The biological width around titanium implants. A physiologically formed and stable dimension over time

Aim of the study

The authors assessed changes in sulcus depth (SD), the length of the junctional epithelium (JE) and the connective tissue contact (CTC) over a period of 3 to 15 months after the placement of implants in dogs.

Materials and methods

Sixty-nine implants were placed in six fox hound dogs, divided into 3 groups. The animals in the first group were sacrificed after 3 months, just before loading of the implants in the other two groups. The dogs in the second group were sacrificed at 6 months and those in the third group at 15 months, being 3 and 12 months respectively after implant loading. Non-decalcified histological sections were assessed and subjected to histometric analysis.

Results

There was no significant difference in the dimensions of the biological width (SD + JE + CTC), which was approximately 3 mm in all groups. In the group whose animals had been in function for 12 months, a reduction in SD and an increase in JE were noted. The CTC was reduced in the groups whose implants had been in function.

Conclusion

As is the case for natural teeth, the biological width around implants remains constant, whether or not they are loaded. There are reductions in sulcus depth and in the width of the connective tissue attachment, together with an increase the width of the junctional epithelium, prompted by the loading of the implants.

Commentary

The factors which influence the structural elements of the biological width during healing around implants are illunderstood. Changes could be the result of tissue maturation and/or the result of bringing the implants into function. This study involved exposed implants in animals. It would be interesting to repeat this experiment using buried implants or to vary the size of the « micro-gap » at the implant abutment interface.