Techniques and materials used for bite registration
Text of bite registration for fixed Prosthodontic restoration
Interocclusal Record Prepared by:Botan Barzan Khafaf MSc. Student Supervised by: Raid Fahim Ass.Prof. Hawler Medical University College of dentistry Conservative department
content Definitions. Criteria of choosing material for bite registration. Materials and their properties that used for bite registration. Technique Comparing between some materials in accuracy Conclusion
Centric Relation After Occlusal Vertical dimension is determined and considered normal. Arch to arch relation. Condyles are in the most middle superior position in glenoid fossae. (1) its a jaw position that should be comfortable for the muscles/nerves/etc. of the TMJ . (2) its a jaw position that can be consistently found regardless of the teeth.
Eccentric I.O.R 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 and non arcon semi adjustable articulator. Protrusive interocclusal records also evaluated.
Centric Occlusion Teeth to teeth relation.maximum intercuspation. Occlusal stop centric occlusion No occlusal stop centric relation When the teeth do not offer vertical and horizontal stability between the arches; an interocclusal record is needed to relate the casts.
Classification of tooth-contact patterns Four groups as follows: 1. Cuspid protected occlusion: the contact of canines on the working side. 2. Group function occlusion: contact of canines, premolars, and/or molars, or contacts of premolars and molars on the working side only.
Classification of tooth-contact patterns 3. Full balanced occlusion: tooth contact patterns with group function or cuspid protected occlusion on the working side plus multiple tooth contacts of posterior teeth on the non-working side . 4. Others: occlusal patterns other than those described. Contact of incisor teeth, if any, were included in this classification.(Ogawa ,1998 ; Gupta , 2013)
Hellman described four ways in which teeth contact 1. surface 2. cusp tip and fossa 3. ridge and groove 4. ridge and embrasure. 138types and 90% of the total units actually make exact contact in dentitions with normal occlusion.
Interocclusal Record TMJ Dentition Periodontal tissue
According to Dawson criteria for accuracy in making interocclusal records : The recording material must not cause any movement of teeth or displacement of soft tissues. The recording material must fit casts as accurately as it fits the teeth intra-orally. The accuracy of the jaw relation record should be checked in the mouth and on the casts.
Sensitivity and Reliability Depend on : Thickness . Strength . Elasticity of the recording materials. Oral environment . Clinicians interpretation . (Sharma et al ,2013)
Accuracy of an interocclusal record Influenced by: Material properties. Recording technique. Reliability of the mandibular position influenced by the occlusal contacts . Muscular action. Tissue changes within the joints . (Ghazal M et al, 2008; Michalakis KX et al, 2004)
Methods are used for the evaluation of occlusal relationships: 1- Quantitative method : evaluating occlusal relationships, the sequence and density of the contacts can be differentiated. Quantitative measures for determining occlusal relationships: Photo-occlusion T-Scan system (Sharma et al ,2013)
Methods are used for the evaluation of occlusal relationships. 2- Qualitative method: Density of the contacts according to the darkness of the marks, this is not a precise criterion for evaluation. Wax, articulating paper. foils. Silk strips .ect (Sharma et al ,2013)
Types of Interocclusal Records Basically, there are two main categories of interocclusal registration: Centric interocclusal records Eccentric interocclusal records. (Sharma et al ,2013)
Indications for Interocclusal Records 1-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), 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 . (Saluja B& Mittal D ,2013)
Indications for Interocclusal Records 2-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. 3-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. (Saluja B& Mittal D ,2013)
THE ACCURACY OF TWO METHODS OF OCCLUSAL REGISTRATION INVOLVING TERMINAL ABUTMENTS AN INVIVO STUDY (Deivanai et al, 2013) Articulation I - Pre operative casts Articulation II - Inter occlusal record with centric stop. Articulation III Iner occlusal record without a centric stop. Within the limitations of the present study; a) Presence of Interocclusal records results in an increase in vertical discrepancy. b) Presence of centric stop was found to cause greater discrepancy than without centric stop. Limitations;more number of samples . -techniques to limit control of interocclusal materials to flow over the centric stop.
INTEROCCLUSAL RECORDS IN PROSTHODONTIC REHABILITATIONS (Prasad et al,2012) When the distal most molar is prepared as the abutment for three to five unit posterior FPD. 1-uses conical stops, prepared in the enamel of the abutment or made of composite or a metal core covered with composite, to maintain the vertical dimension of occlusion and to act as the third point of reference for a stable occlusal 8 relationship when occluding a definitive casts. Materials generally used are polyether, silicone or acrylic resin. drawback; ;forces that either displace soft tissue or tilt the denture bases.
When the distal most molar is prepared as the abutment for three to five unit posterior FPD. 2) stabilized baseplate technique for making interocclusal records which provided a means to record centric and eccentric jaw registrations that are stable intraorally and can also be transferred accurately to the working model. drawback; ;forces that either displace soft tissue or tilt the bases.
3) acrylic resin anterior stop to hold the desired vertical dimension of occlusion.procedure for making an interocclusal record without the use of record bases. Base plate Wax then relined by ZOE.
(Ericsson et al ,2002) 7093% of the variation of the positions of the mounted casts Clinical factors and clinical variation influencing the reproducibility of interocclusal recording methods mandibular positions ( 011%) Materials used (0 29%) clinical variation (Remaining %) (intercuspal position (IP) retruded contact position (RCP) two different types of waxes One FPD One RPD One CD record rims vinyl polysiloxanes one irreversible hydrocolloid
Materials Used for Interocclusal Records Limited resistance before setting to avoid displacing the teeth or mandible during closure. Minimal dimensional change It should be easy to manipulate . 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. Over clinically reasonable time periods, they must have solidity to retain the shape and strength when dental casts are articulated.