Dentistry Journal

Background/Objectives: When solving the problems of installing zygomatic implants after partial or full maxillectomy with subsequent attachment of a removable overdenture (ROD), computer simulation based on the finite element method (FEM) is an effective tool for treatment planning. In this study, stress-strain states of the ‘zygomatic bones–implants–splinting bar–ROD’ dental structure were evaluated under various loading conditions. Methods: A 3D FEM computer simulation was carried out to estimate stress-strain states of the elements of the dental structure and to study the effect of redistribution of the loads transferred from the ROD to the zygomatic bones through four implants. Results: That successive insertion and removal of the ROD caused identical stresses in the elements of the dental structure. Given the accepted level of critical stress of about 13 MPa, their values may be exceeded in the zygomatic bones during both processes. In the ROD, the equivalent stresses did not exceed the critical levels upon alternate loading of 50 N on the posterior teeth (both molars and premolars) under all biting and mastication. Taking into account the linear dependence of the applied load and the stresses in the ROD, it can be stated that its integrity is maintained until 118 N (or the generally accepted typical value of 100 N). Under the 90° biting angle, the equivalent stresses are below the critical level in all the studied cases; thus, the acceptable value increases to 213 N, but it is only 63 N at a biting angle of 45°. Conclusions: It has been established that the equivalent stresses in the zygomatic bones can exceed the critical stress level of 13 MPa. In addition, some practical recommendations and prospects of the study have been formulated. Full article

Background/Objectives: While dentistry plays a critical role in promoting oral health, it also contributes significantly to environmental degradation through high energy consumption, water usage, and reliance on disposable, non-recyclable materials. Periodontology, in particular, involves resource-intensive procedures such as full-mouth disinfection, frequent surgical interventions, and aerosol-generating instrumentation. The aim of the present narrative review is to synthesize current knowledge and delineate feasible, evidence-informed strategies to operationalize sustainability across the full spectrum of periodontal treatment settings. Methods: The electronic search of the present narrative review was performed across PubMed/MEDLINE, Web of Science, BioMed Central, Scopus, CINAHL, and Cochrane Library databases. Results: The review identified actionable sustainability strategies across pre-workplace (e.g., eco-conscious procurement and transport reduction), workplace (e.g., energy- and water-saving technologies, digital workflows, and pollution control), and waste management (e.g., reuse protocols, recycling, and sustainable material selection). Particular emphasis was placed on the role of dental education, life cycle assessments, and digital innovations. Conclusions: The transition toward sustainable periodontology requires the adoption of evidence-based practices and leveraging digital innovation to reduce the environmental impact while maintaining high standards of care. Full article

One of the most significant public health issues of the twenty-first century is antimicrobial resistance (AMR), which is responsible for thousands of deaths each year and undermines the efficacy of commonly used antibiotics. In dentistry, the frequent and sometimes inappropriate use of antibiotics, combined with the complexity of the oral microbiome, creates a high-risk environment for the development and spread of antimicrobial-resistant microorganisms. Although clinical infections have received most of the attention, dental unit waterlines, dentures, and orthodontic appliances are three reservoirs that play an important but underestimated role in this global crisis. These environments provide perfect conditions for biofilm formation and, further, the survival and growth of resistant microorganisms. This review aims to discuss the origins and mechanisms of AMR, the unrecognized role of these three reservoirs in dental settings, and their contribution to the AMR issue. It also highlights the necessity of strict infection control procedures and targeted antimicrobial stewardship strategies to overcome this growing threat. Full article

Background/Objectives: Standard dental practice is being reshaped by digital technologies, and artificial intelligence (AI) is emerging as one of the most challenging recent innovations. Methods: The present study assessed the interest of Romanian dentists in the integration of AI into their current practice through an anonymous questionnaire distributed to 200 respondents. The questionnaire addressed the integration of AI in dentistry by analyzing the following areas of intervention: stages of patient care, perceived impact on the doctor–patient relationship, data security, implementation costs, and the legislative framework. Results: The results showed that 53.6% of dentists reported low difficulties, 37.3% reported moderate difficulties, and 9.1% reported high difficulties with using digital tools. Dentists’ reported willingness to adopt AI-based solutions was as follows: 58.6% were very willing, 30% were moderately willing, and only 11.4% were not very willing. Currently, 80.5% already use digital techniques in their daily practice. The participants emphasized the need to maintain a strong doctor–patient relationship while recognizing the benefits of increased efficiency. They were aware of the risk of diminishing human connection and trust. Also, data security and the financial stress associated with implementing and maintaining new systems were seen as major obstacles. Conclusions: The dentists surveyed showed an increased interest in modern digital technologies, provided that there is a clear legal framework, a strong data protection system, and the preservation of the doctor–patient relationship based on trust and confidentiality that defines the medical profession. Full article

Background: Partial edentulism presents an ongoing clinical challenge, and the optimal choice of prosthetic rehabilitation remains a topic of debate. Purpose: This review compares three abutment configurations for removable dentures—natural teeth, implants, and mixed support. The goal was to determine which treatment offers the best longevity, lowest complication rates, and highest survival. Materials and Methods: A systematic search following PRISMA 2020 guidelines and the PICO framework was conducted using PubMed and Scopus, focusing on clinical studies of IARPDs published between 2022 and 2024. Studies were selected based on predefined eligibility criteria. Descriptive analysis of survival and complication outcomes was performed and represented graphically. Results: Nineteen studies were included: four on IARPDs, six on conventional RPDs, and five on IODs. Main parameters included prosthesis survival, abutment (tooth/implant) survival, and complication rates. IARPDs showed favorable implant survival and lower rates of abutment tooth loss than conventional RPDs. Conventional dentures demonstrated lower performance. IODs had the highest survival over mid-term follow-up periods. Discussion: IARPDs demonstrate clinical viability, especially in cases requiring strategic abutment preservation. Although the data are limited by sample size and short follow-up, IARPDs show potential advantages in preserving natural dentition and improving load distribution. Conclusions: IARPDs are a reliable treatment option for partial edentulism, combining implant support with removable versatility. More long-term studies are needed to strengthen current findings, but the existing evidence supports their use in contemporary prosthodontics, in selected cases. Full article

Background: The endodontic management of patients with complex systemic conditions represents a significant clinical challenge, particularly in cases involving combined endodontic-periodontal lesions and extensive root resorptions. This case report, accompanied by a recent and targeted literature analysis, describes the single-session treatment of an oncologic patient with multiple systemic comorbidities, presenting with a communicating periapical and endodontic-periodontal lesion (EPL), as well as external cervical root resorption (ECR). Methods: Root canal treatment (RCT), combined with ECR repair, was performed using bioceramic materials, via thorough management and planning with cone-beam computed tomography (CBCT) and the aid of an operating microscope. Results: At the 12-month follow-up, complete clinical and radiographic healing was observed, including regeneration of the periodontal ligament and full functional recovery of the tooth. Conclusions: Contrary to what has been reported in the literature, where several studies highlight lower healing rates in patients with systemic comorbidities undergoing endodontic treatment, the present case report demonstrates a favorable and stable outcome. Moreover, the possibility of concentrating the intervention into a single session represents an additional advantage for this category of patients, who often face limited physical and temporal resources due to their concurrent oncologic condition. Full article

Background/Objectives: Guided bone regeneration one of the most widely used techniques, relies on combining bone graft material with barrier membranes or meshes. The choice of the mesh material depends on the specific clinical situation. Among the available options, titanium membranes are recognized as one of the most effective in dental implantology. The latter can be categorized into two groups: commercial and individualized. Advancements in additive manufacturing make customized titanium meshes an attractive option for bone regeneration. Customized titanium meshes can be manufactured using three main methods: selective laser sintering (SLS), selective laser melting (SLM), and direct metal laser sintering (DMLS). This review aims to provide information about the differences between the production process and the clinical outcomes. Methods: This systematic review was conducted by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis for Scoping Reviews (PRISMA-ScR). Relevant articles were sought out in the Web of Science, PubMed, and Scopus databases. Results: A total of ten articles were included and thoroughly reviewed. The type of bone graft used, the manufacturing technique, the amount of bone gain, the healing time, and the intraoperative and postoperative complications are discussed. Conclusions: All the relevant studies demonstrated good and predictable results using augmentation with individualized titanium meshes manufactured via SLS, SLM, or DMLS methods. Full article

Background/Objectives: Impacted teeth are characterized by having more than three-quarters of root development completed, however failing to erupt or demonstrate imminent eruption, as evidenced both by clinical and radiographic evaluation. Canine impaction is an entity of clinical significance considering its potential to affect both oral function and facial aesthetics. If not appropriately managed, this condition may adversely impact functional occlusion and structural smile integrity. The purpose of the study was to investigate the prevalence of impacted and transmigrant canines in a Greek orthodontic cohort and identify potential sex-based differences. Methods: A total of 2594 panoramic radiographs and clinical records of consecutive patients in the mixed and permanent dentition stages, treated at the Department of Orthodontics of the Aristotle University of Thessaloniki, Greece, were retrospectively retrieved and analyzed to detect the presence of impacted and transmigrant canines. Patients lacking complete clinical records or panoramic radiograph, undergoing or had undergone orthodontic treatment, or presenting conditions affecting normal permanent dentition development, including pathological conditions, cleft lip and palate or hereditary disorders, were excluded. Results: At least one impacted canine was detected in 109 patients (67% females, 33% males), with a median age of 15 years (IQR: 13–18), documenting a 4.2% prevalence (6.97% females, 2.32% males). The frequency of maxillary canine impaction was 3.97%, while in the mandible a frequency of 0.46% was reported. The frequency of bilateral canine impaction was 1%, with it being present in 25.7% of patients with canine impaction. The prevalence of transmigrant canines was 0.11%, with detection solely in the mandible. A statistically significant sex difference was detected solely in the prevalence of impaction. Conclusions: Considering the implications of canine impaction, the epidemiological investigation of this entity may facilitate an early diagnosis and treatment. Full article

Background/Objectives: The management of immature teeth with wide apical foramina presents significant challenges in endodontic treatment due to difficulties in achieving a hermetic seal. The aim of this study was to evaluate void formation in apical plugs created using three calcium silicate-based materials—Biodentine, NuSmile NeoPUTTY, and Well-Root PT—applied with the help of manual, ultrasonic, or rotary file condensation (XP-endo Shaper) in 3D-printed immature teeth. Methods: Micro-computed tomography analysis was used to assess the internal, external, and total void percentage of material volume. The statistical analysis was performed using two-way ANOVA and the post hoc Bonferroni test. Statistical significance was set at p < 0.05. Results: The materials and techniques used individually do not significantly influence the formation of internal voids, but their combination does (F(4, 99) = 2.717, p = 0.034). Both factors and their interaction are significant for external voids (F(4, 99) = 4.169, p = 0.004), and all have a notable effect on total void percentages (F(4, 99) = 3.456, p = 0.012). No significant differences were observed in internal voids across the groups (p > 0.05), ranging from 0.635% to 1.078%. External voids varied significantly, with Well-Root PT and ultrasonic condensation showing the highest values with a significant difference (p < 0.05), while NeoPUTTY and Biodentine with XP-endo Shaper exhibited the lowest. Total voids remained below 4%, with no significant differences among manual condensation groups. Neither material type nor application technique consistently influenced void formation, except for Well-Root PT with ultrasonic condensation. Conclusions: These findings suggest that modern bioceramic materials and application techniques produce comparable, low-void apical plugs, with XP-endo Shaper showing promise for minimizing external voids. The interaction between material and application technique plays a crucial role during the creation of apical plugs. Full article

Background/Objectives: This scoping review aims to map existing AI applications in dental education, in student learning, assessment, and diagnostic training, identifying key limitations and challenges. Methods: Following the Arksey and O’Malley framework and PRISMA-ScR guidelines, six databases were searched in March 2025 using combinations of the following search words: “dental education,” “artificial intelligence,” “machine learning,” and “student assessment”. Inclusion was limited to English-language empirical studies focused on dental student education. Of 547 identified studies, 17 met the inclusion criteria. They were categorized into four domains: (1) Preclinical Training, (2) AI in Clinical, Diagnostic Training, and Radiographic Interpretation, (3) AI as an Assessment Tool and Feedback System, and (4) AI in Content Generation for Dental Education. Results: AI has positively influenced various domains, enhancing procedural accuracy, diagnostic confidence, assessment efficiency, and content delivery. However, it struggles to assess nuanced competencies like dexterity and clinical judgment. The challenges faced include disparate definitions of AI, ethical and privacy concerns, model variability, and a deficiency of dental leadership in AI development. At present, most tools are engineered by computer scientists and may not align effectively with the priorities of dental education. Conclusions: AI holds significant potential to enhance dental education outcomes. However, to guarantee its relevance and reliability, it requires standard frameworks, ethical oversight, and clinician-led development. Future research should concentrate on implementing real-time AI-driven feedback systems during preclinical training and advocate for more precise definitions to support consistent AI application and evaluation in dental education. Full article

Background/Objectives: There are many commercial mouthrinses, used for a variety of purposes, including antiseptic activity. The objective of this study was to determine the antibacterial activity of various TheraBreath™ oral rinses against the cariogenic bacterium, Streptococcus mutans, and saliva-derived microbial communities, and their antibiofilm activity against S. mutans in vitro biofilms. Methods: Bactericidal activity against planktonic S. mutans was assessed by colony counting after 30 and 2 min exposures to mouthrinses. Ten saliva samples were exposed to mouthrinses for 30 s and plated aerobically on blood agar and Mitis Salivarius agar. Mature biofilms of S. mutans were treated with mouthrinses for 15 min followed by fluorescent vitality staining and polysaccharide measurement, followed by crystal violet staining for measurement of total biofilm remaining. Statistical analysis was performed using Kruskal–Wallis with Dunn’s multiple comparisons test comparing all mean ranks (α = 0.05). Results: TheraBreath™ Fresh Breath, Healthy Smile, and Dry Mouth exhibited no significant antibacterial activity. TheraBreath™ Healthy Gums showed antibacterial activity against S. mutans and microbes from saliva samples similar to Listerine^® Naturals at all exposure times. Whitening Fresh Breath showed intermediate killing of S. mutans after 30 min in liquid but not after 2 min or against salivary microbes. Live/Dead fluorescence vitality staining showed that Healthy Gums and Whitening Fresh Breath had antibacterial activity against mature biofilms of S. mutans statistically similar to Listerine^® Naturals and Colgate^® Total; however, Whitening Fresh Breath did not have significant killing compared to PBS. Conclusions: TheraBreath™ Healthy Gums demonstrated similar antiseptic activity levels to other antiseptic-claiming commercial rinses. Whitening Fresh Breath was comparable but unable to kill in short exposure times. Full article

Although dental implants appear to be an alternative for treatment of tooth loss, fixed prosthetic restorations are an irreplaceable part of oral rehabilitation. Regarding the EU directives concerning cobalt health risks, titanium alloys may be an alternative to cobalt–chromium and nickel–chromium for metal–ceramic dental restorations. The presented review briefly describes the specific properties of titanium, and the challenges met during production and use of titanium–ceramic fixed prosthetic restorations. Full article

Background. The use of zygomatic implants (ZIs) provides a highly predictable treatment option for rehabilitation in patients with severe atrophic maxillae. However, these long implants can potentially cause a number of more serious complications than those seen with conventional dental implants. The aim of this study is to report a case of peri-zygomatic cutaneous fistula following placement of monolateral double zygomatic implants and to analyse the available literature on this complication. Methods. The 55-year-old patient was treated with placement of 3 ZIs, two on the left side. Left periorbital swelling with pain appeared 10 days after surgery with progressive worsening of symptoms. After antibiotic treatment, she developed a left cutaneous fistula with purulent discharge. CT showed two ZIs on the left side with the apical portions in close contact with a 1 cm-wide portion of resorbed zygomatic external cortex and a layer of granulation tissue. Results: Due to the limited amount of bone involved by the fixation tip, the left ZIs were removed and the skin fistula repaired. The patient healed without complications but required prosthesis replacement. Conclusions. After conducting a literature review, peri-zygomatic fistulas seem to be more common in patients with two ZIs placed on the same zygoma. In this case, the amount of available zygomatic bone is relatively limited; the bone drill holes can often be too close together and cause overheating, leading to inter-implant bone resorption and infection, with further orbito-zygomatic fistula development. The authors identified the lack of distance between ZI fixtures as one of the main causes of extraoral ZI infection. Full article

Background: The present study investigated the relation between dental inclination, colorimetric variation, and aesthetic perception according to the modification of incisor inclination. Smile aesthetics, shaped by morphological factors and patient perception, are vital for social attractiveness and treatment success. This study aimed to assess the effect of varying head tilt on the perceived colour of upper central incisors by simulating changes in torque of the tooth, as well as evaluate factors influencing the perception of an aesthetic smile, including morphological characteristics and gingival aesthetic parameters. Methods: The study was comprised of three stages: colour analysis, evaluation of micro- and mini-aesthetic smile features, and an image-based assessment to determine evaluator perceptions and overall smile attractiveness. A sample of 50 students with complete, lesion-free anterior dentition was analysed. To simulate the effect of orthodontic torque changes during colour analysis, subjects tilted their heads downward and upward, representing palatal and buccal crown torque, respectively. Standardized macro-intraoral photographs were captured under controlled lighting conditions using a DSLR camera stabilized on a tripod in the different positions: the neutral head position (p0), 15° upward (p + 15), and 15° downward (p − 15). Digital colour analysis was conducted in the CIELAB colour space (L*, a*, b*). In the next stage, focusing on micro- and mini-aesthetic evaluation, an additional 50 smiles were generated using artificial intelligence via the SmileCloud program—one digitally enhanced smile per subject—complementing the initial set of 50 spontaneous smiles. These 100 smile images were evaluated by 50 laypersons and 50 dentists using a visual analogue scale via an online questionnaire, in order to assess perceptions, determine smile attractiveness, and quantify gingival aesthetic parameters. Results: The statistically significant regression results are as follows: those for the L* values in all three head inclinations: downward (−15 degrees), upward (+15 degrees), and total tilting (−15 to +15 degrees), as well as for the a* values for downward tilting and the b* values for total tilting. When the head is tilted downwards, the central incisors are positioned retrusively, and the L* b* values reveal a darker and more yellowish appearance, whereas, with the head tilted upwards, the central incisors protrude, and L* a* values indicate a brighter and more greenish appear. In the evaluation stage of the smile aesthetics study, no significant differences were observed in the judgments between laypersons and dentists or between males and females. Smiles with a high or average anterior line, parallel arc, upward lip curvature, visible first/second premolars, a smile index of 5.08–5.87, and symmetry score of 1.04 were rated as more attractive. Significant asymmetries were observed between upper dental hemi-quadrants in gingival contour and interdental papilla height, highlighting subtle morphological variations relevant to smile aesthetics. Conclusions: Aesthetic assessment revealed that the findings suggest a measurable impact of head position on dental colour perception and aesthetic evaluation. Evaluator variables including profession and gender exerted negligible effects on aesthetic perception, whereas smile attractiveness features and gingival aesthetic parameters demonstrate significant clinical applicability in patient management. Full article

Background/Objectives: The effectiveness of clear aligner therapy depends significantly on the precision of force delivery through the aligner–attachment interface. This study aimed to evaluate the microscopic compatibility between different orthodontic clear aligner materials (Duran+ and Zendura FLX) and attachment designs (rectangular and optimized) using scanning electron microscopy (SEM). Methods: Fifty-six samples were divided into four groups: rectangular attachments with Duran+ aligners (n = 14), rectangular attachments with Zendura FLX aligners (n = 14), optimized attachments with Duran+ aligners (n = 14), and optimized attachments with Zendura FLX aligners (n = 14). Attachments were bonded to bovine incisors using standardized protocols. Clear aligners were thermoformed at 220 °C for 40 s. Cross-sectional samples were analyzed using SEM at 250× magnification. Gap measurements were taken at seven points for rectangular attachments and five points for optimized attachments. Results: Gap measurements ranged from 14.75 ± 1.41 µm to 91.07 ± 3.11 µm. Zendura FLX demonstrated significantly better adaptation than Duran+ with rectangular attachments (42.10 ± 1.07 µm vs. 44.52 ± 1.51 µm, p < 0.001). Optimized attachments showed better overall adaptation than rectangular attachments. All combinations showed regional variation with the largest gaps at gingival borders (67.18–91.07 µm) and the smallest at flat buccal surfaces (14.75–20.98 µm). Conclusions: Perfect adaptation was not achieved with any material–attachment combination tested. Material selection and attachment design significantly influence microscopic adaptation, with multi-layer materials and optimized geometries showing superior performance. These findings provide mechanical explanations for clinical limitations in clear aligner therapy. Full article

Objectives: This article introduces a digital technique for virtual articulator mounting by employing the scan of a facebow worn by the patient as a virtual reference. Methods: The digital technique enables the transfer of the maxillary arch orientation relative to the cranial base into a CAD-CAM environment (Ceramill Mind; AmannGirrbach), without the need for ionizing radiation or identification of facial landmarks. By digitally aligning the intraoral scans of the dental arches (Trios 4; 3Shape) with a 3D facial scan and the scanned facebow in position (Artex; AmannGirrbach), clinicians can reproduce the cranium-to-maxilla spatial relationship accurately and intuitively. Results: This radiation-free protocol provides virtual cross-mounting and allows for the use of a semi-adjustable articulator within common CAD-CAM software. Conclusions: Given that intraoral scanners, facial scanners, and design software with articulator simulation are becoming more available in modern clinical workflows, this method introduced here could be a viable radiation-free and easy-to-use alternative. However, larger cohorts and standardized testing protocols are needed to determine its clinical reproducibility and reliability. 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

Background/Objectives: This study aimed to evaluate the efficacy of a 445 nm diode laser in enhancing enamel resistance to acid-induced demineralization and to investigate the associated compositional and structural modifications using scanning electron microscopy (SEM), electron spectroscopy for chemical analysis (ESCA), and X-ray diffraction (XRD) crystallographic analysis. Methods: A total of 126 extracted human teeth were used. A total of 135 (n = 135) enamel discs (4 × 4 mm) from 90 teeth were assigned to either a laser-irradiated group or an untreated control group for SEM, ESCA, and XRD analyses. Additionally, 24 mono-rooted teeth were used to measure pulp temperature changes during laser application. Laser irradiation was performed using a 445 nm diode laser with a pulse width of 200 ms, a repetition rate of 1 Hz, power of 1.25 W, an energy density of 800 J/cm², a power density of 3980 W/cm², and a 200 µm activated fiber. Following acid etching, SEM was conducted to assess microstructural and ionic alterations. The ESCA was used to evaluate the Ca/P ratio, and XRD analyses were performed on enamel powders to determine changes in phase composition and crystal lattice parameters. Results: The laser protocol demonstrated thermal safety, with minimal pulp chamber temperature elevation (0.05667 ± 0.04131 °C). SEM showed that laser-treated enamel had a smoother surface morphology and reduced acid-induced erosion compared with controls. Results of the ESCA revealed no significant difference in the Ca/P ratio between groups. XRD confirmed the presence of hydroxyapatite structure in laser-treated enamel and detected an additional diffraction peak corresponding to a pyrophosphate phase, potentially enhancing acid resistance. Results of the spectral analysis showed the absence of α-TCP and β-TCP phases and a reduction in the carbonate content in the laser group. Furthermore, a significant decrease in the a-axis lattice parameter suggested lattice compaction in laser-treated enamel. Conclusions: Irradiation with a 445 nm diode laser effectively enhances enamel resistance to acid demineralization. This improvement may be attributed to chemical modifications, particularly pyrophosphate phase formation, and structural changes including prism-less enamel formation, surface fusion, and decreased permeability. These findings provide novel insights into the mechanisms of laser-induced enhancement of acid resistance in enamel. Full article

Backgroud: The aim of this study was to create an accessible, simple and reliable method for assessing the relative density of bone tissue in dentistry based on the analysis of digital panoramic radiographs. Methods: Measurement of average gray values on orthopantomograms was carried out using ImageJ Version 1.54i software. To estimate the relative bone density, functions for selecting regions of interest (ROI), calculating the area of selection, and statistics of the selected area were used. Statistical characteristics of samples and testing of hypotheses using statistical criteria were performed using Microsoft Excel. Results: we found that when manually selecting the reference and comparison areas for areas without signs of pathological changes in bone tissue, the average standard deviation was 0.058, and the coefficient of variation was 0.055 ± 0.011%, which makes the choice of the jaw angle as a reference more preferable. The average relative bone density of the assessed defective areas to the jaw angle was 0.64 ± 0.11, and the average relative bone density of the areas without pathology to the jaw angle was 1.052 ± 0.058. Conclusions: a research protocol was developed and justified using the ImageJ software package, which establishes a strict procedure for quantitative assessment of relative bone density based on the results of digital panoramic radiography. The proposed protocol can be used to monitor the condition of bone tissue after all types of dental treatment over time. Full article