Biomedical Engineering Reference
In-Depth Information
oxide surface layer (Brunette et al., 2001; Faria et al., 2008; Lemons, 2004; Park et al., 2008;
Steinmann, 1998; Williams, 1981).
Ideally, a successful orthopedic or dental implant should have a long-term skeletal
fixation with the host bone (see reviews by Albrektsson and Wenneberg, 2004; Coelho
et al., 2009; Stevens et al., 2008) and be free of later complications, especially microbial
infection (Garvin and Hannsen, 1995; Mombelli, 1997; Zimmerli et al., 2004). A consider-
able number of investigations have focused on modifying the implant surface, especially
dental implants, to enhance bone contact or bone anchorage, defined as osseointegration
(Albrektsson and Wenneberg, 2004; Coelho et al., 2009; Narayanan et al., 2008; Stevens et
al., 2008). Fewer studies, especially on dental implants, have focused on implant surface
treatments that would prevent bacterial adhesion, growth, and colonization (Das et al.,
2008; Shi et al., 2008; Tabanella et al., 2009; Zhao et al., 2009). Even fewer studies have
addressed both osseointegration and antibacterial property in the same implant.
The term “osseointegration” was originally introduced by Brannemark (1969, 1977) to
describe “a close implant-bone contact at the light microscopic level.” However, at the
electron microscopic level, nonmineralized fibrous interface is observed between the cpTi
or Ti alloy and the host bone (Daculsi et al., 1995) as shown in Figure 7.1. Such fibrous tissue
interface is a weak one and when subjected to micromotion may lead to implant loosening
and eventual implant failure. To enhance osseointegration, several surface modifications
have been developed especially for dental implants (Albrektsson and Wenneberg, 2004;
Coelho et al., 2009; Narayanan et al., 2008; Stevens et al., 2008). These modifications can
be classified into two general categories: (1) surface treatments to modify topography and
(2) deposition of bioactive surface coatings, such as by deposition of calcium phosphate
coatings (Figure 7.1).
Ti
FIGURE 7.1
SEM image showing a gap (occupied by fibrous tissue) between Ti alloy implant surface and host bone indicat-
ing absence of true osseointegration. (From Daculsi et al.,
Scan. Microsc.
, 4, 309-314, 1995. With permission.)
