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Compared with the frequent investigations into the accuracy of digital intraoral scans, studies analyzing digital determinations of jaw relationships based on intraoral scans are scarce.The purpose of this in vitro study was to present an optical 3-dimensional method for analyzing deviations in static occlusion and to compare the accuracy of conventional and digital interocclusal registrations.A Frasaco jaw model was duplicated, articulated, and scanned with a high-precision industrial scanner, and the data were stored in a virtual standard tessellation language (STL) format, which served as the reference model. Fifteen paired mandibular and maxillary models were scanned with a digital intraoral scanner in the completely digital workflow (IOS group). Forty-five paired gypsum casts were poured from polyvinyl siloxane (PVS) impressions and associated with 2 different PVS registration materials. These casts were digitized with a laboratory scanner and grouped as follows (n=15/group): PVS group, conventional Futar D interocclusal record; sPVS group, conventional Futar Scan interocclusal record; and the AIR group, partially digital antagonist scan of the Futar Scan interocclusal record. The axes (X, Y, Z, and XYZ) of each paired model were aligned to those of the reference model by 3-dimensional superimposition, and deviations were calculated. To determine the ideal zero position, a best-fit over the mandibular teeth between the reference model and the actual model was estimated. Next, a second best-fit was determined between the maxillary models to determine the actual position of the mandibular model. The different registration methods were compared with the Mann-Whitney U test (α=.05).In the IOS group, the interocclusal registration caused a mandibular deviation of 0.05 ±0.04 mm (mean ±standard deviation). This fit was better than those of conventional registrations with inserted interocclusal registration materials (PVS group and sPVS group), which caused mean z-axis deviations of 0.41 ±0.46 mm and 0.44 ±0.32 mm (P.001), with the deviations leading to elevation of the mandibular model. The partially digital workflow with a scannable registration material (AIR group) showed significantly larger deviations in the x-axis (0.15 ±0.08 mm; P=.042) compared with the IOS group. No significant difference was observed in the total deviation between the IOS and the AIR groups. Both groups showed significantly smaller deviations than the conventional registration methods (P.001 for the IOS group and P=.023 for the AIR group).In comparison with maxillary and mandibular alignment using conventional interocclusal registration materials, digital interocclusal registrations showed greater accuracy in evaluating complete jaw models and can be recommended for clinical use. Additionally, the partially digital workflow with an antagonist scan of the interocclusal record provided acceptable results.

Purpose Here we aimed to compare two machining strategies regarding the marginal strength of CAD/CAM materials using a hoop-strength test in model sphero-cylindrical dental crowns, coupled with finite element analysis. Materials and Methods Five CAD/CAM materials indicated for single posterior crowns were selected, including a lithium disilicate (IPS e.max® CAD), a lithium (di)silicate (Suprinity® PC), a polymer-infiltrated ceramic scaffold (Enamic®), and two indirect resin composites (Grandio® Blocs and Lava™ Ultimate). A sphero-cylindrical model crown was built on CAD Software onto a geometrical abutment and machined using a Cerec MC XL system according to the two available protocols: rough-fast and fine-slow. Specimens were fractured using a novel hoop-strength test and analyzed using the finite element method to obtain the inner marginal strength. Data were evaluated using Weibull statistics. Results Machining strategy did not affect the marginal strength of any restorative material tested here. Ceramic materials showed a higher density of chippings in the outer margin, but this did not reduce inner marginal strength. IPS e.max® CAD showed the statistically highest marginal strength, and Enamic® and Lava™ Ultimate were the lowest. Grandio® Blocs showed higher performance than Suprinity® PC. Conclusions The rough-fast machining strategy available in Cerec MC XL does not degrade the marginal strength of the evaluated CAD/CAD materials when compared to its fine-fast machining strategy. Depending on the material, resin composites have the potential to perform better than some glass-ceramic materials.

The aim of this study was to compare the trueness of complete- and partial-arch impressions obtained using conventional impression materials and intraoral scanners in vivo. Full-arch impressions were taken using polyether and polyvinylsiloxane. Gypsum casts were digitized using a laboratory scanner (IM, AF). Casts obtained from polyether impressions were also scanned using an industrial blue light scanner to construct 3D reference models. Intraoral scanning was performed using CEREC Omnicam (CO) and Trios 3 (TR). Surface matching software (Atos Professional) enabled to determine the mean deviations (mean distances) from the reference casts. Statistically significant discrepancies were calculated using the Wilcoxon signed-rank test. The mean distance for trueness ranged from 0.005 mm (TR) to 0.023 mm (IM) for the full arch, from 0.001 mm (CO) to 0.068 mm (IM) for the anterior segment, and from 0.019 mm (AF) to 0.042 mm (IM) for the posterior segment. Comparing the anterior vs. the posterior segment, significantly less deviations were observed for anterior with CO (p p p = 0.014), IM vs. CO (p = 0.002), and IM vs. TR (p = 0.001). Full-arch trueness was comparable when using Affinis and the two intraoral scanners CEREC Omnicam and Trios 3. The digital impression devices yielded higher local deviations within the complete arch. Digital impressions of the complete arch are a suitable and reliable alternative to conventional impressions. However, they should be used with caution in the posterior region.Trial registration: Registration number at the German Clinical Trial Register (04.02.2022): DRKS00027988 (https://trialsearch.who.int/).

Purpose Sufficient data are not currently available on how the various geometries of scan bodies and different scan strategies affect the quality of digital impressions of implants. The purpose of this study was to present new data on these two topics and give clinicians a basis for decision making. Materials and methods A titanium master model containing three Nobelreplace Select™ implants (Nobelbiocare Services AG, Zurich, Switzerland) was digitized using an ATOS industrial noncontact scanner. Digitization was repeated three times with different types of scan bodies integrated into the implants: ELOS A/S, nt-trading GmbH, and TEAMZIEREIS GmbH. These three scans served as virtual master models. The titanium master model was then scanned with the TRIOS3© digital intraoral scanner (ELOS A/S, Copenhagen, Denmark), which was used for two different scanning strategies. Strategy A was a one-step procedure that included both the titanium master model and the integrated scan bodies. Strategy B comprised two steps. First, a digital overlay was performed with a scan of the titanium master model without integrated scan bodies. A second scan was performed with the titanium master model and integrated scan bodies. By repeating both strategies 10 times for each type of scan body, 60 scans were generated and the corresponding standard tessellation language data sets overlaid with the corresponding virtual master model. Deviations in the resulting superimpositions were calculated and evaluated separately in the individual axes (x, y, z) and in three-dimensional space (Euclidean distance). Statistical evaluation was performed using the R-project software. Level of significance was determined at p ≤ 0.05. Results With regard to the geometry of the scan bodies, strategy A significantly influenced the accuracy of the digital implant impression in regards to Euclidean distance (p = 0.003). No significant difference was found for strategy B in this context. Comparing the two scan strategies revealed that strategy A achieved significantly higher accuracy overall (p = 0.031). Conclusion The quality of digital intraoral impressions seems to be influenced by both the geometry of the scan body and the scan strategy. For clinical practice, the one-step scan strategy seems beneficial. Furthermore, the scan bodies of ELOS A/S showed a potential clinical advantage.

Journal of oral rehabilitation 49(1), 71-80 (2022). doi:10.1111/joor.13276, Published by Wiley-Blackwell, Oxford [u.a.]

Background: The abrasion behavior of various ceramics is rarely investigated, though it is relevant for the clinical success of such restorations. The aim of this in vivo study was to evaluate the wear of feldspathic-ceramic-veneered zirconium oxide frameworks over a period of at least 10 years.Methods: The abrasion behavior of 15 bridge constructions from 15 different participants was examined after a period of 3, 5, and 10 years using plaster models, which were then subjected to a scanning process on the Atos II industrial scanner and digitized for three-dimensional evaluation of the abrasion by the corresponding software (ATOS Professional 7.6). The individual post-examination models were compared to the baseline model and deviations calculated in the sense of the largest, punctual loss of material in millimeters ("minimal distance"), the average abrasion in millimeters ("mean distance"), and the volume decrease in cubic millimeters ("integrated distance"). Statistical analyses were performed using the Wilcoxon sign rank test or mixed regression models. Multiple testing was considered by Benjamini-Hochberg correction. The significance level was set at 0.05.Results: We found steadily increasing wear of the ceramic. The average volume decrease was significant (P < 0.001) at 3 years and 10 years (-3.25 mm3 and -8.11 mm3, respectively).Conclusions: The results of this study indicate that the rate of volume loss in feldspathic-ceramic-veneered zirconia frameworks in the posterior region increases significantly over time. An increasing frequency of parameters was observed, particularly in the second half of the study period. However, the use of this class of materials can be considered clinically acceptable.This study is registered in DRKS - German Clinical Trials Register with the register number 00021743.

Background: The abrasion behavior of various ceramics is rarely investigated, though it is relevant for the clinical success of such restorations. The aim of this in vivo study was to evaluate the wear of glass-ceramic-veneered zirconium oxide frameworks over a period of at least 10 years.Methods: The abrasion behavior of 15 bridge constructions from 15 different participants was examined after a period of 3, 5, and 10 years using plaster models, which were then subjected to a scanning process on the Atos II industrial scanner and digitized for three-dimensional evaluation of the abrasion by the corresponding software (ATOS Professional 7.6). The individual post-examination models were compared to the baseline model and deviations calculated in the sense of the largest, punctual loss of material in millimeters ("minimal distance"), the average abrasion in millimeters ("mean distance"), and the volume decrease in cubic millimeters ("integrated distance"). Statistical analyses were performed using the Wilcoxon sign rank test or mixed regression models. Multiple testing was considered by Benjamini-Hochberg correction. The significance level was set at 0.05.Results: We found steadily increasing wear of the ceramic. The average volume decrease was significant (P < 0.001) at 3 years and 10 years (-3.25 mm3 and -8.11 mm3, respectively).Conclusions: The results of this study indicate that the rate of volume loss in glass-ceramic-veneered zirconia frameworks in the posterior region increases significantly over time. An increasing frequency of parameters was observed, particularly in the second half of the study period. However, the use of this class of materials can be considered clinically acceptable.

BACKGROUND/OBJECTIVE: In this retrospective study, we aimed to investigate a new 3D evaluation method for evaluating bone regeneration after cystectomy of odontogenic cysts. METHODS: The study included 26 patients who underwent cystectomies between 2012 and 2017 and had received either fillings or non-fillings with autologous iliac crest. Bony regeneration was analyzed using 3D imaging software and comparing identical regions of interest (ROIs) that were determined by exact overlays of the postoperative cone beam computer tomography (CBCT) or computer tomography (CT) images. Outcome measures, including volume changes according to the defect size and configuration, patient age, the entity and distribution of the cysts, were collected. RESULTS: Twenty-six patients (5 women and 21 men) had 30 defects, including nine keratocysts, seven radicular cysts and 14 dentigerous cysts. A total of 73% of the defects were in the mandible. The mean 3D follow-up time was 12 months. According to the 3D evaluation of bony regeneration, the defect size and configuration showed no significant differences between the groups (filled or non-filled with 15 defects per group). CONCLUSIONS: By establishing a standardized 3D method for evaluating bone regeneration, healing can be better monitored and evaluated.

Aim This study evaluates the early volumetric changes after buccal soft tissue contour augmentation around implants with a porcine collagen matrix (CM) vs. the subepithelial connective tissue graft (SCTG) from the palate. Materials and methods 14 patients were enrolled after early implant placement with simultaneous contour augmentation and persistent buccal tissue deficits. At implant exposure, buccal soft tissues were thickened with the CM (n = 7) or the SCTG (n = 7). Impressions were taken before and after surgery, after ten days, one, three and six months. Impressions were digitized and augmented regions 3D evaluated (soft tissue volume (mm3, %)/thickness (mm)). Results Volume increase (mm3) after 6 months was 19.56 ± 8.95 mm3 (CM) and 61.75 ± 52.69 mm3 (SCTG) (insignificant, p = .058). In percentage, this was a volume loss of the initially augmented soft tissue volume (100%) of 81.76% in the CM group and 56.39% in the SCTG group (6 months). The mean soft tissue thickness increase (mm) in the buccal contour after 6 months was 0.30 ± 0.16 mm (CM) and 0.80 ± 0.61 mm (SCTG) (insignificant, p = .071). Conclusion The early healing phase is associated with a significant volume loss of the soft tissues. The SCTG shows insignificant superiority compared to the CM.

Purpose The use of a surgical template is a well-established method in advanced implantology. In addition to conventional fabrication, computer-aided design and computer-aided manufacturing (CAD/CAM) work-flow provides an opportunity to engineer implant drilling templates via a three-dimensional printer. In order to transfer the virtual planning to the oral situation, a highly accurate surgical guide is needed. The aim of this study was to evaluate the impact of the fabrication method on the three-dimensional accuracy. Materials and methods The same virtual planning based on a scanned plaster model was used to fabricate a conventional thermo-formed and a three-dimensional printed surgical guide for each of 13 patients (single tooth implants). Both templates were acquired individually on the respective plaster model using an optical industrial white-light scanner (ATOS II, GOM mbh, Braunschweig, Germany), and the virtual datasets were superimposed. Using the three-dimensional geometry of the implant sleeve, the deviation between both surgical guides was evaluated. Results The mean discrepancy of the angle was 3.479° (standard deviation, 1.904°) based on data from 13 patients. Concerning the three-dimensional position of the implant sleeve, the highest deviation was in the Z-axis at 0.594 mm. The mean deviation of the Euclidian distance, dxyz, was 0.864 mm. Conclusion Although the two different fabrication methods delivered statistically significantly different templates, the deviations ranged within a decimillimeter span. Both methods are appropriate for clinical use.

Accurate virtual implant models are a necessity for the fabrication of precisely fitting superstructures.The purpose of this in vitro study was to evaluate different methods with which to build an accurate virtual model of a 3-dimensional implant in the oral cavity; this model would then be used for iterative computer-aided design and computer-aided manufacturing (CAD-CAM) procedures.A titanium master model with 3 rigidly connected implants was manufactured and digitized with a noncontact industrial scanner to obtain a virtual master model. Impressions of the master model with the implant position locators (IPL) were made using vinyl siloxanether material. The impressions were scanned (Impression scanning technique group). For the transfer technique and pick-up technique groups (each group n=20), implant analogs were inserted into the impression copings, impressions were made using polyether, and casts were poured in Type 4 gypsum. The IPLs were screwed into the analogs and scanned. To compare the virtual master model with each virtual test model, a CAD interactive software, ATOS professional, was applied. The Kruskal-Wallis test was subsequently used to determine the overall difference between groups, with the Mann-Whitney U test used for pairwise comparisons. Through Bonferroni correction, the α-level was set to .017.The outcome revealed a significant difference among the 3 groups (P.01) in terms of accuracy. With regard to total deviation, for all axes, the transfer technique generated the greatest divergence, 0.078 mm (±0.022), compared with the master model. Deviation with the pick-up technique was 0.041 mm (±0.009), with impression scanning generating the most accurate models with a deviation of 0.022 mm (±0.007).The impression scanning method improved the precision of CAD-CAM-fabricated superstructures.

Deformation of the mandible presents a major challenge for many dentists, both in conventional prosthetic supraconstructions and in complex implant restorations. This study aimed to evaluate the three-dimensional (3D) deformation of the mandible in vivo with scannable impression material and an industrial optical scanner.In the present study, 20 female and 20 male subjects were examined. In each case, two impressions were made with polyvinylsiloxane: one with the mouth slightly open, and a second with the mouth wide open. The impressions were digitized with an industrial optical scanner and transformed into a virtual model. The two corresponding models were digitally superimposed over all the teeth. Then, an individual local coordinate system was assigned to each individual tooth. Subsequently, a best-fit procedure was performed for each individual tooth. Finally, the open- and closed-mouth models were compared by calculating the differences and rotations in the individual axes. This procedure was performed individually for each tooth.The mean deviations in the x-, y-, and z-coordinates ranged from 0.011 mm at the canines to 0.232 mm at the molars. Larger discrepancies were observed in the female subjects than in the male subjects; however, these differences were not statistically significant.The results demonstrated that the posterior region of the mandible deformed when the mouth was maintained in a wide-open position. Therefore, this position should be avoided when performing dental impressions. Moreover, potential negative consequences of this mandibular deformation should be taken into consideration when planning wide-span fixed dental restorations.

Objectives This study’s hypothesis was to evaluate differences of the occlusal wear rate for monolithically fabricated lithium disilicate and hand-veneered zirconia crowns in-vivo. Furthermore, a comparison of the materials’ clinical performance according to CDA criteria was investigated. Methods A total number of 15 patients in the need of full-coverage ceramic fixed dental prosthesis on molars were treated with two crowns each (n = 30), randomly assigned on the contralateral sides made of monolithic IPS e.max CAD (n = 15) and IPS e.max Ceram hand-veneered zirconia (n = 15). Clinical examination was conducted, silicone impressions were taken and plaster models fabricated at the day of crown insertion (baseline) and after 1, 2 and 3 years. The abrasion rate was digitally investigated: after model digitization with the industrial scanner Atos II, each follow-up model was superimposed with the baseline model. The wear was evaluated as the difference between two scans in terms of maximum vertical loss [mm], average decrease [mm] and volume loss [mm³]. For statistical analysis, the Mann–Whitney U test was performed and significance was set to less than 0.05. Results IPS e.max CAD crowns showed a volume loss of −0.68 mm³ after three years, while IPS e.max Ceram hand-veneered zirconia crowns showed a volumetric wear of −0.75 mm³ at the same point of time. However, no significant differences were found between both materials regarding the 3 evaluated wear parameters. The survival rate for both materials was 100 % and the clinical performance outcome was good to excellent. Conclusion The two investigated materials for ceramic fixed dental prostheses showed similar wear rates and clinical performance over an in-vivo use of 3 years. Clinical Significance Ceramic restorations are subject to occlusal wear over time due to the natural masticatory process. Both monolithic lithium disilicate and glass-ceramic veneered zirconia copings showed clinically satisfactory results over 3 years in-situ. In terms of abrasion, they are equally well suited for clinical use.

Purpose Three-dimensional (3D) radiological imaging plays an important role in surgical planning used in modern dentistry. The aim of this study was to optimize imaging parameters with a special focus on voxel size and scan time. Material and methods A virtual 3D master model of a macerated human skull was generated using an industrial optical noncontact white light scanner. The skull was X-rayed with cone-beam computed tomography that was applied using different settings for voxel size and acquisition time (voxel edge length of 0.3 mm, scan times 4.8 s and 8.9 s; voxel edge length of 0.2 mm, scan times 14.7 s and 26.9 s). The scan was repeated 10 times at each setting. The CBCT scans were converted into 3D virtual models (actual value), which were superimposed with the 3D master model (reference value) to detect absolute differences. Results The mean value of deviation increased with increasing voxel size and decreasing scan time. For a voxel edge length of 0.3 mm, the mean values of deviation were 0.33 mm and 0.22 mm with scan times of 4.8 s and 8.9 s, respectively. For a voxel edge length of 0.2 mm, the mean deviations were 0.16 mm and 0.14 mm with scan times of 14.7 s and 26.9 s, respectively. Conclusions When using small voxel sizes, the scan time does not have a significant impact on image accuracy and therefore the scan time can be shortened. However, for larger voxel sizes, shorter scan times can lead to increased inaccuracy.

Objectives Three-dimensional radiological imaging data play an increasingly role in planning, simulation, and navigation in oral and maxillofacial surgery. The aim of this study was to establish a new, highly precise, in vitro measurement technology for the evaluation of the geometric accuracy down to the micrometric range of digital imaging data. Material and methods A macerated human mandible was scanned optically with an industrial, non-contact, white light scanner, and a three-dimensional (3D) model was obtained, which served as a master model. The mandible was then scanned 10 times by cone beam computed tomography (CBCT), and the generated 3D surface bone model was virtually compared with the master model. To evaluate the accuracy of the CBCT scans, the standard deviation and the intraclass coefficient were determined. Results A total of 19 measurement points in 10 CBCT scans were investigated, and showed an average value of 0.2676 mm with a standard deviation of 0.0593 mm. The standard error of the mean was 0.0043 mm. The intraclass correlation coefficient (ICC) within the 10 CBCT scans was 0.9416. Conclusions This highly precise measuring technology was demonstrated to be appropriate for the evaluation of the accuracy of digital imaging data, down to the micrometric scale. This method is able to exclude human measurement errors, as the software calculates the superimposition and deviation. Thus inaccuracies caused by measurement errors can be avoided. This method provides a highly precise determination of deviations of different CBCT parameters and 3D models for surgical, navigational, and diagnostic purposes. Thus, surgical procedures and the post-operative outcomes can be precisely simulated to benefit the patient.

Fur den langfristigen Erfolg von Implantatversorgungen spielt die Passgenauigkeit der Suprakonstruktion eine wesentliche Rolle. Die Weiterentwicklung der CAD / CAM-Technologie ermoglicht die Fertigung von prazise sitzenden Stegen. Dabei kommt es besonders auf das moglichst exakte Ubertragen der Implantatposition in ein virtuelles Modell an. Neben der Abformmethode liefert auch die Gipsmodellherstellung eine mogliche Fehlerquelle. Deshalb wurde in dieser Studie die konventionelle Polyetherabformung mit dem direkten Scannen des Abdruckmaterials verglichen.

Advanced imaging modalities, such as multi-slice computed tomography (MSCT) and cone beam computed tomography (CBCT), greatly facilitate diagnostic medicine. In radiological research, it is important to know how accurately a scanned object is visualized, and whether the methodology leads to image distortion. The objective of this study was to evaluate whether formalin fixation impacted the accuracy of virtual 3D bone models generated via CBCT and MSCT using a software-based evaluation method that excluded human measurement errors. A head specimen, with and without formalin preservation, was subjected to MSCT and CBCT scans using the manufacturers’ predefined scanning protocols. Digital models of the lower jaw were constructed and superimposed with a master model generated based on optical scanning with an industrial non-contact scanner. Means and standard deviations were calculated to assess accuracy, and a t test was used for comparisons between the fixed and unfixed specimens. The extent of discrepancy between the fixed and unfixed specimens was analyzed using a total of 200 points (n = 200) in each specimen state. The mean deviation between states was 0.01 mm for MSCT (at both 80 and 140 kV). Mean values from CBCT at 0.4 voxel did not differ between states. Our results suggest that formalin fixation of an anatomical specimen does not substantially affect the accuracy of a three-dimensional image generated with CBCT and MSCT. Thus, fixed specimen can be used in future investigations of 3D models without concerns regarding the accuracy.

Orthodontists influence dental occlusion directly. To suggest any link between dental occlusion and body posture is highly contentious, as evidenced by the literature. Rasterstereography, an optical technique that enables three-dimensional (3D) body measurements to be collected, has not yet been used to impartially examine whether different occlusal positions could instantaneously alter spine and body posture. We therefore set out to use this technique to nonsubjectively evaluate this question under static conditions. Optical body scans were collected for 44 subjects, using the Diers formetric 4D system, for seven different mandible positions. In total, ten spinal and body posture parameters were assessed (trunk inclination, trunk imbalance, pelvic tilt, pelvic torsion, fleche cervicale, fleche lombaire, kyphotic angle, lordotic angle, surface rotation, and lateral deviation) for each mandible position and compared with scans performed with habitual intercuspation (HIC). Significant body posture deviations were found for the fleche cervicale (position of the mandible: right eccentrically), fleche lombaire (positions of the mandible: physiologic rest position, cotton rolls on both sides, bite elevation 1 mm), and the kyphotic angle (positions of the mandible: cotton rolls on both sides, right eccentrically). No other significant differences were detected. Data for the parameters that varied with different dental occlusions generated high standard deviations. Therefore, within the limitations of this pilot study, we could not conclusively associate dental occlusion to an instantaneous impact on the tested parameters. The posture changes that we detected could also have arisen from individual neuromuscular compensation; a possibility that must now be ruled-in, or out, by further research studies with a higher number of subjects.

Objectives Multi-slice computed tomography (MSCT) and cone beam computed tomography (CBCT) are indispensable imaging techniques in advanced medicine. The possibility of creating virtual and corporal three-dimensional (3D) models enables detailed planning in craniofacial and oral surgery. The objective of this study was to evaluate the impact of different scan protocols for CBCT and MSCT on virtual 3D model accuracy using a software-based evaluation method that excludes human measurement errors. Material and methods MSCT and CBCT scans with different manufacturers' predefined scan protocols were obtained from a human lower jaw and were superimposed with a master model generated by an optical scan of an industrial noncontact scanner. To determine the accuracy, the mean and standard deviations were calculated, and t-tests were used for comparisons between the different settings. Results Averaged over 10 repeated X-ray scans per method and 19 measurement points per scan (n = 190), it was found that the MSCT scan protocol 140 kV delivered the most accurate virtual 3D model, with a mean deviation of 0.106 mm compared to the master model. Only the CBCT scans with 0.2-voxel resolution delivered a similar accurate 3D model (mean deviation 0.119 mm). Conclusion Within the limitations of this study, it was demonstrated that the accuracy of a 3D model of the lower jaw depends on the protocol used for MSCT and CBCT scans.