|Year : 2013 | Volume
| Issue : 3 | Page : 120-124
Interocclusal records in fixed prosthodontics
Balvinder Singh Saluja, Divya Mittal
Department of Prosthodontics, GNDDC, Sunam, Punjab, India
|Date of Submission||30-Sep-2013|
|Date of Acceptance||29-Oct-2013|
|Date of Web Publication||12-Dec-2013|
Department of Prosthodontics, GNDDC, Sunam, Punjab
Source of Support: None, Conflict of Interest: None
The precise relation of maxillary and mandibular casts is an essential step in developing accurate occlusion in fixed prosthodontics. When an adequate number of opposing teeth and stable intercuspation exist, direct occlusion of the casts is the most accurate method of articulation. In the absence of definitive occlusal contacts for direct relation of the casts, an interocclusal record is required. This becomes even more important when the distal tooth in the arch is also an abutment in the fixed partial denture. This article reviews various materials and techniques for recording interocclusal relationship in fixed prosthodontic procedures.
Keywords: Anterior stop, interocclusal records, lucia jig, vertical dimension
|How to cite this article:|
Saluja BS, Mittal D. Interocclusal records in fixed prosthodontics. Indian J Oral Sci 2013;4:120-4
| Introduction|| |
Interocclusal records are the means whereby the inter-arch relationships are transferred from the mouth to an articulator.  Interocclusal records are the most important maxillomandibular records used to transfer interarch relationships from the mouth to an articulator. Accurate interocclusal records minimize the need for intraoral adjustments during prosthesis delivery and are essential in providing high-quality fixed restorations and reducing overall treatment time and cost. A clinician's ability to relate and mount casts accurately will have a greater impact on the quality of a restoration than the programming of an adjustable articulator. 
| Indications for Interocclusal Records|| |
- If the patient has an adequate number of teeth and a stable intercuspal position, no signs and symptoms of trauma to the occlusion and the goal of treatment is to maintain pre-treatment intercuspation and occlusal vertical dimension (OVD), then the most accurate method of articulation is to occlude opposing casts by hand, without intervening bite registration material. Recording material placed between teeth in this case often prevents casts from maximal intercuspation and an interocclusal record is registered at an increased OVD.
Mounting casts in the maximum intercuspal position (MIP) facilitates treatment and the majority of cases fall within the MIP category.
- If the planned restorations involve terminal teeth in the arch, an interocclusal record is needed as there is insufficient horizontal stability of the casts for hand articulation and mounting.
For opposing casts to occlude accurately, a tripod of vertical support and horizontal stability must exist between the casts. To ensure that there are sufficient numbers of occluding teeth to mount working and opposing casts in MIP, as well as horizontal stability, casts must reproduce the full dental arch.
- When terminal teeth are prepared for crowns or fixed partial dentures and the third leg of the tripod is lost, the dentist must fabricate an interocclusal record to recapture the lost leg and create a tripod of vertical support to mount casts accurately. 
| Types of Interocclusal Records|| |
Basically, there are two main categories of interocclusal registration:
- Centric interocclusal records
- Eccentric interocclusal records.
The centric interocclusal records are further classified as follows:
- Maximum intercuspation position (MIP) records: it is the interocclusal registration made at maximal intercuspation of the existing dentition
- Retruded centric position (RCP) records: it is the interocclusal registration made at the centric relation of the mandible. It is generally indicated when the change in the vertical dimension is to be anticipated and use of facebow is indicated in relating the maxillary model to the upper member of the articulator.
The eccentric interocclusal records are further classified as follows:
- Lateral excursive records: the lateral excursive registration records the lateral excursive maxillomandibular relationship and is performed without occlusal contact. These records are used to set the condylar elements of an arcon semi adjustable articulator
- Protrusive interocclusal records: it registers the maxillomandibular relationship during protrusion of mandible. It is generally indicated when the use of a non-arcon articulator is anticipated. 
| Materials Used for Interocclusal Records|| |
The Ideal requirements of bite registration material are as follows:
- The materials should offer limited resistance before setting to avoid displacing the teeth or mandible during closure, whereas after setting, it should be rigid or resilient, with minimal dimensional change
- It should be easy to manipulate with no adverse effects on the tissues involved in the recording procedures
- It should accurately record the incisal and occlusal surfaces of teeth
- It should be verifiable. ,,,,,,
| Materials Used|| |
Various materials are used for bite registration such as waxes, zinc oxide containing pastes (eugenol containing and non eugenol pastes) and dental plaster, modeling compound, acrylic resin, elastomeric materials and the combination of materials.
It is the most versatile and most commonly used interocclusal recording material. The reason for its versatility is its easy manipulation and when softened, it softens uniformly and remains soft for an adequate working time. However, it is dimensionally inaccurate interocclusal recording material as it has a high coefficient of thermal expansion and high resistance to closure, which lead to inaccuracies while registration is made. Distortion of wax is also very common due to release of internal stresses, thus, leading to inaccuracies in the record. Therefore, it has been classified as most inaccurate material among the interocclusal records studied. ,,,,,
Zinc oxide eugenol paste
It is generally used as interocclusal recording material. Because of the fluidity of paste before setting, it offers minimal resistance with mandibular closure and becomes rigid after it sets finally. However, zinc oxide eugenol pastes have a lengthy setting time, significant brittleness; they stick to the teeth and have unreliability to reuse. As it sets by chelation reaction, the by - products formed may undergo evaporation leading to dimensional change. Vital portions of the record can be lost through breakage on removal from the mouth. Once zinc oxide eugenol record has been used to mount the casts, it is rarely used again. Unless trimmed, flash around the teeth can prevent the accurate seating of casts. Thus, it is advisable to use a minimal amount of zinc oxide eugenol to avoid excess flash. Therefore, zinc oxide eugenol was added to wax impression in a very thin layer to improve poor detail transfer and displacement of wax. ,,,,
In corrected wax interocclusal recording material, interocclusal record made with wax is corrected with zinc oxide eugenol material. It improved the detailed recording and displacement of wax, but caused the increase in the vertical dimension. While making record with corrected wax, they used double sheet of the base plate wax and the record is made. After the removal of record from mouth, thin layer of zinc oxide eugenol was applied over the wax record and placed intraorally until material is hardened. ,,,,
The metallized wax wafers (aluminum particles) are found to be much more accurate than non-metallized wax as the addition of metal particles (aluminum) to the modeling wax make it more conductive which may lead to variation in the accuracy of the record. ,,
Elastomers are the most dimensionally stable materials till yet. Elastomers as interocclusal record materials consistently yielded the least error among the materials studied. They are easy to manipulate and offer little or no resistance to closure, set to a consistency that makes them easy to trim without distortion, and accurately reproduce tooth details. Furthermore, among the elastomers, addition silicones exhibit least amount of distortion. The excellent dimensional stability of addition silicones is attributed to the fact that it sets by addition polymerization reaction. Therefore, no by-products and no loss of volatiles occur in addition silicones. Accuracy, minimal resistance to closure and easy manipulation are the main advantages of addition silicones as interocclusal recording material. However, its major disadvantage is that any compressive force exerted on these materials during mounting procedures may cause inaccuracies during mounting of the casts. Spring action found in these materials may cause inaccuracies during mounting of the casts. The spring action found in these materials caused the articulated cast to open in centric relation position. Thus, the records should be trimmed and carefully seated over the occlusal surface to minimize the negative spring action. ,,,,
Polyether interocclusal registration material consists of the basic impression material augmented by plasticizers and fillers. The advantages of this material as an interocclusal registration material are accuracy, stability after polymerization and during storage, fluidity and minimal resistance to closure, can be used without a carrier. Disadvantages are that resiliency and accuracy may exceed the accuracy of the plaster casts. Both of these factors can interfere with the placement of the plaster cast into the recording medium during mounting procedures. The records are trimmed to remove excess material and preserve only the teeth indentations, avoiding distortions. ,
Impression plaster is basically plaster of Paris with modifiers. Modifiers accelerate setting time and decrease setting expansion. Records of impression plaster are accurate, rigid after setting, and do not distort with extended storage. It is difficult to handle because the material is fluid and unmanageable prior to setting. The final interocclusal record is brittle. ,,,,
The most frequent application of acrylic resins for interocclusal records is in the fabrication of single stop centric occlusion records. Acrylic resin is both accurate and rigid after setting. Disadvantages of acrylic resin as an interocclusal registration material include dimensional instability due to continued polymerization resulting in shrinkage; rigidity of the material can damage plaster cast and dies during mounting on the articulator. ,,,,,
Modeling compound, which becomes rigid upon setting, has been used to fabricate segmental interocclusal records. Two potential errors associated with its use include the following:
- Flow of the material over axial surfaces of natural teeth and over soft tissues, which invites errors in repositioning working casts within the bite registration and
- Abrasion of working cast dies during mounting and subsequent removal of the record. ,,
He used bilateral manipulation to guide the mandible to centric relation. In this technique, dental chair is reclined and patient head is cradled by dentist. Thumbs are placed over the chin and fingers are resting firmly on the inferior border of mandible. Dentist exerts downward pressure on the thumbs and upward pressure on the fingers, manipulating the condyle-disk assembly into their fully seated positions in the mandibular fossae. ,
Anterior stop technique
The anterior stop centric relation record is accomplished with an anterior deprogramming appliance. This allows separation of the posterior teeth immediately prior to centric relation record fabrication. This deprograms the influence of the posterior dentition by creating a platform that the incisal edge of the mandibular central incisor contacts. This provides posterior space for the interocclusal material and the carrier.
This result in the patient "forgetting" established protective reflexes that are reinforced each time the teeth come together, making mandibular hinge movements easier to reproduce. The resulting anterior stop acts as a fulcrum, allowing the directional force provided by the elevator muscles to seat the condyles in a superior position within the fossae. The technique can be coupled with the bilateral mandibular manipulation technique.
In this technique, the mandible is closed, the lower incisors strikes against a stop that is precisely fitted against the upper incisors. The stop should be thin enough so that the first point of tooth contact barely misses but under no circumstances should any posterior tooth be allowed to contact when the anterior stop is in place. A firm setting bite registration paste is injected between the posterior teeth and allowed to set. ,,,
Various anterior deprogrammer devices are as follows: 
- Cotton rolls
- Plastic leaf gauge
- Auto polymerizing resin
- Lucia jig.
The enamel island (cone) method
This method preserves a centric stop on an abutment as an aid when making interocclusal record. It is generally used in cases where posterior abutment is the distal most tooth of the arch.
Cone preparation on a natural abutment
Prepare the abutment leaving a slightly tapered or a wide island (cone). The cone is removed from the cast during fabrication of prosthesis and from the abutment during cementation. ,
| Interocclusal Recording Material in Carrier|| |
Interocclusal recording materials can be loaded in a carrier, that is, bite registration tray. The frame is tried in the mouth on the side with the prepared teeth. Trim away the film that covered the unprepared teeth. Apply the bite registration material evenly on to both top and bottom of the frame and insert the tray in the mouth, centering the loaded portion over the prepared tooth or teeth. Cut of any material that extends over the unprepared teeth adjacent to preparation. Remove the excess thickness of the record so that only the imprint of cusp tip should remain. The part of the record facial to the mandibular buccal cusp tips is cut off all the way through the posterior member of the frame and the facial segment of the record is discarded. ,,
| Interocclusal Registration for Fixed Implant-supported Prosthesis|| |
Make an impression with a custom tray and elastomeric impression material. Insert the provisional restoration. Place the impression coping. Remove any part of impression copings that interferes with complete closure in the maximum intercuspation position with a sharp scalpel. Make the interocclusal record with a putty-type vinyl polysiloxane impression material. Place the impression copings and interocclusal record over the shoulder of implant analogue on the definitive cast. Mount the mandibular cast in an articulator with the aid of the interocclusal record. Evaluate the fit and occlusion of definitive restoration, and lute the definitive restoration. ,
| Discussion|| |
Stable and accurate interocclusal records can be made in clinical situations using several techniques and materials.
Construction of a prosthetic restoration involves many steps and it is important to understand that incorporation of error can occur at any step. However, a major source of error is while taking the registration records and transferring them to the articulator. These errors can be minimized by proper selection of the materials and technique used, by knowledgeable application of the properties and the various shortcomings of the interocclusal recording mediums and the technique used to record the relationship.
Despite the opinion of several investigators like Millstein in 1989, Shrunik in 1977, Fattore in 1984 that wax is an unfavorable material for interocclusal registration, it is the most utilized material in the dental practice due to its ease of handling, clinical versatility, ease of corrections and low cost. Combinations of wax with rigid materials like Zinc oxide eugenol paste and acrylic resin have also been used as they incorporate less error. However, these have their own drawbacks. The major problem with Zinc oxide eugenol paste is that it is a brittle material that tends to adhere to the teeth and when used in excess, it may distort. Acrylic resin provides more security to the operator at the time of seating the casts on the registrations as justified by studies performed by Stamoulis in 2009 and Anselm Wiskott H W et al. in 1989. Elastomeric impression materials are among the preferred materials as per the various investigations conducted over their accuracy and dimensional stability. However, their major setback is the affordability. ,,,
The most widely used technique is wax bite record as suggested by Dawson. Anterior stop method deprograms the muscles and helps to achieve correct centric relation. The triple tray technique maintains the interocclusal distance accurately, but requires a special tray for the procedure. In the enamel island (cone) method by Sato et al. in 2000 a conical vertical stop is used as a third point of reference to make a stable occlusal relationship. But if the cone is slender it may result in instability of the vertical stop when it contacts the oblique plane. The wide enamel cone can provide better stability, but may result in inaccuracy of the prepared occlusal surface, because a large volume of enamel has to be removed later. ,,,
| Conclusion|| |
To properly evaluate a patient's occlusion and to build up an artificial dynamic occlusal scheme, it is mandatory that the diagnostic casts and the final casts are placed in an articulator in approximately the same relationship to the temporomandibular joint as it exists in the patient. The ideal material-technique combination for making interocclusal records would allow the placement of indirectly fabricated prostheses in the patient's mouth with no occlusal adjustment and hence play a major role in the success of the rehabilitative procedures in terms of function and esthetics.
| References|| |
|1.||The glossary of prosthodontic terms. J Prosthet Dent 2005;94:10-92. |
|2.||Warren K, Capp N. A review of principles and techniques for making interocclusal records for mounting working casts. Int J Prosthodont 1990;3:341-8. |
|3.||Freilich MA, Altieri JV, Wahle JJ. Principles for selecting interocclusal records for articulation of dentate and partially dentate casts. J Prosthet Dent 1992;68:361-7. |
|4.||Malone WFP, Koth DL. Tylman's Theory and Practice of Fixed Prosthodontics.8 th ed. Ishiyaku EuroAmerica, Inc. Publishers. Tokyo. St. Louis. |
|5.||Squier RS. Jaw relation records for fixed prosthodontics. Dent Clin North Am 2004;48:vii, 471-86. |
|6.||Skurnik H. Resin registration for interocclusal records. J Prosthet Dent 1977;37:164-72. |
|7.||Millstein PL, Clark RE. Differential accuracy of silicone-body and self-curing resin interocclusal records and associated weight loss. J Prosthet Dent 1981;46:380-4. |
|8.||Millstein PL, Clark RE, Kronman JH. Determination of the accuracy of wax interocclusal registrations. II. J Prosthet Dent 1973;29:40-5. |
|9.||Fattore L, Malone WF, Sandrik JL, Mazur B, Hart T. Clinical evaluation of the accuracy of interocclusal recording materials. J Prosthet Dent 1984;51:152-7. |
|10.||Millstein PL. Accuracy of laminated wax interocclusal wafers. J Prosthet Dent 1985;54:574-7. |
|11.||Millstein PL, Hsu CC. Differential accuracy of elastomeric recording materials and associated weight change. J Prosthet Dent 1994;71:400-3. |
|12.||Millstein PL, Clark RE, Myerson RL. Differential accuracy of silicone-body interocclusal records and associated weight loss due to volatiles. J Prosthet Dent 1975;33:649-54. |
|13.||Baraban DJ. Establishing centric relation and vertical dimension in occlusal rehabilitation. J Prosthet Dent 1962;12:1157-65. |
|14.||Lassila V, McCabe JF. Properties of interocclusal registration materials. J Prosthet Dent 1985;53:100-4. |
|15.||Pagnano Vde O, Bezzon OL, de Mattos Mda G, Ribeiro RF, Turbino ML. Clinical evaluation of interocclusal recording materials in bilateral free end cases. Braz Dent J 2005;16:140-4. |
|16.||Stamoulis K, Hatzikyriakos AE. A technique to obtain stable centric occlusion records using impression plaster. J Prosthodont 2007;16:406-8. |
|17.||Stamoulis K. Intraoral acrylic resin coping fabrication for making interocclusal records. J Prosthodont 2009;18:184-7. |
|18.||Anselm Wiskott HW, Nicholls JI. Fixed prosthodontics centric relation registration technique using resin copings. Int J Prosthodont 1989;2:447-52. |
|19.||Lassila V. Comparison of five interocclusal recording materials. J Prosthet Dent 1986;55:215-8. |
|20.||Dawson PE. Functional occlusion: from TMJ to smile design.1 st ed. St. Louis CV Mosby (Elsevier) 2007. p. 93-7. |
|21.||Rosensteil, Land, Fujimoto. Contemporary fixed Prosthodontics. 4 th ed. St.Louis Mosby (Elsevier) 2001. p. 40-100. |
|22.||Sato Y, Hosokawa R, Tsuga K, Kubo T. Creating a vertical stop for interocclusal records. J Prosthet Dent 2000;83:582-5. |
|23.||Sonune S, Dange S, Khalikar A. An accurate interocclusal record by creating a vertical stop. J Indian Prosthodont Soc 2005;5:119-23. |
|24.||Petridis HP. Stable interocclusal records for implant patients with posterior edentulism. J Prosthet Dent 2004;92:503. |
|25.||Savabi O, Nejatidanesh F. Interocclusal record for fixed implant-supported prosthesis. J Prosthet Dent 2004;92:602-3. |
|26.||Singh L, Giri P, Meena G, Sharma D. Significance of interocclusal records for fixed prosthodontics: A review of different techniques. J Oral Health Res 2011;2:66-70. |