Chronic periodontitis is an infectious disease resulting in inflammation of the supporting tooth structures, leading to progressive attachment loss and destruction of alveolar bone. Periodontal disease initiation is by local accumulation of bacteria and their metabolic products leading to apical migration of the junctional epithelium along the root surface, deepening the gingival crevice leading to periodontal pocket formation and associated attachment loss, which is the hallmark lesion of periodontal disease.

The Microbiology of periodontal infections is complicated for which numerous bacterial agents have been implicated in their etiology . Porphyromonas gingivalis has been known as a major etiologic agent in the development of adult periodontitis. Porphyromonas gingivalisis a highly adapted pathogen that is armed with a number of putative virulence factors such as fimbriae, a polysaccharide capsule, hemagglutination and hemolysis activities  that enable this organism to cause disease.  

 The aim of the therapy is to reduce the    etiologic factors below the threshold capable of producing breakdown, allowing repair of the affected region at a diseased site. The regeneration of damaged periodontal structures can be facilitated through targeted interventions, including nonsurgical periodontal therapy such as scaling and root planing (SRP) combined with adjunctive chemotherapeutic agents, or through surgical approaches.

Unfortunately, in some instances, the intricate root anatomy and lesion contours can pose challenges to treatment, hindering the effective reduction of bacterial load and preventing the tooth surface from achieving optimal biological compatibility.This could be related to the persistence of pathogens in the pocket after treatment or to the production of specific virulence factors by the bacteria interfering with the host defense. In this context,it is evident that antimicrobial agents are of great interest and are considered valuable adjuncts to mechanical periodontal therapy. These treatments are categorized based on their route of administration as either systemic or local drug delivery methods. 

 To overcome the limitations associated with systemic administration, local delivery systems incorporating antibiotics or antiseptics were developed. These systems enable targeted delivery of therapeutic agents directly to the affected periodontal sites, minimizing systemic exposure and side effects.

In the past years, among the various available antimicrobial drugs therapeutic effect of ozonated oil was attributed to its antibacterial, antifungal, antiviral, antiparasitic, anti-hypoxic, analgesic and immuno-modulatory effects on biological systems. Ozone therapy has diverse applications across various dental specialties. In periodontics, subgingival application of ozonated oil in both human and animal models has demonstrated its ability to enhance cellular function, accelerate tissue healing, and eliminate defective tissue within the biological system. This process supports the survival and rapid multiplication of healthy cells. Apart from Ozonated oil, Ozonated olive oil  has a valuable antimicrobial activity against bacteria, fungi, viruses.

 Extra virgin olive oil (EVOO) contains over 36 phenolic compounds, all of which offer health benefits. Among them, oleocanthal stands out for its potent natural anti-inflammatory properties. Unique to olive oil, oleocanthal exhibits anti-inflammatory effects similar to the non-steroidal anti-inflammatory drug (NSAID) ibuprofen. Unlike NSAIDs, which are associated with side effects such as gastric irritation, nausea, and vomiting, olive oil provides a safe, natural alternative. Oleocanthal exerts its effect by inhibiting cyclooxygenase 1 and 2 (COX-1 and COX-2) enzymes in a dose-dependent manner. 

Additionally, ozone plays a significant role in oral health by effectively inhibiting dental plaque formation and reducing both Gram-positive and Gram-negative pathogens. As an antimicrobial agent, ozone possesses oxidative power 1.5 times greater than chloride. Its antimicrobial action stems from its ability to disrupt bacterial cytoplasmic membranes through ozonolysis of double bonds, leading to alterations in cytoplasmic contents. Notably, this mechanism does not harm human body cells, as mammalian cells possess antioxidant defenses that protect against oxidative damage.

Ozone exhibits strong antibacterial properties by disrupting the structural integrity of bacterial cell membranes through the peroxidation of phospholipids. Furthermore, its ability to inhibit the NF-kappa B system contributes to its potent anti-inflammatory effects, effectively helping to suppress disease activity.

Ozone influences cellular and humoral immune system. Ozone enhances the immune response by promoting the proliferation of immunocompetent cells and boosting immunoglobulin synthesis. It also stimulates macrophage activity and improves the susceptibility of microorganisms to phagocytosis. Additionally, ozone facilitates the production of biologically active compounds such as interleukins, leukotrienes, and prostaglandins, which play a crucial role in alleviating inflammation and pain. Due to its negative charge (basic nature), ozone is naturally attracted to infected or inflamed areas, which are positively charged (acidic), aiding in targeted therapeutic action. 

Through acceleration of healing, reduction of microbial infection, modulation of the inflammation phase, and enzymatc reactions in oxygen metabolism ozonated olive oil represents an efficient and  cheap alternative to be used in the dental field.

Various local drug delivery system for treating periodontitis includes-Fibers, Films, Injectable systems, Gels, Strips and Compacts, Vesicular systems, Microparticle system, Nanoparticle system.A far more widely used form of intra-pocket delivery device has been in the shape of film,prepared either by solvent casting or direct milling.

Film-based drug delivery systems consist of a polymer matrix in which the medication is evenly dispersed, allowing for controlled release through diffusion, dissolution, or erosion. This formulation offers several benefits for intra-pocket application, including ease of customization to fit the specific size and shape of the periodontal pocket hence it can be conveniently placed at the pocket’s base with minimal patient discomfort, ensuring effective and localized drug administration.

Films of various polymers have been made for the controlled release of therapeutic agents. .Biodegradable and mucoadhesive polymers such as alginate, chitosan, and gelatin (GE) have gained popularity as a vehicle in slow drug release device to deliver the antimicrobial agents.Gelatin is a naturally occurring biodegradable, nontoxic, mucoadhesive material obtained by controlled hydrolysis of animal skin, bones and connective tissues.GE readily forms films and it is frequently utilized as films. Because of its biodegradability, biocompatibility, and nonimmunogenicity, GE is widely used in pharmacy and medicine as a carrier in controlled release drug delivery systems, dressings for wound healing, and so on.

Chitosan, a natural polymer obtained by alkaline deacetylation of chitin, is nontoxic, biocompatible, biodegradable and moreover metabolized by certain human enzymes, especially lysozyme. These properties make chitosan a good candidate for conventional as well as novel drug delivery systems.Further, it can be easily casted into film and acts as a promising matrix for controlled and sustained drug release and possesses excellent film forming properties . Its biodegradable nature has gained significant attention and made it a high patient-compliant drug delivery device for periodontitis. The device dissolves within the pocket, and there is no need of the patient to revisit clinic for removal of the device.Chitosan has demonstrated antimicrobial efficacy against P. gingivalis, with its effectiveness being more pronounced in high molecular weight forms. Further, local intra-pocket administration of such devices requires less dose, little or no systemic uptake, and therefore minimized side effects of loaded antibiotics.

Periodontitis is caused by various bacteria, with Porphyromonas gingivalis recognized as the primary pathogen driving disease progression. Rapid detection of these pathogenic microorganisms is crucial for effective infection management.The culture-dependent techniques have been used traditionally to detect oral microbiota by which only cultivable and predominant bacteria could be identified.Over the years, molecular techniques such as PCR and real-time PCR have helped in the easy and quick detection of various oral pathogens.

 Polymerase Chain Reaction (PCR) is an in vitro technique for amplifying specific DNA sequences, playing a crucial role in biology, medicine, and chemistry. Traditionally, PCR was designed for qualitative analysis, providing a binary result—indicating only the presence or absence of a target gene. However, in clinical and research applications, quantifying DNA sequences is often necessary, particularly for disease diagnosis and genetic analysis

To address the above issues of traditional PCR for DNA quantification various PCR methods have been developed, including  Quantitative PCR,real-time PCR(RT-PCR),  immuno-PCR, nested PCR, in situ PCR, and allele-specific PCR. was proposed. Quantitative PCR (qPCR) can be classified into three main strategies: semiquantification, relative quantification, and absolute quantification of which Semiquantification is commonly performed by integrating conventional PCR with gel electrophoresis, where the fluorescence intensity of gel bands is used to estimate the amount of amplified DNA .While  RT-PCR provides precise quantification, it requires expensive equipment and specialized fluorescent probes, making it less accessible for routine use in many laboratories.In contrast, conventional PCR-based semiquantification offers a cost-effective alternative. Given the financial and technical constraints associated with RT-PCR, conventional PCR remains a practical and efficient method for semiquantitative DNA analysis in many settings.

The need for this study arises from the limited literature on the comparative evaluation of clinical efficacy of chitosan and gelatin films incorporating ozonated olive oil as a local drug delivery system in treating chronic periodontitis and evaluating their microbiological efficacy using  semi-quantification method  by conventional PCR .