Search Results (85)

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

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

Pediatric dentistry continually seeks effective and efficient treatments for young patients, especially within pediatric endodontics, where cooperation can often be challenging. This in vivo study aimed to evaluate the effectiveness of a novel photodynamic therapy (PDT) protocol using a 5-aminolevulinic acid gel (Aladent, ALAD) combined with light irradiation during the endodontic treatment of primary teeth. This study included primary teeth requiring root canal therapy due to carious lesions or trauma, with clinical symptoms suggesting irreversible pulpitis or acute apical periodontitis. Following local anesthesia and isolation with a rubber dam, carious lesions were excavated, and access to the pulp chamber was established. Canal preparation included determining the working length and using a sequence of k-files. Afterward, ALAD gel was applied, and the patients were divided into two groups based on their visit duration (Group A with a single visit, Group B returning after one week). Microbiological analysis was conducted on the samples taken before and after treatment. The findings demonstrated significant antibacterial efficacy of the PDT protocol in reducing root canal bacterial load, suggesting ALAD-based PDT may serve as an alternative to traditional endodontic treatment in cases where retaining primary teeth is essential for orthodontic or strategic reasons. Clinically, improvement in symptoms and fistula resolution were observed. Treatment time, patient compliance, and protocol safety in pediatric applications are also discussed, highlighting the protocol’s potential to enhance clinical outcomes in pediatric endodontics. Full article

Background and Objectives: Halitosis is a persistent oral health issue that can undermine self-esteem and social interactions, particularly in younger populations who may be more vulnerable to peer judgment. Orthodontic retainers—both removable and fixed—can alter oral microbiota and salivary parameters, potentially influencing malodor development. This study aimed to compare halitosis severity and oral-health-related quality of life (OHRQoL) in adolescents and young adults (aged 12–25) wearing removable retainers, fixed retainers, or no orthodontic appliances, with an additional focus on salivary pH as a possible modifying factor. Methods: A total of 88 participants were allocated into three groups: removable retainer (n = 28), fixed retainer (n = 30), and no orthodontic treatment (n = 30). Halitosis severity was measured via organoleptic evaluation (0–5 scale) and the Halitosis Associated Life-Quality Test (HALT, 0–100). Salivary pH was determined using a digital pH meter. OHRQoL was assessed through the Oral Health Impact Profile–14 (OHIP-14, 0–56). One-way ANOVA with Tukey’s post hoc test and chi-square analyses were employed to compare outcomes among groups. Spearman’s correlation explored relationships among HALT, organoleptic scores, OHIP-14, and salivary pH. Results: Fixed retainer wearers exhibited higher mean organoleptic scores (2.2 ± 0.6) compared to removable retainer users (1.7 ± 0.5, p = 0.003). HALT results similarly showed that the fixed retainer group (35.6 ± 6.4) reported more halitosis-related burdens than the removable group (31.4 ± 5.9, p = 0.015). Low salivary pH (<6.8) was linked to greater malodor indices in all cohorts (p < 0.05). Correlations revealed moderate positive associations between HALT and OHIP-14 (r = +0.52, p < 0.001). Conclusions: Adolescents and young adults wearing fixed orthodontic retainers reported more severe halitosis and a correspondingly lower oral-health-related quality of life than those with removable retainers or no orthodontic appliances. Salivary pH emerged as an influential factor, indicating that maintaining a neutral oral environment could mitigate malodor. Targeted interventions emphasizing hygiene and saliva management may improve overall well-being in this vulnerable age group. Full article

Compromised first permanent molars (FPMs) in children pose major challenges for dentists and patients even in low-caries-risk populations. Whether due to caries or Molar Incisor Hypomineralization (MIH), compromised FPMs at an early age require careful treatment planning and timing of extraction, if necessary, to eventually have good space closure with healthy dentition. This comprehensive review explains the concept of early extraction of the FPMs in children and lists the results of published studies and systematic reviews regarding spontaneous or orthodontical space closure after the extraction of an FPM, including its consequences in the long term. In general, the majority of the studies confirm that spontaneous space closure after the early extraction of the maxillary FPM could be achieved if the extraction is performed before the eruption of the second permanent molar (SPM). On the other hand, space closure in the mandible is possible in case of optimal timing of extraction and supporting co-factors, but in practice, it would most probably require orthodontic treatment. The decision to retain or extract compromised FPMs must always be made on an individual basis, taking into account all relevant factors and the long-term effects on the entire stomatognathic system. Early prophylaxis to prevent caries and early management of MIH-affected FPMs should, however, be the first-line approach. Full article

Background: The prevalence of gingival recessions (GRs) in the global population is 78%. A long-term study showed a 47% increase in the prevalence of GRs five years post-orthodontic treatment, particularly in the lower anterior region. It can be caused and/or exacerbated after orthodontic treatment, where the retainer placed can induce tooth movement or when it fails to maintain a passive position upon bonding. Thus, the goal of this case report was to present treatments for gingival recessions, with the approaches of the laterally closed tunnel technique and parallel incision methods, after orthodontic treatment in patients using non-passive lingual retainers. Methods: This case report adhered to the CARE guidelines. Three healthy patients were referred due to GR defects in the lower anterior region (RT1 and RT2). All patients had GR associated with deficient lingual-fixed orthodontics retainers. The same experienced periodontist (ATD) developed the surgeries and aimed to achieve root coverage using the connective tissue graft associated with a coronally advanced flap (CAF) and modify the recipient area’s gingival phenotype. Results: In all cases, a new orthodontic treatment was not possible due to anatomical or patient-related factors. Outcomes after six months, three years, and five years are presented, encompassing clinical and esthetic evaluations. Conclusions: GRs must always be addressed by orthodontic therapy or lingual-fixed orthodontic retainers. In cases where dental elements are positioned outside the bone envelope, orthodontic treatment may be considered before root coverage surgery. Therefore, surgical intervention should be undertaken for the keratinized tissue and volume gain, independently of the tooth position. Modifying the phenotype in these situations is vital for the long-term maintenance of periodontal health. Full article

Objectives: The objectives of this study were to investigate in vitro BPA release from two common fiberglass fixed lingual canine-to-canine retainers and to compare these amounts with those released from a conventional multistranded stainless-steel orthodontic retainer. Methods: Fifty-four recently extracted teeth were divided into groups of six teeth each, formed in an arch shape. Three different retainer types were evaluated: Ribbond, EverStick Ortho and Wildcut wire. Three identical specimens were constructed for each retainer type. BPA release was determined with validated the liquid chromatography–tandem mass spectrometry method at 1 and 24 h, as well as at 7, 14 and 30 days. The method’s limits of detection and quantification were 0.32 ng/mL and 0.96 ng/mL, respectively. A two-way mixed, repeated-measures analysis of variance with Greenhouse–Geisser correction was employed to verify the existence of any significant differences. Results: Higher levels of BPA were released from the polyethylene fiber and glass fiber retainer in comparison with the conventional retainer in the present study. The differences between the systems over time were not statistically significant at the 95% confidence level. Conclusions: In vitro BPA release during the first month did not differ between the examined retainer types. The highest BPA concentrations were observed at 1 month. Full article

Background/Objectives: The injection moulding technique (IMT) is a minimally invasive restorative treatment. This technique enables the application of thin, flowable composite layers into a stable, transparent silicone index that serves as a mould. Due to the fluid properties of the composite, it efficiently fills the silicone tray and seamlessly integrates with the tooth structure, often obviating tooth preparation and preserving overall tooth integrity. The procedure employs the etch-and-rinse protocol and is highly reproducible. Minimally invasive restorative techniques are particularly relevant following orthodontic treatment, where minor tooth adjustments are often required to achieve optimal aesthetics and function. Integrating orthodontic and restorative treatments is pivotal for long-term success, especially in complex interdisciplinary cases. Methods: This retrospective study describes the application of conservative restoration using the IMT in two pediatric patients (12.6 years old and 12.3 years old) to restore maxillary lateral incisors before and after orthodontic treatment. The technique provides a viable option for temporary composite restorations until the patients are suitable candidates for permanent all-ceramic veneers. Results: The injectable technique is ideal for minimal diastemas, small interdental spaces, or retruded teeth. The cases presented, involving irregular tooth sizes and morphologies, demonstrate the suitability of the IMT in scenarios requiring an additive approach. This technique effectively addresses such irregularities without necessitating invasive preparation. Conclusions: The IMT is a valuable tool for pediatric patients undergoing orthodontic treatment, both at its initiation and completion. The technique assists orthodontists in finalising treatment by addressing Bolton index discrepancies and correcting tooth shape anomalies. Additionally, a digital workflow reduces clinical sessions, as thermo-printed retainers can be delivered during the same appointment as the IMT, providing economic and organisational benefits. This approach underscores the utility of the IMT in enhancing treatment efficiency and outcomes in orthodontic–restorative care. Full article

Clear aligners have transformed orthodontic care by providing an aesthetic, removable alternative to traditional braces. However, their significant environmental footprint, contributing to approximately 15,000 tons of plastic waste annually, poses a critical challenge. To address this issue, advancements in 4D printing have introduced “smart” aligners with shape memory properties, enabling reshaping and reducing the number of aligners required per treatment. This study focuses on ClearX aligners, an innovative 4D-printed solution aimed at extending usage duration and minimizing environmental impact. Using a comprehensive suite of tests, including morphological, optical, and mechanical evaluations conducted via scanning electron microscopy, UV-Vis spectroscopy, infrared spectroscopy, and bending and strain assessments, we evaluated the optical and mechanical stability of the ClearX material before and after thermal activation. Our results demonstrate that ClearX aligners retain their structural and functional properties after reshaping. Temporary changes in transparency, observed only under prolonged treatment durations exceeding manufacturer recommendations, are fully reversible within 12 h and do not compromise the aligner’s usability. These findings support the potential of ClearX aligners to effectively combine patient-centered, high-quality orthodontic care with sustainable practices. Full article

(1) Background: After more than a decade since their first description, Inadvertent Tooth Movements (ITMs) remain an adverse effect of orthodontic retainers without a clear etiology. To further investigate the link between ITMs and the mechanical properties of different retainers, the response upon vertical loading was compared in three retainer types (two stainless steel and one nickel–titanium). The influence of different reference teeth was also considered. (2) Methods: Three retainers (R1, R2, R3) were tested in a newly developed biomechanical analysis system (FRANS). They were bonded to 3D-printed models of the lower anterior jaw and vertically displaced up to 0.3 mm. Developing forces and moments were recorded at the center of force. (3) Results: The vertical displacement caused vertical forces (Fz) and labiolingual moments (My) to arise. These were highest in the lateral incisors (up to 2.35 ± 0.59 N and 9.27 ± 5.86 Nmm for R1; 1.69 ± 1.06 N and 7.42 ± 2.65 Nmm for R2; 3.28 ± 1.73 N and 15.91 ± 9.71 Nmm for R3) for all analyzed retainers and with the R3 retainer for all analyzed reference teeth, while the lowest Fz and My values were recorded with the R1 retainer. (4) Conclusions: Displacements of 0.2 mm and larger provided forces and moments which could be sufficient to cause unwanted torque movements, such as ITMs, in all analyzed retainers. Clinicians must be mindful of these risks and perform post-treatment checkups on patients with retainers of all materials. Full article

Background: The need to perform occasional or continuous MRI exams and the interference with metal orthodontic appliances might be important and take a primary role during retention since the retention period is significantly longer than orthodontic treatment. Several non-metallic materials were proposed as potential alternatives to perform fixed retainers in orthodontics, but they showed internal limits. Methods: Polyetheretherketone (PEEK) was used in the present clinical report as a fixed orthodontic retainer in the lower arch in order to perform an appliance with mechanical properties comparable to metallic ones but with a higher biocompatibility material and without the need for removal in case of an MRI exam. The retainer wire was handmade in the studio and then shaped to fit the arch. Results: PEEK showed a good capability for constructing a lingual fixed retainer compared to other aesthetic non-metallic and metallic materials. Conclusions: To the best of our knowledge, this study proposes how to easily build a retainer in PEEK and provides a clinical example of how this material can be beneficial. Full article

Objectives: Orthodontists are often asked to remove fixed retainers before patients undergo magnetic resonance imaging (MRI). The present in vitro study was designed to analyze the heating and bonding efficacy of stainless steel multibraided fixed retainers after 1.5- and 3-tesla (T) MRI. Materials and methods: A total of 180 human mandibular incisors were used to create 45 specimens of four teeth each, divided into nine groups. Handmade multibraided fixed retainers of three different sizes, defined by the diameter of the initial wire used (0.008″, 0.010″ and 0.012″), were tested. Three groups underwent MRI at 1.5 T, another three groups underwent MRI at 3 T and the last three groups did not undergo MRI. Temperature was assessed before and after MRI. Shear bond strength (SBS) and adhesive remnant index (ARI) were assessed after MRI for all groups. Data were statistically analyzed (p < 0.05). Results: After 1.5 T exposure, no significant temperature increase from T0 to T1 was observed in any of the groups (p > 0.05). Regarding the 3 T groups, a significant difference from T0 to T1 was found for all the groups (p < 0.05). Temperature changes were not clinically relevant, as they were less than 1 °C for all groups except for group 3 (ΔT0–T1: 1.18 ± 0.3 °C) and group 6 (ΔT0–T1: 1.12 ± 0.37 °C). Furthermore, there were no significant differences between the temperature variations associated with different wire diameters (p > 0.05). Conclusions: No significant changes in SBS or ARI were found (p > 0.05). Clinical significance: Since overheating was irrelevant and adhesion values did not change, the tested devices were concluded to be safe for MRI examinations at 1.5 T and 3 T. Full article

This case report presents a virtual treatment simulation of the orthodontic treatment and surgery-first orthognathic surgery employed to treat a patient with a repaired unilateral cleft lip and alveolus with Class III malocclusion and lower third facial asymmetry. The patient exhibited a negative overjet of 9 mm, a missing lower right second premolar, and a 5 mm gap between the upper right central and lateral incisors with midline discrepancy. The three-dimensional virtual planning began with virtual pre-surgical orthodontics, followed by the positioning of the facial bones and teeth in their ideal aesthetic and functional positions. The sequence of steps needed to achieve this outcome was then reverse-engineered and recorded using multiplatform Nemostudio software (Nemotec, Madrid, Spain), which facilitated both surgical and orthodontic planning. The treatment included a two-piece segmental maxillary osteotomy for dental space closure, a LeFort I maxillary advancement, and a mandibular setback with bilateral sagittal split osteotomy to correct the skeletal underbite and asymmetry. A novel approach was employed by pre-treating the patient for orthognathic surgeries at age 11, seven years prior to the surgery. This early phase of orthodontic treatment aligned the patient’s teeth and established the dental arch form. The positions of the teeth were maintained with retainers, eliminating the need for pre-surgical orthodontics later. This early phase of treatment significantly reduced the treatment time. The use of software to predict all the necessary steps for surgery and post-surgical orthodontic tooth movements made this approach possible. Multi-step virtual planning can be a powerful tool for analyzing complex craniofacial problems that require multidisciplinary care, such as cleft lip and/or palate. Full article

This study aimed to assess the key physico-mechanical properties and bonding performance of orthodontic adhesives with graphene addition for bonding a fixed retainer. Transbond LR (3M) and Transbond LV (3M) with no graphene were set as the control groups. Graphene was added into LR and LV at concentrations of 0.01 wt%, 0.05 wt% and 0.1 wt%. The stickiness of the uncured samples (n = 5) and real-time degree of conversion (DC) of the samples (n = 3) were measured over a 24-h period using Fourier-transform infrared spectroscopy. The hardness and other mechanical parameters, including the Martens hardness (HM), indentation modulus (E_IT), elastic index (η_IT) and creep (C_IT), were measured (n = 5). To measure the shear bond strength (SBS), adhesive composites were applied using a mold to bond the retainer wire to the lingual surfaces of bovine incisors (n = 10). Fracture modes subsequent to the SBS test were examined under light microscopy. Statistical analysis was conducted using ANOVA and Tukey tests (α = 0.05). In the LR groups, the LR + 0.01 showed the highest SBS (12.6 ± 2.0 MPa) and HM (539.4 ± 17.9 N/mm²), while the LV + 0.05 (7.7 ± 1.1 MPa) had the highest SBS and the LV + 0.1 had the highest HM (312.4 ± 17.8 N/mm²) among the LV groups. The most frequent failure mode observed was adhesive fracture followed by mixed fracture. No statistical difference was found between the graphene-added groups and the control groups in terms of the E_IT, η_IT and C_IT, except that the C_IT was significantly lower in the LR + 0.01 than in the control group. Graphene addition had no significant adverse effect on the stickiness and DC of both LR and LV. Full article

This study presents a scanning electron microscopy analysis of a failed PEEK retainer in an orthodontic patient. After 15 months of use, the patient reported a gap opening between teeth 41 and 42. The PEEK retainer was removed and sent for electron microscope analysis. To investigate the failure, scanning electron microscopy was employed to assess the microstructure and composition of the retainer at various magnifications. These findings suggest that the failure of the PEEK retainer was multifaceted, implicating factors such as material defects, manufacturing flaws, inadequate design, environmental factors, and patient-related factors. In conclusion, this scanning electron microscopy analysis offers valuable insights into the failure mechanisms of PEEK retainers in orthodontic applications. Further research is necessary to explore preventive strategies and optimize the design and fabrication of PEEK retainers, minimizing the occurrence of failures in orthodontic practice. Full article