Management of Buccal Screw Access Hole Positioning for Implant Fixed Complete Dentures: A Report of Two Patients and a Proposed Decision Tree

The present report demonstrated the use of two methods to correct the positioning of buccal screw access holes in both implant- and abutment-level implant-supported fixed complete dentures in two patients. The report suggests that nonaxially tightened abutments (in this report, dynamic abutments), angled multi-unit abutments, and the use of a milled framework with individual crowns aid in masking buccal screw access holes while maintaining the benefits of a screw-retained design. A decision tree is also proposed to facilitate the workflow when faced with such clinical scenarios.

The Application of Angulated Screw-Channels in Metal-Free, Implant-Supported Restorations: A Retrospective Survival Analysis

Angulated screw channels (ASC) allow the clinician to reposition the access hole of screw-retained restorations, improving the design of the rehabilitation and the esthetic outcome. Few clinical studies are available on the efficacy of these restorations, especially at longer follow-ups and with a large number of subjects. The objective of this study was therefore to retrospectively evaluate patients rehabilitated with screw-retained restorations using ASC. The time of delivery and their adherence to the maintenance program was obtained, as well as the characteristics of the restoration and of the patient’s occlusion; a Kaplan–Meier survival curve was then built to investigate the success rate of these restorations and the effects of several variables were evaluated with a Cox model. A total of 105 subjects and 162 implants were enrolled in this study; after 42 months a success rate (92%) similar to what is reported for conventional screw-retained restorations was encountered. Monolithic zirconia restorations (n = 52) had a higher success rate (95%) when compared to partially veneered restorations (n = 53), which suffered a higher number of complications (90%). The other variables had no statistically significant effect. Implant supported prostheses adopting ASC provide a favorable outcome both in the posterior and anterior regions and can therefore be adopted to treat cases where the implant angulation is unfavorable for a conventional screw-retained prosthesis.

Screw-Retained Implant-Supported Fixed Dental Restorations: A Rational Method to Overcome Esthetic Issues with the Screw-Access Hole

Achieving both esthetics and a perfect seal of the screw-access hole in a screw-retained implant-supported fixed dental restoration is a great challenge. From a functional point of view, a perfect seal needs to be obtained to prevent bacterial contamination along the screw access canal and the occlusion shall be addressed. Such a challenging procedure has to be based on a rational analysis of the different materials used. Screw-retained zirconia-based restorations offer a new perspective for esthetic and biocompatible results. The aim of this article is to describe an easy and reproducible clinical procedure to esthetically seal the screw-access hole of screw-retained implant-supported fixed dental restorations.

Advancements toward autonomous access hole detection for urban search and rescue

The collapse of buildings creates voids underneath rubble, where victims may be trapped. First responder crews arriving at a collapse scene are responsible for the location of access holes, among other tasks. Access holes are entry points through which rubble voids may be reached by search and rescue personnel. Previously presented work aimed to autonomously locate such holes, aiding concentration of resources to areas of interest, such as those leading into rubble. The work proposed improves upon existing work by increasing accuracy while reducing total number of detections. A new process is introduced for segmentation of colour and depth images, significantly improving the hole finding system’s accuracy. The ability to score holes based on multiple frames, considering various points of view is introduced. As an added benefit, matching holes across frames allows the algorithm to report holes once per group of matches, rather than once per frame.

Advancements toward autonomous access hole detection for urban search and rescue

The collapse of buildings creates voids underneath rubble, where victims may be trapped. First responder crews arriving at a collapse scene are responsible for the location of access holes, among other tasks. Access holes are entry points through which rubble voids may be reached by search and rescue personnel. Previously presented work aimed to autonomously locate such holes, aiding concentration of resources to areas of interest, such as those leading into rubble. The work proposed improves upon existing work by increasing accuracy while reducing total number of detections. A new process is introduced for segmentation of colour and depth images, significantly improving the hole finding system’s accuracy. The ability to score holes based on multiple frames, considering various points of view is introduced. As an added benefit, matching holes across frames allows the algorithm to report holes once per group of matches, rather than once per frame.

The BEAMISH hot water drill system and its use on the Rutford Ice Stream, Antarctica

During the 2018/19 Antarctic field season, the British Antarctic Survey (BAS) Basal conditions on Rutford Ice Stream: BEd Access, Monitoring and Ice Sheet History’ (BEAMISH) project drilled three holes through the Rutford Ice Stream, West Antarctica. At up to 2154 m, these are the deepest hot water drilled subglacial access holes yet created, enabling the recovery of sediment from the subglacial environment, and instrumenting the ice stream and its bed. The BEAMISH hot-water drill system was built on extensive experience with the BAS ice shelf hot-water drill and utilises many identical components. With up to 1 MW of heating power available, the hot water drill produces 140 L min−1 of water at 85°C to create a 300 mm diameter access hole to the base of the ice stream. New systems and processes were developed for BEAMISH to aid critical aspects of deep access drilling, most notably the creation of cavities interlinking boreholes at 230 m below the surface and enabling water recirculation throughout the deep drilling operations. The modular design of the BEAMISH drill offers many benefits in its adaptability, redundancy, and minimal logistical footprint. These design features can easily accommodate the modifications needed for future deep, clean access hole creation in the exploration of subglacial environments.