The efficient and accurate recording of maxillomandibular relations is an important step in prosthodontic treatment,
1
with the occlusion directly affected by the accuracy of these records.2
Different methods have been proposed to perform this step, each with its advantages and limitations.3
The methods most commonly used have been gothic arch tracing and the wax recording procedure.4
Originally, these were intended for complete dentures1
,3
,4
but more recently have been adapted for implant-supported fixed prostheses.5
,6
The wax recording method for implant-supported prostheses consists of an occlusion rim that is secured to the implants by using impression transfers or gold cylinders.
5
This technique facilitates the recording of centric relation and occlusal vertical dimension because the occlusion rims are rigidly attached to the implants with coping screws.5
A shortcoming of this approach is that the coping screws need to be removed every time the occlusion rims require modification. If multiple adjustments are needed, the repeated screw removal can be frustrating to both the clinician and patient.The verification of the definitive casts is a recommended step to ensure the longevity of implant-supported prostheses,
7
, 8
, 9
, 10
and different methods have been recommended for this purpose, all aiming to verify the tridimensional position of the implant replicas in the definitive cast.8
,11
,12
This article describes a straightforward technique of fabricating an overlay occlusion rim which uses the implant indexing device as a foundation. This approach facilitates the recording of the maxillomandibular relations because it permits the removal of the occlusion rims without removing the coping screws and saves clinical time because the maxillomandibular relationship record can be performed at the same time as verification of the definitive cast.Procedure
- 1.Fabricate an implant indexing device with parallel axial walls, a flat occlusal surface, and sufficient material surrounding the impression transfer copings (ACTDT; Zimmer Biomet). If cantilevers are anticipated, extend the implant indexing device as needed.
- 2.Evaluate the implant indexing device intraorally (Fig. 1) and verify the accuracy of the definitive casts. If a discrepancy is found at this stage, a new definitive impression is required.
![Figure thumbnail gr1]()
Figure 1Intraoral photograph of maxillary and mandibular implant indexing device. Note flat occlusal surfaces and parallel axial walls. - 3.Remove the implant indexing device from the patient’s mouth and spray it with a disinfecting solution (Cavicide1; Metrex). Replace the transfer screws (SCDTS; Zimmer Biomet) with coping screws (SCTS; Zimmer Biomet). Fix the implant indexing device to the verified definitive cast with the coping screws. Posteriorly, block the screw-access holes with polytetrafluorethylene (PTFE) tape or cotton pellets.
- 4.Embed the implant indexing device up to its middle in the zinc pellet container of a pressure molding device (BioStar; ScheuGroup), making sure to cover the undercuts and irregularities with zinc pellets. Copy the verification device surface with a thermoplastic polymer (1 mm/125 mm Round Clear Splint Biocryl; Great Lakes Orthodontics); do not remove the plastic lining because it will act as a separating medium (Fig. 2A).
![Figure thumbnail gr2]()
Figure 2A, Thermoplastic polymer pressure molded directly over mandibular implant indexing device; note lining plastic as separating medium. B, Lining plastic removed with sharp instrument. - 5.Carefully remove and trim the pressure molded record base from the implant indexing device. Smooth the borders and any irregularities with a fine laboratory tungsten carbide cutter (H251ACR; Komet USA) and an abrasive buffing wheel (9485F; Komet USA). Using a sharp instrument, remove the plastic lining (Fig. 2B). After the adjustments, verify that the pressure molded record base does not rock and can be easily removed and reseated on the implant indexing device.
- 6.Fabricate an occlusion rim over the pressure molded record base (Fig. 3). Record the maxillomandibular relations by using the overlay occlusion rims (Fig. 4).
![Figure thumbnail gr3]()
Figure 3Mandibular implant indexing device and overlay occlusion rim.![Figure thumbnail gr4]()
Figure 4Intraoral photograph of overlay occlusion rims used for maxillomandibular relationship record.
References
- The maxillomandibular relationship of centric relation.J Prosthet Dent. 1959; 9: 922-926
- Recording the retruded contact position: a review of clinical techniques.Br Dent J. 2004; 196: 395-402
- A review of some of the problems associated with centric relation.J Prosthet Dent. 1952; 2: 307-319
- Factors influencing centric relation records in edentulous mouths.J Prosthet Dent. 1964; 14: 1054-1065
- Implant prosthodontics.2nd ed. Mosby, St. Louis1999: 15-17
- An alternative method for the production of accurate casts and occlusal records in osseointegrated implant rehabilitation.J Prosthet Dent. 1987; 58: 694-697
- The use of an extraoral verification template for dental implant-supported prostheses.Oral Implantol. 2002; 28: 184-188
- Implant verification cast--a predictable restorative system in implant prosthodontics.J Calif Dent Assoc. 2010; 38: 571-581
- A Technique to verify or correct analogue position and soft tissue profile on an implant working cast.J Prosthet Dent. 2009; 102: 137-139
- One-step implant index verification and maxillomandibular relationship.Implant Dent. 2002; 11: 159-161
- Dental gypsum verification jig to verify implant positions: a clinical report.J Oral Implantol. 2014; 40: 495-499
- Implant transfer coping verification jig.J Prosthet Dent. 1989; 61: 601-602
Article info
Publication history
Published online: October 28, 2020
Identification
Copyright
© 2020 by the Editorial Council for the Journal of Prosthetic Dentistry.
30494-7&id=gr1.jpg){kind=link}
30494-7&id=gr2.jpg){kind=link}
30494-7&id=gr3.jpg){kind=link}
30494-7&id=gr4.jpg){kind=link}