R&R statistical analysis. Results: The results were assessed by a statistical program and showed a statistically significant (p < 0.001) decrease in weight, thickness, and height of the cement remaining after polishing, with a mean decrease of 2.09 mm in width (X plane), 0.12 mm in thickness (Y plane), and 1.87 mm in height (Z plane). Conclusions: The use of novel digital diagnosis software is a repeatable, reproducible, and accurate measurement technique to analyze the remaining cement after debonding lingual multibracket appliances and after polishing the remaining cement. Practical Implications: The diagnosis cephalometric software evaluation of the polishing technique with different materials, burs or polishing sequences brings the research closer to the clinical field. This methodology allows the orthodontist to clinically measure the cement remnants after polishing without the need for teeth extraction and with current clinic objects such as intraoral scanning and orthodontic cephalometric software. This might give orthodontics more clearance in terms of better burs or protocols for polishing. Full article

Class II malocclusions, characterized by the mesial positioning of the maxillary molars relative to the mandibular molars, are among the most frequently encountered orthodontic issues. One of the widely adopted non-extraction approaches for addressing this malocclusion is maxillary molar distalization, which has been utilized for decades to create space within the dental arch. Historically, extraoral appliances such as headgear were commonly employed. However, with technological advancements, intraoral distalization devices, particularly those incorporating temporary anchorage devices (TADs), have gained prominence due to their compact size, not being visible externally, and improved patient acceptance. These appliances offer significant advantages, including being less invasive compared with extraction-based camouflage treatments, being more readily accepted by patients due to the absence of extraction spaces, and not requiring the complex biomechanical principles involved in extraction-based methods. TADs have revolutionized distalization techniques by providing superior anchorage control, reducing treatment duration, and offering a straightforward, patient-friendly application. The purpose of this comprehensive narrative review is to focus specifically on intraoral distalization techniques utilizing TADs, summarizing their efficacy and outcomes in the management of Class II malocclusions as reported in clinical studies over the past three decades. Full article

Atypical swallowing has a high incidence in growing subjects. Orthopedic treatment with orthodontic appliances and speech therapy are the main approaches to this problem. The aim of this prospective study was to evaluate the changes in the dental arches induced by one year of treatment with the Froggy Mouth myofunctional appliance designed to correct atypical swallowing. In total, 16 patients with atypical swallowing were instructed to use the Froggy Mouth appliance. A digital intraoral impression was taken at baseline (T0). The Froggy Mouth appliance had to be used for 15 min/day throughout the treatment period. At the end of the first year of treatment (T1), another impression was taken with the same intraoral scanner. Digital casts of the T0 and T1 impressions were obtained using software and the two casts were superimposed to record the following measurements: upper intercanine distance, upper arch diameter, upper arch width, overbite and overjet. The data were statistically analyzed (significance threshold: p < 0.05). Student’s t-test was used to compare pre- and post-treatment measurements. Linear regressions were performed to assess the influence of arch width on anterior and posterior diameters. A significant increase was found for the upper arch diameters (p < 0.05), whereas no statistically significant difference was found for the incisor relationship (overjet/overbite) (p > 0.05). To date, the efficacy of this appliance has not been extensively studied. According to the present prospective study, the Froggy Mouth protocol could be a valuable method as a myofunctional therapy for atypical swallowing, but further studies are needed to confirm these preliminary results. Full article

Introduction: The need to permanently join two or more pieces of metal using heat is a frequent condition in various fields of medicine such as dentistry. Welding, brazing and soldering are permanent joining techniques between different metals that require in-depth background knowledge in order to obtain predictable results. Aim: This review examines the different methods of joining metals using heat and their fields of application. Discussion: It is possible to create permanent metal joints in various phases of the creation of final products that will be used on the patient. In several cases, welds are also made directly by the manufacturer during industrial processing. In dentistry, dental laboratories perform complex welds mainly on dental prostheses and orthodontic appliances during the production process. It is also possible to obtain intraoral welding carried out by the clinician inside the patient’s oral cavity. Welding can be carried out using combustible gases, electric current, infrared light and laser light through different technical procedures which must be chosen according to the specific needs and the metals to be joined. Conclusions: It is useful for the dentist and dental technician to know the different welding methods, including those carried out in the factory by the manufacturer, to better understand the physical properties and mechanical resistance of the components marketed for the construction of prostheses and orthodontic appliances. The enormous variety of conditions in which those who practice welding can find themselves therefore presupposes in-depth knowledge in this field in order to apply the most suitable technique. Full article

(1) Background: This study aims to investigate, within a controlled laboratory environment, the magnitude of the transversal load and the force decay over time produced by clear aligners in comparison to a Rapid Palatal Expander (RPE). (2) Methods: Resin models of a dental maxillary arch, additively manufactured from an intraoral scan, were inserted in a testing machine with uniaxial load cells to measure the force trend over time expressed by RPE and clear aligners. The mechanical load was recorded during a certain timeframe for both appliances. (3) Results: The force expressed by the RPE ranged from 30 to 50 N for each activation, decreasing with a nonlinear pattern over time. The force expressed by the clear aligner ranged from 3 to 5 N, decreasing with a linear pattern over time. In contrast, the force generated by the clear aligner fell within the range of 3 to 5 N, showing a linear reduction in force magnitude over the observed period of time. (4) Conclusions: The RPE exerted a force magnitude approximately ten times greater than that generated by clear aligners. Nevertheless, it is essential to acknowledge that the oral environment can significantly influence these results. These limitations underscore the need for caution when applying these findings to clinical settings. Full article

Due to dental diseases, anatomical restrictions, and mixed dentition, the reduction in the number of teeth and the displacement of tooth germs pose challenges in orthodontic treatment, limiting anchorage options. The presented case demonstrates an advanced treatment solution using digital CAD/CAM-technologies and medical imaging for the creation of a mini-implant template. A 12-year-old male patient experiencing delayed tooth eruption, multiple impacted germs, and maxillary constriction underwent intraoral scanning and CBCT. Utilizing coDiagnostiX^TM Version 10.2 software, the acquired data were merged to determine the mini-implant placement and to design the template. The template was then manufactured through stereolithography using surgical-guide material. Mini-implants were inserted using the produced appliance, enabling safe insertion by avoiding vital structures. Surgically exposed displaced teeth were aligned using a Hyrax screw appliance anchored on the mini-implants for rapid palatal expansion (RPE) and subsequently used as fixed orthodontics to align impacted teeth. The screw was activated daily for 10 weeks, resulting in a 7 mm posterior and 5 mm anterior maxillary transversal increase. Skeletal anchorage facilitated simultaneous RPE and tooth alignment, ensuring accuracy, patient safety, and appliance stability. The presented case shows a scenario in which computer-aided navigation for mini-implant positioning can enhance precision and versatility in challenging anatomical cases. Full article

The aim of this work was to analyze and compare the tooth structure removal between a free-hand preparation technique and a computer-aided preparation technique using an augmented reality appliance for complete-crowns preparation designs and “root mean square” (RMS) alignment value. Ten upper teeth representatives of all dental sectors were selected from a generic model library as “Standard Tessellation Language” (STL-1) digital files and 3D-printed in an anatomically based acrylic resin experimental model. Then these were randomly assigned to the following tooth preparation techniques: Group A: free-hand preparation technique (n = 5) (FHT) and Group B: computer-aided preparation technique using an augmented reality appliance (n = 5) (AR). Experimental models were submitted to a digital impression through an intraoral scan and (STL-2) uploaded into a reverse engineering morphometric software to measure the volumetric reduction in the planned and performed tooth structure (mm³) and RMS using the Student’s t-test and the Mann–Whitney non-parametric test. Statistically significant differences were observed between the volumetric reduction in the planned and performed tooth structure (mm³) of the AR and FHT study groups (p = 0.0001). Moreover, statistically significant differences were observed between the RMS of the planned and performed tooth preparations in both the AR and FHT study groups (p = 0.0005). The augmented reality appliance provides a more conservative and predictable complete-crowns preparation design than the free-hand preparation technique. Full article

The interaction of different dental alloys with the oral environment may cause severe side effects (e.g., burning sensation, inflammatory reactions, carcinogenesis) as a result of oral galvanism. However, the pathogenesis of side effects associated with oral galvanism is still unclear, and the effects of direct current and alloy corrosion ions are considered potentially contributing factors. Therefore, the aim of this study was to systemically compare the damaging effects of (1) galvanism as a synergistic process (direct current + corrosion ions), (2) direct current separately, and (3) corrosion ions separately on an in vitro mucosa-like model based on a cell line of immortalized human keratinocytes (HaCaTs) to reveal the factors playing a pivotal role in dental alloys side effects. For this, we chose and compared the dental alloys with the highest risk of oral galvanism: Ti64–AgPd and NiCr–AgPd. We showed that galvanic current may be the leading damaging factor in the cytotoxic processes associated with galvanic coupling of metallic intraoral appliances in the oral cavity, especially in the short-term period (28 days). However, the contribution of corrosion ions (Ni²⁺) to the synergistic toxicity was also shown, and quite possibly, in the long term, it could be no less dangerous. Full article

The orthodontic supply market is a prosperous billion-dollar industry, driven by an increasing demand for orthodontic appliances. The supremacy of metallic first-generation biomaterials is evident for manufacturing brackets, archwires, bands, and other components due to their well-recognized chemical inertness, spontaneous passivation, biocompatibility, and favorable mechanical properties combination. However, the oral cavity is the ultimate corrosion-promoting environment for any metallic material. In this work, the general picture of the intraoral degradation of fixed orthodontic appliances is first addressed, from the causes to the harmful effects and their oral clinical implications. Current mitigation strategies are also pointed out, including the alloys’ bulk composition adjustment combined with new and advanced manufacturing processes and/or their surface treatment or coating deposition. The versatile use of thin films and coatings stands out with different deposition technologies: Many in vivo and in vitro efforts have been devoted to oral aging, from monolithic to composite architectures and micro- to nano-scale materials, to meet the best and safest oral practice demands. Unfortunately, literature data suggest that even the existing commercially available protective coatings have drawbacks and are fallible. Further multidisciplinary research is still required to effectively mitigate the corrosion behavior of fixed orthodontic appliances. Full article

The tooth impaction of the lower second premolars is an occasional condition but is still seen in clinical practice with a prevalence of 0.6–2.6%. The present case report describes a rare condition of the lower second premolar impaction. An 11-year-old female patient presented with the anteroposterior dental discrepancy, midline shift, and occlusal cant. Intraoral examination revealed the absence of the lower right second premolar with no space available for the eruption. X-ray examination revealed the impaction of tooth #45 in a vertical position, tilting of the adjacent teeth, and two-thirds root length development. The orthodontic treatment plan included space opening using a fixed appliance with a coil spring. The natural eruption of the tooth was expected according to dental age and root development. When the space was opened, no change in the position of tooth #45 was observed. Surgical exposure and active traction were performed. However, the intrusion and tilting of adjacent teeth were observed during the next appointments with no vertical change of tooth #45. Ankylosis was suspected as no tooth movement was recorded. The surgical luxation and osteotomy of the coronal alveolar bone of the impacted tooth were planned for the imminent forced eruption, which was expected due to the young age of the patient. Consequently, the crown of tooth #45 emerged and the bracket was placed. Further traction was planned to use a micro-screw. Following the traction, no vertical displacement of the tooth was observed in the subsequent appointments. Radiographic examination revealed radiolucency in the coronal third of the root. The patient was referred to the endodontist, and CBCT revealed external cervical root resorption in the late reparative stage. ECR in an impacted tooth, mimicking the manifestation of tooth ankylosis, can cause orthodontic treatment failure. Full article

(1) Background: The aim of the present study is to analyze the instant postural changes and changes in the dystonic contractions among patients with dystonia following the use of an intraoral device called a key integrative dynamic TMJ treatment appliance (KIDTA). (2) Methods: Twelve subjects, previously diagnosed with dystonia were enrolled. Their existing records were utilized to assess the changes in their posture and dystonic contractions. The posture analysis was conducted using a mobile application (APECS). The initial records (T0) and records acquired after the delivery of the KIDTA (T1) were utilized in the analysis. The Wilcoxon signed-rank test was performed to compare parameters between T0 and T1, with a significance level set at p < 0.05. (3) Results: Based on the Wilcoxon signed-rank test, statistically significant differences in T1 compared to T0 were observed in the severity of dystonic spasms, body alignment, head shift, head tilt, shoulder alignment, shoulder angle, axillae alignment, ribcage tilt, pelvic tilt, knee angle, and tibia angle (p < 0.05). (4) Conclusions: Within the limitations of the present pilot study, an intervention to the TMJ through a KIDTA appliance seems to mitigate the severity of dystonic contractions and improve the posture with respect to certain postural parameters. Full article

Multi-bracket appliances have long been established as tools for treating malocclusions. However, the complex construction and difficulty in cleaning due to their long-term intraoral retention have hindered the prevention of caries and periodontitis. In this study, professional mechanical tooth cleaning (PMTC), including tooth-brushing instructions, was continuously performed for 3 months in 24 patients who had worn multi-bracket appliances for more than 6 months, and changes in the oral and gut microbiota were examined using one-way repeated-measures analysis of variance. Additionally, changes in bacterial flora associated with different treatment durations were verified using the Pearson correlation coefficient. The results showed that continuous PMTC significantly reduced the amount of plaque in the oral cavity. No significant changes were observed in the oral or gut microbiota and no significant increase in pathogenic bacteria was observed. Therefore, our results suggest that continuous PMTC during orthodontic treatment with multi-brackets may inhibit the growth of pathogenic bacteria by maintaining a clean oral environment and avoiding dysbiosis in both the oral and gut microbiota. Significant changes in the gut microbiota with different treatment durations suggested that differences in food intake and food choices at each treatment stage of orthodontic treatment may affect the gut microbiota. Full article