Effect of grafting materials on osseointegration of dental implants surrounded by circumferential bone defects An experimental study in the dog Faleh Abushahba Stefan Renvert Ioannis Polyzois Noel Claffey Authors’ affiliations: Faleh Abushahba, Ioannis Polyzois, Noel Claffey, School of Dental Science, Trinity College, Dublin, Ireland Stefan Renvert, Department of Health Sciences, Kristianstad University, Kristianstad, Sweden Correspondence to: Prof. Noel Claffey School of Dental Science Trinity College Dublin 2 Ireland Tel.: þ 353 1 6127 306 Fax: þ 353 1 6711 255 e-mail: nclaffey@dental.tcd.ie Key words: extraction socket, immediate implant, osseointegration Abstract Aims: This study was designed to evaluate the effect of gap width and graft placement on bone healing around implants placed into simulated extraction sockets in the mandibles of four beagle dogs. Materials and methods: Four Ti-Unite s implants (13 mm  3.3 mm) were placed on each side of the mandible. Three implants were surrounded by a 1.35 mm circumferential and a 5 mm deep gap around the coronal portion of the implants. A fourth implant was inserted conventionally into both sides of the mandibles as a positive control. The gaps were filled with either Bio-Oss s , autogenous bone or with a blood clot alone. The study design was balanced for animal, side and modality. Ground sections were prepared from biopsies taken at 3 months, and computer-aided histometric measurements of bone/implant contact and area of bone within threads were made for the coronal 5 mm. Data were analysed using analysis of variance. Results: The mean bone/implant contact was 9.8 mm for the control and ranged from 9.3 to 11.3 mm for the three test modalities. The corresponding values for area within threads were 1 mm 2 and 1–1.2 mm 2 . Modality had a significant effect on both bone/implant contact (F ¼ 16.9; Po0.0001) and area within threads (F ¼ 16.7; Po0.0001). Conclusion: The results of this study suggest that both autogenous bone graft and Bio-Oss s played an important role in the amount of hard tissue fill and osseointegration occurring within marginal bone defects around implants. Immediate placement of implants into fresh extraction sockets has the potential of decreasing the total treatment time for patients (Gotfredsen et al. 1993; Kohal et al. 1997; Brunel et al. 1998). Another advantage with immediate implant place- ment is that the extraction socket may serve as a guide for optimal positioning of the implant (Gotfredsen et al. 1993; Brunel et al. 1998). Furthermore, bone resorption normally associated with socket healing may be minimised when implants are placed immediately after extraction (Gotfredsen et al. 1993; Becker et al. 1994, 1998; Rosenquist & Grenthe 1996; Paolantonio et al. 2001) although recently released studies claim that their placement does not have such an effect (Arau ´ jo et al. 2005; Botticelli et al. 2005). When implants are placed at the time of tooth extraction, there is often a gap between the walls of the extraction socket and the implant. This gap is usually widest in the coronal aspect of the socket (Akimoto et al. 1999). Findings from clinical studies and case report series indi- cated that the installation of implant into fresh extraction sites may allow for osseoin- tegration and long-term implant survival Date: Accepted 29 January 2007 To cite this article: Abushahba F, Renvert S, Polyzois I, Claffey N. Effect of grafting materials on osseointegration of dental implants surrounded by circumferential bone defects. An experimental study in the dog. Clin. Oral Impl. Res. 19, 2008; 329–334 doi: 10.1111/j.1600-0501.2007.01455.x c  2008 The Authors. Journal compilation c  2008 Blackwell Munksgaard 329