Bone cell attachment to dental implants of different surface characteristics

Aim of the study

To compare the behaviour of osteoblasts on different implant surfaces : smooth (Astra^®), rough (IMZ^®, Astra^®and Straumann^®) or HA coated (IMZ^®).

Materials and methods

Rat neonatal osteoblasts were placed with implants in nylon chambers and bathed in a culture medium for 20 minutes in such a way as to permit total contact between the implant and bone cells.

Four types of cellular contact are described :

1. No intimate contact = rounded cells.

2. Little contact = cells with few pseudopodia.

3. Contact = cells elongated with pseudopodia.

4. Intimate contact = flattened cells with extended pseudopodia.

Conclusion

In the case of smooth implants (Astra^®), roughened Ti-02 type (Astra ^®) or HA coated (IMZ^®), the cellular attachment was usually of the first type.

For roughened plasma sprayed titanium implants (IMZ^® and Strauman^®) the four types of attachment occurred in equal numbers.

The type 4 attachment with the most intimate cellular adaptation occurred more with plasma sprayed implants than with the others.

Commentary

These results confirm those of other studies (Brunette, 1988 ; Bizios, 1994) to show that cells have a greater affinity for rough surfaces than for smooth surfaces. However, it must not be forgotten that these are short term results and that in the longer term, these differences disappear. Moreover, in this study, the authors recognise that the same number of cells attached to the 5 implant surfaces and it was only the type of attachment that differed.

Finally, this study has the merit of suggesting a very elegant protocol (nylon chambers) that will surely be repeated for other similar studies.