Evaluation of Four Elastomeric Interocclusal Recording Materials

Abstract

Background: The fabrication of dental prosthesis requires the transfer of interocclusal records from patient's mouth to semiadjustable articulators using different kinds of recording media. Any inaccuracy in these interocclusal records leads to occlusal errors in the final prosthesis. This study was conducted to evaluate the dimensional changes occurring in the interocclusal recording material over a given period of time and the material's resistance to compression during the cast mounting on the articulator. Methods: In this in vitro study, the linear dimensional change and compressive resistance of four commercially available elastomeric interocclusal recording media was tested. Three were addition silicones and the fourth was a polyether material. Cylindrical samples of 10mm diameter of each material were prepared in three different thicknesses of 2, 4 and 6mm. Ten samples each of thickness of 2, 4 and 6mm for all four materials were prepared (total of 120 samples). The linear dimensional changes of the samples were evaluated after 24 hours of fabrication. The compressive resistance was measured when each of these was subjected to a constant compressive load of 25 Newtons. Results: The mean linear dimensional change in a horizontal plane was minimum for Kanibite Hard, an addition silicone. Ramitec showed the maximum linear dimensional change. The mean compression distance was least for Futar D Occlusion (an addition silicone) and maximum for Ramitec (a polyether). It was observed that the samples of thickness 2mm for all the materials underwent least compression. Conclusion: The compressive resistance of each elastomer was inversely proportional to the thickness of the sample. This implies that minimum thickness of the recording materials should be used for recording maxillomandibular relations without sacrificing the strength of the interocclusal record. MJAFI 2007; 63 : 237-240

Effect of Immersion and Spray Atomization Technique of Disinfection on Compression Resistance of Two Interocclusal Recording Materials.

“…The deformation may vary with the thickness and the properties of the recording materials used. 4 The testing of the resistance to compression after setting was performed following a modification of the method described in A.D.A specification no 19 for the elastomeric impression materials. 1,15 For standardization, the specimens were stored at room temperature for 24hrs to simulate the time between clinical and laboratory phases.…”

“…2 It has been shown that the compression resistance decreases as the thickness increases. 4 Interocclusal registration materials act as a significant source of cross contamination, so these must be disinfected immediately after their removal from mouth. Occupational safety and health association (OSHA) guidelines in 1996 required dentist, dental laboratory employers and other employers in health care fields to provide protection for their employees against the possibility of infection transmission by implementation of conscientious and consistent barrier controls.…”

Interocclusal recording materials: A review

“…Materials that have been intended for intermaxillary recording procedures include plaster, modeling compound, waxes, acrylic resin, zinc oxide-eugenol pastes, [2] rubber base, and silicone materials. [3] Newer ones include polyether and polyvinyl siloxane for ideal maxillomandibular registration.…”

Comparative Study on Dimensional Stability of Polyvinylsiloxane and Alginate as Interocclusal Recording Materials

“…Maxillomandibular records are necessary to study the status of the dentition and to construct dental restoration. One type of record is used for mounting casts of the teeth or setting the articulator adjustments and another for appraising the degree of occlusal or incisal tooth contacts 2 . Adequate laboratory facilities are commonly not available locally and casts have to be sent to others laboratories for articulation.…”

“…In these situations, the patients' interocclusal records are made and sent along with the cast to the laboratory. This requires that the records must be dimensionally stable for the given period of time before they are used to articulate the casts 2 . Recording maxillomandibular relationship is an important step in oral rehabilitation.…”