BMC Oral Health最新文献

Background: This retrospective cohort study, adhering to STROBE guidelines, compared the accuracy of maxillary positioning achieved with a patient-specific implant (PSI)-based hybrid workflow, which utilised a temporary intermediate splint to identify and remove posterior bony interferences before definitive splintless PSI fixation, to conventional splint-based positioning using stock titanium osteosynthesis plates in orthognathic surgery. Translational and rotational movement deviations from the virtual surgical plan were assessed.

Methods: Twenty-six patients who underwent non-segmental Le Fort I osteotomy between January 2020 and June 2023 were included. Eleven patients received the PSI-based hybrid workflow, while 15 patients underwent conventional splint-based positioning. Group allocation was based on the logistical feasibility of PSI planning and manufacturing rather than randomisation. Pre- and postoperative 3D images were superimposed using IPS® Case Designer software (KLS Martin) to quantify deviations in three translational and three rotational axes. Between-group comparisons were conducted using unpaired t-tests and two-way ANOVA, and correlations were assessed using Pearson's coefficient.

Results: The mean translational deviation was significantly lower in the PSI group compared to the control group (0.46 ± 0.33 mm vs 0.79 ± 0.58 mm; p = .0044), as was the mean rotational deviation (0.82° ± 0.91° vs 1.24° ± 0.85°; p = .0397). Significant differences were identified for vertical translation (p = .0162) and yaw rotation (p = .0205). Operating time did not differ significantly between groups (p = . 1739). In the PSI group, greater planned displacement showed a weak correlation with larger deviations, a relationship not observed in the control group.

Conclusions: The PSI-based hybrid workflow resulted in statistically greater positioning accuracy compared to conventional splint-based fixation. However, the absolute improvements (approximately 0.3 mm and 0.5°) were small, likely of limited clinical relevance, and were not associated with reduced operating times. Due to the retrospective, non-randomised design, small sample size, and use of a PSI-based hybrid protocol, these findings should be considered hypothesis-generating. Larger prospective studies evaluating fully splintless PSI workflows and patient-centred outcomes are recommended.

Clinical trial number: Not applicable.

Background: Accurate preoperative assessment of the spatial relationship between mandibular third molars (M3Ms) and the inferior alveolar canal (IAC) is essential to minimize the risk of nerve injury. While panoramic radiographs (PRs) are routinely used as a first-line modality, their two-dimensional nature limits diagnostic reliability, often necessitating confirmatory cone-beam computed tomography (CBCT).

Methods: We developed a dual-stream, transformer-enhanced multimodal (panoramic radiography + selected CBCT slices) deep learning framework designed as a clinician-in-the-loop system. The model jointly processes paired panoramic radiographs and operator-selected CBCT slices to simulate a realistic specialist consultation. Four widely used high-performance backbones (ConvNeXt, Swin Transformer, ResNet-50, and VGG16) were systematically evaluated on a dataset of 250 paired PR-CBCT cases. Model performance was assessed using F₁-score, precision, recall, and area under the ROC curve (AUC). Model interpretability was explored using SHAP-based explainability analysis.

Results: Among the evaluated architectures, the ConvNeXt-based model achieved the highest overall performance, with a macro F₁-score of 0.9478, precision of 0.9515, and recall of 0.9468. The learned embeddings showed good class separability, and explainability analyses highlighted anatomically meaningful regions consistent with established radiographic risk signs.

Conclusion: The proposed multimodal 2D framework demonstrates competitive and robust classification performance. By integrating expert slice selection with automated feature extraction, the model functions as a standardized decision-support tool, aimed at reducing diagnostic variability in complex boundary cases where visual interpretation alone may be subjective.

Ti-base abutments with angulated screw channel (ASC) designs have been developed to address the esthetic challenges associated with labial screw access in anterior implant-supported single crowns, as well as the ergonomic limitations caused by restricted mouth opening in posterior crowns. Despite their increasing clinical use, there is limited research evaluating the impact of this design on the fracture resistance of various monolithic restorative materials across different anatomical regions, particularly after aging. This study aims to investigate the effect of angled screw channel design on the fracture resistance of implant-supported single crown restorations made of different materials in different anatomical regions after long-term thermal aging. In the study, a total of 80 implant-supported single crown restorations were prepared and then divided into subgroups (n = 10) considering anatomical region (anterior/posterior), restoration material (monolithic zirconia/lithium disilicate), and screw channel design (straight 0^°/angled 20^°). Monolithic zirconia and lithium disilicate crowns were fabricated in the form of maxillary central incisors for anterior, and mandibular first molars for posterior specimens. After cementation on Ti-base abutments, the specimens were aged with 40,000 thermal cycles (5^°C/55^°C), and the fracture resistance of the crowns was subsequently determined using a universal testing machine under compressive loading. Fracture patterns were examined under a stereomicroscope. Three-way analysis of variance followed by a Bonferroni post hoc test was used in data analysis (α = 0.05). According to the results, anatomical region, restorative material, screw channel design, and the interactions between these variables had a significant effect on the fracture resistance of implant-supported single crown restorations (p < 0.001). The use of ASC design reduced the fracture resistance of the restoration material in all groups, regardless of anatomical region and material type (p < 0.001). In the anterior region, using the ASC design resulted in a statistically significant strength loss, which was similar across all materials. In the posterior region, although zirconia material showed significantly higher fracture strength than lithium disilicate, the strength loss was more pronounced. The fracture loads observed in all specimens remained within reported physiological bite force ranges under the present experimental conditions. In conclusion, although the ASC design offers clinical advantages for implant-supported restorations, its effect on reducing the mechanical strength of the restorative material should be taken into account in clinical practice. While the fracture loads observed in this study remained within physiological limits, further investigations under long-term and in vivo conditions are warranted.

Introduction: Dental caries is a common oral health problem globally, necessitating accurate and accessible diagnostic approaches. This study aimed to evaluate and compare the diagnostic accuracy of ChatGPT (AI-based assessment) and teledentistry with the clinical dental examination as the clinical reference standard for detecting dental caries.

Methodology: A diagnostic accuracy study was conducted on a sample of 40 tooth images, determined through power analysis. Standardized smartphone images were obtained and assessed independently using two approaches: ChatGPT-based analysis and teledentistry evaluation by dental professionals. The findings from both methods were compared to clinical examination results. Diagnostic performance was evaluated using sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, and area under the curve (AUC). Agreement with the clinical reference standard was assessed using Cohen's kappa coefficient, while the McNemar test was used to assess systematic differences between paired classifications.

Results: Teledentistry showed numerically higher diagnostic performance than ChatGPT across all evaluated parameters. It achieved higher sensitivity (89.5% vs. 78.9%), specificity (85.7% vs. 66.7%), PPV (85% vs. 68.2%), NPV (90% vs. 77.8%), and overall accuracy (87.5% vs. 72.5%). Additionally, teledentistry showed a higher AUC (0.876) compared to ChatGPT (0.728), suggesting better discriminative ability. Both methods showed no statistically significant differences from the clinical reference standard; however, ChatGPT exhibited greater inconsistency.

Conclusion: Teledentistry demonstrated higher diagnostic accuracy and agreement with the clinical reference standard than ChatGPT in this preliminary study and may serve as a reliable diagnostic adjunct, particularly in remote settings. However, further refinement and validation of AI-based tools such as ChatGPT are necessary to improve diagnostic performance, with future research focusing on optimizing image quality and expanding datasets to enhance AI reliability.

Background: Adequate peri-implant soft tissue thickness and keratinized mucosa width are crucial for implant health and aesthetics. Autogenous subepithelial connective tissue grafts (CTG) are the gold-standard for augmenting thin biotypes, but they require a second surgical site. This trial evaluated whether a human fascia lata allograft (FLA) or platelet-rich fibrin (PRF) membrane could comparably enhance peri-implant soft tissue phenotype and serve as less invasive alternatives of CTG.

Methods: Forty-five patients with a thin gingival phenotype (≤ 1 mm thickness) requiring upper anterior implant were randomly assigned to receive soft tissue augmentation with either (1) FLA allograft, (2) PRF membrane, or (3) CTG (control). Interventions were applied concurrently with implant placement in a standardized manner. Gingival thickness (GT) and keratinized tissue width (KTW) were measured at baseline and 6 months using transgingival probing and clinical indices. Labial bone thickness was assessed by cone-beam CT at implant placement and 6 months.

Results: Forty-five enrolled patients completed the study. All treatment modalities showed improvements in gingival and bone parameters, with the connective tissue graft consistently demonstrating the greatest gains. The median keratinized tissue width increased to 4.00 mm in the Connective Tissue Graft group, slightly higher than the Fascial Lata Allograft and Platelet-Rich Fibrin groups (3.75 mm). Gingival thickness showed significant increases in all groups, with the Connective Tissue Graft reaching 2.15 mm, followed by Fascia Lata Allograft (1.80 mm) and Platelet-Rich Fibrin (1.55 mm). Labial bone thickness also increased, with the Connective Tissue Graft achieving the highest mean value of 2.300 mm, and after 6 months, significant gains were observed in both this group (p = 0.032) and in the Platelet-Rich Fibrin group (p = 0.044), while Fascia Lata Allograft showed a smaller, non-significant increase.

Conclusions: Both fascia lata allograft (FLA) and PRF improved peri-implant soft tissue parameters, however the connective tissue graft (CTG) remains the gold standard for achieving the greatest thickness and best aesthetic results. FLA is a promising alternative that avoids a second surgical site with comparable outcomes, whereas PRF offers faster healing but lacks the volume necessary for significant tissue modification.

Background: The aim of the study was to compare the time required for complete removal of overextended root canal filling in lower premolar teeth using two different rotary file systems; ProTaper Universal Retreatment (PTUR) system, XP-endo Retreatment (XPER) system versus manual Hedstrom (H-Files).

Methods: Thirty-six extracted permanent mandibular premolars with single canal were set to a standard length of 19 mm and prepared beyond the apical foramen by 3 mm up to F2 file of the ProTaper Gold system. Overextended obturation was performed by a size (25/08) gutta-percha and AH-Plus sealer using cold lateral condensation technique. Teeth were left for 7 days to ensure complete setting of sealer, then divided into 3 groups (n = 12) according to the gutta-percha removal method (Group Ι: H-Files, Group ΙΙ: PTUR, Group ΙΙΙ: XPER (XP-endo Shaper (XPES) + XP-endo Finisher R (XPEF-R)). Time taken was recorded and statistically analyzed.

Results: The XPER technique showed a statistically significant reduction in the time taken to remove the overextended gutta-percha compared to H-files and PTUR groups (P < .05), with the XPER group showing the shortest time, followed by PTUR, and then H-files.

Conclusions: XPER technique was significantly faster in removing the experimentally overextended gutta-percha than H-files and PTUR files, demonstrating superior procedural time efficiency.

Background: Previous studies have reported differences in the prevalence of tooth agenesis according to sagittal skeletal discrepancies, while third molars have often not been considered. The aim of the present study was to investigate the association between third molar agenesis and sagittal skeletal discrepancies.

Methods: This cross-sectional study comprised 484 orthodontic patients. Pre-orthodontic lateral cephalometric radiographs were digitally analyzed using OnyxCeph³. SNA, SNB, and ANB angles were determined, and the skeletal classification based on ANB was performed as Class I, Class II, and Class III. In addition, sagittal jaw positions were classified as retrognathic, orthognathic, or prognathic. Third molar agenesis was evaluated on panoramic radiographs. The control group consisted exclusively of individuals with a complete permanent dentition of 32 teeth. Statistical analysis was performed at α = 0.05.

Results: A total 244 females and 240 males were included: 216 patients had skeletal Class I malocclusion, 201 had skeletal Class II malocclusion, and 67 had skeletal Class III malocclusion. A total of 117 patients had third molar agenesis. Patients with skeletal Class III malocclusion showed a higher prevalence of third molar agenesis (total) (p = 0.0086) and a higher prevalence of maxillary third molar agenesis (p = 0.0003). The number of missing third molars ranged from 1 to 4, and a statistically significant difference was observed, with patients with skeletal Class III malocclusion showing a higher number of missing third molars compared with patients with skeletal Class II malocclusion (p = 0.0309) and skeletal Class I malocclusion (p = 0.0432). Logistic regression analysis was performed, in which gender and age were included in the model as covariates showed that Skeletal class III malocclusion remained associated with third molar agenesis (p < 0.05).

Conclusion: Third molar agenesis was significantly more prevalent in patients with skeletal Class III malocclusion.

Background: Screw loosening and implant-abutment interface (IAI) are critical for the long-term success of implant-supported restorations. This study aimed to evaluate the effect of abutment manufacturing technique on reverse torque values and micro-gap measurements at the implant-abutment interface.

Methods: Thirty dental implant-abutment-crown complexes (Implance, Verdent, Turkey) were randomly allocated into three groups (n = 10 each) based on the abutment manufacturing technique: Group I-prefabricated titanium abutments (manufacturer-supplied, Implance, Verdent, Turkey; titanium grade 5); Group II-CAD-CAM-milled titanium abutments; Group III-3D-printed titanium abutments (Selective Laser Melting, SLM). All abutments featured an internal hexagonal connection with platform switching. All crown abutments were tightened to 25 Ncm and subjected to cyclic loading (100 N, 1.6 Hz, 250,000 cycles). Removal torque was measured before and after loading. Micro-gaps at the implant-abutment and abutment-screw interfaces were evaluated using scanning electron microscopy (SEM). Statistical analysis was performed using One-Way ANOVA with Tukey's Post Hoc test for reverse torque and the Kruskal-Wallis test for gap measurements (α = 0.05).

Results: After cyclic loading, the 3D-printed (SLM) abutments exhibited significantly higher reverse torque values (11.08 ± 0.11 Ncm) compared to CAD-CAM-milled abutments (6.40 ± 0.79 Ncm) (P < 0.001). Prefabricated abutments demonstrated the highest post-loading torque values (13.31 ± 0.31 Ncm). All intragroup comparisons showed statistically significant reductions from baseline (P < 0.0001). No significant difference was found in implant-abutment interface gaps among groups (P = 0.105).

Conclusion: Within the limitations of this study, prefabricated abutments demonstrated the highest reverse torque values after cyclic loading. 3D-printed abutments showed significantly greater resistance to torque loss compared to CAD-CAM-milled abutments, approaching the performance of prefabricated abutments. The implant-abutment fit was comparable across groups, suggesting that connection design may be more influential than manufacturing method for macroscopic fit. 3D-printed titanium abutments demonstrated significantly greater mechanical stability than CAD-CAM-milled abutments, approaching the performance of the gold-standard prefabricated abutments. This suggests that additive manufacturing may offer a clinically viable alternative to milling when both customization and mechanical integrity are required. However, clinical studies are needed to confirm these in vitro findings.

Background: Preterm prelabor rupture of membranes (PPROM) is a multifactorial obstetric complication that contributes significantly to neonatal morbidity and mortality. Recent evidence suggests that systemic inflammation and periodontal health are critical determinants in the etiology of PPROM. However, conventional predictive methods often fail to integrate multidomain data for early risk assessment. This study aimed to develop an ANN-based model to classify PPROM status by integrating hematological inflammatory markers, periodontal indices, and maternal behavioral factors.

Methods: A multilayer perceptron (MLP)-based artificial neural network (ANN) model was developed using data from 149 women (70 PPROM, 79 controls) and 24 input variables. Hematological parameters were derived from routine clinical blood tests obtained during late pregnancy or at hospital admission prior to delivery, while oral and periodontal indices were assessed within 24 h postpartum. Discriminative performance was evaluated using receiver operating characteristic (ROC) analysis (AUC, sensitivity, specificity), and mean squared error (MSE) was used as the training loss function.

Results: The ANN model demonstrated high predictive performance with an MSE of 0.049, an R² value of 0.82, and an average deviation rate of -0.003%. These results indicate strong internal accuracy and suggest potential for generalizability. The model successfully captured complex, nonlinear relationships among biological and behavioral variables influencing PPROM risk.

Conclusions: This study presents an interdisciplinary ANN framework integrating hematological, periodontal, and behavioral variables for delivery-period PPROM classification. The findings established in this study are characterized as associative given the postpartum collection of periodontal data, necessitating future prospective validation for clinical translation.