Article written by Beata Knysak for dentists, dental hygienists and therapists.

Periodontal disease is a major public health concern due to its high prevalence. According to the data severe periodontitis is the sixth-most prevalent condition in the world [1]. In the United Kingdom, 62% of adults under 40 years of age are affected by moderate periodontal disease [2] and throughout the Covid-19 pandemic we have seen an immense increase in the number of patients with periodontal tissue breakdown and tooth loss.

While there is an increase in life expectancy and a significant decrease in tooth loss, periodontal disease puts a burden on the national healthcare systems across the globe.

Although bacteria arising from plaque is the main aetiological factor of periodontal disease, the host’s immune inflammatory response is accountable for the majority of the destructive changes seen in periodontal tissues. Even in healthy periodontium, host immune cells are continuously present, supporting the balance between microbial plaque and the host [6]. Any interactions between the host and oral microbiota will either support the homeostasis or results in dysbiosis within the community of pathogenic microorganisms [7].

Periodontal health-associated commensals are vital in protecting this equilibrium by for example inhibiting the growth of periopathogenic microorganisms. However, quantitative and qualitative changes within subgingival plaque biofilm may lead to disturbed homeostasis, which subsequently leads to the onset of the periodontal disease with various degrees of periodontal tissue breakdown.

This is not a continuous process but alternates between a period of inactivity and aggravation and it can be affected by local and systemic factors [3&4]:

• Microbial plaque-biofilm burden
• Patient’s age, ethnicity, genetic predisposition and patient’s immune response
• Systemic diseases i.e., Diabetes Mellitus, Osteoporosis
• Tooth morphological factor: i.e., defective restoration, malocclusion, bulbous crowns and dental bridge that unbales the patient to perform an adequate oral hygiene routine
• Patient’s socio-economic factors i.e., education and access to dental care
• Life-style choices i.e., smoking, obesity, poor diet, stress, sleeping pattern,
• Deficiencies in patient’s oral hygiene routine.

If not treated, periodontal disease leads to connective tissue destruction and alveolar bone resorption that eventually results in tooth loss [5]. It negatively affects patient’s chewing function and aesthetics, it is a source of social inequality, and significantly impairs their quality of life.

The main objectives of non-surgical periodontal therapy (NSPT) are to provide the least invasive treatment that gives the patient the best and most predictable outcomes through the promotion of periodontal tissue regeneration and restoration of tooth function. After successful treatment, periodontal ligament (PDL) cells (fibroblasts) migrate and attach to the microorganism free root surface. They proliferate, differentiate and synthesise extracellular matrix proteins to form collagen fibres. It is crucial to obtain newly formed PDL to prevent apical migration of junctional epithelium and to allow regeneration of PDL, cementum and alveolar bone; therefore, the application of laser irradiation has been proposed to allow for the compatibility of root surfaces with regenerative processes.

An increasing number of studies have demonstrated the benefits of adjunctive laser therapy in conventional NSPT due to its reported ability to significantly reduce pathogens, promote healing and to suppress the inflammatory cytokine cascade through to surgical ablation of diseased tissues [8]. As a result of its deeper penetration, diode laser has not only had bactericidal effects but also bio-stimulatory effects on periodontal ligament stem cells, osteoblasts and fibroblasts [9]. The Erbium Chromium: Yttrium Scandium Gallium Garnet (Er,Cr:YSGG) laser, however, allows selective subgingival biofilm and calculus ablation without causing any thermal side effects (carbonisation) or morphologic changes to the root surface to allow the attachment of these cells [10]. Also, when compared with conventional hand instrumentation, Er,Cr:YSGG laser therapy was not only found to promote PDL fibroblast cell migration and attachment, but it also increased the number of cells that differentiate in periodontal regeneration [11,12,13].

Although in the treatment of periodontal disease, surgical interventions (with the use of osseous graft material, barrier membranes or application of a biologically active material) deem to have more predictable outcomes than conventional NSPT, they may however, possess multiple shortfalls including high cost, painful healing and post-operative complications. Also, with regard to the application of local or systemic antibiotic there are multiple side-effects including antibiotic resistance, gastrointestinal complications or drug interactions.