Search Results (148)

The aim of this study was to compare the forces and moments exerted by thermoformed aligners (TFMs) and direct printed aligners (DPAs) on the maxillary left central incisor (21) and adjacent teeth (11, 22) during lingual bodily movement of tooth 21. Methods: An in vitro setup was used to quantify forces and moments on three incisors, which were segmented and fixed onto multi-axis force/moment transducers. TFM were fabricated using 0.76 mm-thick single-layer PET-G foils (ATMOS; American Orthodontics, Sheboygan, WI, USA) and multi-layer TPU foils (Zendura FLX; Bay Materials LLC, Fremont, CA, USA). DPAs were fabricated using TC-85 photopolymer resin (Graphy Inc., Seoul, Republic of Korea). Tooth 21 was planned for bodily displacement by 0.25 mm and 0.50 mm, and six force and moment components were measured on it and the adjacent teeth. Results: TC-85 generated lower forces and moments with fewer unintended forces and moments on the three teeth. TC-85 exerted 0.99 N and 1.53 N of mean lingual force on tooth 21 for 0.25 mm and 0.50 mm activations, respectively; ATMOS produced 3.82 N and 7.70 N, and Zendura FLX produced 3.00 N and 8.23 N of mean lingual force for the same activations, respectively. Bodily movement could not be achieved. Conclusions: The force systems generated by clear aligners are complex and unpredictable. DPA using TC-85 produced lower, more physiological force levels with fewer side effects, which may increase the predictability of tooth movement and enhance treatment outcome. The force levels generated by TFM were considered excessive and not physiologically compatible. Full article

Introduction: Digital planning and evolution of technology is allowing dentistry to be more efficient in time than before. In orthodontics the main purpose is to obtain fewer patient visits and to reduce the bonding time. For that, indirect bonding planned with CAD-CAM softwares is used to obtain a shorter treatment period, in general, and less chair-time. This waste of chair-time should also be reduced in other fields of dentistry such as endodontics, surgery, prosthodontics, and aesthetics. Methods: A total of 504 teeth were embedded into epoxy resin models mounted as a dental arch. Customized lingual multibracket appliances were bonded by a current adhesion protocol. After that, they were debonded, the polishing of cement remnants was performed with three different burs and two drills. The polishing time of each group was recorded by an iPhone 14 chronometer. Results: Descriptive and comparative statistical analyses were performed with the different study groups. Statistical differences (p < 0.005) between diamond bur and tungsten carbide and white stone burs and turbine were obtained, with the first being the slowest of them. Discussion: Enamel roughness was widely studied in orthodontics polishing protocol as the main variable for protocols establishment. However, in lingual orthodontics, due the difficulty of the access to the enamel surfaces, the protocol is not clear and efficiency should be considered. It was observed that the tungsten carbide bur is the safest bur. It was also recommended that a two-step protocol of polishing by tungsten carbide bur be followed by polishers. Conclusions: A tungsten carbide bur mounted in a turbine was the most efficient protocol for polishing after lingual bracket debonding. Full article

Amorphous calcium phosphate (ACP) is a well-established bioceramic material known to promote the remineralization of dental hard tissues. White spot lesions (WSLs) represent the initial stage of enamel demineralization and are frequently observed in patients with fixed orthodontic appliances or inadequate oral hygiene. Although recommendations for remineralizing agents include both the prevention of lesion progression and the stimulation of tissue remineralization, the clinical efficacy of ACP-based materials remains under debate. This systematic review, registered in the PROSPERO database (CRD42024540595), aims to evaluate the clinical efficacy of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP)-based products in the remineralization of WSLs and to compare these outcomes with those achieved using non-bioceramic approaches. Inclusion criteria comprised randomized clinical trials, prospective cohort studies, and pilot studies conducted on human subjects with WSLs affecting permanent teeth. Studies involving artificial WSLs or non-cariogenic enamel lesions were excluded. The quality of the included studies was assessed using the Cochrane Risk of Bias 2 (RoB 2) tool. Fourteen articles met the inclusion criteria and were analyzed. The main findings indicate that CPP-ACP is clinically effective in promoting the remineralization of WSLs, although the results were inconsistent across studies. Comparisons with placebo and resin infiltration treatments revealed greater efficacy for CPP-ACP. The combination of CPP-ACP with fluoride appeared to further enhance the remineralizing effect on WSLs. Additional standardized clinical studies with longer follow-up periods are warranted to confirm these outcomes. Full article

Background/Objectives: The increasing clinical integration of 3D-printed definitive resins requires a comprehensive understanding of their physicochemical properties and adhesive behavior. However, there is limited evidence regarding the optimal surface treatment and bonding strategies for clear aligner composite attachments on these materials. This study aimed to characterize a 3D-printed definitive resin, evaluate the effects of surface treatments on its surface topography, and compare the shear bond strength (SBS) of the bonded attachments using different adhesive systems, both before and after thermocycling. Methods: A total of 120 rectangular specimens were fabricated from a 3D printed dental resin (Crowntec^®, SAREMCO Dental AG—Mexico City, Mexico). For physicochemical characterization, six samples underwent scanning electron microscopy/energy-dispersive spectroscopy, X-ray diffraction, and thermogravimetric analysis. To evaluate surface topography, 42 polished specimens were assigned to three groups: untreated (control), etched with 4% hydrofluoric acid (HFA), or sandblasted with 50 µm Al₂O₃ (AA). Each group was subdivided for SEM observation and surface roughness (Ra) measurement. For SBS testing, 72 additional samples received the same surface treatments and were further subdivided according to the adhesive system: Transbond™ XT Primer (TXT) or Single Bond Universal (SBU). Results: The AA group showed the highest Ra (2.21 ± 0.30 µm), followed by HFA (0.81 ± 0.20 µm) and control (0.07 ± 0.30 µm) (p < 0.001). The highest SBS was observed in the AA + SBU group, followed by AA + TXT. Conclusions: Sandblasting with Al₂O₃ particles, combined with a universal adhesive, significantly improved bond strength, suggesting a viable protocol for 3D printed definitive composites in aligner attachment applications. Full article

Background/Objectives: The introduction of composite attachments has greatly improved orthodontic aligner therapy, through better force delivery, more predictable movements, and enhanced retention. This in vitro study aims to present and investigate an innovative digital protocol for aligner attachment fabrication incorporating the latest 3D technology used in dentistry. Methods: A virtual attachment measuring 2.5 × 2 × 2 mm was designed using computer-aided design (CAD) software (Meshmixer, Autodesk Inc., San Francisco, CA, USA) and exported as an individual STL file. The attachments were fabricated using a digital light processing (DLP) 3D printer (model: Elegoo 4 DLP, Shenzhen, China) and a dental-grade biocompatible resin. A custom 3D-printed placement guide was used to ensure precise positioning of the attachments on the printed maxillary dental models. A flowable resin was applied to secure the attachments in place. Following attachment placement, the models were scanned using a laboratory desktop scanner (Optical 3D Smart Big, Open Technologies, Milano, Italy) and three intraoral scanners: iTero Element (Align Technology, Tempe, AZ, USA), Aoral 2, and Aoral 3 (Shining 3D, Hangzhou, China). Results: Upon comparison, the scans revealed that the iTero Element exhibited the highest precision, particularly in the attachment, with an RMSE of 0.022 mm and 95.04% of measurements falling within a ±100 µm tolerance. The Aoral 2 scanner showed greater variability, with the highest RMSE (0.041 mm) in the incisor area and wider deviation margins. Despite this, all scanners produced results within clinically acceptable limits. Conclusions: In the future, custom attachments made by 3D printing could be a valid alternative to the traditional composite attachments when it comes to improving aligner attachment production. While these preliminary findings support the potential applicability of such workflows, further in vivo research is necessary to confirm clinical usability. Full article

Three-dimensional (3D) printing has emerged as a transformative technology in dental splint fabrication, offering significant advancements in customization, production speed, material efficiency, and patient comfort. This comprehensive review synthesizes the current literature on the clinical use, benefits, limitations, and future directions of 3D-printed dental splints across various disciplines, including prosthodontics, orthodontics, oral surgery, and restorative dentistry. Key 3D printing technologies such as stereolithography (SLA), digital light processing (DLP), and material jetting are discussed, along with the properties of contemporary photopolymer resins used in splint fabrication. Evidence indicates that while 3D-printed splints generally meet ISO standards for flexural strength and wear resistance, their mechanical properties are often 15–30% lower than those of heat-cured PMMA in head-to-head tests (flexural strength range 50–100 MPa vs. PMMA 100–130 MPa), and study-to-study variability is high. Some reports even show significantly reduced hardness and fatigue resistance in certain resins, underscoring material-specific heterogeneity. Clinical applications reviewed include occlusal stabilization for bruxism and temporomandibular disorders, surgical wafers for orthognathic procedures, orthodontic retainers, and endodontic guides. While current limitations include material aging, post-processing complexity, and variability in long-term outcomes, ongoing innovations—such as flexible resins, multi-material printing, and AI-driven design—hold promise for broader adoption. The review concludes with evidence-based clinical recommendations and identifies critical research gaps, particularly regarding long-term durability, pediatric applications, and quality control standards. This review supports the growing role of 3D printing as an efficient and versatile tool for delivering high-quality splint therapy in modern dental practice. Full article

Background/Objectives: This systematic review analyzed the epidemiologic and macro/microscopic features of manifestations of hypersensitivity reactions with oral and extra-oral involvement in orthodontic patients with fixed (FAs) or removable (RAs) appliances or clear aligners (CAs), and evaluated them based on patient and treatment characteristics to provide clinical recommendations. Methods: The study protocol followed the PRISMA guidelines and was registered on PROSPERO (CRD42024517942). Results: Thirty-one studies were qualitatively assessed and synthetized, involving 858 subjects (114 males and 714 females, 9–49 years old), of whom there were 86 with a history of allergy, and 743 wearing recorded appliances (FAs = 656, FAs and RAs = 81, intra- and extra-oral RAs = 3, CAs = 3), with a mean treatment duration of 21.5 months (6 weeks–40 months). Among 75 reports, 29 (38.67%), describing burning, gingival hyperplasia, erythema, and vesicles, had oral involvement, while 46 (61.33%) had skin, eye, and systemic involvement, with erythema, papules, conjunctival hyperemia, and vertigo. Positive allergy tests concomitant with the manifestations identified nickel 451 times, cobalt 6 times, titanium 5 times, and chromium 4 times. Management included antihistamines or corticosteroids and removing the offending materials, with treatment discontinuation/appliance substitution. Conclusions: Pre-treatment evaluations, including patient histories and allergy testing, are essential to identify potential allergens and select hypoallergenic materials like titanium or ceramic brackets; regular monitoring and early intervention during treatment are crucial to prevent severe outcomes. Full article

The rapid maxillary expander is one of the most widely used devices in orthodontics, and this study analyzes the skeletal and dental effects of a two-band rapid maxillary expander (RME) and a splint resin palatal expander (SRPE) in growing children with skeletal maxillary contraction. Seventy-four subjects with palatal skeletal contraction and unilateral or bilateral posterior crossbite were treated using maxillary expander devices. The sample was made up of two different randomly assigned groups: RME (21 females, 17 males; mean age ± SD 7.7 ± 1.1 years) and SRPE (24 females, 15 males; mean age ± SD 7.6 ± 1.0 years). The effects of these two different devices were evaluated based on lateral cephalograms and measurements of digital models before and after treatment (7.0 ± 1.0 months). Longitudinal changes in the different groups were evaluated statistically using Student’s t-test (p < 0.05). No significant differences in treatment effects were found for any vertical or sagittal skeletal variables in the groups. However, there was a significantly increased maxillary intercanine distance in the SRPE group (36 patients; mean ± SD = 6.0 ± 4.8 mm) compared to the RME group (38 patients; mean ± SD = 3.1 ± 2.9 mm). The results of this study showed an increase in vertical skeletal dimensions in more patients treated using SRPE than RME. Moreover, the SRPE device was shown to be better at increasing the intercanine distance, and it could therefore be preferred in children with anterior dental crowding. An evaluation of long-term treatment stability would be useful to confirm the study results. Full article

Objective: To evaluate the cytotoxicity and endocrine-disrupting potential of materials used in removable orthodontic retainers. Methods: A literature search (2015–2025) covered in vitro cytotoxicity, estrogenicity, in vivo tissue responses, and clinical biomarkers in PMMA plates, thermoplastic foils, 3D-printed resins, PEEK, and fiber-reinforced composites. Results: Thirty-eight in vitro and ten clinical studies met inclusion criteria, identified via a structured literature search of electronic databases (2015–2025). Photopolymer resins demonstrated the highest cytotoxicity, whereas thermoplastics and PMMA exhibited predominantly mild effects, which diminished further following 24 h water storage. Bisphenol-type compound release was reported, but systemic exposure remained below regulatory limits. No statistically significant mucosal alterations or endocrine-related effects were reported in clinical studies. Conclusions: Retainer materials are generally biocompatible, though data on long-term endocrine effects are limited. Standardized biocompatibility assessment protocols are necessary to enable comparative evaluation across diverse orthodontic materials. Single-use thermoplastics contribute to microplastic release and pose end-of-life management challenges, raising concerns regarding environmental sustainability. Full article

White spot lesions (WSLs) are early clinical stages of enamel demineralization, often related to orthodontic treatment or poor oral hygiene. The use of gels such as fluoride for topical application inhibits demineralization and promotes remineralization of dental tissues through various mechanisms. A variety of therapeutic approaches are available; however, recent research indicates that combined treatment strategies may yield superior clinical outcomes compared to monotherapy. The aim of this study was to critically compare the efficacy of combining multiple treatment techniques for WSLs compared to using these techniques alone. A systematic search was conducted in PubMed, Scopus, and Cochrane databases according to PRISMA guidelines. The PICO strategy was used to formulate the research question: Which clinical approaches combined or isolated (C) influence the treatment and prevention effectiveness (O) of white spot lesions (I) in humans (P) in the last ten years (T)? Inclusion criteria focused on clinical studies from the last ten years evaluating the combined use of at least two treatment techniques for WSL, resulting in a total of 8 randomized controlled trials selected from an initial pool of 1185 articles. Our results suggest that combined treatment strategies, including resin infiltration with fluoride varnish and ozone therapy combined with fluoride application, demonstrated enhanced efficacy in lesion masking and remineralization compared to single-treatment approaches. CPP-ACP and hydroxyapatite-based creams improved aesthetics, particularly when used alongside fluoride varnish. Our study concluded that the combination of remineralization agents like fluoride gel, infiltrative resins, and antimicrobial treatments offers superior outcomes on white spot lesion treatment than using these techniques alone. However, long-term clinical studies are needed to standardize treatment protocols and confirm durability. Full article

Silver nanoparticles (AgNPs) have emerged as a promising antimicrobial agent in dentistry due to their distinctive physicochemical characteristics and broad-spectrum biocidal activity. For example, silver nanoparticles can be incorporated into oral hygiene products in preventive dentistry, composite resins in restorative treatment, irrigation solutions in endodontic treatment, membranes for guided tissue regeneration in periodontal treatment, acrylic resins and porcelains in prosthodontic treatment, coatings in dental implant treatment, and brackets and wires in orthodontic treatment. This paper focuses on summarizing the current knowledge on the antimicrobial use of silver nanoparticles in dentistry, highlighting their antimicrobial mechanism and potential applications in clinical treatment. The literature indicates that silver nanoparticles are a promising antimicrobial agent in dentistry. However, there are still many issues including fundamental antibacterial mechanisms that need to be completely elucidated before clinical applications. Full article

Objectives: Trauma to maxillary incisors is frequent, and requires timely, conservative management for optimal prognosis. This in vitro study evaluated the fracture resistance (FR) and orthodontic bracket bond strength (BS) of incisors following incisal fragment reattachment using various restorative techniques. Materials and Methods: Two independent tests—FR testing (Newtons) and BS testing (megapascals)—were conducted. Eighty intact human maxillary central incisors (n = 40/test), standardized in size and shape using a digital caliper (Mitutoyo, ±0.01 mm), were embedded in acrylic resin and numbered. An uncomplicated crown fracture was induced in 64 teeth (n = 32/test), and the teeth were randomly assigned (simple randomization using Excel’s RAND function) to five groups (n = 8/group/test): (1) intact teeth (negative control, NC); (2) nanohybrid composite buildup using Filtek Z250 and Single Bond 2 (positive control, CB); (3) fragment reattachment using flowable composite (Filtek Supreme, FL); (4) reattachment with a palatal veneer using a nanohybrid composite (PV); and (5) reattachment reinforced with a polyethylene fiber band (Ribbond Inc., RB). In BS testing groups, stainless steel orthodontic brackets (PINNACLE) were bonded using Transbond XT, centered over the fracture line. Light curing was performed using an LED unit (Mini LED Standard, Acteon, 1250 mW/cm², 20 s/bond, 40 s/composite, 2 mm curing tip distance). Specimens were stored in distilled water at room temperature for 24 h before reattachment. FR and BS were evaluated using a universal testing machine (Instron) until failure. Failure modes were analyzed, and data were statistically evaluated using one-way ANOVA, Tukey’s post hoc test, and Pearson’s correlation analysis. Results: Significant differences were observed among groups for both FR and BS (p < 0.05). The NC group exhibited the highest FR (514.4 N) and BS (17.6 MPa). The RB group recorded the second-highest FR (324.6), followed by the PV (234.6), CB (224.9), and FL (203.7) groups. The CB group demonstrated the second-best BS (16.6), followed by the RB (15.2), FL (13.4), and PV (6.5) groups. FR and BS were negatively correlated. Mixed failures predominated in the reattachment groups, except for the PV group, which showed mainly adhesive failures. In BS testing, mixed failures dominated in the NC and CB groups, while adhesive failures predominated in the PV and FL groups. Conclusions: Ribbond reinforcement improves the mechanical performance of reattached incisal fragments, and composite buildup may provide more reliable bracket bonding than fragment reattachment. Clinical Relevance: In cases where biomimetic, minimally invasive reattachment is indicated, Ribbond fiber reinforcement appears to offer a reliable restorative solution. Full article

Background/Objectives: This study evaluated the trueness and precision of three low-cost 3D printers compared to a professional-grade printer in fabricating orthodontic models. Methods: Two upper dental models, one crowded and one non-crowded, were designed using Blenderfordental and Autolign. The models were printed with Anycubic M3 Premium, Anycubic Photon D2, Phrozen Sonic Mini 8K, and Ackuretta Sol at 45° and 90° using Elegoo orthodontic and Ackuretta Curo resins. A total of 384 models were produced: 256 crowded (128 at 90° and 128 at 45°) and 128 non-crowded (all at 45°). Chitubox Dental Slicer and ALPHA AI slicer were used for slicing. Post-processing involved cleaning with Ackuretta Cleani and curing in Ackuretta Curie. The models were scanned with Smartoptics Vinyl Open Air. Trueness was assessed using RMS deviation analysis in CloudCompare and linear measurements. Results: One-way ANOVA showed significant differences in trueness among the printers at 45° (p < 0.001) and 90° (p < 0.001). The Ackuretta Sol (LCD) exhibited the highest trueness, with the lowest mean RMS values at 45° (0.095 ± 0.008 mm) and 90° (0.115 ± 0.010 mm). The Anycubic M3 Premium (LCD) had the lowest trueness, with RMS values at 45° (0.136 ± 0.015 mm) and 90° (0.149 ± 0.012 mm). The 45° build angle resulted in significantly better trueness than 90° (p < 0.001). In linear measurements, deviations exceeding 0.25 mm were observed only in the R1 distance, except for the Ackuretta SOL, which remained below this threshold. Conclusions: The professional-grade printer demonstrated the best performance overall. Printing at a 45° build angle resulted in improved accuracy. Despite differences among devices, all printers produced results within clinically acceptable limits for orthodontic use. Full article

Patient demands for aesthetic orthodontic brackets (OBs) has increased since orthodontic treatments are of long duration. Clinicians encounter old composite restorations frequently, against which OBs need to be bonded. This study aims to determine the shear bond strength (SBS) of two aesthetic OBs (ceramic and resin) against aged composite resins (flowable and packable) after standard surface treatment. A total of 96 disk-shaped specimens of two aged (A) composite resins [flowable (F) and packable (P)] were divided into eight groups, using ceramic (C) and plastic (P) brackets, out of which four subgroups served as the control [non-aged (N)FC, NPC, NFR, NPR] and four as experimental [AFC, APC, AFR, APR]. Surface treatment included mechanical [air abrasion] and chemical [Assure Plus and Transbond XT]. After 24 h of storage, the specimens were tested for SBS and observed for failure mode using adhesive remnant index scores. Mean values of SBS in each subgroup were analyzed statistically using a one-way analysis of variance test and Tukey post hoc test. All probability ‘p’ differences were significant at a value of 0.05 and less. All aged composite resin subgroups had decreased bond strength than controls, with all subgroups bonded with plastic brackets having the least bond strengths that were clinically nonacceptable [≤7 to 10 MPa]. Flowable composites when bonded with either ceramic or plastic brackets had higher strength than packable composites. Ceramic brackets had higher SBS than plastic brackets for both flowable and packable composites. Significant differences in bond strength were observed among subgroups of plastic brackets. Ceramic brackets were associated with a higher residue of adhesives on the composite surface. Aged composite resins exhibit significantly lower SBS than fresh composites, with ceramic brackets and flowable composites producing better bond strength values than plastic brackets and packable composites. Full article

This study aims to assess and compare the shrinkage, accuracy, and accuracy stability of a novel 3D-printing model resin and eight commercially available 3D-printing model resin materials. The experimental model resin was developed by our 3D-printing proprietary resin technology. Eight commercially available 3D-printing model resins were included for comparison. The AcuVol video imaging technique was used to test volumetric shrinkage. Full-arch tooth models were printed for each model resin via digital light processing (DLP) technology. The 3D average distance between the scanned model and the designed CAD digital file was applied to determine the dimensional accuracy of the 3D-printed full-arch tooth models. One-way ANOVA and Tukey’s post hoc test (p < 0.05) were utilized to analyze the average values of volumetric shrinkage and 3D average distance (dimensional accuracy). The experimental model resin showed significantly lower volumetric shrinkage (7.28%) and significantly higher or higher accuracy and accuracy stability (11.66–13.77 µm from the initial day to four weeks) than the other commercially available model resins (7.66–11.2%, 14.03–41.14 µm from the initial day to four weeks). A strong correlation was observed between volumetric shrinkage and dimensional accuracy (Pearson correlation coefficient R = 0.7485). For clinically successful modelling applications in restorations, orthodontics, implants, and so on, the new 3D-printing model resin is a promising option. Full article