Effects of Non-Surgical Mechanical Therapy on the Subgingival Microbiota of Brazilians With Untreated Chronic Periodontitis: 9-Month Results

A literature review of bioactive substances for the treatment of periodontitis: In vitro, in vivo and clinical studies

Periodontitis is a common chronic inflammatory disease of the supporting tissues of the tooth that involves a complex interaction of microorganisms and various cell lines around the infected site. To prevent and treat this disease, several options are available, such as scaling, root planning, antibiotic treatment, and dental surgeries, depending on the stage of the disease. However, these treatments can have various side effects, including additional inflammatory responses, chronic wounds, and the need for secondary surgery. Consequently, numerous studies have focused on developing new therapeutic agents for more effective periodontitis treatment. This review explores the latest trends in bioactive substances with therapeutic effects for periodontitis using various search engines. Therefore, this study aimed to suggest effective directions for therapeutic approaches. Additionally, we provide a summary of the current applications and underlying mechanisms of bioactive substances, which can serve as a reference for the development of periodontitis treatments.

Brief literature review and comprehensive bioinformatics analytics unravel the potential mechanism of curcumin in the treatment of periodontitis

OBJECTIVE

Periodontitis is a chronic oral disease prevalent worldwide, and natural products are recommended as adjunctive therapy due to their minor side effects. Curcumin, a widely used ancient compound, has been reported to possess therapeutic effects in periodontitis. However, the exact mechanism underlying its activity remains unclear. In this context, the present study aimed to conduct computational simulations to uncover the potential mechanism of action of Curcumin in the treatment of periodontitis.

MATERIALS AND METHODS

Single-cell analysis was conducted using a dataset (i.e., GSE164241) curated from the Gene Expression Omnibus (GEO) database through an R package "Seurat package." Bulk RNA sequencing data were curated from GSE10334 and GSE16134 and processed by R package "Limma." Then, the marker genes in the single-cell transcriptome and differentially expressed genes (DEGs) in the bulk transcriptome were integrated. Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses were also carried out to reveal their functionalities. Key targets were mined from their protein-protein interaction (PPI) network topologically. Afterward, molecular docking was performed. The top-ranked pose was subjected to molecular dynamics simulations to investigate the stability of the docking result.

RESULTS

FOS, CXCL1, CXCL8, and IL1B, were filtered after a series of selected processes. The results of molecular modeling suggested that except for IL1B, the Vena Scores of the rest exceeded -5 kcal/mol. Furthermore, the molecular dynamic simulation indicated that the binding of the CXCL8-Curcumin complex was stable over the entire 100 ns simulation.

CONCLUSION

The present study unlocked the binding modes of CXCL1, FOS, and CXCL8 with the Curcumin molecule, which were relatively stable, especially for CXCL8, hindering its promising potential to serve as the critical targets of Curcumin in periodontitis treatment.

Antibacterial efficacy of a pH-neutral electrolyzed super-oxidized solution for nonsurgical periodontal treatment

Objective

Mouthwash is effective in maintaining oral hygiene in patients; however, there is concern that it may adversely affect human oral mucosa. We evaluated a pH-neutral electrolyzed super-oxidized solution (ESS, tradename OxOral®) combined with dental scaling in periodontitis patients. This longitudinal study was conducted with 34 patients divided into three groups. The control group treated with scaling plus saline, the second with scaling plus ESS mouthwash, and another with scaling plus ESS mouthwash and gel. The plaque index (PI), gingival index (GI), and probing depth (PD) were determined before and after periodontal treatment.

Results

The final PI and GI decreased compared with the initial measurements in the three treatment groups (p < 0.05). Scaling plus ESS mouthwash and gel significantly reduced the final PI, GI, and DP compared to the control group (p < 0.05).

Conclusion

Our study shows the antiseptic properties of ESS with mouthwash and gel. Further studies are needed to verify the results.

Effects of Curcuma as an adjunct therapy on periodontal disease: A systematic review and meta-analysis

BACKGROUND

Periodontal disease (PD) is the second most prevalent buccal infectious condition in adults. Owing to its multifactorial etiology, treatment and maintenance are challenging. Scaling and root planing, associated with adequate plaque control, are considered the gold standard treatments for this disease. However, the instrumentation techniques can fail to completely eliminate calculus, particularly in higher grade and progression rated PD cases, and the continuing efficient removal of the biofilm by the patient can limit the long-term response of this treatment. Anti-infective herbal products, such as Curcuma, have been added as adjuvant therapy to prolong periodontal treatment outcomes.

OBJECTIVE

This systematic review aimed to summarize and evaluate whether Curcuma can contribute to PD treatment when applied as an adjunct to the standard scaling and root planing therapy.

DATA SOURCES

We searched databases using specific keywords and Boolean operators and systematically conducted the extraction and analysis according to the PROSPERO (CRD42019145691) database. The main eligibility criteria were randomized clinical trials in humans published in the English language.

RESULTS

Twelve studies were included in the review and 11 in the meta-analysis. Quantitative analysis of different clinical parameters was described. In comparison with the control group, Curcuma was associated with a reduction in pocket depth after 90 days of treatment (mean deviation: 0.48; 95% confidence interval: 0.89-0.08).

CONCLUSION

This systematic review and meta-analysis indicated that Curcuma is an effective product when applied as adjunct therapy for PD treatment. This improved the clinical and microbiological parameters.

Effects of curcumin gel on osteoclastogenic bone markers in experimental periodontitis and alveolar bone loss in wistar rats

BACKGROUND/PURPOSE

Curcumin has anti-inflammatory impacts and was suggested as an inflammatory disease therapy. This study aimed to investigate the implications of curcumin gel on experimental periodontitis (EPD) and alveolar bone loss in rats.

MATERIALS AND METHODS

In this study, twenty-four male Wistar rats were divided equally into four groups: negative control (with no EPD); positive control (EPD induced around lower centrals without treatment); control-treated group: EPD treated with chlorhexidine; and test EPD group treated with curcumin. After 30 days, the serum concentrations of RANKL and IL-1β were measured via ELISA. All animals were sacrificed, and mandibular central incisors with the periodontium were removed. The lingual probing depth and radiographical alveolar bone loss were measured, then samples processed for routine preparation of H&E stained sections and histologically assessed for counting inflammatory cells, osteoclasts, and PDL width.

RESULTS

A significant decrease in the inflammatory cells infiltration, probing depth, and osteoclast numbers with the improvement of PDL associated with a reduction in RANKL and IL-1β serum concentration were seen in both EPD treated groups.

CONCLUSION

Curcumin is as effective as chlorhexidine in treating experimental periodontitis in rats. It was demonstrated to stop bone destruction related to periodontitis by regulating the RANKL and IL-1β markers level in the blood.

Does Chemically Modified Curcumin Control the Progression of Periodontitis? A Systematic Review

BACKGROUND

Recently, pharmacologic approaches have been seen in utilizing matrix metalloproteinase inhibitors (MMP-I) to prohibit the destruction of connective tissue accompanied by erythrogenic inflammatory diseases such as periodontitis. However, curcumin characteristics have been described to be effective in reducing inflammatory mediators and matrix metalloproteinase (MMP). But, due to its poor solubility and bioavailability, a chemically modified curcumin (CMC 2.24) has been used.

OBJECTIVE

The purpose of this research is to review and analyze the animal attempts which investigate the impact of CMC2.24 on periodontitis.

MATERIALS AND METHODS

Our study was based on reviewing the English preclinical studies using CMC2.24 on an induced periodontal disease which were published up to 2020, only randomized control trials (RCTs) were included. Databases were used from electronic websites including PubMed, ScienceDirect, and Google scholar.

RESULTS

Seven experimental trials involving 162 rats and 8 dogs were included in the present systematic review. Six studies investigated LPS-induced experimental periodontitis, two of them worked on diabetes-associated periodontitis, while one study worked on naturally occurring periodontitis. All included studies revealed that CMC 2.24 reduced alveolar bone loss as well as inhibited the MMP.

CONCLUSION

Collectively, we concluded that CMC 2.24 has significant implications in prohibiting the progression of bone loss.

Subgingival microbiota in overweight and obese young adults with no destructive periodontal disease

BACKGROUND

This study analyzed the levels of a specific group of periodontal health/disease-related oral bacteria in the subgingival biofilm of young adults with overweight (OW) and obesity (OB), and no destructive periodontal disease.

METHODS

Full-mouth periodontal assessment and subgingival biofilm sampling were performed in individuals with normal weight (NW) (BMI [body mass index] ≥18.5 to ≤24.9 kg/m² ; n = 29), OW (BMI ≥25 to ≤29.9 kg/m² ; n = 26), or OB (BMI ≥30 kg/m² ; n = 22). BMI, waist (WC) and hip (HC) circumferences, and waist-hip ratio (WHR) were established for every individual. Biofilm samples were analyzed by checkerboard. Spearman coefficient, linear, and logistic regression analyses were obtained.

RESULTS

Gingivitis was detected in 45% NW, 65% OW, and 73% OB individuals. NW patients presented significantly less calculus and supragingival biofilm than OB. OW, and OB individuals had significantly higher levels of Porphyromonas gingivalis and Tannerella forsythia than NW patients (P <0.05). Treponema denticola correlated with BMI (rho = 0.31), WC (rho = 0.28), and HC (rho = 0.29), P≤0.01. Linear regression analysis showed significant (P <0.05) positive associations between BMI, WC, HC, and WHR indicators and Prevotella spp., Lactobacillus spp., V. parvula, and A. actinomycetemcomitans (Aa); negative associations were found between Capnocytophaga spp., WC, and HC (β = -0.29 and β = -0.37, respectively; P <0.01). However, the interaction of Prevotella spp. and T. forsythia decreased the likelihood of an individual to be diagnosed as OW/OB (OR 0.183 [95% CI, 0.062-0.540]).

CONCLUSIONS

Few periodontal pathogens differed in levels between NW and OW/OB individuals without destructive periodontal disease. Moreover, Aa, T. denticola, and Prevotella spp. were associated with clinical parameters of obesity.

Understanding the microbial components of periodontal diseases and periodontal treatment-induced microbiological shifts

In the mid-1960s the microbial aetiology of periodontal diseases was introduced based on classical experimental gingivitis studies . Since then, numerous studies have addressed the fundamental role that oral microbiota plays in the initiation and progression of periodontal diseases. Recent advances in laboratory identification techniques have contributed to a better understanding of the complexity of the oral microbiome in both health and disease. Modern culture-independent methods such as human oral microbial identification microarray and next-generation sequencing have been used to identify a wide variety of microbial taxa residing in the gingival sulcus and the periodontal pocket. The first theory of the 'non-specific plaque' hypothesis gave rise to the 'ecological plaque' hypothesis and more recently to the 'polymicrobial synergy and dysbiosis hypothesis'. Periodontitis is now considered to be a multimicrobial inflammatory disease in which the various bacterial species within the dental biofilm are in a dysbiotic state and this imbalance favours the establishment of chronic inflammatory conditions and ultimately the destruction of tooth-supporting tissues. Apart from the known putative periodontal pathogens, the whole biofilm community is now considered to play a role in the establishment of inflammation and the initiation and progression of periodontitis in a susceptible host. Treatment is unlikely to eliminate putative pathogens but, when it is thoroughly performed it has the potential to establish a healthy ecosystem by altering the microbial community in numbers and composition and also contribute to the maturation of the host immune response.

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.

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.

Ozone application as adjunctive therapy in chronic periodontitis: Clinical, microbiological and biochemical aspects

Background/purpose

The application of ozone as an adjunctive treatment represents a new approach in the management of chronic periodontitis. The purpose of this study was to evaluate the clinical, biochemical and microbiological efficacy of ozone treatment as an adjunct to scaling and root planing (SRP) in generalized chronic periodontitis (GCP) patients.

Materials and methods

Eighteen patients (9 males and 9 females; aged from 28 to 47 years, mean age of 40 ± 6.51 years) with GCP were recruited in the study. In a split mouth design, two quadrants in each patient were randomly allocated to SRP-alone or SRP-ozone therapy (SRP + OT) groups by coin toss method. Subgingival plaque and gingival crevicular fluid (GCF) samples were collected at baseline, following 1st and 3rd months. The clinical parameters were monitored at baseline and after 3 months. Microbiological parameters were analyzed by quantitative-PCR and GCF biomarkers were determined by ELISA. Results were analyzed statistically.

Results

Statistically significant improvements in all clinical parameters were accompanied by a reduction in microbiological and biochemical parameters in both treatment groups. SRP treatment resulted in a significant reduction of Porphyromonas gingivalis (Pg) at 1st month and Tannerella forsythia (Tf) and Prevotella intermedia (Pi) at 3 months. Following SRP treatment the interleukin (IL)-8 levels were significantly reduced at month 1. There were no significant differences between two treatments for any of the parameters.

Conclusion

Within the limitations of this study, adjunctive ozone therapy did not provide additional benefits to clinical, microbiological and biochemical parameters over SRP in chronic periodontitis patients.

Microbiological outcomes from different periodontal maintenance interventions: a systematic review

This study aimed to investigate the differences in the subgingival microbiological outcomes between periodontal patients submitted to a supragingival control (SPG) regimen as compared to subgingival scaling and root planing performed combined with supragingival debridement (SPG + SBG) intervention during the periodontal maintenance period (PMP). A systematic literature search using electronic databases (MEDLINE and EMBASE) was conducted looking for articles published up to August 2016 and independent of language. Two independent reviewers performed the study selection, quality assessment and data collection. Only human randomized or non-randomized clinical trials with at least 6-months-follow-up after periodontal treatment and presenting subgingival microbiological outcomes related to SPG and/or SPG+SBG therapies were included. Search strategy found 2,250 titles. Among these, 148 (after title analysis) and 39 (after abstract analysis) papers were considered to be relevant. Finally, 19 studies were selected after full-text analysis. No article had a direct comparison between the therapies. Five SPG and 14 SPG+SBG studies presented experimental groups with these respective regimens and were descriptively analyzed while most of the results were only presented graphically. The results showed that both SPG and SPG+SBG protocols of PMP determined stability in the microbiological results along time. Nevertheless, new studies comparing these interventions in PMP are needed, especially if the limitations herein discussed could be better controlled.

Lack of adjunctive effect of 0.1% sodium hypochlorite mouthwash combined to full-mouth ultrasonic debridement on supragingival plaque, gingival inflammation, and subgingival microbiota: A randomized placebo-controlled 6-month trial

To test the adjunctive effect of 0.1% sodium hypochlorite (NaOCl) mouthwash combined to full‐mouth ultrasonic debridement (FMUD) on reducing supragingival plaque, gingival inflammation, and microbial pathogens. In this 6‐month double‐blinded randomized clinical trial, individuals with gingivitis were assigned to test (n = 16) or placebo group (n = 16) and received FMUD followed by rinsing with 0.1% NaOCl (test) or distilled water (placebo), respectively, twice a day for 1 month. Full‐mouth periodontal examination was performed at baseline, 1, 3, and 6 months posttherapy, and subgingival plaque samples were obtained at the same time points and analysed for their composition by checkerboard. Differences between groups over time were examined by Student t test, Mann–Whitney, generalized linear model, and Friedman and chi‐square tests. Both therapeutic protocols resulted in significant clinical improvement in periodontal parameters over time, except for probing depth and attachment level, which had a slight mean increase of 0.2 mm (p < .01). No significant differences between groups were observed for any clinical parameter (p > .05). Most species (>65%) decreased similarly in levels in both groups over time. Significant reductions in the microbial complexes were seen mainly at 1 and 3 months, but they returned to baseline levels in both groups, except for the red and yellow complexes, and other oral species, which were kept in low levels at 6 months (p < .05). A 0.1% NaOCl mouthwash did not provide additional benefits to FMUD in reducing supragingival plaque, gingivitis, and/or microbial pathogens.

Systemic antibiotics in the treatment of periodontitis

Despite the fact that several clinical studies have shown additional benefits when certain systemic antibiotics are used as adjuncts to periodontal treatment, clear guidelines for the use of these agents in the clinical practice are not yet available. Basic questions concerning the use of systemic antibiotics to treat periodontitis remain unanswered, such as: which drug(s) should be used; which patients would most benefit from treatment; which are the most effective protocols (i.e. doses and durations); and in which phase of the mechanical therapy should the drug(s) be administered? Although not all of those questions have been directly addressed by controlled randomized clinical trials, recent concepts related to the ecology of periodontal diseases, as well as the major advances in laboratory and clinical research methods that have occurred in the past decade, have significantly broadened our knowledge in this field. This article endeavored to provide a 'state of the art' overview on the use of systemic antibiotics in the treatment of periodontitis, based on the most recent literature on the topic as well as on a compilation of data from studies conducted at the Center of Clinical Trials at Guarulhos University (São Paulo, Brazil) from 2002 to 2012.

Antibiotic susceptibility of periodontal Streptococcus constellatus and Streptococcus intermedius clinical isolates

BACKGROUND

Streptococcus constellatus and Streptococcus intermedius in subgingival dental plaque biofilms may contribute to forms of periodontitis that resist treatment with conventional mechanical root debridement/surgical procedures and may additionally participate in some extraoral infections. Because systemic antibiotics are often used in these clinical situations, and little is known of the antibiotic susceptibility of subgingival isolates of these two bacterial species, this study determined the in vitro susceptibility to six antibiotics of fresh S. constellatus and S. intermedius clinical isolates from human periodontitis lesions.

METHODS

A total of 33 S. constellatus and 17 S. intermedius subgingival strains, each recovered from separate patients with severe chronic periodontitis (n = 50) before treatment, were subjected to antibiotic gradient strip susceptibility testing with amoxicillin, azithromycin, clindamycin, ciprofloxacin, and doxycycline on blood-supplemented Mueller-Hinton agar and to the inhibitory effects of metronidazole at 16 mg/L in an enriched Brucella blood agar dilution assay. Clinical and Laboratory Standards Institute and European Committee on Antimicrobial Susceptibility Testing interpretative standards were used to assess the results.

RESULTS

Clindamycin was the most active antibiotic against S. constellatus (minimum inhibitory concentration at 90% [MIC90] 0.25 mg/L), and amoxicillin was most active against S. intermedius (MIC90 0.125 mg/L). A total of 30% of the S. constellatus and S. intermedius clinical isolates were resistant in vitro to doxycycline, 98% were only intermediate in susceptibility to ciprofloxacin, and 90% were resistant to metronidazole at 16 mg/L.

CONCLUSION

Subgingival S. constellatus and S. intermedius exhibited variable antibiotic susceptibility profiles, potentially complicating empirical selection of periodontitis antibiotic therapy in patients who are species positive.

Efficacy of curcumin as an adjunct to scaling and root planning in chronic periodontitis patients: A clinical and microbiological study

Background and Objectives:

Curcumin is a naturally occurring anti-inflammatory agent with various biologic and medicinal properties. Its therapeutic applications have been studied in a variety of conditions, but only few studies have evaluated the efficacy of curcumin as local drug delivery agent and in the treatment of periodontitis. The present study was to evaluate the efficacy of the adjunctive use of curcumin with scaling/root planing as compared with scaling/root planing alone in the treatment of the chronic periodontitis.

Materials and Methods:

Thirty patients with two sites in the contralateral quadrants having probing pocket depths (PPDs) of ≥5 mm were selected. Full mouth scaling and root planing (SRP) was performed followed by application of curcumin gel on a single side. Assessment of plaque index (PI), gingival index (GI), PPD, and clinical attachment levels (CALs) were done at baseline and at 4^th week. Microbiologic assessment with polymerase chain reaction was done for Porphyromonas gingivalis, Tanerella forsythia, and Treponema denticola by collection of plaque samples.

Results:

The results revealed that there was a reduction in PI, GI, probing depth, CAL, and microbiologic parameters in test sites following SRP and curcumin gel application, when compared with SRP alone in control group.

Conclusion:

The local application of curcumin in conjunction with scaling and root planing have showed improvement in periodontal parameters and has a beneficial effect in patients with chronic periodontitis.

Supragingival biofilm control and systemic inflammation in patients with type 2 diabetes mellitus

The objective of this study was to evaluate the effect of strict supragingival biofilm control on serum inflammatory markers and on periodontal clinical parameters in type 2 diabetes mellitus (T2DM) patients with chronic severe periodontitis. Twenty-four individuals with T2DM and periodontitis were randomly allocated to two treatment groups. The supragingival therapy group (ST, n = 12) received supragingival scaling, whereas the intensive therapy group (IT, n = 12) underwent supra- and subgingival scaling, as well as root planing. Patients from both groups received professional oral hygiene instructions every month. Data regarding visible plaque index (VPI), gingival bleeding index (GBI), bleeding on probing (BOP), probing pocket depth (PPD), clinical attachment level (CAL), serum levels of interleukin (IL)-6, IL-17A, IL-8, tumor necrosis factor α (TNF-α), monocyte chemoattractant protein (MCP)-1 enzyme-linked immunosorbent assay (ELISA), and glycated hemoglobin (HbA1c) levels were obtained at baseline and at 6 months post-therapy. Both therapies resulted in the improvement of almost all clinical periodontal parameters (p < 0.05). There were no differences in TNF-α, IL-8, IL-17A and HbA1c levels in either group (p > 0.05), between the two periods. However, MCP-1 levels were significantly reduced in both the ST (p = 0.034) and the IT (p = 0.016) groups, whereas the serum IL-6 levels were significantly reduced only in the IT group (p = 0.001). Strict control of supragingival biofilm has a limited effect on systemic inflammatory markers, and a moderate effect on periodontal clinical parameters.

Long-term evaluation of the antimicrobial susceptibility and microbial profile of subgingival biofilms in individuals with aggressive periodontitis

This study evaluates the antimicrobial susceptibility and composition of subgingival biofilms in generalized aggressive periodontitis (GAP) patients treated using mechanical/antimicrobial therapies, including chlorhexidine (CHX), amoxicillin (AMX) and metronidazole (MET). GAP patients allocated to the placebo (C, n = 15) or test group (T, n = 16) received full-mouth disinfection with CHX, scaling and root planning, and systemic AMX (500 mg)/MET (250 mg) or placebos. Subgingival plaque samples were obtained at baseline, 3, 6, 9 and 12 months post-therapy from 3–4 periodontal pockets, and the samples were pooled and cultivated under anaerobic conditions. The minimum inhibitory concentrations (MICs) of AMX, MET and CHX were assessed using the microdilution method. Bacterial species present in the cultivated biofilm were identified by checkerboard DNA-DNA hybridization. At baseline, no differences in the MICs between groups were observed for the 3 antimicrobials. In the T group, significant increases in the MICs of CHX (p < 0.05) and AMX (p < 0.01) were detected during the first 3 months; however, the MIC of MET decreased at 12 months (p < 0.05). For several species, the MICs significantly changed over time in both groups, i.e., Streptococci MICs tended to increase, while for several periodontal pathogens, the MICs diminished. A transitory increase in the MIC of the subgingival biofilm to AMX and CHX was observed in GAP patients treated using enhanced mechanical therapy with topical CHX and systemic AMX/MET. Both protocols presented limited effects on the cultivable subgingival microbiota.

S-nitrosoglutathione accelerates recovery from 5-fluorouracil-induced oral mucositis

Introduction

Mucositis induced by anti-neoplastic drugs is an important, dose-limiting and costly side-effect of cancer therapy.

Aim

To evaluate the effect of the topical application of S-nitrosoglutathione (GSNO), a nitric oxide donor, on 5-fluorouracil (5-FU)-induced oral mucositis in hamsters.

Materials and Methods

Oral mucositis was induced in male hamsters by two intraperitoneal administrations of 5-FU on the first and second days of the experiment (60 and 40 mg/kg, respectively) followed by mechanical trauma on the fourth day. Animals received saline, HPMC or HPMC/GSNO (0.1, 0.5 or 2.0 mM) 1 h prior to the 5-FU injection and twice a day for 10 or 14 days. Samples of cheek pouches were harvested for: histopathological analysis, TNF-α and IL-1β levels, immunohistochemical staining for iNOS, TNF-α, IL-1β, Ki67 and TGF-β RII and a TUNEL assay. The presence and levels of 39 bacterial taxa were analyzed using the Checkerboard DNA-DNA hybridization method. The profiles of NO released from the HPMC/GSNO formulations were characterized using chemiluminescence.

Results

The HPMC/GSNO formulations were found to provide sustained release of NO for more than 4 h at concentration-dependent rates of 14 to 80 nmol/mL/h. Treatment with HPMC/GSNO (0.5 mM) significantly reduced mucosal damage, inflammatory alterations and cell death associated with 5-FU-induced oral mucositis on day 14 but not on day 10. HPMC/GSNO administration also reversed the inhibitory effect of 5-FU on cell proliferation on day 14. In addition, we observed that the chemotherapy significantly increased the levels and/or prevalence of several bacterial species.

Conclusion

Topical HPMC/GSNO accelerates mucosal recovery, reduces inflammatory parameters, speeds up re-epithelization and decreases levels of periodontopathic species in mucosal ulcers.

Effects of nonsurgical periodontal therapy on clinical response, microbiological profile, and glycemic control in Malaysian subjects with type 1 diabetes

The association between diabetes mellitus and chronic periodontal disease has long been established. Most of the researches linking these two very common chronic diseases were based on type 2 diabetes mellitus and chronic periodontal disease. However, this study was conducted to investigate the association between type 1 diabetes and chronic periodontal disease in Malaysian subjects. Forty-one Malaysian subjects, of which 20 subjects were type 1 diabetics and with chronic periodontal disease (test group) and 21 subjects with only chronic periodontal disease (control group), were included in the study. Periodontal parameters and plaque samples for microbiological evaluation were done at baseline, 2 and 3 months after nonsurgical periodontal therapy. Blood samples were taken from only the test group and evaluated for HbA1c at baseline and 3 months after periodontal therapy. There were no statistically significant difference in periodontal parameters between groups (P>0.05) and no significant improvement in the level of HbA1c in the test group. Microbiological studies indicated that there were significant reductions in the levels of the tested pathogens in both groups. The results of our study were similar to the findings of several other studies that had been done previously.

Microbiological changes after periodontal therapy in diabetic patients with inadequate metabolic control

The present study investigated the effect of non-surgical periodontal treatment (SRP) on the composition of the subgingival microbiota of chronic periodontitis (CP) in individuals with type 2 diabetes (DM2) with inadequate metabolic control and in systemically healthy (SH) individuals. Forty individuals (20 DM2 and 20 SH) with CP underwent full-mouth periodontal examination. Subgingival plaque was sampled from 4 deep sites of each individual and tested for mean prevalence and counts of 45 bacterial taxa by the checkerboard method. Clinical and microbiological assessments were performed before and 3 months after SRP. At baseline, those in the DM2 group presented a significantly higher percentage of sites with visible plaque and bleeding on probing compared with those in the SH group (p<0.01). Those in the DM2 group presented significantly higher levels of C. rectus and P. gingivalis, and lower prevalence of P. micra and S. anginosus, compared with those in the SH group (p≤0.001). At the 3-month visit, both groups showed a significant improvement in all clinical parameters (p<0.01). Those in the DM2 group showed significantly higher prevalence and/or levels of A. gerencseriae, A. naeslundii I, A. oris, A. odontolyticus, C. sputigena, F. periodonticum, and G. morbillorum compared with those in the SH group (p≤0.001). However, those in the DM2 group showed a significant reduction in the levels of P. intermedia, P. gingivalis, T. forsythia, and T. denticola (p≤0.001) over time. Those in the SRP group showed improved periodontal status and reduced levels of putative periodontal pathogens at 3 months' evaluation compared with those in the DM2 group with inadequate metabolic control.

Short-term microbiological effects of scaling and root planing and essential-oils mouthwash in Chinese adults

OBJECTIVE

To assess the short-term effect of scaling and root planing (SRP) and essential-oils mouthwash on the levels of specific bacteria in Chinese adults.

METHODS

Fifty Chinese adults with chronic periodontitis were randomly assigned to full-mouth SRP or a 7-d essential-oils mouthwash regimen. In addition, 22 periodontally healthy adults used essential-oils mouthwash for 7 d. Clinical examination and plaque/saliva sampling were performed at baseline and on Day 7. Quantitative real-time polymerase chain reaction (PCR) was used to measure Aggregatibacter actinomycetemcomitans (Aa), Fusobacterium nucleatum (Fn), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), and total bacterial loads in saliva, supra- and sub-gingival plaque samples.

RESULTS

The detection frequencies of four tested species remained unchanged after either treatment. However, the bacterial loads of Fn, Pg, and Pi were significantly reduced by SRP; the mean reduction of bacterial counts in saliva ranged from 52.2% to 62.5% (p<0.01), in supragingival plaque from 68.2% to 81.0% (p<0.05), and in subgingival plaque from 67.9% to 93.0% (p<0.01). Total bacterial loads were reduced after SRP in supra- and sub-gingival plaque (p<0.05). Essential-oils mouthwash reduced Fn levels in supragingival plaque by a mean of 53.2%, and reduced total bacterial loads in supra- and sub-gingival plaque (p<0.01). In subgingival plaque from periodontal patients, Pg and Pi reductions were high after SRP compared to essential-oils mouthwash (93.0% vs. 37.7% and 87.0% vs. 21.0%, p<0.05). No significant bacterial reduction was observed in periodontally healthy subjects using essential-oils mouthwash.

CONCLUSIONS

SRP and essential-oils mouthwash both have an impact on saliva and gingival plaque flora in Chinese periodontitis patients in 7 d, with greater microbiological improvement by SRP.

Molecular detection of Aggregatibacter actinomycetemcomitans on metallic brackets by the checkerboard DNA-DNA hybridization technique

INTRODUCTION

The purpose of this randomized clinical study was to evaluate the presence of the periodontal pathogen Aggregatibacter actinomycetemcomitans on metallic brackets and the effectiveness of a 0.12% chlorhexidine digluconate mouthwash in inhibiting this microorganism.

METHODS

The study involved 35 patients of both sexes having orthodontic treatment with fixed appliances between the ages of 14 and 22 years, randomized into 2 groups: experimental (n = 17) and control (n = 18). Two new metallic brackets were placed on the patients' premolars, and the subjects rinsed with a solution of 0.12% chlorhexidine digluconate or a placebo solution twice a week for 30 days. After that, the brackets were removed and underwent microbiologic analysis with the checkerboard DNA-DNA hybridization technique. Data were analyzed by using the Student t, Fisher exact, and Mann-Whitney tests at the significance level of 5%.

RESULTS

The results showed that A actinomycetemcomitans was present in all brackets from the subjects in the control group vs 83% of the subjects who rinsed with chlorhexidine digluconate (P <0.0001). There were also significantly lower levels of this species in the chlorhexidine digluconate group compared with the control group (P = 0.0003).

CONCLUSIONS

We concluded that 0.12% chlorhexidine digluconate rinsing, twice a week for 30 days during orthodontic treatment, is effective in reducing the presence and levels of A actinomycetemcomitans on metallic brackets.

Microbial sampling process can change results of microbiological analysis in periodontitis diagnosis. A minireview

This minireview aims to verify the supposition that the microbial sampling process can change results of microbiological analysis in periodontitis diagnosis. The literature search via Pubmed yielded 52 appropriate articles for analysis. Of which 38% (20/52) described that the sampling sites were isolated from saliva, whereas 62% (32/52) did not. Also, 29% (15/52) declared that the microbial sampling was performed before probing pocket depth (PPD), whereas 71% (37/52) did not. Comparison of the results of microbiological analysis in these studies showed that the bacteria most frequently detected in periodontal pockets was variable. Therefore, a sampling process that includes both the microbial sample being taken before PPD and saliva isolation of the sampling sites is needed to ensure the accuracy of microbiological analysis in periodontitis diagnosis.

Clinical and microbiological changes after minimally invasive therapeutic approaches in intrabony defects: a 12-month follow-up

OBJECTIVES

This 12-month randomized, controlled trial evaluated the clinical effects and microbiological changes of minimally invasive nonsurgical and surgical approaches for the therapy of intrabony defects.

MATERIALS AND METHODS

Twenty-nine subjects with intrabony defects in single-rooted tooth were randomly assigned to; (1) minimally invasive nonsurgical technique (MINST) or (2) minimally invasive surgical technique (MIST). Quantities of Aggregatibacter actinomycetemcomitans, Tannerella forsythia, and Porphyromonas gingivalis, determined by using real-time PCR, were evaluated at baseline, 3, 6, and 12 months after the treatments. Clinical recordings--probing depth (PD), position of the gingival margin (PGM), and relative clinical attachment level (RCAL)--were obtained at baseline and 12 months post-therapy. The primary outcome variable of the study was RCAL.

RESULTS

Both treatment modalities resulted in an improvement in all clinical recordings, with significant PD reductions (p < 0.05), RCAL gains (p < 0.05), and no change in the PGM (p > 0.05) after 12 months in both MINST and MIST groups. No clinical differences were observed between groups (p > 0.05). Regarding the microbiological outcomes, at the re-examinations, a significant decrease was observed for T. forsythia and P. gingivalis when compared with baseline (p < 0.05) for both treatments. The amount of A. actinomycetemcomitans did not reduced decrease throughout the study (p > 0.05). Intergroup differences in the microbiological assay were not found at any time point (p > 0.05).

CONCLUSIONS

Both MINST and MIST provided comparable clinical results and microbiological changes in the treatment of intrabony defects over 12 months follow-up.

CLINICAL RELEVANCE

This randomized, controlled, parallel trial revealed that both therapeutic modalities may promote clinical and microbiological benefits at 12 months post-therapy.

Adsorption of chlorhexidine on synthetic hydroxyapatite and in vitro biological activity

The kinetic of chlorhexidine digluconate (CHXDG) uptake from aqueous solution by hydroxyapatite (HA) was investigated by ultraviolet (UV) analysis performed in HA powder (UV-solid) after the CHX adsorption. Adsorption isotherm of chlorhexidine (CHX) uptake was modeled by a combination of Languimir and Langmuir-Freundlich mechanisms. Strong molecule-molecule interactions and positive cooperativity predominated in the surface when CHX concentration was above 8.6 μg(CHX)/mg(HA). UV-solid spectra (shape, intensity and band position) of CHX bound to HA revealed that long-range molecular structures, such as aggregates or micelles, started to be formed at low CHX concentrations (1.52 μg(CHX)/mg(HA)) and predominated at high concentrations. Grazing-incidence X-ray diffraction (GIXRD) analysis from synchrotron radiation discarded the formation of crystalline structures on HA surface or precipitation of CHX crystalline salts, as suggested in previous works. The effect of the HA/CHX association on HA in vitro bioactivity, cytotoxicity and CHX antimicrobial activity was evaluated. It was shown that CHX did not inhibit the precipitation of a poorly crystalline apatite at HA/CHX surface after soaking in simulating body fluid (SBF). Cell viability studies after exposure to extracts of HA and HA/CHX showed that both biomaterials did not present significant in vitro toxicity. Moreover, HA/CHX inhibited Enterococcus faecalis growth for up to 6 days, revealing that binding to HA did not affect antimicrobial activity of CHX and reduced bacterial adhesion. These results suggested that HA/CHX association could result in a potential adjuvant antimicrobial system for clinical use.

Prospective clinical study evaluating the long-time adjunctive use of chlorhexidine after one-stage full-mouth SRP

OBJECTIVES

Scaling and root planing are the causal procedure in the treatment of periodontitis. Many attempts have been made to improve the outcome. The aim of this study was to verify the influence of the extended use of chlorhexidine after one-stage full-mouth (FM) SRP in patients with chronic periodontitis on the clinical outcome after 3 months.

METHODS

Eighty-one patients with pockets > or =5 mm were treated by FM. All patients rinsed additionally with 0.2% chlorhexidine (CHX) twice daily over 3 months. Plaque index, bleeding on probing, probing depth (PD) and clinical attachment level (CAL) were recorded at baseline and after 1 and 3 months.

RESULTS

In the test group, all variables were significantly improved after 1 and 3 months. Mean reduction of PD and CAL gain was 2.25 +/- 1.08 and 1.67 +/- 1.08 after 1 and 2.99 +/- 1.11 and 2.33 +/- 1.31 after 3 months respectively.

CONCLUSIONS

Over 3 months of extended use of CHX mouth rinse after SRP showed slightly but statistically significant better results.

Use of the DNA Checkerboard hybridization method for detection and quantitation of Candida species in oral microbiota

The DNA Checkerboard method enables the simultaneous identification of distinct microorganisms in a large number of samples and employs up to 45 whole genomic DNA probes to gram-negative and gram-positive bacterial species present in subgingival biofilms. Collectively, they account for 55%-60% of the bacteria in subgingival biofilms. In this study, we present the DNA Checkerboard hybridization as an alternative method for the detection and quantitation of Candida species in oral cavities. Our results reveal that DNA Checkerboard is sensitive enough and constitutes a powerful and appropriate method for detecting and quantifying Candida species found in the oral cavity.

The use of fluorescein for labeling genomic probes in the checkerboard DNA–DNA hybridization method

Molecular methods that permit the simultaneous detection and quantification of a large number of microbial species are currently employed in the evaluation of complex ecosystems. The checkerboard DNA-DNA hybridization technique enables the simultaneous identification of distinct bacterial species in a large number of dental samples. The original technique employed digoxigenin-labeled whole genomic DNA probes which were detected by chemiluminescence. In this study, we present an alternative protocol for labeling and detecting whole genomic DNA probes in the Checkerboard DNA-DNA hybridization method. Whole genomic DNA was extracted from five bacterial species and labeled with fluorescein. The fluorescein labeled whole genomic DNA probes were hybridized against whole genomic DNA or subgingival plaque samples in a checkerboard hybridization format, followed by chemiluminescent detection. Our results reveal that fluorescein is a viable and adequate alternative labeling reagent to be employed in the checkerboard DNA-DNA hybridization technique.

Manual and electronic probing of the periodontal attachment level in untreated periodontitis: a systematic review

OBJECTIVE

A systematic review of clinical trials has been performed to evaluate the reproducibility of manual (MP) and electronic probes (EP) in the measurement of clinical periodontal attachment level (AL) in untreated periodontitis subjects.

METHODS

Systematic electronic (PubMed Medline and Latin American and Caribbean Health Science--LILACS literature databases) and hand searches (English, Spanish and Portuguese languages; search terms "periodontitis diagnosis", "clinical attachment level measurements", "clinical attachment level detection", "clinical diagnosis of periodontitis", "manual probe", "electronic probe", "periodontitis or periodontal disease or attachment level or clinical attachment level") were performed to identify clinical trials involving CAL measurements, MP and EP in untreated periodontitis subjects. Quality and external validity were determined for selected studies.

RESULTS

The initial search identified 37 articles. Ten studies met the initial eligibility, but eight were excluded after thorough analysis. The results from those two selected studies showed that the average variance and the absolute mean difference of CAL measurements for both types of probes cannot be considered different.

CONCLUSION

"Based on this systematic review, MP and EP probes showed a tendency to have similar reliability in the measurement of CAL in untreated periodontitis subjects when used by a calibrated examiner. However, this finding is not supported by strong evidence.

Etiological analysis of initial colonization of periodontal pathogens in oral cavity

It is unclear when the initial colonization by periodontal pathogens occurs in the oral cavity. Therefore, we report here the association between specific age groups and the time when the initial colonization by periodontal pathogens occurs in the oral cavity in such groups. Findings are based on an epidemiological analysis of the prevalence of five periodontal pathogens in the oral cavities of a wide range of age populations, from newborn to elderly, who were randomly selected in a geographic region of Brazil. These periodontal pathogens include Campylobacter rectus, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Prevotella intermedia, and Tannerella forsythia and were analyzed in the bacterial samples isolated from gingival sulcus, the dorsum of the tongue, and cheek mucosa of diverse age groups, using a bacterial DNA-specific PCR method. Results indicated that there are distinct age-related groups where initial colonization by the five periodontal pathogens examined in this study can be detected and that the presence of teeth is a permissive factor for colonization by P. gingivalis, P. intermedia, and T. forsythia. Although it remains unclear exactly how or when target pathogens colonize healthy subjects, an understanding of age-related groups does provide a potentially useful tool in the early detection and prevention of periodontitis in healthy individuals.

Scaling and root planing and chlorhexidine mouthrinses in the treatment of chronic periodontitis: a randomized, placebo-controlled clinical trial

OBJECTIVE

Evaluation of the clinical and microbiological effects of scaling and root planing (SRP) alone or in combination with 0.12% chlorhexidine (CHX) rinsing.

METHODS

A blind, placebo-controlled, parallel-design, randomized clinical trial was conducted in 29 subjects with chronic periodontitis. Subjects were assigned to two therapeutic groups: control (SRP+placebo) and test (SRP+CHX during and up to 42 days post-therapy). Clinical and microbiological [N-benzoyl-dl-arginine-2-naphthylamide (BANA test)] examinations were performed at baseline, 42 and 63 days post-therapy.

RESULTS

Initially, intermediate sites (4-6 mm) in the test group showed less plaque accumulation, gingival bleeding, bleeding on probing and a greater reduction in attachment level and probing depth (PD) at 63 days after treatment. The initially deep sites (>6 mm) in the CHX group also showed a better reduction in plaque accumulation and in PD compared with the control group. Both therapies led to a microbiological improvement; however, the test subjects showed a higher frequency of BANA-negative sites after treatment, which was sustained over time (p<0.001). At 63 days, the control group presented 25 BANA-negative sites and 65 positive sites, and the test group 58 and 26, respectively.

CONCLUSION

The combination of CHX rinses and SRP leads to clinical benefits and to a better reduction in BANA-positive species.

Changes in the subgingival microbiota and periodontal parameters before and 3 months after bracket placement

INTRODUCTION

Dental plaque is organized in a biofilm complex that provides protection and nutrients for periodontopathic bacteria. Several factors can affect microbial colonization, including restorations and orthodontic brackets. The aim of this study was to investigate changes in subgingival microbiota and clinical parameters before and after bracket placement.

METHODS

Clinical parameters and subgingival microbial samples were collected from 30 patients before and after bracket placement. Thirty additional patients with no orthodontic treatment served as controls. Samples were cultured and analyzed for periodontopathic and superinfecting bacteria. A descriptive analysis was conducted, and chi-square, Student t, Wilcoxon matched, and Mann Whitney rank sum tests were used to test for differences between groups (P < or=.05).

RESULTS

No changes in probing depth or clinical attachment level were observed, but scores for bleeding on probing, plaque index, and gingival index increased after bracket placement (P < or =.05). Porphyromonas gingivalis, Prevotella intermedia/Prevotella nigrescens, Tannerella forsythia, and Fusobacterium species were elevated in the experimental group after bracket placement compared with the control group (P < or =.01). Superinfecting microorganisms such as Enterobacter cloacae, Klebsiella oxytoca, Klebsiella pneumoniae, and Serratia marcescens were also found.

CONCLUSIONS

Bracket placement influences the accumulation of plaque and the colonization of important periodontopathic and superinfecting bacteria, resulting in more inflammation and bleeding. Special attention should be paid to oral hygiene methods in orthodontic patients.