Antibiotic resistance in the microbiota of periodontitis patients: an update of current findings

Systemic antibiotics are an effective adjunct in the treatment of periodontitis, but their judicious use is necessary as antimicrobial resistance is a growing global concern. This review aims to explore the current understanding and insight related to antibiotic resistance in the subgingival microbiota of periodontitis patients. A search of MEDLINE (PubMed) was carried out from 1 January 2012 to 25 November 2021 for studies related to antibiotic resistance in periodontitis patients. Of the 90 articles identified, 12 studies were selected for inclusion. A significant incidence of antibiotic resistant isolates was reported for Porphyromonas gingivalis, Prevotella intermedia, Prevotella denticola, Prevotella melaninogenica, Fusobacterium nucleatum, Tanerella forsythia, Aggretibacter actinomycetemcomitans, Streptococcus constellatus, Streptococcus intermedius, and Parvimonas micra, but resistance to specific antibiotics did not reach above 10% of isolates in most studies except for amoxicillin resistance in Aggretibacter actinomycetemcomitans. The highest frequency of resistance across all bacterial species was for amoxicillin, clindamycin, and metronidazole. However, resistance patterns were widely variable across geographical locations, and the high heterogeneity between antibiotic-resistant isolates across studies precludes any clinical recommendations from this study. Although antibiotic resistance has yet to reach critical levels in periodontitis patients, an emphasis on antibiotic stewardship interventions such as point-of-care diagnostics and education for key stakeholders is needed to curb a growing problem.

Metronidazole may display anti-inflammatory features in periodontitis treatment: A scoping review

AIM

Metronidazole (MTZ) is an antimicrobial agent used to treat anaerobic infections. It has been hypothesized that MTZ may also have anti-inflammatory properties, but the evidence is limited and has not been previously reviewed. Thus, this scoping review aimed to answer the following question: "What is the evidence supporting anti-inflammatory properties of metronidazole that are not mediated by its antimicrobial effects?"

METHODS

A scoping review was conducted according to the PRISMA-ScR statement. Five databases were searched up to January 2023 for studies evaluating the anti-inflammatory properties of MTZ used as monotherapy for treating infectious and inflammatory diseases.

RESULTS

A total of 719 records were identified, and 27 studies (21 in vivo and 6 in vitro) were included. The studies reported experimental evidence of MTZ anti-inflammatory effects on (1) innate immunity (barrier permeability, leukocyte adhesion, immune cell populations), (2) acquired immunity (lymphocyte proliferation, T-cell function, cytokine profile), and (3) wound healing/resolution of inflammation.

CONCLUSION

Taken together, this scoping review supported a potential anti-inflammatory effect of MTZ in periodontitis treatment. We recommend that future clinical studies should be conducted to evaluate specific MTZ anti-inflammatory pathways in the treatment of periodontitis.

Effects of amoxicillin and metronidazole as an adjunct to scaling and root planing on glycemic control in patients with periodontitis and type 2 diabetes: A short-term randomized controlled trial

OBJECTIVE

To assess the effects of amoxicillin and metronidazole with scaling and root planing (SRP) on periodontal parameters and glycemic control in patients with severe periodontitis and diabetes mellitus.

BACKGROUND

Adjunctive antibiotics use is advantageous for treating periodontitis in patients with severe periodontitis and diabetes. However, the effects of adjunctive antibiotic use on hemoglobin A1c (HbA1c) levels remain unclear.

METHODS

This short-term, randomized controlled trial enrolled patients with severe periodontitis and type 2 diabetes. The patients were randomly allocated to SPR only (i.e., control) or SPR + antibiotics (500 mg of amoxicillin and 200 mg of metronidazole, three times daily for 7 days) groups. Periodontal and hematological parameters were assessed at baseline and 3 months after treatment. Inter- and intra-group analyses were performed using Student's t-tests, Mann-Whitney U tests, and the binary logistic regression models. p-values of <.05 were considered statistically significant.

RESULTS

This study enrolled 49 patients, with 23 and 26 patients in the SRP-only and SRP + antibiotics groups, respectively. The periodontal parameters improved significantly and similarly in both groups after treatment (p < .05). The SRP + antibiotics group had more sites of improvement than the SRP-only group when the initial probing depth was >6 mm. (698 [78.96%] vs. 545 [73.35%], p = .008). The HbA1c levels decreased in the SRP-only and SRP + antibiotics groups after treatment (0.39% and 0.53%, respectively). The multivariable binary logistic regression model demonstrated that antibiotics administration and a high baseline HbA1c level were associated with a greater reduction in the HbA1c level (odds ratio = 4.551, 95% confidence interval: 1.012-20.463; odds ratio = 7.162, 95% confidence interval: 1.359-37.753, respectively).

CONCLUSIONS

SRP and SRP plus systemic antibiotics were beneficial for glycemic control. Adjunctive antibiotic use slightly improved the outcome for patients with severe periodontitis and poorly controlled diabetes.

Comparative Study of Azithromycin Versus Doxycycline Effect on the Resistin Level in Periodontitis Patients With Type 2 Diabetes: A Randomized Controlled Clinical Trial

AIM

The present study aimed to determine if azithromycin (AZM) and doxycycline therapy, as an adjunct to scaling and root planning (SRP), modulate host response and improve clinical outcomes in periodontitis patients with type 2 diabetes mellitus (T2DM).

PATIENTS AND METHODS

Forty-five periodontal sites in 15 periodontitis patients with T2DM received nonsurgical periodontal therapy (NSPT). In Group I, patients were placebo (not receiving any medication), Group II patients received systemic AZM therapy (AZM 250 mg/day for five days), and Group III patients received doxycycline (20 mg twice per day for three months. The resistin level was collected and measured by enzyme-linked immunosorbent assay (ELISA). Gingival index (GI), probing depth (PD), and clinical attachment level (CAL) were recorded at baseline, one-month, and three-month intervals.

RESULTS

All groups showed improvement in clinical parameters and resistin levels throughout the study. The mean resistin level at three months was the highest in Group I and the lowest in Group III. Patients in Group II showed a larger decrease in mean PD than those in Group I and III. Group III had the highest gain in mean CAL, with an increase of 1.78 mm in attachment.

CONCLUSION

Resistin might be a useful indicator of current disease status. In addition, benefits from adjunctive systemic use of AZM and doxycycline have been administered with non-surgical periodontal therapy.

Mycobacterium tuberculosis: A New Hitchhiker in the Etiopathogenesis of Periodontitis

Periodontitis, a chronic inflammatory disease of the gums affects both the ligament and alveolar bone. Severe form of periodontal disease affects a strikingly high number of one billion adults globally. The disease permutes both the soft and hard tissues of the oral cavity leading to localized and systemic diseases. Periodontitis has a deleterious impact on systemic health causing diabetes, cardiovascular diseases, and other disease. The cause of enhanced inflammatory process is due to dysbiosis and an unregulated immune response. Innate immune response and T cells trigger uninhibited cytokine release causing an unwarranted inflammatory response. The RANK- RANKL interaction between osteoblasts, immune cells and progenitor osteoclasts results in maturation of osteoclasts which promote bone resorption. It is well established that dysbiosis of the oral cavity has been implicated in periodontitis. But emerging reports suggest that pulmonary pathogen, Mycobacterium tuberculosis (Mtb), causes extra-pulmonary diseases such as periodontitis. Many clinical case reports advocate the involvement of Mtb in periodontitis which poses a threat with the surge of tuberculosis in HIV and other immunocompromised individuals. Fostering a better understanding of the mechanism, causative agents and control on inflammatory response is imperative in prevention and treatment of periodontitis.

Adjunctive systemic antibiotic effect on periodontal state, salivary enzyme activity, and glycemia imbalance in type-2 diabetics after non-surgical periodontal management

AIM

The current study aimed at analyzing the effect of non-surgical periodontal treatment accompanied by systemic antibiotics on salivary enzyme activities, periodontal parameters, and glycemic control in type-2 diabetic (T2D) patients with chronic periodontitis.

METHODS

The study included 125 type-2 diabetic patients with chronic periodontitis who had good glycemic control (T2Dc), 125 type-2 diabetics who had bad glycemic control (T2Dpc). The 125 T2Dpc were divided randomly into two groups. The first one enrolled 63 T2Dpc and received a non-surgical periodontal treatment (T2Dpc + NST). The second group enrolled 62 T2Dpc and received the non-surgical treatment accompanied by systemic antibiotics (T2Dpc+NST+A). HbA1c, periodontal indices, and salivary enzyme activities were assessed for all groups. The Glycated hemoglobin (HbA1c) was assessed. The Salivary alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransaminase (ALT), lactate dehydrogenase (LDH), and creatine kinase (CK) activities were measured.

RESULTS

The T2Dpc were characterized by the highest probing depth (PPD) and clinical attachment loss (CAL) periodontal scores, as well as ALP, AST, and ALT enzymatic activities. However, BOP did not differ significantly between T2Dc and T2Dpc. Whereas the rest of clinical parameters PI, GI, and OHI-S did not significantly differ between groups. The Pearson's analysis revealed three correlations between ALP-PPD, ALP-CAL, and ALP-BOP (bleeding on probing) in both T2Dc and T2Dpc (P < 0.05). Interestingly, a significant decrease in periodontal indices, salivary enzyme activities, and HbA1c was recorded in T2Dpc+NST+A group.

CONCLUSION

The increase in ALP, AST, and ALT activities reflects the impact of uncontrolled T2D on periodontal tissue alteration. The ALP activity increase was associated with the severity of periodontal status in diabetic patients. In comparison to non-surgical treatment alone, the adjunct use of systemic antibiotics improves periodontal state, enzyme activity, and glycemic control.

Patients with type 2 diabetes and severe periodontitis harbor a less pathogenic subgingival biofilm than normoglycemic individuals with severe periodontitis

BACKGROUND

Whether, and to what extent, diabetes mellitus (DM) can affect the subgingival biofilm composition remains controversial. Thus, the aim of this study was to compare the composition of the subgingival microbiota of non-diabetic and type 2 diabetic patients with periodontitis using 40 "biomarker bacterial species."

METHODS

Biofilm samples of shallow (probing depth [PD] and clinical attachment level [CAL] ≤3 mm without bleeding) and deep sites (PD and CAL ≥5 mm with bleeding) of patients with or without type 2 DM were evaluated for levels/proportions of 40 bacterial species by checkerboard DNA-DNA hybridization.

RESULTS

A total of 828 subgingival biofilm samples from 207 patients with periodontitis (118 normoglycemic and 89 with type 2 DM) were analyzed. The levels of most of the bacterial species evaluated were reduced in the diabetic compared with the normoglycemic group, both in shallow and in deep sites. The shallow and deep sites of patients with type 2 DM presented higher proportions of Actinomyces species, purple and green complexes, and lower proportions of red complex pathogens than those of normoglycemic patients (P < 0.05).

CONCLUSIONS

Patients with type 2 DM have a less dysbiotic subgingival microbial profile than normoglycemic patients, including lower levels/proportions of pathogens and higher levels/proportions of host-compatible species. Thus, type 2 diabetic patients seem to require less remarkable changes in biofilm composition than non-diabetic patients to develop the same pattern of periodontitis.

Clinical benefits of systemic amoxicillin/metronidazole may depend on periodontitis stage and grade: An exploratory sub-analysis of the ABPARO trial

AIM

Assessment of treatment response after systemic amoxicillin/metronidazole adjunctive to subgingival instrumentation (SI) according to stages and grades of the 2018 classification of periodontal diseases.

MATERIALS AND METHODS

We carried out exploratory re-analysis of the placebo-controlled, multi-centre ABPARO trial (52; 45/60 years of age; 205 males, 114 active smokers). Patients were randomized to SI with systemic amoxicillin 500 mg/metronidazole 400 mg (three times a day for 7 days, n = 205; ANTI) or placebo (n = 200; PLAC) and maintenance therapy every 3 months. Patients were reclassified according to the 2018 classification (stage/extent/grade). Treatment effect was the percentage of sites per patient with new attachment loss ≥1.3 mm (PSAL ≥ 1.3 mm) at 27.5 months post-baseline/randomization.

RESULTS

All patients were assigned according to the stage (n = 49 localized stage III, n = 206 generalized stage III, n = 150 stage IV). Because of missing radiographs, only 222 patients were assigned to grades (n = 73 B, n = 149 C). Treatment (PLAC/ANTI) resulted in PSAL ≥ 1.3 mm (median; lower/upper quartile) in localized stage III (PLAC: 5.7; 3.3/8.4% vs. ANTI: 4.9; 3.0/8.3%; p = .749), generalized stage III (8.0; 4.5/14.3% vs. 4.7; 2.4/9.0%; p < .001), stage IV (8.5; 5.1/14.4% vs. 5.7; 3.3/10.6%; p = .008), grade B (4.4; 2.4/6.7% vs. 3.6; 1.9/4.7%; p = .151) and grade C (9.4; 5.3/14.3% vs. 4.8; 2.5/9.4%; p < .001).

CONCLUSIONS

In generalized periodontitis stage III/grade C, a clinically relevant lower percentage of disease progression after adjunctive systemic amoxicillin/metronidazole was observed compared to placebo (PLAC: 9.7; 5.8/14.3% vs. ANTI: 4.7; 2.4/9.0%; p < .001).

Long-term changes in the subgingival microbiota in patients with stage III-IV periodontitis treated by mechanical therapy and adjunctive systemic antibiotics: A secondary analysis of a randomized controlled trial

AIM

To explore whether adjunctive antibiotics can relevantly influence long-term microbiota changes in stage III-IV periodontitis patients.

MATERIALS AND METHODS

This is a secondary analysis of a randomized clinical trial on periodontal therapy with adjunctive 500 mg amoxicillin and 400 mg metronidazole or placebo thrice daily for 7 days. Subgingival plaque samples were taken before and 2, 8, 14 and 26 months after mechanical therapy. The V4-hypervariable region of the 16S rRNA gene was sequenced with Illumina MiSeq 250 base pair paired-end reads. Changes at the ribosomal sequence variant (RSV) level, diversity and subgingival-microbial dysbiosis index (SMDI) were explored with a negative binomial regression model and non-parametric tests.

RESULTS

Overall, 50.2% of all raw reads summed up to 72 RSVs (3.0%) that were generated from 163 stage III-IV periodontitis patients. Of those, 16 RSVs, including Porphyromonas gingivalis, Tannerella forsythia and Aggregatibacter actinomycetemcomitans, changed significantly over 26 months because of adjunctive systemic antibiotics. SMDI decreased significantly more in the antibiotic group at all timepoints, whereas the 2-month differences in alpha and beta diversity between groups were not significant at 8 and 14 months, respectively.

CONCLUSIONS

Mechanical periodontal therapy with adjunctive antibiotics induced a relevant and long-term sustainable change towards an oral microbiome more associated with oral health.

Newly identified pathogens in periodontitis: evidence from an association and an elimination study

We assessed the level of evidence for the presence of new periodontal pathogens by (i) comparing the occurrence of non-classical periodontal taxa between healthy vs. periodontitis patients (Association study); (ii) assessing the modifications in the prevalence and levels of these species after treatments (Elimination study). In the Association study, we compared the prevalence and levels of 39 novel bacterial species between periodontally healthy and periodontitis patients. In the Elimination study, we analyzed samples from periodontitis patients assigned to receive scaling and root planing alone or with metronidazole+ amoxicillin TID/ 14 days. Levels of 79 bacterial species (39 novel and 40 classic) were assessed at baseline, 3 and 12 months post-therapy. All samples were analyzed using Checkerboard DNA-DNA hybridization. Out of the 39 novel species evaluated, eight were categorized as having strong and four as having moderate association with periodontitis. Our findings suggest strong evidence supporting Lancefieldella rimae, Cronobacter sakazakii, Pluralibacter gergoviae, Enterococcus faecalis, Eubacterium limosum, Filifactor alocis, Haemophilus influenzae, and Staphylococcus warneri, and moderate evidence supporting Escherichia coli, Fusobacterium necrophorum, Spiroplasma ixodetis, and Staphylococcus aureus as periodontal pathogens. These findings contribute to a better understanding of the etiology of periodontitis and may guide future diagnostic and interventional studies.

Systemic Antibiotics and Chlorhexidine Associated with Periodontal Therapy: Microbiological Effect on Intraoral Surfaces and Saliva

The effect of systemic antibiotics on the microbial profile of extracrevicular sites after periodontal treatment is currently the subject of research. This study evaluated the microbiological effects on different oral cavity sites of scaling and root planing (SRP) combined with antimicrobial chemical control in the treatment of periodontitis. Sixty subjects were randomly assigned to receive SRP alone or combined with metronidazole (MTZ) + amoxicillin (AMX) for 14 days, with or without chlorhexidine mouth rinse (CHX) for 60 days. Microbiological samples were evaluated by checkerboard DNA-DNA hybridization until 180 days post therapy. The adjunctive use of antibiotics plus CHX significantly reduced the mean proportions of red complex species from subgingival biofilm and saliva (p < 0.05). Furthermore, the analysis of all intraoral niches showed a significantly lower mean proportion of the red complex species in the same group. In conclusion, the concomitant use of antimicrobial chemical control (systemic and local) demonstrated a beneficial effect on the composition of the oral microbiota.

Knowledge of bidirectional relationship between diabetes and periodontal disease among diabetes patients: A systematic review

INTRODUCTION

The bidirectional relationship between diabetes mellitus and periodontal disease has been reported in the literature, suggesting that poor glycemic control is strongly associated with increased risk of developing periodontal disease. Therefore, this systematic review evaluated the level of knowledge of this bidirectional relationship among patients with diabetes.

METHODS

This systematic review (protocol CRD42018117902) was conducted according to PRISMA guidelines. The following databases were considered: Medline/PubMed, Scopus, and Web of Science. Search strategy (April 05^th , 2021) considered proper combination of keywords and eligibility criteria. The quality of studies was evaluated using the Appraisal tool for Cross-Sectional Studies (AXIS).

RESULTS

Among the 328 records identified in the initial search, 24 studies were selected, considering a total of 8,693 patients. All studies used a cross-sectional design. Among the included studies, only five showed prevalence of knowledge higher than 50%, ranging from 5.8% to 75.9%. Interestingly, 58.0% of patients reported that they brush their teeth at least 1x/day, but only four studies reported that the dentist was the main source of information. In terms of methodology and result quality, just one study clearly showed all information evaluated by the AXIS tool. Most of studies did not report sample size calculations and did not used validated questionnaires to assess patient knowledge.

CONCLUSION

The results show that less than half of people with diabetes have knowledge about their increased risk for periodontal disease, and often the dentist is not the main source of information to motivate them.

The effect of antibiotics on the periodontal treatment of diabetic patients with periodontitis: A systematic review and meta-analysis

Background: The aim of this meta-analysis was to compare the effects of periodontal treatment with or without adjunctive antibiotic on periodontal status and blood glucose level in diabetic patients with periodontitis. Methods: A search using electronic database (MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials) and a manual search were performed up to July 2022. Eligible 13 RCTs were included according to inclusion and exclusion criteria. Reviewers independently performed data screening, data selection, data extraction, and risk of bias. Quality assessment was performed according to the Cochrane Handbook for Systematic Reviews of Interventions. Weighted mean differences and 95% confidence intervals (CIs) for continuous outcomes were calculated using random or fixed-effects models. This review is registered in the PROSPERO database (CRD42022347803). Results: Of the 13 included articles, eight were on the use of systemic antibiotics and five on topical antibiotics. The results showed statistically significant improvement in periodontal status (probing depth, clinical attachment loss and bleeding on probing) at 6 months with systematic antibiotics use (PD-6M p = 0.04, BOP-6M p < 0.0001, CAL-6M p = 0.002). The improvement in PD with topical antibiotics was statistically significant at 1 month (p = 0.0006). However, there was no statistically significant improvement in periodontal status at 3 months with adjuvant systemic antibiotics. Conclusion: Antibiotics can improve the periodontal condition of diabetic patients with periodontitis to a certain extent. In clinical practice, it is necessary to comprehensively consider the balance of benefits and risks before deciding whether to use antibiotics. Systematic Review Registration: Identifier CRD42022347803, https://www.crd.york.ac.uk/PROSPERO/.

Additional benefit of systemic antibiotics in subgingival instrumentation of stage III and IV periodontitis with Aggregatibacter actinomycetemcomitans: A retrospective analysis

AIM

To evaluate subgingival instrumentation (SI) in periodontitis stage III and IV, grade B and C with systemic antibiotics (AB) only after detection of Aggregatibacter actinomycetemcomitans.

MATERIALS AND METHODS

Patients of the Department of Periodontology of Goethe University Frankfurt/Germany were screened for microbiological testing between 2008 and 2018. All patients with aggressive and generalized severe chronic periodontitis were tested. In case of positive subgingival A. actinomycetemcomitans tests, SI was combined with AB; in all other cases it was not (nAB). Clinical examinations were performed before (T0), 12.4 (9.4/15.1) weeks after SI (T1), and at the last supportive periodontal care (T2; 3.1 [1.4/5.5] years after T1). Results at T1/T2 were assessed as "treat-to-target" endpoint (≤4 sites with probing pocket depths ≥5 mm).

RESULTS

Four-hundred and twenty-five patients (280 stage III/145 stage IV, 95 grade B/330 grade C) provided complete data (AB 144/nAB 281) for T0 and T1, and 332 (AB 121/nAB 211) for T2. At T1/T2, AB resulted in 53 (37%)/76 (63%) patients with "treat-to-target" endpoint, and nAB in 76 (27%)/91 (43%) (p = .038/.001).

CONCLUSIONS

In periodontitis stage III and IV, grade B and C with subgingival A. actinomycetemcomitans infection, SI with AB resulted in higher rate of "treat-to-target" endpoint than exclusive SI in patients without the infection.

Efficacy of Systemic Amoxicillin–Metronidazole in Periodontitis Patients with Diabetes Mellitus: A Systematic Review of Randomized Clinical Trials

Systemic amoxicillin–metronidazole was proven to be effective in managing periodontitis in systemically healthy patients. It was demonstrated that systemic antibiotic therapy can effectively improve clinical periodontal parameters and reduce periodontopathogenic organisms in the subgingival biofilm. However, the evidence for prescribing this drug combination to patients with diabetes remains insufficient. This systematic review was designed to evaluate the effectiveness of a systemic amoxicillin–metronidazole combination as an adjunct to nonsurgical periodontal therapy in patients with diabetes presenting with chronic periodontitis. The PubMed, Scopus, and Web of Science databases were electronically searched for randomized clinical trials in January 2022. Randomized clinical trials evaluating systemic amoxicillin–metronidazole therapy as an adjunct to nonsurgical periodontal therapy in patients with type 2 diabetes presenting with periodontitis were selected for screening. The qualities of the studies were assessed using the Cochrane Collaboration’s Tool for Assessing Risk of Bias Version 2.0 (ROB-2), and a GRADE assessment was applied to estimate the overall certainty of the evidence. Using predefined eligibility criteria, four clinical trials examining 209 patients were selected from the 611 articles identified in the search. Two studies reported a better reduction in clinical parameters when SRP was combined with systemic amoxicillin–metronidazole. Systemic amoxicillin–metronidazole was found to be as effective as clindamycin. Surgical therapy with systemic amoxicillin–metronidazole was more effective than nonsurgical therapy with systemic amoxicillin–metronidazole, even though both resulted in reduced clinical parameters. Combined amoxicillin–metronidazole was observed to reduce periodontal probing depth (PPD), clinical attachment level (CAL), and bleeding on probing (BOP) compared to no treatment or NSPT alone. However, the effect was not greater when compared to NSPT with clindamycin or surgical therapy with amoxicillin–metronidazole. Further randomized trials are required before clinical guidelines can be established for the use of systemic amoxicillin–metronidazole. Future randomized controlled clinical trials with long-term follow-ups are required to assess the efficacy of systemic antibiotic therapy in managing periodontitis in patients with diabetes.

Microbiological effects of amoxicillin plus metronidazole in the treatment of young patients with Stages III and IV periodontitis: A secondary analysis from a 1-year double-blinded placebo-controlled randomized clinical trial

BACKGROUND

Despite the body of evidence supporting the clinical benefits of metronidazole (MTZ) and amoxicillin (AMX) in the treatment of young patients with periodontitis, the microbiological outcomes of this antibiotic protocol have been less explored. This study evaluated the microbiological effects of adjunctive MTZ+AMX in the treatment of young patients with periodontitis.

METHODS

Subjects with periodontitis Stages III or IV and ≤30 years old were randomly allocated to receive scaling and root planing (SRP) with placebo (n = 15) or with MTZ (400 mg) and AMX (500 mg) three times a day for 14 days (n = 15). Nine subgingival biofilm samples per subject (three samples from each probing depth (PD) category: ≤3, 4-6, and ≥7 mm) were collected at baseline and 3-, 6-, and 12-months post-treatment and individually analyzed for 40 bacterial species by checkerboard DNA-DNA hybridization.

RESULTS

Thirty subjects (15/group) with mean ages 27.6 ± 3.5 (control) and 26.8 ± 3.9 (test) were included. At 12 months post-therapy, the antibiotic group harbored lower proportions of red complex (1.3%) than the placebo group (12.5%) (p < 0.05). SRP + MTZ+AMX was more effective than mechanical treatment in reducing levels/proportions of several pathogens and increasing proportions of Actinomyces species (p < 0.05). Levels/proportions of Aggregatibacter actinomycetemcomitans were only reduced in the antibiotic group (p < 0.05). This group also exhibited greater reduction in the number of sites with PD ≥5 mm and higher percentage of subjects reaching the clinical end point for treatment (≤4 sites with PD ≥5 mm) than the control group (p < 0.05).

CONCLUSION

SRP+MTZ+AMX allowed for establishing a long-term healthier subgingival biofilm community and periodontal clinical condition, than SRP only.

Randomized clinical trials in periodontology: focus on outcomes selection

Randomized clinical trials (RCTs) are human studies carried out to compare different treatments or interventions, and their results are used to support clinical decision-making and improve patient care. Herein, the aim of this study was to review the selection process of study outcomes in periodontology. Primary outcomes should draw the main conclusions of the study, whereas secondary outcomes should only be used to help explain the main findings and generate future research hypothesis. Outcomes are classified as clinically relevant (CROs) or surrogate outcomes. CROs - the first option for primary outcome variables - should convey not only substantial health benefits, but also be deemed important by patients. In periodontology, tooth loss/retention and oral health-related quality of life (OHRQoL) are examples of CROs. While tooth loss has main limitations as a primary outcome, emerging evidence suggest that patient-reported outcome measures (PROMs) can accurately detect OHRQoL following periodontal therapy. When CROs cannot be assessed, validated surrogate outcomes can be used as proxies. Primary outcome variables should reflect a treatment endpoint at the patient level that can be easily used to inform decision-making in daily practice. These outcomes should allow the implementation of a treat-to-target concept in which the intervention can be clearly judged against a prespecified treatment target. Recently, the presence of at most 4 sites with periodontal probing depth ≥5 mm post-treatment was suggested as an effective endpoint for periodontal trials. In perspective, a combination of validated clinical parameters and PROMs will provide a more comprehensive assessment of periodontal treatments.

Sulfonylureas for Treatment of Periodontitis-Diabetes Comorbidity-Related Complications: Killing Two Birds With One Stone

Periodontitis is one of the most prevalent oral inflammatory diseases leading to teeth loss and oral health problems in adults. Periodontitis mainly affects periodontal tissue by affecting the host immune system and bone homeostasis. Moreover, periodontitis is associated with various systemic diseases. Diabetes is a metabolic disease with systemic effects. Both periodontitis and diabetes are common inflammatory diseases, and comorbidity of two diseases is linked to exacerbation of the pathophysiology of both diseases. Since bacterial dysbiosis is mainly responsible for periodontitis, antibiotics are widely used drugs to treat periodontitis in clinics. However, the outcomes of antibiotic treatments in periodontitis are not satisfactory. Therefore, the application of anti-inflammatory drugs in combination with antibiotics could be a treatment option for periodontitis-diabetes comorbidity. Anti-diabetic drugs usually have anti-inflammatory properties and have shown beneficial effects on periodontitis. Sulfonylureas, insulin secretagogues, are the earliest and most widely used oral hypoglycemic drugs used for type-2 diabetes. Studies have found that sulfonylurea drugs can play a certain role in the mitigation of periodontitis and inflammation. This article reviews the effects of sulfonylurea drugs on the mitigation of periodontitis-diabetes comorbidity-related inflammation, bone loss, and vascular growth as well as the involved molecular mechanisms. We discuss the possibility of a new application of sulfonylureas (old drug) to treat periodontitis-diabetes comorbidity.

Clindamycin as an Alternative Option in Optimizing Periodontal Therapy

Periodontal disease is an oral infectious and inflammatory disease caused by microorganisms that determine the host-mediated destruction of soft and hard periodontal tissues, which ultimately leads to tooth loss. Periodontitis affects a large part of the population, with various degrees of severity. Treatment consists of etiologic therapy: the removal of biofilm through mechanical debridement plus microbial elimination by supplementary measures. Antibiotic administration, either systemically or through local delivery, has been shown to improve clinical outcomes after mechanical periodontal treatment. Clindamycin is a lincosamide with a broad spectrum, being active against aerobic, anaerobic, and β-lactamase-producing bacteria. This antibiotic offers several advantages and some disadvantages and has been used in periodontal treatment both systemically and locally with various degrees of success. Among the properties that recommend it for periodontal treatment is the bacteriostatic effect, the inhibition of bacterial proteins synthesis, the enhancement of neutrophil chemotaxis, phagocytosis and the oxidative burst–oxidative stress storm. Furthermore, it is easily absorbed at the level of oral tissues in a considerable amount. This substantial tissue penetration, especially inside the bone, is synergistic with a stimulating effect on the host immune system. The aim of this review is to explore the applicability of this antibiotic agent and to evaluate its antimicrobial potential and limitations at the level of the oral biofilm associated with periodontal disease.

Clinical, microbiological, and immunological effects of systemic probiotics in periodontal treatment: study protocol for a randomized controlled trial

BACKGROUND

The association of scaling and root planing (SRP) with systemic metronidazole (MTZ) plus amoxicillin (AMX) has shown to be an effective treatment protocol, particularly for periodontitis stages III and IV, generalized. More recently, probiotics have also been suggested as a promising adjunctive treatment for periodontal diseases due to their antimicrobial and anti-inflammatory properties. Therefore, the aim of this randomized clinical trial (RCT) is to evaluate the clinical, microbiological, and immunological effects of probiotics as adjuncts to SRP alone or with MTZ+AMX in the treatment of periodontitis.

METHODS

Subjects with periodontitis are being randomly assigned to receive (i) SRP alone, or with (ii) two probiotic lozenges/day for 90 days (Prob), (iii) MTZ (400 mg) and AMX (500 mg) thrice a day (TID) for 14 days (MTZ+AMX), or (iv) Prob and MTZ+AMX. Subjects are being monitored for up to 12 months post-treatment. Nine subgingival plaque samples per patient are being collected at baseline and at 3, 6, and 12 months post-therapy and analyzed by checkerboard DNA-DNA hybridization for 40 bacterial species. Peripheral blood and gingival crevicular fluid (GCF) of four randomly selected periodontal sites will be analyzed by means of a multiplex fluorescent bead-based immunoassay for 17 cyto/chemokines.

STATISTICAL ANALYSES

The significance of differences in each group (over the course of the study) will be sought using repeated measures ANOVA or Friedman tests and among groups (at each time point) using either ANOVA/ANCOVA or Kruskal-Wallis tests, depending on normality of the data. The chi-square test will be used to compare differences in the frequency of subjects achieving the clinical endpoint for treatment (≤ 4 sites with PD ≥ 5 mm) at 1 year and of self-perceived adverse effects. A stepwise forward logistic regression analysis will be performed in order to investigate the impact of different predictor variables on the percentage of patients achieving the clinical endpoint for treatment. The Number Needed to Treat (NNT) with different treatment protocols will be also calculated. Statistical significance will be set at 5%.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03733379. Registered on November 7, 2018.

Did Omics change periodontal therapy?

The starting point for defining effective treatment protocols is a clear understanding of the etiology and pathogenesis of a condition. In periodontal diseases, this understanding has been hindered by a number of factors, such as the difficulty in differentiating primary pathogens from nonpathogens in complex biofilm structures. The introduction of DNA sequencing technologies, including taxonomic and functional analyses, has allowed the oral microbiome to be investigated in much greater breadth and depth. This article aims to compile the results of studies, using next-generation sequencing techniques to evaluate the periodontal microbiome, in an attempt to determine how far the knowledge provided by these studies has brought us in terms of influencing the way we treat periodontitis. The taxonomic data provided, to date, by published association and elimination studies using next-generation sequencing confirm previous knowledge on the role of classic periodontal pathogens in the pathobiology of disease and include new species/genera. Conversely, species and genera already considered as host-compatible and others less explored were associated with periodontal health as their levels were elevated in healthy individuals and increased after therapy. Functional and transcriptomic analyses also demonstrated that periodontal biofilms are taxonomically diverse, functionally congruent, and highly cooperative. Very few interventional studies to date have examined the effects of treatment on the periodontal microbiome, and such studies are heterogeneous in terms of design, sample size, sampling method, treatment provided, and duration of follow-up. Hence, it is still difficult to draw meaningful conclusions from them. Thus, although OMICS knowledge has not yet changed the way we treat patients in daily practice, the information provided by these studies opens new avenues for future research in this field. As new pathogens and beneficial species become identified, future randomized clinical trials could monitor these species/genera more comprehensively. In addition, the metatranscriptomic data, although still embryonic, suggest that the interplay between the host and the oral microbiome may be our best opportunity to implement personalized periodontal treatments. Therapeutic schemes targeting particular bacterial protein products in subjects with specific genetic profiles, for example, may be the futuristic view of enhanced periodontal therapy.

Microbiome changes in young periodontitis patients treated with adjunctive metronidazole and amoxicillin

BACKGROUND

To our knowledge, to date, no studies have comprehensively assessed the changes occurring in the subgingival microbiome of young patients with periodontitis treated by means of mechanical and antibiotic therapy. Thus, this study aimed to use next-generation sequencing to evaluate the subgingival microbial composition of young patients with severe periodontitis treated with scaling and root planing and systemic metronidazole and amoxicillin.

METHODS

Subgingival samples from healthy individuals and shallow and deep sites from periodontitis patients were individually collected at baseline and 90 days post-treatment. The samples were analyzed using 16S rRNA-gene sequencing (MiSeq-Illumina) and QIIME pipeline. Differences between groups for the microbiological data were determined using principal coordinate analysis (PCoA), linear mixed models, and the PERMANOVA test.

RESULTS

One hundred samples were collected from 10 periodontitis patients and seven healthy individuals. PCoA analysis revealed significant partitioning between pre-and post-treatment samples. No major differences in the composition of the subgingival microbiota were observed between shallow and deep sites, at baseline or at 90-days post-treatment, and the microbiome of both site categories after treatment moved closer in similarity to that observed in periodontal health. Treatment significantly improved all clinical parameters and reduced the relative abundance of classical periodontal pathogens and of Fretibacterium fastidiosum, Eubacterium saphenum, Porphyromonas endodontalis, Treponema medium, Synergistetes, TM7, and Treponema spp, and increased that of Actinomyces, Rothia, Haemophilus, Corynebacterium, and Streptococci spp.

CONCLUSION

Mechanical treatment associated with metronidazole and amoxicillin promoted a beneficial change in the microbiome of young individuals with severe periodontitis.

Metronidazole and amoxicillin for patients with periodontitis and diabetes mellitus: 5-year secondary analysis of a randomized controlled trial

BACKGROUND

The aim of this study was to perform a 5-year follow-up analysis of a previously-published randomized trial (RCT) evaluating the 2-years effects of metronidazole (MTZ) plus amoxicillin (AMX) as adjuncts to scaling and root planing (SRP) in the treatment of periodontitis in type 2 diabetic patients.

METHODS

Volunteers who received periodontal treatment in the aforementioned RCT were selected for clinical and microbiological evaluation. Patients did not receive regular supportive periodontal therapy (SPT) from 2 to 5 years post-treatment.

RESULTS

Of the patients enrolled in the RCT, 43% entered this study (n = 10/control and 15/test group). Most of clinical parameter values, including the number of sites with probing depth ≥ 5 mm (primary outcome variable), were reduced at 5 years post-therapy when compared with baseline in the antibiotic-treated group (P < 0.05), but presented higher values than those at 2 years (P < 0.05). The mean proportions of microbial complexes did not differ between MTZ+AMX+SRP and SRP-only groups at 5 years post-treatment (P > 0.05).

CONCLUSION

Diabetic patients treated with adjunctive MTZ+AMX were better maintained over a period of 5 years than those treated with SRP only. However, the clinical and microbiological benefits obtained up to 2 years post-treatment were not fully sustained in these patients who did not receive SPT between 2 and 5 years post-treatment.

A systematic review on bacterial community changes after periodontal therapy with and without systemic antibiotics: An analysis with a wider lens

BACKGROUND

This systematic review aimed to provide a comprehensive view on microbial community shifts after periodontal therapy with and without systemic antibiotics, conducted in randomized controlled trials (RCTs).

METHODS

Search functions in PubMed, Scopus, the Web of Knowledge, and the Cochrane Oral Health Library databases were used to locate studies published up to December 2018 that reported at least two bacteria before and after periodontal therapy. Gray literature and manual searching were done. Information about reported bacteria in those studies were extracted, and a descriptive microbial community analysis was conducted to observe trends and influencing factors on microbial dynamics. Methodological aspects were examined, including the bacterial detection method, heterogeneity of procedures, and risk of bias (RoB) of the studies.

RESULTS

The 30 included studies reported 130 different bacterial genera. Four different detection methods were reported: cultivation, polymerase chain reaction, DNA-DNA-checkerboard hybridization, and 16S rDNA amplicon sequencing. No general compositional change between the antibiotic and placebo groups could be found after therapy on the community level. Fifty-five bacteria were reported in two or more studies. Of those, 24 genera decreased and 13 increased more frequently after antibiotic use. Great heterogeneity between procedures and variability in RoB were found among the studies.

CONCLUSIONS

Microbial shifts occurred regardless of the use of antibiotics. Antibiotic therapy seems to induce more changes in single bacteria. The heterogeneity in methods and reporting of the included studies preclude clinical recommendations on the use or not of adjunctive antibiotics. The present results may guide further research on the topic.

Effect of periodontal treatment in patients with periodontitis and diabetes: systematic review and meta-analysis

The evidence is inconclusive regarding the effect of periodontal treatment on glycemic control and systemic inflammation in patients with type 2 diabetes (T2D) and periodontitis

Efficacy of clindamycin compared with amoxicillin-metronidazole after a 7-day regimen in the treatment of periodontitis in patients with diabetes: a randomized clinical trial

OBJECTIVE

To determine the efficacy of clindamycin compared with amoxicillin-metronidazole after a 7-day regimen during nonsurgical treatment of periodontitis in patients with type 2 diabetes mellitus.

RESEARCH DESIGN AND METHODS

In this double-blind, randomized clinical trial, a total of 42 patients with chronic periodontitis and type 2 diabetes were included. Patients were randomly assigned to treatment with either clindamycin or amoxicillin-metronidazole three times a day during 7 days. Clinical determinations (probing depth, bleeding on probe, and plaque index) were performed to determine the extent and severity of periodontitis before and after the pharmacological treatment.

RESULTS

After 7 days of administration of clindamycin or amoxicillin-metronidazole, no differences were observed between the clinical determinations, probing depth (0.44 vs 0.50 mm, p=0.624), plaque index (17.62 vs 15.88%, p=0.910), and bleeding on probing (16.12 vs 22.17%, p=0.163), respectively. There were no adverse events in either group.

CONCLUSION

The administration during 7 days of clindamycin or amoxicillin/metronidazole showed the same efficacy for the reduction of probing depth, plaque index, and bleeding on probing in patients with periodontitis and type 2 diabetes.

Effect of compliance during periodontal maintenance therapy on levels of bacteria associated with periodontitis: A 6-year prospective study

BACKGROUND

It is well established that regular compliance during periodontal maintenance therapy (PMT) maintains the stability of periodontal clinical parameters obtained after active periodontal therapy (APT). However, compliance during PMT has not yet been related to subgingival bacterial levels. Thus, this study followed individuals in PMT over 6 years and longitudinally evaluated the effects of compliance on periodontitis-associated bacterial levels and its relation to periodontal status.

METHODS

From a 6-year prospective cohort study with 212 individuals in PMT, 91 were determined to be eligible. From this total, 28 regular compliers (RC) were randomly selected and matched for age and sex with 28 irregular compliers (IC). Complete periodontal examination and microbiological samples were obtained 5 times: T1 (prior to APT), T2 (after APT), T3 (2 years), T4 (4 years), and T5 (6 years). Total bacteria counts and levels of Actinomyces naeslundii, Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola were evaluated through quantitative polymerase chain reaction.

RESULTS

RC had less tooth loss and better clinical and microbiological conditions over time when compared with IC. IC had higher total bacterial counts and higher levels of T. denticola. Moreover, among IC, total bacterial counts were positively associated with plaque index and bleeding on probing, while levels of A. naeslundii, T. forsythia, and T. denticola were negatively associated with clinical attachment loss (4 to 5 mm) among RC.

CONCLUSIONS

Compliance positively influenced subgingival microbiota and contributed to stability of periodontal clinical status. Regular visits during PMT sustained microbiological benefits provided by APT over a 6-year period.

Novel 20% doxycycline-loaded PLGA nanospheres as adjunctive therapy in chronic periodontitis in type-2 diabetics: randomized clinical, immune and microbiological trial

OBJECTIVE

This study evaluated the clinical, microbiological, and immunological results of poly lactic-co-glycolic acid (PLGA) nanospheres containing 20% doxycycline (DOXY) in the treatment of type-2 diabetic patients (DM-2) with chronic periodontitis (CP).

MATERIAL AND METHODS

A parallel, double-blind, randomized, placebo-controlled clinical trial was conducted in DM-2 presenting severe and generalized CP. All patients received one-stage full-mouth ultrasonic debridement (FMUD) and they were randomly divided into two groups: PLAC (n = 20)-local application of placebo PLGA nanospheres, and DOXY (n = 20)-local application of doxycycline-loaded nanospheres; both in six non-contiguous sites. Clinical, metabolic (fasting plasma glucose level-FPG and glycated hemoglobin-HbA1c), cytokine pattern (multiplexed bead immunoassay) and microbiological assessments were performed at baseline, and 1, 3, and 6 months after treatment.

RESULTS

Both groups showed clinical improvement in all parameters after treatment (p < 0.05). Deep pockets showed improvements in bleeding on probing-BoP (3 and 6 months), PD (at 3 months), and CAL gain (at 1 and 3 months) favoring DOXY (p < 0.05). The percentage of sites presenting PD reduction and CAL gain ≥ 2 mm was higher in DOXY at 3 months (p < 0.05). DOXY group exhibited a significant increase in the levels of anti-inflammatory interleukin (IL)-10 and a reduction in IL-8, IFN-y, IL-6, and IL-17 (p < 0.05), significant reduction in periodontal pathogens (p < 0.05), and a lower mean percentage of HbA1C at 3 months (p < 0.05).

CONCLUSION

DOXY nanospheres may be considered a potential adjunct to mechanical debridement in the therapy of periodontitis in DM-2, offering additional benefits in deep pockets, improving the cytokine profile, and reducing periodontal pathogen levels.

CLINICAL RELEVANCE

The use of locally applied doxycycline nanospheres may represent an adjunctive therapeutic approach in the treatment of periodontal disease in type-2 diabetic patients, achieving additional benefits in the local modulation of cytokines, microbial reduction, and clinical parameters, especially in deep pockets.

Clinical and microbiological effects of scaling and root planing, metronidazole and amoxicillin in the treatment of diabetic and non-diabetic subjects with periodontitis: A cohort study

AIM

To evaluate if non-diabetic subjects with periodontitis respond better than subjects with type 2 diabetes to the treatment protocol of scaling and root planing (SRP), metronidazole (MTZ) and amoxicillin (AMX).

MATERIAL AND METHODS

Diabetic and nondiabetic subjects with severe periodontitis received SRP + MTZ (400 mg/thrice a day [TID]) + AMX (500 mg/TID) for 14 days. Subgingival biofilm samples were analyzed by checkerboard DNA-DNA hybridization for 40 bacterial species. Subjects were monitored at baseline, 3, 6 and 12 months post-therapy.

RESULTS

Twenty-nine type 2 diabetics and 29 non-diabetic subjects participated of this study. Of the non-diabetics and diabetics, 68.9% and 75.9%, respectively, reached the clinical endpoint for treatment (≤4 sites with probing depth [PD] ≥5 mm) at 1 year post-therapy (p > 0.05). The diabetic group presented lower mean clinical attachment gain from baseline to 1 year post-therapy and higher mean proportions of the red and orange complexes than the non-diabetic group (p < 0.05).

CONCLUSIONS

Non-diabetic subjects with severe periodontitis did not respond better than type 2 diabetic subjects to the treatment protocol of SRP + MTZ + AMX, both in terms of achieving the clinical endpoint for treatment and of PD improvement. Diabetic subjects exhibited a slightly worse microbiological response and showed a healing process more associated with gingival recession than the non-diabetics.

Efficacy of systemic antibiotics in nonsurgical periodontal therapy for diabetic subjects: a systematic review and meta-analysis

OBJECTIVES

To evaluate the effects of systemic antibiotics as adjuncts to nonsurgical periodontal treatment (NSPT), as opposed to using NSPT alone, on periodontal clinical parameters of diabetic patients with periodontitis.

MATERIALS AND METHODS

Randomised controlled trials with a follow-up of 3 months or more, assessing the effects of NSPT in combination with antibiotics, in diabetic patients with periodontitis were included. Trials published up to August 2016 were identified from MEDLINE, EMBASE and LILACS databases. Meta-analyses were conducted to determine changes in clinical attachment level (CAL), probing pocket depth (PPD), bleeding on probing (BOP) and gingival index (GI). Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed in this review.

RESULTS

Of the 164 papers potentially admissible to this systematic review, 15 articles on 11 randomised clinical trials were considered as eligible. The results of the meta-analyses presented a modest additional benefit of 0.14 mm (95% confidence interval: 0.08-0.20) in reducing PPD but no further benefit in CAL gain.

CONCLUSION

When the data for all antibiotic protocols were considered together for the treatment of periodontitis patients with DM, a significant, albeit small, reduction of PPD and no improvement in CAL gain was observed. When the antibiotic protocols were analysed separately, the combination of amoxicillin plus metronidazole yielded the best results for PPD.

The ideal time of systemic metronidazole and amoxicillin administration in the treatment of severe periodontitis: study protocol for a randomized controlled trial

Background

The combination of systemic metronidazole (MTZ) and amoxicillin (AMX) with scaling and root planing (SRP) has shown to be an effective periodontal treatment. However, some essential issues associated with the use of these antibiotics remain unanswered, such as the ideal time of administration during the course of periodontal treatment. Although these agents are often prescribed after the healing phase of the SRP procedure, there is biological plausibility to support its use in conjunction with the mechanical treatment. However, to date, no placebo controlled randomized clinical trial (RCT) has directly compared these two protocols. Therefore, the aim of this RCT is to compare the clinical, microbiological and immunological effects of the adjunctive systemic MTZ + AMX administered in different phases of the treatment of severe periodontitis.

Methods

Subjects with severe periodontitis (n = 180) are being randomly assigned into three groups (n = 60/group): (i) SRP-only (control group), SRP in combination with 400 mg MTZ + 500 mg AMX, starting (ii) at the first SRP session (active phase group), or (iii) after 3 months of its completion (healing phase group). All volunteers are receiving clinical and microbiological evaluation at baseline, 3, 6 and 12 months, and immunological assessment at baseline and 12 months post-therapy. Nine subgingival biofilm samples are being collected per subject and analyzed for counts and proportions of 40 bacterial species by checkerboard DNA-DNA hybridization, and six gingival crevicular fluid samples are being collected and analyzed for the levels of 20 chemokines by multiplex immunoassay. The primary outcome variable is the number of volunteers reaching the clinical endpoint for treatment (≤ 4 sites with probing depth ≥5 mm) at 1 year post-therapy. Differences in clinical, microbiological and immunological parameters among groups and over time will be evaluated using analysis of variance, analysis of covariance and the Chi-square and Tukey tests. Microbiological and immunological analyses will be performed using adjustments for multiple comparisons. Statistical significance will be set at 5%.

Trial registration

ClinicalTrials.gov, NCT02954393. Registered on 3 November 2016.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2540-8) contains supplementary material, which is available to authorized users.