Effect of diabetes and metabolic control on de novo bone formation following guided bone regeneration

To evaluate histologically and morphometrically the effect of experimental diabetes and metabolic control on de novo bone formation following guided bone regeneration (GBR).

Thirty-five Wistar rats were allocated in three experimental groups: (a) uncontrolled, streptozotocin-induced diabetes (D); (b) insulin-controlled diabetes (CD); (c) healthy (H). A standardised titanium microimplant with sandblasted and acid-etched surface was placed into the inferior border of the mandible bilaterally. On the test site, the microimplant was covered with a titanium reinforced expanded polytetrafluoroethylene membrane securely fixed in the mandible according to the GBR principle. The contralateral site served as control. Following 90 days of healing, undecalcified sections were prepared and planimetric measurements of the per cent vertical height of newly formed bone and the per cent new bone-to-implant contact were performed.

In all experimental groups, at the GBR treated sites, significant neo-osteogenesis was observed. The vertical height of the newly formed bone and per cent bone-to-implant contact were not statistically significantly different among the H (51.3 + or - 7.2% and 50 + or - 6.8%), D (30.5 + or - 13.4% and 35 + or - 16.8%) and CD (41.6 + or - 8.3% and 39.9 + or - 6.5%) groups. However, uncontrolled diabetes was related to higher outcome variability and increased rate of infectious complications. In the control sites, marginal bone loss was observed in the D group, whereas, in the H and CD groups, minimal new bone formation was observed.

Significant de novo bone formation can be achieved via GBR treatment even in the presence of uncontrolled diabetes, although less predictably compared with the healthy status. Insulin-mediated metabolic control may reverse these adverse effects.