Digital Impression Techniques Research Articles

Accuracy of digital and conventional implant-level impression techniques for maxillary full-arch screw-retained prosthesis: A crossover randomized trial.

This study aimed to compare the accuracy of implant-level conventional and digital impressions for atrophied maxillary ridges. Twelve participants with atrophied edentulous maxillary ridges received six implants. Six months later and after soft tissue maturation around healing abutments, a control cast was constructed using the final passive restoration for each patient. Two types of implant-level impression techniques were carried out for each patient: (1) conventional (splinted open-tray) impression technique and (2) digital impression technique. For both techniques, scan bodies were labeled from the most distal implant on the left side (A, B, C, D, E, and F) and scanning was made. Accuracy of both techniques was measured using in vitro (two-dimensional and three-dimensional) and in vivo (clinical) methods. Two-dimensional methods include measurement of the difference in linear distances AB, AC AD, AE, and AF. Geomagic software was used to assess the three-dimensional deviation between the two impression techniques using the superimposition of standard tessellation language files. The incidence and percentage of nonpassive frameworks and framework misfits of final restorations for both types of impression techniques were assessed using the single screw test. For all distances, digital impressions recorded significantly higher deviation from control measurements than conventional impressions. The highest two-dimensional linear deviation was noted for AF distance and the lowest difference was noted for AB distance. For all scan bodies, digital impressions recorded significantly higher three-dimensional deviation than conventional impressions. The highest three-dimensional deviation was noted with scan bodies C and D. Digital impressions recorded a significantly higher incidence of nonpassive frameworks and framework misfits than digital impressions. Within the limitations of this study, it could be concluded that the conventional implant-level impression technique showed greater in vitro and in vivo accuracy than the digital impression technique when used for full-arch maxillary fixed restorations on inclined implants.

Effect of different impression coping and scan body designs on the accuracy of conventional versus digital implant impressions: An in vitro study

ObjectivesThis in vitro study compared the accuracy of conventional versus digital impression techniques for angulated and straight implants using two different impression coping and scan body designs. MethodsTwo implant systems were used: Straumann and Dentegris. Two implants were placed for each system, straight and angulated at 15 degrees mesiodistally. Conventional impressions were made using the splinted open-tray technique using narrow impression coping (NIC) and wide impression coping (WIC). The stone casts produced from the conventional impression were digitized with a lab scanner (3Shape D2000). Digital impressions were made using four intraoral scanners (IOS): 3Shape Trios 3, Medit i700, Cerec Omnicam, and Emerald Planmeca using short scanbodies (SSB) and long scanbodies (LSB). The scanning was repeated ten times to generate the Standard Tessellation Language (STL) files. The distance and angle deviations between impression copings and scanbodies were measured in reference to the master model. ResultsThe trueness and precision of SSB and WIC were significantly better than LSB and NIC (p<0.001). The range trueness of the platform deviation was better with SSB (37.1 to 51.9) than LSB (89.6 to 127.9 μm) and for WIC than NIC in conventional impressions (58.2 and 75.1 μm, respectively). The trueness of the angle deviation of digital scans with SSB (0.11 to 0.25 degrees) was significantly better than scans with LSB (0.31 to 0.57 degrees) and for WIC than NIC (0.21 and 0.52 degrees, respectively). The precision of the platform deviation of digital scans with SSB (12.4 to 34.5 μm) was higher than other scans and conventional impressions (42.9 to 71.4 μm). The precision of the angle deviation of Medit i700 and Trios 3 with SSB (0.17 and 0.20 degrees, respectively) was higher than other scans with SSB and conventional impressions (0.54 to 1.63 degrees). ConclusionsDigital scans with SSB were more accurate than conventional splinted open-tray impressions. The type of impression coping and scanbody significantly affected the impression accuracy. Clinical significanceThe use of a short scanbody can increase the accuracy of digital impressions, and wide impression coping can increase the accuracy of conventional impressions, resulting in improved clinical outcomes.

Comparative Evaluation of the Marginal Adaptation of Emax Ceramic Inlays Fabricated Using Traditional Rubber Base and Digital Impression Technique in Permanent Premolar: An In Vitro Study

Comparative Evaluation of the Marginal Adaptation of Emax Ceramic Inlays Fabricated Using Traditional Rubber Base and Digital Impression Technique in Permanent Premolar: An In Vitro Study

Revolutionising conservative dentistry: Exploring the impact and evolution of digital impression techniques in contemporary dental practice

Digital dental impression technology has emerged as a transformative innovation in conservative dentistry, revolutionizing the process of obtaining accurate replicas of dental structures. This review explores the evolution, advantages, and implications of digital impression techniques in contemporary dental practice. From intraoral scanners to CAD/CAM technology and 3D printing, digital systems offer enhanced accuracy, efficiency, and patient comfort compared to conventional methods. Studies demonstrate the clinical acceptability and superiority of digital impressions for fabricating dental restorations and prosthetics, with reduced operation time and improved patient experience. The widespread adoption of digital technology heralds a new era in dentistry, promising streamlined workflows, superior restoration quality, and enhanced patient satisfaction. Embracing digital impression technology is essential for dental practitioners to remain at the forefront of modern dentistry and deliver optimal patient care.

Patient-reported outcome measures (PROMs) of digital and conventional impression methods for fixed dentures.

Digital impression technique or computer-aided impression (CAI) has been recently concluded as a clinically acceptable alternative to conventional impression method (CIM) in the fabrication of crowns, short fixed partial dentures (FPDs), and implant-supported crowns. The purpose of this study was to investigate the patients' opinion and subjective perception of two different ways of impression - digital and conventional. A total of 45 patients were treated with CAI and CIM for the fabrication of tooth or implant-supported crowns. They fulfilled a questionnaire including 11 questions regarding the treatment time, gag reflex, discomfort related to manipulation, and other aspects of treatment. CAI was considered the preferential method for future treatment in 53% of patients, whereas 28.9% of the respondents preferred CIM. The preference for the impression method was influenced by the total time spent with the procedure, discomfort during manipulation with the tray or scanning head, size of the tray or scanning head, maximal opening discomfort, and (the tendency towards) gag reflex. CAI was considered a more comfortable and preferential method. Discomfort or difficulties during CAI negatively affected the patients' attitude to CAI, whereas the difficulties associated with CIM did not have any influence on the preferred method.

Comparative Analysis of the Comfort of Children and Adolescents in Digital and Conventional Full-Arch Impression Methods: A Crossover Randomized Trial.

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. 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). The digital impression technique is superior in terms of total comfort to the conventional alginate impression in children and adolescents.

Comparative evaluation of the marginal fit of computer-aided design-computer aided manufacturing fabricated crowns from direct and indirect digital impression - A systematic review.

The accuracy of the digital impression method is responsible for fabricating crowns with adequate marginal fit which in turn determines the postendodontic prognosis. This systematic review was undertaken to identify the influence of the two digital impression techniques in producing full coverage crowns with better marginal fit. This systematic review was conducted according to the Preferred Reporting Items for Systematic Review and Meta-analysis statement. A detailed search was done in electronic databases (PubMed, EBSCOhost, LILACS, Cochrane) along with hand searches of reference articles. In vivo crossover studies comparing the marginal fit of the computer-aided design-computer-aided manufacturing (CAD-CAM) fabricated crowns from direct and indirect digital impressions published from inception till July 2023 were included in this review. The quality assessment of the included articles was done based on a modified Cochrane collaboration tool for crossover studies. A total of 280 articles were identified, after duplicate removal, title and abstract screening, and full-text evaluation, 7 articles were included in this systematic review. The overall quality of evidence is moderate. The CAD-CAM crowns fabricated from direct digital impressions exhibited a better marginal fit than those crowns fabricated by indirect digital impressions. The overall quality of evidence is moderate. Further clinical studies has to be conducted for evaluating the latest technologies towards achieving the misfit of zero.

Digital and conventional impression techniques of obtaining complete-arch dental impression

Impression making has become an essential procedure in dentistry.Various materials and impressiontaking processes have been utilized over time to obtain the desired accuracy for successful treatment. Aim of this study is to investigate the accuracy and trueness of digital full arch dental impressions in comparison to a conventional dental impression procedure in clinical application. This study was conducted in the department of stomatological propaedeutics “Pavel Godoroja” at the State University of Medicine and Pharmacy “Nicolae Testemițanu” and Smiles for Miles Dental Office Modesto, California. The preferences of 20 patients with full dentition were analyzed and compared regarding the use of conventional and digital impression techniques. Patients were requested to complete a comparative questionnaire in regards to their experience with each technique. The results of the comparative questionnaire presented show that 100% of patients preferred the digital impression technique when given the option for either impression. Through the questionnaire, it was determined that the comfort and satisfaction of patients was greater in the digital impression technique. Digital impression was less invasive and did not require the scanner to be placed in the mouth to the depth of the conventional impression tray. The intraoral scanner did not have any unpleasant odors or trigger gagging reflex.

Clinical comparison of marginal fit of ceramic inlays between digital and conventional impressions.

The aim of this stuldy was to compare the clinical marginal fit of CAD-CAM inlays obtained from intraoral digital impression or addition silicone impression techniques. The study included 31 inlays for prosthodontics purposes of 31 patients: 15 based on intraoral digital impressions (DI group); and 16 based on a conventional impression technique (CI group). Inlays included occlusal and a non-occlusal surface. Inlays were milled in ceramic. The inlay-teeth interface was replicated by placing each inlay in its corresponding uncemented clinical preparation and taking interface impressions with silicone material from occlusal and free surfaces. Interface analysis was made using white light confocal microscopy (WLCM) (scanning area: 694 × 510 µm2) from the impression samples. The gap size and the inlay overextension were measured from the microscopy topographies. For analytical purposes (i.e., 95-%-confidence intervals calculations and P-value calculations), the procedure REGRESS in SUDAAN was used to account for clustering (i.e., multiple measurements). For p-value calculation, the log transformation of the dependent variables was used to normalize the distributions. Marginal fit values for occlusal and free surfaces were affected by the type of impression. There were no differences between surfaces (occlusal vs. free). Gap obtained for DI group was 164 ± 84 µm and that for CI group was 209 ± 104 µm, and there were statistical differences between them (p = .041). Mean overextension values were 60 ± 59 µm for DI group and 67 ± 73 µm for CI group, and there were no differences between then (p = .553). Digital impression achieved inlays with higher clinical marginal fit and performed better than the conventional silicone materials.

The impact of digitization and conventional techniques on the fit of fixed partial dentures FPDs: systematic review and Meta-analysis

Purpose of the studyThe goal behind this study is to answer the question “In tooth-supported fixed partial dentures (FPDs), does the digital impression techniques compared to fabrications using conventional impression methods improve the marginal and internal fit?BackgroundThe incorporation of digital technology in the fabrication of fixed partial dentures (FPDs) has accelerated over the past decade. This study is directed at evaluating the marginal and internal fit of FPDs manufactured using digital approaches compared to conventional techniques. The need for updated data has encouraged this review.Materials and methodsAn electronic search was conducted in PubMed, Scopus, Web of Science, and the Grey Database to identify relevant studies. The Modified Methodological Index for Non-Randomized Studies (MINORS) was used to assess the risk of bias in in vitro experiments.The key results of this meta-analysis were the standard mean differences (SMDs) and 95% confidence intervals (CI) of each main variance, marginal fit, and internal fit between the digital and conventional techniques.Additional analyses were performed to assess the significance of three subgroup parameters: method of digitalization, cement spacer thickness, and span length, and their influence on the fit of the FPDs.ResultsBased on predefined criteria, of the seven articles included in this systematic review, only five were selected for the quantitative data analysis. The marginal fit results were (P = 0.06; SMD: -1.88; 95% CI: − 3.88, 0.11) (P > 0.05) and the internal fit results were (P = 0.02; SMD: -0.80; 95% CI: − 1.49, − 0.10) (P < 0.05).Regarding the subgroup analyses, the method of digitalization subgroup results were (P = 0.35; SMD: -1.89; 95% CI: − 3.89, 0.11) and (P = 0.80; SMD: -0.80; 95% CI: − 1.49, − 0.11) for marginal and internal fit, respectively. The span length results were (P = 0.10; SMD: -1.89; 95% CI: − 3.89, 0.11) for marginal fit and (P = 0.02; SMD: -0.80; 95% CI: − 1.49, − 0.11) for internal fit. The cement spacer thickness (P = 0.01; SMD: -1.89; 95% CI: − 3.89, 0.11) and (P = 0.04; SMD: -0.80; 95% CI: − 1.49, − 0.11) for marginal and internal fit, respectively.ConclusionTooth-retained fixed partial dentures FPDs produced by digital scanning and computer-aided design/computer-aided manufacturing (CAD/CAM) systems can significantly enhance the internal fit compared with those manufactured by traditional methods.Intraoral scanners can replace conventional impressions for the fabrication of FPDs because they minimize the operating time and reduce patient pain.Further clinical studies are required to obtain more conclusive results.Systematic review registrationThis systematic review and meta-analysis was registered in the International Prospective Register of Systematic Reviews (PROSPERO), registration number CRD42021261397.

Development of computational thinking for dental students in the use of the intraoral impressions’ technique

The accuracy of intraoral impressions is critical for making well-fitting restorations. The possibility of digitalizing the patient's mouth has once been intended for Dentistry, however, the accuracy of dental impressions for different clinical applications is still resisted by professionals. Thus, the understanding of Dentistry students can facilitate the use of the digital technique. The aim of this study was to develop the computational thinking of dentistry students for the use of the intraoral impressions’ technique. Information was collected through searches in Pubmed, Scielo, Scopus, Lilacs and Google Scholar databases using the words "digital printing", "dimensional impression accuracy", "dental impression technique", "intraoral scanner" and "Dentistry digital" in Portuguese or English. Factors such as temperature variation, time period between casting and molding, plaster surface wettability and disinfection procedures may result in material distortion and affect accuracy. Patients commonly report greater comfort when using digital impression techniques and less impression than for conventional impression techniques. Based on this literature review, the intraoral scanning over the years will replace the conventional impression, as it is currently a reliable method, and as accurate as the conventional impression, being in some cases even more precise, in addition to offering greater comfort to the dentist and patient; thus, it is extremely important for dental students to incorporate the computational use of this technique into their learning.

Digital Analysis of a Novel Impression Method Named the Biological-Oriented Digital Impression Technique: A Clinical Audit

This report aims to clinically evaluate the feasibility of a novel biological-oriented digital impression method for teeth prepared with a vertical preparation technique. Something that makes this case unique is that the definitive impression is taken without cord displacement, reducing the invasiveness for the patient. In addition, dental technicians can reproduce the exact emergence profile of the temporary restoration used to reshape the soft tissue contours and define the accurate finish line at the established prosthetic junction, potentially avoiding the aesthetic and biological issues of the double-cord technique. The finish line and emergence profile are transferred using the temporary restoration through a simple CAD procedure performed using the same software used to take the impression. This makes the proposed biological-oriented digital impression technique (BODIT) easy to perform, avoiding adjunctive time and costs for clinicians and patients. Conclusions: Finally, patients' satisfaction could be significantly improved.

EPA Consensus Project Paper: Accuracy of Photogrammetry Devices, Intraoral Scanners, and Conventional Techniques for the Full-Arch Implant Impressions: A Systematic Review.

The objective of this systematic review was to evaluate and compare the accuracy of digital impression techniques and conventional methods for full-arch implant impressions. An electronic literature search in the databases Medline (Pubmed), Web of Science, and Embase was performed to identify in vitro and in vivo publications (between 2016 and 2022) directly comparing digital and conventional abutment-level impression techniques. All selected articles passed through the data extraction procedure according to defined parameters in inclusion and exclusion criteria. Measurements on linear, angular and/or surface deviations were performed in all selected articles. Nine studies met the inclusion criteria and were selected for this systematic review. 3 articles were clinical studies and 6 studies were in vitro. Accuracy difference mean values of the trueness up to 162+/-77μm between digital and conventional techniques were reported in the clinical studies and up to 43μm in laboratory studies. Methodological heterogeneity was observed in both, in vivo and in vitro studies. Intraoral scanning and photogrammetric method showed comparable accuracy for registering implant positions in the full-arch edentulous cases. A tolerable implant prosthesis misfit threshold and objective misfit assessment criteria (for linear and angular deviations) should be verified in clinical studies.

Development and Comparison of Conventional and 3D-Printed Laboratory Models of Maxillary Defects.

Recording accurate impressions from maxillary defects is a critical and challenging stage in the prosthetic rehabilitation of patients following maxillectomy surgery. The aim of this study was to develop and optimize conventional and 3D-printed laboratory models of maxillary defects and to compare conventional and digital impression techniques using these models. Six different types of maxillary defect models were fabricated. A central palatal defect model was used to compare conventional silicon impressions with digital intra-oral scanning in terms of dimensional accuracy and total time taken to record the defect and produce a laboratory analogue. Digital workflow produced different results than the conventional technique in terms of defect size measurements which were statistically significant (p < 0.05). The time taken to record the arch and the defect using an intra-oral scanner was significantly less compared with the traditional impression method. However, there was no statistically significant difference between the two techniques in terms of the total time taken to fabricate a maxillary central defect model (p > 0.05). The laboratory models of different maxillary defects developed in this study have the potential to be used to compare conventional and digital workflow in prosthetic treatment procedures.

Accuracy of single-unit ceramic crown fabrication after digital versus conventional impressions: A systematic review and meta-analysis.

In the present era when interest in digital dentistry is increasing, the published literature is still confusing about whether digital impression provides similar accuracy as provided by a conventional impression for the fabrication of a single-unit ceramic crown. The aim of the study was to systematically review the in vivo studies comparing marginal, axial, and occlusal fit of single-unit ceramic crowns fabricated after digital impressions with the ones fabricated after conventional impressions. The PubMed, Scopus, and Cochrane online databases were searched for studies comparing the digital impression technique with the conventional technique for single-unit ceramic crowns. Data extraction was done for the year of publication, type of study, country, number of patients, impression system (intraoral scanner [IOS] or conventional impression), marginal fit, axial fit, and occlusal fit. Ten studies were included for meta-analysis regarding the discrepancy in marginal fit, axial fit, and occlusal fit. The digital impression proved to be better than the conventional impression. The mean difference for marginal fit was 6.54 μm (heterogeneity P < 0.00001, I2 = 93%), for axial fit 24.69 μm (heterogeneity P = 0.34, I2 = 11%), and for occlusal fit 6.99 μm (heterogeneity P = 0.03, I2 = 59%). The results of meta-analyses suggest that there is no significant difference between the impression systems (marginally favoring digital impression). The digital impression technique provided better marginal and internal fit of single-unit ceramic crowns than the conventional impression technique. The digital workflow using IOS provided a clinically acceptable marginal fit for single-unit crowns.

Effect of Different Digital Impression Techniques on the trueness of post space scans with fixed cervical diameter

Effect of Different Digital Impression Techniques on the trueness of post space scans with fixed cervical diameter

Conventional vs. Digital Impression: Comfort Level, Preferences, and Acceptance of Treatment Time among Orthodontic Patients

Background: The escalated technological development and the emergence of computer-aided manufacturing have improved dental restoration accuracy and the accurate manufacturing of prosthetic models. Objective: The study aims to assess patients' comfort level, preferences, and acceptance of treatment time for conventional impression technique vs. digital impression among orthodontic patients treated with clear aligners. Methods: A cross-sectional survey study was conducted between February 2019 and April 2019 by recruiting 50 patients from the orthodontic clinics at multiple centers. A self-administered questionnaire was designed to evaluate patients' perceptions in each impression technique group. Descriptive statistics and paired sample t-test were applied with statistical significance set at P&lt;0.05. Results: The results showed that the impression technique bothered patients as they experienced helplessness during treatment. There was a significant impact on patients' perception of the treatment, whereas there was an insignificant association between comfort level and treatment of the patients. Conclusion: The technicalities of conventional impression were not applied to the intraoral scanners, making these scanners superior and more user-friendly. Digital impression techniques were also preferred by the participants regarding their time, taste/smell, and sensitivity.

Accuracy of Conventional Versus Digital Impression Techniques in Construction of Digitally Printed Surgical Guide "In Vitro Study"

Accuracy of Conventional Versus Digital Impression Techniques in Construction of Digitally Printed Surgical Guide "In Vitro Study"

Evaluating the accuracy of intraoral direct digital impressions in 2 infants with unilateral cleft lip and palate compared with digitized conventional impression

Presurgical infant orthopedics was introduced as an interceptive approach for treating cleft lip and/or palate (CLP). This study aimed to evaluate the intraoral digital impression technique as a viable alternative to conventional impression in infants with unilateral CLP. Trios 3-Shape scanner (3Shape, Copenhagen, Denmark) was used for intraoral scanning of the infants' maxillary arches to provide a direct digital scan (DDS). In addition, conventional impressions of the same patients were taken in a hospital setting, and the resultant stone models were digitized using the same scanner to create an indirect digital scan (IDS). Both scans (DDS and IDS) were exported in stereolithography format, and the resultant stereolithography files were imported into computer-assisted-design software (Exocad DentalCAD; exocad GmbH, Darmstadt, Germany) for 3-dimensional surface model superimposition. Differences between the 2 surfaces were quantified in millimeters and visually displayed by a color map. Three-dimensional surface model superimposition of the DDS and IDS scans showed an excellent agreement between both approaches, in which differences ranged from 0.01 mm to 0.1 mm CONCLUSIONS: Intraoral direct digital impression in infants with unilateral CLP is a safe, accurate, and time-efficient technique, which can be a viable alternative to conventional impression. This will aid in overcoming the challenges and complications that are frequently associated with using conventional impressions in infants with unilateral CLP, thus reducing the burden of care not only on the patients' families but also on the care providers.

An Indirect Digital Technique to Transfer 3D Printed Casts to a Mechanical Articulator With Individual Sagittal Condylar Inclination Settings Using CBCT and Intraoral Scans.

With the widespread application of digital impression techniques in prosthetic dentistry, accurate intraoral scan mounting, and virtual articulator parameters setting as per patients' anatomic structures are essential for treatment planning and restoration fabrication, especially for complex rehabilitation cases; meanwhile, marginal fit checking, occlusal adjustment, and porcelain layering of restorations are also crucial procedures in all cases in which the analog procedure to mount maxillary arches on a mechanical articulator is still required. This technique article presents an indirect digital approach that can first achieve virtual intraoral scan mounting and sagittal condylar inclination value setting of an Artex virtual articulator based on bony structures provided by a single cone beam computed tomography scan. It then facilitates the transfer of virtually mounted intraoral scans from the virtual articulator to the matched Artex mechanical articulator by relating a digitally scanned mounting plate of the Artex mechanical articulator to the virtual articulator, printing the intraoral scan and mounting plate scan assembly, and then mounting the printed casts on the mechanical articulator based on the printed mounting plate. This technique eliminates the conventional facebow transfer and protrusive bite registration procedures and offers a straightforward approach for the seamless integration of virtual environments and analog workflows into clinical practice. It aids in the design of restorations that are harmonious with the mandibular movements and reduces chairside adjustment time.