Micromotion and dynamic fatigue properties of the dental implant-abutment interface.

Abstract

STATEMENT OF PROBLEM:

Clinical loading may result in micromotion and metal fatigue in apparently stable implant screw joints. This micromotion may contribute to tissue inflammation and prosthesis failure.

PURPOSE:

This study investigated dental implant screw joint micromotion and dynamic fatigue as a function of varied preload torque applied to abutment screws when tested under simulated clinical loading.

MATERIAL AND METHODS:

Fifteen noble alloy single-tooth implant restorations, each containing a hexed UCLA-style gold cylinder, were randomly assigned to 3 preload groups (16, 32, and 48 N.cm). Each group consisted of 5 implants (each 3.75 x 15 mm) and 5 square gold alloy abutment screws. A mechanical testing machine applied a compressive cyclic sine wave load between 20 and 130 N at 6 Hz to a contact point on each implant crown. A liquid metal strain gauge recorded the micromotion of the screw joint interface after 100, 500, 1,000, 5,000, 10,000, 50,000, and 100,000 cycles. Baseline data at 0 N.cm were collected before the application of the specified preload torque.

RESULTS:

The 16 N.cm group exhibited greater micromotion (P<.001) than both the 32 and 48 N.cm groups at all cycle intervals (2-way ANOVA, Tukey HSD). Micromotion of the implant-abutment interface remained constant (P=.99) for each of the preload groups through 105 cycles.

CONCLUSION:

Under the loading parameters of this study, no measurable fatigue of the implant-abutment interface occurred. However, dental implant screw joints tightened to lower preload values exhibited significantly greater micromotion at the implant-abutment interface.

• Authors: D G Gratton, S A Aquilino, C M Stanford
• Journal: The Journal of prosthetic dentistry (J Prosthet Dent) Vol. 85 Issue 1 Pg. 47-52 (Jan 2001) ISSN: 0022-3913 [Print] United States
• PMID: 11174678 (Publication Type: Journal Article)

Chemical References

• Gold Alloys

Topics

• Analysis of Variance
• Dental Abutments
• Dental Implants, Single-Tooth
• Dental Prosthesis Retention (instrumentation)
• Dental Restoration Failure
• Dental Stress Analysis
• Equipment Failure Analysis
• Gold Alloys
• Humans
• Materials Testing
• Motion
• Torque