Maxillomandibular relationship record for complete arch/mouth implant restorations using putty-elastomeric occlusion rim at healing abutment level.

INTRODUCTION: Recording of the maxillomandibular relationship (MMR) in implant complete arch restorations usually necessitates removal of the healing abutments to attach the record bases, which makes the procedures tedious and time-consuming.
MATERIALS AND METHODS: This article describes the procedure of recording of MMR for complete mouth rehabilitation with the help of the putty elastomeric record base cum occlusion rim reinforced with the acrylic resin framework. This technique records the MMR without removing the healing abutments from mouth and without attaching the acrylic-resin record base with wax occlusion rim.
RESULTS: The use of putty-elastomeric occlusion rim provides stable interocclusal records for implant supported complete arch (or mouth) rehabilitation.
CONCLUSION: Maxillomandibular relationship records made with the present technique is less time-consuming and accurate with less chances of distortion of the MMR records.

Introduction

Implant supported complete mouth/arch rehabilitation of the completely edentulous patient follows the principles of conventional complete dentures.[1] The series of clinical steps such as accurate impressions and maxillomandibular relation (MMR) records are essential to achieving the passive fit of the final prosthesis on the implants.[2] Establishing the MMR records is generally recorded with the help of resin record base and wax occlusion rim.[3] However, for the implant supported the prosthesis, record base must be reinforced in different ways to make it rigid and fit into the multiple implants to record the MMR. The record bases can be reinforced with gold cylinders,[2] the plastic healing caps, abutments or the impression copings.[4] Special components also have been fabricated for this purpose by Kokubo and Ohkubo.[5] However, these procedures can be time-consuming because the healing abutments need to be removed, and separate attachments needed to be attached for the securing of the record base. When the implant prosthesis interface is subgingival, the gingival tissue may collapse, creating difficulties in seating the reinforcing components and resulting in discomfort to the patient. Rungcharassaeng and Kan[6] described a technique to fabricate the record base in light activated resin material and wax occlusion rim to record the MMR at healing abutment level. Papaspyridakos and Lal[7] described a simple technique to record MMR with the help of the existing denture with existing vertical relation.

This article demonstrates the use of putty-elastomeric occlusion rim instead of wax acrylic resin record base and wax occlusion rim which provides more accurate and stable interocclusal records for implant supported full arch or complete mouth rehabilitation. This technique establishes a stable record base without the necessity of removing the healing abutments and without fabrication of resin record base and wax occlusion rim.

Procedure

At the time of stage II surgery (uncovering), place titanium healing abutments (EZ Hi-Tec Implants, Herzlia, Israel) of appropriate heights in the patient's mouth to prevent the soft tissue from closing over the implant [Figure 1a]

Figure 1

(a) Intraoral view at healing abutment stage, (b) definitive impression

When the surgical site is completely healed, remove the healing abutments and replace them with the impression copings (EZ Hi-Tec Implants, Herzlia, Israel). Prepare a custom tray for making the impression with open tray technique. Make an impression in the custom tray with polyvinyl siloxane impression material (Aquasil putty-light-body, Dentsply International, York, Pa.) [Figure 1b]

After complete setting of the impression, unscrew the impression copings, and remove the impression from the patient's mouth. Connect the implant lab analogs (EZ-Hi-Tec Implants, Herzlia, Israel) to the copings in the impression. Replace all the healing abutments back in the mouth on the respective implants

Inject a mix of polyvinyl siloxane soft tissue simulating material (Gi-Mask, Coltene/Whaledent Inc., Mahwah, NJ, USA) around the implant lab analogs in the impression and allow the material to polymerize

Pour a mix of type IV gypsum material (Ultra-rock, Kalabhai Karson, Mumbai, India) into the impression. After complete setting of the type IV gypsum, unscrew all the impression copings from the impression and remove the impression from a definitive cast [Figure 2a]

Figure 2

(a) Definitive cast, (b) horse-shoe shaped resin framework

Prepare a horse-shoe shaped autopolymerizing acrylic resin framework with a vertical height of approximately 10–15 mm and thickness of 3–5 mm as shown in Figure 2b. Note that the resin framework should cover all the implants on both the sides

Apply a tray adhesive to all the surfaces of the resin framework. Mix the condensation silicone putty (Zeta Plus, Zhermack, Badia Polesine, Italy) with the universal catalyst and apply it on all the surfaces of the resin framework to prepare an occlusion rim. At the same time ask your assistant to mix a light-body impression material with the catalyst and apply it on the surfaces of all healing abutments intraoally and make single step putty-wash impression of the healing abutments by placing the framework intraorally covering all the surfaces of the healing abutments (with least flange extensions) [Figure 3a]. Note that the polyvinyl siloxane or polyether putty also can be used instead of condensation silicone to prepare the elastomeric occlusion rim

Figure 3

(a) Putty-elastomeric record base cum occlusion rim, (b) intaglio surface of record base

After complete setting of the putty and light-body, remove the entire rim and examine the impression surface for defects and voids [Figure 3b]

Reseat the putty-elastomeric occlusion rim to check the stability and tentative incisal height of the maxillary teeth [Figure 4a]. Adjust vertical relation by reducing the rim with a knife and trimming the underlying resin framework with a carbide bur [Figure 4b]. If increase in occlusion rim height is required, a small amount of putty can be added on the occlusal surface

Figure 4

(a) Recording vertical relation. White lines indicate stepwise adjustment of vertical relation, (b) occlusion rim can be reduced in height by cutting the putty occlusion rim and trimming resin framework

In case of complete mouth rehabilitation (including implants in both the arches), repeat point 7, 8, and 9 in the opposite arch and adjust the vertical relation

Once the vertical relation is recorded, train the patient to close the mandible in centric relation.[1] Add small amount of light-body condensation silicone (Zeta Plus) on the occlusal surfaces of teeth and the putty on occlusal surface of the adjusted rim and ask patient to close mandible in previously guided centric relation position at the established vertical relation [Figure 5a]. Examine the opposite arch indentations for the defects and voids [Figure 5b]

Figure 5

(a) Centric relation recorded by adding putty and light-body on the opposite arch at established vertical relation, (b) opposite arch indentations

Mount the maxillary cast on the semi-adjustable articulator (A7 Plus Articulator; Bioart, Sao Carlos, SP, Brazil) with the help of face bow transfer and the mandibular cast by using the MMR [Figure 6a and b]

Figure 6

(a) Mounting of casts, (b) removal of maxillomandibular relation, (c) fabrication of metal-ceramic restorations

Proceed with the fabrication of the metal/ceramic/metal-ceramic restorations [Figure 6c] and cement/screw it in a conventional manner. Note the 1-year follow-up photograph and orthopantomograph of the patient [Figure 7a and b].

Figure 7

(a) Postoperative photograph, (b) postoperative orthopantomograph

Discussion

The implant components used to illustrate this article are from the EZ Hi-Tec Implants component system (EZ Hi-Tec Implants, Herzlia, Israel), but the procedure can be used with comparable components from another implant system. Most of the techniques use methods to secure the record bases to the implants to record the accurate MMR results in time-consuming procedures. This technique does not require fixation of the record bases to the components which save the chair-side time considerably. However, Rungcharassaeng and Kan[6] uses light polymerized resin record bases and Papaspyridakos and Lal[7] used existing dentures at abutment level in which fixation of the record bases to the implant components is not required. This technique also used a similar concept but using reinforced putty-elastomer instead of resin record base or the existing dentures. The putty-elastomer record base cum occlusion rim is more stable and accurate than resin record base and wax occlusion rim. This is less time-consuming procedure than all other previously described methods to record MMR because fabrication/reinforcement of the record bases or repeated removal/insertion of healing abutments is not required. Clinical expertise is required to prepare and adjust the elastomeric record base cum occlusion rim.

Conclusion

Maxillomandibular relationship records made with the present technique is less time-consuming and accurate with less chances of distortion of the MMR records