International Journal of Computerized Dentistry最新文献

Aim: To assess the agreement rates of dental records derived from intraoral scan-based digital 3D models (3DM) and 3DM plus panoramic radiographs (3DM+PAN-X) compared with clinical findings.

Materials and methods: Based on the 3DM/3DM+PAN-X of 50 patients undergoing supportive periodontal therapy (SPT), 10 remote raters (inexperienced in using intraoral scanners [IOSs] or 3DM) assessed for each site of the dental scheme (32 sites) whether a tooth was missing (M), filled (F), restoration- and caries-free (H), replaced by an implant (I), or decayed (D). Remote records were compared with the clinical reference record of each patient at tooth level. The clinical records were assessed by an experienced dentist who supplemented the clinical findings with information from available radiographs and the patient records to define the clinical reference record.

Results: The agreement rates for 3DM/3DM+PAN-X at tooth level were: M: 93%/94%, F: 84%/88%, H: 92%/92%, I: 65%/96%, D: 29%/29%. The overall agreement rate (odds ratio [OR]) was 88% for the 3DM-based dental records (14,093 of 16,000 entries true), and 91% for 3DM+PAN-X (14,499 of 16,000 entries true). Using 3DM for dental record assessment, posterior teeth had higher odds of correct findings compared with anterior teeth (maxillary jaw OR = 2.34, mandibular jaw OR = 1.27).

Conclusions: The remote detection of healthy, missing, and filled teeth as well as implants by raters inexperienced in using IOSs or 3DM showed a high agreement rate with the clinical findings. The additional evaluation of PAN-X increased the agreement rate significantly for implants. Thus, the remote assessment of dental records using 3DM+PAN-X had a high accuracy when applied in SPT patients with low caries activity.

Medical imaging technology has greatly improved over the last 40 years. A good example of this is the improved 3D reconstruction capabilities of computed tomography (CT), which enable photorealistic reconstructions. This technological advancement has also taken place in the computer industry, and the development of modern graphics cards has fueled progress in video games. In art, many of the techniques used to improve three-dimensionality have been known for centuries. At first sight, these fields seem unrelated, but there is actually considerable confluence. The present article focuses on three areas: fine arts, video games, and medical imaging. The art section illustrates different drawing techniques used to create three-dimensionality. The video games section shows the development of video games from the 1980s to the present day. Finally, the medical imaging section focuses on the first 3D radiography reconstructions in the 1980s and the improvements to the present day. Contemporary video games and 3D reconstructions of CT scans enable photorealistic impressions of 3D anatomical structures. An important factor is shadow casting and light, which has been known in fine arts for centuries. The effect on the observer of photorealistic 3D reconstructions in video games and in medical imaging can largely be explained by the knowledge of 3D techniques used in drawings and paintings.

Aim: Mandibular single-implant overdenture is a well-established treatment modality for the management of completely edentulous patients. The use of CAD/CAM printing technology to fabricate complete dentures and overdentures is burgeoning. The present randomized controlled clinical trial (RCT) aimed to clinically evaluate 3D-printed single-implant overdentures and compare their outcomes with those of overdentures fabricated using conventional techniques.

Materials and methods: An RCT was designed. Twenty-eight participants were randomly allocated into two equal groups. Participants in the control group received conventionally fabricated single-implant overdentures, while those in the intervention group received digital light processing-printed single-implant overdentures. An evaluation was conducted to assess implant survival and success rates as well as overdenture survival and success, along with the measurement of maximum bite force (MBF) over a 1-year follow-up period. Data were collected and subjected to statistical analysis. Statistical significance was determined using a two-sided P value with a threshold of less than 0.05.

Results: The 3D-printed group had higher implant survival (100%) and success (92.8%) rates compared with the conventional group (85.7% survival, 85.7% success). Overdenture survival and success rates were 100% in the 3D-printed group and 78.6% in the conventional group. Both groups showed a significant increase in MBF at the 3-, 6-, and 12-month follow-ups (P 0.001). The 3D-printed group demonstrated a statistically significant improvement in MBF compared with the conventional group (P 0.001).

Conclusions: 3D-printed mandibular single-implant overdentures may represent an alternative to conventionally fabricated ones.

Aim: Although many fields of dentistry allow digital processes today, analog procedures are still widely used. The present cross-sectional pilot study aimed to provide insights into the digitalization of dental practices using the example of Hesse.

Materials and methods: Between April and June 2022, 4840 active practicing dentists registered by the State Dental Association of Hesse were invited via email to fill out an online questionnaire regarding their technical requirements in dental practice, dental treatment procedures, and attitude toward digitalization in dentistry. Demographic questions were asked. Besides descriptive statistics, correlations were analyzed (P 0.05).

Results: Questionnaires of 937 dentists (279 females, 410 males, 4 inter/diverse, 244 no answers; mean age of 51.4 ± 10.4 years) were examined, representing a response rate of 19.36%. In the area of practice administration and dental radiography, the majority of the dentists surveyed were already working digitally, which is predominantly assessed as a positive development. One third of the respondents stated that they already used an intraoral scanner for dental treatments, but for indications mainly limited to minor restorations. However, many dentists rated the use of social media accounts and telemedicine rather negatively.

Conclusion: Within the limitations of this cross-sectional pilot study, it was shown that many dental treatments were still being performed by analog processes. However, 60% of the participants planned the digitalization of their dental practices within the next 5 years, which indicated a clear shift from analog to digital dentistry.

Aim: Fracture of abutment teeth with telescopic crown-retained removable partial dentures (TCDs) is a common cause of failure for this prosthetic restoration. In many cases, a telescopic crown (TC) can only be refitted after post and core (PC) treatment due to an insufficient retention surface. Furthermore, if the root canal has an elliptic cross-sectional area or the coronal defect is severe, customized cast post and cores (CPCs) are still the therapy of choice. Nevertheless, the disadvantage of CPCs is longer chair time due to the need for a second appointment for insertion. In addition, the mechanical properties of the alloy do not match with dentin, leading to a higher risk of root fracture. In such cases, CAD/CAM PCs fabricated in a fully digital chairside workflow can accelerate the treatment and decrease the risk of root fractures by using materials with matching mechanical properties.

Materials and methods: The case series presented in this article includes 12 patients who were treated with TCDs and experienced abutment tooth fracture that required PC treatment to refit TCs. The post space preparation as well as the TCDs were scanned in less than 10 min for the fabrication of CAD/CAM PCs out of a fiber-reinforced CAD/CAM composite.

Conclusions: With the presented fully digital chairside workflow, PC fabrication can be accelerated because a second appointment is not needed for customized PCs. The presented workflow might be an alternative to that for conventional PCs to refit TCs after abutment tooth fracture. The CAD/CAM-fabricated PC offers mechanical properties close to dentin and can be fabricated chairside in a short period of time.

Purpose: The purpose of the study was to investigate the accuracy of complete-arch intraoral scans for all-on-4 implant treatment under simulated intraoral variables.

Materials and methods: A maxillary model designed to receive 4 implants in the regions of first molars and canines was used. Intraoral digital scans were completed in a simulation device by simulating two2 different clinical conditions: normal intraoral variables (NIV) and limited intraoral variables (LIV). Digital scans were obtained using five 5 different IOSs: Trios 3 (TRI), Primescan (PR), iTero 2 (ITE), Medit i500 (MDT), and Aadva IOS 100P (AAD). Ten scans of each IOS were made and exported as STL files. Assessment of precision and trueness was conducted with Geomagic 3D analysis software. Each STL file was individually aligned with the reference scan and 3D differences were calculated using the root mean square (RMS) value. Data was statistically analyzed using 2-way ANOVA and Tukey HSD tests (α=.05).

Results: Regarding trueness, 2-way ANOVA and Tukey comparison tests revealed significant differences between different IOSs and intraoral variables. The AAD under LIV presented significantly higher RMS than TRI, PR, ITE, and MDT (p<.001). Regarding precision, the lowest mean RMS was obtained in the IOS group of PR under NIV. AAD presented significantly higher mean RMS in the groups of both NIV and LIV (p<.001). Limited intraoral variables significantly increased the RMS values for all IOSs tested (TRI, PR, ITE, MDT, and AAD).

Clinical significance: Accuracy of complete arch all-on-4 implant scans were affected by different IOSs and intraoral variables. Simulating intraoral variables while testing IOSs might help to better validate their clinical use.

Purpose: This in vitro study investigates the accuracy of digital impressions taken with different dental materials. It compares the scan accuracy and trueness of a handheld scanner operated by an experienced clinician, a handheld scanner operated by a robotic arm, and a tabletop scanner. By measuring the number of triangles, average degree, and vertices within the three groups, conclusions about the accuracy of different scanning methods on digital models can be drawn.

Materials and methods: Standard-sized models made from various dental materials were used. The scanners tested included a tabletop scanner, a handheld scanner operated by an experienced clinician, and a handheld scanner operated by a robotic arm. The number of triangles, average degree, and number of vertices were recorded and compared. Statistical analysis was performed to identify significant differences between the groups.

Results: The tabletop scanner produced the fewest triangles in the digital model, while the handheld scanner operated by the experienced clinician had the most. Significant differences were found in the number of triangles, average degree, and vertices among different dental restorations. The handheld scanner used by the experienced clinician produced the most accurate and true digital model, followed by the robotic arm-operated handheld scanner, and then the tabletop scanner. The use of different dental materials significantly affected the accuracy of digital impressions.

Conclusion: This study highlights the accuracy and trueness of digital impressions using various dental materials and scanners. The findings suggest that the operator's experience and scanner type impact digital impression accuracy. These insights have implications for clinical practice, indicating the need for further studies to confirm these results and explore other influencing factors in dental digital impressions.

Aim: The present randomized controlled clinical trial focused on graft volume alterations after sinus floor augmentation with a deproteinized bovine bone mineral (DBBM; Bio-Oss), a deproteinized porcine bone mineral (DPBM; THE Graft), or a biphasic calcium phosphate (BCP; Osopia) material.

Materials and methods: A total of 28 patients with edentulism in the posterior maxilla with ≤ 5 mm of residual bone height received a two-staged external sinus grafting procedure with DBBM, DPBM, or BCP. Three CBCT scans were performed: 1) prior to surgery (CBCT1); 2) directly after surgery (CBCT2); 3) after a healing period of 4 to 6 months, prior to implant placement (CBCT3). The CBCT scans were used to analyze volumetric alterations of the sinus grafts by virtual 3D model matching of CBCT1 and CBCT2 (situation after sinus grafting), and CBCT1 and CBCT3 (situation prior to implant placement).

Results: The volume of the bone graft in the maxillary sinus (volume [VOL%] directly after grafting rated as 100%) was stable after the healing period in the DBBM (VOL%: 103 ± 4%) and the DPBM (VOL%: 112 ± 23%) groups, with no statistically significant differences regarding 3D measurements. In the BCP group, the grafted volume declined to VOL%: 66 ± 25%, statistically inferior to the DBBM and DPBM groups.

Conclusions: Regarding bone graft stability/volume, the DBBM and DPBM groups showed comparable outcomes. Due to resorption, the BCP group showed inferior bone graft volume after healing (statistically significant) compared with the DBBM and DPBM groups.

Aim: Virtual reality (VR) technologies can be used as a content-delivery system for the purposes of both entertainment and education. Remote and digital education has become increasingly important in a world where disruptive events such as global pandemics and natural disasters can define access to face-to-face learning environments. An important aspect of VR technologies for dentistry is the creation of digital 3D models. The primary objective of the present review was to answer the focused research question: 'What software techniques are used in the creation of digital 3D models for use in dental education?'

Methods: The study systematically evaluated current software and techniques used for creating digital 3D models in dental education using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses).

Results: The search strategies did not find any specific studies relating to the creation of dental-related 3D models. Therefore, this is the first study to provide an overview of common techniques of 3D model fabrication. In addition, some examples of methods of creating 3D models relevant to dentistry such as armamentarium and anatomical oral structures are discussed in considerable detail.

Conclusion: The creation of 3D modeling is a rapidly evolving field, with software updates and new programs being continually released. The present study highlights the fundamental lack of published work in the creation of 3D dental models for educational applications.