Determination of the Dynamics of Healing at the Tissue-Implant Interface by Means of Microcomputed Tomography and Functional Apparent Moduli

Abstract

Purpose It is currently a challenge to determine the biomechanical properties of the hard tissue–dental implant interface. Recent advances in intraoral imaging and tomographic methods, such as microcomputed tomography (micro-CT), provide three-dimensional details, offering significant potential to evaluate the bone-implant interface, but yield limited information regarding osseointegration because of physical scattering effects emanating from metallic implant surfaces. In the present study, it was hypothesized that functional apparent moduli (FAM), generated from functional incorporation of the peri-implant structure, would eliminate the radiographic artifact–affected layer and serve as a feasible means to evaluate the biomechanical dynamics of tissue-implant integration in vivo. Materials and Methods Cylindric titanium mini-implants were placed in osteotomies and osteotomies with defects in rodent maxillae. The layers affected by radiographic artifacts were identified, and the pattern of tissue-implant integration was evaluated from histology and micro-CT images over a 21-day observation period. Analyses of structural information, FAM, and the relationship between FAM and interfacial stiffness (IS) were done before and after eliminating artifacts. Results Physical artifacts were present within a zone of about 100 to 150 μm around the implant in both experimental defect situations (osteotomy alone and osteotomy + defect). All correlations were evaluated before and after eliminating the artifact-affected layers, most notably during the maturation period of osseointegration. A strong correlation existed between functional bone apparent modulus and IS within 300 μm at the osteotomy defects (r > 0.9) and functional composite tissue apparent modulus in the osteotomy defects (r > 0.75). Conclusion Micro-CT imaging and FAM were of value in measuring the temporal process of tissue-implant integration in vivo. This approach will be useful to complement imaging technologies for longitudinal monitoring of osseointegration.

Comparative Evaluation of Bone Repair with Four Different Bone Substitutes in Critical Size Defects

“…In the first period, there was intense osteoblastic activity, observed through immunohistochemical analysis, which resulted in greater bone formation on the last assessed period, with almost total closure of critical bone defects. In the speculation about clinical applicability, maturation of bone tissue, an important factor for primary stability in the installation of dental implants [26,27] demonstrated through immunohistochemistry, increased osteocalcin expression for the CLN group at 40 days compared to 14 days.…”

Sclerostin-Neutralizing Antibody Enhances Bone Regeneration Around Oral Implants

“…27,28 While we did not perform specific biomechanical testing in this study, we noted that BIC, BVF, TMD, and BMD have strong and moderately strong correlation with the functional apparent modulus, which indicates that histology and microCT data are parallel with mechanical test data, as we have previously reported. 27,30,31 Based on this model, we chose the experimental approach and time points of 10, 14, and 28 days to study effects of the sclerostin antibody on bone formation and dental implant osseointegration.…”

A comparison of micro-CT and histomorphometry for evaluation of osseointegration of PEO-coated titanium implants in a rat model

“…However, micro-CT has several drawbacks. First, artifacts around the metal implant decrease the accuracy of micro-CT results 23 , 24 . Schouten et al .…”

“…Many studies have shown the potential of this method for evaluating osseointegration 3 , 12 – 22 . However, the accuracy of micro-CT-based quantitative evaluation may be affected by unavoidable metal scatter surrounding the titanium implant due to the implant material 23 , 24 .…”