The tenacious hyperglycemia in diabetic people, hinder osteoblastic activity and modifies the response of parathyroid hormone that adjusts metabolism of Ca and P, decreases collagen synthesis during callus formation, induces apoptosis in lining cells of bone and increases osteoclastic activity due to untiring inflammatory response. It also stimulates deleterious effect on bone matrix and reduces growth and buildup of extracellular matrix. The subsequent result is reduced bone formation during healing.
Type -1 diabetes (insulin dependent) causes decreased bone formation, as well as reduced bone mineral density and higher bone resorption while Type -2 diabetes (non-insulin dependent) produces normal or greater bone mineral density in some patients. It has been detected that insulin not only diminishes the harmful effect of hyperglycemia by controlling it but also stimulates osteoblastic activity.
Success/failure of dental implants in diabetic patients
Most of the studies detected slightly high percentage of early failure of implants in diabetics compared to late failure. Some reports indicated increased failure rate within first year of loading signifying the risk of implant failure is associated with uncovering of implants and early stage of implant loading. The study conducted by T W Oates also supports high early failure in diabetic patients as such patients had low implant stability quotient (ISQ) in a time span of 2-12 weeks. It was also noted that, lower the level of glycemic control, higher the amount of ISQ reduction and longer the length of recovery in ISQ at base level was required. Nevertheless, most of implants attained base level of stability within 4 months even in uncontrolled diabetic patients, if the patients were refrained with micro- and macro-vascular complications.
It was observed in one study that the duration of diabetes significantly affected the success of dental implant. While another study did not demonstrate significantly higher late implant failures in diabetic patients even with longer duration.
Overall lower success of implant in patients with diabetes of extended duration may be due to increased chance of micro-vascular complications that consequently lead to deferred healing around implants and hence higher early failure.
Few studies, demonstrated significantly higher failure of implant in type-1 diabetic patients than patients with type-2 diabetes. It may be due to depletion of insulin in tissues whereas presence of insulin in tissues of type-2 diabetic individuals may reduce deleterious effect of hyperglycemia.
Immediate loading did not significantly affect the existence of dental implant in diabetic patients provided their plasma glucose level were under normal range. Balshi SF conveyed 100% survival of 18 implants after 2.5 years after placement followed by immediate loading with screwed retained fixed prosthesis in a 71-year-old diabetic patient. The study proposes that measured mechanical stimuli over implant can be advantageous for osseointegration and implant survival.
Techniques for improving success of dental implant in diabetic patients
Preoperative and post-operative, good glycemic control is mandatory to achieve improved osseointegration in diabetics. Prophylactic antibiotics have shown to be effective for success of dental implants in diabetic patients. Use of 0. 12% chlorhexidine further improves the success rate.
Few factors like implant surface characteristics (implant coated with bioactive material) and increased implant length and width has been shown to increase success rate of implant in diabetic patients.
The survival of dental implant in fairly controlled diabetic patients looks as good as in overall population. Use of prophylactic antibiotic, longer duration of post-surgical antibiotic course, chlorhexidine mouth rinse, implants coated with bioactive material and implant with increased width and length appears to further improve the survival of implant in diabetic individuals.
Rajendra Kumar Dubey, Deepesh Kumar Gupta, and Amit Kumar Singh Natl J Maxillofac Surg. 2013 Jul-Dec; 4(2): 142–150.