Digital Workflow to Merge an Intraoral Scan and CBCT of Edentulous Maxilla: A Technical Report

Full digital workflow of a 2-piece obturator with polyetherketoneketone in a patient with maxillectomy and trismus: A clinical and laboratory report

The computer-aided design and computer-assisted manufacturing of a 2-piece definitive palatal obturator 3D printed from polyetherketoneketone and 2 acrylic resins with a fully digital workflow are presented for a patient who was diagnosed with adenoid cystic carcinoma and who developed severely limited mouth opening after surgery and radiotherapy. The 18-month follow-up period revealed satisfactory function, tissue compatibility, retention, and esthetics for this patient with a maxillectomy and severe trismus.

Feasibility of using an intraoral scanner for a complete arch digital scan, part 2: A comparison of scan strategies

STATEMENT OF PROBLEM

Various strategies for intraoral scanners (IOSs) can be used to scan the oral cavity. However, research on the scan range that can be clinically is lacking.

PURPOSE

The purpose of this in vitro study was to compare the 3-dimensional (3D) distortion of complete arch scans as part of the scan strategy and analyze the clinically recommended scan range.

MATERIAL AND METHODS

A computer-aided design (CAD) reference model was obtained with an industrial scanner. A CAD test model was obtained by using 6 IOSs (TRIOS2, TRIOS3, CS3500, CS3600, i500, and Primescan) to apply 2 scan strategies and 2 dental laboratory scanners (DOF and E1) (N=15). All the teeth were segmented in the reference model by using 3D inspection software (Geomagic control X). The 3D analysis was performed by aligning the test model to the reference model and evaluating the root mean square values of all segmented teeth. The Mann-Whitney U-test was performed for a statistical comparison of the 2 scan strategies (α=.05), the Kruskal-Wallis test (α=.05) was used to compare the scanners, and the Mann-Whitney U-test and Bonferroni correction method were used as post hoc tests (α=.0017).

RESULTS

The 8 scanners obtained significant differences in the root mean square values of all teeth (P<.001). The root mean square value of IOSs increased from the left maxillary second molar to the right maxillary second molar. The difference in the 2 scan strategies showed different patterns depending on the IOS.

CONCLUSIONS

Scan strategy 2 improved the accuracy of the IOSs. TRIOS2 and CS3500 are for single crowns; TRIOS3, CS3600, and i500 are for short-span prostheses; and Primescan is for long-span prostheses.

Immediate vs. Delayed Placement of Immediately Provisionalized Self-Tapping Implants: A Non-Randomized Controlled Clinical Trial with 1 Year of Follow-Up

This study aimed to examine the clinical and esthetic outcomes of immediately provisionalized self-tapping implants placed in extraction sockets or healed edentulous ridges one year after treatment. Sixty patients in need of a single implant-supported restoration were treated with self-tapping implants (Straumann BLX) and immediate provisionalization. The implant stability quotient (ISQ) and insertion torque were recorded intraoperatively. After one year in function, the implant and prosthesis survival rate, pink esthetic score (PES), white esthetic score (WES), and marginal bone levels (MBL) were assessed. Sixty patients received 60 self-tapping implants. A total of 37 implants were placed in extraction sockets and 23 in edentulous ridges, and then all implants were immediately provisionalized. All implants achieved a high implant stability with a mean insertion torque and ISQ value of 58.1 ± 14.1 Ncm and 73.6 ± 8.1 Ncm, respectively. No significant differences were found between healed vs. post-extractive sockets (p = 0.716 and p = 0.875), or between flap vs. flapless approaches (p = 0.862 and p = 0.228) with regards to the insertion torque and ISQ value. Nonetheless, higher insertion torque values and ISQs were recorded for mandibular implants (maxilla vs. mandible, insertion torque: 55.30 + 11.25 Ncm vs. 62.41 + 17.01 Ncm, p = 0.057; ISQ: 72.05 + 8.27 vs. 76.08 + 7.37, p = 0.058). One implant did not osseointegrate, resulting in an implant survival rate of 98.3%. All implants achieved PES and WES scores higher than 12 at the 1-year follow-up. The clinical use of newly designed self-tapping implants with immediate temporization was safe and predictable. The implants achieved a good primary stability, high implant survival rate, and favorable radiographic and esthetic outcomes, regardless of the immediate or delayed placement protocols.

An overview of three-dimensional imaging devices in dentistry

OBJECTIVE

To review four types of three-dimensional imaging devices: intraoral scanners, extraoral scanners, cone-beam computed tomography (CBCT), and facial scanners, in terms of their development, technologies, advantages, disadvantages, accuracy, influencing factors, and applications in dentistry.

METHODS

PubMed (National Library of Medicine) and Google Scholar databases were searched. Additionally, the scanner manufacturers' websites were accessed to obtain relevant data. Four authors independently selected the articles, books, and websites. To exclude duplicates and scrutinize the data, they were uploaded to Mendeley Data. In total, 135 articles, two books, and 17 websites were included.

RESULTS

Research and clinical practice have shown that oral and facial scanners and CBCT can be used widely in various areas of dentistry with high accuracy.

CONCLUSION

Although further advancement of these devices is desirable, there is no doubt that digital technology represents the future of dentistry. Furthermore, the combined use of different devices may bring dentistry into a new era. These four devices will play a significant role in clinical utility with high accuracy. The combined use of these devices should be explored further.

CLINICAL SIGNIFICANCE

The four devices will play a significant role in clinical use with high accuracy. The combined use of these devices should be explored further.

Accuracy of Computer-Assisted Flapless Implant Placement by Means of Mucosa-Supported Templates in Complete-Arch Restorations: A Systematic Review

The aim of this study was to systematically review the current scientific literature regarding the accuracy of fully guided flapless implant positioning for complete-arch rehabilitations in edentulous patients and to assess if there was any statistically significant correlation between linear deviation at shoulder point, at apex point and angular deviation. The electronic and manual literature search of clinical studies was carried out using specified indexing terms. A total of 13 studies were eligible for qualitative analysis and 277 edentulous patients were rehabilitated with 1556 implants patients by means of fully guided mucosa-supported template-assisted flapless surgery. Angular deviation was 3.42° (95% CI 2.82–4.03), linear deviation at shoulder point 1.23 mm (95% CI 0.97–1.49) and linear deviation at apex point 1.46 mm (95% CI 1.17–1.74). No statistically significant correlations were found between the linear and angular deviations. A statistically significant correlation was found between the two linear deviations (correlation coefficient 0.91) that can be summarized by the regression equation y = 0.03080 + 0.8254x. Computer-assisted flapless implant placement by means of mucosa-supported templates in complete arch restorations can be considered a reliable and predictable treatment choice despite the potential effects that flapless approach could bring to the overall treatment.

Influence of Implant Scanbody Wear on the Accuracy of Digital Impression for Complete-Arch: A Randomized In Vitro Trial

The aim of this study was to evaluate the influence of implant scanbody (ISB) wear on the accuracy of digital impression for complete-arch. A polymethylmethacrylate (PMMA) edentulous mandibular model with four internal hexagonal interlocking conical connections was scanned with an extraoral optical scanner to achieve a reference file. Four cylindrical polyetheretherketone (PEEK) ISBs were scanned 30 times with IOS, and the test files were aligned to the reference file with a best-fit algorithm. For each analog linear (ΔX, ΔY and ΔZ-axis) and angular deviations (ΔANGLE) were assessed. Euclidean distance (ΔEUC) was calculated from the linear deviation, reporting a mean of 82 µm (SD 61) ranging from 8 to 347 µm. ΔANGLE error mean was 0.33° (SD 0.20), ranging from 0.02 to 0.92°. From a multivariate analysis, when ΔEUC was considered as a response variable, a significant influence of ISB wear by scan number in interaction to position for implant 3.6 was identified (p < 0.0001); when ΔANGLE was considered as a response variable, a significant effect of position 3.6 was recorded ((p < 0.0001). The obtained results showed that the ISB wear negatively influenced the accuracy of IOS, suggesting that ISB base wear could be detrimental for the seating of ISBs on angulated implants.

The Digital Clone: Intraoral Scanning, Face Scans and Cone Beam Computed Tomography Integration for Diagnosis and Treatment Planning

The purpose of this article is to synthesize different technologies that are available for the creation of a virtual patient, "the digital clone" because the data can be used for diagnosis as well as treatment planning. The role of facial scans, 3-dimensional intraoral scans as well as the cone beam computed tomography in the creation of a digital clone is discussed in detail. A step-by-step guide is created for the reader for integration of the intraoral scan data with the cone beam computed tomography Dicom data to create a digital clone.

Dental software classification and dento-facial interdisciplinary planning platform

OBJECTIVE

Despite all advantages provided by the digital workflow, its application in clinical practice is still more focused on device manufacturing and clinical execution than on treatment planning and communication. The most challenging phases of treatment, comprehensive planning, diagnosis, risk assessment, and decision-making, are still performed without significant assistance from digital technologies. This article proposes a new dental software classification based on the digital workflow timeline, considering the moment of patient's case acceptance as key in this classification, and presents the ideal software tools for each phase.

CLINICAL CONSIDERATIONS

The proposed classification will help clinicians and dental laboratories to choose the most appropriate software during the treatment planning phase and integrate virtual plans with other software platforms for digitally guided execution. A dento-facial interdisciplinary planning platform virtually simulates interdisciplinary clinical procedures and assists in the decision-making process.

CONCLUSIONS

The suggested classification assists professionals in different phases of the digital workflow and provides guidelines for improvement and development of digital technologies before treatment plan acceptance by the patient.

CLINICAL SIGNIFICANCE

Three-dimensional interdisciplinary simulations allow clinicians to visualize how each dental procedure influences further treatments. With this treatment planning approach, predictability of different procedures in restorative dentistry, orthodontics, implant dentistry, periodontal, and oral maxillofacial surgery is improved.