International Journal of Computerized Dentistry最新文献

Aim: The adjustment and transfer of a stable occlusion can be a major challenge in prosthetic rehabilitations. The aim of the present study was to assess a noninvasive treatment option for complex prosthetic rehabilitations and occlusal analyses using 3D-printed restorations clinically.

Materials and methods: Eleven patients received a partial or complete rehabilitation with the aid of 3D-printed restorations (n = 171). After 12 months of clinical service, all restorations were analyzed using the United States Public Health Service (USPHS) criteria.

Results: The 12-month clinical data revealed that 3D-printed restorations showed a survival rate of 84.4%. Complications occurred mostly regarding the anatomical form (7%) or marginal integrity (6%) and were consequently rated 'Charlie' or 'Delta.' Color stability and color match of 3D-printed restorations were rated 'Alpha' in 83% and 73%, respectively, of all restorations. Marginal inflammation was rated 'Alpha' in 89% of all restorations. An excellent surface texture and no secondary caries or postoperative sensitivities (100%) were observed.

Conclusions: 3D-printed restorations might be an alternative treatment option for initiating complex prosthetic rehabilitations. Technical complications rarely occurred. Biologic complications did not occur at all. The color stability showed promising results after 12 months of clinical service. However, the results should be interpreted with caution until long-term results with a high number of restorations are available.

Aim: The purpose of the present systematic review and meta-analysis was to evaluate the marginal adaptation of single-unit full-coverage lithium disilicate fixed dental restorations fabricated with the conventional heat-pressed technique and the digital CAD/CAM workflow.

Materials and methods: The present study was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. Α study research was conducted in Medline via PubMed and Cochrane Library databases together with a hand search of studies published until June 2022. The search terms combined suitable MeSH (Medical Subject Headings) terms together with free text words in single or multiple conjunctions. A modified methodological index was used to assess the risk of bias of the included studies. A random effects model was applied to pool the effect estimates, and further assessment of the heterogeneity across studies was conducted using the Q test and the I2 metric. All statistical analyses were performed with RStudio software, version 4.1.2, using the 'meta' package.

Results: The electronic search and hand search identified 51 articles. Eighteen articles met the inclusion criteria and were included in the systematic review, 17 of which were in vitro studies and only 1 was an in vivo study. However, only 17 of the initial 18 articles could be included in the meta-analysis due to a lack of statistical data in one of the in vitro studies. Statistical analyses were conducted using the RStudio software program. Meta-analysis was performed with the random effects model (α = 0.05). No statistical difference was found between the two fabrication methods (P = 0.49).

Conclusions: Although the mean marginal adaptation of lithium disilicate single crowns was found to be better with the heat-pressed technique, there was no statistical significance with the CAD/CAM-fabricated restorations, and both resulted in a clinically acceptable result. Nonetheless, more clinical studies are needed for safer conclusions.

Aim: The objective of the present study was to evaluate the failure rate of palatal computer-guided miniscrews placed in the paramedian (PM) and parapalatal (PP) regions for orthodontic purposes. An additional aim was to investigate whether a learning curve was required to perform computer-guided miniscrew insertion as well as to evaluate the peri-implant soft tissue response at three follow-up time points.

Materials and methods: A total of 202 palatal computer-guided miniscrews were inserted in 78 subjects for orthodontic purposes. A surgical guide was designed after planning the appropriate insertion sites on 3D images created by the fusion of CBCT scans and digital dental model images. The orthodontic appliances were disassembled monthly to perform a percussion test and evaluate the mobility of each miniscrew. To determine whether a learning curve was required for computer-guided miniscrew insertion, the time point of miniscrew failures and the number of surgeries were evaluated. Bleeding on probing (BOP) and probing pocket depth (PPD) were recorded for each miniscrew at 2- (T0), 6- (T1), and 12-month (T2) follow-up time points.

Results: An immediate failure rate of 4.95% was recorded due to lack of primary stability immediately following miniscrew insertion, with a statistically significantly higher failure rate of PP miniscrews (P = 0.00). Failure of the miniscrews occurred at random times, with no learning curve required for their insertion. The measured BOP rates (mean: 3.13%) and PPD values (mean: 1.68 mm) remained stable over time.

Conclusions: Computer-guided miniscrew insertion in the palatal vault showed a low failure rate without a determined learning curve required for their insertion to obtain predictable results and with long-term stability of peri-implant soft tissue indices.

Aim: Learning tooth preparation techniques and the finesse required is an important part of preclinical dental education. Being able to practice surgical skills without loss of Frasaco teeth while being provided with performance analysis data is a boon to students and educators. The present authors investigated the combination of haptics-enhanced virtual reality (Simodont) and conventional phantom head practice in a preclinical dental course, evaluating the students' performances and perceptions.

Materials and methods: Forty students were randomized into two groups: Group One worked within a VR-haptic setting, while Group Two worked with Frasaco teeth. Halfway through the course, the scenarios were switched. A crown preparation test on the Frasaco teeth was conducted at the end of the course. Students' performances and satisfaction were assessed anonymously. Analysis of the students' performances included clinical metrics (occlusal and axial reduction, convergence angle, damage to adjacent teeth). The perceived usefulness of VR-haptic and phantom head simulations was assessed.

Results: In Group One, the tooth preparation metrics were more in line with the requested parameters compared with Group Two. All students ranked VR-haptics highly with regard to manual dexterity improvement.

Conclusion: The present study shows that by combining VR-haptics with conventional dental procedures it is possible to improve important preparation metrics in fixed prosthodontics tooth preparation.

Aim: The objective of the present study was to investigate the clinical understanding and reasoning abilities of large language models (LLMs); namely, ChatGPT, GPT-4, and New Bing, by evaluating their performance in the NDLE (National Dental Licensing Examination) in China.

Materials and methods: Questions from the NDLE from 2020 to 2022 were selected based on subject weightings. Standardized prompts were utilized to regulate the output of LLMs for acquiring more precise answers. The performance of each model across each subject category and for the subjects overall was analyzed employing the McNemar's test.

Results: The percentage scores obtained by ChatGPT, GPT-4, and New Bing were 42.6% (138/324), 63.0% (204/324), and 72.5% (235/324), respectively. Significant variance was seen between the performance of New Bing compared with ChatGPT and GPT-4. GPT-4 and New Bing outperformed ChatGPT across all subjects, with New Bing surpassing GPT-4 in most subjects.

Conclusion: GPT-4 and New Bing exhibited promising capabilities in the NDLE. However, their performance in specific subjects such as prosthodontics and oral and maxillofacial surgery requires improvement. This performance gap can be attributed to limited dental training data and the inherent complexity of these subjects.

Objective: The purpose of this study was to assess the accuracy of full coverage crowns produced by two manufacturing methods: additive 3D printing and subtractive milling utilizing three different predefined cement spaces.

Materials and methods: Six groups were allocated based on the manufacturing method and the predefined cement space: printed wax with a 20 µm space (PW1); printed wax with a 50 µm space (PW2); printed wax with a 100 µm space (PW3); milled wax with a 20 µm cement space (MW1); milled wax with a 50 µm cement space (MW2); milled wax with a 100 µm cement space (MW3); milled zirconia coping with a 20 µm cement space (MZ1); milled zirconia coping with a 50 µm cement space (MZ2); milled zirconia with a 100 µm cement space (MZ3). All fabricated specimens were scanned using an Identica Blue 3D scanner and saved as standard tessellation language (STL) files. A triple scan method was performed using 3-matic software to assess accuracy. The discrepancy values were recorded in micrometers, and the analysis was conducted using one-way ANOVA.

Results: The wax printing method, with a cement gap design of 100 μm, demonstrated a significant improvement in the accuracy compared to the other methods (P<.01). In contrast, the zirconia milling method exhibited significantly lower accuracy relative to the other techniques (P<0.01). Moreover, different cement spaces resulted in various accuracy levels but the only statistically significant difference was observed for the 100 µm cement space in the printed wax group.

Conclusion: The additive 3D printing method exhibited greater accuracy than the subtractive milling approach. Furthermore, altering the cement gap was found to impact the accuracy of both techniques, albeit without statistical significance.

Clinical significance: The accuracy of each CAM technique was investigated in this study, highlighting the promising accuracy of 3D-printed patterns for the lost-wax technique over direct crown milling. However, all methods produced reliable and accurate crown restorations.

Aim: Artificial intelligence (AI)-based systems are used in dentistry to ensure a more accurate and efficient diagnostic process. The objective of the present study was to evaluate the performance of a deep learning (DL) program for the detection and classification of dental structures and treatments on panoramic radiographs of pediatric patients.

Materials and methods: In total, 4821 anonymized digital panoramic radiographs of children between 5 and 13 years of age were analyzed by YOLOv4, a CNN (Convolutional Neural Networks)-based object detection model. The ability to make a correct diagnosis was tested on samples from pediatric patients examined within the scope of the study. All statistical analyses were performed using SPSS version 26.0 software.

Results: The YOLOv4 model diagnosed the primary teeth, permanent tooth germs, and brackets successfully, with high F1 scores of 0.95, 0.90, and 0.76, respectively. Although this model achieved promising results, there were certain limitations for some dental structures and treatments, including fillings, root canal treatments, and supernumerary teeth. The architecture of the present study achieved reliable results, with some specific limitations for detecting dental structures and treatments.

Conclusion: The detection of certain dental structures and previous dental treatments on pediatric panoramic radiographs by using a DL-based approach may provide early diagnosis of some dental anomalies and help dental practitioners to find more accurate treatment options by saving time and effort.

Aim: The objective of the present study was to determine the 3-year clinical and dimensional soft tissue change following implant placement in healed sites before and after loading with either customized or conventional healing abutments.

Materials and methods: Premolar/molar implants were immediately loaded with either provisional and customized abutments without finishing lines according to the principles of the biologically oriented preparation technique (BOPT; test group) or conventional healing abutments (control group). Three months later, the definitive crowns were fabricated. Primary outcomes (soft tissue changes) and secondary outcomes (adverse events) were registered.

Results: A total of 50 of the 87 subjects who were originally included were finally selected for the present retrospective analysis: 23 in the test group and 27 in the control group. During the first days after surgery, two adverse events of mucositis occurred, one in each group. A few technical complications were recorded such as the unscrewing of four screw-retained crowns. A significant increase in the alveolar width was observed in both groups (test: +2.5 ± 0.5 mm; control: +1.0 ± 0.9 mm). The widths appeared unchanged from 3 months to 3 years in both groups. There were no significant differences regarding the width of the keratinized mucosa measured at baseline and after follow-up. The Jemt papilla index showed a higher increase in the test group compared with the control group.

Conclusions: Within the 3-year follow-up period, the peri-implant soft tissue outcomes of single, immediately loaded implants with customized healing abutments showed better results in terms of thickness and width compared with those of the conventional group. The number of side effects (mucositis and dehiscence) appeared to be very similar for both groups. In addition, customized healing abutments led to significant augmentation of the alveolar width, which was more than twice of that registered in the conventional group.

Aim: The objective of the present study was to investigate the effect of using different materials for the fabrication of implant abutments and crowns on the mechanical behavior of implant-supported single crowns after artificial aging. The materials were tested in different combinations to reveal whether using stiff or resilient materials as an abutment or a crown material might influence the fracture strength of the whole structure.

Materials and methods: A total of 40 implants (blueSKY) were restored with identical custom-made CAD/CAM abutments milled out of lithium disilicate or ceramic-reinforced polyetheretherketone (PEEK) and divided into five test groups (n = 8). Forty crowns made of three different materials (zirconia, lithium disilicate, and ceramic-reinforced PEEK) were used to restore the abutments. Specimens were subjected to mechanical loading up to 1,200,000 cycles in a chewing simulator (Kausimulator) with additional thermal cycling. The surviving specimens were subjected to quasi-static loading using a universal testing machine (Z010).

Results: The PEEK abutments with zirconia crowns showed the highest median failure load (3890.5 N) while the PEEK abutments with lithium disilicate crowns exhibited the lowest (1920 N). Fracture and deformation occurred in both the crowns and abutments.

Conclusion: The failure load of the restorations was influenced by the material of the abutment and crown. Restoring PEEK abutments with zirconia crowns showed a high failure load and no screw loosening.

Aim: The objective of the present article is to demonstrate the digital workflow used to manufacture an adjusted oral splint in a patient case.

Materials and methods: A 25-year-old female patient presented for management of her bruxism. Therefore, an adjusted oral splint was manufactured. A computer-aided motion analysis of the patient was conducted (JMA Optic). Full-arch scans of the maxilla and mandible, a biocopy of the maxilla with a bite fork, and buccal scans of the centric jaw relation (Primescan) were performed. The jaw relation was determined beforehand by ballistic closing on a chairside-fabricated anterior jig. The digital construction of a Michigan splint took place in the dental laboratory. The design was nested and milled from a polymethyl methacrylate (PMMA)-containing blank (CLEARsplint Disc).

Results: The oral splint was inserted into the patient's mouth and checked to ensure a tension-free fit. The static and dynamic contact relationship was checked. During the follow-up visit, the patient reported an improvement in tension in the masticatory muscles.

Conclusion: The described procedure allows for the manufacture of an adjusted oral splint through a purely digital workflow.