Search Results (44)

Background: Dental cracks are a common yet diagnostically challenging condition due to their asymptomatic clinical nature and difficulty in early detection. Accurate diagnosis is essential to prevent crack progression and potential tooth loss; however, no universally accepted diagnostic method exists. Objectives: To systematically evaluate the diagnostic methods used for detecting dental cracks and analyze their effectiveness and limitations according to the available scientific literature. Materials and Methods: A systematic review of diagnostic test accuracy studies was conducted following the PRISMA 2020 guidelines in the PubMed and SCOPUS academic databases using the following keywords and Boolean operators (“cracked tooth” OR “cracked tooth syndrome” OR “tooth cracks” OR “dental cracks” OR “enamel cracks”) AND (diagnosis OR diagnostic OR detection OR imaging OR “diagnostic accuracy”). The search included studies published within the last 10 years, written in English, and with free full-text availability. Diagnostic test accuracy studies evaluating clinical or imaging methods for detecting dental cracks were included. Study selection, data extraction, and risk-of-bias assessment using the QUADAS-2 tool were performed independently by two reviewers. Owing to methodological heterogeneity, a qualitative synthesis of the evidence was undertaken. Results: The literature search identified 81 records, of which 12 studies met the eligibility criteria and were included in the systematic review. The evaluated diagnostic methods included visual examination, transillumination, quantitative light-induced fluorescence, cone-beam computed tomography, contrast-enhanced cone-beam computed tomography, optical coherence tomography, magnetic resonance imaging, and artificial intelligence-assisted image analysis. Considerable variability in diagnostic performance was observed among the evaluated methods. Optical coherence tomography demonstrated the highest diagnostic accuracy for detecting enamel and dentinal cracks, whereas contrast-enhanced cone-beam computed tomography improved crack detection compared with conventional cone-beam computed tomography. Conventional clinical methods remained useful as initial screening tools but showed limited diagnostic accuracy when used alone. Conclusions: No single diagnostic method demonstrated consistently high diagnostic accuracy for all types of dental cracks. Current evidence supports a multimodal diagnostic approach that combines conventional clinical examination with advanced imaging techniques when indicated to improve diagnostic reliability and facilitate treatment planning. However, the available evidence remains heterogeneous, highlighting the need for additional high-quality diagnostic test accuracy studies using standardized reference standards and reporting methods. Full article

This study extended a previously established intraoral scanning (IOS) and optical coherence tomography (OCT) dual-modality monitoring workflow for computer-aided design/computer-aided manufacturing (CAD/CAM) restorations to three additional crown material classes alongside a resin composite (RECO) reference. Four material classes were investigated ($n=8$ each): RECO, polymer-infiltrated ceramic network (PICN), lithium disilicate ceramic (LDSC), and zirconia-reinforced lithium silicate ceramic (ZLSC). Monolithic crowns were adhesively luted to standardized human molar abutment teeth and aged by cyclic loading (50500$\mathrm{N}$, 2$\mathrm{Hz}$, 37 2${}^{\circ }\mathrm{C}$, up to 1250000 cycles) in a mouth-motion simulator. IOS and handheld OCT were performed at baseline and after every 250000 cycles under phantom-head conditions; correspondence was assessed using Spearman’s rank correlation coefficient (exploratory, uncorrected for multiple comparisons). OCT consistently showed higher defect extents than IOS across all material classes and timepoints. While no significant IOS-OCT associations were found for RECO and the PICN, OCT detected full-thickness vertical subsurface damage propagation from the earliest timepoint in LDSC and ZLSC, with IOS-derived surface wear remaining markedly lower. Surface-based monitoring alone did not reliably reflect subsurface damage propagation, a dissociation most pronounced in the vertical dimension and silicate-based materials. Intraoral OCT may provide complementary, non-invasive subsurface information to support individualized recall scheduling and minimally invasive repair decisions. Full article

Background/Objectives: This review describes the advantages of new photonic-based approaches for assessing the activity of caries lesions. Many lesions have been arrested or are non-carious developmental defects, such as fluorosis, which do not require intervention. New methods are needed to assess lesion activity and avoid unnecessary removal of the tooth structure. Methods: At present, there are no reliable methods for assessing lesion activity in vivo. Nondestructive optical monitoring of lesion structure and the changes in light scattering that occur during drying offer the potential for lesion activity assessment during a single examination. Since optical diagnostic instruments exploit changes in the porosity and the permeability of the lesion, they have the potential to assess whether lesions are active and expanding or arrested and undergoing remineralization. Optical coherence tomography (OCT), Raman imaging and fluorescence loss, thermal and short-wavelength infrared (SWIR) reflectance measurements during lesion dehydration with forced air are presented. Results: Clinical studies have shown that optical coherence tomography is capable of showing distinct structural differences between active and arrested lesions on coronal and root surfaces. Differences in the kinetics of dehydration measured using reflectance measurements at SWIR wavelengths coincident with water absorption bands also show great potential. Conclusions: OCT and dehydration imaging at SWIR wavelengths have great potential for assessing lesion activity since they can also be used for caries screening, are safe for frequent monitoring and do not require the application of external agents. Full article

Background: Biofilm formation and associated tooth demineralization are key factors influencing the clinical performance of dental materials. Methods: This study compared the antibiofilm and demineralization preventive effects of two zinc-modified glass ionomer cements (Zn-GICs) with a conventional GIC. Disk-shaped specimens of Caredyne Restore (CR), ChemFil Rock (CFR), and Ketac Molar (KM) (n = 6) were evaluated in a multi-species biofilm model using an oral biofilm reactor. Early biofilm formation was analyzed by scanning electron microscopy (after 2 h and 4 h), bacterial accumulation and water-insoluble glucan (WIG) production were quantified (after 12 h). For demineralization assessment, restored human enamel and dentin specimens (n = 6) including an additional resin-based control group (Dura Seal, DS) were subjected to a 14-day biofilm challenge and lesion depth was measured using swept-source optical coherence tomography and confocal microscopy. Results: CR showed significantly lower bacterial accumulation and WIG production than the other materials (p < 0.05). CFR demonstrated lower bacterial levels than KM (p < 0.05), whereas no significant differences were observed between CFR and KM in WIG production (p > 0.05). CR produced the shallowest enamel and dentin lesions, whereas DS exhibited the deepest (p < 0.05); however, no statistically significant differences were observed between CFR and KM in lesion depth (p > 0.05). Conclusions: CR demonstrated superior biofilm suppression and reduced demineralization, whereas CFR showed limited differences compared with the conventional GIC. Full article

Objectives: This study aimed to determine whether surface wear, identified through the superimposition of intraoral scans (IOS), can predict subsurface damage progression detected by optical coherence tomography (OCT) during fatigue testing of computer-aided design/computer-aided manufacturing (CAD/CAM) composite crowns. Methods: Monolithic CAD/CAM composite crowns (Brilliant Crios; $n=8$) were adhesively luted to standardized prepared human teeth and artificially aged by cyclic loading in a mouth-motion simulator (50–500 N, 2 Hz, 37 °C). Under phantom-head condition, IOS (surface wear) and handheld swept-source (SS)-OCT (subsurface damage) were performed before loading and after every 250,000 cycles. OCT crack depth/width were normalized to local thickness and cusp-tip distance; correspondence between IOS- and OCT-derived metrics at each timepoint was assessed with Spearman’s rank correlation coefficient ($\rho$) to test whether surface wear can predict subsurface damage under the given conditions. Results: All specimens survived without catastrophic failure, and both modalities revealed progressive damage from the earliest observation interval. OCT consistently showed higher defect percentages and larger dispersion (e.g., mean vertical defects (25.47 ± 4.97)% OCT vs. (4.36 ± 0.91)% IOS at T1 and (66.79 ± 19.53)% OCT vs. (7.78 ± 3.19)% IOS at T5). Across all timepoints, no statistically significant associations between IOS and OCT were observed (p = 0.146 to 0.955). Conclusions: Within the limitations of this exploratory, single-material in vitro study, restricted to a CAD/CAM composite (Brilliant Crios), surface-based monitoring alone did not reliably reflect subsurface damage progression. Clinically, this suggests that surface wear assessment may underestimate subsurface fatigue damage. Intraoral OCT may provide complementary, non-invasive information alongside routine IOS for individualized monitoring, but its added value needs to be confirmed in larger studies and other CAD/CAM composite materials and additional restorative material classes. Full article

This study introduces a framework for estimating the optical scattering properties of thin-film phantoms using a custom-built Spectral-Domain Dental Optical Coherence Tomography (DEN-OCT) system operating within the 780–900 nm spectral range. The purpose of this work was to assess the performance of this system. The system exhibited high depth-resolved imaging performance with an axial resolution of approximately 16.30 µm, a signal-to-noise ratio of about 32.4 dB, and a 6 dB sensitivity roll-off depth near 2 mm, yielding an effective imaging range of 2.5 mm. Thin-film phantoms with controlled optical characteristics were fabricated and analyzed using Beer–Lambert and diffusion approximation models to evaluate attenuation behavior. Samples representing different tissue analogs demonstrated distinct scattering responses: one sample showed strong scattering similar to hard tissues, while the others exhibited lower scattering and higher transmission, resembling soft-tissue properties. Spectrophotometric measurements at 840 nm supported these trends through characteristic transmittance and reflectance profiles. While homogeneous samples conformed to analytical models, the highly scattering sample deviated due to structural non-uniformity, requiring Monte Carlo simulation to accurately describe photon transport. OCT A-scan analyses fitted with exponential decay models produced attenuation coefficients consistent with spectrophotometric data, confirming the dominance of scattering over absorption. The integration of OCT imaging, optical modeling, and Monte Carlo simulation establishes a reliable methodology for quantitative scattering estimation and demonstrates the potential of the developed DEN-OCT system for advanced dental and biomedical imaging applications. The innovation of this work lies in the integration of phantom-based optical calibration, multi-model scattering analysis, and depth-resolved OCT signal modeling, providing a validated pathway for quantitative parameter extraction in dental OCT applications. Full article

Background/Objectives: Differentiating initial from moderate non-cavitated occlusal caries using intraoral radiography is challenging. This in vitro study aimed to verify the ability of Optical Coherence Tomography (OCT) to discern the extent of demineralization in non-cavitated carious lesions and discriminate between the exact caries stages. Methods: In total, 110 extracted molars and premolars with occlusal caries were examined by two calibrated examiners using OCT and radiography. Histological sections stained with acid red were used as the reference standard. Diagnostic accuracy was calculated by comparing OCT- and radiograph-based diagnoses with the histologic reference standard. Results: OCT demonstrated superior sensitivity (0.83), specificity (0.76), and overall diagnostic accuracy (0.79) for distinguishing moderate from initial lesions, outperforming intraoral radiography, which achieved a sensitivity of 0.48, specificity of 0.84, and accuracy of 0.70. McNemar’s test showed a significant difference in sensitivity (p < 0.05), but not in specificity (p > 0.05), between the two diagnostic methods. Conclusions: These findings confirm that OCT can visualize caries progression with sufficient precision to distinguish between the initial and moderate lesion stages in an in vitro setting. Further validation in clinical trials is necessary to support OCT’s application for routine caries diagnosis. 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

The current study aimed to quantify the length progression of enamel microcracks (EMCs) after debonding metal and ceramic brackets, implementing OCT as a diagnostic tool. The secondary objectives included a three-dimensional assessment of EMC width and depth and the formation of new EMCs. OCT imaging was performed on 16 extracted human premolars before bonding and after debonding. Debonding was conducted with a universal Instron machine, with ARI values recorded. Additionally, 2D and 3D OCT images were employed to detect EMC formation and progression. Enface images quantified the length, width, and number of EMCs, and the length and width were analyzed using Image J (1.54f) and MATLAB (R2014b), respectively. Sagittal cross-sectional images were used for EMC depth analysis. A paired t-test showed significant differences in the length, width, and number of EMCs after debonding (p-value < 0.05), while the Wilcoxon non-parametric test indicated significant EMC depth changes (p-value < 0.05). No significant results were identified for the EMC number in ceramic brackets and EMC depth in metal brackets. Three-dimensional OCT imaging monitored existing EMCs at higher risk of progression and detected new EMCs following orthodontic bracket debonding. This study provides novel insights into EMC progression regarding the length, width, depth, and number after debonding. Full article

Background: Optical coherence tomography (OCT) is an emerging, radiation-free diagnostic tool in dentistry, providing high-resolution, real-time imaging of both hard and soft tissues, including periodontal areas, for more accurate postoperative evaluations. This study aims to investigate the efficacy of OCT on periodontal tissues in animals by comparing the healing effects of laser therapy with those of conventional surgical instruments. Methods: Six rabbits underwent periodontal surgery using a laser, scalpel, and punch to perform an apically positioned flap on the mandibular anterior incisors and to create a tongue ulcer on the dorsal surface of the tongue. Visual and OCT evaluations were conducted on days 1, 2, 3, 7, and 14. Results: In periodontal surgery, the laser exhibited slightly faster healing compared to other methods. In tongue ulcer formation, the scalpel and punch groups demonstrated slightly faster healing than that of the laser. However, both methods ultimately showed similar healing outcomes. Conclusions: In the dental field, OCT is emerging as a valuable tool for assessing healing, including early stages of healing, in periodontal therapy. Full article

The oral cavity’s soft and hard tissues create a conducive environment for microbial proliferation and biofilm development, facilitating the colonization of prosthodontic and implant materials such as titanium (Ti) and zirconia (Zr). This study aimed to compare the efficacy of conventional decontamination methodologies (i.e., chemical and mechanical, using 0.12% digluconate chlorhexidine (CHX) solution-treatment and airflow) to adjunctive laser-based interventions on Ti and Zr substrates inoculated with Staphylococcus (S.) aureus ATCC 25923. Additionally, this investigation sought to elucidate the impact of these treatments on temperature variations and surface integrity, analyzing the laser irradiation effects on these prevalent dental materials. Experimental configurations were delineated for both Ti and Zr samples across four groups: (1) a conventional treatment group (CV); (2) a photodynamic therapy group (PDT); (3) an Er:YAG laser treatment group (Er); (4) a combined PDT and Er:YAG treatment group (PDTEr). Also, a negative control group (C) that received no treatment was considered. The decontamination of the inoculated disc samples was evaluated by quantifying the microbial colonies in colony-forming units per milliliter (CFU/mL). Temperature variations on the surface of the samples were determined during laser treatments. Surface modifications were investigated using scanning electron microscopy (SEM) and optical coherence tomography (OCT). For statistical analysis, Fisher 95% confidence intervals, Hsu’s MCB method, and the Kruskal–Wallis test were applied. With regard to the 10⁵ CFU/mL of the negative control group, results indicated average values equal for each study group to (1) 2.66 CFU/mL for Ti and 2 CFU/mL for Zr for the CV group; (2) 0.33 CFU/mL for Ti and 1 CFU/mL for Zr for the PDT group; (3) 1.25 CFU/mL for Ti and 0 CFU/mL for Zr for the Er group; (4), and 0 CFU/mL for both Ti and Zr for the PDTEr group. Therefore, the combined PDT and Er:YAG treatment (PDTEr) and the singular PDT modality outperformed conventional decontamination methods in eradicating S. aureus biofilms from both Ti and Zr surfaces. Notably, the PDTEr regime achieved a comprehensive elimination of microbial colonies on treated substrates. Surface examination employing OCT demonstrated discernible alterations in the surface morphology of samples subjected to Er:YAG and combined PDT and Er:YAG treatments. Temperature checks during treatments showed no major changes, suggesting the applied laser methods are safe. In conclusion, PDTEr and PDT eliminated bacteria more effectively, but Zr surfaces were more resilient, making them better for microbe-controlling applications. Also, the study demonstrated that the (less costly but lower resolution) OCT method can replace SEM for such investigations. Full article

During orthodontic treatment, the early diagnosis of microscopic changes in soft and hard tissues, including periodontal tissue, is very important to prevent iatrogenic side effects like root resorption and periodontal diseases. Cervical periodontal tissue is the most critical area that reacts first to mal-habits or orthodontic forces, and it is also the place where bacteria deposits in the early stage of periodontal diseases. The early diagnosis of hard tissue changes, such as demineralization, is also very important in maintaining a patient’s health during orthodontic treatment. Many diagnostic devices, including radiographic equipment and intra-oral scanners, are helpful in diagnosing these problems, but have certain limitations in invasiveness and precision. The purpose of this study is to verify the possible utilities of non-invasive diagnostic devices in the orthodontic field that can compensate for these limitations. For this, non-invasive optical diagnostic devices, including optical coherence tomography and optical Doppler tomography, were used in vivo with animal and human examination for hard and soft tissues. These devices can provide real-time three-dimensional images at the histological scale. The results of this study verified these devices can be used in clinical practice during orthodontic treatment and introduced a new diagnostic paradigm differentiating microstructural changes in tissues in orthodontic diagnosis. Full article

Early caries diagnosis still challenges dentistry. Polarization-sensitive optical coherence tomography (PS-OCT) is promising to detect initial lesions non-invasively in depth-resolved cross-sectional visualization. PS-OCT with determined degree of polarization (DOP) imaging provides an intuitive demineralization contrast. The aim of this study is to evaluate the suitability of DOP-based PS-OCT imaging to monitor controlled de- and remineralization progression for the first time and to introduce it as a valid, non-destructive in vitro detection method. Twelve standardized bovine enamel specimens were divided in different groups and demineralized with hydrochloric acid (HCl) as well as partly remineralized with fluoride over a 14-day pH-cycling experiment. The specimens were stored in artificial saliva and sodium chloride (NaCl), respectively. Progress measurements with PS-OCT were made with polarization-sensitive en faceand B-scan mode for qualitative evaluation. The specimens demineralized in HCl showed the most pronounced surface change (lowest DOP) and the most significant increase in depolarization. Additional fluoride treatment and the storage in artificial saliva resulted in the opposite (highest DOP). Therefore, DOP-based PS-OCT imaging appears to be a valuable technique for visualization and monitoring of enamel demineralization and remineralization processes in vitro. However, these findings need to be confirmed in human teeth ex vivo or in situ. Full article

Dental caries on the crown’s surface is caused by the interaction of bacteria and carbohydrates, which then gradually alter the tooth’s structure. In addition, calculus is the root of periodontal disease. Optical coherence tomography (OCT) has been considered to be a promising tool for identifying dental caries; however, diagnosing dental caries in the early stage still remains challenging. In this study, we proposed an ultrahigh-resolution OCT (UHR-OCT) system with axial and transverse resolutions of 2.6 and 1.8 μm for differentiating the early-stage dental caries and calculus. The same teeth were also scanned by a conventional spectral-domain OCT (SD-OCT) system with an axial resolution of 7 μm. The results indicated that early-stage carious structures such as small cavities can be observed using UHR-OCT; however, the SD-OCT system with a lower resolution had difficulty identifying it. Moreover, the estimated surface roughness and the scattering coefficient of enamel were proposed for quantitatively differentiating the different stages of caries. Furthermore, the thickness of the calculus can be estimated from the UHR-OCT results. The results have demonstrated that UHR-OCT can detect caries and calculus in their early stages, showing that the proposed method for the quantitative evaluation of caries and calculus is potentially promising. Full article

Optical coherence tomography (OCT) is an emerging imaging tool in healthcare with common applications in ophthalmology for the detection of retinal diseases and in dentistry for the early detection of tooth decay. Speckle noise is ubiquitous in OCT images, which can hinder diagnosis by clinicians. In this paper, a region-based, deep learning framework for the detection of anomalies is proposed for OCT-acquired images. The core of the framework is Transformer-Enhanced Detection (TED), which includes attention gates (AGs) to ensure focus is placed on the foreground while identifying and removing noise artifacts as anomalies. TED was designed to detect the different types of anomalies commonly present in OCT images for diagnostic purposes and thus aid clinical interpretation. Extensive quantitative evaluations were performed to measure the performance of TED against current, widely known, deep learning detection algorithms. Three different datasets were tested: two dental and one CT (hosting scans of lung nodules, livers, etc.). The results showed that the approach verifiably detected tooth decay and numerous lesions across two modalities, achieving superior performance compared to several well-known algorithms. The proposed method improved the accuracy of detection by 16–22% and the Intersection over Union (IOU) by 10% for both dentistry datasets. For the CT dataset, the performance metrics were similarly improved by 9% and 20%, respectively. Full article