Discussion

This article demonstrated that implant placement was successful after vitamin D supplementation in patients with vitamin D deficiency and early failed implants. None of the patients showed systemic disease or did take regular medication, alcohol, nicotine, or drugs. The patients were not immunosuppressed, irradiated, or received chemotherapy. All implants were inserted with the same recommended torque of <35 Ncm. Bone overheat or compression due to implant preparation/placement or contamination of implants surface during the surgical procedure were excluded due to a sufficient irrigation and the surgical protocol. In the end, only common obvious deficit of both patients was vitamin D deficiency. The blood analysis was otherwise unsuspicious. However, in the first patient, implants were placed 3 months after vertical autogenous bone augmentation with no systemic antibiotic treatment while antibiotics were given during the third successful attempt several months after guided bone regeneration. Missing antibiotic treatment and the grafting procedures have to be considered as conceivable factors for the early implant failure in the present patients nonetheless. To date, a vitamin D screening before implant placement has not become standard in our clinic; but in patients with early implant failure, a vitamin D screening is initiated.

Local and systemic factors can affect the survival rate of dental implants. The causes of early implant failure are not fully clarified and an association between vitamin D and dental implant osseointegration has not been investigated properly. Some recent animal studies in rodents demonstrated a relationship between vitamin D supplementation and an increased bone to implant contact/volume after implant placement. Mengatto et al. demonstrated an impaired osseointegration in vitamin D-deficient rats. Other authors cannot confirm an effect of vitamin D supplementation on bone formation around titanium implants in diabetic rats. A combination of local or systemic calcium supplementation and vitamin D seems to influence bone regeneration in extraction sockets of the dog as it demonstrates significantly higher bone formation and bone density and significantly less vertical ridge reduction in contrast to sockets without supplementation