Local drug delivery and periodontal regeneration: Are we in a dire strait? An original review

There exists an optimum balance between the microbial population adhering the dental structures and host’s defense mechanisms. However, the continuous admittance of new colonization, break the homeostasis, promoting dysbiosis and generating inflammatory immune responses, leading to structural breakdown of tissues and disease propagation. Periodontal therapy aims at reducing the microbial load and to regenerate the lost periodontium to restore its structure and function, hereby preventing disease reoccurrence. This was achieved by SRP (scaling and root planing) and adjunctive use of antimicrobials. Although presence of dental film is responsible for initiation of periodontal disease, individual’s host susceptibility plays an important role in production of pro inflammatory cytokines, destructive enzymes, MMP’S (matrix metalloproteinases) etc. Thus, host modulating therapy (HMT) in form of various local and systemic host modulating agents have been used as adjunctive therapy. However, certain limitation exists with the systemic delivery of the HMT like first pass metabolism, limited availability at the site, side effects as with bisphosphonates i.e. BRONJ (bisphosphonate related osteoradionecrosis of jaw) and thus local drug delivery of HMT has come up as an advantageous therapy mode in delivering the benefits of antimicrobial, anti- inflammatory and periodontal regenerating host modulating agents. While stage I-III periodontitis can be treated by local drug delivery systems like fibers, strips, gels, nanoparticles etc. Stage IV periodontitis needs true regeneration by help of membranes and scaffolds (stanz et el). But variations in periodontal defect morphology and host response are often challenging for complete regeneration and this necessitate the use of newer adjuncts. This review highlights the newer periodontal regenerating LDD agents, their mechanism of action, challenges in periodontal regeneration and future avenues of research.