Martin Schimmel presents a case demonstrating the clinical application of the CM Loc Flex implant

A female 67-year-old patient with an edentulous upper jaw was selected for this clinical procedure. She had received four Straumann Standard Implants (SLA active surface, 8mm length, regular neck, 4.1mm diameter, Straumann, Switzerland) in March 2011.

Figure 1 (main picture above): Clinical scenario with malaligned implants and Locator attachments; the implant UL2 was already lost. The attachment showed severe signs of wear and needed to be replaced

The implants has been placed following the recommended surgical protocol for edentulous patients in the maxilla without augmentation procedures, but due to insufficient local alveolar bone mass they had been placed in an unfavourable angle for the subsequent prosthetic restoration.

Figure 2: Unfavourable position of the secondary parts of the Locator attachments. They were removed with the appropriate counter-torque

One implant in the region of the UL2 was lost (Figure 1) and another implant was placed in the region in September 2015. The implants were loaded using Locator attachments (Zest Anchors, USA) to retain an implant supported overdenture (IOD).

Figure 3: The CM Loc Flex case guide helped determining the orientation and height of the future abutment. In the present picture, the case guides were co-linear with the implant, indicating a significant divergence. The mucosal height was read on the marks of the CM Loc Flex case guide.

It was then decided to change the IOD retaining attachments in order to establish sound mechanical and biological conditions.

Figure 4: The CM Loc Flex case guide helped determine the angle between the future abutments in the sagittal and anterior plane

At first, the Locator attachments were removed (Figure 2) and the appropriate height of the CM Loc Flex abutments were selected (Figure 3). The converging angle between the implants was verified three-dimensionally using the CM Loc Flex case guide (Figure 4).

Figure 5a: The CM Loc Flex abutments was carefully placed into the implant by hand using the CM Loc screw driver

It became evident that the angle between the implants exceeded 10° but not more than 30°; therefore the CM Loc Flex was selected for this patient. The treatment plan aimed to arrange the abutments parallel to the occlusal plane to improve the clinical situation.

Figure 5b: The minimum distance of 1mm between mucosa and active part of the abutment was respected to avoid trauma of the peri-implant soft tissue

The CM Loc Flex abutments were placed carefully into the implant and screwed in by using the CM Loc Flex screw driver (Figures 5a and 5b). The final torque of 35Ncm was applied with the CM torque wrench (Figure 6).

Figure 6: The final torque of 35Ncm was applied on the CM Loc Flex with the CM torque wrench

Subsequently, the CM Loc Flex aligners were placed onto the abutments and were firmly moved on to the fixed position, which is clinically well defined and within the axis of the implant (Figure 7). It clicks when reaching the intended position.

Figure 7: CM Loc Flex aligners in place

It was planned to first align the two central abutments and to align the remaining abutments in a second step, as the capsules of the employed cement contain only enough cement for two abutments.

Figure 8: Close-up picture of the UR4 CM Loc Flex aligner. The filling funnel was properly seated in the central filling hole. The aligner is co-linear with the implant axis

The correct seating of the aligners was controlled by verifying that the aligner’s filling funnel was properly seated in the central filling hole of the CM Loc Flex (Figure 8).

Figure 9: Clinical picture of the injection process of the composite cement into the CM Loc Flex aligner

The next clinical step comprised the injection of composite bonding cement. In this case, Relyx Unicem self-adhesive universal resin cement (3M ESPE) was used. The injection cannula was placed on the first aligner, the cement was injected and it was well taken care of that the cement leaked out of the two vent holes on the top of the abutment (Figure 9).

Figure 10: The cement leaked out of the two vent holes on the top of the abutment. The working time of the proposed composite cement (according to the IFU) was sufficiently long to fill the aligner on a second abutment with the same capsule

Using the same Relyx capsule, a second aligner was charged during the working time of the cement as described in the IFU (Figure 10).

During the specified working time of the 3M ESPE Relyx Unicem, the alignment of the first two abutments was performed. Therefore, the CM Loc Flex aligner was tipped into the opposite direction of the implant axis in order to find the movable position of the aligner. Subsequently, the abutments were aligned:

  • Parallel to each other both in the buccal-lingual and mesial-distal planes
  • Perpendicular to the occlusal plane.
Figure 11: The CM Loc Flex aligners were carefully moved into their second position that allows aligning the abutments

Subsequently, the remaining two CM Loc Flex aligners were filled and aligned (Figure 11).

Figure 12: Clinical situation after removal of the aligner at the UL quadrant

The exact same steps were repeated to align the implants in the regions UR4 und UL4 parallel to the central aligners. The alignment of the abutments was verified in all three dimensions (Figure 12).

Figure 13a and 13b: Clinical situation after cleansing of the abutments at the UL quadrant

After allowing complete curing of the cement, the aligners were removed (Figure 13a) and the abutments cleaned (Figure 13b). The procedure was performed uneventfully; it proved to be simple and well described in the current version of the IFU.

Figure 14: The locators housing were removed from the denture base and the space requirements for the CM Loc abutments were respected

The following steps of fixing the retentive parts into the existing denture are clinically well established and do not differ to other stud-type IOD-attachment systems. The first procedure required the removal of the Locator housings from the denture, which was performed with the CM Loc housing extractor (Figure 14).

Figure 15: The CM Loc housings were placed on the abutment to allow adjusting the denture base

Subsequently, the CM Loc impression part were placed onto the abutments and it was verified that there was sufficient space in the denture base for them to be incorporated (Figure 15a).

Figure 16: The relining impression with CM Loc housings with mounted CM Loc retention inserts for further processing in the dental laboratory

As the placement of the CM Loc impression part would have required substantial removal of the metallic framework, it was decided to use the CM Loc housings with mounted CM Loc retention inserts for the relining impression (Figure 15b).

Figure 17: The finished and polished denture base with the CM Loc housings with mounted CM Loc retention inserts (yellow, extra-low)

The reline impression was used employing Impregum soft polyether impression material (3M ESPE) (Figure 16).

During the setting time of the Impregum, the denture was placed into the mouth and the patient was asked to remain in central occlusion until the material was set.

Figure 18: Clinical picture of the IOD retained by CM Loc Flex abutments

The impression was disinfected and sent to a dental laboratory for a reline and incorporation of the CM Loc Pekkton housings.

The IOD retained with CM Loc Flex abutments and housings with extra-low retention force inserts was delivered on the same day (Figures 17 and 18).

Applicability of the IFU (version 11.2015)

In the first part of the current documentation, the feasibility of the clinical steps as described in the IFU for the CM Loc Flex abutment was demonstrated. This description refers, among others, to the chairside alignment of the attachment and lab-based fixation of the housing in the denture base, which is (from a clinician’s point of view) the technically most demanding procedure.

The IFU defines very well the criteria for selecting the CM Loc Flex, thus the three-dimensional orientation of the supporting implants. The CM Loc Flex abutment offers the clinician and the supporting dental technician a very wide spectrum of
clinical applications.

Figure 19: Final result

Conclusion

The current IFU describes the clinical and technical procedures for the CM Loc Flex abutment of Cendres+Métaux SA. The IFU allowed me to apply the described procedures from first use after reading the IFU attentively. No deviation from the described procedures was necessary in order to achieve a highly satisfying clinical result.

Disclaimer

The patient provided informed written consent to publish her pictures. The surgical treatment was paid for by the patient. Martin Schimmel and Patrick Zimmermann have no direct or indirect financial relationship with Cendres+Métaux SA and did not receive benefit in kind or cash for the current report.

The current case report was part of an agreement between the Division of Gerodontology (University of Bern) and Cendres+Métaux SA for the documentation of five clinical cases with the CM Loc attachment systems. Cendres+Métaux SA provided the parts and indemnified the Division of Gerodontology and the dental laboratory (Zahnmanufaktur).