Influence of abutment macro‐ and micro‐geometry on morphologic and morphometric features of peri‐implant connective tissue

Abstract

ObjectivesThe aim of the present human observational study is to provide morphologic and morphometric analysis of peri‐implant connective tissue next to abutments with divergent or convergent macro‐geometry and different surface micro‐characteristics.Materials and MethodsThirty patients were rehabilitated with single implants in the posterior area and one out of three different healing abutments with a one‐stage technique: machined divergent abutment (DIV‐MAC), machined convergent abutment (CONV‐MAC) or convergent abutment with ultrathin threaded surface (CONV‐UTM). At 3 months postimplant insertion, peri‐implant soft tissue was harvested; the following outcomes were investigated: histomorphometry (vertical width of connective and epithelial components) as detected by histology and polarized light; and connective tissue vertical width and 3D organization as detected by synchrotron‐based high‐resolution phase‐contrast‐based tomography (PhC‐μCT).ResultsSignificant differences in connective tissue vertical dimension (aJE‐AM) were found between DIV‐MAC and both CONV‐MAC and CONV‐UTM, both by histology and PhC‐μCT, with significantly higher values for the last two groups. Moreover, 2D histological analysis did not find significant differences in the junctional epithelium vertical dimension (PM‐aJE). Importantly, PhC‐μCT analysis revealed, at 3D level, significant greater amount and density of collagen bundles for CONV‐UTM compared with the other two groups.ConclusionsConvergent abutment profiles, regardless of their surface micro‐geometry, seem to favor axial development of peri‐implant connective tissue. Moreover, ultrathin threaded surfaces seem associated with denser and greater connective tissue organization, which might improve peri‐implant soft tissue seal.

Soft tissues and force fields: advanced 3D synchrotron-based imaging for diagnostics and regenerative medicine

“…These observations and exploratory hypotheses were confirmed in Ref. [25]: in this human observational study it was provided morphologic and morphometric analysis of peri-implant connective tissue next to abutments with divergent or convergent macrogeometry and different surface micro-characteristics. Convergent abutment profiles, regardless of their surface microgeometry, were observed to favor axial development of peri-implant connective tissue.…”

Case Report of a Dental Implant with Conometric Abutment–Prosthetic Cap Connection: Advanced High-Resolution Imaging and Peri-Implant Connective Tissue Performance

“…While many authors have reported on the importance of the characteristics of the fixture-abutment interface on the level and loss of peri-implant bone tissue [35], few studies have examined the structure and ultrastructure of human peri-implant soft tissues [7,11,[13][14][15][16]. The 3D networks of collagen bundles that compose the connective portion have been found to be transversely and longitudinally oriented in relation to the dental implant axis.…”

“…The 3D networks of collagen bundles that compose the connective portion have been found to be transversely and longitudinally oriented in relation to the dental implant axis. During the growth of these bundles, they organize themselves into intertwining patterns [13][14][15] with different quantitative distributions depending on time from surgery, environmental conditions, and implant macro-and micro-geometry; these boundary conditions are currently the focus of several studies [7,11,[13][14][15][16].…”

“…Animal models and human studies have described the structure and ultrastructure of peri-implant soft tissues using bi-dimensional imaging methods like histology, scanning electron microscopy, polarized light microscopy [6][7][8][9][10][11], and transmission electron microscopy [12]. However, only advanced 3D imaging through high-resolution tomography (micro-CT) has been able to give evidence and quantify the organization of connective tissue microarchitecture [13][14][15].…”

High-Resolution Phase-Contrast Tomography on Human Collagenous Tissues: A Comprehensive Review

“…It was demonstrated that synchrotron phase-contrast imaging is capable of studying 3D parameters that cannot be analyzed with histologic techniques but are important to define the 3D microarchitecture of the collagen bundles and the 3D structural complexity of connective tissues. Remaining in the same research field, Canullo et al [40] performed an in-depth study on the impact of the implant macroand micro-geometry on peri-implant connective tissues, most likely linked to the contact force at the interfaces between soft tissues and abutment.…”