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Following implant placement, a soft tissue barrier will form at the healing abutment connection called peri-implant mucosa. The dimension of this anatomical structure seems to play a key role in maintaining long-term peri-implant and marginal bone level stability. In its early stages, soft tissue healing is a process involving many cellular and molecular events. Enamel matrix derivative (EMD) may improve and accelerate soft tissue wound healing and inflammatory resolution. In the present split-mouth randomized clinical trial, EMD was used to influence the early phase of soft tissue healing around dental implants placed with a single-stage approach into a completely healed ridge. A total of 60 implants were placed in 30 patients (2 implants per patient, one in the test group and one in the control group). In the test sites, EMD was administered around the healing abutment before soft tissues were sutured. Soft tissue healing index (HI) and secondary endpoints (clinical, radiographic, and patientreported outcomes) were measured. Better outcomes were recorded in patients receiving EMD for all parameters. The present results support the use of EMD to improve and accelerate soft tissue wound healing around implants. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the dimensional accuracy of implant impressions obtained using five different tray types and two techniques. Materials and Methods: A partially dentate maxillary Kennedy Class II model was created as a reference model through 3D printing. Then, implant analogs 4.3 mm in diameter were placed at the first premolar, first molar, and second molar sites. Five types of trays were used to create impressions: (1) metal stock trays, (2) plastic stock trays, (3) custom trays fabricated using liquid crystal display (LCD), (4) custom trays fabricated using fused deposition modeling (FDM), and (5) custom trays fabricated using urethane dimethacrylate (UDMA) resin. Open and closed tray techniques were also compared. In total, 150 impressions were obtained. The reference model and impressions were scanned using a laboratory scanner. Additionally, the positional and angular deviations of implants with different tray types and techniques were evaluated using the superimposition method. Results: There was no statistically significant difference (P > .05) between the impression accuracy with the different tray types and impression techniques. The angular deviations with plastic and UDMA trays were greater than those with metal, FDM, and LCD trays. Angular deviation at the second molar was greater when using closed plastic trays compared to open plastic trays. The highest and lowest positional deviations were observed at the first molar implant with an open plastic tray impression (mean ± SD of 62.46 ± 28.54 mm) and a closed LCD tray impression (36.59 ± 29.93 mm). The greatest angular deviation was observed with an open FDM tray impression at the first premolar implant (0.067 ± 0.024 degree), and the lowest angular deviation was observed with a closed metal stock tray impression at the second molar implant (0.039 ± 0.025 degree). Statistical differences were detected using the Mann-Whitney U test for paired groups and the Kruskal-Wallis test for groups with more than three comparisons (P > .05). Conclusions: Plastic and metal stock trays or conventional and 3D-printed custom trays can be used to obtain implant impressions for maxillary partially edentulous arches with similar dimensional accuracy. The five tray types and two techniques may be safely used to obtain impressions of partially edentulous maxillary arches with three implants. [ABSTRACT FROM AUTHOR]

Immediate full-arch loading is a highly complex and techniquesensitive procedure. Digital impression techniques aim to replace conventional analog systems to carry out dental treatments in a more predictive, safer, and less time-consuming way. This case report describes a patient with a guarded periodontal prognosis, who was rehabilitated with implant-supported fixed prostheses after full-mouth extractions. Immediate full-arch loading was performed by means of two digital impression systems: photogrammetric technology with PIC dental in the maxillary arch, and MedicalFit in the mandible. Immediate provisional prostheses in acrylic resin (polymethyl methacrylate) were milled and placed within 12 hours after implant placement surgeries. Both provisional structures fitted properly providing adequate esthetics and function. After the implant osseointegration period, final digital impressions were registered, and definitive zirconia full-arch implant-supported prostheses were delivered. The 24-month follow-up did not show biologic or mechanical complications. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the influence of a novel scanning strategy--using two new intraoral scanner devices with different operators--on the full-arch scanning accuracy for a dentate maxilla. Materials and Methods: Two scanning strategies, a test and a control strategy, were used to produce full-arch impressions of the dentate maxilla of a study patient. Two intraoral scanning (IOS) devices were used. Five expert operators performed a total of 40 scans. The scan time was recorded for each. A reference model was obtained from the patient's maxillary arch with an analog impression. The model was later scanned with a highprecision laboratory scanner to create a digital reference model (DRM). The scanning accuracy was analyzed with 3D-analysis software using a root mean square (RMS) calculation method, and qualitative analysis was executed using machine learning software. Results: The mean RMS result for the test strategy was 82.8 ± 16 µm compared to 81.5 ± 16 µm for the control strategy. The mean RMS results were 84.7 ± 15 µm for Primescan (PS) and 79.6 ± 17 µm for 3Shape (3S). As such, the scanning strategies and IOS devices did not influence the scanning accuracy. Yet, a significant difference was found when the two strategies' scanning times were compared (P = .001), as well as the IOS devices (P = .001). The operator was found to have no influence on the scanning strategy. Conclusions: The accuracy of digital impressions is not influenced by different strategies, devices, or operators, in contrast with the scanning time, which is influenced by both strategies and devices. [ABSTRACT FROM AUTHOR]

Purpose: To compare the 3D accuracy of three scanning strategies and conventional impressions using an edentulous model with six implants. Materials and Methods: An edentulous maxillary master model was fabricated with six equigingival internal connection implants at 0 degrees of angulation. Ten conventional open-tray splinted implant-level impressions were made and poured in stone. A master model and conventional casts were digitized with a reference scanner. Digital impressions were made by calibrated clinicians with a TRIOS 3 intraoral scanner ([IOS] 3Shape) according to three scanning strategies: DIG1 (occlusal-palatal-lingual), DIG2 (S-type motion from buccal to palatal), and DIG3 (scanning two half arches and connecting them at the midline). Each technique was repeated 10 times on the master model. Deviations from the STL datasets (N = 40) were compared to those of the reference master model using the Hexagon Metrology software system PC-DMIS CAD++. Linear distortions (dX, dY, dZ), global linear distortion (dR), and angular distortions (Absdθx, Absdθy) were calculated. Kruskal-Wallis test and mixed linear and logistic regression models were used to compare the original and binary distortion measures between the techniques. Results: The mean dR ranged from 91 μm (conventional method) to 183 μm (DIG1). The mean angular distortion ranged from 0.20 degrees (Absdθx for DIG2) to 0.69 degrees (Absdθy for DIG3). No scan pattern resulted in a more accurate reproduction in any of the measured parameters than the conventional impression method. There were significant differences between the methods for all distortion measures. Conclusions: No group reproduced the 3D position of the six-implant master model below the thresholds for both global linear and angular distortions. All the digital strategies tested were less accurate than the conventional open-tray splinted implant-level impression technique. [ABSTRACT FROM AUTHOR]

ABSTRACT Background/Objectives Materials and Methods Results Conclusion The use of different models for the fabrication of custom‐fit mouthguards (MTGs) can affect their final thickness, adaptation, and shock‐absorption properties. This study aimed to evaluate the adaptation, thickness, and shock absorption of ethylene‐vinyl acetate (EVA) thermoplastic MTGs produced using conventional plaster or three‐dimensional (3D) printed models.A typical model with simulated soft gum tissue was used as the reference model to produce MTGs with the following two different protocols: plast‐MTG using a conventional impression and plaster model (n = 10) and 3DPr‐MTG using a digital scanning and 3D printed model (n = 10). A custom‐fit MTG was fabricated using EVA sheets (Bioart) plasticized over different models. The MTG thickness (mm), internal adaptation (mm) to the typodontic model, and voids in the area (mm2) between the two EVA layers were measured using cone‐beam computed tomography images and Mimics software (Materialize). The shock absorption of the MTG was measured using a strain‐gauge test with a pendulum impact at 30° with a steel ball over the typodont model with and without MTGs. Data were analyzed using one‐way analysis of variance with repeated measurements, followed by Tukey's post hoc tests.The 3DPr‐MTG showed better adaptation than that of the Plast‐MTG at the incisal/occlusal and lingual tooth surfaces (p < 0.001). The 3DPr‐MTG showed a thickness similar to that of the Plast‐MTG, irrespective of the measured location. MTGs produced using both model types significantly reduced the strain values during horizontal impact (3DPr‐MTG 86.2% and Plast‐MTG 87.0%) compared with the control group without MTG (p < 0.001).The MTGs showed the required standards regarding thickness, adaptation, and biomechanical performance, suggesting that the number and volume of voids had no significant impact on their functionality. Three‐dimensional printed models are a viable alternative for MTG production, providing better adaptation than the Plast‐MTG at the incisal/occlusal and lingual tooth surfaces and similar performance as the MTG produced with the conventional protocol. [ABSTRACT FROM AUTHOR]

A digital approach is described for fabricating a splinted framework and custom open tray for the impression of multiple implants based on a virtually created implant cast with the digital prediction of the future impression coping positions. In this technique, impression copings to be used in the definitive impression‐making process were digitally scanned and aligned to a preliminary cast using installed protective caps of screw‐retained abutments as references, which resulted in a virtual cast that offers information both about the impression coping positions and their surrounding tissues and could allow a splinted framework and custom open tray to be digitally designed and fabricated. Creation of a virtual cast through digital technologies eliminates the traditional manual splinted framework and custom tray fabrication procedures. Additionally, only one set of impression copings and analogs is needed in this technique, thereby reducing treatment time and cost. It also offers a splinted framework and custom open tray with consistent quality. [ABSTRACT FROM AUTHOR]

Objective: To determine the prevalence and severity of gag reflex at initial appointment of patients visiting the department of Prosthodontics using the Gag Severity Index (GSI) tool proposed by Fiske and Dickinson. Study Design: Cross-sectional study. Setting: Department of Prosthodontics, Islamabad Dental Hospital, Islamabad. Period: 1st November, 2022 to 31st April, 2023. Methods: All the patients who presented in outpatient (OPD) of Prosthodontics with 18 to 85 years of age were included in this study. All the data of age, gender, educational levels and gag severity grades were noted on a predesigned proforma. Percentages and frequencies were calculated for all the data by using SPSS version 22. Results: A total of 150 (55.14%) patients out of 272 who gagged, were included in the study, with 61 (40.66%) males and 89 (59.3%) females, the gag reflex being more prevalent in female patients. The patients’ age range was from 18 to 85 years. In terms of gag severity grades in 150 patients, grade I was observed in 60 patients (40.0%), grade II in 49 patients (32.7%), grade III in 30 patients (20.0%), grade IV in 10 patients (6.7%) and grade V in 1 patient (0.7%). 40.0% of grade I patients were from 18-40 years age group and 51.6% were from 61-85 years age group. 37.0% of grade II patients belong to 41-60 years of age. In terms of qualification, 40.6% exhibited hyper active gag reflex in patients with university level or above. Conclusion: Female patients exhibit a higher prevalence of gag reflex than male patients, with grade I being the most common. While a definitive solution is yet to be established, effective patient education and dentist diligence can lead to productive management and future treatment exploration. [ABSTRACT FROM AUTHOR]

OBJECTIVE To develop an innovative process for stereotactic brain biopsies in dogs and cats that would provide a definitive diagnosis and optimize the management of patients with brain lesions. ANIMALS 4 dogs and 1 cat diagnosed with 1 or more brain lesion(s) underwent brain biopsies between March 24, 2023, and October 25, 2023. METHODS Based on trajectories selected on images of MRI and CT scan performed on each patient, a computerized software program was used to design a 3-D–printed patient-specific device with maxillary dental impression located on a baseplate to secure the patient’s head and with insertion ports for the biopsy instrumentations located on a C-arm. As proof of concept, the device was successfully used in 2 cadavers before being used on clinical patients. All biopsy samples were submitted for histopathological examination. RESULTS Histological diagnosis was obtained in 80% (4/5) of the cases (choroid plexus tumor, astrocytoma, meningioma, and chronic meningoencephalitis of unknown origin). In 1 patient, the results of biopsy were nondiagnostic; postmortem diagnosis was consistent with a low-grade oligodendroglioma. All the patients were discharged within 24 hours after the procedure without complications. This novel stereotactic system allows the surgeon to perform safe, easyto-use, inexpensive, and minimally invasive precise brain biopsies in dogs and cats, without complications. CLINICAL RELEVANCE This unique technique could be applied to any size and type of skull and for any type of brain lesions and would provide diagnostic information that would be valuable for future treatment planning and prognosis. [ABSTRACT FROM AUTHOR]

In invisible orthodontics, the role of composite attachments in facilitating complex tooth movements is crucial. This study, which evaluates the efficacy of a novel clinical attachment procedure, holds significant implications for the field. The technique used two templates (one pre-drilled and the other pre-loaded with high-viscosity composites) and was compared with the standard procedure. Fifty attachments were planned for four dental arch prototypes. Dental impressions were taken using digital scans for virtual planning and after tested techniques. The stereolithographic files (STL) obtained were aligned with those of the virtual planning, and a colorimetric map was used to evaluate the composite resin's maximum excess and defect deviation. The enamel–resin interfaces were observed by scanning electron microscopy (SEM). The Fisher test for the distribution of detachments and morphological defects and the Mann–Whitney test for the maximum values of excess and defect were used. No significant results were found between groups for morphological defects and detachments, and the maximum values of defect and excess were reported. SEM images for the experimental technique showed integrated adhesion. This innovative procedure, which has proven reliable and operationally straightforward, holds promise, instilling confidence in its practicality and potential to advance the field of orthodontics. [ABSTRACT FROM AUTHOR]

Background: Many indices have been suggested to help orthodontists in predicting the ideal dental arch width. One of these was Pont's index which was established by Pont. He suggested equations to predict the ideal maxillary dental arch width (interpremolar and intermolar) from the combined mesiodistal width of the maxillary incisors. This study aimed to test the applicability of Pont's index as an orthodontic diagnostic tool in Egyptian population and to compare the results with those obtained from studies of different ethnic subjects. Methods: This study was performed using dental casts of 184 Egyptian individuals (82 males and 102 females; age range, 19–24 years). The casts were divided into 46 casts with normal occlusion, 46 casts with class I, 46 casts with class II and 46 casts with class III malocclusion, according to Angle's classification. Alginate impressions were taken for all patients and poured immediately using dental plaster. The real models were transformed into digital models using three-dimensional laser scanner to allow digital model analysis. Predicted arch widths were calculated using Pont's equations. The predicted values were compared to the measured values. Results: Intra class correlation coefficient (ICC) (absolute agreement) between measured and predicted arch widths was determined. Poor absolute agreement was found between measured arch width values and the corresponding values calculated according to Pont's index. Conclusion: According to the results of this study, Pont's index is not a reliable method for predicting the ideal dental arch widths in Egyptian populations. [ABSTRACT FROM AUTHOR]

Introduction: Asymmetric electromyographic (EMG) activity during teeth clenching has been linked to cognitive impairment, as evaluated by the Spinnler-Tognoni matrices test, and to asymmetric pupil size (anisocoria). Anisocoria indicates an asymmetric Locus Coeruleus activity, leading to an asymmetric hemispheric excitability worsening cognitive performance. Bite splint wearing corrects EMG asymmetry, reduces anisocoria and improves cognitive performance. This study explores the possible effect of EMG asymmetry on oculomotor behavior during text reading. Methods: In subjects showing different degrees of EMG asymmetry during clenching, the number and duration of fixation periods during a reading task, performed under two different occlusal conditions were analyzed. The first lecture was executed with a dental impression (imprint) interposed between the dental arches (corrected condition) and the second one with the arches in direct contact (habitual condition), without clenching effort. The imprint reduced the EMG asymmetries during clenching. Results: In both occlusal conditions, total reading time correlated with duration of fixations, but not with their number. An inverse relation was observed between the number of fixations and their duration across individuals. Fixation frequency and duration were positively and negatively correlated with the amplitude of EMG asymmetry, respectively. Differently, total reading time was not related to the EMG asymmetry. When switching from the corrected to the habitual condition, an increase in the number of fixations and a reduction in their duration was observed, while total reading time could be either increased or decreased. An increased fixation frequency was observed in most of the subjects, while a reduced duration only among individuals with shorter reading times in habitual condition. Discussion: In the habitual condition, EMG asymmetry influences reading patterns (more saccades/shorter fixations, less saccades/longer fixations) in our sample. The changes in text reading behavior elicited by occlusal correction can be explained by assuming that occlusal disharmony negatively interferes with the reading task by increasing the number of saccades necessary for text scanning. This finding may also indicate an increased difficulty in processing of visual information. The potential involvement of trigeminal pathways in the relation between occlusal factors and oculomotor control is discussed. [ABSTRACT FROM AUTHOR]

Objective Materials and Methods Results Conclusions The SafetyCrown workflow facilitates the immediate restoration of posterior single sites with the one‐abutment/one‐time concept. This randomized clinical trial aimed to assess the direct effect of immediate restoration on dental patient‐reported outcomes (dPROs), feasibility, implant accuracy, and time.Participants with a single posterior edentulous site for late implant placement underwent optical impressions, shade selection, and cone beam computed tomography. After virtual treatment planning, they were randomized into the test group and the control group. For the test group, individual definitive hybrid abutments were prefabricated. The next step was a fully guided surgery with printed guides. After the implant was placed using guided surgery, the abutment was inserted. A chairside CAD/CAM workflow was used to provide the patient with a provisional restoration. Implants in the control group were left submerged to heal. Oral health‐related quality of life (OHRQoL) was assessed using the OHIP‐G14, and dPRO was measured using a 10‐item visual analog scale (VAS) questionnaire. Additional measurements of implant accuracy and time were performed. Follow‐up was performed 7 to 10 days after implant placement.Thirty‐nine participants with 45 restorations were included (test group: 23, control: 22). Immediate restoration was successful in 21 out of 23 implants (91.3%) in the test group. Both groups exhibited decreased OHRQoL without significant intergroup differences, while patient satisfaction was high overall. Test group participants perceived higher benefits and satisfaction with immediate loading than participants in the control group. Implant accuracy averaged 0.60 mm at the shoulder and 0.95 mm at the apex. Operative time was longer in the immediate loading group (61.9 min) than in the control group (32.1 min) (p < 0.001).Considering the limitations, the immediate restoration of late placed posterior implants using the described workflow proved feasible in 21 out of 23 cases. Both groups achieved high patient satisfaction with no differences in OHRQoL during the first week. Patients who received immediate loading rated the benefits very highly and were satisfied with the provisional restoration during the healing period. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this clinical study was to compare the accuracy of intraoral scan system (IOS) with prefabricated aids and stereophotogrammetry (SPG) compared with open tray implant impression (OI) for complete‐arch implant‐supported fixed dental prostheses (CIFDP). Materials and methods: Patients needing CIFDP were enrolled in this study. OI, reference standard, IOS with prefabricated aids, and SPG were performed for each patient. Distance and angle deviations between all pairs of abutment analogs, root mean square (RMS) errors between the aligned test and reference model, and chairside time were measured. The effect of inter‐abutment distance, jaw (maxilla or mandible), number of implants, and arch length on deviations was analyzed. The mixed effect model was applied to analyze deviations and RMS errors. Results: Fifteen consecutive individuals (6 females and 9 males, 47–77 years old) with 22 arches (9 upper and 13 lower jaws) and 115 implants were included. There was no significant difference in distance deviation comparing SPG and IOS with OI (p >.05). IOS showed a significantly greater angle deviation and RMS errors than SPG (median 0.40° vs. 0.31°, 69 μm vs. 45 μm, p <.01). The inter‐abutment distance was negatively correlated with the accuracy of SPG and IOS (p <.05). The chairside time for IOS, SPG, and OI was 10.49 ± 3.50, 14.71 ± 2.86, and 20.20 ± 3.01 min, respectively (p <.01). Conclusions: The accuracy of SPG and IOS with prefabricated aids was comparable. IOS was the most efficient workflow. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study was to compare the accuracy of full‐arch conventional implant impressions using two different materials (A‐silicone and polyether) to full‐arch digital implant impressions produced from two intraoral scanning devices. Materials and Methods: A master model was fabricated representing an edentulous mandible with four implants with internal connection placed at the sites of canines and first molars. The anterior implants were parallel to the residual ridge, while the two posterior implants had an angulation of 15° to the distal and 15° to the lingual respectively. The conventional technique was performed with open‐tray of non‐splinted impression copings. Two different impression materials were used, A‐silicone and polyether at monophase medium body consistencies. The digital impressions were obtained with the use of two different intraoral scanners, after the connection of scan bodies. A total of 10 impressions were produced for each of the four experimental groups. The conventional models as well as the master model were digitized using a high‐resolution laboratory scanner. The STL files of the models and of the intraoral impressions were imported in a powerful superimposition software, for the conduction of measurements in pairs of files. The software calculated the 3D deviations, as well as the linear and angular displacements among scan bodies at the digital files. For "trueness" measurements every STL file of each experimental group was superimposed to the digital master model, while for "precision" measurements all STL files of each experimental group were superimposed to each other. Results and Conclusions: The accuracy of full arch mandibular implant impressions was influenced both by the impression technique used (conventional vs. digital) and the impression material used (A‐silicone vs. polyether) or the intraoral scanner used (Trios vs. Heron).In terms of "trueness," A‐silicone showed the highest impression accuracy with the lowest deviation values, followed by polyether and Trios, but the differences between the three groups were in the majority not statistically significant. Heron showed statistically lower accuracy results in all measurements compared to the other groups.In terms of "precision", conventional impressions with the use of A‐Silicone or polyether were statistically significantly superior to digital impressions with either scanner. A‐Silicone and polyether showed no statistically significant difference between them. [ABSTRACT FROM AUTHOR]

Although dental patterns are unique, the use of bitemark analysis in personal identification remains controversial. To accurately reproduce and compare three-dimensional models of bitemarks and dental arches, intraoral three-dimensional scans, commonly utilized in clinical dental practice for precise and stable digital impressions, are recommended. This study aims to compare two different techniques for bitemark analysis: a digital method based on the superimposition of digital scans of dental patterns and lesions, and a visual method based on the physical superimposition of impressions and resin casts produced by 3D printing. A sample of 12 volunteers (6 males and 6 females) with a mean age of 26 years was collected as biters. Each subject was asked to bite on custom supports made from semi-rigid water bottles covered with imprintable dental wax. The dental arches and bitemarks were then recorded using an intraoral scanner and dental impressions. Scan superimposition analysis was conducted using CloudCompare software, while resin casts were printed using a 3D printer and physically superimposed on the bitemark impressions by a blind operator, who was not involved in sample collection, bite test execution, prior cast acquisition, or CloudCompare analysis. Both superimposition techniques relied on the selection of 10 corresponding landmarks (on canines and central and lateral incisors of the upper and lower arches) between the dental arches and impressions. The digital superimposition showed an average concordance of 92.5% for the upper arch landmarks and 85% for the lower arch landmarks, with an overall average concordance of 88.8% for both arches combined. In contrast, the visual analysis of resin casts showed an average concordance of 77.5% for the upper arch and 76.7% for the lower arch, with an overall average of 77.1% for both arches combined. In the analysis performed using CloudCompare, the maxillary arch demonstrated the best superimposition, with 4 landmarks (R0, R1, R2, R5) consistently overlapping. The digital analysis outperformed the visual analysis in all four quadrants, particularly in the upper right arch compared to the lower left arch, thereby supporting the integration of digital techniques in forensic applications. Further studies are necessary to validate the digital technique on a larger sample, including subjects with different dental characteristics, bite dynamics, and varying types of supports and substrates. [ABSTRACT FROM AUTHOR]

Background: The purpose of this pilot in-vitro study was to assess the effect of sterilization on the intra-implant axis, inter-implant axis, intra-implant distance and inter-implant distance of three implants in a straight line by using laboratory scanner (LBS) versus intra-oral scanner (IOS) with intra-oral scan bodies (ISB). Methods: A printed 3D model with three internal hex analogs in the positions 15#,16#,17# was used. Zirkonzhan (ZZ) intra-oral scan body (ISB), two-piece titanium was used. The ZZ ISBs were scanned by 7 Series dental wings (LBS) and 30 times by Primescan (IOS) pre sterilization and 30 times post sterilization. For each scan (pre and post) stereolithography (STL) file was created and a comparison between all the scans pre sterilization and post sterilization were superimposed on the laboratory scan by using a 3D analyzing software. A Kolmogorov-Smirnov test performed followed by Wilcoxon Signed Ranks tests. (p < 0.05) Results: Post sterilization of the ZZ ISB, the mean errors were significantly increased for the inter-implant distances (p < 0.0005), intra-implant distances 1,2,3 (p < 0.0005), intra-implant axis 1,3 (p < 0.0005) and inter-implant axes 13,23 (p < 0.05). In contrast, the mean errors for intra-implant axis 2 (p < 0.0005) and inter-implant axis 12 (p < 0.0005) were significantly reduced. Conclusions: ZZ ISB showed changes in all four parameters after sterilization. The middle ISB had the largest changes in mean error regarding all four parameters. Sterilization process may affect the three-dimensional (3D) structure of the ZZ ISB after three cycles. There is a lack in the literature in this field and there is a need for further studies to explore the effect of sterilization (multiple cycles) on different ISBs and for creating an approved guidelines regarding the amount of sterilization for each ISB in the industry. [ABSTRACT FROM AUTHOR]

Photogrammetry (PG) appeared as an alternative for multiple implant impressions. Stereo-photogrammetry is a more sophisticated alternative to PG, which estimates the 3D coordinates of the points of an object, making the process quicker and more precise. A search in PubMed MEDLINE, PMC, and Google Scholar was conducted to find systematic reviews published in the last 10 years. The PICdental® camera (IDITEC NORTH WEST, SL; Torrelodones, Spain) is a stereocamera that records implant positions in the mouth by means of photogrammetry with the objective of registering and obtaining a viable, reliable, and direct digital impression of the positions of the multiple implants. The use of photogrammetry via PiCdental® camera as an alternative to digital impression for multiple implants is an easy and trustworthy technique that permits an adequate fit without prosthetic complications. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the dimensional discrepancy between the diagnostic wax-up and the resulting mockup. Material and Methods: A maxillary model with misaligned teeth was scanned, and an initial cast was 3D printed. A total of 60 identical casts were 3D printed from the initial one after scanning. Based on a digital additive veneer wax-up on the six anterior teeth, 10 more casts were 3D printed. The specimens were allocated to seven groups (n = 10) as follows--group 1: transparent silicone matrix with a flowable light-cured composite resin; group 2: same as group 1 but with the addition of a prefabricated transparent tray; group 3: silicone impression putty (65 Shore A) and light-body silicone impression material with a dual-cured bisacryl resin; group 4: same as group 3 but without the light-body silicone; group 5: silicone laboratory putty (92 Shore A) with a dual-cured bisacryl resin; group 6: silicone laboratory putty (92 Shore A) with PMMA; group 7: wax-up casts (control). Scans from the mock-ups were coregistered, segmented, and superimposed with the scans from the wax-up. The difference between the mock-up and the wax-up was quantified by morphologic operations. Results were analyzed by Kruskal-Wallis test and Dunn post hoc test (P < .05). Results: All mock-ups were larger than the wax-up. Significant differences were found for every labial surface third. The incisal third was the least accurate third while the middle third the most accurate. The most accurate were groups 2 and 5, and the largest discrepancy was observed in group 6. Conclusions: The analog mock-up differs dimensionally from the wax-up, regardless of the technique/materials used. [ABSTRACT FROM AUTHOR]

Background: This clinical study aims to evaluate the accuracy of the conventional implant impression techniques compared to the digital impression ones in bilateral distal extension cases. Methods: A total of 32 implants were placed in eight patients missing all mandibular posterior teeth except the first premolars. Each patient received a total of four implants, with two implants placed on each side, in order to provide support for three units of screw-retained zirconia restorations. Following osteointegration, the same patient underwent two implant-level impression techniques: Conventional open-tray impressions CII (splinted pick-up) and digital implant impressions DII with TRIOS 3 Shape intraoral scanner. The accuracy of impressions was evaluated utilizing a three-dimensional superimposition analysis of standard tessellation language (STL) files. Subsequently, the scan bodies were segmented using Gom inspect software to measure three-dimensional deviations in a color-coding map. Data were statistically analyzed using the Kruskal Wallis test and then a post-hoc test to determine the significance level (P < 0.05). Results: The study revealed that higher angular and positional deviations were shown toward distal scan bodies compared to mesial ones for both impression techniques. However, this difference was not statistically significant (P > 0.05). Conclusion: Splinted open-tray conventional impression and intraoral scanning implant impression techniques have demonstrated comparable accuracy. Trial registration: Clinical Trials.gov Registration ID NCT05912725. Registered 22/06/ 2023- Retrospectively registered, https://register.clinicaltrials.gov. [ABSTRACT FROM AUTHOR]

Cleft lip and palate (CL/P) are a common congenital craniofacial anomaly requiring precise impressions for effective treatment. Conventional impressions (CIs) pose challenges in neonates with CL/P due to their delicate oral anatomy. While digital impressions (DIs) are increasingly recognised for their potential benefits over conventional methods in dentistry, their accuracy and application in neonates with cleft lip and palate (CL/P) remain underexplored. This study aimed to assess the accuracy of DIs compared to CIs in neonates with CL/P, using alginate and putty materials as references. A laboratory-based case–control study was conducted, utilising soft acrylic models resembling neonatal mouths with CL/P. Alginate and putty impressions were obtained conventionally, while digital impressions were captured using an intraoral scanner (IOS). A total of 42 models were analysed, divided evenly into three groups, with each group comprising 14 models. Superimposition and surface discrepancy analyses were performed to evaluate impression accuracy. The results revealed no statistically significant differences between the digital and conventional impressions in their intra-arch measurements and surface discrepancies. The mean measurement values did not significantly differ among groups, with p values indicating no significant variations (p > 0.05), confirmed by an analysis of variance. High intra-examiner reliability with Intra Class Coefficient (ICC) values close to 1 indicated consistent measurements over time. The current study demonstrates that DIs are equally accurate as conventional alginate and putty impressions in neonates with cleft lip and palate, offering a viable and less invasive alternative for clinical practise. This advancement holds promise for improving the treatment planning process and enhancing patient comfort, particularly in vulnerable neonatal populations. Further research is warranted to explore the clinical implications and factors affecting DI accuracy in this population. [ABSTRACT FROM AUTHOR]

Purpose: To determine the variation of OXIS contact areas in primary molars using digital impressions generated from an intraoral scanner (IOS). Methods: A cross-sectional study was carried out on 214 caries-free posterior quadrants of 80 children (38 males and 42 females) aged 3–6 years. Calibration of taking digital impressions with the IOS procedure was performed initially through scanning of ten quadrants of children to provide a learning environment to the examiner. The digital impressions were then exported, and the type of interproximal contact areas present between the distal surface of the primary first molar and the mesial surface of the primary second molar were identified according to the OXIS classification. The prevalence of the types of OXIS contact areas was expressed in the form of numbers and percentages. The chi-square test was applied to investigate the variability among the arches and to understand the association of OXIS contact areas across age, gender, and arches. Results: The most common contact area type observed was I-type (59.8%), followed by S-type (15.4%), X-type (12.6%), and O-type (12.2%). The I-type contact area was most frequently seen in both males (51.6%) and females (65.5%), while the S-type contact area in males (14.7%) and X-type contact area in females (8.4% each) were the least frequent with no statistical significance between genders (p > 0.05). All three age groups studied showed the highest prevalence of the I-type contact area, which increased with an increase in age (p < 0.05). The inter-arch comparison showed a significant result in terms of the X-type contact area on the right side, and O-type, X-type, and I-type contact areas on the left side, while no statistical difference was seen in the intra-arch comparison for all contact types. Conclusion: I-type contact areas were the most prevalent across the arches, age groups and genders. [ABSTRACT FROM AUTHOR]

In implantology, among the key choices, to obtain predictable results, it is essential to establish, using cone beam computed tomography (CBCT), the bone site and where to insert the implants; during the surgical phase, these sites must be identified on the oral mucosa. Surgical templates are a valid aid, especially in complex cases which require the insertion of more than three or four implants. In cases of a single implant, on the other hand, surgical guides are rarely used, and the implant is often inserted freehand; therefore, the identification of the implant site on the oral mucosa (after choosing the location on the CBCT) is more difficult. For this reason, the clinician uses the teeth in the arch as a reference. This study evaluates the ability of the human eye to identify, on the oral mucosa, where the implant collars will be positioned, the position of which has previously been chosen on the CBCT, in cases where the hands-free surgical technique (without surgical guides) is used. The verification of this precision is carried out using particular thermo-printed templates which contain radiopaque metal spheres. The results show that, in the freehand technique, it is difficult to precisely identify the implant sites (chosen via X-ray) on the mucosa, especially when they are far from natural teeth adjacent to the edentulous area. In case of monoedentulism, the freehand implant technique seems to be applicable by expert implantologists with a reduced risk of error; in fact, clinical experience helps to find the correct correspondence between the implant site chosen on the CBCT and its identification on the mucosa. The level of experience is fundamental in the clinician's decision about whether or not to use surgical guides; in fact, doctors with little experience should use surgical guides even in the simplest cases to reduce the risk of error. [ABSTRACT FROM AUTHOR]

Background: Since its introduction over two decades ago, the surgical laser has served in the lithotripsy of urinary calculi, resection of bladder tumours, bladder neck incisions, and prostate enucleation. Concerns regarding the safe use of holmium lasers have resulted in potentially excessive and overly precautious theatre regulations. We aimed to evaluate the preconceived impressions and practice patterns at a single site surrounding laser use in endourology. Methods: We designed a three-part online questionnaire that could be accessed using a smart device or computer. This survey was distributed to all theatre staff involved in laser surgery at our single site, including surgical, nursing, and anaesthetic staff of varying seniority. It asked questions regarding holmium laser safety, provided an up-to-date summary of published literature surrounding the safe use of lasers, and finally gave participants further option to alter the answers to several previously encountered questions. Results: A total of 54 theatre staff completed the survey, including 17 theatre nurses (31.5%), 10 urology consultants (18.5%), 8 urology registrars (14.8%), 7 anaesthetic registrars (13%), 4 anaesthetic consultants (7.4%). About 51.9% of participants believed that current laser safety protocols were adequate, with 38.9% finding them excessive. After reading recently published information on laser safety, 22.2% thought current laser safety measures were adequate (57% decrease) and 77.8% found them to be excessive (100% increase). About 74.1% of participants found that laser safety goggles impair their vision and that 79.6% would choose not to wear them if they were optional. Conclusion: Strict laser safety guidelines reflect an overestimated risk associated with using holmium laser in operating theatres. Laser safety regulations should be re-evaluated to align with current research and potential hazards inherent to the device. In doing so, a more effective distribution of staff could enable greater access to laser surgery, thereby reducing patient morbidity and hospital wait times. [ABSTRACT FROM AUTHOR]

Background: Dynamic navigation for implant placement is becoming popular under the concept of top-down treatment. The purpose of this study is to verify the accuracy of a dynamic navigation system for implant placement. Methods: Implant placement was performed on 38 patients using 50 implant fixtures. Patients in group C were treated using a conventional method, in which thermoplastic clips were fixed to the teeth, and patients in group M were treated using thermoplastic clips fixed to a mouthpiece attached to the teeth. The groups were compared to verify whether an accuracy difference existed. A treatment planning support program for dental implants was used to superimpose the postoperative computed tomography data on the preoperative implant design data to measure the entry point, apex point, and angular deviation. Results: The accuracy of group C was 1.36 ± 0.51 mm for entry point, 1.30 ± 0.59 mm for apex point, and 3.20 ± 0.74° for angular deviation. The accuracy of group M was 1.06 ± 0.31 mm for the entry point, 1.02 ± 0.30 mm for the apex point, and 2.91 ± 0.97° for angular deviation. Significant differences were observed in the entry and apex points between the two groups. Conclusions: The results indicate that group M exhibited better accuracy than group C, indicating that the stability of the thermoplastic clip is important for ensuring the accuracy of the dynamic navigation system. No previous studies have verified the accuracy of this system using the mouthpiece method, and additional data is required to confirm its accuracy for dental implant placement. The mouthpiece method improves the accuracy of implant placement and provides a safer implant treatment than the conventional method. Trial registration: University hospital Medical Information Network Clinical Trials Registry (UMIN-CTR), Registration Number: UMIN000051949, URL: https://center6.umin.ac.jp/cgi-open-bin/ctr%5fe/ctr%5fview%5fhis.cgi on August 21, 2023. [ABSTRACT FROM AUTHOR]

Purpose: Transoral robotic surgery is well established in the treatment paradigm of oropharyngeal pathology. The Versius Surgical System (CMR Surgical) is a robotic platform in clinical use in multiple specialities but is currently untested in the head and neck. This study utilises the IDEAL framework of surgical innovation to prospectively evaluate and report a first in human clinical experience and single centre case series of transoral robotic surgery (TORS) with Versius. Methods: Following IDEAL framework stages 1 and 2a, the study evaluated Versius to perform first in human TORS before transitioning from benign to malignant cases. Iterative adjustments were made to system setup, instrumentation, and technique, recorded in accordance with IDEAL recommendations. Evaluation criteria included successful procedure completion, setup time, operative time, complications, and subjective impressions. Further evaluation of the system to perform four-arm surgery was conducted. Results: 30 TORS procedures were successfully completed (15 benign, 15 malignant) without intraoperative complication or conversion to open surgery. Setup time significantly decreased over the study period. Instrumentation challenges were identified, urging the need for TORS-specific instruments. The study introduced four-arm surgery, showcasing Versius' unique capabilities, although limitations in distal access were observed. Conclusions: TORS is feasible with the Versius Surgical System. The development of TORS-specific instruments would benefit performance and wider adoption of the system. 4-arm surgery is possible however further evaluation is required. Multicentre evaluation (IDEAL stage 2b) is recommended. [ABSTRACT FROM AUTHOR]

The article investigates the dimensional stability of various three-dimensional (3D) printed models over a 21-week period, exploring the impact of different printing materials and storage conditions. Topics discussed include the observed shrinkage in all models regardless of material, the influence of exposure to daylight on shrinkage, and the comparison of shrinkage levels among different resin types.

Background: There is limited literature available comparing the accuracy of intraradicular impressions made with a novel hybrid impression material using the indirect and direct technique at three different locations. Materials and Methods: For this comparative in vitro analysis, postspace was prepared in 15 recently extracted teeth and impressions made with vinyl polysiloxane, polyether (PE), vinyl polyether silicone (VPES), and pattern resin. Postpatterns obtained were re-seated on the teeth and longitudinally sectioned.A binocular microscope was used to measure apical and lateral discrepancies at three locations (LI, L2, and L3). LI at the postcore junction, L2 at the middle of the post space, and L3, 2 mm short of the apical end. The data obtained were statistically analyzed using the Statistical Package for the Social Sciences (SPSS) software. One-way analysis of variance (ANOVA) (intergroup) followed by Tukey's post hoc test with P < 0.05 was used. Results: The one-way ANOVA noted a highly significant difference at the apical location. Pattern resin had the highest apical discrepancy (151.93 ± 8.59 µm), whereas the lowest was with vinyl PE silicone (140.31 ± 11.46 µm). At LI, the highest discrepancy was seen with pattern resin (32.09 ± 2.31 µm), whereas the lowest was with the addition silicone (31.94 ± 2.54 µm). At L2, addition silicone (32.88 ± 2.81 µm) showed the highest discrepancy, whereas the lowest was with vinyl PE silicone (30.5 ± 8.79 µm). The PE group had the highest mean at the L3 location (31.38 ± 3.46 µm) and the lowest was with vinyl PE silicone (30.93 ± 2.25 µm).At all lateral locations, no significant difference was noted. Tukey's post hoc comparison showed a significant difference between pattern resin and VPES (11.62 µm) followed by pattern resin and addition silicone (11.47 µm) apically. Conclusion: The indirect technique using VPES or addition silicone is more accurate than the direct technique at the apical location. [ABSTRACT FROM AUTHOR]

Introduction: Cleft lip‐palate is the most common craniofacial congenital anomaly. Patients with Cleft lip palate require treatment with a multidisciplinary approach from birth to enable independent feeding and physiological growth. In the past, the fabrication of therapeutic devices for a child with a cleft lip palate was executed through conventional dental impression materials , with the risk of suffocation. The use of a digital workflow minimizes impression‐related risks and streamlines procedures. Methods: This study aims to propose a hybrid workflow that can combine the advantages of digital workflow with the advantages of analog workflow that can be applied daily by clinicians treating cleft lip‐palate‐affected patients. Results: The device created was immediately accepted by the patient allowing autonomous nutrition. Evaluation of the effectiveness of the device was done by body weight assessment every 15 days. Conclusion: The patient had growth comparable to that of a child born healthy. [ABSTRACT FROM AUTHOR]

To evaluate the mechanical properties of a newly formulated vinyl polysiloxane (VPS) impression material. Materials and Methods: Experimental, Capture (S&C Polymer), Express, Imprint 3 and Imprint 4 (3M ESPE), Start VPS (Danville), Honigum (DMG), Virtual (Ivoclar Vivadent), Elite HD+ (Zhermack) were evaluated for tear strength, tensile strength, and elongation at break. Un-nicked specimens with a 90° angle on one side (type C) for tear strength were prepared and tested according to ASTM-D624. Dumbbell-shaped specimens (type 1) for tensile strength and elongation at break were prepared and tested according to ISO 37. All tests were carried out at 500 mm/min on a Shimadzu (AGS-X-10 KN-table top) tester. A one-way analysis of variance (ANOVA) was used to analyze the data. Results: Experimental material showed significantly higher or higher tear strength and elongation at break compared to other impression materials for both light body (LB) and heavy body (HB). For tensile strength, Experimental is similar to most impression materials; however, significantly lower than Imprint 3 and Start VPS for LB. This parameter for HB is higher or significantly higher than other impression materials except Start VPS. Tear strength and tensile strength were not correlated for LB but have a weak or moderate correlation for HB. Elongation at break is inversely proportional to tensile strength moderately for LB; however, there is no or very weak relation for HB. Conclusions: Experimental VPS impression material demonstrated a significantly higher tear strength and adequate tensile strength with higher elongation compared to other commercially available VPS impression materials. Adequate mechanical properties can provide accurate impressions for successful clinical fabrication of restorations. Experimental VPS impression material is suitable for use in dental impressions for fabrication of restorations. [ABSTRACT FROM AUTHOR]

Purpose: To compare the marginal gap and internal fit of fixed dental prostheses (FDPs) fabricated using intraoral vs extraoral scanning methods. Materials and Methods: MEDLINE/PubMed and the Cochrane database were searched. The focused PICO question was: For the fabrication of FDPs, does an intraoral scanning technique result in a different marginal gap than an extraoral scanning technique? The secondary outcome assessed was internal fit. Studies were selected based on the inclusion criteria, and a meta-analysis was performed. Results: A total of 14 studies (10 in vitro and 4 in vivo) were included in the meta-analysis. Marginal gap in single crowns was evaluated in 5 studies, copings for single crowns in 5 studies, three-unit FDPs in 3 studies, and both single-crown and three-unit FDPs in 1 study. Significantly lower marginal gap was found with intraoral scanning compared to impression scanning (P < .001) and cast scanning (P < .001), and for impression scanning compared to cast scanning (P = .037). Internal fit was superior with intraoral scanning compared to impression scanning, and this difference was significant (P < .001). No significant differences were found in internal fit with cast scanning compared to intraoral or impression scanning. The mean marginal gap/internal fit was 188.3 µm/146.2 µm with intraoral scanning, 116.29 µm/168.2 µm with impression scanning, and 195.1 µm/229.1 µm with cast scanning. Conclusion: Marginal gap was lower with intraoral scanning than with impression scanning and cast scanning. Impression scanning showed less marginal gap than cast scanning. Internal fit with intraoral scanning was superior to impression scanning, but when compared to cast scanning, no difference was found. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate intraoral scanners, scannable impression materials, and conventional methods for impression-taking with regard to precision and accuracy. Materials and Methods: Ten impressions per technique were initially taken from a cobalt-chromium (Co-Cr) master model (chamfer preparation for the maxillary right first molar) for fabricating Co-Cr crown copings. The test specimens, their respective metal master model, and the plaster casts from the conventional impressions were then digitized with the lightoptical Atos Triple Scanner. The fit of the dental crown copings was measured in two and three dimensions using computer-aided design software. Global differences between the methods were determined using Kruskal-Wallis test, and pairwise comparisons were performed with Mann-Whitney U test. The significance level was set at .05. Results: The 2D analysis showed that the average absolute marginal distance of the crown copings was 0.026 mm when fabricated with the digital impression method and 0.038 mm when fabricated with the conventional method (P = .028). However, the 3D analysis revealed that the conventional group had a smaller marginal gap (0.028 mm) compared to the digital group (0.06 mm; P = .015). Conclusion: This study showed that, in the field of single-crown prosthetics, digital impressions and the use of scannable impression material could serve as alternatives to conventional methods in the future. [ABSTRACT FROM AUTHOR]

Purpose: To summarize the evidence and determine the most effective impression technique for implant-supported prostheses in terms of accuracy, time efficiency, and patient preference in partially and completely edentulous arches. Materials and Methods: The searches were performed independently up to April 30, 2021 by two review authors through the Cochrane Oral Health Review, MEDLINE/PubMed, LILACS, and Science Direct databases. Moreover, manual and gray literature searches were performed to identify further potential reviews. Only English language--based systematic reviews with and without meta-analyses evaluating the different dental implant impression techniques were included. The outcomes assessed were accuracy, time efficiency, and patient preference. The methodologic quality of the included reviews was investigated by using the R-AMSTAR tool, and the degree of overlap of primary studies was assessed by calculating the percentage of corrected covered area (CCA) as proposed by Pieper et al.64 Results: The qualitative analysis included a total of 28 reviews, 8 of which included meta-analyses, published between 2008 and 2021, involving a total of 42 clinical trials and 203 laboratory studies. Digital vs conventional implant impression techniques were compared in 17 reviews, different digital impressions in 3 reviews, and different conventional impression techniques in the remaining reviews. Overall, the methodologic quality assessed by using the R-AMSTAR tool was moderate (mean: 26.7 ± 5.5) with slight overlap of primary studies (CCA; 5.23%). Conclusion: Within an overall moderate methodologic quality, the digital implant impressions showed favorable outcomes in terms of accuracy, time efficiency, and patient preference in partially edentulous arches involving three or fewer implants. However, the accuracy of full-arch digital impressions involving multiple implants is not satisfactory and needs significant improvements. Hence, future studies following stringent guidelines and robust methodology are recommended to substantiate the findings of this overview and provide a high level of evidence. [ABSTRACT FROM AUTHOR]

Abstract Background Various methods, chemical and physical, disinfect dental impressions. Common chemicals include 1% Sodium Hypochlorite and 2% glutaraldehyde, while UV radiation is a prevalent physical method. Few studies compare their effects on dimensional stability in polyether impressions. This study aims to assess such stability using different disinfection methods. Therefore, this study was planned to evaluate the dimensional stability of polyether impression material using different disinfection methods. Methods This in vitro study compared the effects of chemical disinfectants (1% Sodium Hypochlorite and 2% glutaraldehyde) and UV irradiation on the dimensional stability of polyether impression material. Groups A, B, C, and D, each with ten samples (N = 10), were studied. Group A was untreated (control). Group B was treated with 2% glutaraldehyde for 20 min, Group C with 1% Sodium Hypochlorite for 20 min, and Group D with UV rays for 20 min. A pilot milling machine drill was used to make four parallel holes labeled A, B, C, and D in the anterior and premolar regions from right to left. After sequential drilling, four implant analogs were positioned using a surveyor for accuracy. Ten open-tray polyether impressions were made and treated as described in the groups, followed by pouring the corresponding casts. Distortion values for each disinfection method were measured using a coordinate measuring machine capable of recording on the X- and Y-axes. Results A comprehensive analysis was conducted using the one-way ANOVA test for distinct groups labeled A, B, C, and D, revealing significant differences in the mean distances for X1, X2, X4, X5, and X6 among the groups, with p-values ranging from 0.001 to 0.000. However, no significant differences were observed in X3. Notably, mean distances for the Y variables exhibited substantial differences among the groups, emphasizing parameter variations, with p-values ranging from 0.000 to 0.033. The results compared the four groups using the one-way ANOVA test, revealing statistically significant distance differences for most X and Y variables, except for X3 and Y4. Similarly, post-hoc Tukey’s tests provided specific pairwise comparisons, underlining the distinctions between group C and the others in the mean and deviation distances for various variables on both the X- and Y-axes. Conclusions This study found that disinfection with 1% sodium hypochlorite or UV rays for 20 min maintained dimensional stability in polyether impressions.

Purpose: To compare the 3D accuracy of copy dentures fabricated using an IOS (IOS copy denture) to that of copy dentures fabricated using the conventional method (conventional copy denture). Materials and Methods: Maxillary and mandibular complete dentures were fabricated and scanned using a high-precision dental laboratory scanner to obtain data (basic data). Optical impressions of the dentures were recorded with the IOS to obtain data (IOS reference dentures). The IOS copy denture was fabricated using a 3D printer after configuring the data using the software. The conventional copy dentures were fabricated by making impressions of the complete dentures and pouring the room-temperature curing resin into them. The IOS copy dentures and conventional copy dentures were scanned using a high-precision dental laboratory scanner to obtain data. The data obtained were imported into 3D analysis software, and the IOS reference denture, IOS copy denture, and conventional copy denture data were each superimposed on the basic data for 3D evaluation by color mapping and calculation of the concordance rate. Results: Statistically significant differences in the concordance rates were observed between the IOS reference dentures and IOS copy dentures and between IOS copy dentures and conventional copy dentures (P < .05), but not between maxillary and mandibular complete dentures (P > .05). Conclusion: The IOS copy dentures demonstrated greater accuracy than the conventional copy dentures. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to evaluate the impression accuracy of two implants placed in different orientations and compare the impression accuracy obtained with the dual-arch impression technique using hybrid impression copings and the conventional open-tray impression technique. Materials and Methods: Five mandibular dentiform models were prepared by placing implants in the second premolar and second molar regions in the following different orientations: parallel to each other; 15-degree mesiodistal angulation; 30-degree mesiodistal angulation; 15-degree buccolingual angulation; and 30-degree buccolingual angulation. After making 10 impressions for each model with the open-tray impression technique and dual-arch impression technique with hybrid impression copings, cast models were fabricated for each impression (n = 10). Scan bodies were mounted on the five dentiform models and the fabricated 100 cast models were scanned using a desktop scanner. The three-dimensional deviation of the scan bodies on the cast models was calculated and compared to the reference data from the dentiform models. A two-way analysis of variance was conducted (α = .05). Results: The root mean square deviation values obtained from the implants placed with 30-degree mesiodistal angulation were 93.05 ± 6.21 µm with the open-tray impression technique and 104.01 ± 8.89 µm with the dual-arch impression technique, which were the largest deviation values for both techniques (P < .001). Compared to the open-tray impression technique, the dual-arch impression technique with the hybrid impression copings showed significantly lower accuracy when the angulation between the implants was 15 degrees mesiodistally (P < .001), 30 degrees mesiodistally (P = .016), or 30 degrees buccolingually (P < .001). However, there was no significant difference between the accuracy of the two impression techniques for parallel implants (P = .74). Conclusion: When the two implants were inclined 30 degrees mesiodistally, both implant impression techniques showed the largest deviation and the dual-arch impression technique showed lower accuracy compared to the conventional open-tray impression technique. Parallel placement of implants may improve impression accuracy and enable use of the dual-arch impression technique. [ABSTRACT FROM AUTHOR]

In the following narrative review, original articles and review articles were collected from Pubmed, LILACS, ScienceDirect, SciELO, Scopus, and Google Scholar in the period between January 2013 and August 2023. Were selected 32 open access type published articles, in Spanish and English. Digital and conventional impressions in children are compared according to time, precision, handling, comfort, and acceptance. According to the evaluation criteria, it is concluded from the literature that digital impressions are the preferred choice in children. Therefore, taking digital impressions is favorable in terms of time, precision, handling, comfort and acceptance over conventional impressions in children. [ABSTRACT FROM AUTHOR]

The reverse impression method involves the extraoral digitalization of the interim implant‐supported prostheses and intraoral digitalization of antagonist arch and maxillomandibular relationship. This technique allows the fabrication of implant‐supported prostheses by using a complete‐digital workflow. The scan analogs make the reverse impression method feasible. However, this method may not be recommended if the interim polymethyl methacrylate prosthesis does not have passive fit. The present manuscript describes an altered reverse impression technique that involves the extraoral digitalization of a conventional verification jig, which has attached scan analogs. With this technique modification, the implant positions captured using the verification jig are used to obtain the virtual definitive implant cast and fabricate the definitive implant‐supported prosthesis. [ABSTRACT FROM AUTHOR]

Purpose: Blunt bowel and/or mesenteric injury requiring surgery presents a diagnostic challenge. Although computed tomography (CT) imaging is standard following blunt trauma, findings can be nonspecific. Most studies have focused on the diagnostic value of CT findings in identifying significant bowel and/or mesenteric injury (sBMI). Some studies have described scoring systems to assist with diagnosis. Little attention, has been given to radiologist interpretation of CT scans. This study compared the discriminative ability of scoring systems (BIPS and RAPTOR) with radiologist interpretation in identifying sBMI. Methods: We conducted a retrospective chart review of trauma patients with suspected sBMI. CT images were reviewed in a blinded fashion to calculate BIPS and RAPTOR scores. Sensitivity and specificity were compared between BIPS, RAPTOR, and the admission CT report with respect to identifying sBMI. Results: One hundred sixty-two patients were identified, 72 (44%) underwent laparotomy and 43 (26.5%) had sBMI. Sensitivity and specificity were: BIPS 49% and 87%, AUC 0.75 (0.67–0.81), P < 0.001; RAPTOR 46% and 82%, AUC 0.72 (0.64–0.79), P < 0.001; radiologist impression 81% and 71%, AUC 0.82(0.75–0.87), P < 0.001. The discriminative ability of the radiologist impression was higher than RAPTOR (P = 0.04) but not BIPS (P = 0.13). There was not a difference between RAPTOR vs. BIPS (P = 0.55). Conclusion: Radiologist interpretation of the admission CT scan was discriminative of sBMI. Although surgical vigilance, including evaluation of the CT images and patient, remains fundamental to early diagnosis, the radiologist's impression of the CT scan can be used in clinical practice to simplify the approach to patients with abdominal trauma. [ABSTRACT FROM AUTHOR]

The impression materials utilized today in dental medicine offer a good reproducibility and are easily accepted by patients. However, because they are polymer-based, they have issues regarding their dimensional stability. In this respect, the present work proposes a new type of dental impression, which is reinforced with rigid mouthguards. The aim of the study is to test the performances of such new impressions by comparing them to conventional ones—from this critical point of view, of the dimensional stability. Three types of polymeric materials were considered for both types of impressions: alginate, condensation silicone, and addition silicone. In order to obtain the new type of impressions, a manufacturing technique was developed, comprising the following phases: (i) conventional impressions were made; (ii) a plaster model was duplicated, and 15 rigid mouthguards were obtained; (iii) they were inserted in the impression technique, with each mouthguard positioned on the cast before the high-consistency material was inserted in the tray and the practitioner took the impression; (iv) the mouthguard remained in the tray and the low-viscosity material was inserted over the mouthguard; (v) the impression was positioned on the model, and after the material hardened, the mouthguard-reinforced impression was analyzed. In the evaluation of the dimensional stability, rigorous statistical analysis was essential to discern the performance differences between conventional and mouthguard-reinforced dental impressions. Statistical analyses employed non-parametric Mann–Whitney U tests because of the non-normal distribution of the data. They indicated a statistically significant improvement in the dimensional stability of addition silicone impressions when reinforced with mouthguards (p < 0.05), showcasing superior performance over conventional methods. Conversely, alginate and condensation silicone reinforced impressions did not exhibit the same level of stability improvement, suggesting the need for further optimization of these materials. In conclusion, from the three considered elastomers, addition silicone was found to be the prime candidate for high-precision dental impressions, with the potential to improve their quality from conventional impressions by utilizing the proposed reinforcing technique. [ABSTRACT FROM AUTHOR]

Introduction:Various methods of identification such as anthropometry, stature estimation, dactylography, sex estimation, age estimation, DNA analysis, differentiation by blood groups and odontology are used in forensic medicine to create biological profile of an unknown individual. Estimation of sex is the first step towards identification of person. Determination of sex from skeletal remains is an essential task in medicolegal examination. Teeth are highly indestructible and reveal minimal turnover of natural substance hence teeth can be used for sex estimation.Mesiodistal parameter of mandibular and maxillary canine gave evidence of sex estimation due to sexual dimorphism. Aim: The aim of our study was to evaluate the sex estimation by mesiodistal width of mandibular canine and mesiodistal width of maxillary canine in north Indian population. Materials and Methods: The sample comprised of dental impression from 120 individuals (60 males and 60 females), all young adults between 20 and 35 years of age. Impressions of the teeth were made using irreversible hydrocolloid (alginate) material and casts poured in dental stone. Mesiodistal (MD) dimensions of mandibular and maxillary canine of both right and left side is measure by caliper. Results: Mean mandibular canine width of both right and left sidewere higher in male than female and were statistically significant whereas, mean maxillary canine width of both right and left side were slightly higher in male than female but were not statistically significant in young north Indian population. Left mandibular canine width (6%) was more sexually dimorphic than right mandibular canine width (5.1%). Whereas negligible sexual dimorphism shown by maxillary canine. Conclusion: The study confirmed that among maxillary and mandibular canine, mandibular canine can be used for sex estimation and shows significant sexual dimorphism. [ABSTRACT FROM AUTHOR]

(1) Background: Since new intraoral scanner (IOS) versions are introduced to the market and software continues to advance, there is an ongoing need to assess the accuracy of newer IOS models. (2) Methods: Four types of IOSs and one laboratory scanner (used as a reference) were used to scan an edentulous model with six parallel implants and their respective scan bodies, which were connected to each other. Using dedicated software, the distances between all scan bodies were calculated, generating a total of 540 measurements. Trueness (comparisons to the reference model) and precision (intragroup comparisons) were statistically compared with ANOVA and Tukey tests. (3) Results: When considering trueness values, statistically significant differences were observed between the tested scanner for all subgroups considered (p < 0.05). By contrast, no statistically significant differences were reported for precision values. (4) Conclusions: Within the limitations of the present in vitro study, it can be concluded that all tested IOSs were similar in terms of precision, while Trios and i700W yielded the worst trueness values. Nevertheless, increasing the measuring distance leads to a decrease in both trueness and precision. [ABSTRACT FROM AUTHOR]

Objectives: Limited studies are available on the accuracy of intraoral scanners (IOSs) for full‐arch implant and tooth models. This study aimed to assess the accuracy of maxillary full‐arch digital impressions of tooth and implant models made by two IOSs. Materials and Methods: This in vitro, experimental study was conducted on two maxillary dentiform models: one with six prepared natural teeth and the other with six implants at the site of canine, first premolar, and first molar teeth, bilaterally. A highly accurate industrial scanner was used for actual measurements on the models that served as the reference scan. TS (Trios3) and CO (CEREC Omnicam) IOSs were then used to scan each model 10 times according to the manufacturer's instructions. All scans were saved in STL format. The GOM Inspect software was used according to the best‐fit algorithm to compare the accuracy of measurements in the groups with the reference scan. The trueness and precision were calculated. Statistical analyses were carried out using SPSS by one‐way analysis of variance and t‐test (α =.05). Results: TS showed a significantly higher trueness than CO for both tooth and implant models (p <.05). TS also revealed significantly higher precision than CO for the tooth model; however, the difference in precision for the implant model was not significant between the two IOSs (p >.05). Conclusions: TS showed higher accuracy than CO in both tooth and implant models. [ABSTRACT FROM AUTHOR]

Background: Despite the updated guidelines on dental impression disinfection protocols during the COVID-19 pandemic, adherence to such procedures has not been studied among dental health professionals in Saudi Arabia. Understanding DHPs' knowledge, attitudes, and practices regarding COVID-19 is crucial in assessing a willingness to adhere to the recommendations provided by health authorities in mitigating the spread of COVID-19 via dental impressions impacting patient safety and infection control measures. Hence, this study aimed to assess dental health professionals' (DHPs) knowledge, attitudes, and practices (KAP) toward dental impression disinfection protocol during the COVID-19 pandemic in Saudi Arabia. Methods: A cross-sectional study using an online survey was conducted from 14 December 2022 to 21 March 2023 among practicing dentists, dental assistants (DA), dental laboratory technicians (DT), and dental hygienists in Saudi Arabia. A validated and reliable questionnaire that consisted of 38 items along with demographic variables was prepared to collect the data. Using Google Forms, a questionnaire link was prepared and shared on the social media platforms of DHPs in Saudi Arabia. A descriptive analysis was conducted to report the percentages and frequencies. The mean knowledge, attitude, and practice scores were analyzed using an Independent t-test, ANOVA, and Pearson's correlation tests. Results: A total of 718 DHPs voluntarily participated in the survey. Most of the DHPs exhibited average knowledge 392 (54.6%), neutral attitudes 393(54.7%), and adequate 549 (76.5%) practice towards dental impression disinfection protocol. The mean knowledge score differed significantly across nationality (p = 0.013), type of DHPs (p < 0.001), qualification (p = 0.045), and experience (p = 0.028) of the study participants. Significant differences in attitude towards impression disinfection were observed in different age groups (p = 0.002), qualifications (p = 0.015), and experiences (p = 0.024) of the DHPs. Similarly, practice varied across different age groups (p = 0.010), nationality (p = 0.013), type of DHPs (p = 0.019), qualification (p = 0.044), experience (p = 0.041), and COVID-19 Infection (p = 0.006). Moreover, a significant positive correlation between knowledge-attitude (r = 0.258, p < 0.01), knowledge-practice (r = 0.283, p < 0.01), and attitude-practice (r = 0.196, p < 0.01) was observed. Conclusion: DHPs considered in this study demonstrated average knowledge and attitudes toward impression disinfection, requiring improvement through continuous dental education and training. However, they displayed acceptable dental impression disinfection practices during the COVID-19 pandemic. It is highly recommended that continuing education programs should mainly reinforce the knowledge of sodium hypochlorite, iodophor, and phenolics and their concentrations to be used as an impression disinfectant. Additionally, it should focus on techniques of disinfecting elastomeric, hydrocolloid, zinc oxide and eugenol, and impression compound materials to mitigate the spread of COVID-19 based on Saudi ministry of health guidelines. [ABSTRACT FROM AUTHOR]

Introduction: Taking an ear impression is a minimally invasive procedure. A review of existing literature suggests that contactless methods of scanning the ear have not been developed. We proposed to establish a correlation between external ear features with the ear canal and with this proof of concept to develop a prototype and an algorithm for capturing and predicting ear canal information. Methods: We developed a novel prototype using structured light imaging to capture external images of the ear. Using a large database of existing ear impression images obtained by traditional methods, correlation analyses were carried out and established. A deep neural network was devised to build a predictive algorithm. Patients undergoing hearing aid evaluation undertook both methods of ear impression-taking. We evaluated their subjective feedback and determined if there was a close enough objective match between the images obtained from the impression techniques. Results: A prototype was developed and deployed for trial, and most participants were comfortable with this novel method of ear impression-taking. Partial matching of the ear canal could be obtained from the images taken, and the predictive algorithm applied for a few sample images was within good standard of error with proof of concept established. Discussion: Further studies are warranted to strengthen the predictive capabilities of the algorithm and determine optimal prototype imaging positions so that sufficient ear canal information can be obtained for three-dimensional printing. Ear impression-taking may then have the potential to be automated, with the possibility of same-day three-dimensional printing of the earmold to provide timely access. [ABSTRACT FROM AUTHOR]

Background: Full‐arch IOS scan of edentulous areas rehabilitated with dental implants is nowadays still described as an unpredictable procedure. To improve the accuracy, a universal scan template (UST®) is proposed in this article. The clinician can easily assemble the template with a mechanical coupling, by matching the scan bodies with objects of known dimension characterized by specific markers. The UST® facilitates the scanning of an entire arch on scan bodies, reducing the learning curve, simplifying acquisition movements, shortening the scanning time, and drastically reducing the risk of distortions and aberrations of the scans. Materials and Methods: In a case series study on 12 patients, the improvement in the accuracy of the scans with UST® was validated by comparing the STL files derived from scans with and without the guide in place. A titanium bar was produced from each optical impression. Results: The bars obtained from the optical impressions taken without UST® were found to be nonpassive in the mouth in the majority of the cases. On the contrary with the use of UST® we obtained 12 passive prosthetic rehabilitations. Conclusions: The proposed solution may represent a valid method to improve the predictability of full arch optical impressions on implants. [ABSTRACT FROM AUTHOR]

Objectives: To assess the trueness of digital measurements using direct and indirect scanning approaches compared to the actual clinical measurements. Materials and Methods: The crown length, width, and width/length ratio were measured in 36 anterior maxillary teeth using three different methods. The first was clinically using a digital caliper, the second was by scanning the teeth using a digital scanner and the third was by making an impression of the teeth, constructing a stone cast in the lab, and scanning it to obtain digital measurements. Bland–Altman test and intraclass correlation were used to assess the data and make comparisons. Results: Measurements taken using both approaches were highly reliable, with intraclass correlations ranging from 0.934 to 0.977 (p ≤ 0.000). Bland–Altman plot reflected a minimal mean difference between measurements especially in crown width measurements. Crown width/crown length measurement displayed the highest mean difference. Conclusions: Both direct and indirect optical surface scans showed similar high trueness in linear measurements of teeth. A higher discrepancy was detected in the crown width/length ratio. Clinical Significance: Digital dentistry is the new era in patient management. The use of conventional impression techniques and physical dental casts is associated with several disadvantages. Scanning dental casts to convert physical records into digital ones has multiple advantages. Optical surface scans (digital models) of the dentition are currently being more broadly used and advocated in the different dental disciplines including the construction of surgical guides for esthetic crown lengthening procedures. The trueness and reliability of linear measurements are of paramount importance to allow for proper fit and predictable outcomes. In this study, the trueness of these linear measurements obtained using direct and indirect methods was compared to the actual clinical measurements. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the comfort of children and adolescents with conventional full-arch dental impression methods compared to two intraoral scanners (iTeroTM and PrimescanTM). Methods: A monocentric, analytical, controlled crossover study was designed to compare conventional impression and digital impression with two intraoral scanners (iTeroTM and PrimescanTM) in children and teenagers. Patient comfort was evaluated using a 100 mm VAS scale adapted to Spanish and for children. A descriptive and analytical statistical method was conducted with a confidence level of 95% (p ≤ 0.05) and asymptotic or bilateral significance. Results: A total of 51 subjects were enrolled in the study (mean age = 12.35 years). Although the group of 10–14-year-olds was the most numerous, gender was equally distributed among the age groups. None of the variables on the VAS scale showed differences between the gender categories (p > 0.05). There were differences (p < 0.05) with respect to the age categories, as the middle adolescent group showed the worst general perception and total comfort during the conventional impression. Statistically significant differences were found between all VAS scale items and the three impression methods (p < 0.05). Conclusions: The digital impression technique is superior in terms of total comfort to the conventional alginate impression in children and adolescents. [ABSTRACT FROM AUTHOR]