Technique tips: The check record

The check record is a simple technique used at the delivery stage of complete dentures that verifies the occlusion.¹ It is an effective technique that requires the use of a pre-occlusal record on the arc of closure to allow the clinician and technician to identify occlusal errors and correct them.² This article highlights the steps required as part of this method and summarizes the relative advantages and disadvantages of this clinical technique.

At the delivery stage, dentures are placed in the patient's mouth and are checked for their fit. The normal process of reviewing the retention and stability of the prostheses is done. The occlusion is checked and if there is a major discrepancy, such as an open bite or major disruption of the occlusion, then this will only be corrected by either removing teeth or returning to a registration in wax on the acrylic baseplate. If the discrepancy is minor then much time can be saved at the chairside by returning the dentures to the laboratory with a registration in wax. The first procedure of a check record is to select pink modelling wax of one thickness, and seal it to the occlusal surfaces of the lower posterior denture teeth (Figure 1).

The wax is softened further by heating and, when in the mouth, the patient is gently guided into their retruded contact position (RCP). The patient is asked to touch the wax lightly and not to allow the opposing teeth to contact. In this way, a pre-contact record is created (Figure 2). This is adjusted so that the patient occludes evenly on these wafers (Figure 3). If the patient breaks through the wax and meets the opposing teeth, this may then lead to the patient moving their jaw as they look for the best occlusal fit. They will then be guided into a wrong registration.

Minimal occlusal forces are used to achieve the pre-contact record on the softened wax, which will therefore promote even intercuspation of all teeth once the dentures have been adjusted.²

The laboratory technician will remount the dentures and registration on an average value articulator or a semi-adjustable articulator (Figure 4). The wax and pin are removed and the articulator is closed showing the premature occlusal contact. This is then adjusted in the laboratory with articulating paper and milling paste (Figures 5 and 6). This would specifically involve grinding selective aspects of the denture teeth. If the denture cusp is high in centric and in excursive positions, the cusp itself is reduced. Pre-centric interferences would require the central fossae and marginal ridges of the opposing tooth to be deepened to accommodate eccentric movements.

In protrusive movements, the tips of the buccal and lingual cusps of the posterior teeth should meet. In situations with heavier posterior tooth contact, but no anterior tooth contact, the distal inclines of the upper cusps and mesial incline of lower cusps should be reduced. If there is a heavier anterior tooth contact with little posterior tooth contact, the incisal and labial aspect of the lower teeth with the palatal surfaces of the upper teeth should be reduced.

On completion, the dentures are delivered to the patient and the occlusion checked in the mouth.

This technique reduces time needed for chair-side adjustments and requires minimal further equipment. When at the trial denture stage, if there appears to be a need for gross occlusal adjustment, the check record can be anticipated. The laboratory technician can be asked to mount the upper finished denture on a split cast. The lab only then needs to mount the lower denture base on the check record taken, streamlining the process even further.^2,3

The check record may introduce possible errors, including the following. An incorrect pre-contact record may be created by adding another step to the denture construction process. The problem may be created by the clinician who may produce an inaccurate wax record. This is likely to be rare as this is a record taken on processed and stable denture bases, which should assist the procedure. Errors are also reduced if the thickness of wax used for registration is less than 3 mm. This will ensure that the patient jaws are recorded in centric relation.¹

Loss of working side contacts is possible if gross adjustments of the occlusion are made. Such large changes and adjustments are not appropriate for the check record stage and should be identified at the trial denture stage.¹

Conclusion

The check record is a useful and relatively quick method to alleviate occlusal discrepancies at the time of denture delivery. Often, resetting teeth at wax try in is required for large discrepancies, but small adjustments may still be needed at the denture delivery stage. As the denture is processed, the stability of the processed acrylic bases offers a good platform to adjust occlusal errors and increase the chance of creating a functional set of complete dentures.