Microbiological goals of periodontal therapy

Effect of an intensive antiplaque regimen on microbiome outcomes after nonsurgical periodontal therapy

BACKGROUND

It has been well documented that periodontal treatment decreases the levels of certain disease-associated species in subgingival plaque. Few studies, however, investigate to which extent periodontal therapy restores a health-like subgingival community. Here, we conducted a secondary analysis to evaluate microbiome outcomes of nonsurgical periodontal therapy alone or followed by an intensive antiplaque regimen, analyzing microbiome trajectories at the community level with respect to health.

METHODS

Eighty-six subjects with periodontitis stages II/III were evaluated at baseline and 6 months after receiving scaling and root planing alone (SRP, n = 41) or followed by an antiplaque regimen consisting of use of 0.12% chlorhexidine for 3 months and interdental cleaners for 6 months (SRP + P + S, n = 45). Thirty periodontally healthy subjects served as reference. The subgingival microbiome was characterized by 16S rRNA gene sequencing, and longitudinal within-subject changes were quantified with respect to a healthy plane (HPL) modeled from the reference group.

RESULTS

Evaluation of individual microbiome trajectories showed that only the SRP + P + S group had a statistically significant reduction in distance to the HPL. However, responses were variable in both groups, with only a fraction of individuals changing in the direction of health. Random forest analysis revealed baseline microbiome composition as a greater predictor of microbiome response than type of treatment rendered.

CONCLUSION

An adjunct antiplaque regimen resulted in a greater approximation of the microbiome to the healthy state. However, responses varied greatly among subjects highlighting the need for robust and personalized approaches to restore eubiosis.

PLAIN LANGUAGE SUMMARY

This study looked at how different treatments for gum disease change the bacteria in the gums of people with moderate to severe gum problems. Eighty-six people received standard gum treatments, and some also used a mouthwash and special tools to clean between their teeth at home. After 6 months, more people in the group that added the extra cleaning steps had healthier bacteria in their gums than people who received the standard treatment. However, not everyone responded the same way. The study found that the types of bacteria someone had at the start were better at predicting how well the treatment would work, more than the type of treatment itself. This means gum disease treatments may need to be personalized for better results.

Periodontal Treatment to Improve General Health and Manage Systemic Diseases

Periodontitis is increasingly recognized for its role in overall health and its associations with systemic conditions. Shared etiological factors, including microbiological, immunological, genetic, and environmental influences, have prompted interest in the potential impact of periodontal therapy on broader health outcomes. The oral microbiome plays a key role in the pathogenesis of periodontitis, with microbial imbalances (dysbiosis) contributing to inflammation and systemic disease progression. Additionally, immune responses to periodontal infection, such as chronic inflammation and dysregulated immune activity, are central to linking periodontitis with conditions like diabetes, cardiovascular disease, and autoimmune disorders. This chapter explores the connections between periodontal treatment and systemic diseases, such as diabetes, rheumatoid arthritis, cardiovascular disease, chronic kidney disease, Alzheimer's disease, digestive disorders, and respiratory disease. It also reviews the current research on the mechanisms, including microbial and immune factors, that underlie these associations. By emphasizing the role of periodontal health, the oral microbiome, and immune regulation in disease prevention and management, this chapter underscores the importance of integrated healthcare approaches to improve patient outcomes.

Chamomile Tincture and Lidocaine Hydrochloride Gel Ameliorates Periodontitis: A Preclinical Study

Background/Objectives: Periodontitis is a common oral disease marked by gingival inflammation and alveolar bone loss. This study evaluated the efficacy of chamomile tincture and lidocaine hydrochloride (CLH) gel in mitigating periodontal inflammation and bone loss and uncovered the molecular mechanisms involved, both in vitro and in vivo. Methods: A periodontitis model was induced in Sprague Dawley rats by ligating the mandibular first molars. Sixty rats were divided into four groups: control (C), periodontitis (PD), periodontitis + CLH gel once daily (G1), and periodontitis + CLH gel thrice daily (G3). Clinical, micro-computed tomography (micro-CT), biological, and histological evaluations were performed, focusing on osteoclastogenesis, osteogenesis, and inflammatory cytokine production. The effect of CLH gel on inflammatory responses in RAW264.7 cells was also assessed through co-culture assays under Porphyromonas gingivalis (P. gingivalis) infection, with RNA-sequencing, qPCR, and Western blot analyses to explore underlying mechanisms. Results: CLH gel significantly reduced gingival and systemic inflammation and mitigated bone loss by enhancing the bone volume to tissue volume ratio and trabecular thickness via the RANKL/OPG axis in rats. The G3 group showed marked reductions in osteoclasts and increases in osterix-positive cells compared to other groups. In vitro, CLH gel reduced the inflammatory phenotype of macrophages in the periodontitis microenvironment by modulating Type II interferon (IFN-γ) networks. Conclusions: CLH gel reduced inflammation and bone loss in rat periodontitis, promoting osteogenesis and inhibiting osteoclastogenesis. It also suppressed macrophage inflammation via Type II interferon networks under P. gingivalis stimulation. These findings suggest that CLH gel has potential as an adjunctive therapy for periodontitis.

Expert consensus on the diagnosis and therapy of endo-periodontal lesions

Endo-periodontal lesions (EPLs) involve both the periodontium and pulp tissue and have complicated etiologies and pathogenic mechanisms, including unique anatomical and microbiological characteristics and multiple contributing factors. This etiological complexity leads to difficulties in determining patient prognosis, posing great challenges in clinical practice. Furthermore, EPL-affected teeth require multidisciplinary therapy, including periodontal therapy, endodontic therapy and others, but there is still much debate about the appropriate timing of periodontal therapy and root canal therapy. By compiling the most recent findings on the etiology, pathogenesis, clinical characteristics, diagnosis, therapy, and prognosis of EPL-affected teeth, this consensus sought to support clinicians in making the best possible treatment decisions based on both biological and clinical evidence.

Evaluation of a Novel Immunochromatographic Device for Detecting Porphyromonas gingivalis in Patients with Periodontal Disease

Porphyromonas gingivalis is the most pathogenic periodontal bacterium in the world. Recently, P. gingivalis has been considered responsible for dysbiosis during the development of periodontitis. This study aimed to evaluate a novel immunochromatographic device using monoclonal antibodies against P. gingivalis in subgingival plaques. A total of 72 patients with chronic periodontitis and 53 periodontally healthy volunteers underwent clinical and microbiological examinations. Subgingival plaque samples were analyzed for the presence of P. gingivalis and compared using real-time polymerase chain reaction (PCR). In the periodontitis group, a significant positive correlation was observed between the test device scores and the real-time PCR results. The specificity, positive predictive value, negative predictive value, and accuracy of the test device for P. gingivalis, as determined by real-time PCR, were 98%, 94%, 89%, and 90%, respectively. There were significant differences in bacterial counts by real-time PCR among the groups with different ranges of device scores. Additionally, there was a significant positive correlation between the device scores for P. gingivalis and periodontal parameters. These results suggest that this novel immunochromatographic device can be effectively used for rapid detection and semi-quantification of P. gingivalis in subgingival plaques.

Adjunctive antimicrobial photodynamic therapy for treating periodontal and peri-implant diseases

BACKGROUND

Periodontitis and peri-implant diseases are chronic inflammatory conditions occurring in the mouth. Left untreated, periodontitis progressively destroys the tooth-supporting apparatus. Peri-implant diseases occur in tissues around dental implants and are characterised by inflammation in the peri-implant mucosa and subsequent progressive loss of supporting bone. Treatment aims to clean the pockets around teeth or dental implants and prevent damage to surrounding soft tissue and bone, including improvement of oral hygiene, risk factor control (e.g. encouraging cessation of smoking) and surgical interventions. The key aspect of standard non-surgical treatment is the removal of the subgingival biofilm using subgingival instrumentation (SI) (also called scaling and root planing). Antimicrobial photodynamic therapy (aPDT) can be used an adjunctive treatment to SI. It uses light energy to kill micro-organisms that have been treated with a light-absorbing photosensitising agent immediately prior to aPDT.

OBJECTIVES

To assess the effects of SI with adjunctive aPDT versus SI alone or with placebo aPDT for periodontitis and peri-implant diseases in adults.

SEARCH METHODS

We searched the Cochrane Oral Health Trials Register, CENTRAL, MEDLINE, Embase, two other databases and two trials registers up to 14 February 2024.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) (both parallel-group and split-mouth design) in participants with a clinical diagnosis of periodontitis, peri-implantitis or peri-implant disease. We compared the adjunctive use of antimicrobial photodynamic therapy (aPDT), in which aPDT was given after subgingival or submucosal instrumentation (SI), versus SI alone or a combination of SI and a placebo aPDT given during the active or supportive phase of therapy.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures, and we used GRADE to assess the certainty of the evidence. We prioritised six outcomes and the measure of change from baseline to six months after treatment: probing pocket depth (PPD), bleeding on probing (BOP), clinical attachment level (CAL), gingival recession (REC), pocket closure and adverse effects related to aPDT. We were also interested in change in bone level (for participants with peri-implantitis), and participant satisfaction and quality of life.

MAIN RESULTS

We included 50 RCTs with 1407 participants. Most studies used a split-mouth study design; only 18 studies used a parallel-group design. Studies were small, ranging from 10 participants to 88. Adjunctive aPDT was given in a single session in 39 studies, in multiple sessions (between two and four sessions) in 11 studies, and one study included both single and multiple sessions. SI was given using hand or power-driven instrumentation (or both), and was carried out prior to adjunctive aPDT. Five studies used placebo aPDT in the control group and we combined these in meta-analyses with studies in which SI alone was used. All studies included high or unclear risks of bias, such as selection bias or performance bias of personnel (when SI was carried out by an operator aware of group allocation). We downgraded the certainty of all the evidence owing to these risks of bias, as well as for unexplained statistical inconsistency in the pooled effect estimates or for imprecision when evidence was derived from very few participants and confidence intervals (CI) indicated possible benefit to both intervention and control groups. Adjunctive aPDT versus SI alone during active treatment of periodontitis (44 studies) We are very uncertain whether adjunctive aPDT during active treatment of periodontitis leads to improvement in any clinical outcomes at six months when compared to SI alone: PPD (mean difference (MD) 0.52 mm, 95% CI 0.31 to 0.74; 15 studies, 452 participants), BOP (MD 5.72%, 95% CI 1.62 to 9.81; 5 studies, 171 studies), CAL (MD 0.44 mm, 95% CI 0.24 to 0.64; 13 studies, 414 participants) and REC (MD 0.00, 95% CI -0.16 to 0.16; 4 studies, 95 participants); very low-certainty evidence. Any apparent differences between adjunctive aPDT and SI alone were not judged to be clinically important. Twenty-four studies (639 participants) observed no adverse effects related to aPDT (moderate-certainty evidence). No studies reported pocket closure at six months, participant satisfaction or quality of life. Adjunctive aPDT versus SI alone during supportive treatment of periodontitis (six studies) We were very uncertain whether adjunctive aPDT during supportive treatment of periodontitis leads to improvement in any clinical outcomes at six months when compared to SI alone: PPD (MD -0.04 mm, 95% CI -0.19 to 0.10; 3 studies, 125 participants), BOP (MD 4.98%, 95% CI -2.51 to 12.46; 3 studies, 127 participants), CAL (MD 0.07 mm, 95% CI -0.26 to 0.40; 2 studies, 85 participants) and REC (MD -0.20 mm, 95% CI -0.48 to 0.08; 1 study, 24 participants); very low-certainty evidence. These findings were all imprecise and included no clinically important benefits for aPDT. Three studies (134 participants) reported adverse effects: a single participant developed an abscess, though it is not evident whether this was related to aPDT, and two studies observed no adverse effects related to aPDT (moderate-certainty evidence). No studies reported pocket closure at six months, participant satisfaction or quality of life.

AUTHORS' CONCLUSIONS

Because the certainty of the evidence is very low, we cannot be sure if adjunctive aPDT leads to improved clinical outcomes during the active or supportive treatment of periodontitis; moreover, results suggest that any improvements may be too small to be clinically important. The certainty of this evidence can only be increased by the inclusion of large, well-conducted RCTs that are appropriately analysed to account for change in outcome over time or within-participant split-mouth study designs (or both). We found no studies including people with peri-implantitis, and only one study including people with peri-implant mucositis, but this very small study reported no data at six months, warranting more evidence for adjunctive aPDT in this population group.

Clinical and microbiological efficacy of intra-pocket application of diode laser in grade C periodontitis: a randomized controlled clinical trial

BACKGROUND

Periodontitis is a microbially induced disease destroying structures anchoring teeth to jaw bones. Although metronidazole in combination with spiramycin is the effective conventional treatment of stage III grade C periodontitis, it has several systemic side effects. Laser therapy is widely used nowadays as an adjunct to scaling and root planing (SRP) to modulate inflammatory host response and eradicate microbes, due to bactericidal and detoxifying effects. Since microbiological analysis is one of the diagnostic methods identifying periodontal risk; our research aimed to investigate the efficacy of intra-pocket application of diode laser (980 nm) versus antibiotic therapy in enhancing clinical and microbiological parameters in stage III grade C periodontitis.

METHODS

A randomized controlled clinical trial was conducted on fifty patients with stage III grade C periodontitis, divided equally into two groups. We managed test group by SRP with intra-pocket application of diode laser (980 nm) and the control group by SRP with systemic antibiotic administration (spiramycin and metronidazole). Then, we measured periodontal pocket depth (PPD) and clinical attachment loss (CAL) for both groups, before treatment (baseline), four and twelve weeks after. Moreover, we collected gingival crevicular fluid from both groups at baseline, four and twelve weeks after treatment and analyzed by real-time polymerase chain reaction to detect the relative count of Aggregatibacter actinomycetemcomitans and Porhyromonas gingivalis.

RESULTS

Compared to baseline, all assessed clinical and microbiological parameters attested improvement at the end of the study period in each group individually with no significant difference between the two studied groups. Although, at twelve weeks, flare up of bacterial levels was detected with systemic antibiotic administration.

CONCLUSION

Laser therapy can be considered as an effective treatment modality in stage III grade C periodontitis, avoiding the systemic antibiotic side effects and solving the recurrence problems due to bacterial resistance by long term usage.

TRIAL REGISTRATION

NCT05222737 retrospectively on 03/02/2022, Clinicaltrial.gov.

Effects of Antimicrobial Photosensitizers of Photodynamic Therapy (PDT) to Treat Periodontitis

Antimicrobial photodynamic therapy or aPDT is an alternative therapeutic approach in which lasers and different photosensitizing agents are used to eradicate periodontopathic bacteria in periodontitis. Periodontitis is a localized infectious disease caused by periodontopathic bacteria and can destroy bones and tissues surrounding and supporting the teeth. The aPDT system has been shown by in vitro studies to have high bactericidal efficacy. It was demonstrated that aPDT has low local toxicity, can speed up dental therapy, and is cost-effective. Several photosensitizers (PSs) are available for each type of light source which did not induce any damage to the patient and are safe. In recent years, significant advances have been made in aPDT as a non-invasive treatment method, especially in treating infections and cancers. Besides, aPDT can be perfectly combined with other treatments. Hence, this survey focused on the effectiveness and mechanism of aPDT of periodontitis by using lasers and the most frequently used antimicrobial PSs such as methylene blue (MB), toluidine blue ortho (TBO), indocyanine green (ICG), malachite green (MG) (Triarylmethanes), erythrosine dyes (ERY) (Xanthenes dyes), rose bengal (RB) (Xanthenes dyes), eosin-Y (Xanthenes dyes), radachlorin group and curcumin. The aPDT with these PSs can reduce pathogenic bacterial loads in periodontitis. Therefore, it is clear that there is a bright future for using aPDT to fight microorganisms causing periodontitis.

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.

Antimicrobial Chemotherapy for Recalcitrant Severe Human Periodontitis

This study evaluated a combined systemic and topical anti-infective periodontal treatment of 35 adults who had experienced ongoing periodontal breakdown following conventional surgical periodontics. The prescribed anti-infective therapy, based on microbiological testing, consisted of a single course of metronidazole plus ciprofloxacin (23 patients), metronidazole plus amoxicillin/clavulanic acid (10 patients), and metronidazole plus ciprofloxacin followed by metronidazole plus amoxicillin/clavulanic acid (2 patients). In addition, the study patients received 0.1% povidone-iodine subgingival disinfection during non-surgical root debridement and daily patient administered oral irrigation with 0.1% sodium hypochlorite. At 1 and 5 years post-treatment, all study patients showed gains in clinical periodontal attachment with no further attachment loss, and significant decreases in pocket probing depth, bleeding on probing, and subgingival temperature. The greatest disease resolution occurred in patients who at baseline harbored predominantly major periodontal pathogens which post-antibiotics became non-detectable and substituted by non-periodontopathic viridans streptococci. The personalized and minimally invasive anti-infective treatment regimen described here controlled periodontitis disease activity and markedly improved the clinical and microbiological status of the refractory periodontitis patients.

Cladophialophora bantiana metabolites are efficient in the larvicidal and ovicidal control of Aedes aegypti, and Culex quinquefasciatus and have low toxicity in zebrafish embryo

Mosquitoes' current insecticide resistance status in available public health insecticides is a serious threat to mosquito control initiatives. Microbe-based control agents provide an alternative to conventional pesticides and insecticides, as they can be more targeted than synthetic insecticides. The present study was focused on identifying and investigating the mosquitocidal potential of Cladophialophora bantiana, an endophytic fungus isolated from Opuntia ficus-indica. The Cladophialophora species was identified through phylogenetic analysis of the rDNA sequence. The isolated fungus was first evaluated for its potential to produce metabolites against Aedes aegpti and Culex quinquefasciatus larvae in the 1-4th instar. The secondary metabolites of mycelium extract were assessed at various test doses (100, 200, 300, 400, and 500 μg/mL) in independent bioassays for each instar of selected mosquito larvae. After 48 h of exposure, A. aegypti expressed LC50 values of 13.069, 18.085, 9.554, and 11.717 μg/mL and LC90 = 25.702, 30.860, 17.275, and 19.601 μg/mL; followed by C. quinquefasciatus LC50 = 14.467, 11.766, 5.934, and 7.589 μg/mL, and LC90 = 29.529, 20.767, 11.192, and 13.296 μg/mL. The mean % of ovicidal bioassay was recorded 120 h after exposure. The hatchability (%) was proportional to mycelia metabolite concentration. The enzymatic level of acetylcholinesterase in fungal mycelial metabolite treated 4th instar larvae indicated a dose-dependent pattern. The GC-MS profile of C. bantiana extracts identified five of the most abundant compounds, namely cyclobutane, trans-3-undecene-1,5-diyne, 1-bromo-2-chloro, propane, 1,2,3-trichloro-2-methyl-, 5,5,10,10-tetrachlorotricyclo, and phenol, which had the killing effect in mosquitoes. Furthermore, the C. bantiana fungus ethyl acetate extracts had a strong larvicidal action on A. aegypti and C. quinquefasciatus. Finally, the toxicity test on zebrafish embryos revealed the induction of malformations only at concentrations above 1 mg/mL. Therefore, our study pioneered evidence that C. bantiana fungal metabolites effectively control A. aegypti and C. qunquefasciastus and show less lethality in zebrafish embryos at concentrations up to 500 μg/mL.

Molecular Iodine Mouthrinse Antimicrobial Activity Against Periodontopathic Bacteria

AIM

This study compared two molecular iodine mouthrinses for their in vitro bactericidal effects against subgingival biofilm bacteria from severe periodontitis patients.

MATERIALS AND METHODS

In a subgingival biofilm eradication assay, dilution aliquots of subgingival microbial specimens from 32 adults with severe periodontitis were mixed in vitro with either a mouthrinse containing 100 parts per million (ppm) molecular iodine (Iorinse®) or one containing 150 ppm molecular iodine (iClean®), followed by mouthrinse neutralization after 60 seconds with 3% sodium thiosulfate. The mixtures, along with unexposed subgingival biofilm aliquots, were inoculated onto enriched Brucella blood agar and incubated anaerobically for 7 days to quantitate total viable bacterial counts and selected red/orange complex periodontal pathogens (Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia/nigrescens, Parvimonas micra, Campylobacter rectus, and Fusobacterium nucleatum).

RESULTS

Both molecular iodine mouthrinses significantly reduced total viable bacterial counts in the subgingival biofilm samples, with iClean® providing significantly greater in vitro suppression than Iorinse®. Both molecular iodine mouthrinses also significantly reduced total red/orange complex periodontal pathogens, with significantly greater suppression also exhibited by iClean®.

CONCLUSION

The molecular iodine mouthrinses exerted marked bactericidal activity in vitro against human subgingival biofilm microbial species, including red/orange complex periodontal pathogens associated with severe periodontitis, with iClean® providing significantly better antimicrobial activity than Iorinse®.

CLINICAL SIGNIFICANCE

These findings suggest potential value of molecular iodine mouthrinses in the treatment and prevention of periodontal diseases.

Metronidazole enhances killing of Porphyromonas gingivalis by human PMNs

Background and objectives

Periodontitis affects the supporting structures of the teeth as a result of the interactions between the subgingival biofilm and the host immune system. Periodontal therapy in severe forms of periodontitis often utilizes antimicrobial agents with some potential to improve host defense responses. In the present study, we investigated the in vitro effect of metronidazole (MTZ) at concentrations achievable in the periodontal pocket on PMN activation and PMN mediated killing of Porphyromonas gingivalis.

Materials and methods

Flow cytometry based assays were used to measure the impact of MTZ on PMN degranulation, neutrophil extracellular trap (NET) formation and myeloperoxidase (MPO) release and phagocytosis in response to the keystone oral pathogen P. gingivalis. Functional assays for PMN mediated killing of P. gingivalis and reactive oxygen species (ROS) production in PMN were also carried out.

Results

We demonstrate that PMNs pretreated with MTZ (2 μg/ml or 50 μg/ml) displayed enhanced killing of P. gingivalis compared to untreated PMNs. At concentrations achieved physiologically in the periodontal pocket, MTZ induced PMN surface expression of two activation markers (CD66 and CD63). MTZ did not alter P. gingivalis-induced NETosis, but suppressed P. gingivalis-induced ROS production and phagocytosis.

Conclusion

MTZ displays a positive interaction with PMNs to potentiate PMN mediated killing of P. gingivalis and may therefore contribute to its beneficial effects in the treatment of periodontitis initiated by P. gingivalis infections including those refractory to conventional treatment.

Oral Microbiota Profile in Patients with Anti-Neutrophil Cytoplasmic Antibody–Associated Vasculitis

Microbiota has been associated with autoimmune diseases, with nasal Staphylococcus aureus being implicated in the pathogenesis of anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV). Little is known about the role of oral microbiota in AAV. In this study, levels of IgG antibodies to 53 oral bacterial species/subspecies were screened using immunoblotting in plasma/serum in pre-symptomatic AAV-individuals (n = 85), matched controls, and established AAV-patients (n = 78). Saliva microbiota from acute-AAV and controls was sequenced from 16s rDNA amplicons. Information on dental status was extracted from a national register. IgG levels against oral bacteria were lower in established AAV versus pre-AAV and controls. Specifically, pre-AAV samples had, compared to controls, a higher abundance of periodontitis-associated species paralleling more signs of periodontitis in established AAV-patients than controls. Saliva microbiota in acute-AAV showed higher within-sample diversity but fewer detectable amplicon-sequence variants and taxa in their core microbiota than controls. Acute-AAV was not associated with increased abundance of periodontal bacteria but species in, e.g., Arthrospira, Staphylococcus, Lactobacillus, and Scardovia. In conclusion, the IgG profiles against oral bacteria differed between pre-AAV, established AAV, and controls, and microbiota profiles between acute AAV and controls. The IgG shift from a pre-symptomatic stage to established disease cooccurred with treatment of immunosuppression and/or antibiotics.

Effect of Locally Delivered Minocycline on the Profile of Subgingival Bacterial Genera in Patients with Periodontitis: A Prospective Pilot Study

This prospective pilot study aimed to evaluate the effect of minocycline-HCl ointment (MO), locally delivered as an adjunct to scaling and root planing (SRP), on subgingival microflora. A total of 59 periodontitis patients received SRP as an initial periodontal therapy. In the selected periodontal pockets with probing depths (PD) of 6−9 mm, the sites that exhibited a positive reaction following a bacterial test using an immunochromatographic device were subsequently treated with MO (SRP + MO group, n = 25). No additional treatment was performed at sites showing a negative reaction (SRP group, n = 34). In addition to subgingival plaque sampling, measurement of clinical parameters including PD, clinical attachment level (CAL), bleeding on probing (BOP), plaque index and gingival index (GI) were performed at baseline and 4 weeks after the initial periodontal therapy. The subgingival microflora were assessed by terminal restriction fragment-length polymorphism analysis. Relative to baseline values, the mean scores for PD-, CAL-, BOP-, and GI-sampled sites were significantly decreased post treatment in both groups (p < 0.01). The intra-comparisons showed a significant decrease in the counts of the genera Eubacterium, Parvimonas, Filifactor, Veillonella, Fusobacterium, Porphyromonas, Prevotella, and unknown species in the SRP + MO group (p < 0.05). Inter-comparisons indicated a significant decrease in the genera Veillonella in the SRP + MO group (p = 0.01). Combination therapy of SRP and local MO induced a change in the subgingival microbial community: particularly, the number of Veillonella spp. was markedly reduced.

Association between periodontitis and chronic kidney disease

Periodontitis and chronic kidney disease are chronic conditions with high community prevalence across the world. Patients with chronic kidney disease have been noted to have a high burden of periodontitis, and several shared risk factors have been associated with the prevalence and severity of both conditions. However, the precise relationship between the two conditions, and the extent to which each may contribute to the development of the other, remains a matter of debate. The goals of the present work were to: (a) provide the most current and relevant literature overview of the association between periodontitis and chronic kidney disease; (b) explore mechanisms underlying this association; and (c) determine if evidence exists for an independent association between these conditions. We also assessed whether improved oral hygiene and periodontal treatment could reduce the risk of developing chronic kidney disease and, if so, what protocols these strategies involve. Finally, we aimed to reveal gaps in our current knowledge to delineate the directions of future research. Although the exact relationship between these two conditions has not yet been defined, we highlight the importance of the interprofessional interaction between dental practitioners and the nephrology team and the importance of oral health assessment in the management of chronic kidney disease.

Clinical effectiveness of adjunctive diode laser on scaling and root planing in the treatment of periodontitis: is there an optimal combination of usage mode and application regimen? A systematic review and meta-analysis

This review aims to evaluate the adjunctive clinical effectiveness of diode laser (DL) to scaling and root planing (SRP) in the treatment of periodontitis, and identify the optimal combination of usage mode and application regimen of DL. Eight electronic databases were searched up to January 2021. Probing pocket depth (PPD), clinical attachment loss (CAL), bleeding on probing (BOP), plaque index (PI), and gingival index (GI) were assessed at short-term (4-6 weeks), 3-month, and 6-month follow-ups. Based on DL usage mode, studies were divided into three groups: inside, outside pocket, and combined modes. As for application regimen, studies in each group were further subdivided into single- and multiple-session subgroups. Thirty randomized controlled trials with 825 participants were included. For inside mode, single-session DL showed significant improvements for PPD (short-term, and 3-month, p < 0.05), CAL (short-term, and 3-month, p < 0.05), PI (3- and 6-month, p < 0.05), and GI (short-term, 3-month, and 6-month, p < 0.05). For outside mode, multiple-session DL showed notable improvements for most clinical outcomes (p < 0.05). The effect of combined mode was still uncertain. Adjunctive DL had additional clinical benefits in the treatment of periodontitis. One session laser treatment is suggested when DL is applied inside pocket in future clinical practice. Meanwhile, more than one session laser treatment presents better outcomes when DL is used outside pocket. PROSPERO: CRD42020156162.

Efficacy and Safety of Modified Yunu-Jian in Patients with Periodontitis: A Meta-Analysis

Background

Modified Yunu-Jian (mYJ), a Chinese medicine (CM) formula, is thought to clear heat and nourish yin. Clinically, it is often used to treat oral inflammation. However, its efficacy remains controversial.

Methods

The study aims to evaluate the efficacy and safety of mYJ for treating patients with periodontitis. We searched electronic databases (PubMed, Cochrane Library, Embase, China National Knowledge Infrastructure, Wanfang database, VIP database, and CBM) from inception to December 2020. Only randomized controlled trials investigating modified Yunu-Jian, with or without other medications, against controlled intervention in the treatment of patients diagnosed with periodontitis were included. Both Review Manager 5.3 and Stata 15.0 software were used to analyze the data. The Cochrane Collaborations risk of bias tool was used to assess the quality of the methods.

Results

Thirteen clinical trials, involving 1179 participants, were included in our investigation. The results showed that the combination of mYJ with western medicine improved the total effective rate compared with western medicine alone (RR = 1.17, 95% CI (1.12, 1.23), P < 0.00001). The sensitivity analysis and Harbord's test (P = 0.255) both showed that the results were statistically robust. Moreover, the periodontal indexes (GI, SBI, PLI, and PD; P < 0.00001) of patients with periodontitis were also significantly improved after receiving the combined therapy. No serious adverse reactions were observed in the experimental groups.

Conclusions

Evidence from the meta-analysis suggested that mYJ appeared to be effective and relatively safe for treating periodontitis. Because of the low quality of the methods used in the included RCTs, further studies with larger sample sizes and well-designed models are required to confirm our findings.

Photodynamic Therapy for Biomodulation and Disinfection in Implant Dentistry: Is It Feasible and Effective?

Dental implants are the most common rehabilitation and restorative treatment used to replace missing teeth. Biofilms adhere to implant surfaces to trigger implant-associated infection and inflammatory response. Clinically, the biofilm induces a local host response with the infiltration of phagocytic immune cells. The pro-inflammatory surroundings set off osteoclastogenesis, which leads to the septic loosening of the implant. The standard of dental care for implant-associated infection relies on a combination of surgery and antimicrobial therapy. Antimicrobial photodynamic therapy is a noninvasive and photochemistry-based approach capable of reducing bacterial load and modulating inflammatory responses. In this review, we explore the photobiomodulation and disinfection outcomes promoted by photodynamic therapy for implant infections, highlighting the quality of evidence on the most up-to-date studies, and discuss the major challenges on the advance of these therapeutic strategies.

Anti-Early Stage of Bacterial Recolonization Effect of Curcuma longa Extract as Photodynamic Adjunctive Treatment

Objective

To evaluate the amount of Fusobacterium nucleatum (F. nucleatum) and Prevotella intermedia (P. intermedia) on subgingival recolonized plaque after mechanical debridement and photodynamic treatment by using blue light-emitting diodes (LEDs) in combination with topical Curcuma longa gel extract.

Methods

A total of 12 subjects with stage III grade B periodontitis were recruited for the study. Maxillary posterior teeth with periodontal pocket >4 mm were selected. These teeth were examined for periodontal clinical data at baseline and at 1, 2, 4, and 6 weeks after treatment. All remaining teeth were treated by scaling and root planing (SRP). Then, the teeth were bilaterally divided using randomized split-mouth design with and without photodynamic adjunctive therapy (PDT). Samples of the subgingival microbiota were obtained in each visit. All samples were analyzed by multicolor TaqMan real-time polymerase chain reaction (PCR) for the presence of target bacteria.

Results

Throughout the six-week follow-up, long-term improvement of probing depth and bleeding on probing was revealed on the PDT group. The number of subgingival F. nucleatum and P. intermedia also significantly reduced, compared to the baseline. There was a statistically significant recolonization in F. nucleatum and P. intermedia number after 2 and 4 weeks of conventional SRP, respectively. Our quantitative PCR method showed no significant recolonization of those subgingival bacteria on PDT sites throughout the 6-week study duration.

Conclusion

The results showed that adjunctive photodynamic treatment by using blue LEDs in combination with topical Curcuma longa gel extract was effective to alter the recolonization patterns of F. nucleatum and P. intermedia after conventional debridement.

Adjunctive systemic antimicrobials in the treatment of chronic periodontitis: A systematic review and network meta-analysis

The aim of this systematic review and network meta-analysis was to assess the efficacy of antimicrobials adjunctive to scaling and root planing (SRP) in the treatment of chronic periodontitis. The study was conducted according to the PRISMA statement. The protocol (CRD42020178621) was registered on the International Prospective Register of Systematic Reviews (PROSPERO). The MEDLINE, EMBASE, and CENTRAL databases were searched up to March 2020; furthermore, a manual search of relevant periodontal journals was conducted. Mean differences (MD) and standard deviations were calculated for clinical attachment level (CAL) gain and probing depth (PD) reduction at 6 and 12 months. A network meta-analysis was performed to assess direct and indirect comparisons and to establish a ranking of treatments. A total of 21 randomized clinical trials (RCTs) were included in the systematic review. Network meta-analysis showed that SRP + amoxicillin (AMX) + metronidazole (MTZ), as compared to SRP, reached the highest PD reduction at 6 [MD = 0.47; 95% CI (0.3; 0.64)] and 12 months [MD = 0.51; 95% CI (0.25; 0.78)], and CAL gain at 6 [MD = 0.54; 95% CI (0.27; 0.8)] and 12 months [MD = 0.37; 95% CI (0.05; 0.69)]. Network meta-analysis indicated that AMX + MTZ adjunctive to SRP provided the best improvement in clinical parameters, followed by SRP + MTZ.

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.

Adjunctive Antiseptic Irrigation of Periodontal Pockets: Effects on Microbial and Cytokine Profiles

To evaluate the effect of adjunctive antiseptic irrigation of periodontal pockets on microbial and cytokine profiles. Fifty-nine patients with severe periodontitis were allocated to one of three groups for scaling and root planing facilitated with different adjunctive antiseptics: 1% polyhexamethyleneguanidine phosphate (PHMG-P) (n = 19), 0.2% chlorhexidine (CHX) (n = 21) or distilled water (n = 19). Gingival crevicular fluid and subgingival bacterial samples were collected at baseline, and at 2 weeks, and 1 and 4 months. The levels of interleukin (IL)-1β, IL-8, IL-10, and IL-17A, matrix metalloproteinase (MMP)-8, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Fusobacterium nucleatum,Aggregatibacter actinomycetemcomitans, and Prevotella intermedia were determined. There were no intergroup differences in cytokine concentrations and bacterial counts at any follow-up, however, varying patterns were observed. In the PHMG-P and water groups IL-1β expression peaked at 2 weeks and then gradually declined. In all three groups, the dynamics of MMP-8 concentration were non-linear, increasing by 2 weeks and then declining to below baseline (p > 0.05). P. gingivalis and T. forsythia declined within the first month and increased thereafter, not regaining the baseline level. Adjunctive antiseptic treatment was associated with changes in biomarkers and bacterial counts in the course of the study. The effects of adjunctive antiseptic irrigation were limited in the applied protocol.

Impact of Local Drug Delivery of Minocycline on the Subgingival Microbiota during Supportive Periodontal Therapy: A Randomized Controlled Pilot Study

The aim of this study was to examine the effect of adjunct local minocycline administration on the microbiological parameters of subgingival plaque samples in the residual periodontal pockets. Ten chronic periodontitis patients under a supportive periodontal therapy regimen were recruited. After subgingival debridement, either 2% minocycline gel, Periocline™, (Test Group) or a placebo (Control Group) was administered to the selected sites once a week for three weeks. Subgingival plaque was collected at baseline, and at four weeks and eight weeks. The microbiological composition was analyzed by 16S ribosomal RNA sequencing. In the Test Group, α-diversity (evenness) decreased compared to the baseline (p = 0.005) and was lower compared to the control group at four weeks (p = 0.003). The microbial community composition between the two groups was significantly different at four weeks (p = 0.029). These changes were attributable to a decrease in the bacteria associated with periodontitis and an increase in the bacteria associated with periodontal health. Additionally, the improvement in bleeding on probing continued at eight weeks; however, there were little microbial effects of 2% minocycline gel observed at eight weeks. The control group demonstrated no change throughout the eight-week experimental period. Thus, local minocycline administration can change the subgingival microbial community of residual periodontal pockets.

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.

Influence of adjunctive azithromycin on microbiological and clinical outcomes in periodontitis patients: 6-month results of randomized controlled clinical trial

BACKGROUND

Our aim was to determine if azithromycin therapy, as an adjunct to scaling and root planing (SRP), decreases the number of pathobiontic subgingival plaque species and sites demonstrating pocket depth (PD) ≥ 5 mm and bleeding on probing (BOP) 6 months post-treatment.

METHODS

In a double-blind randomized parallel-arm placebo-controlled trial, 40 patients received nonsurgical periodontal treatment in two sessions within 7 days. Patients then received systemic antibiotic therapy (n = 20, azithromycin 500 mg/day for 3 days) or placebo (n = 20). Pooled microbiologic samples were taken before and 6 months after therapy and analysed by established culture methods. The primary outcome variable was the number of sites with PD ≥ 5 mm and BOP at the 6-month re-evaluation. Using multivariate multilevel logistic regression, the effects of gender, age, antibiotic therapy, presence of P. gingivalis or A. actinomycetemcomitans, smoking, tooth being a molar and interdental location were evaluated.

RESULTS

The number of sites with PD ≥ 5 mm and BOP after 6 months was similar in the test (Me = 4, IQR = 0-11) and control (Me = 5, IQR = 1-22) group. Adjunctive azithromycin treatment, compared to SRP alone, resulted in more frequent eradication of A. actinomycetemcomitans (p = 0.013) and C. rectus (p = 0.029), decreased proportion (p = 0.006) and total counts (p = 0.003) of P. gingivalis, and decreased proportion of C. rectus (p = 0.012). Both groups showed substantial but equivalent improvements in periodontal parameters, with no intergroups differences at initially shallow or deep sites. The logistic regression showed a lower odds ratio for healing of diseased sites on molars (OR = 0.51; p <  0,001).

CONCLUSION

Despite significant changes in numbers of A. actinomycetemcomitans, P. gingivalis and C. rectus, patients with periodontitis do not benefit from adjunctive systemic azithromycin in terms of number of persisting sites with PD ≥ 5 mm and BOP.

TRIAL REGISTRATION

EUDRA-CT: 2015-004306-42; https://www.clinicaltrialsregister.eu/ctr-search/trial/2015-004306-42/SI , registered 17. 12. 2015.

Brazilian Red Propolis Is as Effective as Amoxicillin in Controlling Red-Complex of Multispecies Subgingival Mature Biofilm In Vitro

This study investigated the effects of Brazilian Red Propolis (BRP) extract on seven-day-old multispecies subgingival biofilms. Mixed biofilm cultures containing 31 species associated with periodontal health or disease were grown for six days on a Calgary device. Then, mature biofilms were treated for 24 h with BRP extract at different concentrations (200-1600 µg/mL), amoxicillin (AMOXI) at 54 µg/mL (positive control) or vehicle (negative control). Biofilm metabolic activity was determined by colorimetry, and bacterial counts/proportions were determined by DNA-DNA hybridization. Data were analyzed by Kruskal-Wallis and Dunn's tests. Treatment with BRP at 1600, 800 and 400 μg/mL reduced biofilm metabolic activity by 56%, 56% and 57%, respectively, as compared to 65% reduction obtained with AMOXI. Mean total cell counts were significantly reduced in all test groups (~50-55%). Lower proportions of red, green and yellow complex species were observed upon treatment with BRP (400 µg/mL) and AMOXI, but only AMOXI reduced the proportions of Actinomyces species. In conclusion, BRP extract was as effective as AMOXI in killing seven-day-old multispecies biofilm pathogens and did not affect the levels of the host-compatible Actinomyces species. These data suggest that BRP may be an alternative to AMOXI as an adjunct in periodontal therapy. In vivo studies are needed to validate these results.

Antiseptics as adjuncts to scaling and root planing in the treatment of periodontitis: a systematic literature review

BACKGROUND

Periodontitis is microbially-associated, host-mediated inflammatory condition that results in loss of periodontal attachment. The goals of periodontal therapy include arresting the disease progression, establishing healthy, stable, maintainable periodontal conditions. A fundamental strategy of treating periodontitis is scaling and root planning (SRP), however its efficacy may be restricted in areas inaccessible for mechanical instrumentation. As periodontitis is infectious in nature, it might be helpful to use additional antimicrobial adjuncts, in order to eliminate or inactivate pathogenic microflora. The aim of this study is to evaluate the current evidence regarding the potential clinical benefits of using additional antiseptics for SRP in nonsurgical periodontal therapy.

METHODS

An electronic literature search was conducted in the MEDLINE (Ovid) and Cohrane Central Register of Controlled Trials (CENTRAL) databases for articles published between January 1, 2000 and September 22, 2019. Randomized controlled clinical trials in English that compare the effectiveness of one or more antiseptic agents as adjuncts to SRP with a follow-up of ≥6 months were included. A meta-analysis using the random-effects model was performed on the selected qualifying articles.

RESULTS

The search resulted in 12 articles that met the inclusion criteria. Based on the vehicle employed to deliver the antiseptic agent, studies were divided into adjunctive sustained-release antiseptics (gels, chips and varnish) and adjunctive irrigation with antiseptics. The meta-analysis demonstrated significant improvements in probing depth (PD) reduction (p = 0.001), clinical attachment level (CAL) gain (p = 0.001), and bleeding on probing (BOP) values (p = 0.001) following the adjunctive subgingival application of sustained-release antiseptics. Additional subgingival irrigation with antiseptics failed to show significant improvements in PD (p = 0.321), CAL (p = 0.7568), or BOP values (p = 0.3549) over SRP alone.

CONCLUSIONS

Adjunctive subgingivally delivered antiseptics with a sustained-release delivery have significant clinical benefits compared to SRP alone.

Characterization of the subgingival microbiota in the peritoneal dialysis patients with periodontitis

BACKGROUND AND OBJECTIVE

Periodontitis is an oral chronic inflammatory disease caused by dental plaque. It is comorbid with numerous systemic diseases and associated with several predisposing factors, such as chronic kidney disease (CKD). Peritoneal dialysis is one of the ultimate treatments for patients with severe CKD. However, peritoneal dialysis patients with periodontitis often will be accompanied with more poor oral hygiene and periodontal clinical indexes. This study aimed to compare the microbial flora of periodontitis patients with or without peritoneal dialysis.

METHODS

Sixteen peritoneal dialysis patients with periodontitis (P group) and 16 patients with periodontitis only (C group) were selected. Subgingival plaque samples of them were processed for bioinformatics analysis by 16S rDNA gene sequencing.

RESULTS

The diversity indices and species richness in the P group were insignificantly higher than that in the C group (P > 0.05). The two groups exhibited different microbial community structure. At Genus level, Prevotellaceae, Selenomonas, Aggregatibacter, Anaeroglobus, TM7_[G-5], and Centipeda were significantly enriched in the P group than those in the C group.

CONCLUSIONS

This study demonstrated that specific microbes enriched in the subgingival flora of peritoneal dialysis patients with periodontitis.

Saliva as a diagnostic tool for dental caries, periodontal disease and cancer: is there a need for more biomarkers?

Introduction: A biomarker is a biological indicator of normal or pathogenic processes. Identification of biomarkers is useful for the prevention, diagnosis and prognosis of diseases as well as for monitoring the progression of pathological disorders. Several types of molecules present in biological fluids can act as biomarkers such as DNA, coding and non-coding RNA, lipids, metabolites, proteins and even microbes. In this context, saliva emerges as a useful diagnostic tool for the detection of biomarkers involved with oral and systemic diseases, since it reflects the pathophysiological conditions of the organism and allows early, rapid, practical and noninvasive detection of biomarkers.Areas covered: This review discusses the properties of saliva as a diagnostic tool and addresses the main identified biomarkers related to dental caries, periodontal disease, head and neck cancer and other types of cancer of considerable incidence among the world population.Expert commentary: Despite extensive efforts which have been directed toward the identification of one or a combination of biomarkers with good predictive values for the early detection of dental caries, periodontal disease and cancer, these biomarkers still need validation before chairside point-of-care devices can be widely used in the clinic.

Effects of timing of adjunctive systemic antibiotics on the clinical outcome of periodontal therapy: A systematic review

Background

Many systematic reviews and meta-analysis have indicated beneficial effects of adjunctive systemic antibiotics in periodontal therapy in specific situations. However, some essential issues such as the ideal time of their administration during periodontal therapy remain unanswered. This systematic review aimed to determine at which phase of periodontal treatment would adjunctive systemic antibiotics lead to the best clinical outcomes, during the active phase or in the reevaluation phase.

Material and Methods

Searches in the databases Medline, Scopus and Cochrane Library were conducted. The randomized clinical trials and retrospective cohort studies comparing the clinical benefits of adjunctive systemic antibiotic administration in the active phase of periodontal treatment versus their administration in the reevaluation phase were included. The primary outcomes assessed were differences in clinical changes in periodontal pocket depth and clinical attachment loss at all post-treatment phases.

Results

Of the 6209 records identified, two randomized clinical trials and two retrospective cohort studies were eligible according to inclusion criteria. Two studies suggested there were greater clinical benefits when systemic antibiotics were prescribed during the active phase of periodontal therapy than in the reevaluation phase while two other studies showed no significant difference in clinical outcomes at 6 months between these two different timing of administration.

Conclusions

The evidence available and evaluated in this systematic review is of heterogeneous quality and limited by the restricted number of studies and their dissimilarities in their study design and outcome reporting. Despite insufficient evidence to determine the ideal time to the adjunctive systemic antibiotic administration in the periodontal therapy, it seems that prescription of systemic antibiotic at the active phase of periodontal therapy leads to better clinical outcomes.

Key words:Active phase; periodontal therapy, periodontitis, reevaluation, systemic antibiotics, timing.

Epstein-Barr virus-infected plasma cells in periodontitis lesions

Growing evidence supports that the Epstein-Barr virus (EBV) is a putative periodontal pathogen, but little is known regarding EBV behavior in periodontitis. Here, EBV infection was monitored in saliva and periodontal pocket (PP), at baseline and 3 months after periodontal non-surgical therapy (p-NST) in 20 patients diagnosed with periodontitis. After the treatment, the patients with the improved periodontal condition (good responders) showed a significant decrease in salivary EBV load. In contrast, in poor responders, EBV load was slightly increased. Moreover, after the therapy, most patients showed clear signs of EBV infection in a deep PP (≥5 mm) selected as a study site. To investigate how EBV can persist in a PP, we further investigate cellular sites of viral replication in PP. We identified large amounts of infiltrated EBV-infected cells, mostly overlapping with CD138⁺ plasma cells (PC). EBV-infected PCs formed high-density clusters within the infiltrate and along the periodontal epithelium which were commonly associated with CD3⁺ T-cells and CD20⁺ B-cells to evoke diffuse ectopic lymphoid-like structures. Taking together, this study provides new insights to support a model where the periodontal condition may play a major role in oral EBV shedding. Since PC harbors the late productive phases of EBV replication, the periodontal condition may favor B-cell differentiation with possible amplification of periodontal EBV infection and viral spreading. PCs have long been recognized as pathogenic markers in inflammatory lesions. Our finding sheds new light on the role of EBV infection and PC in periodontitis.

Development of Oral Care Chip, a novel device for quantitative detection of the oral microbiota associated with periodontal disease

Periodontal disease, the most prevalent infectious disease in the world, is caused by biofilms formed in periodontal pockets. No specific bacterial species that can cause periodontitis alone has been found in any study to date. Several periodontopathic bacteria are associated with the progress of periodontal disease. Consequently, it is hypothesized that dysbiosis of subgingival microbiota may be a cause of periodontal disease. This study aimed to investigate the relationship between the subgingival microbiota and the clinical status of periodontal pockets in a quantitative and clinically applicable way with the newly developed Oral Care Chip. The Oral Care Chip is a DNA microarray tool with improved quantitative performance, that can be used in combination with competitive PCR to quantitatively detect 17 species of subgingival bacteria. Cluster analysis based on the similarity of each bacterial quantity was performed on 204 subgingival plaque samples collected from periodontitis patients and healthy volunteers. A significant difference in the number of total bacteria, Treponema denticola, Campylobacter rectus, Fusobacterium nucleatum, and Streptococcus intermedia bacteria in any combination of the three clusters indicated that these bacteria gradually increased in number from the stage before the pocket depth deepened. Conversely, Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia, and Streptococcus constellatus, which had significant differences only in limited clusters, were thought to increase in number as the pocket depth deepened, after periodontal pocket formation. Furthermore, in clusters where healthy or mild periodontal disease sites were classified, there was no statistically significant difference in pocket depth, but the number of bacteria gradually increased from the stage before the pocket depth increased. This means that quantitative changes in these bacteria can be a predictor of the progress of periodontal tissue destruction, and this novel microbiological test using the Oral Care Chip could be effective at detecting dysbiosis.

OCT-Based Periodontal Inspection Framework

Periodontal diagnosis requires discovery of the relations among teeth, gingiva (i.e., gums), and alveolar bones, but alveolar bones are inside gingiva and not visible for inspection. Traditional probe examination causes pain, and X-ray based examination is not suited for frequent inspection. This work develops an automatic non-invasive periodontal inspection framework based on gum penetrative Optical Coherence Tomography (OCT), which can be frequently applied without high radiation. We sum up interference responses of all penetration depths for all shooting directions respectively to form the shooting amplitude projection. Because the reaching interference strength decays exponentially with tissues' penetration depth, this projection mainly reveals the responses of the top most gingiva or teeth. Since gingiva and teeth have different air-tissue responses, the gumline, revealing itself as an obvious boundary between teeth and gingiva, is the basis line for periodontal inspection. Our system can also automatically identify regions of gingiva, teeth, and alveolar bones from slices of the cross-sectional volume. Although deep networks can successfully and possibly segment noisy maps, reducing the number of manually labeled maps for training is critical for our framework. In order to enhance the effectiveness and efficiency of training and classification, we adjust Snake segmentation to consider neighboring slices in order to locate those regions possibly containing gingiva-teeth and gingiva-alveolar boundaries. Additionally, we also adapt a truncated direct logarithm based on the Snake-segmented region for intensity quantization to emphasize these boundaries for easier identification. Later, the alveolar-gingiva boundary point directly under the gumline is the desired alveolar sample, and we can measure the distance between the gumline and alveolar line for visualization and direct periodontal inspection. At the end, we experimentally verify our choice in intensity quantization and boundary identification against several other algorithms while applying the framework to locate gumline and alveolar line in vivo data successfully.

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.

Treponema denticola transcriptional profiles in serum-restricted conditions

Treponema denticola is a major pathogen in periodontal disease and is frequently isolated from the lesions of patients with chronic periodontitis. Treponema denticola utilizes serum components as nutrient sources so as to colonize and proliferate in the gingival crevice. However, the mechanisms of serum utilization remain unclear. Therefore, the aim of the present study was to identify T. denticola serum utilization genes. Precultured T. denticola cells were suspended in a tryptone-yeast extract-gelatin-volatile fatty acids medium containing 0, 1% and 10% serum, respectively, and incubated anaerobically for 17 h. Total RNA was isolated, and T. denticola gene expression was compared by microarray and reverse transcription-polymerase chain reaction. In serum-depleted conditions, the expression levels of a potential hydroxylamine reductase, several ABC transporters, and phosphoenolpyruvate synthase were increased, while those of genes encoding methyl-accepting chemotaxis proteins and a transcriptional regulator were decreased. These results suggest that T. denticola may uptake serum components mainly through the action of ABC transporters. In particular, the decrease in the dmcA expression level with decreasing serum concentration suggests its involvement in chemotaxis toward serum-rich environments.

Method for absolute quantification of microbial communities by using both microarrays and competitive PCR

Methods for the robust quantification of bacterial communities are still under development. In this context, the present study aimed to evaluate a method combining competitive PCR (cPCR) and microarray assays for the determination of absolute content of total bacteria and individual bacterial species in samples. For this, a competitor DNA for cPCR and microarrays containing three types of DNA probes was prepared. A calibration curve was generated with genomic DNA samples as standards, which was then utilized for cPCR-based determination of the total number (in moles) of 16S rRNA genes in other bacterial samples. Moreover, scatter plots of species-specific probes versus total bacteria probe for each genomic DNA of known concentration was fit to the regression model, and the obtained slope value was defined as the hybridization affinity ratio. The cPCR assay was performed for both a commercially available mixed genomic DNA sample and human oral bacterial DNA samples, and the total number of moles of 16S rRNA genes was determined. These values were distributed among each species on the basis of the signal intensities of species-specific probes and the hybridization affinity ratio. The total number of bacterial genomes and those of individual species were determined by dividing the copy number of 16S rRNA genes per genome. The obtained results were confirmed by quantitative real-time PCR (qPCR). For values of >1 × 10² copies determined by qPCR, the ratio of the values measured by DNA chips to by qPCR was 1.53-fold on average and <2.6-fold for all data. These results show that the combined method of cPCR and microarray is useful to quantify the absolute numbers of several types of bacteria in a sample at one time.

Effects of a self-ligating appliance for orthodontic treatment of severe adult periodontitis

This study was conducted to investigate the short-term effects of a self-ligating appliance for orthodontic treatment of severe adult periodontitis. Thirty patients diagnosed as severe periodontitis were recruited at Nanjing Stomatological Hospital, P. R.China, between January 2012 and January 2016. General clinical and demographic data were collected from the patients, all of whom were treated with a self-ligating appliance. Probing pocket depth (PPD), clinical attachment level (CAL), bleeding on probing (BOP) and plaque index (PI) were measured before appliance placement, and at 1 and 3 months after appliance placement, respectively. Results showed the rate of tooth loss, mean PPD, mean CAL and the BOP ratio were more favorable in healthy subjects than in the patients. Smokers accounted for a significantly higher proportion of the patients in comparison with the healthy subjects. Clinical outcomes revealed that both the mean PPD and mean CAL were significantly decreased compared with the baseline (P < 0.05). Furthermore, the percentage of BOP, PI and bone mineral density were also significantly decreased at 1 month after treatment (P < 0.05). The volume of gingival crevicular fluid, as well as the levels of alkaline phosphatase, aspartate aminotransferase and glutathione peroxidase, were significantly increased in the first month after treatment, being decreased at 2 months, and finally returning to normal in the third month. In summary, orthodontic treatment using a self-ligating appliance can apparently improve the periodontal condition of patients with severe adult periodontitis.

Non-surgical therapeutic outcomes of peri-implantitis: 12-month results

OBJECTIVES

To assess the clinical and radiographic outcomes of implants treated by means of non-surgical debridement with systemic antibiotic therapy.

MATERIALS AND METHODS

A prospective case series study evaluating the 12-month clinical and radiographic outcomes of peri-implantitis lesions treated with ultrasonic scaler debridement, a glycine air abrasive, and metronidazole followed by supportive maintenance. Clinical and radiographic variables and success criteria were defined a priori.

RESULTS

Overall, 21 patients were included. One implant failed during the study period (implant survival rate 95.24%). Substantial changes occurred at 12 months in all the clinical and radiographic variables, reaching strong statistical significance in the majority of them. According to the success criteria applied, 40.90% of the peri-implantitis were arrested and resolved, while 59.1% presented with at least one probed site with bleeding on probing (BoP). Moreover, 95.45% exhibited peri-implant pocket depth (PPD) < 5 mm at the end of the study. None of the implants presented with progressive bone loss.

CONCLUSION

Non-surgical therapy of peri-implantitis is effective to arrest progressive bone loss, reduce PPD and suppuration, and achieve radiographic bone fill in the majority of cases. Nevertheless, it failed to be completely efficacious in the achievement of successful therapeutic outcomes as BoP remained frequently present.

CLINICAL RELEVANCE

Non-surgical therapy achieved significant clinical and radiological improvements.

Metronidazole: an update on metabolism, structure-cytotoxicity and resistance mechanisms

Metronidazole, a nitroimidazole, remains a front-line choice for treatment of infections related to inflammatory disorders of the gastrointestinal tract including colitis linked to Clostridium difficile. Despite >60 years of research, the metabolism of metronidazole and associated cytotoxicity is not definitively characterized. Nitroimidazoles are prodrugs that are reductively activated (the nitro group is reduced) under low oxygen tension, leading to imidazole fragmentation and cytotoxicity. It remains unclear if nitroimidazole reduction (activation) contributes to the cytotoxicity profile, or whether subsequent fragmentation of the imidazole ring and formed metabolites alone mediate cytotoxicity. A molecular mechanism underpinning high level (>256 mg/L) bacterial resistance to metronidazole also remains elusive. Considering the widespread use of metronidazole and other nitroimidazoles, this review was undertaken to emphasize the structure-cytotoxicity profile of the numerous metabolites of metronidazole in human and murine models and to examine conflicting reports regarding metabolite-DNA interactions. An alternative hypothesis, that DNA synthesis and repair of existing DNA is indirectly inhibited by metronidazole is proposed. Prokaryotic metabolism of metronidazole is detailed to discuss new resistance mechanisms. Additionally, the review contextualizes the history and current use of metronidazole, rates of metronidazole resistance including metronidazole MDR as well as the biosynthesis of azomycin, the natural precursor of metronidazole. Changes in the gastrointestinal microbiome and the host after metronidazole administration are also reviewed. Finally, novel nitroimidazoles and new antibiotic strategies are discussed.

Exploring a temporal relationship between biofilm microbiota and inflammatory mediators during resolution of naturally occurring gingivitis

BACKGROUND

This study uses multiple, contemporary methodologies to expand our knowledge of the temporal relationship between host-microbial interactions and clinical signs of gingivitis.

METHODS

Subgingival plaque and crevicular fluid samples were collected from 31 systemically healthy adults with naturally occurring plaque-induced gingivitis. Professional prophylaxis was administered and participants were followed over 7 weeks. Microbial characterization was performed using a bead-based hybridization assay and cytokine analysis using bead-based flow cytometry.

RESULTS

The provision of sequential interventions, oral hygiene instruction, and subsequent professional prophylaxis brought about significant reduction of plaque and resolution of gingivitis at all post baseline time points (P < 0.0001). Candidate cytokines that increased significantly (95% level) were interleukin (IL)-1β, matrix metalloproteinases (MMP)-1, MMP-3, MMP-8, MMP-9, from baseline to week 2; regulated on activation, normal T cell expressed and secreted (RANTES) at week 4 and week 8; macrophage inflammatory protein (MIP)-1α and MIP-1β at week 8. Resolution of inflammation was accompanied by a shift in the microbiological flora toward those species associated with health.

CONCLUSIONS

This study provides further evidence of the dynamic relationships that exist between the overt clinical signs, the microbial biofilm, and the host response in gingivitis and upon resolution following clinical interventions. Understanding the interactions between the host immune system and subgingival microbial communities during the resolution of established gingivitis continues to evolve as additional knowledge is achieved through using new analytical technologies. The present study confirms a critical effect of oral hygiene measures on restoration of microbial eubiosis in subgingival communities, confirming the important role for home care and professional intervention in maintaining oral health.

Preliminary Phytochemical Analysis of Berberis goudotii Triana & Planch. ex Wedd. (Berberidaceae) with Anticariogenic and Antiperiodontal Activities

Berberis goudotii is an endemic Colombian plant found in the paramo ecosystem. It has been used in food preparation and as a medicinal plant for diverse treatments. Additionally, it is used as a mouthwash to strengthen the gums and combat throat irritations and periodontitis. The present research evaluated Berberis goudotii aerial parts extract and fractions antimicrobial activities. Ultrasonic-assisted extraction was used to attain total ethanol-water extract. Solid-liquid fractionation was used to obtain hexane fraction. The residue was dispersed in water and liquid-liquid fractionation was carried-out to acquire dichloromethane, butanol and water fractions. Preliminary phytochemical analysis was performed on total extract and phenol, polyphenol, flavonoid, and proanthocyanidin, while tannin content was quantified. Antimicrobial activity assessment was performed by agar diffusion method using disks and wells employing Ceftazidime as a positive control against Streptococcus mutans, Streptococcus sobrinus, Lactobacillus acidophilus, Lactobacillus casei, Porphyromonas gingivalis, Prevotella intermedia and Fusobacterium nucleatum. Antimicrobial activity was determined as relative percentage inhibition (RPI), minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Phenols (92.5 ± 7.7 mg GA/10 g), polyphenols (87.7 ± 8.1 mg PG/10 g) and tannins (44.1 ± 4.3 mg PG/10 g) were among the highest secondary metabolites observed. Total extract presented an MBC of 1.0 µg/µL against cariogenic bacteria (Streptococcus mutans and Streptococcus sobrinus) and 0.12 µg/µL against bacteria associated with periodontal disease (Porphyromonas gingivalis, Prevotella intermedia and Fusobacterium nucleatum). Butanol and hexane fractions showed antiperiodontal activity with MBC of 0.12 and 1.0 µg/µL, respectively. In conclusion, Berberis goudotii total extract demonstrated antimicrobial activity against cariogenic and periodontal microorganisms, on the other hand, hexane and butanol fractions displayed antiperiodontal activity.

Microbiological Response to Periodontal Therapy: A Retrospective Study

BACKGROUND

Periodontitis is a multifactorial infection caused by a complex of pathogenic bacterial species that induce the destruction of periodontal structures.

OBJECTIVE

The aim of this study is to evaluate the presence and bacterial load of six periodontal pathogens bacteria, measured at initial visit and after osseous surgery in patients affected by chronic periodontitis and treated between 2005 and 2007.

METHODS

This cohort study was carried out on a sample of 38 consecutive patients affected by severe chronic periodontitis, diagnosed at baseline on the basis of probing depths equal to 6.68 ± 1.47 mm. On each subject, a microbiological test was performed before periodontal initial therapy and after osseous surgery (one year later). Five compromised teeth were chosen for each patient (the same teeth, before and after surgery), for a total of 190 teeth. Real-time PCR based analysis computed total bacterial load of the samples and quantified six periodontal pathogens: Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Fusobacterium nucleatum and Prevotella intermedia. Data collection was made consulting medical charts.

RESULTS

Pocket probing depth reduction after surgery was 4.50 ± 1.54 mm (p=0.0001). The mean number of sites with bleeding at baseline was 2.08 ± 1.17 and 0.58 ± 1.00 after surgery (p=0.001). The mean number of sites with suppuration at baseline was 0.26 ± 0.86 and 0 after surgery (p=0.02). Cell count of each pathogen and total cell count were significantly higher at baseline than after surgery. Almost all bacteria presented a mean percentage reduction equal to that of the total count, except for Aa and Pi, which seemed to show a greater resistance. The difference of bacterial load, both before and after surgery, between smokers and non-smokers was not statistically significant (p<0.05). A statistically significant correlation was detected between pocket probing depth variation and bleeding on probing variation before and after the surgery, controlling for age (r=0.6, p=0.001). No significant correlations were observed between pocket probing depth and bacterial loads, except for Pg (r=0.5, p=0.001), Tf (r=0.6, p=0.001) and Td (r=0.4, p=0.02).

CONCLUSIONS

Reduction of presence and bacterial load of the examined periodontal pathogens bacteria after osseous surgery, along with periodontal pocket reduction, appeared to be essential to achieve and maintain periodontal stability over years.

Response of epithelial cells infected by Treponema denticola

OBJECTIVE

In the gingival crevice, the interaction between epithelial cells and periodontopathic bacteria is important for the development of periodontitis. Treponema denticola is a major pathogen of chronic periodontitis and possesses several virulence factors, such as major surface protein (Msp) and prolyl-phenylalanine-specific protease (dentilisin). Here, we investigated the behaviours of epithelial cells infected with T. denticola by measuring the expression of interleukin (IL)-1β, IL-6, β defensin 2 (BD-2) and heat-shock protein 70 (HSP70).

METHODS

Epithelial cells were infected with T. denticola wild-type strain, Msp-deficient mutant or dentilisin-deficient mutant, and the expression levels of the above targets were analysed by polymerase chain reaction.

RESULTS

Infection with T. denticola wild-type strain and mutants induced the production of IL-6 and HSP70. The level of BD-2 induced by T. denticola wild-type strain at 24 hr was significantly higher than that of the dentilisin-deficient mutant. The level of IL-1β mRNA in the wild-type strain and dentilisin-deficient mutant was slightly lower than that in the uninfected control.

CONCLUSION

These results suggest that the levels of BD-2 were affected by Msp and dentilisin. This effect may contribute to the disruption of the response of epithelial cells to eradicate T. denticola.

Characterization of a novel potential peptide import system in Treponema denticola

Treponema denticola is a major etiologic agent of chronic periodontitis. On the outer sheath of T. denticola, several proteins, such as the major outer sheath protein and dentilisin were detected, and among them, a 95 kDa protein which has not yet been characterized. The aim of this study was to characterize the function of this 95 kDa protein containing gene cluster. A gene encoding this 95 kDa protein (TDE_1072) of T. denticola was inactivated by homologous recombination. We compared growth curves between the TDE_1072 mutant and wild-type strains as well as differences in gene expression by DNA microarray analysis. Differential expression of genes identified by microarray analysis was confirmed by quantitative reverse transcription-polymerase chain reaction. The proteins encoded by TDE_1072, TDE_1073, TDE_1074, TDE_1075, and TDE_1076 shared respective similarities to the substrate-binding domain (DppA) of an ABC-type dipeptide/oligopeptide/nickel transport system, and to the permease components (DppB and DppC) and ATPase components (DppD and DppF) of an ABC-type dipeptide/oligopeptide/nickel transport system. Inactivation of dppA attenuated the growth of T. denticola and dppA-dppF were co-transcribed. In contrast, expression of oppB-oppF was up-regulated in the mutant. Our findings indicate that TDE_1072 may be a potential periplasmic solute binding protein encoded by dppA that is involved in the organization of a peptide uptake system with dppB-dppF.

Prevention of Periodontitis by the Addition of a Bactericidal Particulate Glass/Glass-Ceramic to a Dental Resin: A Pilot Study in Dogs

The aim of the study is to evaluate, in a ligature-induced periodontitis model, the efficacy of a commercially available dental resin containing different antimicrobial glass/glass-ceramic additions (0–26 wt.%). It has been proved that a 26 wt.% glass addition to a conventional dental resin matrix does not alter neither its workability nor its adhesion to the surface of teeth; however, it does confer notable antimicrobial properties when tested in vitro. Moreover, in vivo tests in Beagle dogs demonstrated the prevention of bone loss in ligature-induced plaque accumulation around teeth. Particularly, the glass-ceramic filler resin composite has shown excellent antimicrobial control since it displays the same bone loss as that of the negative control. The results obtained in the present investigation have shown that a conventional dental resin containing a fraction of glass/glass-ceramic (≥26 wt.%) can prevent periodontitis, which is considered to be a most serious dental disease.