Maxillary and mandibular implant rehabilitation using a completely digital workflow: A technique.

Complete arch implant scanning is a technique-sensitive procedure involving challenges acquiring the data, using an intraoral scanner, and aligning the obtained scans. A novel technique using a fixed custom scan body with a specific geometry is presented to allow virtual alignment and articulation at the optimal occlusal vertical dimension and centric relation position. The technique is accomplished by relating the geometric position of scan bodies, the interim prosthesis, and the custom scan body with a completely digital workflow.

Evaluation of different tightening protocols on angled screw channel abutments after cyclic loading: An in vitro study.

STATEMENT OF PROBLEM: Screw loosening remains one of the most common complications associated with implant-supported restorations. The available literature is scarce regarding the most efficient method of tightening definitive abutment screws for angled screw channel (ASC) abutments. PURPOSE: The purpose of this in vitro study was to identify the optimal screw tightening protocol for ASC abutments by evaluating the influence of different protocols on reverse tightening values (RTVs). MATERIAL AND METHODS: Fifty implants were randomly assigned to 5 groups (n=10). Implants were mounted and received a cover screw and impression coping to simulate the clinical scenario. Each group was allocated to one of the following protocols: tightened once (1×), tightened twice (2×), tightened twice at a 10-minute interval (2× [10 min]), tightened, countertightened, then tightened again (TCT) and tightened, countertightened, tightened, countertightened, then tightened (TCTCT). A monolithic zirconia central incisor implant crown was fabricated by using computer-aided design and computer-aided manufacturing (CAD-CAM) and cemented onto the ASC abutment. The crown-abutment assemblies were secured onto the implants with the Gold-Tite abutment screw by using their assigned tightening protocols. Each screw was tightened to the recommended value of 20 Ncm with a calibrated digital torque measuring device. Specimens were subjected to 250 000 cycles of cyclic loading simulating 3 months of function with a universal testing machine. RTV was measured for each specimen. RESULTS: The mean RTV for all the groups ranged from 13.5 Ncm to 15.9 Ncm. The highest mean RTV was found with the (1×) protocol. However, the difference was not statistically significant among any of the groups (P>.05). CONCLUSIONS: Multiple retightening and time intervals between tightening events of these ASC abutment screws did not have a significant influence on RTV under simulated function of 3 months. The one time (1×) tightening protocol can be recommended as a suitable method for ASC abutments, thus avoiding unnecessary retightening.

Effect of implant abutment screw materials and tightening protocols on reverse tightening values: An in vitro study.

STATEMENT OF PROBLEM: Implant abutment screw loosening is the most common prosthetic complication of implant-supported single crowns. However, few studies have objectively evaluated the effectiveness of different tightening protocols on reverse tightening values (RTVs). PURPOSE: The purpose of this in vitro study was to determine the optimal tightening protocol for implant abutment screws with different screw materials. MATERIAL AND METHODS: Sixty implants from 2 implant systems (Keystone and Nobel Biocare) with different definitive screw materials were selected. One group used diamond-like carbon (DLC) coated screws (DLC Group), and the other used titanium nitride (TiN) screws (TiN Group). Each group consisted of 30 implants. The implants in each group were distributed randomly into 3 subgroups (n=10). The implants from both manufacturers were mounted in resin blocks by following a clinical component connection protocol: a cover screw was placed, then an impression coping, and finally an original manufacturer prefabricated abutment. The abutment screws were tightened to the manufacturer's recommended tightening value using 3 different protocols: tighten the screw once (1T); tighten the abutment screw to the recommended tightening value, wait 10 minutes, and then retighten (2T); and tighten the abutment screw to the recommended tightening value, countertighten, tighten, countertighten, and then tighten (3TC). RTVs were measured after 3 hours. The Shapiro-Wilk test was performed to test for normal distribution of the data. The Kruskal-Wallis test was applied to each system's group that was not normally distributed (P<.05). Where differences existed, a post hoc analysis using the Dwass-Steel-Critchlow-Flinger (DSCF) pairwise comparisons test was conducted. RESULTS: No significant differences were found among the 3 different tightening groups in the TiN group (P>.05). However, significant differences were found among the 3 different tightening protocols in the DLC group (P<.05). CONCLUSIONS: Abutment screw systems from different manufacturers behave differently with respect to how they are tightened. For the TiN screw group, statistically similar RTVs were found for the 3 tightening protocols. The most efficient tightening protocol for the DLC-coated screw was the 3TC-DLC.

Evaluation of implant abutment screw tightening protocols on reverse tightening values: An in vitro study.

STATEMENT OF PROBLEM: Implant abutment screw loosening is a common prosthetic complication of implant-supported crowns. However, reports that have objectively evaluated the effectiveness of different tightening protocols on reverse tightening values are sparse. PURPOSE: The purpose of this in vitro study was to determine the optimal tightening protocol for implant abutment screws. MATERIAL AND METHODS: Fifty Neoss implants were randomly distributed to 5 groups (n=10). The implants received a cover screw and mounted, and the impression coping was tightened. Tightening was measured by using a digital measuring device. Then, the implant abutments were placed and tightened to 32 Ncm by using a Crystaloc screw. In Group 2T10I, the screws were tightened twice with an interval of 10 minutes between the first and second tightening. In Group 2T0I, the screws were tightened twice with no interval time. In Group 1T, the screws were tightened 1 time only. In Group TCT, the screws were tightened, counter-tightened, and then tightened again. In Group TCTCT, the abutment screws were tightened, counter-tightened, tightened, counter-tightened, and then tightened again. All the mounted implants were left in the same environment for 3 hours, and the reverse tightening values were then measured. RESULTS: The mean reverse tightening values of the first 4 groups ranged from 21.49 Ncm to 22.57 Ncm, whereas the reverse tightening value for the fifth group was 25.51 Ncm. A significant difference was found among the groups (P<.05) with reverse tightening data. CONCLUSIONS: No significant difference was found in tightening the abutment screw 2 times with a 10-minute interval time, no interval time, or tightening it 1 time only. However, a significant difference was found in reverse tightening in the 3-time tightening and counter-tightening group.

Critical factors challenging the integration of AI technologies in healthcare workplaces: a stakeholder assessment.

PURPOSE: This study aims to identify and assess the factors challenging the integration of artificial intelligence (AI) technologies in healthcare workplaces. DESIGN/METHODOLOGY/APPROACH: The study utilized a mixed approach, that starts with a literature review, then developing and testing a questionnaire survey of the factors challenging the integration of AI technologies in healthcare workplaces. In total, 46 factors were identified and classified under 6 groups. These factors were assessed by four different stakeholder categories: facilities managers, medical staff, operational staff and patients/visitors. The evaluations gathered were examined to determine the relative importance index (RII), importance rating (IR) and ranking of each factor. FINDINGS: All 46 factors were assessed as "Very Important" through the overall assessment by the four stakeholder categories. The results indicated that the most important factors, across all groups, are "AI ability to learn from patient data", "insufficient data privacy measures for patients", "availability of technical support and maintenance services", "physicians' acceptance of AI in healthcare", "reliability and uptime of AI systems" and "ability to reduce medical errors". PRACTICAL IMPLICATIONS: Determining the importance ratings of the factors can lead to better resource allocation and the development of strategies to facilitate the adoption and implementation of these technologies, thus promoting the development of innovative solutions to improve healthcare practices. ORIGINALITY/VALUE: This study contributes to the body of knowledge in the domain of technology adoption and implementation in the medical workplace, through improving stakeholders' comprehension of the factors challenging the integration of AI technologies.

Comparison of surface micro-roughness and adaptation of titanium and cobalt chrome implant abutment fabricated by selective laser melting and conventional techniques.

PURPOSE: The objective of this study was to assess the surface micro-roughness and abutment adaptation of selective laser melting (SLM) implant abutments in comparison to cast and machined implant abutments. METHODS: Forty abutment specimens were divided equally into four groups according to the fabrication technique as follows (n = 10), Machined Ti alloy abutments (Control), Cast CoCr abutments, SLM-CoCr abutments, and SLM-Ti alloy abutments. Forty internal connection implants (Ø 4.0 ×10 mm, Superline™, Dentium Co., Seoul, Korea) were mounted in clear acrylic resin. Fabricated abutments were assessed for surface micro-roughness using a 3D optical noncontact surface microscope. Vertical and horizontal adaptation of the abutment with implant interface was assessed by using Bruker micro-CT. Data was assessed using analysis of variance and Tukey post hoc comparison tests for all the variables except vertical misfit was assessed using Kruskal-Wallis test. Pearson correlation was used to assess dependence between independent variable (surface roughness) and dependent variables (Horizontal misfit and vertical misfit). RESULTS: SLM-Ti abutments showed significantly rougher surface (p < 0.05) among the study groups. While SLM-CoCr abutments were smoother than Cast abutments with mean Ra of 1.30 ± 0.11 and 1.58 ± 0.17 µm, respectively (p < 0.05). For abutment adaptation, SLM-Ti abutments showed the highest horizontal misfit among the groups (p < 0.05). While, SLM-CoCr abutments (29.24 ± 11.11 µm) showed comparable (p > 0.05) horizontal misfit results with Cast (26.08 ± 3.93 µm) and machined (26.45 ± 7.33 µm) abutments. Comparable (p > 0.05) vertical misfit values between Cast CoCr (487.01 ± 40.34 µm), SLM-CoCr (358.38 ± 114.93 µm) and SLM-Ti (299.85 ± 172.88 µm) abutments were observed. A positive correlation was found between the surface roughness of the mating surfaces and abutment adaptation. CONCLUSION: SLM CoCr abutments exhibited low roughness and comparable abutment adaptation (vertically and horizontally) than cast (control) abutments. Therefore, SLM CoCr abutments should be clinically investigated as potential implant abutments for clinical use.