Search Results (131)

Background: The fabrication of orthodontic aligners directly via three-dimensional (3D) printing presents potential to increase the efficiency of aligner production relative to traditional workflows; however, several aspects of the 3D printing process might affect the dimensional fidelity of the fabricated appliances. The aim of this study is to measure the forces expressed by a 3D printed aligner made with TC-85 DAC resin (Grapy Inc., Seoul, Republic of Korea) when an expansion movement of the entire upper dental arch is programmed, comparing the measured forces with those obtained by a common thermoformed aligner (Smart Track^®, Align Technology, Santa Clara, CA, USA). Materials and methods: A patient in transitional mixed dentition was selected, with the presence of all the first molars and permanent upper and lower incisors, and the canines and premolars have not started the exchange. From this patient, a virtual set up of the upper arch has been planned with an expansion of 0.2 mm and 0.4 mm per side; 3 mm horizontal rectangular attachments were added to the set up on the vestibular surface of the permanent molars, deciduous premolars, and deciduous canines. On this set up, 10 Smart Track aligners and 10 3D printed aligners with TC-85 DAC resin were produced. The fabricated aligners were mounted on the machinery used for the test (ElectroForce^® Test Bench; TA Instruments, New Castle, DE, USA) by means of specific supports that simulate the upper arch of the patient (divided into two sides: right and left). To simulate the intraoral environment, the measurements were carried out in a thermostatic bath at a temperature of 37 °C. Results: The key results of this paper showed differences between Smart Track^® and TC-85 DAC. In particular, the expanding force exerted by the 0.2 mm per side expanded Smart Track^® aligners was on average +0.2162 N with a D.S. of ±0.0051 N during the 8 h; meanwhile, the force exerted by the 0.2 mm per side expanded TC-85 DAC 3D printed aligners was on average −0.0034 N with a D.S. of ±0.0036 N during the 8 h. The force exerted by the 0.4 mm per side expanded Smart Track^® aligners was on average +0.7159 N with a D.S. of ±0.0543 N during the 8 h; meanwhile, the force exerted by the 0.4 mm per side expanded TC-85 DAC 3D printed aligners was on average +0.0141 N with a D.S. of ±0.004 N during the 8 h. Conclusions: Smart Track^® aligners express a quantitatively measurable force in Newtons during the programmed movements to obtain a posterior expansion of the dental arches; on the contrary, aligners made with TC-85 DAC resin, in light of the results obtained from this study, express forces close to 0 during the realization of the movements programmed to obtain a posterior expansion of the dental arches. Full article

Background: Reduced bond strengths in hypmineralised enamel have been reported with increased restorative failures. This study aimed to investigate the shear bond strengths of resin composite to hypomineralised enamel and dentin bonded with two different adhesive systems and pre-treatments. Methods: Thirty-six freshly extracted first permanent molars with MIH and 17 sound third molars were used for shear bond strength tests in enamel and dentin. Specimens of control groups were bonded to resin composite using Scotchbond^TM Universal Plus and Adper^TM Scotchbond 1XT. MIH-affected enamel specimens of six test groups were pre-treated with various chemical agents, such as 35% phosphoric acid, 5% NaOCl, resin infiltration with ICON^®, or a combination of these agents prior to bonding with composite resin using Scotchbond^TM Universal Plus. Bonded specimens were subsequently sheared at a crosshead speed of 1.0 mm/min, after which their fracture modes were recorded. The mean bond strengths of all groups were compared using a one-way analysis of variance test (ANOVA) and a Bonferroni–Holm analysis was performed for pairwise comparison between the groups. The association between modes of failure was examined with Pearson’s chi-square test. Results: Mean shear bond strength values were highest for sound dentin specimens (Group SD 2) bonded with Scotchbond^TM Universal Plus (23.76 ± 7.68 MPa). Sound enamel specimens (Group SE 2) exhibited significantly higher mean bond strength values than MIH-enamel specimens (Group HE 2) when bonded with Scotchbond^TM Universal Plus (19.68 ± 6.25 vs. 11.53 ± 3.29 MPa, p < 0.001). Oxidative pre-treatment followed by resin infiltration significantly improved bond strengths to hypomineralised enamel (Group HE 6) (17.84 ± 2.98 MPa, p < 0.05). Bond strengths to sound and hypomineralised enamel and dentin did not differ significantly for both adhesives. Conclusions: Within the limitations of an in vitro study, oxidative pre-treatment in combination with resin infiltration seems to be beneficial when planning adhesive restorations with composite in hypomineralised enamel. Both Scotchbond^TM Universal Plus and Adper^TM Scotchbond 1XT can be used for bonding of resin composite to MIH-affected enamel and dentin. Full article

Molar incisor hypomineralization (MIH) is characterized by systemic hypomineralization affecting one to four first permanent molars (FPMs), often accompanied by lesions in incisors and potentially involving other primary or permanent teeth. MIH poses clinical challenges, including hypersensitivity, susceptibility to pulp involvement, and aesthetic concerns. Optical Coherence Tomography (OCT), an advanced, non-invasive imaging modality, has gained interest as a potential diagnostic tool in dentistry. This exploratory observational case-control study aims to compare the structural characteristics of MIH-affected and healthy teeth using in vivo OCT, focusing on identifying qualitative imaging patterns associated with enamel hypomineralization. This study included 50 mild MIH-affected permanent teeth from pediatric patients and 50 healthy permanent teeth as controls. Representative OCT scans were acquired, analyzed, and compared for both groups. In OCT imaging, healthy enamel and dentin appeared as two distinct superimposed layers defined by the dentin-enamel junction. Conversely, MIH-affected teeth exhibited characteristic subsurface hyper-reflective zones, indicative of hypomineralized enamel, with deeper hypo-reflective shadowing. This first in vivo study applying OCT to MIH-affected teeth demonstrates its potential as a non-invasive technique for the real-time assessment of enamel structural anomalies, supporting its future role in monitoring remineralization therapies and improving early detection strategies in pediatric dental care. Full article

Objective: This study aimed to evaluate the mean age of eruption of permanent teeth and their clinical emergence sequence in a longitudinal sample of children from a multi-ethnic urban population. Methods: A total of 854 children (413 females and 441 males), aged between 4 and 13 years, were examined annually for a minimum of 4 consecutive years, as part of their annual dental screening appointment. The presence of permanent teeth was recorded at each examination. Mean and median ages, with standard deviations, of individual tooth eruption were calculated, in addition to the eruption sequence, and the analysis of the data was performed using the lognormal distribution model. Regarding the error of the method, two examiners reviewed all relevant dental screening forms, and any discrepancies were resolved through consultation with the senior author. Results: The sequence of permanent tooth eruption followed a consistent pattern across sexes, with distinct differences between the maxillary and mandibular arches. In the maxilla, eruption began with the first molar, while in the mandible, it started with the central incisor. Mandibular teeth generally erupted earlier than maxillary teeth, with girls experiencing earlier eruption than boys, with some exceptions, and prolonged eruption periods. No statistically significant differences were found in the timing of eruption between contralateral homologous teeth. Conclusions: Based on the present data, the observed sequence of tooth eruption in a multi-ethnic urban population showed similar patterns across sexes. Mandibular teeth generally erupt earlier than maxillary teeth, with girls experiencing earlier eruption than boys. Full article

Primary teeth play a crucial role in a child’s development, particularly in maintaining space for permanent teeth. The premature loss of a primary tooth can lead to orthodontic issues, making the use of space maintainers essential to ensure proper growth and development of permanent teeth. To preserve space, the fabrication of a space maintainer is necessary. Since conventional space maintainers do not restore masticatory function, this study presents an innovative solution for space preservation following the extraction of the first primary molar through the design of the functional space maintainer KOS&MET (Key Orthodontic System and Materials Enhanced Therapy). The space maintainer was designed using the 3Shape Dental Designer 2023 version software tool and manufactured via additive 3D printing, utilizing a metal alloy with high resistance to masticatory forces. The crown is supported by the primary canine, while an intraoral window is created to monitor the eruption of the successor tooth. This design does not interfere with occlusion and enables bilateral chewing. Masticatory performance was assessed using two-color chewing gum, and the results showed improvement after cementing the space maintainer. This innovative approach not only preserves space for permanent teeth but also enhances masticatory function, contributing to the proper growth and development of the jaws and teeth. Full article

Introduction: Dental caries and molar–incisor hypomineralisation (MIH) are prevalent conditions affecting children’s oral health, with functional, aesthetic, and psychosocial implications. In Spain, previous studies have highlighted geographic and sociodemographic disparities in their distribution, particularly among rural and migrant populations. Objective: To characterise oral health status, in terms of caries and MIH, among 6–7-year-old children from the towns of Palos de la Frontera, Mazagón, and San Bartolomé. Methods: A cross-sectional study was conducted involving 229 children recruited from public primary schools. Sociodemographic, anthropometric, and behavioural data were collected through clinical examination and interview. Statistical analysis included univariate and multivariate logistic regression. The study protocol was approved by the Ethics Committee of Huelva. Results: The prevalence of caries (DMFT ≥ 1) was 53.3%, with mean DMFT and dft indices of 1.78 and 0.31, respectively. MIH affected 32.8% of the cohort, with a predominance in the first permanent molars (teeth 36 and 26). Multivariate analysis identified independent predictors of caries: African (OR = 7.47; 95% CI: 2.84–23.8) and European (OR = 4.56; 95% CI: 1.26–22.3) parental origin, poor oral hygiene (OR = 3.07; 95% CI: 1.60–6.03), and the presence of MIH (OR = 3.20; 95% CI: 1.64–6.42). The municipality of San Bartolomé was associated with a higher risk of MIH (OR = 2.90; 95% CI: 1.21–7.45). Conclusions: The high prevalence of caries and MIH in the Condado-Campiña district, exceeding national averages, reflects oral health inequities linked to social determinants (migrant origin, locality) and clinical factors (MIH, oral hygiene). Targeted preventive interventions are urgently needed in high-risk populations, including culturally tailored education and policies ensuring equitable access to dental care services. Full article

This study aimed to assess dental caries status of 3- to 6-year-old preschool children in the Republic of Serbia. Stratified cluster sampling was implemented. Children were examined in four administrative regions of Serbia. Dental caries indices (decayed, missing, and filled) for deciduous teeth and the first permanent molar were recorded at the tooth level (dmft, DMFT) and surface level (dfs, DFS). In addition to cavitated caries lesions (ICDAS 3-6), visual changes in enamel (ICDAS 1-2) were recorded. This study included 1060 3-year-old and 1820 6-year-old children in Serbia. Fifty-six percent of 3-year-olds and 21% of 6-year-olds were caries-free. The mean dmft was 2.11 ± 3.45 for 3-year-olds and 4.46 ± 3.69 for 6-year-olds. The mean dfs was 2.62 ± 5.56 for 3-year-olds and 6.06 ± 6.33 for 6-year-olds. The decayed component was dominant in dmft/dfs. The prevalence of surfaces with initial lesion was 8% for 3-year-olds and 13% for 6-year-olds. Among children diagnosed with early childhood caries, 54% of 3-year-olds and 37% of 6-year-olds had a severe form. The mean DMFT was 0.15 ± 0.55, with only the first permanent molars being affected. Dental caries remains a significant public dental health issue among preschool children in Serbia. There is a noticeable trend of increasing numbers of decayed teeth as children progress through their preschool years. It is imperative to take corrective action enhance the existing oral health prevention program in Serbia with the aim of achieving better dental health among preschool children. Full article

Molar Incisor Hypomineralization (MIH) is a common dental condition that affects the mineralization of the enamel, primarily affecting the first permanent molars and often the incisors. This condition can lead to a wide range of clinical presentations, from mild opacities to severe post-eruptive breakdown, which can significantly impact a child’s oral health and quality of life. Background/Objectives: The prevalence and complex management of MIH have posed a significant challenge for dental practitioners. Our preceding investigation found that 14.3% of school-aged children have MIH. Based on this finding, we wanted to understand what other Romanian dental professionals think about this condition. Therefore, the aim of the present study was to assess the awareness, perception, and clinical management approaches of Romanian dentists toward MIH in order to inform future educational strategies and contribute to the development of dedicated preventive programs. Methods: To gain a comprehensive understanding of MIH in actual clinical settings, we developed and administered a questionnaire consisting of three distinct sections. Our objective was to capture the collective knowledge and perspectives of dental practitioners. We distributed the survey, which included 14 pertinent questions, to a large professional group of Romanian dentists. Results: This study collected responses from 219 Romanian dental practitioners (median age: 34 years) about their experiences with MIH. The vast majority (86.76%) had encountered MIH cases in their practice, with half reporting moderate prevalence among their patients. The most frequently observed complications were hypersensitivity (41.95%), pulp exposure (33.33%), and failed restorations (24.71%). While adhesive restorations were identified as the overall preferred treatment approach (70.00%), notable differences emerged in both clinical complications encountered and therapeutic approaches implemented across dental specialties. There was near-unanimous agreement on the importance of early MIH diagnosis (99.09%), and almost all participants (98.63%) expressed a desire for more information about this condition, demonstrating high awareness and concern about MIH among Romanian dental professionals. Conclusions: This study highlights that general dentists, endodontists, and pedodontists encounter MIH patients frequently in their practice, emphasizing the critical need to enhance awareness and education about MIH among both dental professionals and the general public. Full article

Background: During the initiation of routine orthodontic treatment with fixed appliances, placing elastic separators (ESs) may lead to the patient experiencing considerable pain. Earlier studies evaluating the effects of low-level laser therapy (LLLT) on reducing pain caused by orthodontic ESs have reported contradictory results. The aim of our study was to evaluate the effect of a single application of LLLT on the experience of pain following ES placement. Methods: A double-blind, placebo-controlled randomized controlled trial was performed—with implementation of the split-mouth technique—where n = 33 volunteers (12 male and 21 female; aged between 19 and 36 years) were enrolled. ESs were placed at the mesial and distal surfaces of the first permanent molars in the upper or lower jaws. Jaws were divided into two quadrants; the treatment group received LLLT (using a GaAlAs diode laser, at a 980 nm wavelength, with 100 mW producing 6 J of energy; continuous wave), while the other quadrant served as the placebo side receiving a similar treatment, but without laser irradiation, immediately after separation. A questionnaire with a visual analogue scale (VAS; 0–100) was used for the assessment of pain (spontaneous pain and pain on mastication) scored for each first permanent molar directly after separation and after 6, 24, 48 and 72 h of both laser and placebo treatment application. Results: Mean VAS values were lower, but not significantly different, between the treatment vs. placebo groups for spontaneous pain at either measurement point (p > 0.05). Mean VAS values were significantly lower in the treatment groups for pain on mastication at the 6 (9.29 ± 12.65 vs. 19.07 ± 20.99; p = 0.025), 24 (21.96 ± 21.11 vs. 37.19 ± 26.35; p = 0.012) and 48 h (28.01 ± 21.40 vs. 42.60 ± 26.29; p = 0.016) measurement points. The analgetic effect of LLLT was most effective after 6 h, both in the resting position (−49% decrease) and during mastication (−51% decrease). Conclusions: A single application of LLLT with 6 J of energy may have beneficial effects on reducing the pain caused by orthodontic ESs used at the initiation of treatment with fixed appliances, especially during mastication, after 6–48 h following the separation procedure. Trial registration: clinicaltrials.gov ID NCT06816537 (date of registration: 7 February 2025, retrospectively registered). 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/Objectives: Fracture resistance is crucial for provisional crowns, especially under high-stress conditions like bruxism. While semi-permanent materials such as Luxacrown are designed for durability, their performance under extreme occlusal forces remains uncertain. This study uses finite element analysis (FEA) to evaluate the fracture resistance of five common provisional crown materials. Methods: A standardized digital model of a maxillary first molar was developed with uniform crown thickness. Twenty models were created to assess Unifast Trad (self-curing PMMA), Luxatemp Star (bis-acryl composite), Luxacrown (semi-permanent bis-acryl), Protemp 4 (nanofilled bis-acryl), and Telio CAD (CAD/CAM PMMA). FEA simulations evaluated vertical (250 N), lateral (225 N), diagonal (400 N), and bruxism-level (800 N) forces. Stress-to-strength ratios (SSR) and Von Mises stress distributions were analyzed to evaluate material performance and failure risk. Results: Telio CAD exhibited the highest fracture resistance, maintaining SSR values below 100% across scenarios. Luxacrown and Protemp 4 performed adequately under moderate loads but showed increased stress concentrations under bruxism-level forces. Luxatemp Star followed a similar trend, whereas Unifast Trad demonstrated the lowest resistance, accumulating significant stress in all conditions. Conclusions: Material selection is key to provisional crown fracture resistance. Telio CAD showed the highest durability, while Luxacrown and Protemp 4 performed well under moderate loads but struggled under extreme forces, raising concerns about semi-permanent materials. Luxatemp Star showed similar trends, and Unifast Trad, the weakest, is best for short-term use. Full article

Background: Geometric morphometric analysis, a methodology traditionally used in evolutionary studies, offers unprecedented precision in quantifying the morphological traits of human organs and tissues by identifying specific anatomical landmarks. Despite its potential, this approach has not yet been applied in medical or dental research. Materials and Methods: This pilot study analyzed 76 permanent upper first molars (M1) from Italian individuals (38 males and 38 females), selected for their completeness, minimal wear (stage 1), and absence of pathological conditions or non-metric traits. Each individual contributed two contralateral molars: the left molar (Group A) and the right molar (Group B). The molars were scanned using a Sinergia Scan Advanced Plus optical scanner with 5 μm accuracy. The scans were processed with the Dental Scan 7.0 software to generate high-resolution STL files, followed by refinement in Meshlab to preserve the morphological integrity of the 3D models. The geometric morphometric analysis was performed using the Viewbox software, thereby enabling the placement of anatomical landmarks and semilandmarks to quantify and compare molar morphology with exceptional precision. Results: The analysis confirmed that contralateral molars exhibit high morphological similarity, with significantly smaller variability compared to molars from different individuals. Among the specific traits analyzed, the distolingual cusp (hypocone) showed the greatest variation, followed by the mesiolingual cusp (protocone). No significant differences were observed between males and females in the degree of similarity between contralateral molars. Conclusions: This pilot study highlights the potential of geometric morphometric approaches to enhance our understanding of the dental variation between sexes and across human populations, thereby improving clinical applications and advancing toward personalized medicine. Full article

Introduction: In orthodontics, determining the parameters of tooth size and dental arch and conducting Bolton analysis is crucial for diagnosis, treatment planning, and patient outcomes. This study evaluates the accuracy and reliability of measuring dental-arch dimensions on digital models created using the CEREC Primescan intraoral scanner, compared to measurements taken from plaster models. Methods: The study included two types of dental models (plaster and intraoral scan) from sixty-three subjects. Impressions were taken to create plaster models, and the subjects’ mouths were scanned with the CEREC Primescan system (Dentsply Sirona, Charlotte, NC) to create digital models. Intra-arch measurements included tooth heights and widths, overjet, and overbite. The arch width and depth were examined at the first permanent upper or lower molar. The paired t-test and Bland–Altman plot were used to determine the accuracy, while intra-rater and inter-rater correlation coefficient values were calculated to assess the reliability of measurements from the intraoral scan compared to those from the plaster model. Results: For tooth heights, there was a statistically significant difference in only one measurement (tooth 34) between the plaster and digital models, with an average difference of 0.01 mm. For tooth widths, there was a statistically significant difference in only one measurement (tooth 15) with an average difference of 0.03 mm. The Bland–Altman plots of almost all of measurements of tooth heights and widths showed that differences between the two models were within the limits of agreement. The inter- and intra-rater correlation coefficient values for measurements on the digital model were found to be statistically insignificant. Conclusion: Measuring dental dimensions on digital models obtained through the Primescan intraoral digital system yielded similar results to those obtained from plaster models and showed excellent reliability, indicating its potential application in clinical practice. Full article

Background/Objectives: Delayed tooth eruption (DTE) is a very challenging clinical situation, and the pathogenesis has been associated with local, systemic, and genetic factors. The aim of this presentation is to describe the management of such a case with delayed eruption of mandibular central incisors and canines. Methods: An 11-year-old female patient presented with DTE involving lower incisors (32, 42) and canines, seeking orthodontic treatment. Furthermore, lower permanent central incisors were congenitally missing while lower deciduous incisors were still in place. After a year-and-a-half of just monitoring the case and having suggested the extraction of deciduous first molars and canines, orthodontic treatment started with fixed appliances in the upper and lower jaw. First and second premolars gradually erupted after the precursor’s extraction. Lower canines and the two existing incisors were, after several months, surgically exposed and a gold chain apparatus was bonded on each one, while the closed eruption technique was chosen. A 0.17 × 0.25 stainless steel (SS) lingual wire, leaning on the buccal tubes of the lower molar bands and properly manipulated around them, was fitted in conjunction with the labial brackets and wires in order to facilitate the traction of the impacted teeth, which was carried out for one after the other using either an elastic chain or a second super-elastic wire. Results: All impacted teeth were finally restored to their proper place. The root of 71 did not present resorption, so the tooth was maintained in the lower arch while inter-proximal reduction was performed in the upper arch in the anterior region, in order to anticipate the lower missing incisor. Finally, a stable occlusion with proper contacts was achieved. Conclusions: Proper diagnosis, on-time extractions of deciduous teeth, and a well-designed treatment plan regarding space management and orthodontic traction of impacted teeth contributed to successful treatment outcomes in this DTE case. Full article

Background/Objectives: In Marburg (Hesse, Germany), the selective intensive preventive program (SIP) with fluoride varnish applications had to be interrupted due to the COVID-19 pandemic. The aim of this retrospective anonymized evaluation was to investigate possible effects of SIP interruption on oral health in socially vulnerable 7- and 8-year-olds. Methods: The caries increment in 7- and 8-year-olds for the test group (N = 180) between last dental check-up before the interruption of SIP (02/2019–02/2020) and the first check-up after restart (01/2022–07/2022) were calculated from dental public health service data. The test group was compared to a control group of children (N = 215; same age and schools, with SIP, data collected between the school year 2017/18 and 2019/20). One dentist conducted the dental examinations. The University of Marburg ethics committee approved the study. The Mann–Whitney U test and Pearson’s chi-square test were used for statistical analysis. Results: There was no significant difference in the caries increment in the first dentition between the test and the control group for both age groups. In the different groups, a maximum of 61% of the children with caries experience were completely treated. There was no significant difference between the test and control groups in either the percentage of sealed first permanent molars or the degree of restoration. Conclusions: The interruption of SIP had no negative impact on caries increment. It is possible that the children examined went through the pandemic without a significant increase in tooth decay because the children were well-trained in tooth brushing since kindergarten. Full article