Evaluating the influence of palate scanning on the accuracy of complete-arch digital impressions - an in vitro study.

OBJECTIVES: To assess the impact of including the palate and the number of images recorded during intraoral digital scanning procedure on the accuracy of complete arch scans. METHODS: An experienced operator conducted 40 digital scans of a 3D printed maxillary model and divided them into two groups: 20 with inclusion of the palate (PAL) and 20 without (NPAL). Each set of scans was performed using an intraoral scanner (IOS) (Trios 5; 3Shape A/S; Copenhagen, Denmark). The resulting STL files were imported into the Geomagic Control X software (3D Systems, Rock Hill, SC, USA) for accuracy comparison. A reference STL file was created using a 3Shape E3 laboratory scanner (3Shape Scanlt Dental 2.2.1.0; Copenhagen, Denmark). The number of images captured was recorded during the scanning procedure. RESULTS: In the case of the right side no statistically significant difference in trueness was detected (84 µm ± 45.6 for PAL and 80.4 ± 40.4 µm for NPAL). In the case of the left side no significant difference in trueness was observed (215.1 ± 70.2 µm for PAL and 233.9 ± 70.7 µm for NPAL). In the case of the arch distortion a statistically significant difference in trueness was seen between the two types of scans (135.3 ±71.9 µm for PAL and 380.4 ± 255.1 µm for NPAL). The average number of images was 831.25, and 593.8 for PAL and NPAL, respectively. CONCLUSIONS: Scanning of the palatal area can significantly improve the accuracy of dental scans in cases of complete arches. In terms of the number of images, based on the current results, obvious conclusions could not be drawn, and further investigation is required. CLINICAL SIGNIFICANCE: Scanning the palate may be beneficial for improving the accuracy of intraoral scans in dentate patients. Consequently, this should be linked to an appropriate scanning strategy that predicts palatal scanning.

The effect of generation change on the accuracy of full arch digital impressions.

PURPOSE: This study is aimed to evaluate the effect of generation change on accuracy of IOSs on full-arch scans and the inter-operator reliability. METHODS: In this study, 6 different IOS were tested: 3Shape Trios 3 (20.1.2.), 3Shape Trios 4 (20.1.1.), Medit i500 (2.3.6.), Medit i700 (2.4.6.), Planmeca Emerald (6.0.1.) and Planmeca Emerald S (6.0.1.). Eighteen dental students, inexperienced in scanning, took part in this study as operators. Each operator made 10 digital impressions; altogether, 30 impressions were made by each scanner. The 30 STL files were imported to the Geomagic Control X program, where they were compared to a reference STL file; the surface point's deviation of the full arch and the distance between the second molars' distobuccal cusps were measured, the inter-operator reliability was also investigated. RESULTS: A significant increase in accuracy was found between Trios 3 and 4 in the case of both parameters and between Medit i500 and i700 in the case of full arch. There was no significant difference between Planmeca generations. In case of the inter-operator reliability no significant difference was detected. CONCLUSION: Within this current study's limitation, it can be concluded that surface digitalization's accuracy can be modified with generation changes and that digital technology is less technique sensitive than traditional impression taking.

Comparison of the learning curve of intraoral scanning with two different intraoral scanners based on scanning time.

BACKGROUND: The appearance of intraoral scanners (IOSs) in dental offices was an important milestones for the digital innovations in dentistry. Knowing the learning curve for intraoral scanning is crucial, because it can serve as a guideline for clinicians before buying a new IOS. The aim of the present in vivo study was to determine the learning curve required by dental students for intraoral scanning with the 3Shape Trios 4 IOS and the CEREC Primescan IOS, based on scanning time. METHODS: A total of 20 dental students with no previous experience in intraoral scanning participated in the present study. 10 students scanned with Trios 4® IOS (TRI) and 10 students took digital impressions with Primescan® IOS (CER). Every student created 15 digital impressions from patients. Prior to taking the impressions, theoretical and practical education was provided. The total scanning time included the upper and lower arches as well as bite registration, for which average values were calculated. Statistical analysis was performed using the Stata package with a mixed-effects generalized least squares regression models. RESULTS: The average total scanning times were the following: TRI - 205 s for the 1st impression, 133.6 s for the 15th, CER - 289.8 s for the 1st impression, 147 s for the 15th. The model-based estimate of the difference between the two in case of TRI was 57.5 s, and in CER was 144.2 s which is a highly significant improvement in both cases (P < 0.0001). The slope of the scanning time vs. learning phase curve gradually approached flatness, and maintained a plateau: TRI - from the 11th measurement and CER - from the 14th measurement onward. CONCLUSIONS: Given the limitations of the present study, we found difference between the learning curve of scanner types which are operate various principle of imaging. In case of the TRI fewer digital impressions (11 repeating) were sufficient to reach the average scanning time of an experienced user than using CER (14 repeating). TRIAL REGISTRATION: The permission for this study was given by the University Ethics Committee of Semmelweis University (SE RKEB number: 184/2022).

Therapy for Temporomandibular Disorders: 3D-Printed Splints from Planning to Evaluation.

INTRODUCTION: This article describes the authors' digital workflow-based method for fabricating intraoral occlusal splints, from planning to the evaluation phase. MATERIALS AND METHODS: In our protocol, first, we had a registration phase. This included taking digital impressions, determining the centric relation (CR) position with the deprogrammer Luci Jig, and using the digital facebow for measuring the individual values. The laboratory phase was next, which included planning and manufacturing with a 3D printer. The last phase was delivery, when we checked the stability of the splint and adjusted the occlusal part. RESULT: The average cost is lower for a fully digital splint than for conventional methods. In terms of time, there was also a significant difference between the classic and digital routes. From a dental technical point of view, the execution was much more predictable. The printed material was very rigid and, therefore, fragile. Compared to the analog method, the retention was much weaker. CONCLUSION: The presented method permits time-efficient laboratory production, and may also be performed chairside in a dental office. The technology is perfectly applicable to everyday life. In addition to its many beneficial properties, its negative properties must also be highlighted.

The impact of software updates on accuracy of intraoral scanners.

BACKGROUND: Digital workflow is showing an increasing tendency in everyday dentistry. Accuracy is essential during digital dental workflows for all indication areas. The present study aimed to evaluate the effect of software updates on the accuracy of intraoral scanner (IOS) devices. METHODS: 3Shape Trios 3 Pod with software versions 18.1.2. (TRI3_1) and 20.1.2. (TRI3_2); 3Shape Trios 4 Move, version 19.2.2. (TRI4_1); and 3Shape Trios 4 Pod, version 20.1.1. (TRI4_2) were used to take direct optical impressions from a polymethyl methacrylate (PMMA) full arch reference model with prepared teeth (FDI 11,14,17 for crowns and FDI 26 for onlay) and an edentulous region (between FDI 14 and 17). The scanners were used eight times; STL files were imported into Geomagic Control X for accuracy assessment by comparing them to a reference data set created by an industrial high-precision scanner (AICON SmartScan-3D C5). The average deviation of the surface points was calculated in three locations: across a full arch (Parameter 1), the region of a four-unit bridge (Parameter 2), and a single prepared abutment (Parameter 3). RESULTS: In parameter 1 and 2, the newest model with the latest software (TRI4_2) reached the highest accuracy (31.06 ± 5.24 µm and 21.69 ± 7.50 µm). In parameter 3, an older generation scanner running legacy software produced the highest accuracy: TRI4_1, 11.75 ± 0.35 µm. CONCLUSION: Appropriate software updates can significantly increase the trueness and precision of intraoral scanner devices. With updated software, the older generation can match the accuracy level of latest equipment.

The use of Trojan-horse drug delivery system in managing periodontitis.

The aim of this review is to evaluate the possibility of delivering a silver-acid complex via a Trojan-horse mechanism for managing periodontits. We theroised that the complex could be an effective treatment option for bacterial inflammatory processes in the oral cavity. Searches were conducted using MEDLINE, Embase, Web of Science Core Collection, and Google Scholar search engines. We also reviewed several reference lists of the included studies or relevant reviews identified by the search. By using Medical Subject Headings (MeSH) terminology, a comprehensive search was performed for the following keywords: silver, folic acid, periodontitis, macrophages, Trojan-horse mechanism, toxicity, and targeting. Using the keywords mentioned earlier, we selected 110 articles and after appropriate elimination the review was written based on 37 papers. Accordingly the we noted that silver isons were an effective approach to kill oral pathogens. Secondly the Trojan-horse mechanism. could be used by macrophages (as the Trojan horse) to deliver silver ions in large quantities to the inflammatory focus to kill the periodontopathogens. The Trojan-horse mechanism has never been described in the field of dentistry before. The proposed novel approach using the principle of Trojan Horse delivery of drugs/chemicals could be used to manage oral inflammatory conditions. This method can be used to supplement regular treatments.

Digital intraoral scanner devices: a validation study based on common evaluation criteria.

BACKGROUND: The evolution of intraoral scanners (IOSs) is rapid, and new IOSs appear on the market with different properties depending on the manufacturers. There is no uniform rating system based on a defined set of aspects that has reported in the literature that can be used to compare these devices. This validation study aimed to compare different IOSs based on objective and comprehensive parameters. METHODS: In this study, 12 different IOSs were examined. The IOSs that were tested in this study in order of their delivery included the 3Shape Trios 3 Pod®, Planmeca Emerald®, Straumann DWIO®, GC Aadva®, iTero Element 2®, CEREC Primescan®, Medit i500®, 3Shape Trios 4 Move®, Carestream CS3600®, 3Shape Trios 4 Pod®, Carestream CS3700®, and Planmeca Emerald S®. IOSs were evaluated in four different ways: (a)summary chart, (b)comparative assessment, (c)data based on in vitro measurements and (d)accuracy measurements. A scoring system was created to enable an objective rating of IOSs. RESULTS: The differences among IOSs were demonstrated in point scores (summary chart[max. 10 points] + weight of IOSs[max. 2.5 points] + circumference of IOSs[max. 2.5 points] + in vitro scanning time[max. 2.5 points] + pauses in data capture[max. 2.5 points] + accuracy[max. 10 points] = summary[max. 30 points]). Trios 4 Pod achieved the greatest cumulative score (23.37 points), furthermore it earned the highest points for summary chart and scanning speed. Regarding scanning continuity, the best-performing IOSs, which tied at identical point scores, were the Trios 3 and 4 Pod, Trios 4 Move, iTero Element 2, CS3600 and CS3700. The most accurate IOS was the CEREC Primescan, although it earned the lowest points of the comparative assessment (heaviest IOS). GC Aadva scored 5.73 points of a maximum of 30 points, which was the poorest result in this study. CONCLUSION: The scoring system reflects the differences among IOS devices based on the evaluated objective parameters and can be used to help clinicians select the right IOS device. The new generations of IOSs have more special properties, and their accuracy is higher than the previous versions. Trial registration The permission for this study was granted by University Ethics Committee of Semmelweis University (SE RKEB number:108/2019).

Comparing the effectiveness of shade measurement by intraoral scanner, digital spectrophotometer, and visual shade assessment.

OBJECTIVE: Trios3 (3Shape, Denmark) intraoral scanner is complete with a tooth shade measurement function, but there is limited information about its efficacy. This in vivo study aimed to evaluate this function in relation to visual and spectrophotometric shade determination. MATERIALS AND METHODS: Ten dental students from Semmelweis University determined tooth shade for 10 volunteers using Vita A1-D4 (VC) and Vita Linearguide 3D-Master (LG) guides, Vita Easyshade spectrophotometer (ES) and Trios 3 intraoral scanner (TR). First and last patient was always the same (Patient R). Intrapersonal repeatability was calculated. Four selected shades of each tooth were presented to student, supervisor, and patient to select best match. Selection percentages were calculated. The supervisor's best match was the reference (∆E00 ). RESULTS: Median ∆E00 of Patient R: TR 1.09; VC 1.5; ES 2.35; LG 3.1. The percentages of best match: VC 16.7%.; TR 21.64%; ES 26.58%; LG 34.08%. Median ∆E00 of students' and supervisor's best match: LG 2.73; ES 4.29; TR 4.29; VC 16.35. TR was the most repeatable. The most "best-match shade tabs" were selected using LG. VC shade tabs was the least consistent with the examined teeth. CONCLUSIONS: TR can be used for shade selection with a 3D-Master tooth color system with visual verification. CLINICAL SIGNIFICANCE: Correct tooth shade determination is one of the most important step in making esthetic restorations. New shade matching systems have been developed to surpass the visual method of shade determination. There are new intraoral scanners with built-in shade measurement functions. Digital shade determination methods are more independent from the environmental circumstances, and with intraoral scanners, it is easy to measure the tooth shade by taking a digital impression at the same time. These new devices may be a reliable alternative method for shade selection with visual verification.

Learning curve of digital intraoral scanning - an in vivo study.

BACKGROUND: The spread of digital technology in dentistry poses new challenges and sets new goals for dentists. The aim of the present in vivo study was to determine the learning curve of intraoral scanning described by (1) scanning time and (2) image number (count of images created by intraoral scanner during the scanning process). METHODS: Ten dental students of Semmelweis University took part in the study. Dental students took digital study impressions using a 3Shape Trios 3® (3Shape, Copenhagen, Denmark) intraoral scanning device. Each student took 10 digital impressions on volunteers. Volunteer inclusion criteria included full dentition (except for missing third molars) and no prosthetic/restorative treatment. Digital impression taking was preceded by tuition consisting of both theoretical education and practical training. Digital impressions were taken of the upper and lower arches, and the bite was recorded according to the manufacturer's instructions. Total scanning times and image numbers were recorded. RESULTS: The difference in scanning time between the first and the tenth digital impressions was significant (p = 0.007). The average scanning time for the first impressions was 23 min 9 s; for the tenth impressions, it was 15 min 28 s. The difference between the scanning times of the first and the tenth procedures was 7 min 41 s. The average image count for the first impressions was 1964.5; for the tenth impressions, it was 1468.6. The image count difference between the first and the tenth procedures was 495.9. The image count versus sequential number of measurement curve shows an initial decreasing tendency followed by a trough around the sixth measurement and a final increasing phase. CONCLUSION: Our results indicate an association between the sequential number of measurements and the outcome variables. The drop in scanning time is probably explained by a practice effect of repeated use, i.e. the students learned to move the scanning tip faster. The image count first showed a decreasing tendency, and after the sixth measurement, it increased; there was no consistent decline in mean scan count. Shorter scanning times are associated with poorer coverage quality, with the operator needing to make corrections by adding extra images; this manifests as the time function of image counts taking an increase after the sixth measurement.