An in vitro evaluation of resonant frequency analysis to measure fixed bridge stability

Khaled Omer,Deniel Palermo,Callum Youngson,Kathryn Fox,Liam Boyle

doi:10.1038/bdjopen.2015.1

Abstract

Objectives/Aims:To determine whether a clinically available resonance frequency analysis (RFA) device (Osstell Mentor), designed to assess implant integration, could identify a single uncemented retainer on fixed–fixed bridges, in vitro.Materials and Methods:All-metal fixed–fixed bridges were cemented to acrylic tooth analogue abutments with simulated periodontal ligaments. Dental stone bases provided 100 or 50% ‘bone support’ groups (n = 50 in each). Control groups had both retainers cemented, whereas the test groups had the ‘premolar’ uncemented, mimicking clinical failure. A RFA device was used to measure bridge stability, expressed as a modified Implant Stability Quotient (Bridge Stability Quotient—BSQ) from a Smartpeg temporarily affixed to the bridge via composite.Results:The BSQ recorded at the premolar site in both 100 and 50% support models demonstrated highly statistically significant differences (P <0.003) between the control and test groups. Sensitivity and specificity, area under the curve (receiver operating characteristic), analyses showed moderate test accuracy (0.735) for the 100% support group and good accuracy (0.96) for the 50% support group.Conclusion:The investigation suggests that RFA measurements were able to identify, reliably and non-destructively, in vitro, fixed–fixed bridges where the anterior retainer was uncemented. Further clinical research is required to determine whether this technique may allow early diagnosis of failing bridgework.

Highlights

Fixed bridge prostheses are a predictable method to replace a missing tooth or teeth and have been reported to exhibit a10-year survival rate of 72% when placed in the general dental services in the UK.[1]
A standardised, buccal, position of the probe was software analysis allows the resonant frequencies to be recorded as Implant Stability Quotient (ISQ) values from 0 to 100
Investigations have shown satisfactory repeatability of measurements[10] and suggested that implants with a primary stability above ISQ 60–65 may be suitable for immediate loading, whereas implants below ISQ 40 may be more prone to failures.[11]

Summary

Introduction

Fixed bridge prostheses are a predictable method to replace a missing tooth or teeth and have been reported to exhibit a10-year survival rate of 72% when placed in the general dental services in the UK.[1]. Fixed bridge prostheses are a predictable method to replace a missing tooth or teeth and have been reported to exhibit a. Loosening of a retainer in a fixed bridge due to luting cement loss is a common clinical complication of fixed prostheses but may be difficult to determine and diagnose. Retainer failure is a challenging situation especially when luting cements fail under a fixed retainer, whereas another retainer remains cemented.[2] As long ago as 1986, Karlsson[3] reported that 12.6% of patients had undiagnosed loose fixed prostheses retainers and noted that a loose retainer occurs more frequently if the abutment had been root canal treated. Failure of the luting cement and/or loss of retention on one of these retainers may be disguised by the physical retention offered by the other retainer.[4]

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Results

Discussion

Conclusion