Digital Scanning Research Articles

Evaluation of the use of different intraoral scanners for auricular prosthetic reconstruction

The use of intraoral optical scanners has been introduced for direct digital data acquisition in maxillofacial prosthetics, but their clinical accuracy has not been evaluated sufficiently. The purpose of this observational study was to evaluate the use of different intraoral scanners for extraoral maxillofacial digitization of an ear and to assess visually the clinical outcome of the generated 3-dimensional ear casts. A selected intact ear was scanned by using 3 different intraoral optical scanners: CEREC Primescan (Dentsply Sirona), Medit i700 (Medit Corp) and Panda P2 (Pengtum Technologies). Three-dimensional printed auricular casts were fabricated from the obtained scans, and a questionnaire administered to assess visually the clinical outcome of the generated casts. Comparisons between scanners were done by using the Kruskal-Wallis test followed by the post hoc test with Bonferroni correction when results were significant. The Wilcoxon Sign Rank test was used to compare the responses of both the prosthodontists and the lay personnel. All tests were 2-tailed (α=.05). The 3-dimensional printed auricular casts fabricated from the data acquired by using Primescan and Medit i700 scanners showed a statistically significant difference in matching scores when compared with the Panda P2 scanner (P<.001). Digital ear scanning with the Primescan and Medit i700 intraoral scanners should produce auricular prostheses that more closely match the normal ear when compared with those scanned by the Panda P2 scanner.

Unconfined compression behavior of basalt fiber–reinforced loess based on digital image correlation and scanning electron microscope

Unconfined compression behavior of basalt fiber–reinforced loess based on digital image correlation and scanning electron microscope

Soil burial degradation studies of photo‐crosslinked PCL‐PDMS‐PCL triblock copolymer films

AbstractThis article focuses on the soil burial degradation behavior of photo‐crosslinked Polycaprolactone (PCL) homopolymer and Polycaprolactone‐Polydimethylsiloxane‐Polycaprolactone (PCL‐PDMS‐PCL) triblock copolymer films. PCL homopolymer and PCL‐PDMS‐PCL triblock copolymer films with varying the chain length of PCL were synthesized. The microlevel, macrolevel, and structural changes in the samples of homopolymer and triblock copolymer were analyzed before and after soil burial test. Microlevel changes were determined by the evaluation of morphological properties with the digital camera, optical microscope (OM), and scanning electron microscope (SEM) images. These changes revealed that the degradation of copolymer films enhanced with increasing PCL chain length. The Macrolevel structural changes were examined by Fourier transform infrared spectroscopy (FTIR) and Differential Scanning Calorimetry (DSC) crystallinity. The soil burial degradation mechanism was proposed for PCL‐PDMS‐PCL triblock copolymer films based on the obtained results.

Characterizing orthodontic tooth movement in real time using dental monitoring scans: A pilot study.

This pilot study aimed to quantify the magnitude and type of tooth movement occurring in short time intervals within the regular monthly orthodontic visits for patients with fixed appliances and undergoing maxillary canine retraction. Additionally, this pilot study aimed to provide a descriptive evaluation for the accuracy and reliability of the Dental Monitoring (DM)-captured scans to those of an iTero digital scans in an extraction space closure model. 3D intraoral photographic scans (DM) for 12 patients with maxillary first premolar extractions in a single-centre academic institution. Twelve patients treated with fixed appliances and undergoing space closure for maxillary premolar extraction(s) were included. Nickel-titanium (200 g) closing coil springs were used for canine retraction. At initiation of space closure (T1), iTero scans were acquired, and patients were instructed to take DM scans every 4-5 days until their next visit in 4-5 weeks (T2). At T2, a final iTero scan in addition to a DM scan was taken. The number of patients who did the scans regularly as instructed declined as time elapsed. Stereolithography (STL) files generated from the DM scans were superimposed with the STL files from the iTero scans using GOM Inspect software to determine the accuracy of the DM 3D models. To assess rate, type and direction of tooth movement, each of the 3D image STL files generated from the DM scans, taken every 4-5 days by each patient, was superimposed on the previously captured scan. The rate of tooth movement for the maxillary molars and canines was calculated in the 3 planes of space (X, Y, Z) at each time point, until the end of the experiment. Preliminary results indicated that the maxillary canines appeared to be displaced the greatest amount in the first 4-5 days with initial distolateral movement. As time elapsed, the rate of tooth movement decreased, and the tooth started moving distolingually. Dental monitoring software provides a high-tech platform to monitor tooth movement in a 'real-time' approach. Accuracy of the photographic scans in relationship to the intraoral scans appears promising. There seems to be some evidence that the greatest amount of movement occurs initially in the first few days after activation, dropping thereafter to become a slower constant rate of tooth movement.

Implementing pharmacist-led diabetic digital retina scan services at a federally qualified health center

BackgroundDue to low national and local rates for annual eye exams in patients with diabetes, a pharmacist-led chronic care clinic creates a unique opportunity for pharmacists to provide digital retina scans in the primary care setting. ObjectivesThe primary objective is to assess the impact of a pharmacist-led digital retina scan service on rates of annual eye exams among patients with diabetes. Practice DescriptionKC CARE Health Center, a federally qualified health center in Kansas City, Missouri, offers healthcare services to any member of the community regardless of insurance status. Pharmacists work in this setting to assist with management of chronic disease under a collaborative practice agreement. Practice InnovationA pharmacist developed a workflow process to provide digital retina scans in the primary care setting for patients with diabetes who had not had an eye exam in the past 12 months. Images of each eye are captured using a RetinaVue 700 Imager and these images are submitted to an ophthalmologist for review. Evaluation MethodsRates of annual eye exams among patients with diabetes seen in the primary care clinic before and after retina scan service implementation were analyzed using a chi-squared test with an a-priori alpha of 0.05. Survey data of patient-reported barriers to follow-up were reported using descriptive statistics. ResultsThere was a 5% increase in the annual eye exam rate of patients with diabetes seen at the clinic during the study period. The increase in rate of annual eye exam from before the intervention to after was statistically significant (P < 0.001). ConclusionImplementing a pharmacist-led retina scan program in the primary care setting improved the rate of annual diabetic eye exams and demonstrated the benefit that pharmacists can have in enhancing accessibility to preventative care services.

Multi-Scale Decay Mechanism of Emulsified Asphalt Cold Recycled Mixture Under Freeze-Thaw

The road performance decay law of EACRM under freeze-thaw cycles was studied using laboratory tests on the macroscopic scale in order to comprehensively analyze the serious performance damage mechanism of emulsified asphalt cold recycled mixture (EACRM) in cold regions during the service period. The surface cracking behavior, internal void evolution characteristics, and asphalt mortar morphology damage of EACRM under freeze-thaw cycles were studied by means of digital speckle, industrial CT, and scanning electron microscope (SEM) on the mesoscopic and microscopic scale. The results show that along with the increase in the number of freeze-thaw cycles, the road performance of EACRM decreases significantly. The surface of EACRM obviously cracks, and the width and number of main cracks increase significantly. The fatigue times of the maximum horizontal strain in the whole field gradually decrease. Air voids and the average volume of meso-void visibly increase. The microcracks of cement-emulsified asphalt mortar constantly emerge at the interface. The serious damage of the “three-dimensional network structure” is the fundamental reason for the performance decay of EACRM in cold regions. The performance damage of EACRM in cold regions is aggravated by water seeping into voids from cracks. Eventually, EACRM shows serious freeze-thaw inflicted damage.

Three-dimensional configuration of crystal plasticity in stainless steel assessed by high resolution digital image correlation and confocal microscopy

In polycrystalline austenitic stainless steels, a comprehensive three-dimensional configuration of crystal plasticity in relation to microstructure is required to elucidate the deformation behaviors during mechanical loading. In the present work, a combination of backscattered electron image (BSE) based high-resolution digital image correlation (HR-DIC) and laser scanning confocal microscopy (LSCM) was employed to simultaneously investigate in-plane and out-of-plane deformations at the sub-grain scale in 316 stainless steel. The high spatial resolution and precise alignment provided by the three-dimensional deformation assessment enable the identification of specific slip and twinning systems. This is achieved through the minimization of the residual L2 norm between the in-plane components of experimental and theoretical strain tensors. Dominant slip and few mechanical twinning activities are initiated at the early-stage of yielding, and their frequency and intensity increase with the applied load. The hierarchical networks formed by nanotwins, along with the presence of grain and annealing twin boundaries, serve as obstacles for slip glide, leading to substantial twin–slip interaction and grain boundary strengthening. As a consequence of wide mechanical twins formed by parallel nanotwins coalescence and strain localization at the twin boundary, slip transmission occurs, resulting in an effective accommodation of external stress. Furthermore, the consistent observation of out-of-plane roughness, in alignment with twinning Burgers vector predictions, offers valuable insights into the significant deformation gradient occurring in the vicinity of boundaries. This deformation gradient is influenced by the neighboring mechanical twinning activities, indicating strong obstacle to twin transmission and high back-stresses resulting from the highly misoriented grain boundary.

Application of optical scanning systems and 3D modeling algorithms as a method to control the depth of teeth preparation for fixed orthopedic structures

Background. In orthopedic dentistry at the present stage of its development, a chemical technique for preparing teeth for fixed structures of dentures has been developed; however, the state of the pulp in response to preparation is not taken into account. As a result, medical tactics for preserving or extirpating the pulp of abutment teeth, depending on the clinical case, are unreasonable. Given the generally accepted rules for preparing teeth for fixed orthopedic structures, there is a significant percentage of complications. Controlling the depth of tooth preparation makes it possible to carry out this manipulation as rationally as possible, and as a result to ensure the effectiveness of procedure, based on the state of vitality of the prepared teeth. The aim of the study is to determine and control the depth of the studied teeth preparation using digital volumetric scanning technology and algorithms of a digital graphic 3D editor in the CAD/CAM system. Materials and methods. The article presents the results of using digital volumetric scanning of the CAD/CAM system and an integrated algorithm for digital 3D modeling to determine and control the depth of teeth preparation for fixed orthopedic structures. Results. Based on the results of digital volumetric scanning, the working thickness of the tooth preparation in the area of the tooth neck was determined with the formation of various types of chamfer in different study groups. In order to determine the depth of the preparation of hard dental tissues, an artificial crown was modeled in the CAD system — digital volumetric scanner NeWay (Open Technologies) and data on its thickness in the area of the ledge were obtained. Conclusions. Method of digital volumetric scanning to determine and control the depth of preparation of hard dental tissues makes it possible to prevent the development of irreversible morpho-functional changes in the tissues of teeth caused by odontoreparation.

Could various angulated implant depths affect the positional accuracy of digital impressions? An in vitro study.

The purpose of this in vitro investigation was to assess how implant depth could affect the three-dimensional positional accuracy of digital impressions made from angulated implants. Four modified maxillary models were printed and divided into four study groups. In each model, two angulated implant analogs were placed at the sites of the first premolar and first molar at four different depths of 1 (G1), 2 (G2), 3 (G3), and 4 (G4) mm from the models' edentate area. Scan bodies were connected to the analogs, and one operator made 10 full-arch scans for each master model using an intraoral scanner. Afterward, the marginal gingival part of all models was removed, and digital scans were performed for each model using a laboratory scanner to achieve a reference STL file as the control group. One-way ANOVA and Leven's tests were used to measure and compare the 3D distance deviations across research groups after the superimposing test and control scans. A significant difference between research groups was revealed by trueness and precision analysis (p<0.001). The trueness and precision results obtained for G1 and G4 were significantly better than those for G2 and G3 (p<0.05). This study demonstrated that implant depth could affect the digital implant impressions' 3D positional accuracy.

Future Practices of Breast Pathology Using Digital and Computational Pathology.

Pathology clinical practice has evolved by adopting technological advancements initially regarded as potentially disruptive, such as electron microscopy, immunohistochemistry, and genomic sequencing. Breast pathology has a critical role as a medical domain, where the patient's pathology diagnosis has significant implications for prognostication and treatment of diseases. The advent of digital and computational pathology has brought about significant advancements in the field, offering new possibilities for enhancing diagnostic accuracy and improving patient care. Digital slide scanning enables to conversion of glass slides into high-fidelity digital images, supporting the review of cases in a digital workflow. Digitization offers the capability to render specimen diagnoses, digital archival of patient specimens, collaboration, and telepathology. Integration of image analysis and machine learning-based systems layered atop the high-resolution digital images offers novel workflows to assist breast pathologists in their clinical, educational, and research endeavors. Decision support tools may improve the detection and classification of breast lesions and the quantification of immunohistochemical studies. Computational biomarkers may help to contribute to patient management or outcomes. Furthermore, using digital and computational pathology may increase standardization and quality assurance, especially in areas with high interobserver variability. This review explores the current landscape and possible future applications of digital and computational techniques in the field of breast pathology.

New-designed 3D printed surgical guide promotes the accuracy of endodontic microsurgery: a study of 14 upper anterior teeth

We aimed to design a novel three-dimensional (3D) printed surgical guide and evaluate its accuracy in assisting endodontic microsurgeries. A new 3D printed surgical guide was designed by computer-aided design and computer-aided manufacturing (CAD/CAM) technology and applied to 7 patients who underwent endodontic microsurgeries of upper anterior teeth from 2020.01 to 2020.12 as the experimental group. 7 patients who suffered from endodontic microsurgeries operated by the same surgeon without using the surgical guide from 2019.01 to 2019.12 were selected as the control group. Cone beam computed tomography (CBCT) was performed more than 12 months after operation, and the accuracy of apical resection was compared between the two groups. The accuracy of the microsurgery focused on the length and angle of the root apical resection. In the study, CBCT data and oral digital scanning data were used to reconstruct 3D models of periapical lesions with soft and hard tissue information, based on which we designed the new 3D printed surgical guides. The guides were successfully applied to the apectomy in endodontic microsurgeries. The deviation of the apical resection length of the experimental group (0.467 ± 0.146 mm) was better than that of the control group (1.743 ± 0.122 mm) (P < 0.0001), and the deviation of the apical resection angle of the experimental group (9.711 ± 3.593°) was significantly less than that of the control group (22.400 ± 3.362°) (P < 0.0001). The 3D-printed surgical guide could effectively guide endodontic microsurgery and improve its accuracy by fixing both the position and the angle of apectomy. The new type of surgical guide could accurately localize the root apex and guide the apical resection.

Characterization of ductile damage and fracture behavior under shear reverse loading conditions

AbstractThis paper deals with experimental and numerical analysis of the ductile damage and fracture behavior undergoing biaxial non‐proportional shear reverse loading conditions. In the numerical analysis, an anisotropic cyclic plastic‐damage constitutive model is considered to characterize the damage and fracture behavior. Additionally, the change in the hardening rate is observed after shear reverse loading. Thus, a newly modified non‐hardening strain region method is introduced to capture the change in the hardening ratio between isotropic and kinematic hardening. Furthermore, the damage surface is assumed to translate in the direction of the damage strain increment. Hence, a softening law based on the damage strain is proposed. The modified constitutive model predicts macroscopic force‐displacement and microscopic evolution of plastic and damage behaviors under shear reverse loading with a tensile preload. Through digital image correlation technique and scanning electron microscopy, numerical results can be validated by experimental ones. Furthermore, scanning electron microscopy pictures also reveal different damage and fracture mechanisms on the micro‐level.

Shell-tempered ceramics: A case study of Western Tripolye kitchen ware in the Middle Dniester region

The studies described in this article are based on the detailed examination of pottery assemblages from five Ukrainian sites attributed to the Western Tripolye Culture. Selected fragments of pottery were initially analysed using digital and electronic scanning microscopes in order to identify mollusc shells used as temper in pottery. Petrographic analysis revealed the elemental composition and techniques used in the manufacture of the ceramics, along with the differences between individual vessels.All the data was subsequently implemented in conducted experiments concerning the production of shell temper and ceramic vessels. The features of the vessels (resistance to thermal shock and influence of shell temper on cooking or stored products) were tested. Cooking products for experiments were selected according to the archaeological evidence. The pottery fragments and vessels used during these experiments were subsequently subjected to organic residue analysis.

Comparative evaluation of accuracy, time and patient acceptance between intraoral scanner and conventional alginate impression technique – An invivo study

Orthodontists use various dental records such as dental models or casts for diagnosis and treatment planning which includes making of dental impressions and study casts. Conventional alginate impressions are challenging for the patients with extreme gag reflex, irritation &amp; discomfort. Recently 3D technology has led to development of scanning and digital models, but one major concern has been the accuracy. So this study was done to compare the accuracy, time and patient acceptance between intraoral scanner and conventional alginate impression technique. 15 patients were selected. Alginate impressions were made using zhermack neocolloid. The patients were subjected to digital scanning with Medit i500 intraoral scanner. Procedures were timed. After the impressions, each patient was asked to complete survey. Tooth width measurements were made using digital vernier caliper from stone models. In the second method digital images were measured using medit link software. Anterior and overall Bolton ratio was calculated to determine accuracy. Digital impressions are accurate and comparable to conventional impressions as tooth width measurements did not differ significantly. Conventional impression consumed more time. Patients preferred digital impressions.Intraoral scanners are accepted by patients and they have comparable accuracy and time efficient compared to conventional impression.

Validation of Digital Impressions' Accuracy Obtained Using Intraoral and Extraoral Scanners: A Systematic Review.

At present, the evidence regarding digital impressions' accuracy recorded by using digital scanners is lacking. This systematic review aimed to evaluate whether the type of scanning (intraoral/extraoral) affects the Accuracy of Digital Impressions. Two independent reviewers performed a systematic search in the database both electronically and manually (PubMed, Ebsco HOST, the Cochrane Library, and Google Scholar) for articles published from 1 January 2010 to 1 December 2022. This study was registered with the International Prospective Register of Systematic Reviews (PROSPERO CRD42020188765) and followed the PRISMA statement. The question in focus was as follows: Does the type of scanning (intraoral or extraoral) affect the accuracy of digital impression? A total of 449 papers were obtained by searching electronically and manually. In total, 15 complete-text papers qualified for assessment based on eligibility criteria. After reading the full-text articles, five studies were excluded. Ten studies were selected for the qualitative analysis. The qualitative data reported that the accuracy of both types of scanners (intraoral and extraoral) lies within the range of clinical acceptability. Nevertheless, the intraoral scanners seem to be more accurate when compared to the extraoral scanners for a partial arch situation. Scanning type affects the accuracy of the digital impression. Various factors influence the scanning ability. Intraoral scanners seem to be more accurate compared to extraoral scanners for a partial arch situation. More studies comparing the accuracy of the intraoral scanner and extraoral scanner for a complete arch scan and in an in vivo study setting are needed.

Digital twins for the automation of the heritage construction sector

The implementation of emerging technologies generates new possibility for the Architectural Engineering and Construction sector. Specifically, the study focuses on the applications of Digital Twins in the heritage construction sector, an area characterized by significant potentials and challenges in various research fields (e.g., energy, digital technology, citizen engagement, cultural aspects, management, etc.). Bibliographic and scientometric analyses enable the systematic categorization of the literature, analyzing a total of 133 scientific publication realized in the years 2001–2023. The bibliometric analysis outlines time evolution, geographical distribution, type, and disciplinary fields of the publications. Meanwhile, the scientometric research identifies co-occurrence networks of authors, keyworks, and research topics. Thank to these techniques, the following research topics on Digital Twins in the Built Heritage have been identified and clustered: (i) Digital Twins and 3D scanner techniques; (ii) Digital Twins and virtual reality; (iii) Digital Twins and Heritage Building Information Model (HBIM); and (iv) Digital Twins and Internet of Things (IoT). Each technique is critically discussed, highlighting applications, methods, limitations, and gaps in the literature. This analysis also paves the way for future research directions and potential solutions to enhance the automation in the heritage sector. Additionally, a glossary of essential disciplinary terms is provided to guide the understanding of individual definitions as they apply to heritage constructions. The primary challenges relate to accuracy, security, interoperability, and synchronization of data and technologies from various sources, requiring appropriate verification and validation methodologies, as well as tailored standards, protocols, interfaces, and regulations. Moreover, ethical considerations should underlie the utilization of digitally driven predictions that incorporate human-computer techniques, and human–robot interactions. This extends to the formulation of specific policies, and legislation. Only through this approach, the immense potential of digital technologies can emerge to create cross-cutting professions, interactive engagement techniques, and compatible preservation and management activities.

Virtual implant scan body switch by using computer-aided design programs avoiding the need of obtaining a new intraoral implant digital scan: A novel protocol.

The present manuscript describes a technique to virtually switch an implant scan body eliminating the need of obtaining a new intraoral implant digital scan. Implant scan bodies assist on transferring the 3-dimensional position of the implants into the virtual definitive implant cast. However, if a different implant part is desired during the designing procedures of the implant restoration such as selecting a different implant abutment of varying height, angulation, or manufacturer, a new intraoral implant digital scan with the specific implant scan body is required. This novel protocol aims to reduce possible complications that require capturing a new intraoral implant digital scan, facilitate prostheses design modifications after the obtention of the definitive intraoral implant digital scan, and to ease the manufacturing procedures. The novel technique may provide a solution for virtually switch implant scan bodies for fabricating implant-supported single crowns or short-span prostheses. Additional studies are needed before its clinical implementation.

Skin Perfusion After Hemostatic Net: An Anatomic and Radiologic Study in a Cadaver Model.

The hemostatic net is a recent technique initially developed to reduce the occurrence of postoperative hematomas following facelift procedures. Its applications have expanded to include skin redraping, deep plane fixation, and other areas beyond the face. However, no experimental study has investigated its effect on skin blood supply. The aim of this study was to analyze facial skin vascularization after applying a hemostatic net to fresh cadavers. Fourteen hemifaces from fresh adult cadavers were examined. The study model involved a deep plane facelift procedure with the use of a hemostatic net. The first step, involving 4 hemifaces, included dissections and two-/three-dimensional angiographies by digital microangiography and computed tomography scan, respectively. The purpose was to evaluate the influence of the hemostatic net on vascular perfusion. The second step involved a sequential dye perfusion study performed on 10 other hemifaces that underwent facelift procedures with the hemostatic net to determine its impact on skin perfusion. The anatomic and radiologic techniques enabled visualization of skin, and showed the arterial system reaching the subdermal vascular plexus and branching between the vascular territories, without interference from the net. The sequential dye perfusion study showed staining after injection in each facelift flap, with comparable coloration distributions before and after the application of the net. The hemostatic net did not affect the skin blood supply, correlating with no clinical increases in ischemia and necrosis rates in the facelift flap. This study provides additional evidence supporting the safety of the hemostatic net in clinical practice.

The bone shielding versus dual-zone concept in treating thin-walled fresh extraction sockets with immediate implant placement: Soft and hard tissue changes. A randomized clinical trial.

To evaluate the ridge alterations and esthetic outcome 1 year after immediate implant placement using the dual-zone (DZ) technique versus the bone shielding concept in patients with intact thin-walled sockets in the esthetic zone. This randomized clinical trial included 26 patients with nonrestorable maxillary teeth in the esthetic zone who were randomly assigned to two groups (n = 13 each) to receive immediate implants using either the bone shielding concept or DZ. Definitive restorations were delivered after 2 months. Pink esthetic scores (PESs), vertical soft tissue alterations, and bucco-palatal ridge dimensional changes were measured and assessed using intra-oral digital scans at baseline and 1 year post-procedure. Labial bone thickness was measured using cone beam computed tomography scans at baseline and after 1 year. The bone shielding group provided bucco-palatal ridge thickness stability after 1 year (9.43 mm) compared to baseline values (9.82 mm), while DZ showed a significant loss in the bucco-palatal ridge thickness after 1 year (7.83) compared to baseline values (9.49). No significant difference was reported in the baseline bucco-palatal ridge thickness between the two groups (p = 0.6). After 1 year, the bone shielding group demonstrated 0.38 mm ridge shrinkage which was statistically significant (p = 0.0002) compared to 1.67 mm ridge shrinkage in the DZ group. In addition, the average total PES in the bone shielding group was 12.04 versus 10.28 in the DZ group. No significant difference was reported in the mesial papilla length between the DZ and the bone shielding group after 1 year (p > 0.05). However, the midfacial gingival margin (p = 0.026) and distal papilla were significantly higher in the DZ group (p = 0.0025). There was no significant difference in the mean ± SD mm bone gain at the apical level between the two studied groups after 1 year (p = 0.06) showing 0.85 ± 0.23 and 0.64 ± 0.32 mm, respectively. However, the bone shielding concept showed a statistically significant more bone gain mm (p < 0.001) at the (0.56 ± 0.43) and crestal (0.03 ± 0.8) levels after 1 year compared to DZ which revealed 0.18 ± 0.5 and 0.38 ± 0.29 mm bone loss, respectively. The bone shielding concept might offer a reliable alternative for restoring thin-walled sockets by minimizing postextraction ridge dimensional alterations effect following immediate implant placement in the esthetic zone. Nevertheless, the study suffers from confounding bias since there are two systematic differences between the groups, the barrier membrane type, and the level of bone filling. "This clinical trial was not registered prior to participant recruitment and randomization." NCT05381467.

Conventional versus Digital Dental Impression Techniques: What Is the Future? An Umbrella Review

A prosthetic rehabilitation, whether supported by implants, teeth, or mucous membranes, must be functionally and aesthetically adequate, so it is essential that the oral structures are reproduced as accurately as possible. The purpose of this overview is to evaluate the accuracy, time of digital impressions, and patient preference compared to those of conventional high-precision in vivo impressions. This umbrella review was developed following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) statement and was registered in the PROSPERO systematic review registry. The search method and study selection were based on the PEO (Population–Exposure–Outcome) model, a modified version of the PICO model. Systematic reviews regarding the dental impression technique made using an intraoral scanner versus the analog impression technique made with high-precision impression materials were searched electronically up to 1 February 2023 among articles published in English, through numerous registries and databases, such as PROSPERO e, Scopus, MEDLINE/ PubMed, BioMed Central, and Cochrane Library. The records screened totaled 2942, but only 23 systematic reviews were included in this umbrella review. The Assessing the Methodological Quality of Systematic Reviews (AMSTAR) 2 tool was used to evaluate the quality assessment of the systematic reviews included in this umbrella review. Accuracy, time, and patient preference for digital impressions were compared with those of high-precision conventional impressions. A total of 23 systematic reviews were included in this umbrella review. From the analysis of this umbrella review, the data on the accuracy between the two methods of taking the impression are conflicting, especially as regards full-arch rehabilitations. However, the digital impression seems to be preferred over the analog one as regards time and patient preference. However, there is limited high-quality evidence available for studying conventional and digital implant impressions. The results obtained are limited to the type of review performed, and the type of studies included was limited by the settings and study designs. Furthermore, another important limitation highlighted was that the digital scanners analyzed in the various studies are not the same, and the number of missing teeth or implants inserted is not the same. More in vivo clinical studies and RCTs are needed to increase the level of evidence for impression procedures.