IADR Abstract Archives
Extracting Relative Density at Implant-adjacent Sites: Osseodensification versus Conventional Osteotomies
Objectives: Objective: We developed protocols to extract relative density values from 2-D images at implant-adjacent sites; and validated these protocols by comparing density differences between sites prepared using osseodensification and conventional osteotomy burs across three imaging platforms: cone-beam computed tomography (CBCT), 2-D infinite microscopy (IM), and scanning electron microscopy (SEM).
Methods: Methods: Thirty bone-level implants (Hiossen Implants, Englewood, NJ) were placed into human cadaveric bone, 14 using osseodensification (Versah LLC, Jackson, MI) burs and 16 using conventional burs. The implant and surrounding bone were CBCT-scanned, resin-embedded, sectioned, and photographed using an Alicona infinite-focus microscope. SEM photographs were taken for comparison. Density was calculated in derived Hounsfield density units for the CBCT images, and mean gray value for the IM and SEM images at 12 implant-adjacent sites. Density values were standardized against a baseline derived from undisrupted bone to control for natural trabecular variation. Correlation coefficients and ANOVA were used to assess for group differences (α=0.05).
Results: Results: Relative density correlations are moderate-to-high across all 3 imaging platforms (0.63 ≤ r ≥ 0.83). However, IM-derived densities are much closer to SEM-derived densities (µPercentDifference=2.78) than are CBCT-derived densities (µPercentDifference= 45.66). ANOVA showed significant interaction between osteotomy treatment and anatomical region on IM-derived densities (F = 11.618, p-value < 0.01). Mean values for osseodensification sites were consistently higher in maxillary regions, while conventional sites were higher in mandibular sites, confirming our previous research (IADR 2019) on insertion torques.
Conclusions: Conclusions: Relative pixel intensity is an appropriate proxy for bone density. This is significant for lab studies of bone properties in providing reliable density values without radiation or costly software. Our results have broad clinical relevance by showing a positive association between osseodensification bur use and increased density in posterior/maxillary regions, thereby enhancing osseointegration and implant stability. However, more clinical and in vivo studies are needed.
Methods: Methods: Thirty bone-level implants (Hiossen Implants, Englewood, NJ) were placed into human cadaveric bone, 14 using osseodensification (Versah LLC, Jackson, MI) burs and 16 using conventional burs. The implant and surrounding bone were CBCT-scanned, resin-embedded, sectioned, and photographed using an Alicona infinite-focus microscope. SEM photographs were taken for comparison. Density was calculated in derived Hounsfield density units for the CBCT images, and mean gray value for the IM and SEM images at 12 implant-adjacent sites. Density values were standardized against a baseline derived from undisrupted bone to control for natural trabecular variation. Correlation coefficients and ANOVA were used to assess for group differences (α=0.05).
Results: Results: Relative density correlations are moderate-to-high across all 3 imaging platforms (0.63 ≤ r ≥ 0.83). However, IM-derived densities are much closer to SEM-derived densities (µPercentDifference=2.78) than are CBCT-derived densities (µPercentDifference= 45.66). ANOVA showed significant interaction between osteotomy treatment and anatomical region on IM-derived densities (F = 11.618, p-value < 0.01). Mean values for osseodensification sites were consistently higher in maxillary regions, while conventional sites were higher in mandibular sites, confirming our previous research (IADR 2019) on insertion torques.
Conclusions: Conclusions: Relative pixel intensity is an appropriate proxy for bone density. This is significant for lab studies of bone properties in providing reliable density values without radiation or costly software. Our results have broad clinical relevance by showing a positive association between osseodensification bur use and increased density in posterior/maxillary regions, thereby enhancing osseointegration and implant stability. However, more clinical and in vivo studies are needed.