Accuracy of edentulous full-arch implant impression: An in vitro comparison between conventional impression, intraoral scan with and without splinting, and photogrammetry.

OBJECTIVES: The purpose of this in vitro study was to compare the trueness and precision of complete arch implant impressions using conventional impression, intraoral scanning with and without splinting, and stereophotogrammetry. MATERIALS AND METHODS: An edentulous model with six implants was used in this study. Four implant impression techniques were compared: the conventional impression (CI), intraoral scanning (IOS) without splinting, intraoral scanning with splinting (MIOS), and stereophotogrammetry (SPG). An industrial blue light scanner was used to generate the baseline scan from the model. The CI was captured with a laboratory scanner. The reference best-fit method was then applied in the computer-aided design (CAD) software to compute the three-dimensional, angular, and linear discrepancies among the four impression techniques. The root mean square (RMS) 3D discrepancies in trueness and precision between the four impression groups were analyzed with a Kruskal-Wallis test. Trueness and precision between single analogs were assessed using generalized estimating equations. RESULTS: Significant differences in the overall trueness (p = .017) and precision (p < .001) were observed across four impression groups. The SPG group exhibited significantly smaller RMS 3D deviations than the CI, IOS, and MIOS groups (p < .05), with no significant difference detected among the latter three groups (p > .05). CONCLUSIONS: Stereophotogrammetry showed superior trueness and precision, meeting misfit thresholds for implant-supported complete arch prostheses. Intraoral scanning, while accurate like conventional impressions, exhibited cross-arch angular and linear deviations. Adding a splint to the scan body did not improve intraoral scanning accuracy.

Influence of scanning protocol on the accuracy of complete-arch digital implant scans: An in vitro study.

OBJECTIVE: This in-vitro study assessed the influence of two intraoral scanning (IOS) protocols on the accuracy (trueness and precision) of digital scans performed in edentulous arches. METHODS: Twenty-two abutment-level master casts of edentulous arches with at least four implants were scanned repeatedly five times, each with two different scanning protocols. Protocol A (IOS-A) consisted of scanning the edentulous arch before inserting the implant scan bodies, followed by their insertion and its subsequent digital acquisition. Protocol B (IOS-B) consisted of scanning the edentulous arch with the scan bodies inserted from the outset. A reference scan from each edentulous cast was obtained using a laboratory scanner. Trueness and precision were calculated using the spatial fit analysis, cross-arch distance, and virtual Sheffield test. Statistical analysis was performed using generalized estimating equations (GEEs). Statistical significance was set at α = .05. RESULTS: In the spatial fit test, the precision of average 3D distances was 45 µm (±23 µm) with protocol IOS-A and 25 µm (±10 µm) for IOS-B (p < .001), and the trueness of average 3D distances was 44 µm (±24 µm) with protocol IOS-A and 24 µm (±7 µm) for IOS-B (p < .001). Cross-arch distance precision was 59 µm (±53 µm) for IOS-A and 41 µm (±43 µm) for IOS-B (p = .0035), and trueness was 64 µm (±47 µm) for IOS-A and 50 µm (±40 µm) for IOS-B (p = .0021). Virtual Sheffield precision was 286 µm (±198 µm) for IOS-A and 146 µm (±92 µm) for IOS-B (p < .001), and trueness was 228 µm (±171 µm) for IOS-A and 139 µm (±92 µm) for IOS-B (p < .001). CONCLUSIONS: The IOS-B protocol demonstrated significantly superior accuracy. Placement of scan bodies before scanning the edentulous arch is recommended to improve the accuracy of complete-arch intraoral scanning.

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.

OBJECTIVE: The present manuscript describes a technique to virtually switch an implant scan body eliminating the need of obtaining a new intraoral implant digital scan. CLINICAL CONSIDERATIONS: 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. CONCLUSIONS: 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. CLINICAL SIGNIFICANCE: 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.

Adaptation and Biomechanical Performance of Custom-Fit Mouthguards Produced Using Conventional and Digital Workflows: A Comparative In Vitro Strain Analysis.

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

Influence of limited mouth opening in children on intraoral scanning accuracy: An in vitro study.

BACKGROUND: Although intraoral scanning is highly reliable, little is known about its accuracy in young children with limited mouth-opening ability. AIM: To determine the accuracy of intraoral scans based on the degree of mouth opening. DESIGN: To simulate mouth opening in children with primary dentition, three groups (n = 5 per group) were allocated by maximum mouth opening of 30, 37 and 40 mm. After the primary dentition model was connected to a dental phantom, intraoral scanning was performed using iTero and TRIOS4. The scanned files were digitally evaluated. Root mean square values were calculated to assess trueness and precision. RESULTS: iTero showed deviations of three-dimensional trueness of 0.067 ± 0.008, 0.063 ± 0.001 and 0.065 ± 0.005 mm, and TRIOS4 of 0.07 ± 0.002, 0.064 ± 0.003 and 0.066 ± 0.002 mm in the 30, 37 and 40 mm groups, respectively. There were no significant differences in either mouth opening (p > .017) or the intraoral scanners (p > .05). The same statistical results were obtained for precision, with the exception of the 30 mm of mouth opening. CONCLUSIONS: Within the limits of this study, limited mouth opening hardly influenced the accuracy of intraoral scanning.

Auxiliary occlusal devices for IO scanning in a complete digital workflow of implant-supported crowns: a randomized controlled trial.

OBJECTIVES: To compare the crown accuracy and time efficiency of a complete digital workflow, utilizing an auxiliary occlusal device and IO scanning, with a conventional workflow, for multiple implant-supported single crowns. MATERIALS AND METHODS: 24 patients with two adjacent posterior implants were included. 12 patients were randomly assigned to digital workflow group, involving intra-oral scanning with an auxiliary occlusal device and manufacture of customized abutments and zirconia single crowns (test group). The other 12 were assigned to the conventional workflow (control group), involving conventional impression and CAD-CAM crowns based on stone casts. Crown scanning was done before and after clinical adjustment using an intraoral scanner. Two 3D digital models were overlapped to assess dimension changes. Chair-side and laboratory times for the entire workflow were recorded and a linear mixed model and Independent-sample t tests were used for the statistical analysis. RESULTS: The maximum occlusal deviation was 279.67 ± 112.17 µm and 479.59 ± 203.63 µm in the test and control group, respectively (p < 0.001). The sizes of the occlusion adjustment areas were 12.12 ± 10.51 mm2 and 25.12 ± 14.14 mm2 in the test and control groups, respectively (p = 0.013). The mean laboratory time was 46.08 ± 5.45 and 105.92 ± 6.10 min in the test and control groups, respectively (p < 0.001).The proximal contact adjustment and mean chair-side time showed no statistically significant difference between two groups. CONCLUSIONS: A digital workflow for two implants-supported single crowns using an auxiliary device required fewer occlusal crown adjustments, and less laboratory time compared to conventional workflow. CLINICAL RELEVANCE: The use of auxiliary occlusal devices in IOS enhances the accuracy of virtual maxillomandibular relationship in extended edentulous spans. Consequently, employing a digital workflow for multiple implants-supported crowns using IO scanning and an auxiliary occlusal device proves to be a feasible, accurate and efficient approach.

Influence of augmented reality technique on the accuracy of autotransplanted teeth in surgically created sockets.

BACKGROUND: The objective of the present study was to evaluate the reliability of an augmented reality drilling approach and a freehand drilling technique for the autotransplantation of single-rooted teeth. MATERIALS AND METHODS: Forty samples were assigned to the following surgical techniques for drilling guidance of the artificial sockets: A. augmented reality technique (AR) (n = 20) and B. conventional free-hand technique (FT) (n = 20). Then, two models with 10 teeth each were submitted to a preoperative cone-beam computed tomography (CBCT) scan and a digital impression by a 3D intraoral scan. Afterwards, the autotrasplanted teeth were planned in a 3D dental implant planning software and transferred to the augmented reality device. Then, a postoperative CBCT scan was performed. Data sets from postoperative CBCT scans were aligned to the planning in the 3D implant planning software to analize the coronal, apical and angular deviations. Student's t-test and Mann-Whitney non-parametric statistical analysis were used to analyze the results. RESULTS: No statistically significant differences were shown at coronal (p = 0.123) and angular (p = 0.340) level; however, apical deviations between AR and FT study groups (p = 0.008) were statistically significant different. CONCLUSION: The augmented reality appliance provides higher accuracy in the positioning of single-root autotransplanted teeth compared to the conventional free-hand technique.

Intraoral optical impression versus conventional impression for fully edentulous maxilla: an in vivo comparative study.

AIM: The aim of the present in vivo study was to compare the clinical trueness of primary mucostatic impressions obtained either by a classical alginate or an optical intraoral scanner technique in patients with a fully edentulous maxilla. MATERIALS AND METHODS: A total of 30 patients with a fully edentulous maxilla were included in the study and underwent both conventional impressions and intraoral optical impressions (Trios 3). The conventional impressions were casted and the resulting plaster casts were digitized using a desktop scanner (Imetric D104i). These digitized impressions were superimposed over the optical impressions to compare the differences between the two data sets. Statistical analyses were performed to identify relevant deviations. RESULTS: For the 30 intraoral impressions, 80.88% of the surface areas were below the tolerance threshold of 25 µm and were thus considered similar to the areas scanned with the desktop scanner from the reference plaster cast. Interestingly, the differences (19.12% of the surface areas) were localized in depressible areas such as the vestibule, soft palate, incisive papilla, and flabby ridges. These locations were consistent with the mean of positive differences of +22.8 µm, indicating deformation or less compression with the use of the intraoral scanner. CONCLUSIONS: The digital primary impression of the fully edentulous maxilla can be considered similar to the conventional alginate impression except in the depressible areas. Considering the mucostatic objective of such a primary impression, one may consider the optical impression to be more accurate than the conventional one.

Influence of the scanning path on the accuracy of intraoral scanners in the implanted edentulous patient: an in vitro study.

AIM: The aim of this in vitro study was to investigate the influence of scan paths on the accuracy (trueness and precision) of intra-oral scanning of an implant impression on an edentulous patient. MATERIAL AND METHODS: An epoxy resin maxillary model was made with 6 bone level implants (NobelParallel Conical Connection RP, NobelBiocare®). The implants were placed at the spot of the first incisor, the canine and the first molar. The trans gingival component (Multi-unit, NobelBiocare®) was screwed onto the implants. The scanbodies (IO 2C-A, Elos Accurate®) were then screwed onto the multi-units. The model was run through a coordinate measurement machine to obtain a control cast. Then, five different scanning paths, respectively the zigzag technique (ZZT), the zigzag technique with palatal (ZZTP), the wrap technique (WT), the wrap technique with palatal (WTP), and the big zigzag technique (BZZT), were applied by a single operator. Finally, each scan was compared to the control model. Results were assessed by one-way ANOVA and linear mixed effects models at P<0.05. RESULTS: The study showed that scan paths ZZT and ZZTP had significantly lower absolute positioning errors and residual mean square errors than the others (P<0.0001). For distances between consecutive implant axes and for absolute vertical errors, their superiority was borderline (P<0.10). Overall, techniques ZZT and ZZTP were equally performant and proved to be the most accurate. CONCLUSIONS: This in vitro experimental study demonstrates that the scan path can have an influence on the accuracy of the optical impression for full arch rehabilitation on implants.

Effect of finish line location and saliva contamination on the accuracy of crown finish line scanning.

PURPOSE: Intraoral scanners are used widely as an alternative to conventional impressions, but studies on the influence of finish line location and saliva contamination on scanning trueness are lacking. The purpose of this in vitro study was to evaluate the influence of finish line location and saliva contamination on the scanning trueness of crown finish lines. MATERIALS AND METHODS: Three ivorine teeth were prepared for all-ceramic crowns with finish lines placed equigingivally, 0.5 mm subgingivally, and 1.0 mm subgingivally. A single-cord technique was used for gingival retraction, and a total of 180 intraoral scans were made using two intraoral scanners (Emerald; Planmeca USA Inc., Hoffman Estates, IL, USA & Trios 3; 3Shape A/S, Copenhagen, Denmark). The prepared teeth were separated from the dentoform and scanned using the same intraoral scanners to create reference scans. All scans were imported to the design software (Dental System 2019; 3Shape A/S, Copenhagen, Denmark). After marking the finish lines of prepared teeth, intraoral scans were aligned to the reference scans for comparisons. Vertical and horizontal marginal discrepancies were measured at four different measuring points (buccal, lingual, mesial, and distal) and analyzed. Two-way ANOVA and Tukey HSD tests were used for statistical analysis (α = 0.05). RESULTS: The average vertical and horizontal discrepancies from various groups ranged from -33 to 440 µm. For both intraoral scanners, subgingival finish line groups showed greater vertical and horizontal discrepancies compared with equigingival finish line groups. Saliva contamination significantly increased both vertical and horizontal discrepancies for all finish line locations. The discrepancy increases due to saliva contamination were greater for the subgingival groups. CONCLUSIONS: Subgingival finish lines were not accurately captured using the intraoral scanners. The presence of saliva significantly reduced scanning trueness, and this was amplified when the finish lines were located subgingivally.

Crown adjustment and chairside efficiency of single-unit restorations fabricated from immediate and staged impressions using a digital workflow for posterior implants.

PURPOSE: This is a clinical study to compare immediate and staged impression methods in a complete digital workflow for single-unit implants in the posterior area. MATERIALS AND METHODS: Sixty patients requiring single-unit implant crowns were enrolled. Forty patients were assigned to the test group, immediate digital impression after implant surgery with crown delivery 4 months later. The remaining 20 patients were assigned to the control group, staged digital impressions 4 months after implant surgery, and crown delivery 1 month later. Both workflows involved free-model CAD-CAM crown fabrications. The crowns were scanned before and after clinical adjustment using an intraoral scanner (TRIOS Color; 3Shape). Two 3D digital models were trimmed and superimposed to evaluate the dimensional changes using Geomagic Control software. Chairside times for the entire workflow were recorded. Kruskal-Wallis was performed to compare crown adjustments between two groups, while One-way ANOVA was used to compare chairside time durations between the test and control groups. RESULTS: All crowns were delivered without refabrication. The average maximum occlusion adjustment of crowns was -353.2 ± 207.1 µm in the test group and -212.7 ± 150.5 µm in the control group (p = 0.02). The average area of occlusal adjustment, measured as an area of deviation larger than 100 µm, was 14.8 ± 15.3 and 8.4 ± 8.1 mm2 in the test and control groups, respectively (p = 0.056). There were no significant differences in the mesial and distal contact adjustment amounts, or the maximum deviations of the proximal area, between the two groups. The mean chair-side time was 50.25 ± 13.48 and 51.20 ± 5.34 min in the test and control groups, respectively (p = 0.763). CONCLUSIONS: The immediate impression method in the digital workflow for single-unit implants required more occlusal adjustments of crowns but showed similar chairside times compared to the staged impression method.

In vitro evaluation of the impact of intraoral scanner, scanning aids, and the scanned arch on the scan accuracy of edentulous arches.

PURPOSE: To assess the accuracy of complete maxillary and mandibular edentulous arch scans obtained using two different intraoral scanners (IOSs), with and without scanning aids, and to compare these results to those obtained using conventional impression methods. MATERIALS AND METHODS: Two IOSs were used (TRIOS 4 [TRI] and Emerald S [EMR]) to scan maxillary and mandibular typodonts. The typodonts were scanned without scanning aids [TRI_WSA and EMR_WSA groups] (n = 10). The typodonts were then scanned under four scanning aid conditions (n = 10): composite markers [TRI_MRK and EMR_MRK groups], scanning spray [TRI_SPR and EMR_SPR groups], pressure indicating paste [TRI_PIP and EMR_PIP groups], and liquid-type scanning aid [TRI_LQD and EMR_LQD groups]. Conventional impressions of both arches were also made using irreversible hydrocolloids in stock trays [IHC] and using polyvinyl siloxane (PVS) impression material in custom trays (n = 10) which were digitized using a laboratory scanner. Using a metrology software program, all scans were compared to a reference scan in order to assess trueness and to each other to assess precision. Trueness and precision were expressed as the root mean square (RMS) of the absolute deviation values and the statistical analysis was modeled on a logarithmic scale using fixed-effects models to meet model assumptions (α = 0.05). RESULTS: The main effect of arch (p = 0.004), scanner (p < 0.001), scanning aid (p = 0.041), and the interaction between scanner and scanning aid (p = 0.027) had a significant effect on mean RMS values of trueness. The arch (p = 0.015) and scanner (p < 0.001) had a significant effect on the mean RMS values of precision. The maxillary arch had better accuracy compared to the mandible. The TRIOS 4 scanner had better accuracy than both the Emerald S scanner and conventional impressions. The Emerald S had better precision than conventional impressions. The scanning spray and liquid-type scanning aids produced the best trueness with the TRIOS 4 scanner, while the liquid-type scanning aid and composite markers produced the best trueness for the Emerald S scanner. CONCLUSION: The scanned arch and the type of scanner had a significant effect on the accuracy of digital scans of completely edentulous arches. The scanning aid had a significant effect on the trueness of digital scans of completely edentulous arches which varied depending on the scanner used.

Maxillary interim obturator prosthesis fabrication for a patient with limited mouth opening with a digital approach: A clinical report.

Squamous cell carcinoma is a common malignant condition affecting the oral cavity and may involve the surrounding maxillofacial regions. Treatment commonly involves resection of the tumor, followed by prosthetic rehabilitation of the resection defect. This clinical report presents a 62-year-old Asian male patient who had previously undergone surgical resection, resulting in a post-surgical Aramany Class II maxillary defect. The patient's medical history included severe trismus, characterized by restricted mouth opening, as well as a diagnosis of maxillary sinus verrucous squamous cell carcinoma. This report provides a comprehensive account of the rapid fabrication of an interim obturator using digitally assisted dentistry techniques.

Research progress on accuracy of intraoral digital impressions for implant-supported full-arch prostheses. / æ— ç‰™é¢Œç§æ¤ä¿®å¤å£å† æ•°å­—åŒ–å°æ¨¡å‡†ç¡®æ€§ç ”ç©¶è¿›å±•.

With the rapid development of implant techniques and digital technology, 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 full-arch prostheses remains inadequate, which 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 scan, including mucosal modifications, auxiliary devices and novel scan bodies. At the same time photogrammetry, as a new digital impression technique, 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, to provide reference for clinical application.

THE ACCURACY OF INTRAORAL SCAN IN OBTAINING DIGITAL IMPRESSIONS OF EDENTULOUS ARCHES: A SYSTEMATIC REVIEW.

OBJECTIVES: Accuracy is a crucial factor when assessing the quality of digital impressions. This systematic review aims to assess the accuracy of intraoral scan (IOS) in obtaining digital impressions of edentulous jaws. METHODS: This systematic review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and was registered in the International Prospective Register of Systematic Reviews (PROSPERO ID: CRD42022382983). A thorough retrieval of 7 electronic databases was undertaken, encompassing MEDLINE (PubMed), Web of Science, EMBASE, Scopus, Cochrane Library, Virtual Health Library, and Open gray, through September 11, 2023. A snowball search was performed by tracing the reference lists of the included studies. The Population, Intervention, Comparison, and Outcome (PICO) question of this systematic review was: "What is the accuracy of intraoral scan in obtaining digital impressions of edentulous arches?" The Modified Methodological Index for Nonrandomized Studies (MINORS) was employed to assess the risk of bias. RESULTS: Among the studies retrieved from databases and manual search, a total of 25 studies were selected for inclusion in this systematic review, including 9 in vivo and 16 in vitro studies. Twenty-one of the included studies utilized the 3D deviation analysis method, while 4 studies employed the linear or angular deviation analysis method. The accuracy results of in vitro studies indicated a trueness range of 20-600 µm and a precision range of 2-700 µm. Results of in vivo studies indicated a trueness range of 40-1380 µm, while the precision results were not reported. CONCLUSION: According to the results of this study, direct digital impressions by IOS cannot replace the conventional impressions of completely edentulous arches in vivo. Edentulous digital impressions by IOS demonstrated poor accuracy in peripheral areas with mobile tissues, such as the soft palate, vestibular sulcus, and sublingual area.

Accuracy of complete-arch digital implant impression with intraoral optical scanning and stereophotogrammetry: An in vivo prospective comparative study.

OBJECTIVES: To assess accuracy of intraoral optical scanning (IOS) and stereophotogrammetry (SPG), complete-arch digital implant impressions in vivo. MATERIALS AND METHODS: Consecutive patients needing implant-supported screw-retained zirconia complete-arch fixed-dental prostheses (ISZ-FDP) were recruited. For each patient, three impressions were taken: IOS, SPG (tests), and open-tray plaster (reference). Linear (ΔX, ΔY, and ΔZ), three-dimensional (ΔEUC), and angular deviations (ΔANGLE) were evaluated and stratified according to scanning technology for each implant. Potential effects of impression device (IOS and SPG), arch (maxilla and mandible), and implant number (4 and 6) were evaluated through multivariable analysis. Significance level was set at .05. RESULTS: A total of 11 complete arches (5 maxillae, 6 mandibles) in 11 patients were rehabilitated with ISZ-FDPs supported by 4 (n = 8) and 6 implants (n = 3). A total of 50 implants and 100 implant positions were captured by two investigated devices and compared to respective reference (mean ΔEUC IOS 137.2, SPG 87.6 µm; mean ΔANGLE 0.79, 0.38°). Differences between measurements (SPG-IOS) were computed for each implant, with negative values indicating better SPG accuracy. Significant mean ΔEUC difference of -49.60 µm (p = .0143; SD 138.15) and mean ΔANGLE difference of -0.40° (p < .0001; SD 0.65) were observed in favor of SPG. Multivariable analysis showed significant effect on ΔEUC (p = .0162) and ΔANGLE (p = .0001) only for impression devices, with SPG performing better. CONCLUSIONS: SPG experienced significantly higher linear and angular accuracy. No effect of type of arch or implant number was detected. Higher extreme deviations were experienced for IOS. SPG can be feasible for complete-arch digital impressions with caution, and rigid prototype try-in is recommended before screw-retained prosthesis manufacturing.

Enhancing intraoral scanner accuracy using scan aid for multiple implants in the edentulous arch: An in vivo study.

OBJECTIVES: Intraoral scans of multiple implants in the edentulous arch are challenged by the absence of a distinct surface morphology between scan bodies. A scan aid was applied in such situation and evaluated for intraoral scanning accuracy in vivo. MATERIALS AND METHODS: 87 implants in 22 patients were scanned with scan aid (SA) and without scan aid (NO) using two different intraoral scanners (CS3600 [CS] and TRIOS3 [TR]). Master casts were digitized by a laboratory scanner. Virtual models were superimposed using an inspection software and Linear deviation and precision were measured. Statistical analysis was performed using linear mixed models (α = .05). RESULTS: Total mean linear deviation within the CS group was 189 µm without scan aid and 135 µm when using the scan aid. The TR group's total mean deviation was 165 µm with and without a scan aid. Significant improvement with scan aid was observed for the CS group (p = .001), and no difference was found in the TR group. 96% of scan bodies were successfully scanned in the TR-SA group compared to 86% for the TR-NO group, 83% for the CS-SA, and 70% for the CS-NO group, respectively. CONCLUSIONS: The evaluated scan aid improved linear deviation compared to unsplinted scans for the CS group but not for the TR group. These differences could originate from different scanning technologies used, active triangulation (CS) and confocal microscopy (TR). The scan aid improved the ability to recognize scan bodies successfully with both systems, which could have a favorable clinical impact overall.

The Initial Relationship Between the United States Department of Health and Human Services' Digital COVID-19 Public Education Campaign and Vaccine Uptake: Campaign Effectiveness Evaluation.

BACKGROUND: Over 1 million people in the United States have died of COVID-19. In response to this public health crisis, the US Department of Health and Human Services launched the We Can Do This public education campaign in April 2021 to increase vaccine confidence. The campaign uses a mix of digital, television, print, radio, and out-of-home channels to reach target audiences. However, the impact of this campaign on vaccine uptake has not yet been assessed. OBJECTIVE: We aimed to address this gap by assessing the association between the We Can Do This COVID-19 public education campaign's digital impressions and the likelihood of first-dose COVID-19 vaccination among US adults. METHODS: A nationally representative sample of 3642 adults recruited from a US probability panel was surveyed over 3 waves (wave 1: January to February 2021; wave 2: May to June 2021; and wave 3: September to November 2021) regarding COVID-19 vaccination, vaccine confidence, and sociodemographics. Survey data were merged with weekly paid digital campaign impressions delivered to each respondent's media market (designated market area [DMA]) during that period. The unit of analysis was the survey respondent-broadcast week, with respondents nested by DMA. Data were analyzed using a multilevel logit model with varying intercepts by DMA and time-fixed effects. RESULTS: The We Can Do This digital campaign was successful in encouraging first-dose COVID-19 vaccination. The findings were robust to multiple modeling specifications, with the independent effect of the change in the campaign's digital dose remaining practically unchanged across all models. Increases in DMA-level paid digital campaign impressions in a given week from -30,000 to 30,000 increased the likelihood of first-dose COVID-19 vaccination by 125%. CONCLUSIONS: Results from this study provide initial evidence of the We Can Do This campaign's digital impact on vaccine uptake. The size and length of the Department of Health and Human Services We Can Do This public education campaign make it uniquely situated to examine the impact of a digital campaign on COVID-19 vaccination, which may help inform future vaccine communication efforts and broader public education efforts. These findings suggest that campaign digital dose is positively associated with COVID-19 vaccination uptake among US adults; future research assessing campaign impact on reduced COVID-19-attributed morbidity and mortality and other benefits is recommended. This study indicates that digital channels have played an important role in the COVID-19 pandemic response. Digital outreach may be integral in addressing future pandemics and could even play a role in addressing nonpandemic public health crises.

Retrospective clinical study of 1472-unit monolithic zirconia restorations with feather-edge margins realized with digital workflow.

OBJECTIVES: To evaluate the clinical performance of monolithic zirconia restorations with feather-edge margins fabricated by digital impressions. MATERIALS AND METHODS: All participants that present monolithic zirconia restorations with feather-edge margins realized with digital workflow were evaluated during scheduled periodontal maintenance between February and September 2022 according to predetermined inclusion criteria. Clinical performance was assessed using the modified USPHS and periodontal parameters. Overall survival was calculated for monolithic zirconia restorations. Technical and biologic complications were reported. Descriptive statistical analysis and life-table analyses were performed for all data. RESULTS: A total of 1472 monolithic zirconia FDPs (1279 on abutments and 193 on pontics) placed in 1189 patients (982 males and 490 females) from February 2017 to September 2020 were analyzed. The mean follow-up was 44 months (range 36-61 months), and the overall survival rate was 98.5%. There were 931 single crowns, 96 were 3-unit FDPs, 33 were 4-unit FDPs, 11 were 5-unit FDPs, and 6-unit FDPs. Three single crowns had irreparable cracks, and 6 single crowns and one 4-unit FDP were fractured. One 3-unit FDP failed due to tooth fracture and 5 single crowns failed due to endodontic failure. The loss of retention was noted in 25 monolithic zirconia FDPs and hypersensitivity in 44 single crowns. Biologic complications were uncommon. CONCLUSIONS: Based on the results and its limitations, the monolithic zirconia FPDs and digital impressions represent a favorable prosthetic treatment similar to that reported with other margin designs CLINICAL RELEVANCE: Monolithic zirconia restorations on vertical-margin abutments fabricated using a digital workflow demonstrate excellent clinical performance. The digital clinical workflow without the use of a cast means a reduction in costs, steps, and operating time.

Application of three-dimensional reconstruction technology in dentistry: a narrative review.

BACKGROUND: Three-dimensional(3D) reconstruction technology is a method of transforming real goals into mathematical models consistent with computer logic expressions and has been widely used in dentistry, but the lack of review and summary leads to confusion and misinterpretation of information. The purpose of this review is to provide the first comprehensive link and scientific analysis of 3D reconstruction technology and dentistry to bridge the information bias between these two disciplines. METHODS: The IEEE Xplore and PubMed databases were used for rigorous searches based on specific inclusion and exclusion criteria, supplemented by Google Academic as a complementary tool to retrieve all literature up to February 2023. We conducted a narrative review focusing on the empirical findings of the application of 3D reconstruction technology to dentistry. RESULTS: We classify the technologies applied to dentistry according to their principles and summarize the different characteristics of each category, as well as the different application scenarios determined by these characteristics of each technique. In addition, we indicate their development prospects and worthy research directions in the field of dentistry, from individual techniques to the overall discipline of 3D reconstruction technology, respectively. CONCLUSIONS: Researchers and clinicians should make different decisions on the choice of 3D reconstruction technology based on different objectives. The main trend in the future development of 3D reconstruction technology is the joint application of technology.