The accuracy of intraoral and extraoral scanners for different models of edentulousness is unclear.
The purpose of this in vitro evaluation was to determine the accuracy (trueness and precision) of ...complete-arch scans made by 3 intraoral and 1 extraoral scanners compared with an industrial 3D scanner.
Digital scans were made of a reference cast with 3 intraoral scanners (CEREC Omnicam; Dentsply Sirona, TRIOS 3; 3shape A/S; Carestream CS 3600; Carestream Dental) and an extraoral scanner (Deluxe scanner; Open Technologies). A dental maxilla model was used for tooth preparation for ceramic restorations with a shoulder finishing line. Maxillary right central and lateral incisors and third molar and maxillary left second premolar and first and third molar teeth were removed. One operator scanned the reference cast 10 times with each scanner. All the recorded standard tessellation language (STL) files were imported into an inspection software program and individually overlaid on the STL file for the reference model made by the 3D scanner. The measured distance between the distal point of the maxillary left second molar tooth and the mesial point of the maxillary left first premolar was defined as distance 1; distance 2 was defined as the distance between the mesial point of the maxillary second molar tooth and the distal point of the maxillary right first premolar tooth. The Levene test for homoscedasticity of variances was used to evaluate precision, and a 2-way repeated-measures ANOVA and Bonferroni-corrected Student t tests were used to evaluate trueness (α=.05).
A statistically significant difference was found between the Carestream scanner and the other scanners when scanning both mucosa and teeth. The Carestream scanner had the lowest accuracy and highest magnitude mean deviation of all the scanners.
Obtaining an accurate partial-arch impression is still challenging for some intraoral scanners. The Carestream scanner’s trueness was outside the acceptable range. However, other scanners tested here appeared to be suitable alternatives to conventional impression techniques.
The aims of this pilot investigation were to calculate the levels of sensitivity and specificity of salivary glands ultrasonography (SGUS) in diagnosing Sjögren syndrome (SS) and to assess the ...ultrasonographic findings of parotid and submandibular glands.
Patients diagnosed with SS or dry mouth and healthy controls were enrolled. Bilateral parotid and submandibular glands were assessed for (1) parenchymal inhomogeneity (PIH), (2) median size of the glands, (3) visibility of glandular posterior borders, and (4) size of sialolith, if present.
This study included 34 female patients, of whom 12 had SS (35.3%), 12 had dry mouth (35.3%), and 10 were healthy controls (29.4%). Patients with SS showed higher PIH scores in all glands with the median differences being statistically higher in the right and left parotids and left submandibular glands (P < .001, P = .012, and P < .001, respectively). SGUS, with a PIH cutoff ≥2, showed a sensitivity of 100% and a specificity of 81.6% for detecting SS. The majority of SS had invisible glandular posterior borders (P < .001). Median size of the glands and size of the sialolith did not show any statistically significant differences between groups.
SGUS is a noninvasive imaging modality with good sensitivity and specificity that might be valuable as a diagnostic aid for SS.
To assess the prevalence of and identify factors associated with SPIN in abstracts of orthodontic meta-analyses.
Electronic search was performed within the contents of five orthodontic journals and ...the Cochrane Database of Systematic Reviews (CDSR) to identify meta-analyses of studies involving humans, from 1 January 2000 until 31 August 2020. Inclusion of SPIN in the abstract of meta-analyses, defined as misleading reporting, misleading interpretation, and inappropriate extrapolation of the findings, was documented. Extent of SPIN and associations with journal and year of publication, type of study, number of authors, continent of authorship, methodologist involvement, funding, and significance of the primary outcome were investigated.
One hundred and nine meta-analyses were identified, with the highest proportion being published in the European Journal of Orthodontics (EJO: 31/109; 28.4%). Inclusion of SPIN, in at least one domain, was recorded in nearly half (53/109; 48.6%) of the studies, of which 30 (56.6%) included 2 or more domains of SPIN. Meta-analyses of observational studies presented 1.66 times higher risk for including SPIN in their abstracts compared with interventional ones 95% confidence intervals (CIs): 1.14, 2.40; P = 0.007, after adjusting for a number of predictors. Studies with a large number of authors (≥6) presented 1.76 times higher risk of SPIN (≥6 versus 1-3: 95% CIs: 1.04, 2.97; Wald test, P = 0.021), conditional on the pre-defined predictors.
Flaws in the reporting and interpretation of the findings of abstracts of meta-analyses, as framed by inclusion of SPIN are persistent in orthodontic research, being more prevalent in meta-analyses of observational studies. Consistent, multidirectional efforts should be endorsed to improve the quality of the disseminated research findings.
The objective of this research was to evaluate and compare linear and surface accuracy of dental models fabricated using 3 different vat photopolymerization printing units: digital light synthesis ...(M2 Printer; Carbon, Redwood City, Calif), digital light processing (Juell 3D Flash OC; Park Dental Research, New York, NY), and stereolithography apparatus (Form 2; Formlabs Inc, Somerville, Mass), and a material jetting printing unit: PolyJet (Objet Eden 260VS; Stratasys, Eden Prairie, Minn).
Maxillary and mandibular dental arches of 20 patients with the American Board of Orthodontics Discrepancy Index scores ranging between 10 and 30 were scanned using an intraoral scanner. Stereolithographic files of each patient were printed via the 3-dimensional (3D) printers and were digitized again using a 3D desktop scanner to enable comparisons with the original scan data. One-sample t test and linear regression analyses were performed. To further graphically examine the accuracy between the different methods, Bland-Altman plots were computed. The level of significance was set at P <0.05.
Bland-Altman analysis showed no fixed bias of one approach vs the other, and random errors were detected in all linear accuracy comparisons. When a 0.25 mm tolerance level was deemed acceptable for any positive or negative surface changes, only the models manufactured from digital light processing and PolyJet units showed more than 97% match with the original scans.
The surface area of 3D printed models did not yield an utterly identical match to the original scan data and was affected by the type of printer. The clinical relevance of the differences observed on the 3D printed dental model surfaces requires application-specific judgments.
•3D printed models from 3 units were printed using commercial software.•Statistical evaluations showed no fixed bias of one approach vs the other.•Random errors were detected in all comparisons.•Surface deviations—showed significant differences.•Always consider the degree of surface mismatch in 3D printing of orthodontic models.
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