Classic vs. Novel Antibacterial Approaches for Eradicating Dental Biofilm as Adjunct to Periodontal Debridement: An Evidence-Based Overview

Periodontitis is a multifactorial chronic inflammatory disease that affects tooth-supporting soft/hard tissues of the dentition. The dental plaque biofilm is considered as a primary etiological factor in susceptible patients; however, other factors contribute to progression, such as diabetes and smoking. Current management utilizes mechanical biofilm removal as the gold standard of treatment. Antibacterial agents might be indicated in certain conditions as an adjunct to this mechanical approach. However, in view of the growing concern about bacterial resistance, alternative approaches have been investigated. Currently, a range of antimicrobial agents and protocols have been used in clinical management, but these remain largely non-validated. This review aimed to evaluate the efficacy of adjunctive antibiotic use in periodontal management and to compare them to recently suggested alternatives. Evidence from in vitro, observational and clinical trial studies suggests efficacy in the use of adjunctive antimicrobials in patients with grade C periodontitis of young age or where the associated risk factors are inconsistent with the amount of bone loss present. Meanwhile, alternative approaches such as photodynamic therapy, bacteriophage therapy and probiotics showed limited supportive evidence, and more studies are warranted to validate their efficiency.

Pros and Cons of CAD/CAM Technology for Infection Prevention in Dental Settings during COVID-19 Outbreak

The purpose of this commentary is to update the evidence reported in our previous review on the advantages and limitations of computer-aided design/computer-aided manufacturing technology in the promotion of dental business, as well as to guarantee patient and occupational safety. The COVID-19 pandemic led to an unprecedented focus on infection prevention; however, waves of COVID-19 follow one another, asymptomatic cases are nearly impossible to identify by triage in a dental setting, and the effectiveness of long-lasting immune protection through vaccination remains largely unknown. Different national laws and international guidelines (mainly USA-CDC, ECDC) have often brought about dissimilar awareness and operational choices, and in general, there has been very limited attention to this technology. Here, we discuss its advantages and limitations in light of: (a) presence of SARS-CoV-2 in the oral cavity, saliva, and dental biofilm and activation of dormant microbial infections; (b) the prevention of SARS-CoV-2 transmission by aerosol and fomite contamination; (c) the detection of various oral manifestations of COVID-19; (d) specific information for the reprocessing of the scanner tip and the ward from the manufacturers.

Fluoride formed on enamel by fluoride varnish or gel application: A randomized controlled clinical trial

Although fluoride varnish (FV) and acidulated phosphate fluoride gel (APF-gel) are considered clinically effective to reduce caries, in vitro studies have shown that FV reacts slowly with enamel because most NaF present in the formulation is not solubilized in the FV. Therefore, we conducted a clinical study to evaluate if the time that FV remains on dental surfaces could overcome its slower chemical reactivity when compared with APF-gel. Sixty-eight volunteers were randomly allocated into four groups: Negative control (Control, no treatment), APF -gel application (1.23% F applied for 4 min), and FV application (Duraphat®, 2.26 % F) for 4 h (FV-4h) or 24 h (FV-24h). To evaluate fluoride formed and retained on enamel, acid biopsies were made on the buccal surfaces of the maxillary central incisors before, at the end of the application of fluoride products (immediately after gel application, or after 4 or 24 h of varnish application) and after 7 and 28 days. Fluoride concentration in dental biofilm was also analyzed before and up to 28 days after initial application. The data were analyzed by 2-way ANOVA, considering treatment and time as factors. The APF-gel and FV-24h groups formed greater fluoride concentration on enamel than the FV-4h and the control group at the end of application (p=0.0001), with no difference from each other (p=0.99). The groups did not differ regarding fluoride in biofilm, fluid (p=0.73) and solids (0.40). In conclusion, fluoride varnish needs to remain in contact with the teeth for prolonged times (>4 h) to reach the same reactivity obtained by a 4-min application of APF-gel.

Impact of sleep on the microbiome of oral biofilms

Dysbiosis of the oral microbiome is associated with diseases such as periodontitis and dental caries. Because the bacterial counts in saliva increase markedly during sleep, it is broadly accepted that the mouth should be cleaned before sleep to help prevent these diseases. However, this practice does not consider oral biofilms, including the dental biofilm. This study aimed to investigate sleep-related changes in the microbiome of oral biofilms by using 16S rRNA gene sequence analysis. Two experimental schedules—post-sleep and pre-sleep biofilm collection—were applied to 10 healthy subjects. Subjects had their teeth and oral mucosa professionally cleaned 7 days and 24 h before sample collection. Samples were collected from several locations in the oral cavity: the buccal mucosa, hard palate, tongue dorsum, gingival mucosa, tooth surface, and saliva. Prevotella and Corynebacterium had higher relative abundance on awakening than before sleep in all locations of the oral cavity, whereas fluctuations in Rothia levels differed depending on location. The microbiome in different locations in the oral cavity is affected by sleep, and changes in the microbiome composition depend on characteristics of the surfaces on which oral biofilms form.

Study of the correlation between the clinical manifestations of the inflammatory periodontal diseases and the microbiome of periodontal pathogenic microflora in young representatives of a mixed population of the European region

The age of inflammatory periodontal disease (PD) manifestations has tended to decrease over the past decades. The study of the range of periodontal pathogens in young people and their influence on the PD manifestation contributes to the predictor identification for the early prevention of this pathology.The aim was to study the correlation between the range of periodontal pathogens in the dentoalveolar sulcus/periodontal pocket (DS/PC) contents and the clinical PD manifestations in young people.We examined 28 patients (23.1 ± 0.93 years) with dental biofilm-induced gingivitis (BG), 24 patients (30.7 ± 0.6 years) with aggressive periodontitis (AgP), and 87 clinically periodontally healthy patients (21.1 ± 0.49 years) (Control). The hygiene index and the periodontal status were determined in all patients. DNA of five periodontal pathogens was identified by PCR in the DS/PC contents. The statistical analysis was performed in Statistica 13.3. The critical significance level was p ≤ 0.05.DNA was not observed in 60.9 % of the control group samples and 7.1 % of the BG group samples. In other cases, the bacteria were found separately and as part of bacterial complexes. P.g. and T.f. were most often detected in all groups. P.g. (U = 474, р < 0.01) and A.a. (U = 209, р >< 0.05) significantly contributed to the plaque formation in the control group, T.d. – in BG and AgP groups (U = 37.5, р >< 0.05 and U = 34, р >< 0.05, respectively). In the AgP group, purulent discharge was more often recorded if T.d. was detected in the PC contents (χ2 = 5.53, р >< 0.05). T.f. + P.i. and P.g. + T.f. + P.i. complexes were exclusively associated with PD. Complexes of four bacteria were found only in the AgP group. The association of periodontal pathogens and their complexes with different PD forms was revealed.>< 0.01) and A.a. (U = 209, р <0.05) significantly contributed to the plaque formation in the control group, T.d. – in BG and AgP groups (U = 37.5, р <0.05 and U = 34, р <0.05, respectively). In the AgP group, purulent discharge was more often recorded if T.d. was detected in the PC contents (χ2 = 5.53, р <0.05). T.f. + P.i. and P.g. + T.f. + P.i. complexes were exclusively associated with PD. Complexes of four bacteria were found only in the AgP group.The association of periodontal pathogens and their complexes with different PD forms was revealed.

Differences in Effectiveness of Antibacterial Power Between Cocoa Peel Extract (Theobroma cocoa L.) and Benzalkonium Chloride 0.1% Against Staphylococcus aureus (In Vitro)

Background: Staphylococcus aureus is a gram-positive bacteria play a role in the formation of dental biofilm which iscausing dental caries. During tooth preparation, to stop the growth of bacteria, a cavity cleaning agent is given using achemical, namely Benzalkonium Chloride (BAC) 0.1%, but BAC has disadvantages including allergic reactions, tolerantmicrobes, and resistance. Therefore, it is hoped that there will be herbal ingredients that can be used as an alternative.Cocoa peel extract has active compounds of tannins, flavonoids, alkaloids, terpenoids, and saponins which haveantibacterial concentration 6% according to safe concentrations. Purpose: To explain the difference in the effectivenessof the antibacterial power of 6% cocoa peel extract and 0.1% BAC against Staphylococcus aureus (in vitro). Methods:This study was a laboratory experimental in vitro with the posttest only control group design. Using the diffusion methodfor Staphylococcus aureus that divided into two parts, 6% cocoa peel extract and 0.1% BAC. Each petri dish was givendisc paper dripped with 0.01 ml of each test material, then incubated for two days and observed the diameter of theinhibition zone. Results: The average diameter of the inhibition zone formed in the 6% cacao peel extract was 11.5288mm and BAC 0.1% was 18.2925 mm against Staphylococcus aureus. Conclusion: There was a significant difference inthe effectiveness of antibacterial power (p <0.05) between 6% cacao peel extract (Theobroma cacao L.) and 0.1% BACagainst Staphylococcus aureus (In Vitro).

Changes in Distribution of Dental Biofilm after Insertion of Fixed Orthodontic Appliances

Good oral hygiene is an important factor in oral and general health, especially in orthodontic patients, because fixed appliances might impede effective oral hygiene and thus increase the risks of tooth decay, periodontal disease and general health complications. This study investigated the impact of fixed orthodontic appliances on the distribution of dental biofilm in teenagers. Supragingival plaque was assessed at T0, T1 and T2. The distribution of the biofilm was analyzed. Approximal Plaque Index (API) and Bonded Bracket Index (BBI) were used to measure the presence of dental plaque. After insertion of the fixed appliance, the dental plaque indices values in the orthodontically treated group were significantly higher (p < 0.05) than in the control group. Fixed orthodontic appliances caused significant changes in the distribution of the biofilm. This was characterized by the change of location of the dental plaque. In the orthodontic group, we observed an increase in the amount of the supragingival plaque on the vestibular surface of the teeth.

A Challenge of COVID—19: Associated Infective Endocarditis with Streptococcus gordonii in a Young Immunocompetent Patient

The COVID-19 pandemic is a new challenge for the diagnosis and treatment of infective endocarditis (IE). Fever and other unspecific symptoms of coronaviral infection could be misleading or masking its manifestations. We present the case of a young patient admitted for persistent fever, profuse sweating, headache, articular pain, myalgias, and weight loss. She reported regression taste and smell disorders compared to a month earlier when diagnosed with moderate COVID-19 pneumonia. While the RT-PCR SARS-COV-2 test was positive, she was admitted to a COVID-19 ward. Investigations of febrile syndrome revealed two positive blood cultures with Streptococcus gordonii and the presence of vegetations on the aortic valve, supporting a certain diagnosis of IE. After six weeks of antibiotic treatment, the patient had clinical and biologic favorable outcomes. Streptococcus gordonii is a common commensal related to the dental biofilm, although there were no caries in our patient. The influence of COVID-19 infection on the human microbiome by modifying the virulence of some commensal germs may be a risk factor for IE pathogenesis on native valves and requires the vigilance of clinicians for suspicion of this disease.

Potential of Prebiotic D-Tagatose for Prevention of Oral Disease

Recent studies have shown phenotypic and metabolic heterogeneity in related species including Streptococcus oralis, a typical oral commensal bacterium, Streptococcus mutans, a cariogenic bacterium, and Streptococcus gordonii, which functions as an accessory pathogen in periodontopathic biofilm. In this study, metabolites characteristically contained in the saliva of individuals with good oral hygiene were determined, after which the effects of an identified prebiotic candidate, D-tagatose, on phenotype, gene expression, and metabolic profiles of those three key bacterial species were investigated. Examinations of the saliva metabolome of 18 systemically healthy volunteers identified salivary D-tagatose as associated with lower dental biofilm abundance in the oral cavity (Spearman’s correlation coefficient; r = -0.603, p = 0.008), then the effects of D-tagatose on oral streptococci were analyzed in vitro. In chemically defined medium (CDM) containing D-tagatose as the sole carbohydrate source, S. mutans and S. gordonii each showed negligible biofilm formation, whereas significant biofilms were formed in cultures of S. oralis. Furthermore, even in the presence of glucose, S. mutans and S. gordonii showed growth suppression and decreases in the final viable cell count in a D-tagatose concentration-dependent manner. In contrast, no inhibitory effects of D-tagatose on the growth of S. oralis were observed. To investigate species-specific inhibition by D-tagatose, the metabolomic profiles of D-tagatose-treated S. mutans, S. gordonii, and S. oralis cells were examined. The intracellular amounts of pyruvate-derived amino acids in S. mutans and S. gordonii, but not in S. oralis, such as branched-chain amino acids and alanine, tended to decrease in the presence of D-tagatose. This phenomenon indicates that D-tagatose inhibits growth of those bacteria by affecting glycolysis and its downstream metabolism. In conclusion, the present study provides evidence that D-tagatose is abundant in saliva of individuals with good oral health. Additionally, experimental results demonstrated that D-tagatose selectively inhibits growth of the oral pathogens S. mutans and S. gordonii. In contrast, the oral commensal S. oralis seemed to be negligibly affected, thus highlighting the potential of administration of D-tagatose as an oral prebiotic for its ability to manipulate the metabolism of those targeted oral streptococci.

Meta-Analysis Using NGS Data: The Veillonella Species in Dental Caries

Objectives: In light of recent technological advances in Next-generation sequencing (NGS) and the accumulation of large, publicly available oral microbiome datasets, the need for meta-analysing data on caries microbiome is becoming feasible and essential. A consensus on the identification of enriched organisms in cariogenic dysbiotic biofilms would be reached. For example, members of the Veillonella genus have been detected in caries biofilms, and may have an underestimated contribution to the dysbiotic process. Hence, we aimed to determine the abundance of Veillonella species in dental caries in studies using NGS data.Materials and Methods: Analysis was performed according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (registered at PROSPERO: CRD42020204150). Studies investigating microbial composition in saliva, dental biofilm, or carious dentin were included. Six databases and grey literature were searched. Two independent reviewers selected the papers and assessed the methodological quality.Results: Searches retrieved 1,323 titles, from which 38 studies were included in a qualitative synthesis, comprising a total of 1,374 caries and 745 caries-free individuals. Most studies analysed 16S rRNA amplicons, and only 5 studies used shotgun metagenomics and metatranscriptomics. A geographical bias was observed. The methodological quality was downrated in 81.5% of the studies due to the lack of criteria for defining cases and standard criteria used for measurement of the condition in a reliable way. Six studies on early childhood caries (ECC) were meta-analysed, confirming a significant enrichment of Veillonella spp. in caries-associated biofilms (but not saliva) when compared to caries-free controls [mean difference: 2.22 (0.54–3.90); p = 0.01].Conclusions:Veillonella spp. is more abundant in individuals suffering with ECC when compared to caries-free controls (very low evidence certainty), and should be considered for further studies to observe their metabolism in dental caries. There is an urgent need for a consensus in methodologies used to allow for more rigorous comparison between NGS studies, particularly including clinical data and details of caries diagnosis, as they are currently scarce. Inconsistent reporting on the NGS data affected the cross-study comparison and the biological connexions of the relative abundances on caries microbiome.