Prosthetic screw loosening is a common mechanical complication of implant-supported fixed dental prostheses. Although techniques for detecting screw loosening in single implant-supported fixed dental prostheses have been reported, studies on the screw stability for splinted implant-supported fixed dental prostheses are lacking. The purpose of this in vitro study was to determine whether acoustic resonance frequency analysis using a newly developed system could detect prosthetic screw loosening in splinted implant-supported fixed dental prostheses. Maxillary and mandibular edentulous gypsum casts with screw-retained definitive fixed dental prostheses supported by 6 implants were used. A tapping simulation (0.2N, 50Hz) was directly applied to the buccal side of the tested screw, and a pickup device was used to collect the acoustic signals. The resonance peak frequencies of these signals were extracted by using time-frequency-domain analysis based on short-time Fourier transform. A 2-way mixed analysis of variance was performed to evaluate how jaw position and insertion torque affect resonance peak frequency. The Pearson correlation analysis was used to assess the relationship between the insertion torque and resonance peak frequency for each screw (α=.05). Deviation from the insertion torque resulted in significant changes in the resonance peak frequency within 6 to 9kHz. Additionally, significant positive correlation between the insertion torques and resonance peak frequencies was observed for all screws (P<.05). This correlation was affected by the position of the screw within the prosthesis. Specifically, screw loosening in the posterior and anterior regions had a greater influence on the resonance peak frequency than that in the central region. The acoustic resonance peak frequency shifted leftward as the screw preload torque decreased, indicating a significant correlation with screw stability. These results suggest that acoustic resonance frequency analysis can be used to detect the stability status of a single prosthetic screw in a splinted implant-supported fixed dental prosthesis conveniently and with high sensitivity.

The rehabilitation of patient function and esthetics is essential from a social and psychological point of view. After a maxillary resection, the supporting structures that help provide retention or stability to a removable prosthesis are lacking. An effective, functional, straightforward, comfortable, and esthetic prosthetic rehabilitation of a patient with a resected maxilla using a digital workflow is presented. The rehabilitation was done using a computer-aided design and computer-aided manufactured bar and clip-supported overdenture prosthesis over quad zygomatic implants.

Abutment screw loosening is the most common complication in single implant-supported crowns, typically remedied by simply reattaching the restoration, preferably using a new abutment screw. The internal aspect of the implant along with any other components should be decontaminated before reconnection. This clinical report provides information on the appropriate management of the decontamination process, as well as evidence of the foreign material found within the implant body.

Implant-supportedmonolithic zirconia restorations manufactured using the additive 3-dimensional (3D) gel deposition technique have been introduced. However, studies determining the trueness and adaptation of implant-supported crowns made with the technique are lacking. The purpose of this in vitro study was to evaluate the trueness and adaptation of implant-supported zirconia crowns fabricated using additive 3D gel deposition in comparison with zirconia crowns made with the widely used subtractive milling technique. Crowns were fabricated for wide-diameter titanium implants and wide-neck abutments. Self-glazed zirconia (SGZ) crowns were fabricated using 3D gel deposition (n=10) and from 2 brands of zirconia blanks, Wieland and Upcera, using subtractive milling (WMZ and UMZ, n=10). All crowns were digitalized by a scanner, and then 3D deviation analysis was applied. The trueness was assessed by root mean square (RMS). Marginal and internal adaptations were evaluated using the direct-view technique (DT) and replica technique (RT). The results were analyzed by using the 1-way ANOVA and Kruskal-Wallis statistical tests (α=.05). The RMS and marginal discrepancy of SGZ exhibited the lowest values among the 3 groups (P<.05), and the 2 types of milled zirconia crowns had comparable RMS and marginal discrepancy values (P>.05). The internal discrepancy values of SGZ were significantly lower than those of WMZ and UMZ in all regions (P<.05). Compared with the WMZ, UMZ showed comparable internal discrepancy values in the axial and axio-occlusal transition regions (P>.05) but had significantly lower internal discrepancy value in the occlusal region (P<.05). The adaptation of 3 types of wide-diameter implant-supported zirconia crowns can meet the clinical requirements. Compared with the subtractive milling process, 3D gel deposition produced implant-supported zirconia crowns with improved trueness and adaptation.

Magnets have been used to help position dental components, including magnetic mounting plates for articulators and magnetic attachments for implant surgical guides. A magnetically coupled tooth arrangement technique used the fixed reference point of integrated implants to determine maxillomandibular relations and the tooth arrangement, thus improving the efficiency of the clinical appointment. The magnetic framework was screwed into the implants only once for the duration of a clinical appointment. The base was used to complete the tooth arrangement and determine the maxillomandibular jaw relationship.