Tactile misfit detection ability at the implant-abutment interface of internal connection dental implants: an in-vitro study

Abstract

Objective

The aim of this in-vitro study was to investigate the tactile assessment ability at the implant impression-taking stage.

Methods

Thirty clinicians (18 novices, 12 experts) were included for a tactile fit assessment by using a used/new probe (tip diameter 100 µm/20 µm). Six implant replicas and related impression copings of two internal connection implant systems were used, each with a perfect fit (0 µm) and defined vertical micro gaps of 8, 24, 55, 110 and 220 µm at the interface. Statistical analysis was performed using descriptive methods and non-parametric tests with a focus on specificity (ability to detect perfect fit), sensitivity (ability to detect misfit), and predictive values. P-values <5% were considered statistically significant.

Results

The tactile assessment showed a mean total sensitivity for the Straumann and Nobel Biocare systems of 83% and 80% with a used probe, and 91% and 92% with a new probe, respectively. The mean total specificities were 33% and 20% with a used probe and 17% and 3% with a new probe, respectively. No statistical significance was observed between novice and expert clinicians concerning their tactile assessment ability.

Conclusions

The ability to detect a perfect fit (specificity) with a probe was very poor for both implant systems and impaired with the use of a new probe. The use of a new probe improved the gap detection ability (sensitivity) significantly at the expense of the specificity. A combination of additional chairside techniques with training and calibration could improve clinicians’ ability to correctly assess the fit/misfit at the implant-abutment interface.

Keywords:

• Dental implants
• dental implant-abutment design
• implant-abutment interface
• dental abutment connection
• dental impression

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.