Osseotite s vs. machined surface in poor bone quality A study in dogs Dietmar Weng Marianne Hoffmeyer Markus B. Hu ¨rzeler Ernst-Ju ¨rgen Richter Authors’ affiliations: Dietmar Weng, Ernst-Ju ¨rgen Richter, Department of Prosthodontics, School of Dental Medicine, Julius-Maximilians-University, Wu ¨ rzburg, Germany Dietmar Weng, Marianne Hoffmeyer, Markus B. Hu ¨rzeler, Department of Endodontics and Periodontics, Dental Branch, University of Texas at Houston, TX, USA Markus B. Hu ¨rzeler, Department of Operative Dentistry and Periodontics, School of Dental Medicine, Albert-Ludwigs-University, Freiburg, Germany Private Practice, Munich, Germany Correspondence to: Dr med. dent. Dietmar Weng Department of Prosthodontics School of Dental Medicine Julius-Maximilians-University Pleicherwall 2 97070 Wu ¨ rzburg Germany Tel.: þ 49-931-20173200 Fax: þ 49-931-20173000 e-mail: dietmar.weng@mail.uni-wuerzburg.de Key words: dental implant, bone quality, bone-to-implant contact, Osseotite s surface, machined surface, animal study, histomorphometric study Implant sites with low bone content have exhibited lower implant survival rates than dense bone areas. Alterations of the implant surface seem to influence the bone-to-implant contact rate and may have an impact on implant failure rates in such sites. It was the objective of this animal study to histomorphometrically compare two different implant surfaces in so-called poor bone quality sites. All premolars on one side of the mandible were extracted in five fox hounds. After a healing time of 8 months, four screw-type implants (two with a machined surface (ICE group) and two with a double acid-etched (Osseotite s ) surface (OSS group)) were inserted into the mandible. Upon insertion, the implant apex was located in the ‘hollow’ part of the dog mandible, where the bone content is low. After 4 months healing, histomorphometric evaluations were performed. All implants osseointegrated clinically and histologically. Periapical density measurements revealed similar bone contents in both groups (ICE 49.9±16.7%, OSS 52.2±8.4%; P>0.05). Despite these similar amounts of bone content in the apical area around the implant, the Osseotite s implant surface had a significantly higher bone-to-implant contact rate than the machined surface (OSS 62.9±12.4%, ICE 39.5±13.0%; P<0.01). It is concluded from this animal experiment that, in poor bone quality sites, an implant with an Osseotite s surface can achieve a significantly higher bone-to-implant contact compared to a machined surface. Implant sites with so-called poor bone quality have been associated with lower implant success rates (Friberg et al. 1991; Jaffin & Berman 1991; Truhlar et al. 1994; Jemt & Lekholm 1995). This clinical observation has been presumed to reflect a lower bone content and a lower bone-to- implant contact (BIC) rate due to the highly cancellous structure of these sites (Devlin et al. 1998; Trisi et al. 1999). Clinical recommendations for such areas were to allow for longer healing periods (Adell et al. 1985) so as not to further compromise the long-term implant success rates. Since most of these observations have been made in implants with machined surfaces, questions were raised as to whether alterations in implant surface morphology would increase the BIC in general, and thus clinical success rates, too. Histological studies in animals and humans were indeed able to demonstrate a higher BIC in implants with a roughened surface compared to a machined surface (Buser et al. 1991; Weinla ¨nder et al. 1992; Gotfredsen et al. 1995; Wennerberg et al. 1995; Gottlander et al. 1997; Lazzara et al. 1999; Cordioli et al. 2000; Ivanoff et al. 2001). Moreover, short-term success rates with rough surface implants seem to be higher in areas with low bone content compared to machined-surface implants (Drago 1992; Olsson et al. 1995; Friberg et al. 1997; Sullivan et al. 1997; Cochran 1999; Davarpanah et al. 2001; Testori et al. 2001). Copyright r Blackwell Munksgaard 2003 Date: Accepted 28 November 2002 To cite this article: Weng D, Hoffmeyer M, Hu ¨ rzeler MB, Richter E-J. The Osseotite s vs. machined surface in poor bone quality. A study in dogs. Clin. Oral Impl. Res. 14, 2003; 703–708 703