Rheumatoid arthritis and control of the periodontal infection: epidemiological evaluation and randomized clinical trial

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University of Pisa

Doctoral School of Clinical Pathophysiology

Coordinator: Prof. Fulvio Basolo

PhD Thesis

Rheumatoid arthritis and control of the

periodontal infection: epidemiological

evaluation and randomized clinical trial.

PhD Student Thesis coordinator

Dimitra Karapetsa Prof. Filippo Graziani

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Analytic abstract

Aim: (i) To assess the prevalence and severity of Periodontitis (P) among patients affected by rheumatoid arthritis (RA) and to describe their clinical and serological profile comparing it with a control population affected by RA but not suffering from P. (ii) To evaluate the possible beneficial additional value of non-surgical periodontal therapy on systemic markers of inflammation and clinical and serological parameters of RA.

Materials & Methods: Medical records of patients affected by RA from the outpatient clinics of Rheumatology and Dentistry and Oral Surgery of the University Hospital of Pisa were screened for inclusion and subjects were invited to participate and sign the informed consent. Included subjects underwent a full-mouth periodontal examination including probing depth, gingival recession, plaque index, bleeding on probing and a full rheumatologic visit. RA disease activity was scored with DAS28. Serum analyses investigated levels of rheumatoid factor (RF), anti-citrullinated protein antibodies (ACPAs), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and fibrinogen. Information concerning smoking, body mass index (BMI) and RA medical therapy (biological or disease-modifying antirheumatic drugs) was also collected.

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For the randomized clinical trial (RCT), subjects presenting with (i) at least 15 teeth, (ii) generalized severe periodontitis, that is interesting at least 25% of sites, and (iii) absence of non-surgical periodontal treatment in the 6 months preceding the beginning of the study underwent non-surgical periodontal treatment. RCT patients were randomly assigned to either immediate (test group) or delayed (control group), that is performed at the completion of the 3-month follow-up, non-surgical periodontal treatment. Periodontal and rheumatologic clinical and serological parameters were registered before and after treatment.

Results: The final cohort consisted of 92 patients with RA. Fifty subjects, representing 54.3% of the study sample, resulted affected by periodontitis (RA-P group), while the other 45.7% only had RA (RA group). Both groups were comparable for age, gender distribution and BMI and consisted of 20% of current smokers. The number of teeth present was statistically lower in the RA-P compared to the RA group (p < 0.05). DAS28 mean value (± standard deviation, SD) in RA-P group was 3.14 (± 1.1), while the respective value in the RA group was 2.81 (± 1.0); these differences were not statistically significant (p > 0.05). With regards to RA serological profile (RF and ACPAs), there were statistically more subjects seropositive for ACPAs in the RA group (66.7% versus 42%, p < 0.05) whereas no statistical differences were observed when

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comparing the seropositivity for RF of the two groups. Furthermore, the concentrations of the serum inflammatory biomarkers (CRP, ESR and Fibrinogen) in the two groups were comparable. Finally, patients with P and RA had an unadjusted OR = 2.4 (95% confidence interval [CI] 0.99 – 5.81) of presenting a moderate-severe DAS28 score (DAS28 ≥ 3.2); after adjusting for RA medication, FR, ACPAs, smoking status and gender the OR resulted 2.62 (95% CI 0.96 – 7.12).

For the RCT, a total of 16 subjects were included and completed the 3-month follow-up from January 2015 to December 2016. Non-surgical periodontal treatment produced significant clinical benefits in terms of standard periodontal parameters (p < 0.05). DAS28 mean (± SD) value in test group (immediate treatment) was 3.05 (± 1.1) at pre-treatment and 2.73 (± 1.2) post-treatment, while the respective values in the control group (delayed treatment) were 2.77 (± 1.3) at pre-treatment and 3.29 (± 1.5) post-treatment. These changes were not statistically significant (p > 0.05), but a trend of amelioration may be observed among the patients of the test group. With regards to serum levels of CRP, ESR, Fibrinogen, IL-6 and TNF-α no statistically significant differences between the two groups were observed 3 months after non-surgical periodontal treatment (p > 0.05).

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Conclusions: Among RA subjects a considerably higher prevalence of severe P has been observed. Furthermore, the clinical severity of RA appears to be strongly correlated with the clinical periodontal parameters and RA subjects also affected by P seem to have an OR of 2.62 for presenting with a moderate-severe RA (DAS28 score ≥ 3.2).

The non-surgical periodontal treatment appears to determine a trend for amelioration of DAS28 scores among RA patients with periodontitis without determining a statistically significant change in their serological profile. A larger study sample with a longer follow-up period is needed in order to better elucidate the effects of non-surgical periodontal treatment on the clinical and serological parameters of patients affected by rheumatoid arthritis.

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1. Introduction

1.1 Periodontitis

Periodontitis is an infectious disease defined by bacteria-mediated inflammation of the supporting tissues of the teeth that if left untreated may ultimately lead to the destruction of the attachment apparatus, culminating in tooth loss (Savage et al. 2009) (Figure 1 and Figure 2). Diagnosis of periodontitis is based on severity and extent of attachment loss (AL) and pocket probing depth (PPD) and it is generally categorized as mild, moderate and severe (Page & Eke 2007, Eke et al. 2012b). Severe periodontitis is defined as the presence of 2 or more interproximal sites with ≥ 6 mm AL (not on the same tooth) and 1 or more interproximal site(s) with ≥ 5 mm PPD. Moderate periodontitis is defined as 2 or more interproximal sites with ≥ 4 mm clinical AL (not on the same tooth) or 2 or more interproximal sites with PPD ≥ 5 mm, also not on the same tooth. Mild periodontitis is defined as ≥ 2 interproximal sites with ≥ 3 mm AL and ≥ 2 interproximal sites with ≥ 4 mm PPD (not on the same tooth) or 1 site with ≥ 5 mm. According to the United States National Health and Nutrition Examination Survey the prevalence of periodontitis in adults aged 30 years and older was 47.2%, representing about 64.7 million adults, distributed as 8.7%, 30.0%, and 8.5% with mild,

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adults aged 65 years and older, 64% had either moderate or severe periodontitis, while with respect to the extent of the disease, 56% and 18% of the adult population had 5% or more periodontal sites with ≥ 3 mm AL and ≥ 4 mm PPD, respectively. According to a recent epidemiological survey, the prevalence of severe and moderate periodontitis in a north Italian adult population (20-75 years) were 34.94% and 40.78% respectively (Aimetti et al. 2015). Authors observed that the prevalence of severe periodontitis increased with age; in the subjects under 30 years it was 6.25% (95% CI: 2.62–14.18) and it increased to 52.63% (95% CI: 45.51–59.65) in the 50–59-year-old group and then levelled off (Aimetti et al. 2015).

Figure 1. Clinical situation of a patient affected by severe periodontitis.

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The aetiology of periodontal diseases is bacteria (Socransky & Haffajee 1994). The human oral cavity harbours a substantial and continuously evolving load of microbial species (Aas et al. 2005). The ecological interactions between the host and microbes determine the severity of the disease and unlike many infectious diseases, periodontitis appears to be an infection mediated by the overgrowth of commensal organisms, rather than by the acquisition of an exogenous pathogen (Moore & Moore 1994). As microorganisms evolve more rapidly than their mammalian hosts, immune mechanisms that determine the ecological balance of commensal organisms also need to change to preserve homeostasis (Gemmell et al. 1997). The pathogenesis of periodontitis is mediated by the inflammatory response to bacteria in the dental biofilm. There is evidence that specific microbes are associated with the progressive forms of the disease; however, the presence of these microorganisms in individuals with no evidence of disease progression suggests that the disease is the net effect of the immune response and the inflammatory processes, not the mere presence of the bacteria; regulation of immune–inflammatory mechanisms governs patient susceptibility and is modified by environmental factors (Seymour 1991, Uitto et al. 2003).

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1.2 Periodontitis, Systemic Inflammation and Systemic Diseases and Conditions

For decades, physicians and dentists have paid close attention to their own respective fields. However in recent years there has been intense interest in potential associations between periodontitis and various chronic systemic diseases and conditions.

Despite the localized nature of periodontitis, infection of the sulcus/ periodontal pocket can lead to inflammatory responses beyond the periodontium. Periodontal bacteria possess a plethora of virulence factors that induce cells to produce inflammatory mediators at the gingival level (Graves et al. 2000), but both bacteria and inflammatory mediators may enter the blood and disseminate systemically having a measurable impact on systemic inflammation (Van Dyke & Van Winkelhoff 2013). The epidemiological evidence linking periodontitis to the progression of systemic diseases, such as atherosclerotic cardiovascular disease and diabetes mellitus, is associated with both bacteremia and elevated levels of various markers of systemic inflammation (Dietrich et al. 2013, Taylor et al. 2013). Indeed, it has been reported that subjects affected by periodontitis present, in comparison with systemically healthy controls, higher plasma concentrations of various markers of systemic inflammation, notably C-reactive protein (CRP), interleuchin-6 (IL-6), fibrinogen and tumor necrosis

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factor-alpha (TNF-α) (Buhlin et al. 2003, Nishimura et al. 2003, Loos 2005, D’Aiuto et al. 2007a, Paraskevas et al. 2008).

Studies produced in the last 20 years indicate that periodontitis exhibit a higher relative risk for aggravating existing diabetes (Borgnakke et al. 2013) due to a deterioration of glucose metabolism and control (Demmer et al. 2010); increases the risk for cardiovascular disease (Janket et al. 2003, Humphrey et al. 2008) due to a higher probability for developing atherosclerosis (Lockhart et al. 2012) probably mediated by systemic inflammatory mediators (Loos 2005, Ioannidou et al. 2006, Paraskevas et al. 2008); and represent a potential risk factor for adverse pregnancy outcomes (Chambrone et al. 2011, Ide & Papapanou 2013). Moreover, the status of long-term low/moderate-intensity systemic inflammation determined by periodontitis, has been associated with overweight and obesity (Keller et al. 2015), erectile dysfunction (Keller et al. 2012, Matsumoto et al. 2014), Alzheimer’s disease (Kaye et al. 2010, Kamer et al. 2012) and obstructive sleep apnea (Keller et al. 2013).

1.3 Non-Surgical Periodontal Treatment

The treatment of periodontitis aims at preventing further disease progression to reduce the risk of tooth loss, minimize symptoms and

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provide information on maintaining a healthy periodontium. As the disease progression was understood to be associated with the amount of plaque or calculus, removal of all tooth supra- and sub-gingival deposits is considered the first step of therapy aiming at the reduction of inflammation and amelioration of clinical periodontal parameters (Badersten et al. 1981, 1984, Hill et al. 1981, Lindhe et al. 1982). The supragingival component of plaque removal consists of meticulous supragingival plaque/calculus removal using hand (scalers) or powered (sonic/ultrasonic) instruments or both. The subgingival part of the procedure is usually divided in three distinct procedures: debridement, scaling, and root planing (Kieser 1994). Debridement is defined as the removal or disruption of the structure of subgingival plaque, and is equivalent to supragingival polishing. Scaling is performed to remove calcified accretions. Root planing aims at removing diseased root cementum through reshaping of the root surface. More specifically, scaling implies the removal of plaque, calculus and stains from a clinical crown and root surface, while root planing consists in the removal of cementum or surface dentin containing calculus or contaminating toxins or microorganisms (American Academy of Periodontology 1993). As for the supragingival instrumentation, also the subgingival one may be performed using sonic/ ultrasonic devices, hand instruments (curettes) (Figure 3) or

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both. Considering the different efficacy of powered and hand instruments in removing subgingival deposits (Oosterwaal et al. 1987, Lea et al. 2004, Oda et al. 2004, Suvan 2005) and in order to guarantee an optimal therapeutic outcome the current non-surgical scaling and root planing (SRP) treatment consists of root debridement with sonic/ultrasonic devices and finishing instrumentation with curettes (Ruppert et al. 2002).

Nowadays, subgingival instrumentation is considered the gold standard of periodontal therapy and its clinical efficacy is well documented in systematic reviews (Van der Weijden & Timmerman 2002, Hallmon & Rees 2003, Smiley et al. 2015). The contemporary delivery modalities of non-surgical periodontal treatment are two; the stage (quadrant or sextant) and the full-mouth approach (FM-SRP). The former consists in 4-6 appointments over a period of 3-6 weeks (Badersten et al. 1981, 1984) while the latter involves scaling and root planing, with/ without use of antimicrobial agents, of the entire dentition within 24 hours in one or two sessions (Quirynen et al. 1995, 2000, Apatzidou & Kinane 2004). Although some studies have reported that with the full-mouth approach the time needed for subgingival instrumentation is shorter per pocket site (3.3 min) in comparison with the staged approach (8.8 min) (Wennström et al. 2005), in terms of effectiveness there is no clear evidence that full-mouth disinfection provides additional

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benefit compared to staged periodontal therapy (Eberhard et al. 2008, 2015, Lang et al. 2008).

Ultimately both approaches may be successful and thus the choice of one or other treatment modality should be based on patient preferences, professional skills, logistic settings and cost-effectiveness.

Figure 3. Curettes for subgingival instrumentation.

1.4 The Impact of Non-Surgical Periodontal Treatment on Systemic Diseases and Conditions

Non-surgical periodontal treatment during the first 24-72 hours post-treatment results in a considerable increase in systemic inflammatory markers such as CRP, fibrinogen, serum-amyloid A, IL-6 and TNF-α (D’Aiuto et al. 2004, Graziani et al. 2010a, 2015), enhancement of coagulative tendency (D’Aiuto et al. 2007b) and reduction of the endothelial function

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(Tonetti et al. 2007). This outcome is likely the results of trauma from the instrumentation and post-operative bacteremia. Nevertheless, at 3-month post-treatment, periodontitis patients show improvement in the atherosclerotic profile as assessed by lower levels of CRP, fibrinogen and total and low-density cholesterol (D’Aiuto et al. 2013, Teeuw et al. 2014). Periodontal treatment also improves the endothelial function (Orlandi et al. 2014) and provides a significant reduction of glycated hemoglobin (Engebretson & Kocher 2013). Furthermore, the non-surgical periodontal treatment seems to decrease the insulin resistance among the obese (Gürgan et al. 2013) and to improve the erectile dysfunction (Eltas et al. 2013).

1.5 Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic destructive inflammatory disease characterized by autoantibodies and the accumulation and persistence of an inflammatory infiltrate in the synovial membrane that leads to synovitis and the destruction of the joint architecture (Scott et al. 2010). RA is actually considered “a clinical syndrome spanning several disease subsets” (van der Helm-van Mil & Huizinga 2008). These diverse subsets entail several inflammatory cascades that finally lead to synovial inflammation and

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characterized by overproduction and overexpression of TNF (Feldmann et al. 1996) which leads to overproduction of IL-6 and other cytokines (Choy et al. 2002). Rheumatoid factor (RF) is the classic autoantibody in RA directed against the fragment crystallisable portion of the immunoglobulin G

molecule. Additional and increasingly important types of antibodies are those directed against citrullinated peptides (ACPAs); ACPAs seem to have a higher specificity than RF for early RA, good predictive validity, high sensitivity, apparent cost-effectivess and good stability and reproducibility (van der Linden et al. 2009).

RA affects approximately 0.5 - 1% of adults in developed countries. Prevalence of RA varies geographically (Costenbader et al. 2008, Biver et al. 2009); the disease is common in northern Europe and North America in comparison with other parts of the world. RA prevalence increases with age and is three times more prevalent in women having a peak incidence of onset in the fourth and fifth decades of life (Sacks et al. 2010) (Figure 4 and Figure 5).

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Figure 4. Clinical situation of hands affected by RA.

Figure 5. Radiologic situation of hands affected by RA.

Currently the triggers that initiate breach of immune tolerance and the subsequent progression to clinically relevant autoimmunity and in particular articular localization leading to the clinical symptoms of RA are unknown. Most likely, there is a combination of genetic, including epigenetics, environmental, hormonal, and infectious co-factors. Overall, genetic factors may account for around 50% of disease risk in RA (Scott et al. 2010), and

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although this has been debated it is generally accepted that environmental factors, like smoking and stress, are crucial (Klareskog et al. 2008).

Diagnosis of RA is based on new classification criteria developed in 2010 by the American College of Rheumatology (ACR) and by the European League Against Rheumatism (EULAR), which assess joint involvement, autoantibody status, and acute-phase response and symptom duration (Aletaha et al. 2010). In the new criteria set, classification as “definite RA” is based on the confirmed presence of synovitis in at least 1 joint, absence of an alternative diagnosis that better explains the synovitis, and achievement of a total score of 6 or greater (of a possible 10) from the individual scores in 4 domains: number and site of involved joints (score range 0–5), serologic abnormality (score range 0–3), elevated acute-phase response (score range 0–1), and symptom duration (2 levels; range 0–1).

The clinical assessment of the disease includes swollen and tender joint counts; standard joint counts focus on 28 joints in hands, upper limbs and knees. Laboratory measures include erythrocyte sedimentation rate (ESR) and CRP. Patient-based measures appraise pain and global assessment; the health assessment questionnaire (HAQ) is based on five patient-centered dimensions: disability, pain, medication effects, costs of care and mortality (Bruce & Fries 2005).There is also available a short or 2-page HAQ. The short

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version contains only the HAQ disability-index (HAQ-DI) together with patient’s global pain visual analog scale (VAS). Overall, it has been the Short or 2-page HAQ or the HAQ-DI that has received the widest attention, most frequent use, and that is most commonly referred to as “the HAQ.” The HAQ-DI includes items that assess fine movements of the upper extremity, locomotor activities of the lower extremity, and activities that involve both the upper and lower extremities. Standard scoring takes into account the use of aids and devices or assistance from another person. There are 20 items in eight categories that represent a comprehensive set of functional activities – dressing, rising, eating, walking, hygiene, reach, grip, and usual activities. The HAQ-DI scale has 25 possible values (i.e., 0, 0.125, 0.250, 0.375 … 3). Scores of 0 to 1 generally represent mild to moderate difficulty, 1 to 2 represent moderate to severe disability, and 2 to 3 indicate severe to very severe disability.

Finally there are combined indices that amalgamate clinical and individual assessments with laboratory values. The disease activity score 28 (DAS28) combines 28 swollen and 28 tender joints (hands, arms, and knees), patient’s global assessment, and erythrocyte sedimentation rate to indicate the patient’s current status. Because calculation of DAS28 entails application of a complex mathematical formula, automatic internet calculators are used in

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the everyday clinical practice (http://www.4s-dawn.com/DAS28/). DAS28 provides a number between 0 and 10 indicating the activity of RA; remission when DAS28 < 2.6, low when 2.6 ≤ DAS28 < 3.2, moderate when 3.2 ≤ DAS28 ≤ 5.1 or high when DAS > 5.2.

Management of RA includes the use of analgesics and non-steroidal anti-inflammatory drugs to reduce pain and articular stiffness. Nevertheless, the core of the RA medical treatment is represented by the disease-modifying antirheumatic drugs (DMARDs). DMARDs are a heterogeneous collection of otherwise unrelated drugs that reduce joint swelling and pain, decrease acute-phase markers, limit progressive joint damage slowing down the disease and improving function (Donahue et al. 2008). Methotrexate is the dominant DMARD; sulfasalazine, hydroxychloroquine and leflunomide are also frequently used. In more recent years, TNF inhibitors and other biological agents (abatacept, rituximab, tocilizumab, certolizumab, adalimumab, infliximab, golimumab) have been introduced constituting the so-called bDMARDs (biologic DMARDs) (Smolen et al. 2007).

Patients with RA, in addition to debilitating joint destruction - potentially interesting the temporomandibular joint (Laurell et al. 1989) - demonstrate substantial co-morbidity, including significantly accelerated atherosclerosis, psychological disease and socioeconomic decline (Sokka et al. 2008, Peters et

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al. 2010). Treatment-associated comorbid disorders include osteopenia/osteoporosis and eye cataract, gastrointestinal ulceration, infections and melanoma.

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2. Objectives of the PhD project

The present PhD project consists of two phases (I phase: epidemiological study and II phase: randomized clinical trial) and thus has two distinctive objectives.

The objective of the I phase was to assess the prevalence of periodontitis in patients with RA and to describe their clinical and serological profile comparing it with a control population affected by RA but not suffering from periodontitis (Figure 6).

The objective of the II phase was to evaluate the possible beneficial additional value of non-surgical periodontal therapy on systemic markers of inflammation and clinical and serological parameters of RA (Figure 6).

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Figure 6. Overall outline of the PhD project Screening* Units of Rheumatology and Dentistry Patients with RA + P** Test group: immediate P treatment Control group: delayed P treatment Patients only with RA

* Screening consisting in Periodontal and Rheumatologic examinations

** Patients with RA presenting generalized severe P

RCT Epidemiological

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3. Rationale of the PhD project

Observations related to oral conditions and inflammatory arthritis extend back for centuries with Hippocrates suggesting that extracting teeth could cure arthritis. In far more recent years, Greenwald & Kirkwood affirmed that “periodontitis and rheumatoid arthritis have much in common; so much so that it has been argued that they are really the same disease” (Greenwald & Kirkwood 1999).

Apparently, although primary etiological differences seem to exist, there is a similarity between the pathologic mechanisms of RA and those of periodontitis. In both diseases, an imbalance between pre-inflammatory (TNF-α, IL-6) and anti-inflammatory cytokines may lead to destruction of connective tissue.

Interestingly, the two pathologies share some risk factors like smoking and stress (Klareskog et al. 2002, Baka et al. 2009, Reynolds 2014), while genetic variations in genes encoding for elements of the innate immune system represent susceptibility factors for both diseases (Bonfil et al. 1999, Laine et al. 2001, Klareskog et al. 2006). Furthermore, both diseases are cumulative; that is, severity and loss of function increase with longer disease duration. Several hypotheses have been proposed for the relationship between RA and periodontitis. Of the numerous hypotheses, two in particular, seem to be

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quite promising. One is referred to as the “two-hit” model, in which a primary “hit” of chronic inflammation via chronic periodontitis followed by a secondary arthritogenic hit to induce RA can lead to an exacerbated inflammatory response (Golub et al. 2006). The second hypothesis advocates that autoimmune responses develop to proteins that are partially altered by either the host inflammatory process or bacterial enzymes (Rosenstein et al. 2004, Wegner et al. 2010).

This association has been supported by the results of animal studies, showing that induction of arthritis in rats suffering from periodontitis resulted in an exacerbation of the articular breakdown (Bartold et al. 2010, Cantley et al. 2011) (Figure 7). Human epidemiological studies have produced contrasting results; numerous studies have supported an association between RA and periodontitis (de Pablo et al. 2008, Pischon et al. 2008, Dissick et al. 2010, Mikuls et al. 2014) while others failed to demonstrate an association between these two pathologies (Joseph et al. 2013, Susanto et al. 2013). Differences in RA criteria and methods for evaluation of periodontal status, however, represent a problem in interpretation of the literature (Nesse et al. 2008, Linden et al. 2013, Susanto et al. 2013).

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RA+ P RA

Animal studies

From Cantley et al. 2011

Figure 7. Animal studies consisting in the induction of RA Versus induction of RA and P. Macroscopic appearance of the paws: (a) Experimental RA; (c) Experimental RA and P

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4. Materials and Methods

4.1 Experimental design and patients’ selection

This was a single-centre epidemiological and randomized controlled clinical trial with a 3-months follow-up. The protocol of the study received approval from the University Hospital of Pisa ethical committee (Pisa, Italy, approval number 88 on 29th_{May 2014) and it was conducted according to the} principles outlined in the Declaration of Helsinki on experimentation involving human subjects.

Eligible study participants were identified among referrals for Periodontitis to the Unit of Dentistry and Oral Surgery of the University Hospital of Pisa (Italy) and among referrals for RA to the Unit of Rheumatology of the University Hospital of Pisa (Italy). All participants gave written informed consent, full medical and dental histories were recorded and oral and rheumatologic examinations were performed. All patients with RA satisfied the 2010 ACR-EULAR classification criteria (Aletaha et al. 2010). Prevalence of periodontitis was reported according to the AAP case definitions for surveillance of periodontitis (Page & Eke 2007, Eke et al. 2012b). Exclusion criteria were (i) age younger than 18 years, (ii) pregnancy, breastfeeding or oral contraceptives, (iii) edentulism, (iv) reported diagnosis of other

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syndromes associated with RA, (v) subjects having changed their RA therapeutic regimen within the 3 months before the beginning of the study and (vi) subjects necessitating antibiotic prophylaxis to undergo periodontal clinical examination and treatment. The candidates for the randomized clinical trial, in addition to the inclusion criteria regarding the epidemiological part, had to present with (i) at least 15 teeth, (ii) generalized severe periodontitis, that is interesting at least 25% of sites and (iii) absence of non-surgical periodontal treatment in the 6 months preceding the beginning of the study.

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4.2 Flow chart of the study

Flowchart

Epidemiological evaluation Group RA Subjects affected only by RA Group RA + P Subjects affected by RA and P CE+HE RCT Test; subjects Immediate P treatment Control; subjects Delayed P treatment HE

Control and OHI Baseline

T24h

T60 T0

CE+HE T30 Control and OHI

CE+HE T90

RA: Rheumatoid Arthritis; P: Periodontitis, CE: Periodontal and Rheumatologic clinical examination; HE: Hematologic examination; RCT: Randomized Clinical Trial; OHI: Oral Hygiene Instructions

4.3 Clinical parameters

At the baseline visit blood samples were collected and subjects undergone periodontal and rheumatologic clinical examinations.

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Smoking history was registered dichotomously as current or never/former and no stratification on cigarettes/day and years of smoking was made. Weight and height were measured and body mass index (BMI) was calculated.

Periodontal clinical parameters

Standard periodontal clinical parameters were assessed using a UNC 15-mm periodontal probe by a masked calibrated examiner at six sites/tooth excluding third molars. Calibration was made on a total of 10 non-study subjects affected by periodontitis. The examiner recorded full-mouth pocket probing depth (PPD) and recessions at six sites per tooth (excluding third molars) on two different occasions using a manual, UNC-15 periodontal probe. Upon completion of all measurements, the intra-examiner repeatability for AL measurement was assessed. The examiner was judged to be reproducible after meeting a percentage of agreement within ± 2 mm between repeated measurements of at least 98% (Graziani et al. 2010b). Full-mouth PPD and recession of the gingival margin (REC) were recorded with measurements rounded to the nearest millimeter. Clinical attachment level was calculated as the sum of PPD and REC. The full-mouth plaque score (FMPS) was measured as the percentage of the total surfaces showing plaque assessed dichotomously on six surfaces per tooth (O’Leary et al.

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1972). Similarly, a full-mouth percentage bleeding score (FMBS) was calculated after assessing dichotomously the presence of bleeding on probing (Ainamo & Bay 1975).

Rheumatologic clinical parameters

For each participant, an expert rheumatologist recorded the number of tender and swollen joints, the patient’s general assessment of his/her condition scored on a visual analog scale (VAS), disease activity score 28 joints (DAS28) and RA medication, including DMARDs or bDMARDs. All subjects filled in the short health assessment questionnaire (HAQ-DI) to measure disability.

4.4 Blood collection and laboratory analysis of the serum markers Serum samples were collected from a venipuncture in the antecubital fossa performed before 9 AM and after a 9-12 hours fast for all patients. All laboratory analyses were performed in the laboratories of the University Hospital of Pisa (Italy). Blood samples were immediately processed by laboratory members masked to the group allocation.

Serum concentrations of CRP and Fibrinogen were measured by immunoturbidometry (Cobas, Roche Diagnostic, Mannheim, Germany). The ESR was determined by the Sediplus® S2100 automatic ESR analyzer

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(Sarstedt Ag&Co, Nümbrecht, Germany). IgM RF (in international units per milliliter) were measured by using an in-house validated ELISA (cutoff point for positivity: 25 U/mL). Total IgG ACPAs (in units per milliliter) were determined by using the Phadia analyzer (Phadia Laboratory Systems, Phadia AB, Uppsala, Sweden) with an upper detection limit of 340 U/mL (cutoff point for positivity: 10 U/mL).

In addition to the abovementioned serum markers, for all subjects participating to the randomized clinical trial the serum levels of IL-6 and TNF-α were analyzed using an enzyme-linked immunosorbent Multiplex Array according to the manufacturer’s instructions (Meso Scale Discovery, Rockville, Maryland, MD, USA).

4.5 Randomized clinical trial (RCT)

Randomization and allocation concealment

Study participant numbers were assigned in ascending order at the enrolment visit. RCT patients were randomly assigned in a 1:1 ratio to either immediate (test group) or delayed (control group), that is performed at the completion of the 3-month follow-up, FM-SRP therapy using a computer generated table. Non-clinical staff members masked to treatment allocation had access to the randomization list. Allocation to treatment was concealed

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to the clinical examiner and statistician with opaque envelopes which were opened by the clinician on the day of treatment.

Non-surgical periodontal treatment

Non-surgical periodontal treatment, consisting in both supra- and sub-gingival mechanical instrumentation of the root surface was performed by a single periodontist. Sub-gingival instrumentation was provided using both hand (curettes) and ultrasonic instrumentation with fine tips (EMS, Nyon, Switzerland). Local anesthesia was used when needed and no time constraints were imposed. After completion of FM-SRP all test group patients received oral hygiene motivation sessions including oral hygiene instructions. During these sessions powered toothbrushing and usage of inter-dental brushing were carefully explained and showed to the subjects. Oral hygiene instructions were re-enforced once a month until the completion of the 3-month follow-up.

Re-assessment examinations

All test group patients undergone full periodontal and rheumatologic clinical re-examinations 90 days after the completion of FM-SRP. Blood collection for the analysis of the serum concentration of CRP, ESR, Fibrinogen, IL-6 and TNF-α was also performed.

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4.6 Statistical analysis

Data analysis was performed using a statistical software package (SPSS for Windows, version 15.0; SPSS Inc., Chicago, IL, USA). Data are presented as mean and standard deviation in case of normal distribution and percentages for categorical data. Shapiro–Wilk test was applied to determine data normality.

Non-parametric correlations analyses between RA clinical and serological indices and periodontal clinical parameters were evaluated with the Spearman rank analyses. In order to calculate the odds ratio (95% confidence interval, CI) for RA patients also affected by periodontitis to present with moderate-severe DAS28 a binary logistic regression was performed; the OR was presented both unadjusted and after adjusting for RA medication, FR, ACPAs, smoking status and gender.

Changes in serum biomarkers and periodontal clinical parameters were analysed with ANOVA for measures between groups at different time-points. Statistical significancewas set at p = 0.05.

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5. Results

5.1 Epidemiological study

Study population and RA clinical and serological characteristics

The final cohort consisted of 92 patients with RA. Fifty subjects, representing 54.3% of the study sample, resulted affected by periodontitis (RA-P group), while the other 45.7% only had RA (RA group). Demographic characteristics as well as information regarding smoking status, BMI, number of teeth and severity of periodontitis are reported in Table 1. Both groups were comparable for age, gender distribution and BMI and consisted of 20% of current smokers. The number of teeth present was statistically lower in the RA-P compared to the RA group (p < 0.05).

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Table 1. Characteristics of the study sample

Variable Patients with P+RA

(n=50)

Patients with RA (n=42)

p value*

Age (years; mean [SD]) 59.3 (11.1) 55 (13.2) 0.095

Gender (female [%]) 43 (86) 35 (83.3) 0.723 BMI (kg/m2_{; mean [SD])} _25.1 _25.5 _0.627 Smoking status (n [%]) Smokers 10 (20) 9 (21.4) 0.866 Non-smokers 40 (80) 33 (78.6) 0.866 Severity of P (n, [%]) Mild 17 (34) Moderate 10 (20) Severe 23 (46)

Number of teeth (n; mean [SD])

21.6 (5.9) 24.2 (6) 0.039

*p-Values refer to between-group differences.

P: Periodontitis; RA: Rheumatoid Arthritis; BMI: body mass index

Rheumatoid Arthritis medication status (DMARDs versus bDMARDs) and RA clinical and serological profiles of both groups are reported in Table 2. DAS28 mean value (± standard deviation, SD) in RA-P group was 3.14 (± 1.1), while the respective value in the RA group was 2.81 (± 1.0); these differences were not statistically significant (p > 0.05). RA severity presented a similar and comparable distribution between the two groups. One third of the subjects of the RA group and half of the subjects of the RA-P group were under treatment with DMARDs, while more than 65% of the RA subjects versus 48% of the RA-P subjects were using bDMARDS (p > 0.05). With regards to RA serological profile (RF and ACPAs), there were statistically more subjects seropositive for ACPAs in the RA group (66.7% versus 42%, p < 0.05) whereas no statistical differences were observed when comparing the seropositivity

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for RF of the two groups. Finally, the concentrations of the serum inflammatory biomarkers (CRP, ESR and Fibrinogen) in the two groups were comparable.

Table 2. RA clinical and serological characteristics of the study sample Variable Patients with P+RA

(n=50) Patients with RA (n=42) p value* RF (positive [%]) 24 (48) 23 (54.8) 0.052 ACPAs (positive [%]) 21 (42) 28 (66.7) 0.012 RA Medication (n [%]) Biologic agents 24 (48) 28 (66.7) 0.072 DMARDs 26 (52) 14 (33.3) RA Severity (n [%]) 0.066 Remission 18 (36) 20 (47.6) Low 9 (18) 13 (31) Moderate 21 (42) 7 (16.7) High 2 (4) 2 (4.8) DAS28 (mean, SD) 3.14 (1.1) 2.81 (1) 0.162 HAQ- DI (mean, SD) 0.63 (0.6) 0.81 (0.6) 0.205 CRP (mg/dl; mean, SD) 2.29 (8.5) 1.08 (2.8) 0.350

ESR (mm/hour; mean, SD) 21 (18.5) 15.7 (14.3) 0.129

Fibrinogen (mg/dl; mean, SD)

353.5 (105.1) 332.8 (119.7) 0.385

VAS pain (mean, SD) 40 (25) 40.9 (26.2) 0.870

DAS28 ≥ 3.2 (n [%]) Negative 27 (54) 31 (73.8) 0.050 Positive 23 (46) 11 (26.2) DAS28 > 5.2 (n[%]) Negative 48 (96) 40 (95.2) 0.858 Positive 2 (4) 2 (4.8)

*p-Values refer to between-group differences.

P: Periodontitis; RA: Rheumatoid Arthritis; RF: Rheumatoid Factor; ACPAs: antibodies anti-citrullinated peptides; DAS-28: Disease activity score 28; HAQ-DI: Health assessment questionnaire Disability index; CRP: C-reactive protein; ESR: erythrocyte sedimentation rate; VAS: visual analog scale

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Correlation of RA activity and periodontal clinical parameters

As demonstrated in Table 3 a significant positive correlation between RA severity and all the periodontal clinical parameters (PPD, FMPS and FMBS) (p < 0.01) was observed.

Table 3. Correlations between RA severity and periodontal clinical parameters (Spearman correlation coefficients)

Periodontal Clinical Parameters RA Severity

N sites PPD ≥ 4 mm 0.895* % sites PPD ≥ 4 mm 0.893* N sites PPD ≥ 5 mm 0.807* % sites PPD ≥ 5 mm 0.806* FMPS (%) 0.475* FMBS (%) 0.428*

RA: Rheumatoid Arthritis; PPD: probing pocket depth; FMPS: full-mouth plaque score; FMBS: full-mouth bleeding score

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Logistic Regression and Odds Ratio (OR)

In Table 4 are reported the unadjusted and adjusted ORs for AR medication, FR, ACPAs, smoking status and gender for subjects affected by periodontitis to present a moderate-severe DAS28 score (DAS28 ≥ 3.2). Patients with periodontitis and RA have an unadjusted OR = 2.4 (95% confidence interval [CI] 0.99 – 5.81) of presenting a moderate-severe DAS28 score (DAS28 ≥ 3.2); after adjusting for RA medication, FR, ACPAs, smoking status and gender the OR resulted 2.62 (95% CI 0.96 – 7.12).

Table 4. Unadjusted and adjusted1 _{odds ratio (OR) and 95% confidence} intervals (95% CI) DAS28 ≥ 3.2 Characteristic Unadjusted OR (95% CI) Adjusted OR 1 (95% CI) Periodontitis 2.40 (0.99 – 5.81) 2.62 (0.96 – 7.12)

1_{binary logistic regression, adjusting for Rheumatoid Arthritis medication; Rheumatoid}

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5.2 Randomized Clinical Trial

Study population and baseline characteristics

Sixteen subjects were included and completed the 3-month follow-up from January 2015 to December 2016. All patients recruited were Caucasians. Both groups were comparable for age, gender distribution (87.5% females), BMI, RA medication, RF and ACPA profile while ¼ of them consisted of current smokers (Table 5).

Table 5. Characteristics of the RCT sample

Variable Test group (n=8) Control group (n=8) Age (years; mean [SD]) 64.3 (7.4) 58.2 (9.5)

Gender (female [%]) 7 (87.5) 7 (87.5) Smoking habits (n [%]) Smokers 2 (25) 2 (25) Non-smokers 6 (75) 6 (75) RA Medication (n [%]) Biologic agents 4 (50) 5 (62.5) DMARDs 4 (50) 3 (37.5) RF (positive [%]) 4 (50) 5 (62.5) ACPAs (positive [%]) 4 (50) 6 (75) BMI (kg/m2_{; mean [SD])} _{24 (4.2)} _{26 (2.6)}

RA: Rheumatoid Arthritis; DMARDs: Disease Modifying Antirheumatic Drugs; RF: Rheumatoid Factor; ACPAs: Anti-citrullinated proteins antibodies, BMI: body mass index

Periodontal clinical parameters

All patients recruited presented with similar periodontal clinical parameters (severe periodontitis). Non-surgical periodontal treatment produced

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significant clinical benefits in terms of standard periodontal parameters (p < 0.05) (Table 6).

Table 6. Mean (SD) of Periodontal parameters at baseline and 3 months

Variable Test group Control group p

value* Mean (SD) Baseline 3 months p value** Baseline 3 months p value** Number of teeth 20 20 0 23 23 0 0.207 N pockets ≥ 4mm 35.8 (24.5) 18.2 (14) 0.004 47.5 (34.4) 41 (16.1) 0.438 0.010 % pockets ≥ 4mm 29.1 (18) 15 (11) 0.002 32.9 (20.6) 29.7 (14.2) 0.568 0.037 N pockets ≥ 5mm 18.1 (15.7) 7.1 (6.2) 0.018 30.8 (31.1) 20 (12.4) 0.257 0.025 % pockets ≥ 5mm 14.6 (11.7) 5.9 (5.2) 0.011 20.6 (18.1) 14.5 (8.6) 0.294 0.034 FMPS (%) 74.5 (33.4) 26 (9.2) 0.002 76.6 (23.7) 66.9 (26.9) 0.152 0.001 FMBS (%) 43.3 (26.8) 11.4 (4.7) 0.007 48.8 (27.1) 45 (25.3) 0.474 0.007

*p-Values refer to between-group differences at 3 months. ** p-Values refer to intra-group differences at 3 months.

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RA clinical parameters and systemic biomarkers

DAS28 mean (± SD) value in test group (immediate treatment) was 3.05 (± 1.1) at pre-treatment and 2.73 (± 1.2) post-treatment, while the respective values in the control group (delayed treatment) were 2.77 (± 1.3) at pre-treatment and 3.29 (± 1.5) post-pre-treatment (Table 7). These changes were not statistically significant (p > 0.05), but a trend of amelioration may be observed among the patients of the test group (Figure 8). The HAQ-DI score measuring patients’ disability resulted statistically reduced in the test group when compared to the control group (Table 7) (p < 0.05).

Baseline and post-treatment serum levels of CRP, ESR, Fibrinogen, IL-6 and TNF-α for all subjects are presented in Table 7. No statistically significant differences between the two groups were observed 3 months after non-surgical periodontal treatment (p > 0.05).

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Table 7. Mean (SD) of RA parameters and inflammatory biomarkers at baseline and 3 months

Variable Test group Control group p value*

Mean (SD) Baseline 3 months p value** Baseline 3 months p value** DAS-28 3.05 (1.1) 2.73 (1.2) 0.107 2.77 (1.3) 3.2 (1.5) 0.001 0.447 HAQ-DI 0.42 (0.3) 0.35 (0.2) 0.430 0.65 (0.3) 0.84 (0.4) 0.040 0.014 CRP, mg/dl 1.56 (2.3) 1.98 (1.7) 0.553 1.37 (2.2) 2.31 (2.6) 0.108 0.772 ESR, mm/hour 23.7 (15) 26.2 (15.7) 0.659 20.8 (15.2) 26 (16.3) 0.205 0.976 Fibrinogen, mg/dl 400.6 (96.6) 330.6 (75.4) 0.064 326 (117.1) 351.1 (118.9) 0.234 0.688 IL-6, pg/ml 4.9 (4.3) 4.5 (3.2) 0.499 6.8 (6.7) 10.1 (8.8) 0.001 0.114 TNF-α, pg/ml 10.5 (13.1) 12.4 (9.2) 0.493 54.7 (120.8) 62.7 (149.4) 0.012 0.373 *p-Values refer to between-group differences at 3 months.

** p-Values refer to intra-group differences at 3 months.

DAS-28: Disease activity score 28; HAQ-DI: Health assessment questionnaire Disability index; CRP: C-reactive protein; ESR: erythrocyte sedimentation rate; IL-6: interleuchin-6, TNF-α: Tumor Necrosis Factor α

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Groups: Test Control Time T0 T90 DAS 28 0.00 1.00 2.00 3.00 4.00 5.00 6.00

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6. Discussion

The objective of the first phase, the epidemiological study, of the present PhD project was to assess the prevalence of periodontitis in patients with RA and to describe their clinical and serological profile comparing it with a control population affected by RA but not suffering from periodontitis.

In the present study, the overall prevalence of periodontitis in RA subjects was not significantly different in comparison with the values observed in important epidemiological surveys (54.3 % versus 47%) (Eke et al. 2012a). Nevertheless, when considering the prevalence of the sole severe periodontitis cases and when comparing this datum with the prevalence of severe periodontitis in general populations the difference was remarkably strong (25% versus 8.5%) (Eke et al. 2012a). This datum is in contrast with the conclusions of a Swedish study by Sjöström et al. affirming that severe periodontal breakdown occurred less frequently among RA-patients (12%) than among RA free controls (16%) (Sjöström et al. 1989). When referring to the prevalence of moderate to severe periodontitis in patients with RA the results of the present study (35.8%) were similar to the one reported in other studies including RA populations (Mercado et al. 2001, Pischon et al. 2008).

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A particularly interesting finding was the statistically significant difference in the number of ACPA seropositive subjects; more ACPA positive patients were indentified in the control group (RA group). This is in contrast with other studies affirming that the incidence of periodontitis was significantly higher in ACPA positive RA patients (Mikuls et al. 2014). Although the role of ACPAs in RA development is still unclear, these auto-antibodies can be present before RA becomes symptomatic (Nielen et al. 2004). Furthermore, it has been demonstrated that independent of smoking status, patients with periodontitis and patients with lung mucosal inflammation (e.g., bronchiectasis) without RA have higher serum ACPA levels compared with healthy controls, although the level is lower than in patients with RA (Lappin et al. 2013, de Pablo et al. 2014, Perry et al. 2014). In the study population of the RA + P group several patients were diagnosed with a seronegative RA, that is a clinical RA negative for both ACPAs and RF. Accumulating evidence suggests that RA “serotypes” represent distinct disease entities that, despite their clinical overlap, diverge in respect of genetic architecture, cellular pathology and even therapeutic responsiveness (Pratt & Isaacs 2014). We may assume that this particular serological profile may interact distinctly with the proinflammatory biomarkers that determine the periodontal and

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rheumatologic breakdowns; at this purpose further investigations are undoubtedly necessary.

With regards to serum biomarkers no statistically significant differences were observed between the two groups. This datum is not in accordance with other studies reporting higher TNF-α, IL-6, ESR and CRP serum levels in subjects affected both by periodontitis and RA (Nilsson & Kopp 2008, Susanto et al. 2013). The lack of higher serum values for the abovementioned biomarkers in subjects with both RA and periodontitis may be explained by the impact of routine RA medications (Forster & McConley 1986). In fact, all subjects participating in the present study were using either DMARDs or bDMARDS in association with corticosteroids or nonsteroidal anti-inflammatory drugs that reduce the inflammatory component and the intensity of RA by inhibiting proinflammatory proteins such as IL-6, TNF-α and cyclooxygenase 2 (Nowak et al. 1999, Conn 2001, Smolen et al. 2016). Despite the paucity of differences in terms of clinical and serological rheumatologic parameters between the two study groups, a strong positive correlation was observed between RA severity and all clinical periodontal parameters. Furthermore, subjects affected by periodontitis had an OR of 2.62 (95% CI 0.96 – 7.12) to present with moderate-high RA disease activity (DAS28 ≥ 3.2).

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The objective of the II phase, the randomized clinical trial, of the present PhD project was to evaluate the possible beneficial additional value of non-surgical periodontal therapy on systemic markers of inflammation and clinical and serological parameters of RA.

In the present study, the periodontal clinical parameters (FMPS, FMBS and PPD) showed significant improvements at 3 months after periodontal therapy. These results are consistent with other studies reported by Al-Katma et al. (Al-Al-Katma et al. 2007), Ribeiro et al. (Ribeiro et al. 2005), Okada et al. (Okada et al. 2013) and Pinho et al. (Pinho et al. 2009). In contrast to the present study findings, Al-Katma et al. (Al-Katma et al. 2007), Ortiz et al. (Ortiz et al. 2009) and Okada et al. (Okada et al. 2013) reported a reduction in DAS28 scores in patients with RA after non-surgical periodontal treatment. Nevertheless, when the 3 aforementioned articles were combined in a meta-analysis (Kaur et al. 2014) it was no longer possible to appreciate a statistically significant DAS28 reduction. In that case, the authors affirmed that, as for the present study, only a trend towards an ameliorated DAS28 score after non-surgical periodontal treatment could be observed. Interestingly, in the present study, besides the positive DAS28 trend the test group patients reported a statistically significant amelioration

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of their everyday manual and motor activities that more frequently result compromised by the RA (HAQ-DI questionnaire).

The ESR and CRP values did not differ between the RA-P and RA groups, and did not change following periodontal therapy. All patients with RA in the present study were using corticosteroids and DMARds or bDMARDs regularly while systemic treatment duration was rather long (mean duration of drug usage: 10 years for RA-P; 8 years for RA; data not shown). The baseline values of the abovementioned systemic parameters suggest that the included patients with RA were well controlled. Although Ribeiro et al. (Ribeiro et al. 2005) and Al-Katma et al. (Al-Katma et al. 2007) reported significant reductions in the ESR values after non-surgical periodontal therapy, Ortiz et al. (Ortiz et al. 2009), Pinho et al. (Pinho et al. 2009) and Kurgan et al. (Kurgan et al. 2016) reported insignificant reductions in ESR values. Similarly, Okada et al. (Okada et al. 2013), Pinho et al. (Pinho et al. 2009) and Kurgan et al. (Kurgan et al. 2016) did not demonstrate significant reductions in the CRP levels after treatment, while Biyikoglu et al. (Biyikoglu et al. 2013) demonstrated a significant amelioration in serum CRP levels post-treament. A recent systematic review and meta-analysis concluded that non-surgical periodontal treatment in patients with RA and periodontitis could result in reductions of ESR, without a significant effect

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on the CRP levels (Kaur et al. 2014). This is in contrast to other studies that have demonstrated clear reductions in CRP levels in non-RA periodontitis patients following non-surgical periodontal treatment (Paraskevas et al. 2008). The lack of effect observed in RA subjects may be due to the small sample size used in the studies or the masking of a beneficial effect due to the use of DMARDs, leading to a well controlled RA disease activity state (Forster & McConley 1986).

With regards to proinflammatory cytokine TNF-α, no reduction in serum concentrations was observed for our study. In scientific literature, only two studies have previously reported TNF-α levels following non-surgical periodontal treatment (Ortiz et al. 2009, Okada et al. 2013) and only one of them reported a statistically significant decrease in RA patients undergoing non-surgical periodontal treatment (Ortiz et al. 2009). The discrepancy between our study and the studies that reported systemic improvements after periodontal therapy may be explained by the rheumatologic clinical characteristics of the participants (baseline DAS28 scores, type and duration of RA medication), as well as the definition and the severity of periodontitis used by these authors.

IL-6 is also elevated in patients suffering from both RA and periodontitis. As for TNF-α, anti-IL-6 antibodies are used as a biological therapy in the

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management of RA (Nishimoto et al. 2000). Among the patients of the test group a reduction, not statistically significant, was observed. Our findings are in accordance with the data of the only other study available in the literature reporting a not significant decrease in IL-6 levels in subjects who received non-surgical periodontal treatment (Okada et al. 2013).

Undoubtedly, the small sample size of the present RCT, as well as the relatively short follow-up period represent the limitations of the present PhD project and both should be addressed in future RCTs to better elucidate if there is a beneficial effect, in terms of clinical and serological RA parameters, after non-surgical periodontal treatment.

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7. Conclusion

The overall prevalence of periodontitis in a RA population is coherent with the percentages reported in general populations. However, among RA subjects a considerably higher prevalence of severe periodontis has been observed. Furthermore, the clinical severity of RA appears to be strongly correlated with the clinical periodontal parameters and RA subjects also affected by periodontitis seem to have an OR of 2.62 for presenting with a moderate-severe RA (DAS28 score ≥ 3.2).

The non-surgical periodontal treatment appears to determine a trend for amelioration of DAS28 scores among RA patients with periodontitis without determining a statistically significant change in their serological profile. This trend is further appreciated by the subjects as in a self-administered questionnaire (HAQ-DI) the patients undergoing non-surgical periodontal treatment reported a mild amelioration in the execution of their everyday activities. A larger study sample with a longer follow-up period is needed in order to better elucidate the effects of non-surgical periodontal treatment on the clinical and serological parameters of patients affected by rheumatoid arthritis.

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8. References

Aas, J. a, Paster, B.J., Stokes, L.N., Olsen, I. & Dewhirst, F.E. (2005) Defining the Normal Bacterial Flora of the Oral Cavity Defining the Normal Bacterial Flora of the Oral Cavity.

Journal of Clinical Microbiology 43, 5721–5732.

Aimetti, M., Perotto, S., Castiglione, A., Mariani, G.M., Ferrarotti, F. & Romano, F. (2015) Prevalence of periodontitis in an adult population from an urban area in North Italy: Findings from a cross-sectional population-based epidemiological survey. Journal of

Clinical Periodontology 42, 622–631.

Ainamo, J. & Bay, I. (1975) Problems and proposals for recording gingivitis and plaque.

International Dental Journal 25, 229–235.

Al-Katma, M., Bissada, N.F., Bordeaux, J., Sue, J. & Askari, A. (2007) Control of periodontal infection reduces the severity of active rheumatoid arthritis. Journal of clinical

Rheumatology 13, 134–137.

Aletaha, D., Neogi, T., Silman, A.J., Funovits, J., Felson, D.T., Bingham, C.O., Birnbaum, N.S., Burmester, G.R., Bykerk, V.P., Cohen, M.D., Combe, B., Costenbader, K.H., Dougados, M., Emery, P., Ferraccioli, G., Hazes, J.M.W., Hobbs, K., Huizinga, T.W.J., Kavanaugh, A., Kay, J., Kvien, T.K., Laing, T., Mease, P., Ménard, H.A., Moreland, L.W., Naden, R.L., Pincus, T., Smolen, J.S., Stanislawska-Biernat, E., Symmons, D., Tak, P.P., Upchurch, K.S., Vencovský, J., Wolfe, F. & Hawker, G. (2010) 2010 Rheumatoid arthritis classification criteria: An American College of Rheumatology/European League Against Rheumatism collaborative initiative. Arthritis and Rheumatism 62, 2569–2581.

(54)

American Academy of Periodontology.

Apatzidou, D.A. & Kinane, D.F. (2004) Quadrant root planing versus same-day full-mouth root planing: III. Dynamics of the immune response. Journal of Clinical Periodontology

31, 152–159.

Badersten, A., Nilvéus, R. & Egelberg, J. (1981) Effect of non-surgical periodontal therapy.

Journal of Clinial Periodontology, 190–200.

Badersten, A., Nilvéus, R. & Egelberg, J. (1984) Effect of non surgical periodontal therapy II. Severely advenced periodontitis. Journal of Clinical Periodontology 11, 63–76.

Baka, Z., Buzas, E. & Nagy, G. (2009) Rheumatoid arthritis and smoking: putting the pieces together. Arthritis Research and Therapy 11, 238.

Bartold, P.M., Marino, V., Cantley, M. & Haynes, D.R. (2010) Effect of Porphyromonas gingivalis-induced inflammation on the development of rheumatoid arthritis. Journal of

Biver, E., Beague, V., Verloop, D., Mollet, D., Lajugie, D., Baudens, G., Neirinck, P. & Flipo, R. (2009) Low and stable prevalence of rheumatoid arthritis in northern France. Joint Bone

Spine 76, 497–500.

Biyikoglu, B., Buduneli, N., Aksu, K., Nalbantsoy, A., Lappin, D.F., Evrenosoglu, E. & Kinane, D.F. (2013) Periodontal therapy in chronic periodontitis lowers gingival crevicular fluid interleukin- 1beta and DAS28 in rheumatoid arthritis patients. Rheumatology

International 33, 2607–2616.

(55)

(1999) A ‘case control’ study on the rôle of HLA DR4 in severe periodontitis and rapidly progressive periodontitis Identification of types and subtypes using molecular biology (PCR.SSO). Journal of Clinical Periodontology 26, 77–84.

Borgnakke, W.S., Ylöstalo, P. V., Taylor, G.W. & Genco, R.J. (2013) Effect of periodontal disease on diabetes: Systematic review of epidemiologic observational evidence.

Journal of Clinical Periodontology 40.

Bruce, B. & Fries, J.F. (2005) The Health Assessment Questionnaire (HAQ). Clinical and

Experimental Rheumatology 23, S14-18.

Buhlin, K., Gustafsson, A., Pockley, A., Frostegard, J. & Klinge, B. (2003) Risk factors for cardiovascular disease in patients with periodontitis. European Heart Journal 24, 2099– 2107.

Cantley, M.D., Haynes, D.R., Marino, V. & Bartold, P.M. (2011) Pre-existing periodontitis exacerbates experimental arthritis in a mouse model. Journal of Clinical Periodontology

38, 532–541.

Chambrone, L., Pannuti, C.M., Guglielmetti, M.R. & Chambrone, L.A. (2011) Evidence grade associating periodontitis with preterm birth and/or low birth weight: II. A systematic review of randomized trials evaluating the effects of periodontal treatment. Journal of

Choy, E.H.S., Isenberg, D.A., Garrood, T., Farrow, S., Ioannou, Y., Bird, H., Cheung, N.,

Williams, B., Hazleman, B., Price, R., Yoshizaki, K., Nishimoto, N., Kishimoto, T. & Panayi, G.S. (2002) Therapeutic benefit of blocking interleukin-6 activity with an

(56)

anti-double-blind, placebo-controlled, dose-escalation trial. Arthritis and Rheumatism 46, 3143–3150.

Conn, D. (2001) Resolved: Low-dose prednisone is indicated as a standard treatment in patients with rheumatoid arthritis. Arthritis and Rheumatism 45, 462–467.

Costenbader, K., Chang, S., Laden, F., Puett, R. & Karlson, E. (2008) Geographic variation in rheumatoid arthritis incidence among women in the United States. Archives of Internal

Medicine 168, 1664–1670.

D’Aiuto, F., Orlandi, M. & Gunsolley, J.C. (2013) Evidence that periodontal treatment improves biomarkers and CVD outcomes. Journal of Clinical Periodontology 40.

D’Aiuto, F., Parkar, M., Andreou, G., Suvan, J., Brett, P.M., Ready, D. & Tonetti, M.S. (2004) Periodontitis and systemic inflammation: control of the local infection is associated with a reduction in serum inflammatory markers. Journal of dental research 83, 156–160.

D’Aiuto, F., Parkar, M. & Tonetti, M.S. (2007a) Acute effects of periodontal therapy on bio-markers of vascular health. Journal of Clinical Periodontology 34, 124–129.

D’Aiuto, F., Parkar, M. & Tonetti, M.S. (2007b) Acute effects of periodontal therapy on bio-markers of vascular health. Journal of clinical periodontology 34, 124–129.

Demmer, R.T., Desvarieux, M., Holtfreter, B., Jacobs, D.R.J., Wallaschofski, H., Nauck, M., Volzke, H. & Kocher, T. (2010) Periodontal status and A1C change: longitudinal results from the study of health in Pomerania (SHIP). Diabetes care 33, 1037–1043.

Dietrich, T., Sharma, P., Walter, C., Weston, P. & Beck, J. (2013) The epidemiological evidence behind the association between periodontitis and incident atherosclerotic

(57)

cardiovascular disease. Journal of Clinical Periodontology 40, 70–84.

Dissick, A., Redman, R.S., Jones, M., Rangan, B. V., Reimold, A., Griffiths, G.R., Mikuls, T.R., Amdur, R.L., Richards, J.S. & Kerr, G.S. (2010) Association of Periodontitis With Rheumatoid Arthritis: A Pilot Study. Journal of Periodontology 81, 223–230.

Donahue, K., Gartlehner, G., Jonas, D., Lux, L., Thieda, P., Jonas, B., Hansen, R., Morgan, L. & Lohr, K. (2008) Systematic review: comparative eff ectiveness and harms of disease-modifying medications for rheumatoid arthritis. Annals of Internal Medicine 148, 124– 134.

Van Dyke, T.E. & Van Winkelhoff, A.J. (2013) Infection and inflammatory mechanisms.

Journal of Clinical Periodontology 40, S1–S7.

Eberhard, J., Jepsen, S., Jervøe-Storm, P.M., Needleman, I. & Worthington, H. V. (2015) Full-mouth treatment modalities (within 24 hours) for chronic periodontitis in adults (Review). The Cochrane database of systematic reviews 4, CD004622.

Eberhard, J., Jervøe-Storm, P.M., Needleman, I., Worthington, H. & Jepsen, S. (2008) Full-mouth treatment concepts for chronic periodontitis: A systematic review. Journal of

Eke, P.I., Dye, B.A., Wei, L., Thornton-Evans, G.O. & Genco, R.J. (2012a) Prevalence of Periodontitis in Adults in the United States: 2009 and 2010. Journal of dental research

91, 914–920.

Eke, P.I., Page, R.C., Wei, L., Thornton-Evans, G. & Genco, R.J. (2012b) Update of the Case Definitions for Population-Based Surveillance of Periodontitis. Journal of Periodontology

(58)

Eltas, A., Oguz, F., Uslu, M.O. & Akdemir, E. (2013) The effect of periodontal treatment in improving erectile dysfunction: A randomized controlled trial. Journal of Clinical

Periodontology 40, 148–154.

Engebretson, S. & Kocher, T. (2013) Evidence that periodontal treatment improves diabetes outcomes: A systematic review and meta-analysis. Journal of Clinical Periodontology 40, S153–S163.

Feldmann, M., Brennan, F.M. & Maini, R. (1996) Rheumatoid arthritis. Cell 85, 301–310.

Forster, P. & McConley, B. (1986) The effect of antirheumatic drugs on circulating immune complexes in rheumatoid arthritis. QJM: An International Journal of Medicine 58, 29– 42.

Gemmell, E., Marshall, R. & Seymour, G.J. (1997) Cytokines and prostaglandins in immune homeostasis and tissue destruction in periodontal disease. Periodontology 2000, 112– 143.

Golub, L., Payne, J., Reinhardt, R. & Nieman, G. (2006) Can systemic diseases co-induce (not just exacerbate) periodontitis?A hypothetical ‘two-hit’ model. Journal of Dental

Research 85, 102–105.

Graves, D., Jiang, Y. & Genco, C. (2000) Periodontal disease: bacterial virulence factors, host response and impact on systemic health. Current Opinion in Infectious Diseases 13, 227–232.

Graziani, F., Cei, S., La Ferla, F., Vano, M., Gabriele, M. & Tonetti, M. (2010a) Effects of non-surgical periodontal therapy on the glomerular filtration rate of the kidney: an