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This study investigated two artificial intelligence (AI) methods for automatically classifying dental implant diameter and length based on periapical radiographs. The first method, deep learning (DL), involved utilizing the pre-trained VGG16 model and adjusting the fine-tuning degree to analyze image data obtained from periapical radiographs. The second method, clustering analysis, was accomplished by analyzing the implant-specific feature vector derived from three key points coordinates of the dental implant using the k-means++ algorithm and adjusting the weight of the feature vector. DL and clustering model classified dental implant size into nine groups. The performance metrics of AI models were accuracy, sensitivity, specificity, F1-score, positive predictive value, negative predictive value, and area under the receiver operating characteristic curve (AUC-ROC). The final DL model yielded performances above 0.994, 0.950, 0.994, 0.974, 0.952, 0.994, and 0.975, respectively, and the final clustering model yielded performances above 0.983, 0.900, 0.988, 0.923, 0.909, 0.988, and 0.947, respectively. When comparing the AI model before tuning and the final AI model, statistically significant performance improvements were observed in six out of nine groups for DL models and four out of nine groups for clustering models based on AUC-ROC. Two AI models showed reliable classification performances. For clinical applications, AI models require validation on various multicenter data., (© 2023. Springer Nature Limited.)

Aims: To evaluate screw loosening and fracture load and angular deviation of a single implant-supported prosthesis under multi-directional loading condition at three different occlusal contact points., Methods: A total of 40 metal crowns were cemented to external connection implants and were embedded vertically and obliquely. The occlusal surface of the crown was designed with three flat surfaces, contact a, b, and c, representing outer and inner 20-degree inclination for buccal and lingual cusps. The angular deviations of implant crown under static 50N of loading were measured. And screw removal torque was evaluated before and after 57,600 load cycles. Then, fracture load was measured for each specimen. Data analysis was performed using one-way analysis of variance test of significance followed by Tukey honest significant difference (HSD) test(p < 0.05)., Results: Angular deviation results showed statistical significance between all contact points in vertically embedded group compared to obliquely embedded group, which showed similar results between contact A and B compared to C. In the other hand, screw loosening evaluation did not show statistical significance among the tested groups. And for the fracture load evaluation the maximum values reached twice the yield values in all contact areas., Conclusions: Mechanical effects were different regarding to diverse loading direction and contact points. The results of this study suggest that the stress concentration might increase in unfavorable vector direction., (© 2023. The Author(s).)

Purpose: This study aimed to determine how the implant-analog-holder (IAH) offset, inner structure, and printing layer thickness influence the overall accuracy and local implant-analog positional changes of 3D printed dental models., Methods: Specimens in 12 experimental groups (8 specimens per group) with different IAH offsets, inner structures, and printing layer thicknesses were printed in three dimensions using an LCD printer (Phrozen Shuffle) and digitized by a laboratory scanner (Identica T500). The trueness and precision of the printed model as well as the angular distortion, depth deviation, and linear distortion of the implant analog were evaluated using three-way ANOVA., Results: The positional accuracy was significantly higher for IAH offsets of 0.04 mm and 0.06 mm than for one of 0.08 mm, for a hollow than a solid inner structure, and for a printing layer thickness of 100 µm than for one of 50 µm (all P<.001)., Conclusions: The accuracies of the 3D printed models and the implant-analog positions were significantly affected by the IAH offset, inner structure, and printing layer thickness., Clinical Significance: Given the observation of this study, premeditating the IAH offset of 0.06 mm, hollow inner structure, and printing layer thickness of 100 µm before printing can help clinicians reach the optimum overall printing accuracy and minimum the local positional changes of the implant-analogs., Competing Interests: Declaration of Competing Interest The authors have no conflicts of interest to declare. All of the authors have seen and agree with the contents of the manuscript, and there is no financial interest to report. We certify that the submission is original work and is not under review by any other publication., (Copyright © 2022. Published by Elsevier Ltd.)

In studies that assessed the accuracy of implant surgical guides, evaluations were based on the placement position of the implant by using a manufactured surgical guide. However, such assessments could involve errors that may occur during implant placement. Therefore, evaluating the 3-dimensional accuracy of the fabrication of the implant surgical guide itself is not enough. In the evaluation method described in this article, location-related information is obtained by connecting a scan body to the sleeve of the surgical guide instead of directly placing the implant. This helps to evaluate the accuracy of the surgical guide without errors in the placement of an implant., (Copyright © 2020 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

To simulate the current oral status of patients, including maxillofacial defects, the digital method described uses a method based on multisource data. These include data recorded from scans made with and without wearing an obturator and data obtained by scanning the surgical or interim obturator. This method eliminates the need for preliminary impressions and complex border-molding steps during the process of creating a definitive obturator, thereby greatly simplifying the fabrication process., (Copyright © 2019 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

During production of an immediate interim implant-supported fixed restoration with interim cylinders, the formation of an access hole in the dentures is critical. Traditional access hole formation involves repeated prosthesis insertion and removal in the oral cavity, primarily through trial and error, to adjust the hole position and size. The presented technique simulates the interim cylinder position based on the healing abutment position, enabling confirmation of the access hole position and ensuring more precise seating of the interim implant-supported fixed restoration., (Copyright © 2019 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Purpose: To determine the accuracy of a digital manufacturing method for dental implant restorations on stock abutments using intraoral scanners and prefabricated stock-abutment libraries., Materials and Methods: Two dental implants with internal hexagonal connections were placed in the mandibular second premolar and second molar areas of a partially edentulous dentoform model; stock abutments with a diameter of 5 mm, abutment height of 5.5 mm, and gingival cuff height of 2 mm were connected. The study model was scanned 10 times using a reference tabletop scanner and 5 types of intraoral scanners (IOSs). The data collected by 5 types of IOSs were divided into 3 groups, based on the type and matching of stock abutment library data: no library, optical library, and contact library groups. A total of 160 data files were analyzed, including reference data. The resulting data were used to evaluate trueness and precision., Results: Trueness and precision values in the group in which library data of the stock abutment were not used were 42.0 to 76.3 µm and 30.5 to 99.7 µm; corresponding values when the library data using an optical scanner were matched were 51.2 to 73.4 µm and 26.3 to 62.8 µm, and those when contact scanner library data were used were 30.1 to 62.4 µm and 15.5 to 55.9 µm. Thus, the accuracy of the contact library group was significantly higher than the accuracies of the no library (p < 0.001) and optical library groups (p < 0.001)., Conclusion: The application of prefabricated library data of stock abutments using a contact scanner improved the accuracy of scan data. Scan accuracy of the stock abutments differed significantly based on the type of scanner., (© 2019 by the American College of Prosthodontists.)

Purpose: To evaluate differences in implant placement accuracy depending upon the presence or absence of metal restorations, as well as between distal extension and tooth-end cases., Materials and Methods: Five experimental groups were designed with mandibular models exhibiting the following dental statuses: six anterior teeth and bilateral second molars, with bilaterally edentulous sites between them (group NN); six anterior teeth (group NDE); identical to group NN, with the six anterior teeth restored with metal crowns (group MN); identical to group NDE, with the six anterior teeth restored with metal crowns (group MDE); identical to group NN, with all remaining teeth restored with metal crowns (group MM). Six implants were placed on the bilateral first and second premolars and first molars; the linear and angular deviations between the preoperatively planned and actually placed implant positions were computed., Results: Implant position errors were 0.55 to 0.87 mm and 0.53 to 0.80 mm at the entry point and apex, respectively, and were 0.35 to 0.71 mm and 2.02 to 3.12 degrees in depth and angular deviations, respectively. Significant differences were observed between groups NN and MM in overall deviations at the entry point (P = .009) and apex (P = .026), as well as in depth deviation (P = .008)., Conclusion: The presence of metal restorations on all anterior and posterior remaining teeth resulted in significant differences in linear deviation at the entry point and apex between preoperatively planned and actually placed implant positions, compared with natural teeth without restorations. No significant differences were observed in placement accuracy between distal extension and tooth-end cases.

Objectives: The aim of this study was to evaluate the effect of anodized implants coated with combined rhBMP-2 and recombinant human vascular endothelial growth factors (rhVEGFs) on vertical bone regeneration in the marginal portion of the peri-implant., Study Design: Supra-alveolar defects were created in 3 male beagle dogs. Each animal received 8 implants that were either coated with a single growth factor (rhBMP-2) or combined growth factors (rhBMP-2 + rhVEGF), or an anodized implant (the control group). The amount of the vertical bone regeneration, the bone-implant contact, and the intrathread bone density were investigated using histomorphometric analysis at 8 weeks., Results: The bone morphogenetic protein (BMP) group and the BMP-VEGF group showed vertical alveolar bone regeneration and enhanced bone-implant contact in the microthread compared with the control group (P < .05)., Conclusions: Anodized implants coated with rhBMP-2 and rhBMP - 2 + rhVEGF can induce vertical alveolar bone regeneration, but the combined effect of rhBMP-2 and rhVEGF was not verified., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Purpose: To compare the load-bearing capacity after long-term use (5-year simulation) of posterior three-unit implant-supported fixed partial dentures (FPDs) fabricated with different esthetic materials.Materials and Methods: A total of 20 specimens fabricated from one design file using CAD/CAM were divided into four groups: polyetherketoneketone (PEKK) veneered with composite resin (CR); PEKK veneered with lithium disilicate (LD); zirconia veneered with fluorapatite (FA); and monolithic zirconia. Samples were placed into a chewing simulator with simultaneous thermocycling. The fracture load after aging was measured using the universal testing machine with load on the central fossa of the pontic.Results: FPDs fabricated with PEKK + LD had significantly higher fracture load (1,526.56 [SD 95.54] N) compared to PEKK + CR (1,069.54 [SD 67.94] N) (P < .05). FPDs fabricated with zirconia materials had significantly higher fracture load compared to PEKK materials (P < .05). There was no significant difference between monolithic zirconia and zirconia + FA (P > .05).Conclusion: FPDs fabricated with PEKK + LD were superior to PEKK + CR. These materials can be promising alternatives for use as implant-supported FPD materials in the high-stress-bearing posterior region. Zirconia + FA can be an alternative to monolithic zirconia in cases that require more esthetics. [ABSTRACT FROM AUTHOR]

De Souza AB, Papaspyridakos P, Weber HP, Vazouras K, Matarazzo F. Effect of dental implant therapy on the preservation of orofacial tissues: A systematic review and meta-analysis. Clin Oral Implants Res. 2023;34 Suppl 26:240-256. doi:10.1111/clr.14106. PMID: 37750525. No private or public funding was received for this research. The authors declare that they have no competing interests. Systematic review (with meta-analysis). [ABSTRACT FROM AUTHOR]

• Flapless surgery preserved more buccal bone in immediate implant placement based on CBCT data. • Clinical and aesthetic outcomes were underreported, limiting the assessment of clinical relevance. Pitman J, Christiaens V, Callens J, Glibert M, Seyssens L, Blanco J, Cosyn J. Immediate implant placement with flap or flapless surgery: A systematic review and meta-analysis. J Clin Periodontol. 2023 Jun;50(6):755-764. doi: 10.1111/jcpe.13795. Epub 2023 Mar 5. PMID: 36843361. The study was funded by the authors and their affiliated institutions. Systematic review with meta-analysis. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this pilot study was to evaluate and compare polyetherketoneketone (PEKK) with different framework materials for implant-supported prostheses by means of a three-dimensional finite element analysis (3D-FEA) based on cone beam computed tomography (CBCT) and computer-aided design (CAD) data.Materials and Methods: A geometric model that consisted of four maxillary implants supporting a prosthesis framework was constructed from CBCT and CAD data of a treated patient. Three different materials (zirconia, titanium, and PEKK) were selected, and their material properties were simulated using FEA software in the generated geometric model.Results: In the PEKK framework (ie, low elastic modulus) group, the stress transferred to the implant and simulated adjacent tissue was reduced when compressive stress was dominant, but increased when tensile stress was dominant.Conclusion: This study suggests that the shock-absorbing effects of a resilient implant-supported framework are limited in some areas and that rigid framework material shows a favorable stress distribution and safety of overall components of the prosthesis. [ABSTRACT FROM AUTHOR]

Featured Application: This study presents a strategy for operators to acquire more accurate digital impressions in single implant cases in terms of the orientation of the scan body and the scanning method. This study investigated the trueness of a digital implant impression according to the orientation of the implant scan body (ISB) and the scanning method. With the flat surface of the ISB facing either the buccal or proximal direction, the ISB was scanned using one tabletop scanner (T500) and three types of intraoral scanner (TRIOS 3, CS3600, and i500). The effects of differences in the scanning method and ISB orientation were assessed. Postalignment data were subsequently obtained with the abutments generated using a digital library, and superimposed with reference data using a best-fit algorithm, followed by root-mean-square error (RMSE) analysis. The RMSE was lower in the buccal groups (28.15 ± 8.87 μm, mean ± SD) than in the proximal groups (31.94 ± 8.95 μm, p = 0.031), and lower in the full-scan groups (27.92 ± 10.80 μm) than in the partial-scan groups (32.16 ± 6.35 μm, p = 0.016). When using the tabletop scanner, the trueness was higher when the ISB was connected buccally (14.34 ± 0.89 μm) than when it was connected proximally (29.35 ± 1.15 μm, p < 0.001). From the findings of this study it can be concluded that the operator should connect the ISB so that its flat surface faces the buccal direction, and attempt to scan all areas. Additionally, it is advantageous to connect an ISB buccally when using a tabletop scanner. [ABSTRACT FROM AUTHOR]

Featured Application: This paper's application of the proposed method is using a healing abutment to facilitate the accuracy of digital implant impression. The proposed method does not change the original impression process and additional material is not involved, which makes it easy to utilize. This study aimed to determine the influence of the healing abutment (HA), placed at the implant placement site, on the accuracy of intraoral scanning and buccal bite registration in quadrant maxillary and mandibular models when using three types of intraoral scanner (IOS) and elucidate the distribution of arch distortion. Six experimental groups based on whether the HA was connected and the location of missing teeth were digitized using one laboratory scanner (Identica T500) and three IOSs (Trios 3, CS3600, and i500). Three-way ANOVA was used to analyze the effects of the scanner, location and number of missing teeth, and HA using Tukey investigation analyses for multiple comparisons (α = 0.05). Linear distances between hemispheres from the upper and lower arches were analyzed using the Jonckheere–Terpstra trend test to investigate the tendency of distortion from anterior to posterior tooth positions (α = 0.05). The accuracy of IOSs in groups with HAs was found significantly more accurate than groups without HAs. There was a significant trend in distortion from anterior to posterior tooth positions when using the Trios 3 and i500 IOSs. The scanning accuracy was affected by the presence of an HA, and the distortion along with the arch span may vary with the IOS utilized. [ABSTRACT FROM AUTHOR]