Periodontitis is one of the major causes of tooth loss in the world. It encompasses multifactorial diseases involving bacterial biofilms and generation of an inflammatory response including the production of cytokines and matrix metalloproteinases.

For many years, the major focus of periodontal research has been directed towards the reduction or elimination of pathogenic bacteria that are thought to cause periodontitis. This has been accomplished in a large part by the use of mechanical treatment approaches like scaling and root planning, use of home care measures and finally surgical intervention. In recent years, other adjunctive approaches that aim to eradicate or reduce the periodontal disease initiation or progression have included pharmacologic measures with the use of systemic and/or local anti-microbial therapies.

Even when periodontal diseases are controlled or cured, the patients are often left with an anatomical evidence of the disease, including loss of bone and periodontal support for their remaining teeth. Therefore, newer approaches are being developed to stimulate regeneration of lost periodontal tissues.

Apart from periodontal therapy directed towards regeneration, it appears that most treatments available today are directed towards reduction or elimination of exogenous factors that might cause or exacerbate periodontal diseases. There is still an increasing body of evidence suggesting that various approaches which involve host modulation might also be helpful in the management of periodontitis and its sequelae.

Three potential approaches to host modulation therapy have been considered: 1) inhibition of matrix metalloproteinases with antiproteinases,e.g. tetracyclines. 2) blocking production of pro-inflammatory cytokines and prostaglandins with anti-inflammatory drugs, e.g. NSAIDs: aspirin, ibuprofen, naproxen.  and 3) inhibiting activation of osteoclasts with bone sparing agents e.g. bisphosphonates: Alendronate.

The bisphosphonates are synthetic biochemical modifiers of bone resorption. The bisphosphonates are widely used in the management of systemic metabolic bone diseases due to their ability to inhibit bone resorption. Given their known affinity to bone, ability to increase osteoblastic differentiation and to inhibit osteoclast recruitment and activity; there exists a possible use for bisphosphonates in the diagnostic and management of periodontal diseases.

Among Bisphosphonates, Alendronate Sodium has been found to be very effective in inhibition of bone resorption.  When given systemically in patients with periodontal disease, Alendronate can significantly reduce alveolar bone resorption and cause an improvement in the height of the crestal bone.

Though the systemic use of bisphosphonates, including etidronate, alendronate, pamidronate and risedronate, can lead to reduced bone turnover, increased bone mass and improved mineralization, studies have shown similar promising results with the local use of bisphosphonates.

Studies have shown that systemically administered bisphosphonates can induce gastrointestinal disturbances such as esophagitis, erosions, and ulcerations. Local drug application avoids most of these problems, by limiting the drug to the target site (site specific approach) with little or no systemic uptake. Also, the local concentration achieved can be much higher (100 folds) than that via systemic route.

Thus, the present study aims to evaluate clinically and radiographically the efficacy of local application of 1% Alendronate Sodium gel as anadjunct to surgical therapy in the treatment of osseous bone defects in patients with chronic periodontitis.