Variations of CBCT Hounsfield Units at Different Distances from Single-Placed Dental Implant Due to the Metal-Induced Artifact Effect

Abstract

Objective of the research was to assess changes of Hounsfield units as representative values of relative bone density at different distances from single-placed dental implant for quantitative demarcation of beam hardening artifact effect zone. Study sample included 76 pairs of CBCT data sets obtained before and right after single implant placement. Analysis of CBCT images was provided within Planmeca Romexis Viewer software of 5.1.0 version for Windows. Measurements of peri-implant Hounsfield units (HU) were provided by the two approaches: 1) with the use of peri-implant “Verification” instrument within ranges of 1 mm, 2 mm and 3 mm outside the dental implant; 2) by in-detail manual measurement with the use of “Rectangular” instrument from the “Annotation” set within ranges of 1 mm, 2 mm and 3 mm outside the dental implant. Metal artifact effect in means of visually recognizable dark streaking bands (darkening zone) was limited to an average 0.43±0.15 mm around placed dental implants with no statistical difference noted in such installed either at molar or at premolar region (p > 0.05). After implant placement statistically significant increase of Hounsfield values was noted at 1 mm (p < 0.05), 2 mm (p < 0.05) and 3 mm (p < 0.05) outside physically placed implants both at molar and premolar regions compared to the values registered before implant placement outside virtually positioned fixtures. Considering specifics of present study it may be concluded that placement of single dental implant provokes significant variations of CBCT Hounsfield units as representative values of relative bone density through metal artifact effect at distances up to 3 mm from installed fixture.