Influence of loading forces on the vertical accuracy of interocclusal records.
OBJECTIVE
To evaluate the influence of loading forces on the vertical discrepancies caused by interocclusal recording materials.


METHODS
A custom-made apparatus was used to simulate the maxilla and mandible. Eight interocclusal records were made in each of the following groups: G1-Aluwax (aluminum wax; Aluwax), G2-Beauty Pink wax (hydrocarbon wax compound; Miltex), G3-Futar D, G4-Futar D Fast, G5-Futar Scan (polyvinyl siloxanes; Kettenbach), and G6-Ramitec (polyether; 3M ESPE). The vertical discrepancies were measured by an inductive displacement transducer connected to a carrier frequency amplifier after storage of the records for 1 hour at room temperature. Different compressive loading forces up to 1 kg were applied onto the upper part of the apparatus to evaluate the influence on the vertical discrepancies of the records. Two-way ANOVA was used for statistical analysis.


RESULTS
The compressive loading force had a statistically significant influence on the vertical discrepancies (P<.01) (ie, higher forces reduced the vertical discrepancies). When a compressive force of 1 kg was applied to the upper part of the apparatus, the mean vertical discrepancies for G1 (11+/-3 microm) and G2 (12+/-3 microm) were statistically significantly higher than in groups G3 (1+/-1 microm), G4 (2+/-1 microm), G5 (0+/-1 microm), and G6 (-2+/-2 microm).


CONCLUSIONS
A compressive force of 1 kg could be used to stabilize the cast during mounting procedures in an articulator using an interocclusal record made of polyvinyl siloxane without vertically changing the interocclusal relationships.
Ghazal
Muhamad
M
Department of Prosthodontics, Propaedeutics, and Dental Materials, School of Dentistry, Christian-Albrechts University at Kiel, Kiel, Germany. mghazal@proth.uni-kiel.de
Kern
Matthias
M
D000704:Analysis of Variance; D019245:Compressive Strength; D003725:Dental Articulators; D003760:Dental Impression Materials; D003799:Dental Stress Analysis; D004987:Ethers; D006801:Humans; D007574:Jaw Relation Record / Q000379:methods*; D003765:Models, Dental; D011145:Polyvinyls; D012833:Siloxanes; D013314:Stress, Mechanical; D014160:Transducers, Pressure; D014716:Vertical Dimension; D014885:Waxes
D003760:Dental Impression Materials; D004987:Ethers; D011145:Polyvinyls; D012833:Siloxanes; D014885:Waxes; C034183:vinyl polysiloxane; C056844:Ramitec