Digital Impression Techniques Research Articles

Effect of soft tissue thickness on accuracy of conventional and digital implant impression techniques

BackgroundPlacing implants deep sub-gingivally may affect the accuracy of implant impression techniques and the fit of final restoration.PurposeThe aim of this in-vitro study was to evaluate the effect of soft tissue thickness on accuracy of conventional and digital implant impression techniques.MethodsFour parallel implant analogues (A, B, C, D) placed in each of two epoxy resin models representing edentulous mandible covered by flexible polyurethane material with two different thickness two mm and four mm. A total of sixty impressions performed, thirty impressions for each model divided into four groups (n = 15 per group) GI (C2mm) open tray impression with two mm implant depth, GII (C4mm) open tray impression with four mm implant depth, GIII (D2mm) digital impression with two mm implant depth, GIV (D 4 mm) digital impression with four mm implant depth. Impressions from open tray technique were poured to get stone casts while impressions from digital scanning technique were printed as three-dimensional printed casts. The six inter-implant distances between analogues were measured using Co-ordinate measuring machine, deviations compared to reference models were calculated. Data was collected, tabulated and statistically analyzed using One-way ANOVA test to detect significances between groups.ResultsFor conventional impressions there was significant difference between C2mm/C4mm (P < 0.001) regarding interimplant distance, while in digital impressions there was no significant difference between D2mm/D4mm AB(p = 0.110), BC(p = 0.066), CD(p = 0.710), AD(p = 0.084), AC(p = 0.067) and BD(p = 0.072). There was significant difference between conventional and digital impression techniques C2mm/D2mm, C4mm/D4mm (P < 0.001).ConclusionWithin the limitations of this in-vitro study digital impressions provide more accurate outcomes with implants placed deeper subgingivally than conventional impressions.Trial registrationRetrospectively registered.

Direct vs. Indirect Digital Implant Impressions: A Time and Cost Analysis

Background/Objectives: This study aimed to compare the cost and time implications for implant-supported prosthesis comparing three digital impression techniques: digitization with an intraoral scanner, digitization of the conventional impression (without dental casts) and digitization of the stone models. Methods: To assess the time and cost of digital impression techniques on implants, time records on intraoral scans were consulted and three models were created with one, two and six implants to assess extraoral procedures time. Costs were evaluated based on material consumption, time expenditure and operator-related expenses. Time was recorded in three stages: (1) impression-taking, (2) model fabrication and (3) overall workflow completion. Statistical analysis was performed using ANOVA to compare cost and time differences across workflows. Results: Intraoral scanning presented a reduction in chair-side time between 4 and 20% when compared to extraoral techniques. For the three clinical situations evaluated, the intraoral scanning always presented the lowest cost. The extraoral digitization of impressions showed a reduction between 51.9% and 53.6% in laboratory time and between 3.5% and 7.6% in total cost compared to stone models digitization. Conclusions: The findings of this study indicate that intraoral scanning is a more cost-effective and time-efficient alternative to traditional impression methods, providing advantages in terms of reduced material use and shorter procedural durations.

Research progress on accuracy of intraoral digital impressions for implant-supported prostheses in edentulous jaw

With the rapid development of implant techniques and digital technology, intraoral digital impressions have become a commonly used impression method in implant restoration. At present, the accuracy of intraoral digital impressions directly applied to implant-supported prostheses in edentulous jaw remains inadequate. This is due to the high accuracy requirement of full-arch implant impressions, while there are still technical challenges in intraoral digital impressions about recognition and stitching. In this regard, scholars have proposed a variety of scanning strategies to improve the accuracy of intraoral scans, including mucosal modifications, auxiliary devices and novel scan bodies. At the same time, as a new digital impression technique, stereo photogrammetry has been developing steadily and exhibits promising accuracy. This article reviews the research progress on the accuracy of edentulous full-arch implant impressions and techniques which can improve the accuracy of intraoral digital impressions thus providing a reference for clinical application.

A Comparative Literature Review of Digital and Conventional Impressions in Prosthodontic Practice: From Patient Comfort to Clinical Outcomes

Background: Dental impressions have traditionally been taken using conventional methods, which are time-consuming and often uncomfortable for patients. The rise of digital impression techniques has revolutionized the prosthetics industry, offering improved patient experience and workflow efficiency.Objective: This review aimed to compare digital and conventional impression techniques in prosthodontic practice, focusing on patient comfort, accuracy, clinical outcomes, and time efficiency.Methods: A systematic review was conducted following PRISMA guidelines. Databases including PubMed, Scopus, and Web of Science were searched for studies published between 2010 and 2024. Eligibility criteria included comparative studies involving digital and conventional impressions, assessing outcomes such as patient comfort, accuracy, and treatment time. Data were extracted independently by two reviewers and analyzed qualitatively.Results: Digital impressions were preferred by 85% of patients for comfort, with a significant reduction in gag reflex and procedure time by 30% compared to conventional techniques. Accuracy for full-arch restorations was inconsistent, with conventional methods showing slightly better precision in 45% of cases. Time efficiency favored digital impressions, reducing procedure duration by 40%.Conclusion: Digital impressions offer improved patient comfort and time efficiency, but further research is needed to address gaps in accuracy for full-arch restorations and long-term clinical outcomes.

Comparison of Direct Intraoral Scan and Traditional Impression for CAD/CAM Mandibular Overdenture Base: RCT on Peri-implant Marginal Bone Changes.

This study aimed to evaluate the impact of digital vs traditional impression techniques on peri-implant vertical bone resorption in the creation of mandibular overdenture bases supported by four implants using CAD/CAM technology. Twenty edentulous patients were placed in four mandibular implants and randomly divided into groups: (A) the control group (CIG) (n = 10); patients obtained CAD/CAM denture base using conventional impression technique and group (B) the study (DIG) group (n = 10); patients obtained CAD/CAM denture base using digital impression technique. Peri-implant vertical bone height was measured immediately (T0), 6 (T6), and 12 (T12) months after insertion. Peri-implant vertical bone loss (VBL) was calculated first 6 months (T1), the second 6 months (T2), and 1 year (T3) after insertion. For both groups, the survival rates of inserted implants were 100%. The amount of VBL in the first year in both groups was within normal ranges. In both groups, VBL significantly decreased over time. The control group recorded significantly higher VBL than (DIG) group at T2 (p = 0.006) and at T3 (p = 0.005). Digital intraoral scanning technique may be considered a more beneficial registration method than traditional impression technique for the construction of CAD/CAM 4-implant-assisted overdenture base regarding the preservation of vertical bone levels. Both digital intraoral scanners and conventional impression techniques can be used for the construction of CAD/CAM-implant-assisted overdenture bases regarding the preservation of peri-implant vertical bone resorption. How to cite this article: Seifeldeen AR, Aboelez MA, Gebreel AA, et al. Comparison of Direct Intraoral Scan and Traditional Impression for CAD/CAM Mandibular Overdenture Base: RCT on Peri-implant Marginal Bone Changes. J Contemp Dent Pract 2024;25(6):527-534.

COMPARISON OF THREE-DIMENSIONAL (3D) ACCURACY BETWEEN CONVENTIONAL AND DIGITAL IMPRESSIONS FOR MULTIPLE IMPLANTS SUPPORTED PROSTHESIS:AREVIEW

One of the most dramatic transformations in the field of dentistry has been the embrace of modernized computer-aided design(CAD) and computer-aided manufacturing(CAM)dentistry. Today, innovative dental offices can leverage these technological advancements in the dentistryto make the tooth restoration process more efficient, cost-effective, and accurate, all of which can lead to better patient experiences and outcomes.Digitalimpressions can simplify and improve the impression process. The use of digital impressions has gained more popularity due to the production of comparable precise models and reduction of the digital workflow process.Thisreview article explores various techniques used for conventional and digital impression and to compare the 3Daccuracy of conventional and digital impression techniques for multiple implants in edentulous areas.

The accuracy of conventional versus digital (intraoral scanner or photogrammetry) impression techniques in full-arch implant-supported prostheses: a systematic review.

This systematic review aimed to compare the accuracy of conventional impression techniques with digital methods, including intraoral scanners or photogrammetry, in full-arch implant-supported prostheses. An electronic search of the MEDLINE (PubMed, Scopus, and Cochrane) databases was conducted following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. The review included in vitro studies published between January 2000 to January 2024 that compared the accuracy of digital and conventional implant impression techniques. Descriptive analyses were performed using the data extracted from each study. Twenty-three in vitro studies met the inclusion criteria. Of these, eighteen utilized intraoral scanners and five employed photogrammetry. Twelve studies concluded that digital techniques were more accurate than conventional methods, six found conventional techniques to be more accurate, and five reported comparable accuracy between the two methods. Within limitation of the included studies, digital implant impression technique were generally more accurate than conventional methods for full-arch implant-supported prostheses. This review suggests that future research should use perform standardized methodologies and report consistent accuracy outcomes to enable the inclusion of more studies in a meta-analysis. The study was registered in PROSPERO (ID: CRD42023397916).

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 conventional impressions. [Correction added on 11 June 2024, after first online publication: In the preceding sentence, "digital impressions" was changed to "conventional impressions" in this version.] CONCLUSION: 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.

Comparación de dimensiones dentales en modelos desarrollados con procedimientos digitales y modelos en yeso

Aim: This study aimed to collect evidence on the validity and reliability of measurements obtained from digital impression techniques. Materials and Methods: This comparative study was conducted on 31 patients. Intraoral scanner was applied to all patients. For each patient, an alginate impression of the upper maxilla was taken and later the 3D digital model was extracted by dental cone-beam computed tomography (CBCT). For preparation of plaster models, alginate impressions were taken and immediately poured with dental stone. In the next stage, a comparison was performed among the intraoral scanner, CBCT, and plaster models in terms of tooth size, dental width, and intra-arch dimensions. Results: Measuring tooth size and intra-arch dimensions in digital images obtained from intraoral scanner and CBCT were in most cases lower than the results obtained in the plaster models but the differences between digital techniques and plaster models are not clinically noticeable. Conclusions: Digital systems including intraoral scanner and CBCT are acceptable for clinical use in terms of accuracy.

Comparison of Internal and Marginal Adaptation of Endocrowns at Different Depths Fabricated by the Digital and Conventional Impression Techniques: Internal and Marginal Fit of Endocrowns.

Introduction: Sufficient information is not available regarding the comparative accuracy of digital and conventional impression techniques at different depths for the fabrication of endocrown restorations. Thus, this study aimed to compare the marginal (M) and internal (I) adaptation of endocrowns at different depths fabricated by the digital and conventional impression techniques. Materials and Methods: In this in vitro study, two endodontically treated molar teeth with 2- and 4-mm cavity depths were used for the fabrication of endocrowns. Conventional and digital impressions were made from each tooth 17 times. A total of 68 zirconia endocrowns were fabricated and seated, and their I and M adaptation was assessed by the silicone replica technique. Data were statistically analyzed. Results: The M and I gaps at 2- and 4-mm cavity depths were significantly smaller in the digital, than the conventional, impression technique (p < 0.05). Increasing the cavity depth significantly increased the M and I gaps only in the digital technique (p < 0.05). The largest gap in all groups was noted in the pulpal (P) region (p < 0.05). The smallest gap was found in the M and cervical (C) regions in the conventional groups with 2- and 4-mm cavity depths, and the digital group with 4 mm cavity depth, and in the M region in the digital group with 2 mm cavity depth (p < 0.05). Conclusion: Unlike the conventional impression technique, the M and I adaptation decreased by an increase in cavity depth in the digital technique; nonetheless, the digital impression technique still showed higher M and I adaptation than the conventional technique.

Ефективність цифрових і звичайних відбитків, що застосовуються при заміщенні дефектів твердих тканин зубів бічних зубів: оцінка сприйняття пацієнтів, комфорту лікування та витраченого часу

Introduction. The accuracy of the final impressions significantly affects the quality of the manufactured prosthesis. The transfer of perfect impressions to dental laboratories is always performed by dentists as part of the daily work of manufacturing prostheses in fixed prosthodontics. The accuracy of the impression depends on the materials themselves, the types of impression spoons and the impression technique. Various materials and printing techniques are used to obtain high-precision impressions. Goal. To conduct a comparative evaluation of the effectiveness of digital and conventional impressions used in the replacement of hard tissue defects of teeth of lateral teeth: assessment of patient perception, treatment comfort and time spent. To investigate the level of stress perceived by the patient at the stages of orthopedic treatment. Research material and methods. The study involved 46 patients aged 25-60 years (22 men and 24 women) who applied for orthopedic treatment of 57 defects of hard tissues of lateral teeth and had no previous experience of using conventional or digital impressions. The patient’s perceived source of stress was assessed using a modified version of the Norman Core test. Dental arch impressions were taken using polyester impression material, and bite registration was performed using polysiloxane bite registration material. Two weeks later, digital impressions and bite scans were performed on the same patients using an intraoral scanner. Both procedures were evaluated by the patients’ perception using a visual analogue scale (VAS). Patients’ perception of various impression-taking techniques was assessed using a standardized questionnaire. The stages of print processing (tray selection, working time, etc.) were recorded in seconds. The results. We found gender variations in psychoemotional reactions to specific dental interventions, highlighting potential psychological and emotional differences between male and female participants. the prevalence of strong and very strong fear of orthopedic surgery was slightly higher among female participants than among male participants. The average total time of obtaining a print using the traditional technique was 831.11 ± 5.56 s. It took half as much time to obtain prints using the digital method - 396.07 ± 7.98 seconds. In women, when receiving digital and conventional prints, the VAS indicators were lower than in men, which indicates a worse perception of the procedure by them. However, with the use of digital impressions, both women and men felt significantly higher VAS scores, which proved the advantage of using a digital method of obtaining impressions. The digital impression technique was most acceptable to both male and female patients and was preferred by all subjects. However, it is necessary to note the difference in the distribution of preferences between men and women. Conclusion. The results of the conducted study indicate that the effectiveness of the digital impression technique was higher than the traditional impression technique in terms of time spent on treatment, occurrence of adverse reactions, comfort and perception of subjects. Therefore, intraoral scanners are a clear advantage for patients visiting the dentist. Key words: defects of hard dental tissues, digital and standard impressions, patients’ feelings, stress level.

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.