The host and microbial response to non-surgical periodontal therapy

Johnston, William (2021) The host and microbial response to non-surgical periodontal therapy. PhD thesis, University of Glasgow.

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Background: Periodontitis is one of the most prevalent diseases of mankind, characterised by dysbiotic subgingival plaque biofilms and chronic gingival inflammation. If left untreated, inflammation results in irreversible bone resorption and tooth loss, with both nutritional and psychosocial consequences for patients. Periodontitis has become increasingly associated with systemic comorbidities including rheumatoid arthritis, suggesting it’s impact may extend beyond the oral cavity. Periodontal treatment involves mechanical biofilm disruption, which is often only partially successful. Moreover, potentially detrimental systemic effects have been reported following intensive full-mouth periodontal debridement. This thesis sought to evaluate the host and microbial response to non-surgical periodontal therapy.

Methods: Clinical parameters and samples were obtained from two independent clinical studies. The first was a longitudinal cohort study (n=42), the second was a randomised controlled trial with patients receiving full-mouth debridement performed exclusively with hand (n=19) or ultrasonic instruments (n=18).

Results: The cohort study demonstrated widespread improvement in periodontal clinical parameters. There were no changes in surrogate markers of systemic inflammation or autoimmunity at 90 day follow-up (chapter 2). There were notable alterations to local cytokine profiles (saliva/GCF), which were accompanied by shifts in the subgingival plaque microbiota (chapter 3). The second study evaluated the systemic inflammatory response following full-mouth debridement. Although treatment induced an increase in serum CRP at day 1, there were no differences between groups and the magnitude of response was markedly lower than has been previously reported (chapter 4). Hand and ultrasonic instruments also induced comparable clinical and microbial outcomes (chapter 5). Notably, in both studies, differences in the post-treatment subgingival plaque composition appeared independent of residual disease.

Conclusion: There were no differences in the systemic inflammatory response following hand or ultrasonic instrumentation, and the clinical significance of this systemic response must be further substantiated. There was disparity in microbial outcomes following NSPT, and future studies should seek to establish whether compositional differences dictate long-term disease recurrence.

Item Type: Thesis (PhD)
Qualification Level: Doctoral
Subjects: R Medicine > RK Dentistry
Colleges/Schools: College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing
Supervisor's Name: Culshaw, Professor Shauna, Sherriff, Dr. Andrea and Ramage, Professor Gordon
Date of Award: 2021
Depositing User: Theses Team
Unique ID: glathesis:2021-82651
Copyright: Copyright of this thesis is held by the author.
Date Deposited: 28 Jan 2022 13:54
Last Modified: 08 Apr 2022 16:55
Thesis DOI: 10.5525/gla.thesis.82651
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