International Journal of Computerized Dentistry最新文献

Aim: New technologies such as tactile robots and artificial intelligence (AI) are finding their way into clinical practice in dentistry and could contribute to the improvement of oral health care in the future. The hypothesis of the present in vitro pilot study trial was that a collaborative tactile robot programmed by a dental student could remove interproximal artificial plaque as effectively as a human operator.

Materials and methods: Model teeth were fully covered with artificial plaque and set into phantom jaws. First, a robot was programmed by a dental student to perform interproximal cleaning with an interproximal brush. Second, the teeth were covered with artificial plaque again, and the dental student performed the interproximal cleaning manually. Both experiments were repeated five times. Residual plaque was measured with binary pictures. Surface coverage was reported, and the comparison of methods was performed with significance defined at α = 0.05.

Results: No statistically significant difference was found in the cleaning result between the robot and the human operator.

Conclusion: The results of the present in vitro pilot study indicate that a tactile robot with integrated AI programmed by a dental student can perform interproximal cleaning as effectively as a dental student.

Practical implications: In the future, the use of robot assistants to support oral hygiene, eg, in patients with reduced motor skills or impaired vision, should be fur ther investigated.

Aim: The aim of the present in vitro study was to investigate the effects of different sintering procedures on the fit, color parameters, and fracture load of monolithic fixed partial prostheses (FPPs).

Materials and methods: A metal master model was scanned and FPPs were designed. Groups were created by fabricating FPPs using four different sintering procedures (n = 10): Prettau-Standard (PST); Prettau-Slow (PSL); Ice-Speed (ISP); Ice-Standard (IST). PST-PSL (Group P; N = 20) and ISP-IST (Group I; N = 20) were colored with different coloring liquids. The marginal and internal fit were measured using the silicone replica method. CIELAB values of the samples were measured using a spectrophotometer. Then, for each sample, the die was obtained from polymethyl methacrylate. The specimens were cemented into dies and tested in a universal testing machine for fracture load. One-way ANOVA was performed to assess the effect of the sintering procedure on the marginal and internal fit; fracture load; and ∆E00, ∆L', ∆C', and ∆H' values of the FPPs.

Results: The PSL and PST groups showed significantly smaller internal and marginal fit values compared with the ISP group. Additionally, the internal fit values of the IST group were significantly higher than those of Group P. Sintering time reduction led to a decrease in ∆E00 values. Fracture load values were not statistically significantly affected by the different sintering procedures for both brands.

Conclusion: Different sintering procedures did not have a clinically significant effect on fit and fracture load. Different sintering procedures were found to have an impact on the color change of monolithic zirconia restorations.

Aim: The aim of the present study was to evaluate the segmentation accuracy of the dentition by testing four open-source semi-automatic software programs.

Materials and methods: Twenty CBCT scans were selected to perform semi-automatic segmentation of the maxillary and mandibular dentition. The software programs tested were InVesalius, ITK-SNAP, 3D Slicer, and Seg3D. In addition, each tooth model was manually segmented using Mimics software; this was set as the gold standard (GS) reference of the investigation. A specific 3D imaging technology was used to perform the superimposition between the tooth models obtained with the semi-automatic software and the GS model as well as to perform the surface-to-surface matching analysis. The accuracy of semi-automatic segmentation was evaluated, calculating the volumetric mean differences (mean bias and limits of agreement) and the percentage of matching of the tooth models compared with the manual segmentation (GS). Qualitative assessments were performed using color-coded maps. All data were statistically analyzed to perform comparisons between the investigated software programs.

Results: Statistically significant differences were found in the volumetric and matching percentage data (P 0.05). InVesalius was the most accurate software program for 3D rendering of the dentition, with a volumetric bias (Mimics software) ranging from 4.59 to 85.79 mm3, while ITK-SNAP showed the highest volumetric bias, ranging from 30.22 to 319.83 mm3. The mismatched area was mainly located at the radicular tooth region. The volumetric data showed excellent inter-software reliability, with coefficient values ranging from 0.951 to 0.997.

Conclusion: Different semi-automatic software algorithms could generate different patterns of inaccuracy error in the segmentation of teeth.

Aim: To report on a novel digital superimposition workflow that enables measuring the supra-crestal peri-implant soft tissue dimensions all along implant treatment and afterwards.

Materials and methods: A preoperative CBCT and intra-oral scans (IOS) are successively taken before surgery, at the end of the healing period, at prosthesis delivery, and over time; they are digitally superposed on a dedicated software. Then, the stereolithography files (STL) of the healing abutment, of the prosthetic abutment and the crown are successively merged into the superposition set of IOSs.

Result: The workflow protocol of merging successively the STL of each item into the superposition set of IOSs enables capturing the dimensions of the height and width of the supra-crestal soft tissues, at every level of the healing abutment, the prosthetic abutment and the crown. In addition, it allows measuring the vertical distance that the crown exerts pressure on the gingiva and the thickness of the papillae at every level of the abutment.

Conclusion: This novel digital superimposition workflow provides a straightforward method of measuring the vertical and horizontal dimensions of the supra-crestal peri-implant soft tissues, including the papillae, at each stage of the implant treatment process. It allows investigating a certain number of soft tissue variables that were previously inaccessible to clinical research. It should help enhancing our comprehension of the peri-implant soft tissue dynamics.

Purpose: Is to investigate how integrating intraoral scanners in routine oral diagnosis affects patient-clinician communication, patient perceptions and preferences, offering valuable insights into the patient experience and utility of intraoral scanners in clinical practice.

Materials and methods: A restorative dentistry specialist conducted intraoral examination on 300 patients, initially using conventional techniques and X-rays, followed by a 3D scanner (ITero®element, Align Technologies, San Jose, California, USA). The patient's existing oral issues and treatment plan were initially expressed verbally, and then repeated using a 3D scan. Subsequently, the patients were requested to respond to an 11-question survey, aimed at assessing both modes of examination and communication. Statistical analysis using SPSS v.22 software included employing the Wilcoxon test to compare the patients' experiences on the same topic before and after the examination with the intraoral scanners, considering significance at p<0.05.

Results: Majority (38%) of participants aged 25-35. Gender split was 52% female, 48% male. Patients statistically found it more comprehensible to visualize existing oral issues through 3D scans than through verbal explanation (p=0.000). Also, patients understood oral hygiene recommendations better when explained via 3D scanning by dentists (p=,000). The vast majority of the participants (94%) indicated that being examined with an intraoral scanner motivated them for treatment, while 6% remained undecided. A hundred percent of the participants stated that 3D scanners should be included in the routine oral examination.

Conclusion: Intraoral 3D scans enhance patient understanding and communication during oral examination and participants show high preference. However, more research needed to replace conventional diagnostic methods.

Objective: To investigate the application of dynamic navigation guidance technology in different implantation scenarios, and to provide a scientific basis for the innovation and advancement of implantation techniques.

Methods: Fifteen cases of patients with malocclusions admitted between January 2021 and February 2023 were selected as the study subjects. All patients underwent dynamic navigation-guided oral implantation interventions. CBCT scans were taken after implantation surgery to record deviations of implantation points, including implantation point deviation, endpoint deviation, and angle deviation.

Results: Dynamic navigation guidance effectively improves the reliability and stability of implantation in oral implant patients. CBCT effectively evaluated the state of the patient's periodontal implant, analyzed the state of the patient's lesion area, and improved the quality of implant intervention through CBCT guidance. The implantation point deviation was (0.407±0.193) mm, the endpoint deviation was (0.492±0.201) mm, and the implant angle deviation was (2.162±0.283)°. There was no significant difference in implantation point deviation in the anterior and posterior parts of the upper and lower jaws after intervention (P>0.05). However, there were significant differences in endpoint deviation and implant angle deviation among the anterior and posterior parts of the upper and lower jaws (P<0.05).

Conclusion: Dynamic navigation guidance effectively improves the reliability and stability of implantation in oral implant patients. However, there is relatively greater endpoint deviation and implant angle deviation in the posterior part of the upper jaw.

Aim: The current study aimed to compare the responses and satisfaction reported by users with varying levels of experience when using different types of computer-aided design (CAD) software programs to design crowns.

Materials and methods: A questionnaire was used to evaluate user responses to five domains (software visibility, 3Dscanned data preparation, crown design and adjustment, finish line registration, and overall experience) of various CAD software programs. The study included 50 undergraduate dental students (inexperienced group) and 50 dentists or dental technicians from two hospitals (experienced group). The participants used four different CAD software programs (Meshmixer, Exocad, BlueSkyPlan, and Dentbird) to design crowns and recorded the features using the questionnaire. Statistical analyses included one-way and two-way analysis of variance (ANOVA) tests to compare scores and verify the interaction between user response and experience.

Result: User evaluation scores in the domains of software visibility and 3D-scanned data preparation varied between software programs (P < 0.001), with Exocad being favored by the experienced group. When evaluating crown design and finish line registration, Dentbird and Exocad scored significantly higher than the other software in both groups as they offered automation of the process using deep learning (P < 0.001). Two-way ANOVA showed that prior experience of using CAD significantly affected the users' responses to all queries (P < 0.001).

Conclusion: User response and satisfaction varied with the type of CAD software used to design dental prostheses, with prior experience of using CAD playing a significant role. Automation of design functions can enhance user satisfaction with the software.

Aim: Condylar hyperplasia (CH) is a progressive and deforming disease that modifies anatomy of the temporomandibular joint (TMJ) structures. This study aims to correlate the metabolic bone activity of the condyle measured by SPECT with the volumetry anatomic information from the condyle, fossa and joint space provided by CT images, in patients with CH in active and inactive forms.

Materials and methods: A cross-sectional comparative study was performed with a set of 116 images from healthy and diagnosed CH patients to compare volumetric measures of the TMJ. Images were acquired through a bone tissue mask using a three-dimensional DICOM reconstruction for SPECT/CT and CBCT images and the Threshold option for segmentation with standardized values for each tissue on the HU scale.

Results: there are differences (p<0.01), with greater condylar volume on the affected side in patients with active CH compared to passive CH. The volume of the glenoid cavity shows no differences in either form of CH (p>0.05), however, there were differences for the volume of the joint space on the affected right side of hemimandibular elongation (HE) in the active form. The volume of the mandibular condyle on the affected side in CH cases were larger in HE cases in active and inactive form (p<0.01) compared to healthy patients. Similar results were presented for the glenoid cavity and joint space.

Conclusions: Volumetric anatomical evaluation of TMJ structures, as well as information on condylar metabolic activity, can be obtained from SPECT/CT. The study shows a greater condylar volume on the affected side of the CH compared to the contralateral side, but there are more significant differences in the active than in the inactive form.