Endosseous dental implants are available with various surface characteristi
cs ranging from relatively smooth machined surfaces to more roughened surfa
ces created by coatings, blasting by various substances, by acid treatments
, or by combinations of the treatments. Studies characterizing these implan
ts and surfaces include in vitro experimentation, animal studies, and human
clinical trials. Both descriptive and functional testing of the bone-impla
nt interface includes histomorphometrics and biomechanical testing such as
torque removal values and push out/pull out strength. Using these assays to
evaluate and compare different surfaces, the data demonstrate that rough i
mplant surfaces have increased bone-to-implant contact and require greater
forces to break the bone-implant interface compared to more smooth surfaces
. The objective of this report was to evaluate publications of human clinic
al experiences evaluating implant use in patients and to determine if diffe
rences existed in success rates of implants with relatively smooth surfaces
compared to implants having roughened implant surfaces. Human trials were
reviewed to determine the clinical efficacy of implants under various clini
cal indications. Synopsis tables were constructed and the experiences segre
gated by implant surface characteristics. Meta-analyses were performed on a
ll implants in all locations, on implants placed only in the maxilla or the
mandible, and, finally, on implants placed in the maxilla compared to impl
ants placed in the mandible. Evaluation of the data revealed that predictab
ly high success rates can be achieved for implants with both rough and smoo
th titanium surfaces and for hydroxyapatite-coated implants. When studies w
ere clustered by specific indications or patient populations, rough surface
d implants had significantly higher success rates compared to implants with
more smooth surfaces except in the case of single tooth replacements where
the success rates were comparable. In general, implants placed in the mand
ible had significantly higher success rates than implants placed in the max
illa. However, in the partially edentulous patient group, titanium implants
with a rough surface had significantly higher success rates in the maxilla
compared to the mandible and, in cases of single tooth replacement, succes
s rates were similar in the maxilla and in the mandible as was the case for
hydroxyapatite-coated implants. The documented advantage of implants with
a roughened surface in animal and in vitro experiments has been demonstrate
d in clinical cases when studies were compared in which specific indication
s or patients were treated. Additionally, implants placed in the mandible h
ave, in general, higher success rates than implants placed in the maxilla,
with only a few exceptions noted. These data from human clinical experience
s support the documented advantage of implants with a roughened surface in
animal and in vitro experimentation and indicate that the magnitude of the
advantage is significant for patient care.