Periodontitis is the primary cause for tooth loss which is described by the progressive deterioration of alveolar bone and connective tissue attachment. Periodontal therapy aims at arresting infection, restoring the lost tooth supporting structures and to maintain a healthy periodontium either by surgical/ non-surgical modalities. Among them, the goal of periodontal surgery is to alleviate the degeneration associated with the sites inaccessible for non-surgical therapy and having critical probing depth of greater than or equal to 5.4mm in progressive periodontal disease.

In order to accomplish this, access to the underlying root and bone surface for debridement has been an integral part of periodontal surgical therapy known as open flap debridement (OFD). This mechanical treatment alone will not be able to eliminate tissue invasive periodontal pathogens, which serve as nidus for recolonization and reinfection in the treated sites. Thus, to overcome these limitations, use of adjunctive modalities like antimicrobials, host-modulating agents, anti- inflammatory agents and autologous platelet concentrates have been used with variable results.

Diode laser with wavelength of 910- 980 nm is found to target the soft tissue which is diseased but without affecting the dental hard tissues. Increased reduction in colony forming unit (CFU) of obligate anaerobes were detected in low- level laser (LLLT) treated sites as an adjunct to flap surgery. Adequate sterilization, haemostasis and reduced inflammation, increases periodontal tissue attachment and less post- operative pain has been observed in surgical procedure with diode laser compared to that of conventional surgical therapy.

The second generation of platelet concentrates, known as platelet rich fibrin, is used as an autologous biological scaffold for periodontal therapy. PRF in conjunction with OFD showed improved clinical attachment level (CAL) as well as probing pocket depth (PPD) post-surgically. Intra-marrow penetration has synergized the effect of PRF matrix, aiding in periodontal regeneration of horizontal defect.

Among the PRFs, the newest Albumin- PRF has shown increased membrane stability for 4-6 months and enhanced wound healing by gradual release of growth factors. It also expressed increased fibroblast proliferation than i-PRF and clinically reduced oedema and decreased release of pro- inflammatory cytokines than L-PRF.

Biomarkers validate the best estimate of the prognosis unique to a site and the outcome of periodontal therapy. Hence, increased and decreased levels of these biomarkers become a significant tool in assessing the biological events that occur at molecular level in the pocket lining. When compared to healthy regions, it is discovered that the diseased periodontal tissues and gingival fluid have noticeably higher concentrations of the pro-inflammatory cytokine interleukin-1. Significant reduction in IL-1beta level was observed in chronic periodontitis patients following laser- assisted non-surgical therapy.

The most frequent issue confronting clinicians is chronic periodontitis with horizontal bone loss, although this condition has attracted very little attention. Till date, studies have shown improved clinical parameters by reduced inflammation with the use of lasers and better clinical and radiographic bone levels when PRF was used as an adjunct to OFD compared to OFD alone. As much as we are aware, no research has been done so far to assess the synergistic effect of low- level laser therapy and Alb-PRF in horizontal defect following open flap debridement.

Hence, the aim of this study is to evaluate the effect of low- level laser therapy as an adjunct to open flap debridement with and without albumin- platelet rich fibrin on clinical parameters and gingival crevicular fluid interleukin-1beta level in chronic periodontitis patients.