Search Results (410)

The dental pulp–dentin complex is a dynamic tissue system whose structure and biological functions evolve over time under physiological, molecular, and environmental influences. This study aimed to characterize age-related alterations in apoptotic, inflammatory, and autophagy-associated signaling pathways, alongside nanoscale mechanical changes, and to evaluate their potential impact on pulp tissue homeostasis and cellular adaptive capacity. Materials and Methods: Human teeth (n = 90) were divided into three age groups: young (≤17 years), mature (18–50 years), and old (>51 years). Immunohistochemistry was performed to assess the expression of CD34, BID, Caspase-8, NFκB, STAT3, JAK1, COX-2, LAMP2, and MAP LC3II. Nanoindentation and atomic force microscopy (AFM) were used to measure dentin hardness and modulus of elasticity. Results: BID expression increased with age, whereas Caspase-8 showed a relative decrease (p < 0.05). Anterior teeth exhibited higher marker positivity than molars for BID (p = 0.029), Caspase-8 (p = 0.004), STAT3 (p = 0.001), and JAK1 (p = 0.026). Mechanical analysis revealed the lowest modulus of elasticity in young root dentin and the highest in old coronal dentin, reflecting progressive age-dependent structural changes. Conclusions: Aging of the dentin–pulp complex involves coordinated modulation of apoptotic, autophagic, and inflammatory pathways, closely linked to altered mechanical properties. This interplay likely influences pulp vitality and adaptive cellular responses, highlighting potential targets for age-adapted dental therapeutic strategies. Full article

Background: The application of veneer restorations over previously composite-restored anterior teeth presents significant clinical challenges, particularly in achieving optimal marginal sealing. Aim: This in vitro study aimed to evaluate the marginal integrity and sealing ability of different 3D-printed resin veneer restorations on sound versus composite-restored anterior teeth. Materials and Methods: Eighty freshly extracted human anterior teeth (40 central incisors and 40 canines) were randomly assigned into two main groups: sound teeth and composite-restored teeth. All the teeth received 3D-printed resin veneer restoration utilizing two different types of 3D-printed resin (GC Temp Print, GC, Tokyo, Japan; and Varseosmile Triniq, BEGO GmbH & Co., Bremen, Germany). The specimens were then subjected to microleakage, marginal fitness, cement void, and cement loss testing. Results: There were no statistically significant differences among all examined groups. Microleakage scores were predominantly 0 across all groups, with median values of 0 at both cervical and proximal surfaces. Marginal fitness showed fit percentages ranging from 20% to 100%, while cement voids and cement loss were rare events (<10%). Statistical analysis confirmed no significant differences between groups (p > 0.05), with p-values ranging from 0.151 to 1.000. Conclusions: No, the presence of pre-existing composite restorations did not adversely affect 3D-printed veneer performance. The marginal integrity and sealing ability of two different 3D-printed resin veneers are not affected by the presence of previous composite restoration on cervical and proximal surfaces for both incisor and canine teeth. 3D-printed veneers applied to sound and restored teeth showed good marginal integrity and proper sealing ability. Full article

This study quantified projection-dependent geometric distortion induced by vertical camera angulation in two-dimensional (2D) dental image acquisition and evaluated its implications for integration with three-dimensional (3D) CAD/CAM and artificial intelligence (AI)-driven workflows. To our knowledge, this study is among the first to use quantitative methods to characterize projection-induced distortion across the dental arch as a function of vertical camera angulation. Fourteen fully dentate casts were photographed at nine standardized vertical angulations using a controlled acquisition setup based on the standardized occlusal plane angle (SOPA). Tooth surface areas were measured through digital tracing and analyzed with a mixed-effects model (α = 0.05). Significant associations were identified between vertical camera angulation and measured tooth surface area for all teeth except canines (p < 0.05 for all except canines). Anterior teeth demonstrated increased apparent surface area at superior camera angulations, whereas posterior teeth were more prominently represented at inferior angulations. Central incisors, lateral incisors, and first premolars exhibited maximal visibility above the occlusal plane, while second premolars and molars were more optimally visualized below it. These findings indicate that vertical camera angulation induces non-uniform, region-specific geometric distortion across the dental arch. From a computational perspective, these distortions represent a systematic source of variability in 2D photographic datasets used in CAD/CAM workflows, virtual smile design, and AI-assisted image analysis. Because modern machine learning systems depend on geometrically consistent input data, uncorrected projection-induced distortion may reduce the reliability and generalizability of downstream algorithmic outputs. Accordingly, the present findings establish a quantitative basis for recognizing projection-induced variability in 2D dental photographs and support future development of geometry-aware calibration strategies for 2D-3D digital integration. AI-assisted correction represents a future translational direction contingent upon explicit alignment between acquisition geometry, image formation, and computational modeling. Full article

Background/Objectives: Dental implants are a predictable treatment modality for missing teeth, and the crown emergence angle may affect peri-implant tissue health. This study evaluated the influence of crown emergence angle on marginal bone loss (MBL) and the corticalization index (CI) at 3-month and 5-year follow-ups, considering restoration type and implant location. Methods: Records from 155 patients treated with MIS implants were analyzed retrospectively. The primary outcome was marginal bone loss (MBL) at 60 months after loading; secondary/exploratory outcomes included MBL at 3 months and the Corticalization Index (CI) at 3 and 60 months. Three prosthodontic restorations were included: single crowns, splinted crowns, and bridges. Intraoral radiographs were used to measure crown emergence angle, MBL, and CI. Results: Recorded emergence profile was 32° ± 10°. Marginal bone loss increased over time but did not differ significantly among restoration groups. No significant relationship was found between emergence angle and MBL for single crowns (p = 0.369) or splinted crowns (p = 0.176). For bridges, a weak but statistically significant relationship was observed (p = 0.042). CI increased over time in all groups, without significant differences by restoration type. Restoration type was significantly associated with anterior/posterior implant location (p = 0.0004): single crowns predominated anteriorly, whereas splinted crowns and bridges were more frequent posteriorly. No significant association was found for maxilla versus mandible (p = 0.077). Conclusions: Within the limitations of this retrospective radiographic analysis, no clinically meaningful association was observed between emergence angle and MBL for single or splinted crowns. For bridges, the observed association was statistically significant but weak and should be interpreted cautiously. Other biological, biomechanical, and systemic factors may play a greater role in peri-implant tissue stability than emergence angle alone. Full article

Background/Objectives: Multiple impacted teeth are defined as the sequential impaction of more than two teeth in the alveolar bone, whether unilateral or multilateral. Multiple impactions are an uncommon and rare phenomenon demanding thorough treatment planning and careful execution, but data on the prevalence of multiple impactions is scarce in the literature. In cases of multiple impactions, clinicians generally perform a 3D assessment using CBCT to determine tooth positions, establish a sequence of surgical exposures, implement suitable traction, and utilise appropriate biomechanics. A multidisciplinary approach between orthodontists and oral surgeons is essential to achieve optimal results. Methods: This case report presents non-syndromic multiple impactions of three upper left permanent anterior teeth—21, 22, and 23—along with a retained supernumerary tooth preventing their eruption and a fused primary tooth. The primary teeth and the impacted supernumerary tooth were surgically removed. A digitally designed transpalatal arch was used to preserve the space and to act as anchorage for the orthodontic traction. After an 8-month observational period without spontaneous eruption, surgical exposure was carried out using the closed exposure technique. Subsequently, elastic traction was performed, guiding the impacted teeth into the dental arch. Results: The multiple impacted teeth were successfully aligned in the dental arch, achieving symmetry in the frontal segment while preserving periodontal health. In order to ensure stability during the retention period, thermoformed retainers were used. Conclusions: Each complex and rare clinical case poses a challenge to orthodontists and is important for the scientific literature as it provides valuable clinical experience. Full article

Background and Clinical Significance: Dental trauma presents a considerable challenge for clinicians due to the diverse and complex effects on teeth. Effective management often requires the collaboration of multiple specialists, including endodontists and orthodontists. Case Presentation: This case report presents the interdisciplinary management of a complex dental trauma case involving three permanent maxillary anterior teeth. Unlike most reports of dental trauma, this case includes complete pre-trauma diagnostic records, providing valuable baseline information for treatment planning and outcome assessment. A 15-year-old female patient was examined in the orthodontic clinic, with comprehensive diagnostic records being obtained at the initial visit. Before the commencement of active orthodontic therapy, the patient experienced an extraoral traumatic incident. Clinical and radiographic assessment revealed concussion and traumatic mobility of the upper right canine, intrusive luxation of the upper right lateral incisor and extrusive luxation with increased mobility of the upper right central incisor. Taking into consideration treatment alternatives, an orthodontic–endodontic approach was preferred. Conclusions: The successful management of complex dental trauma affecting multiple permanent teeth requires interdisciplinary collaboration. The clinical significance lies in the potential long-term consequences on both tooth function and aesthetics, which can impact patient well-being. Full article

Background/Objectives: Photobiomodulation (PBM) is a biologically plausible adjunct for modulating orthodontic tissue response, but its role in conventional clear aligner therapy remains uncertain. This narrative review summarises the mechanistic rationale and clinical evidence on PBM used with clear aligners, focusing on treatment efficiency, predictability, patient-centred outcomes, and biological safety. Methods: Scopus was searched using PBM/low-level laser terms combined with orthodontics and clear aligners. Titles and abstracts were screened for human studies evaluating PBM as an adjunct to conventional staged clear aligner therapy and reporting treatment duration or alignment efficiency, tracking/predictability (for example, additional aligners, refinements, or fit-related outcomes), pain, or biological safety. Eight aligner-based clinical studies formed the core set. Results: The included studies comprised case reports, retrospective cohorts, pilot investigations, and one historical prospective nonrandomized comparison. Most evaluated short daily sessions of home-use near-infrared LED PBM, while some used external laser-based or combined adjunct protocols. Some studies reported shorter treatment duration, faster alignment, or fewer finishing aligners in PBM users, but these findings were difficult to attribute to PBM alone because altered tray-change intervals and close monitoring were common co-interventions. Aligner-specific pain outcomes were inconsistently reported. Limited safety data, based mainly on one retrospective pilot cohort assessing anterior teeth, found no statistically significant difference in root-volume change between PBM users and controls. Conclusions: PBM has been investigated as a potential adjunct in clear aligner orthodontics, but the available evidence remains preliminary, heterogeneous, and largely non-randomised. No high-quality randomized clinical evidence currently supports the clinical effectiveness or routine use of PBM in clear aligner orthodontics. At present, PBM should be regarded as an investigational adjunct rather than an established clinical recommendation, pending larger and better-designed trials with standardised device-specific protocols, objective adherence measures, movement-specific analyses, and longer follow-up for safety and patient benefit. Full article

Background/Objectives: Delivering consistent preclinical instruction for implant attachment procedures can be challenging in large dental cohorts. This report describes the development and implementation of institutionally produced training tools designed to support Locator housing pick-up exercises for second-year predoctoral dental students. Methods: Modified typodont-based simulation tools were integrated into the preclinical curriculum. Clear dentures and gypsum models were fabricated to allow visualization of seating relationships and identification of common interferences. Complete seating of the denture was verified using inspection windows, flange evaluation, and polyvinylsiloxane disclosing materials before housings were incorporated with autopolymerizing acrylic resin. After each session, components were collected, inspected, and prepared for reuse in subsequent cycles. Learner perceptions were obtained through an anonymous voluntary survey. Results: The configuration enabled visualization of seating conditions and identification of misalignment during the exercise. Removal of anterior teeth reduced material use and emphasized posterior stabilization during the pick-up procedure. Of 83 learners, 28 completed the survey (34% response rate), with responses tending toward agreement across items (mean range: 4.5–4.9/5), indicating favorable learner perceptions of the exercise and its organization within the scheduled laboratory period. Across three academic cycles, six dentures required replacement, whereas all gypsum models remained serviceable and no additional fabrication was necessary. Conclusions: This structured simulation approach provided an alternative method for delivering Locator housing pick-up training in a high-volume preclinical environment. The model allowed repeated implementation of the exercise across academic cycles. Full article

This case report describes a digital workflow for the aesthetic rehabilitation of a 30-year-old male patient with unaesthetic anterior teeth. The treatment incorporated AI-assisted smile design software (SmileCloud Biometrics) for 2D/3D digital planning and patient communication. Six lithium disilicate veneers (IPS e.max CAD) were fabricated using CAD/CAM technology following mock-up-guided minimally invasive preparation (0.2–0.9 mm reduction). The restorations were adhesively cemented under rubber dam isolation. One-week follow-up confirmed aesthetic integration, occlusal harmony, and patient satisfaction. This case illustrates how digital workflows with AI-assisted tools can support veneer rehabilitation through data-informed planning and conservative preparation while maintaining aesthetic outcomes. Full article

Background: Finite element analysis (FEA) has become an important tool in restorative dentistry for investigating stress distribution in teeth and dental restorations. However, the accuracy of such analyses strongly depends on the anatomical fidelity of the underlying tooth models, which is often limited in simplified geometries. The objective of this study was to develop an anatomically accurate three-dimensional tooth model based on micro-computed tomography (micro-CT) data and to evaluate the biomechanical behaviour of sound and composite-restored teeth under clinically relevant loading conditions. Methods: A human tooth was scanned using high-resolution micro-CT imaging. Enamel, dentin, and pulp were segmented and reconstructed into three-dimensional geometries, which were further refined using computer-aided design (CAD) tools. The resulting models were imported into a finite element environment for mechanical simulation. Static loading conditions were applied to both sound and composite-restored tooth models, including a vertical load of 200 N and an oblique load of 200 N applied at a 45° angle to the tooth crown. Von Mises stress distributions were evaluated to characterize stress concentration patterns. Results: Finite element simulations revealed maximum von Mises stresses of approximately 140 MPa, predominantly localized in the coronal regions of the tooth. Oblique loading produced increased and more asymmetric stress concentrations than vertical loading, particularly in the anterior and posterior crown regions. While overall stress distributions were comparable between sound and composite-restored teeth, locally increased stress levels were observed in restored models under oblique loading. Conclusions: Anatomically accurate, micro-CT-based finite element tooth models provide a robust framework for biomechanical analysis in restorative dentistry. The presented workflow enables detailed evaluation of stress distribution in composite-restored teeth and may contribute to improved understanding and optimization of restorative materials and treatment strategies. Full article

Aim: The aim of this study is to evaluate the effect of restorative crown materials with different elastic moduli on stress distribution in dentin and supporting tissues of pulpotomized primary anterior teeth under multi-directional loading conditions using the three-dimensional finite element analysis method. Materials and Methods: A three-dimensional model of a maxillary primary central incisor was created based on anatomical data. A clinical pulpotomy scenario was simulated using mineral trioxide aggregate (MTA) and resin-modified glass ionomer cement. Three models were analyzed: healthy tooth (control), Bioflx crown, and prefabricated zirconia crown. Frontal, oblique, and vertical loads were applied to represent functional and traumatic conditions. von Mises and principal stress distributions in the crown, dentin, and supporting tissues were evaluated. Results: In the prefabricated zirconia crown group, higher von Mises stress values were observed under all loading conditions, with significant stress concentrations particularly in the cervical region. In contrast, the Bioflx crown group exhibited lower stress values and a more homogeneous stress distribution. While the stress patterns in the Bioflx group were found to be closer to those of the control group, more localized stress accumulation was observed in the zirconia crowns. No significant differences were observed between the groups in the bone tissue. Conclusions: The elastic modulus of restorative materials plays a decisive role in the stress transfer mechanism. It is believed that materials with dentin-like mechanical properties may provide a more balanced and physiological stress distribution. Multi-directional loading analysis highlights the importance of evaluating the biomechanical behavior of restorative materials under more realistic conditions. Further advanced experimental and clinical studies are needed to clinically validate these findings. Full article

Plaque-disclosing agents are widely used to enhance visualization of dental biofilm. However, their chromogenic components may adhere to enamel surfaces, resulting in transient extrinsic discoloration. This study evaluated the extent and short-term recovery of such discoloration and compared three removal modalities in terms of enamel color change (CIEDE2000, ΔE₀₀), surface roughness (Ra), and gloss (GU). Extracted human anterior teeth with intact buccal enamel were stained using an erythrosine-based disclosing agent and randomly allocated into three groups (n = 15): manual brushing with conventional toothpaste, rubber-cup polishing with a perlite-containing paste (1000 rpm, 5 s), or erythritol-based air-polishing (5 s; 50% power/100% water). ΔE₀₀ was measured at baseline, immediately after cleaning, and after 1 week of storage in artificial saliva. Ra and GU were recorded at baseline and post-cleaning. Data were analyzed using appropriate tests (p < 0.05). All modalities were associated with a reduction in visible discoloration without significantly affecting Ra or GU (p > 0.05). Immediate ΔE₀₀ values remained above commonly reported acceptability thresholds, indicating residual discoloration. Partial color recovery occurred after artificial saliva storage. Within the limitations of this study, the findings indicate no statistically significant differences among the tested procedures, without evidence of superiority of any single modality. Full article

This study presents the first bioarcheological analysis of the Mnogovalikovaia culture (Middle Bronze Age) from the North Pontic region, evaluating six human skeletons (six adult males) discovered in tumuli at Novosiolovca, Burlăceni, and Ordășei (Republic of Moldova). Dental analysis reveals moderate-to-advanced occlusal wear, chipping on posterior teeth, and anterior teeth modifications indicating both dietary practices and extramasticatory activities. The characteristics of the dental morphology, including non-metric dental traits (i.e., degree of cusp expression, presence of supernumerary cusps, bilateral asymmetry and the occlusal surface shape of maxillary and mandibular second molars (M2) highlight population-specific features influenced by genetic and environmental factors. Traces of ochre on skeletons suggest specific funerary practices. The study fills a significant gap in the understanding of Mnogovalikovaia communities, providing important data on their biological and cultural characteristics, lifestyle, and funerary practices. These findings also represent a basis for future research on this population, requiring larger samples and biomolecular analysis. Full article

Objective: The objective of this study is to evaluate the biomechanical effects of different attachment placement strategies using rectangular attachments on palatal root torque control of maxillary central and lateral incisors with clear aligners. Methods: Three-dimensional finite element analysis was performed to simulate simultaneous 1° palatal root torque of maxillary central and lateral incisors. Six attachment configurations were evaluated: no attachment (control), canine-only, both incisors, central incisor-only, lateral incisor-only, and all anterior teeth. Three-dimensional tooth displacement and torque expression were analyzed across 200 iterative simulations. Model validation was confirmed through mesh convergence analysis and comparison with published studies. Results: Only the control and canine-only groups simultaneously achieved the appropriate torque direction for both incisors. Attachments on central incisors produced reverse torque, with the central incisor-only group showing the most severe magnitude, while the control and canine-only groups achieved expected directions, validating model reliability. Lateral incisors exhibited different responses, including reverse torque in the lateral incisor-only group. The canine-only attachment demonstrated the most balanced torque expression. Increasing anterior attachments was associated with greater extrusion and canine displacement. Conclusions: Attachment placement using rectangular attachments significantly influenced torque expression during palatal root torque. Central and lateral incisors responded differently to attachments, and certain configurations produced reverse torque. For small torque movements (1–2°), a “less is more” approach using rectangular canine attachments for anchorage proved most effective, suggesting that anchorage may be more critical than incisor attachments for anterior torque control. Full article

Background/Objectives: This study aimed to evaluate the immediate effects of a 2-hinged expander activated with the alternate rapid maxillary expansion–constriction (Alt-RAMEC) protocol on craniofacial structures and the soft tissue periodontium in adolescents with skeletal Class III malocclusion characterized by maxillary retrusion. Methods: Lateral cephalograms obtained at baseline (T0) and immediately after treatment (T1) from 15 adolescents (6 females, 9 males; mean ages 12.6–13.1 years) treated with a 2-hinged expander using a 9-week Alt-RAMEC protocol were analyzed. A control group consisted of 27 untreated Class III individuals (7 females, 20 males; mean ages 12.5–12.6 years). Sagittal and vertical skeletal, dental, and soft tissue measurements were assessed using a Cartesian coordinate system. Periodontal parameters of supporting teeth were evaluated at T0 and T1. Statistical analysis was performed using the Mann–Whitney U and Wilcoxon tests (p < 0.05). Results: Significant anterior maxillary displacement was observed in the treatment group compared with controls (p < 0.01), accompanied by increases in overjet and Wits appraisal (p < 0.05), while mandibular position remained unchanged. The upper lip advanced in accordance with skeletal changes (p < 0.05). Gingival index, bleeding index, and probing pocket depth increased significantly in supporting teeth (p < 0.05), whereas plaque index remained stable (p > 0.05). Conclusions: The 2-hinged expander combined with a 9-week Alt-RAMEC protocol induces immediate skeletal maxillary advancement in growing Class III patients with minimal dental compensation. Short-term periodontal changes suggest a transient inflammatory response associated with appliance therapy. Full article