Multi-part endosseous dental implants are made up of small, complex, precision components, including the abutment, which have to meet very strict dimension and tolerance requirements. Abutment blanks, or prefabs, are used to quickly produce customised abutments and are delivered to dental laboratories and milling centres with an industrially prefabricated connection geometry that is compatible with multiple implant systems. Dental laboratories and milling centres then use digital CAD/CAM systems to mill the abutment to fit an individual patient’s needs.
There is no room for error and abutment blank manufacturers use multisensor coordinate measuring machines (CMMs)
to perform a documented inspection of each abutment blank they produce. It is also crucial for manufacturers to achieve high levels of output, so they rely on CMMs that combine fast throughput with accuracy to perform serial measurements.
High measuring throughput
Rapid inspection is a key productivity driver for abutment blank manufacturers and Hexagon has developed its OPTIV M multisensor CMMs
to be configurable for their specific throughput demands. The OPTIV M with the Throughput capability package connects intelligent sensor and software technologies and offers differentiated possibilities to increase measuring throughput and productivity on the basis of three performance levels: Green, Blue and Chrome, with Chrome ensuring the fastest material-independent throughput.
Multisensor solution for universal 2D and 3D measuring tasks
The vision sensor uses high resolution and high point density to measure all edges of the connection geometry visible in the back light or top light, namely the diameter and the overall size of the hexagon of the anti-rotation device.
Visible edges of the connection geometry are measured using the vision sensor.
When inspecting abutment blanks it is crucial to measure discrete points to determine the geometric positional relation (parallelism) of functional surfaces. The OPTIV M Green with the Throughput capability package gives manufacturers a choice of the HP‑TM touch-trigger probe or the laser triangulation sensor (OPTIV LTS) used in single-point mode. The OPTIV M Green with the Throughput capability package also ensures the position of the screw channel can be measured in relation to a defined reference surface using the touch-trigger probe.
Evaluation of three-dimensional position deviations is accomplished by measuring discrete points using the HP‑TM touch-trigger probe or the laser triangulation sensor (OPTIV LTS).
Extended scanning function for quick form and profile measurements
The OPTIV M Blue with the Throughput capability package takes throughput up a notch, by using the HP‑S‑X1 tactile scanning probe to determine the form deviation of the screw channel. The HP‑S‑X1 tactile scanning probe has a measuring rate of up to 1000 points per second, giving it a major speed advantage over touch-trigger probes.
The form deviation of the screw channel is determined by tactile scanning using the HP‑S‑X1 scanning probe.
The package can also deploy the laser triangulation sensor (OPTIV LTS) scanning function to measure the surface form deviation (flatness) of some functional surfaces, switching to the HP‑S‑X1 scanning probe when the greatest accuracy is required.
The flatness of some functional surfaces is determined by scanning using the laser triangulation sensor (OPTIV LTS). If higher accuracy is required, the HP‑S‑X1 scanning probe will solve this measuring task.
Material-independent, high-resolution surface measurement
The OPTIV M Chrome with the Throughput capability package deploys Hexagon’s chromatic confocal white light sensor (CWS) to offer the highest level of throughput. The CWS works largely independently of the surface and allows high-resolution measurement of reflective prefab materials with very low measurement uncertainty. It enables surface scanning at maximum speed while meeting the highest tolerance requirements. Moreover, the CWS is able to measure accurately and quickly on inclined surfaces and the steep flanks of the prefabs (angular acceptance up to ± 45°).
The chromatic white light sensor (CWS) measures reflective prefab surfaces with very low measurement uncertainty and high measuring speed. The CWS guarantees valid measurement results on inclined surfaces and steep flanks with angles of up to ± 45°.
In addition, OPTIV M CMMs equipped with the OPTIV Dual Z technology
achieve optimum accessibility to the measuring positions on the workpiece by moving the inactive sensor out of the measuring range. This reduces the number of required probe changes and, consequentially, further increases batch measurement throughput.
Enhancing speed with multisensor technology
OPTIV M CMMs’ multisensor technology makes it easy to use image processing sensors, optical distance sensors and tactile sensors to capture all the geometric characteristics of a prefab within a single inspection cycle. And because operators are not switching between several single-purpose measuring machines, they can collect the measuring points for a complete dimensional workpiece analysis and statistical process control within a very short time.
Close-to-production measuring saves time
The capture and evaluation of measurement data directly on the production line enables quick process control, which in turn enables rapid remedies to be taken that reduce scrap. OPTIV M combines intelligent technologies for automation integration and networking of the measuring machine in production environments.
Statistical process control (SPC), gauge capability and process capability
OPTIV M CMMs transfer measurement data via a standardised data interface (AQDEF) to the Q‑DAS statistical analysis software. The Q‑DAS O‑QIS software visualises measurement data in real-time and monitors them statistically. In case of violations of SPC alarm criteria, the CMM operator will be informed systematically and can intervene in the manufacturing process by taking corrective action, before generating expensive scrap.
Inspecting 100% of abutment blanks during production ensures sustainable compliance with critical product characteristics. Confidence that the OPTIV M CMM is achieving optimum measuring results is provided by the Q‑DAS solara.MP software, which performs statistical measurement analyses to prove the measurement system capability (capability indexes Cg and Cgk).
The proof of process capability (capability indexes Cp and Cpk) is provided using the Q‑DAS qs‑STAT software. These analyses allow conclusions to significant influences, which are due to different production machines, prefab batches and temperatures. Q‑DAS qs‑STAT clearly visualises these influences and evaluates them to derive improvement and cost-saving potentials.
Q‑DAS statistical analysis software: The Q‑DAS O‑QIS software allows real-time visualisation and SPC alarm monitoring of the inspection of abutment blanks during production.
With PC‑DMIS Inspect Pallet, the CMM operator can quickly and easily configure predefined PC‑DMIS measuring routines for a pallet run. During the pallet run, the dimensional accuracy of the measured blanks is displayed with simple pass/fail symbolism.
Automated pallet measurement
Using pallets to automate the measuring procedure results in more efficient quality control, undertaken close to production. The pallets can be prepared away from the machine, thereby reducing CMM downtime associated with setup. In addition, an automatic measuring cycle makes it possible to measure larger batches more quickly without any operator intervention.
gives the production-level CMM operator an interactive graphical user interface, which allows predefined PC‑DMIS measuring routines to be selected and set up for the pallet run. The intuitive software enables quick definition of pallet parameters, such as alignment, fixture pattern, offsets and run parameters. Pallets qualified in this way can then be changed within a few seconds without the need for re‑referencing.
Standard-compliant process validation
The quality of the abutment blanks has to be documented seamlessly, and this documentation has to be both traceable and tamper-proof, with national and international standards defining the requirements for electronic records and signatures. The Q‑DAS statistical analysis software complies with the requirements for validation, according to the standards of the American 21 CFR Part 11 and the European GMP guideline Annex 11.
helps quality managers to work towards process compliance by enabling them to trace changes to previously protected measuring routines. The software pursues a role-base concept. Programmers can certify measuring routines and subsequently also modify them at any time. Any modifications to a protected measuring routine are tracked in a traceable way and displayed chronologically in the Protect Log Viewer. This simplifies the audit of certified measuring routines, which have already been released for the production environment. Users who have been assigned the role of the operator can only execute certified measuring routines.
With PC‑DMIS Protect, the permission to change measuring routines can be limited to an authorised group of persons. Changes to a previously certified, i.e. protected measuring routine, are tracked in a traceable way.