Plaque Biofilm Research Articles

The effect of the combined use of silver diamine fluoride and potassium iodide in disrupting the plaque biofilm microbiome and alleviating tooth discoloration: A systematic review.

Silver diamine fluoride (SDF) is used in minimally invasive dentistry for arresting dental caries. However, discoloration of teeth is a significant side effect that has limited the use of SDF. Hence, the application of potassium iodide (KI) following SDF has been proposed to ameliorate the staining. Although antimicrobial activity is one of the major mechanisms of the caries-arresting effect of SDF, the antimicrobial potency of SDF/KI combination is unclear. Thus, the primary objective of this systematic review was to appraise the studies on the antimicrobial efficacy of SDF/KI combination on cariogenic microbes. The secondary objective was to summarize the evidence on the potential of KI in reducing the discoloration associated with the application of SDF. Electronic databases of Medline via PubMed, Cochrane Library, Web of Science, and EBSCO host were searched for English language manuscripts from January 2005 to 15th November 2020. The reference lists of these manuscripts were manually searched for additional studies. Twelve studies were included in the final analysis, seven of which have investigated the antimicrobial efficacy of SDF/KI, and the rest have examined the anti-staining potential of KI. The exploratory findings from the reviewed articles revealed the promising antimicrobial potential of SDF/KI on cariogenic microbes associated with dentine caries. There is, however, contradictory evidence on the effect of SDF/KI on tooth color. The reviewed in-vitro studies indicated significant effectiveness of KI in preventing staining. A clinical trial on primary dentition showed 25% reduction in the incidence of staining by SDF after applying KI, while a clinical study on root caries in adults showed no significant effect. Within the methodological limitations of this review, we conclude that for arresting dental caries, SDF could be combined with KI, as there may be a lower likelihood of staining. Further, well-designed clinical trials on the antimicrobial and anti-staining effect of SDF/KI are needed to obtain more robust evidence.

Evaluation of Mouthwash Containing Citrus hystrix DC., Moringa oleifera Lam. and Azadirachta indica A. Juss. Leaf Extracts on Dental Plaque and Gingivitis.

Oral hygiene and control of microbial plaque biofilm formation are effective methods for preventing gingivitis. Mouthwashes containing leaf extracts of the medicinal plants Citrus hystrix DC. (KL), Moringa oleifera Lam. (MO) and Azadirachta indica A. Juss. (NE) were assessed for oral healthcare and gingivitis adjunctive treatment. Three types of mouthwash were developed; KL, a combination of KL and MO (KL + MO), and a combination of KL, and NE (KL + NE). The mouthwashes were tested in vivo on 47 subjects with gingivitis who were allocated into five groups as (i) placebo, (ii) KL, (iii) KL + MO, (iv) KL + NE, and (v) 0.12% chlorhexidine gluconate (CHX). Participants were instructed to rinse with herbal mouthwash twice daily for two weeks. Gingival index (GI), plaque index (PI), and oral microbial colonies were measured at baseline and 15 days. Results showed that GI and PI of groups (ii)–(iv) significantly decreased over the placebo group, while accumulative reduction percentages of both Staphylococcus spp. and Candida spp. were found in groups (iii) and (iv). Findings indicated that the herbal mouthwashes reduced GI and PI, and showed potential as oral healthcare products.

Treatment of dental plaque biofilms using photodynamic therapy: a randomised controlled study

IntroductionPhotodynamic therapy (PDT) is a treatment modality involving a dye that is activated by exposure to light of a specific wavelength in the presence of oxygen to form oxygen species causing localised damage to microorganisms.AimTo determine the most effective bactericidal incubation and irradiation times of erythrosine-based PDT on in vivo-formed dental plaque biofilms.MethodsA randomised controlled study; 18-healthy adult participants wearing intraoral appliances with human enamel slabs to collect dental plaque samples in two separate periods of two weeks each for use in arm-1 and arm-2. These accumulated dental plaque samples were treated with PDT under different experimental conditions. Incubation times with photosensitiser (erythrosine) of 15 min and 2 min were used in arm-1 and arm-2, respectively, followed by light irradiation for either 15 min (continuous) or as a fractionated dose (5 × 30 sec). Following treatment, percentage reductions of total bacterial counts were compared between the different groups. In addition, confocal laser scanning microscopy (CLSM) and LIVE/DEAD® BacLight™ Bacterial Viability Kit were used to visualise the effect of PDT on in vivo-formed biofilms.ResultsSignificant reductions in the percentage of total bacterial counts (~93–95%) of in vivo-formed biofilms were found when using either 2 min or 15min incubation times and applying 15 min continuous light. Although when applying fractionated light, there was more cell death when 15 min incubation time was used (~ 91%) compared with the 2 min incubation time (~ 64%). CLSM results supported these findings.ConclusionImproving the clinical usefulness of PDT by reducing its overall treatment time seems to be promising and effective in killing in vivo-formed dental plaque biofilms.

MICRO BIOLOGY OF PERIODONTAL DISEASE- A REVIEW

Periodontal diseases are inflammatory and destructive diseases of the dentogingival complex associated with specific periodontal pathogens inhabiting periodontal pockets. Periodontal diseases lead to damage of the periodontal tissues supporting the teeth (bone and connective tissue) and affect the quality of life of the affected individuals: poor alimentation, tooth loss, social and financial problems. Although it is generally considered that the disease has multifactorial etiology, data show that some specific Gram-negative microorganisms in the subgingival plaque biofilm play a major role in the initiation and progression of periodontitis. Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia form a consortium in the subgingival biofilm and are regarded as the principal periodontopathogenic bacteria. Other microorganisms that have been implicated as predominant species in the disease process are: Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Prevotella intermedia, Campylobacter rectus, Peptostreptococcus migros, Eikenella corrodens. In periodontitis, the initiation of the disease is the colonization of the tissues by these pathogenic species. The next step is bacterial invasion or invasion by pathogenic products into the periodontal tissues, interactions of bacteria or their substances with host cells, and this directly/indirectly causes degradation of the periodontium, resulting in tissue destruction.
 Keywords: periodontal disease, periodontal pathogens, microbiology.

The feasibility of phage therapy for periodontitis.

Periodontitis, a chronic progressive inflammation caused by plaque biofilm, is the main cause of tooth loss in adults. For certain refractory periodontitis cases, it is difficult to achieve a good curative effect using the existing periodontal treatment approaches, which may be due to periodontal pathogenic mechanism in the affected periodontal tissue that the host cannot resist and eliminate. Various pieces of evidence collectively revealed that most studies are focusing on phages in periodontal disease. Several studies have reported periodontitis treatment using phage therapy, highlighting its features including specificity, rapid propagation, and effectiveness on bacteriophage biofilms. In this study, we focus on these reports, aiming to lay the foundation for improved periodontal treatment approaches.

Virtual Screening and Biological Evaluation of Anti-Biofilm Agents Targeting LuxS in the Quorum Sensing System

Biofilm formation is considered as a crucial factor in various oral diseases, such as dental caries. The quorum sensing (QS) signaling system was proved to have a crucial role in the microbial dental plaque biofilm formation of Streptococcus mutans ( S. mutans). LuxS was critical to regulating the QS system and survival of the bacterium, and, therefore, compounds which target LuxS may be a potential therapy for dental caries. The binding activities of 37,170 natural compounds to LuxS were virtually screened in this study. Baicalein and paeonol were chosen for further research of the binding mode and ΔG values with LuxS. Both baicalein and paeonol inhibited the biofilm formation without influence on the growth of S. mutans. Baicalein also distinctly reduced the production of both rhamnolipids and acids. The results provide us with a new approach to combat dental caries instead of the traditional use of antibacterial chemicals.

Clinico-microbiological Efficacy of Indocyanine Green as a Novel Photosensitizer for Photodynamic Therapy among Patients with Chronic Periodontitis: A Split-mouth Randomized Controlled Clinical Trial.

Objective:Conventional nonsurgical periodontal therapy, i.e., scaling and root planing (SRP), is not sufficient to completely eradicate the microorganisms present in dental plaque biofilm due to the incapability of instruments to reach the inaccessible areas of a tooth with anatomical variations. Hence, to increase the effectiveness of SRP, many adjunctive treatment strategies are proposed, including photodynamic therapy (PDT). Therefore, the purpose of this study was to determine the clinical and microbiological efficacy of PDT using Indocyanine green (ICG) as a novel photosensitizer for the treatment of chronic periodontitis.Materials and Methods:Twenty individuals who fulfilled the eligibility criteria were enrolled for this randomized controlled clinical trial using split-mouth design. Treatment sites from each individual were randomly allocated into two groups: SRP was done for the sites of the control group and an additional session of PDT using ICG was performed for the sites of the test group. Subgingival plaque samples were collected from both the sites and sent for quantitative analysis of Treponema denticola, Porphyromonas gingivalis, and Tannerella forsythia using real-time polymerase chain reaction (RT-PCR) technique. Probing pocket depth (PD), clinical attachment loss (CAL), and count of all the three microorganisms were assessed at baseline and after 3 months.Results:After 3 months, PD and CAL showed statistically significant improvement in the test sites (P < 0.001) compared to the control sites. However, the differences in the microbiological parameters were statistically nonsignificant between the groups.Conclusion:ICG as a photosensitizer may enhance the outcomes of SRP and can be used for PDT for the nonsurgical management of periodontal diseases.

Clinical, bacterial, and inflammatory outcomes of indocyanine green-mediated photodynamic therapy for treating periimplantitis among diabetic patients: A randomized controlled clinical trial

Background This 6-months randomized controlled clinical trial aimed to assess the efficacy of indocyanine green mediated photodynamic therapy (ICG-PDT) as an adjunct to peri‑implant manual debridement (PIMD) versus PIMD alone among Diabetes Mellitus (DM) patients in the treatment of peri‑implantitis.Methods A total of 48 DM patients having 64 implants were treated with either ICG-PDT + PIMD (n = 35 implants) or PIMD alone (n = 29 implants). Clinical (probing depth [PD], bleeding on probing [BOP], and plaque index [PI]) and radiographic (peri‑implant crestal bone loss [PCBL]) peri‑implant variables were recorded. Bacterial species including Porphyromonas gingivalis and Treponema denticola were evaluated from peri‑implant plaque biofilms. Levels of interleukin (IL)-1β and IL-6 were assessed after the collection of peri‑implant sulcular fluid. All the evaluations were carried out at baseline, 3- and 6-months. The significance level was set to p < 0.05.Results All clinical parameters significantly reduced within both treatment groups (P<0.05). Intra-group comparison indicates that there was statistically significant reduction in PD and suppuration for ICG-PDT group (P<0.05). There was a statistically significant difference in the BOP between ICG-PDT and PIMD groups at both follow-up periods (P<0.001). However, there was a significant difference for PD (P = 0.001), suppuration (P = 0.01), and PCBL (P = 0.04) on 6 months follow-up between ICG-PDT and PIMD groups, respectively. Only ICG-PDT showed a significant reduction in P. gingivalis and T. denticola on both 3 months and 6 months follow-up compared to baseline. PIMD showed a statistically significant reduction only on 3 months follow-up compared to baseline. This reduction was maintained for both the species when dental implants were treated with ICG-PDT. However, PIMD failed to maintain this reduction until 6 months. Only at 3 months assessment that both treatment groups showed statistically significant reduction in IL-1β and IL-6 with no significant difference between the groups. Both biomarkers failed to maintain the reduction in both groups and significantly increased levels for IL-1β was noted at 6 months follow upConclusion Multiple application of indocyanine-green mediated photodynamic therapy resulted in improved clinical and microbial parameters among type 2 DM subjects in the treatment of peri‑implantitis.This clinical trial was registered in the ClinicalTrials.gov Protocol Registration and Results System with registration record number: NCT04833569

Dynamic Observation of the Effect of Maternal Caries on the Oral Microbiota of Infants Aged 12-24 Months.

AimTo provide a dynamic description of the oral microbial composition in mothers with and without dental caries and their children aging 12-24 months.MethodologyA total of 20 pairs of mothers and their children aged 12 months were included and followed up at 18 and 24 months of age. Ten mothers with dental caries(MEG) and their children(CEG) were in the exposure group, and ten caries-free mothers(MCG) and their children(CCG)in control group. Supragingival plaque biofilm samples were collected and DNA was extracted for bacterial 16S rRNA gene sequencing.ResultsA total of 18 pairs completed follow-ups. At a 3% divergence level, the number of common operational taxonomic units found between the mothers and children increased as the children aged. Proteobacteria, Bacteroidetes, Firmicutes, Fusobacteria, and Actinobacteria accounted for more than 80% phyla of each group. A microbial community structure analysis showed that the differences between mothers and children were significant in all groups except for the MEG24 and CEG24 groups.ConclusionsOral microbiota of children was more like their mothers’ with increasing age, regardless of whether the mothers had dental caries. Mothers with dental caries may have a greater influence on the oral microbiota of children’s than those without dental caries as children age.

Taxonomic and Gene Category Analyses of Subgingival Plaques from a Group of Japanese Individuals with and without Periodontitis.

Periodontitis is an inflammation of tooth-supporting tissues, which is caused by bacteria in the subgingival plaque (biofilm) and the host immune response. Traditionally, subgingival pathogens have been investigated using methods such as culturing, DNA probes, or PCR. The development of next-generation sequencing made it possible to investigate the whole microbiome in the subgingival plaque. Previous studies have implicated dysbiosis of the subgingival microbiome in the etiology of periodontitis. However, details are still lacking. In this study, we conducted a metagenomic analysis of subgingival plaque samples from a group of Japanese individuals with and without periodontitis. In the taxonomic composition analysis, genus Bacteroides and Mycobacterium demonstrated significantly different compositions between healthy sites and sites with periodontal pockets. The results from the relative abundance of functional gene categories, carbohydrate metabolism, glycan biosynthesis and metabolism, amino acid metabolism, replication and repair showed significant differences between healthy sites and sites with periodontal pockets. These results provide important insights into the shift in the taxonomic and functional gene category abundance caused by dysbiosis, which occurs during the progression of periodontal disease.

Dysbiosis revisited: Understanding the role of the oral microbiome in the pathogenesis of gingivitis and periodontitis: A critical assessment.

This commentary provides background, historical context, and a critical assessment of the concept that microbial dysbiosis drives the pathogenesis of periodontal diseases. It is long known that periodontal pathogenesis is dependent on tooth-borne microbial biofilms (dental plaque) that trigger host inflammation resulting in periodontal destruction and tooth loss in some patients. Ecological principles governing plaque biofilm development, along with localized host responses, are both rooted in evolution. Interpretation of available evidence suggests that, in most patients, alveolar bone loss results from interactions of a highly diverse commensal microbiota with the host, and not from "overgrowth" of a few "pathobionts" that results in a "dysbiosis." Most previously described dysbiotic chronic diseases, for example, inflammatory bowel diseases and dermatitis, are characterized by decreased microbial diversity (likely due to frank overgrowth of one or a few microbial taxa). Most common forms of periodontitis do not appear to conform to this general principle, and the associated microbiome in fact almost always shows increased bacterial diversity compared with periodontal health. This diversity is driven by interactions of genetic and environmental factors working in concert within specific windows of time. Periodontal pathogenesis is likely the result of "personalized pathology," insofar as each patient likely has a variable constellation of microbes and host risk factors influencing specific tissue sites where disease activity occurs, and during a limited window of time (a tissue-destructive "burst"). The concept of cooperative virulence of higher abundance commensals in periodontal pathogenesis, which does not conform to the model of dysbiosis observed for other diseases, is discussed.

Biopsied non-dental plaque-induced gingival diseases in a Chinese population: a single-institute retrospective study

BackgroundWhile inflammatory diseases such as gingivitis and periodontitis induced by dental plaque biofilms constitute the majority of gingival lesions, gingiva can also be affected by a variety of diseases with aetiologies different from bacterial biofilms. The aim of this study was to retrospectively analyze the frequency and distribution of non-dental plaque-induced gingival diseases (NDPIGDs) in the Chinese population in a single institute.MethodsA total of 6859 samples of biopsied gingival diseases during the period 2000–2019 were obtained from the Department of Pathology, Peking University Hospital of Stomatology. Lesions were categorized by histopathological diagnosis, pathological characteristics and the new classification of gingival health and gingival diseases/conditions. Demographic information, such as gender, location, and age, were also analyzed.ResultsAmong 6859 biopsied NDPIGD samples, the five most frequent diagnoses included oral squamous cell carcinoma (OSCC, n = 2094), fibrous hyperplasia (n = 2026), pyogenic granuloma (n = 478), epithelial dysplasia (n = 477), and epithelial hyperplasia/hyperkeratosis (n = 436). All types could be grouped into nine categories according to their pathological characteristics. The most common biopsied NDPIGDs category was “hyperplastic lesions” (n = 2648, 38.61%), followed by “malignant neoplasms” (n = 2275, 33.17%). The most common diagnosis types in each category were fibrous hyperplasia and OSCC. Of all NDPIGDs, most lesions could be categorized into the new classification of gingival health and gingival diseases/conditions; only 7.07% did not fit the current classification system.ConclusionsThe present study is the first report on the frequency and distribution of biopsied NDPIGDs in a Chinese population. Unlike previous studies, the most prevalent categories were “hyperplastic lesions” and “malignant neoplasms”. The proportion of “malignant neoplasms” and “oral potentially malignant disorders” was remarkably higher than in previous researches. Nevertheless, the study provided epidemiological information on many NDPIGDs, which could be useful for future health policies as well as screening programs.

Local Sustained Delivery of Anti-IL-17A Antibodies Limits Inflammatory Bone Loss in Murine Experimental Periodontitis.

Periodontal disease (PD) is a chronic destructive inflammatory disease of the tooth-supporting structures that leads to tooth loss at its advanced stages. Although the disease is initiated by a complex organization of oral microorganisms in the form of a plaque biofilm, it is the uncontrolled immune response to periodontal pathogens that fuels periodontal tissue destruction. IL-17A has been identified as a key cytokine in the pathogenesis of PD. Despite its well documented role in host defense against invading pathogens at oral barrier sites, IL-17A-mediated signaling can also lead to a detrimental inflammatory response, causing periodontal bone destruction. In this study, we developed a local sustained delivery system that restrains IL-17A hyperactivity in periodontal tissues by incorporating neutralizing anti-IL-17A Abs in poly(lactic-coglycolic) acid microparticles (MP). This formulation allowed for controlled release of anti-IL-17A in the periodontium of mice with ligature-induced PD. Local delivery of anti-IL-17A MP after murine PD induction inhibited alveolar bone loss and osteoclastic activity. The anti-IL-17A MP formulation also decreased expression of IL-6, an IL-17A target gene known to induce bone resorption in periodontal tissues. This study demonstrates proof of concept that local and sustained release of IL-17A Abs constitutes a promising therapeutic strategy for PD and may be applicable to other osteolytic bone diseases mediated by IL-17A-driven inflammation.

RvE1 Impacts the Gingival Inflammatory Infiltrate by Inhibiting the T Cell Response in Experimental Periodontitis.

Periodontitis is a chronic inflammatory disease associated with the formation of dysbiotic plaque biofilms and characterized by the progressive destruction of the alveolar bone. The transition from health to disease is characterized by a shift in periodontal immune cell composition, from mostly innate (neutrophils) to adaptive (T lymphocytes) immune responses. Resolvin E1 (RvE1) is a specialized pro-resolution mediator (SPMs), produced in response to inflammation, to enhance its resolution. Previous studies have indicated the therapeutic potential of RvE1 in periodontal disease; however, the impact of RvE1 in the microbial-elicited osteoclastogenic immune response remains uncharacterized in vivo. In the present study, we studied the impact of RvE1 on the gingival inflammatory infiltrate formation during periodontitis in a mouse model. First, we characterized the temporal-dependent changes of the main immune cells infiltrating the gingiva by flow cytometry. Then, we evaluated the impact of early or delayed RvE1 administration on the gingival immune infiltration and cervical lymph nodes composition. We observed a consistent inhibitory outcome on T cells -particularly effector T cells- and a protective effect on regulatory T cells (Tregs). Our data further demonstrated the wide range of actions of RvE1, its preventive role in the establishment of the adaptive immune response during inflammation, and bone protective capacity.

EFFECTIVENESS OF PROBIOTICS AS AN ADJUNCT IN PERIODONTAL CARE

Relevance of the problem. Periodontitis is a multifactorial inflammatory disease related with dysbiotic plaque biofilms and characterized by progressive destruction of the tooth-supporting apparatus. Treatment of periodontitis aims to prevent further disease progression, to minimize symptoms and perception of the disease, possibly to restore lost tissues and to support patients in maintaining a healthy periodontium. Scaling and root planning (SRP) is the gold standard for the treatment of periodontitis. For the reduction in bacterial recolonization probiotics have been suggested as promising agents not only to retard recolonization, but also to increase the number of beneficial bacteria and to modulate immunological parameters in the prevention and treatment of periodontal disease. Aim of the work. To find out and assess the data of clinical trials that proposes clinical outcomes of the adjunctive use of probiotic for 3 months after SRP in comparison to SRP combined with a placebo. Tasks: 1) ascertain and assess the recolonization of bacteria after active treatment of periodontitis; 2) clarify and evaluate clinical variables improvement after the usage of local adjunctives; 3) find out and assess the distinction between different probiotics strains. Material and methods. This literature review has been carried out in accordance with the PRISMA Statement [23]. Electronic literature review was performed using MEDLINE and ELSEVIER databases and the selection of the articles, published in English between 2010 and 2020 year. The search for publications was based on keywords and their combinations: chronic periodontitis, scaling and root planning, adjunct care, probiotics, supplements. Results. This literature review includes eight suitable studies that met the inclusion criteria. Conclusions. The qualitative findings of the studies showed that major part of the included trials reported significant improvement in clinical periodontal parameters in periodontitis patients with the adjunctive use of probiotics compared with control group. 75 % of included studies made with L. reuteri found probiotic containing L. reuteri usage as an adjunct therapy to be significant in the improvement of clinical parameters. Probiotic therapy could be used for managing periodontal diseases. This review puts a stress on L. reuteri effectiveness. However, further studies are needed to substantiate its longitudinal effect.

Research progress in the interaction between Treponema denticola and microorganisms of subgingival plaque

Treponema denticola (Td) is a gram-negative anaerobic bacterium closely related to the occurrence and development of periodontal disease and it accounts for a considerable proportion of mature plaque. As a later colonizer of the subgingival plaque biofilm, Td may have complex interactions with earlier and concurrent colonists including symbiotic relationship as while as synergistic or antagonistic effects under the regulation of quorum sensing molecules. Adhesin and coaggregation, mediated by a series of surface molecules, are the basis of the interaction. These interactions are ultimately manifested as gene expression changes in metabolism and virulence, in which are mainly metabolism changes with up- or down-regulation of multiple enzymes related to amino acid metabolism. This article reviews the related researches on the interaction between Td and microorganisms of subgingival plaque.

Recent Development of Active Ingredients in Mouthwashes and Toothpastes for Periodontal Diseases.

Periodontal diseases like gingivitis and periodontitis are primarily caused by dental plaque. Several antiplaque and anti-microbial agents have been successfully incorporated into toothpastes and mouthwashes to control plaque biofilms and to prevent and treat gingivitis and periodontitis. The aim of this article was to review recent developments in the antiplaque, anti-gingivitis, and anti-periodontitis properties of some common compounds in toothpastes and mouthwashes by evaluating basic and clinical studies, especially the ones published in the past five years. The common active ingredients in toothpastes and mouthwashes included in this review are chlorhexidine, cetylpyridinium chloride, sodium fluoride, stannous fluoride, stannous chloride, zinc oxide, zinc chloride, and two herbs—licorice and curcumin. We believe this comprehensive review will provide useful up-to-date information for dental care professionals and the general public regarding the major oral care products on the market that are in daily use.

Understanding the Matrix: The Role of Extracellular DNA in Oral Biofilms.

Dental plaque is the key etiological agent in caries formation and the development of the prevalent chronic oral inflammatory disease, periodontitis. The dental plaque biofilm comprises a diverse range of microbial species encased within a rich extracellular matrix, of which extracellular DNA (eDNA) has been identified as an important component. The molecular mechanisms of eDNA release and the structure of eDNA have yet to be fully characterized. Nonetheless, key functions that have been proposed for eDNA include maintaining biofilm structural integrity, initiating adhesion to dental surfaces, acting as a nutrient source, and facilitating horizontal gene transfer. Thus, eDNA is a potential therapeutic target for the management of oral disease–associated biofilm. This review aims to summarize advances in the understanding of the mechanisms of eDNA release from oral microorganisms and in the methods of eDNA detection and quantification within oral biofilms.

Local Drug Delivery to Treat Chronic Periodontitis

Periodontal disease is a chronic inflammatory disease of periodontium characterized by increased pocket depth, clinical attachment loss, sulcular bleeding, and bone loss. Bacterial plaque bio-film stimulates host derived enzymes and cytokines like TNF , IL-1 and matrix metalloproteases that lead to destruction of periodontium, collagenolytic activity, decreased bone mineral density, intra-bony defects and ultimately bone loss. Chronic periodontitis is managed by conventional and systemic approach, where conventional therapy comprises of scaling and root planning. Mechanical debridement of plaque also requires an adjunct to eradicate the root cause of progressing disease. Hence, worldwide paradigm has shifted towards novel therapies; therefore, local delivery of drug is now preferred due to direct access to target sites with considerably less adverse effects and a better approach to deal with chronic periodontitis. The nano-particle technology to treat periodontitis is still an emerging and promising strategy for the management of disease with the provision of minimal dose, less invasive procedure and clinical efficacy.

Oral biofilms revisited: A novel host tissue of bacteriological origin.

The central theme of this volume of Periodontology 2000 is that the microbial dental plaque biofilm, specifically the subgingival dental plaque biofilm, mimics a human tissue in both structure and function. As a basis for this assertion we use the definition of a tissue as an aggregate of similar cells and cell products forming a defined structure with a specific function, in a multicellular organism. Accordingly, we propose that the dental plaque biofilm represents an acquired human tissue largely of bacterial origin that maintains the health of gingival tissue. Furthermore, we acknowledge that disease can be defined as a deviation from the normal structure or an interruption to the function of any body part, organ, or system, and that is manifested by a characteristic set of symptoms and signs whose etiology, pathology, and prognosis may be known or unknown. Therefore, in this volume we present the concept that periodontitis is a disruption of the normal function of the healthy subgingival plaque biofilm with concomitant disruption to its functional properties in relation to innate defense surveillance and tissue maintenance, leading to excessive, deregulated inflammation and tissue destruction.