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Title Ostell Resonance Frequency Analysis Device is Effective for Measuring Primary Implant Stability
Clinical Question For patients getting dental implants, will using a RFA (Resonant Requency Analysis) device be more effective than percussion and radiographic evaluations for measuring the primary stability of the implants?
Clinical Bottom Line As a simple, non-invasive diagnostic device that many clinicians currently use, the RFA device provides a useful measurement to assess osseointegration and communicate with other providers and researchers. It can measure implant stability better than percussion and radiographic evaluations at any appointment. It is best used in sequential appointments to monitor implant stability through time to observe the trend of osseointegration throughout the healing phases. Caution should be used with immediate loaded implants, because a RFA measurement that shows good primary stability can not accurately predict stability or failure in the future. (See Comments on the CAT below)
Best Evidence (you may view more info by clicking on the PubMed ID link)
PubMed ID Author / Year Patient Group Study type
(level of evidence)
#1) 23149504Makary/201218 patients/40 implantsCross sectional survey/Correlation study
Key resultsUsing RFA to measure implant stability can aid in evaluating clinical implant behavior over a period of healing. Initial Torque (IT) and Bone Volume (BV) are the two major parameters that influence the RFA values, known as Implant Stability Quotient (ISQ). The authors showed that there were ISQ values of 82 – 78 for the mandible and ISQ values of 72-71. Also, larger diameter implants (4.7 mm) had a larger ISQ value, 78-77, compared to smaller diameter implants (4.1 mm) with ISQ values of 75-73. Also, the baseline recordings had similar ISQ values to the 6 week postop visit, yet there was an dip at the 3 week postop visit with an average decrease of ISQ value by 1. The author concluded that using BV, IT, and ISQ volumes may indicate primary stability as well as anticipate the degree of osseointegration at 6 weeks.
#2) 22124054Gupta/201149 Articles comparing RFA with other methods of measuring implant stability Systematic Review
Key resultsMeridith et al (1997) showed that RFA is widely used in clinical research to measure implant stability. There is still much debate about its reliability. RFA evaluates implant stability as a function of the stiffness of implant bone interface. Parameters that affect RFA include bone density type and exposed implant height above the alveolar crest. Huang et al. (2002) showed that the highest resonance frequency value 36.1 kHz was found in type I bone, while resonance frequency of 9.9 kHz was found in type IV bone. RFA could serve as a non-invasive diagnostic tool, but there is currently no threshold range for implant stability, particularly for different implant systems.
#3) 22720282Atieh/201230 studies out of 404 pooledSystematic Review
Key resultsClinically, RFA can be used to monitor implant stability through time, thus used to measure osseointegration through the healing phase. The mean ISQ values were 79.5 at time of surgery, 73.49 at 8 weeks postop, and 79.71 at 1 year postop. Repeated measurements can be used to predict early failure. 6 of the 7 failed implants showed ISQ values of around 50 at the 8 week postop. However, in regards to immediate loaded implants, a baseline measurement of RFA is insufficient to accurately predict osseointegration nor predict failure of the loaded implants, since all 6 of those implants had initial values of 78 or greater.
Evidence Search Resonance frequency Analysis, dental implants
Comments on
The Evidence
Validity: There is some controversy in the reliability of the RFA as a diagnostic tool. It seems to be a good measurement when used repeatedly over time to monitor trends of osseointegration. However, a single point of time such as a baseline measurement at time of implant placement, should not be used to predict future stability. Perspective: It is an important measurement, particularly for clinical researchers. Compared to the other methods such as percussion test, mobility test with the mirror handle, and radiographic analysis, it has much better reliability and a quantitative measurement. This non-invasive, simple to use device can be used clinically as an adjunct to the few other methods of measuring implant stability.
Applicability There is no contraindications for using the device. Perhaps, the one caveat is to not rely on any single measurement in time. It is best used to monitor trends through time, rather than to predict stability from just the baseline measurement. When the trend shows decreasing ISQ values throughout several weeks, early implant failure can be predicted (Glauser, 2004). It is best used in conjunction with the other methods of measuring implant stability. Since no threshold has been established, the device should only be used as an estimate for osseointegration rather than be used for precise cutoff values.
Specialty/Discipline (General Dentistry) (Oral Surgery) (Periodontics) (Prosthodontics) (Restorative Dentistry)
Keywords Resonance Frequency Analysis, Implants, RFA
ID# 2527
Date of submission: 08/29/2013spacer
E-mail vincentlieuho@gmail.com
Author Vincent Ho
Co-author(s) e-mail
Faculty mentor/Co-author Chris Walker, DDS
Faculty mentor/Co-author e-mail WalkerCJ@uthscsa.edu
Basic Science Rationale
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Comments and Evidence-Based Updates on the CAT
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by Robert Lemke, DDS, MD (San Antonio, TX) on 02/25/2014
This is a good review, but does not address clinical practicality. In order to use the Ostell, multiple readings are recommended by placing the "tuning fork" type of post on the implant and taking a measurement. This is a nice objective technique, but not practical in a clinical setting. The simple tapping of an implant with the back of a mirror handle works just as well: high pitch = good integration, low pitch = lack of integration. Not only is this easier, cheaper but also faster.

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