Relationships among Bone Quality, Implant Osseointegration, and Wnt Signaling

Abstract

A variety of clinical classification schemes have been proposed as a means to identify sites in the oral cavity where implant osseointegration is likely to be successful. Most schemes are based on structural characteristics of the bone, for example, the relative proportion of densely compact, homogenous (type I) bone versus more trabeculated, cancellous (type III) bone. None of these schemes, however, consider potential biological characteristics of the bone. Here, we employed multiscale analyses to identify and characterize type I and type III bones in murine jaws. We then combined these analytical tools with in vivo models of osteotomy healing and implant osseointegration to determine if one type of bone healed faster and supported osseointegration better than another. Collectively, these studies revealed a strong positive correlation between bone remodeling rates, mitotic activity, and osteotomy site healing in type III bone and high endogenous Wnt signaling. This positive correlation was strengthened by observations showing that the osteoid matrix that is responsible for implant osseointegration originates from Wnt-responsive cells and their progeny. The potential application of this knowledge to clinical practice is discussed, along with a theory unifying the role that biology and mechanics play in implant osseointegration.

Retrospective radiographic observational study of 1692 Straumann tissue‐level dental implants over 10 years: I. Implant survival and loss pattern

“…Based on one study, 26 19,28,29 However, in contrast to this study, the results from those studies were based on products from different companies. The probability of failure was significantly higher in the mandibular anterior area than in the other sites.…”

“…The probability of failure was significantly higher in the mandibular anterior area than in the other sites. Based on one study, 26 being a risk factor. Many authors have reported that the probability of implant failure is highest for maxillary anterior teeth.…”

Biophysical regulation of osteotomy healing: An animal study

“…We located the sites where osteoprogenitor cells resided. Type III bone is penetrated by vascular sinusoids (Figure I) and co‐immunostaining with DAPI, Osterix, and beta galactosidase to identify Wnt responsive cells identified this as the primary location for this osteoprogenitor cell population (Figure J). By POD7, these Runx2 +ve and Osterix +ve cells had contributed to the faster healing observed in Type III bone osteotomies (Figure K‐M).…”

“…In previous studies, we demonstrated that the murine maxillary edentulous ridge represents dense, lamellar Type I bone and a healed maxillary M1 extraction site represents trabecular Type III bone. 27 Therefore, using a constant drill speed, we tested whether osteotomy healing differed between these two Types of bone.…”

Wedge-Shaped Implants for Minimally Invasive Treatment of Narrow Ridges: A Multicenter Prospective Cohort Study

“…This slow increase in secondary stability could be explained by the fact that implants were inserted in atrophic ridges (mean bone width 3.8 mm), with most of the implant surface facing only buccal and lingual cortical bone. Recent histomorphometric and biomolecular studies clearly demonstrated that new bone formation starts primarily in the spongious bone and that the rate of new bone formation is significantly increased in trabeculated cancellous bone osteotomies compared to equivalent osteotomies in densely compact cortical bone [ 36 ]. These considerations could explain why, in the present study, ISQ values at T2 resulted significantly higher in maxilla than in mandible and suggest that the healing period after wedge implant placement in narrow ridges could be slightly longer than that of a standard implant inserted in a bone crest with a good quantity of spongious bone.…”