Characterizing Peri-Implant and Sub-Gingival Microbiota through Culturomics. First Isolation of Some Species in the Oral Cavity. A Pilot Study

Comparison between twin block appliance and mandibular advancement on clear aligners in the improvement of airway dimension: incremental versus maximum bite advancement

Objective

The aim of the present retrospective study was to compare the changes resulting from treatment using the MA and the TB with special regard to the oro-and naso-pharyngeal sagittal airway dimensions in subjects with dentoskeletal Class II malocclusions and positive history of Sleep Disorder Breathing (SDB) diagnosed through the Pediatric Sleep Questionnaire (PSQ).

Materials and methods

This retrospective study involved 2 groups of subjects: patients treated with Twin Block (TB group: n = 22, 10 males, 12 females; mean age 12.0 ± 1.3 years) and patients treated with Mandibular Advancement (MA group: n = 23, 11 males, 12 females; mean age 12.2 ± 1.1 years). Pretreatment (T1) and posttreatment (T2) lateral cephalograms were analyzed. All patients underwent the PSQ to diagnose SDB.

Results

In both treated groups there was an increase in the airways dimensions and an improvement in symptoms related SDB. The statistical comparison of the changes between T1 and T2 in the TB group showed a significant increment in upper airway size (PNS-AD2, +1.50 mm + -3.30; McNamara's upper pharynx dimension, +2.21 + -4.21) after active treatment. The MA group showed similar results during active treatment with a significant increase in both upper (PNS-AD2, +2.72 + -2.65; McNamara's upper pharynx dimension, +2.97 + -3.07) and lower (PNS-AD1, +2.17 mm + -3.54) airway size.

Conclusions

Despite the different structure of these two devices and the different advancement protocols, both appliances were valuable as a suitable treatment option for Class II patients with respiratory disorders, inducing an increase of upper and lower airway size and a significant reduction in diurnal symptoms.

Isolation of phages against Streptococcus species in the oral cavity for potential control of dental diseases and associated systemic complications

Dental infections and systemic complications caused by Streptococcus species in the oral cavity are increasingly exhibiting resistance to commonly used antibiotics, posing a potential threat to global public health. Phage therapy may offer a superior alternative, given that bacteriophages can be easily isolated and rapidly replicate in large numbers. In this study, six Streptococcus species from the oral cavity were characterized. Bacteriophages isolated from wastewater using five of these species as hosts produced plaques ranging from 0.2 to 2.4 mm in size. The phages demonstrated stability within a temperature range of 4 ℃ to 37 ℃. However, at temperatures exceeding 45 ℃, a noticeable reduction in bacteriophage titer was observed. Similarly, the phages showed greater stability within a pH range of 5 to 10. The isolated phages exhibited latency periods ranging from 15 to 20 min and had burst sizes varying from 10 to 200 viral particles. This study supports the potential use of bacteriophages in controlling infections caused by Streptococcus species.

Omics for deciphering oral microecology

The human oral microbiome harbors one of the most diverse microbial communities in the human body, playing critical roles in oral and systemic health. Recent technological innovations are propelling the characterization and manipulation of oral microbiota. High-throughput sequencing enables comprehensive taxonomic and functional profiling of oral microbiomes. New long-read platforms improve genome assembly from complex samples. Single-cell genomics provides insights into uncultured taxa. Advanced imaging modalities including fluorescence, mass spectrometry, and Raman spectroscopy have enabled the visualization of the spatial organization and interactions of oral microbes with increasing resolution. Fluorescence techniques link phylogenetic identity with localization. Mass spectrometry imaging reveals metabolic niches and activities while Raman spectroscopy generates rapid biomolecular fingerprints for classification. Culturomics facilitates the isolation and cultivation of novel fastidious oral taxa using high-throughput approaches. Ongoing integration of these technologies holds the promise of transforming our understanding of oral microbiome assembly, gene expression, metabolites, microenvironments, virulence mechanisms, and microbe-host interfaces in the context of health and disease. However, significant knowledge gaps persist regarding community origins, developmental trajectories, homeostasis versus dysbiosis triggers, functional biomarkers, and strategies to deliberately reshape the oral microbiome for therapeutic benefit. The convergence of sequencing, imaging, cultureomics, synthetic systems, and biomimetic models will provide unprecedented insights into the oral microbiome and offer opportunities to predict, prevent, diagnose, and treat associated oral diseases.

“Bacterial Consortium”: A Potential Evolution of Fecal Microbiota Transplantation for the Treatment of Clostridioides difficile Infection

Fecal microbiota transplantation (FMT) consists of infusion of feces from a donor to a recipient patient in order to restore the resident microbial population. FMT has shown to be a valid clinical option for Clostridioides difficile infections (CDI). However, this approach shows several criticalities, such as the recruiting and screening of voluntary donors. Our aim was to evaluate the therapeutic efficacy of a synthetic bacterial suspension defined “Bacterial Consortium” (BC) infused in the colon of CDI patients. The suspension was composed by 13 microbial species isolated by culturomics protocols from healthy donors' feces. The efficacy of the treatment was assessed both clinically and by metagenomics typing. Fecal samples of the recipient patients were collected before and after infusion. DNA samples obtained from feces at different time points (preinfusion, 7, 15, 30, and 90 days after infusion) were analyzed by next-generation sequencing. Before infusion, patient 1 showed an intestinal microbiota dominated by the phylum Bacteroidetes. Seven days after the infusion, Bacteroidetes decreased, followed by an implementation of Firmicutes and Verrucomicrobia. Patient 2, before infusion, showed a strong abundance of Proteobacteria and a significant deficiency of Bacteroidetes and Verrucomicrobia. Seven days after infusion, Proteobacteria strongly decreased, while Bacteroidetes and Verrucomicrobia increased. Metagenomics data revealed an “awakening” by microbial species absent or low concentrated at time T0 and present after the infusion. In conclusion, the infusion of selected bacteria would act as a trigger factor for “bacterial repopulation” representing an innovative treatment in patients with Clostridioides difficile infections.

Effect of Orthodontic Appliances on the Oral Environment and Microbiome

Orthodontic treatment is an appliance-intensive endeavor, where an array of mechanical devices is used to bring about tooth movement. By virtue of remaining in close proximity to the enamel, gingiva and periodontal ligament intra-orally over a prolonged period of time, orthodontic appliances have a significant impact on the paradental tissues, oral environment and oral microbiome. Orthodontic appliances by acting as anchors for biofilm and plaque formation, accumulate bacteria and other micro-organisms in amounts unfavorable for maintenance of healthy equilibrium. The resulting loss of balance in the oral microbiome causes dysbiosis which manifests clinically as increased enamel demineralization, dental caries and periodontal disease. Mechanical removal of the accumulated plaque by maintaining rigorous oral hygiene has been proven to be the single most important factor to mitigate the harmful effects of dysbiosis. This review investigates how each of the various components of the orthodontic appliances, different types of appliances and unique surface properties of biomaterials have contributory effects at the interface of orthodontic biomaterials and oral biology. The information thus obtained will be critical in instituting the best diagnostic and therapeutic measures at the clinical level. It will also be instrumental in devising improvements and providing new directions for future research in general and precision orthodontics in particular.

Rummeliibacillus suwonensis: First Time Isolation from Human Feces by Culturomics

Gut microbiota is a complex ecosystem composed by trillions of microorganisms that are crucial for human health or disease status. Currently, there are two methodological options to explore its complexity: metagenomics and culturomics. Culturomics is an approach that uses multiple culture conditions (days of incubation, enrichment factors and growth temperature) and MALDI-TOF mass spectrometry for the identification of bacterial species and sequencing when this method fails. In this paper, we describe how Colturomic's protocol has allowed the first isolation in human sample of Rummeliibacillus suwonensis, a Gram positive, facultative anaerobe bacterium. The bacterium was isolated from feces of a 69 years old male with amyotrophic lateral sclerosis (ALS) recruited for a clinical trial assessing safety and efficacy of fecal microbiota transplantation in ALS. The first isolation of the microorganism dates back to 2013 from the soil of a South Korean mountain area. In this report, morphological description, biochemical characterization and antibiotic susceptibility tests were performed to outline the bacterial properties.

Prevalence of Bone Loss in Mandibular Future Abutment Teeth among Diabetic and Non-Diabetic Patients: A Retrospective Case-Control Study

Objective:

This study aimed to compare the prevalence of bone loss in lower permanent premolars and canines, which can serve as abutments for future prostheses, among diabetic and non-diabetic patients.

Materials and Methods:

In this retrospective case-control study, records of patients who visited the dental clinics of Imam Abdulrahman Bin Faisal University were used. Inclusion criteria were the presence of a complete periodontal chart, full mouth radiographs, and past medical history (presence of DM, hypertension, and/or coronary heart disease). The criteria for exclusion were the reporting of malignancy, pregnancy, breastfeeding, or taking of the medications that affect bone turnover, periodontal surgery within the past year, absence of radiographs with good quality, and antibiotic use within 3 months prior to the dental visit. Demographical data, including gender and age, past medical history (diabetic state), and periodontal diagnosis, were collected. The severity of periodontal disease, radiographic bone loss (RBL), and its pattern were also assessed.

Results:

Out of 400 records, 363 patient files were included. Of those, almost 36% were males and 64% were females. The patients’ age was ranging from 16 to 82 years. About 34% of the patients were diagnosed with generalized periodontitis while 22% had localized periodontitis. With regards to the severity of the cases, the prevalence was equally distributed between mild (37%) and moderate periodontitis (38%), while 25% were diagnosed with severe periodontitis. A total of 22% of the patients were diabetic, which showed an increase in the severity of bone loss by an average of 31% across the selected teeth (mandibular canines and premolars). The pattern of bone loss was higher in the mandibular incisors, followed by the canines and the premolars. Multiple regression models showed that non-diabetics were significantly less likely to have bone loss in all the selected teeth and the male patients had 2 times the likelihood of having bone loss. Although the mandibular canines have the highest root length in the mandible, they were the most affected by bone loss in diabetic patients with periodontitis.

Conclusion:

Results of this study suggested that mandibular premolars were the teeth least affected by bone loss in both, diabetic and non-diabetic groups. Therefore, they can be considered the most suitable teeth to be used as abutments for the future prosthesis.

Cultivation and Genomic Characterization of the Bile Bacterial Species From Cholecystitis Patients

The microbes in human bile are closely related to gallbladder health and other potential disorders. Although the bile microbial community has been investigated by recent studies using amplicon or metagenomic sequencing technologies, the genomic information of the microbial species resident in bile is rarely reported. Herein, we isolated 138 bacterial colonies from the fresh bile specimens of four cholecystitis patients using a culturome approach and genomically characterized 35 non-redundant strains using whole-genome shotgun sequencing. The bile bacterial isolates spanned 3 classes, 6 orders, 10 families, and 14 genera, of which the members of Enterococcus, Escherichia-Shigella, Lysinibacillus, and Enterobacter frequently appeared. Genomic analysis identified three species, including Providencia sp. D135, Psychrobacter sp. D093, and Vibrio sp. D074, which are not represented in existing reference genome databases. Based on the genome data, the functional capacity between bile and gut isolates was compared. The bile strains encoded 5,488 KEGG orthologs, of which 4.9% were specific to the gut strains, including the enzymes involved in biofilm formation, two-component systems, and quorum-sensing pathways. A total of 472 antibiotic resistance genes (ARGs) were identified from the bile genomes including multidrug resistance proteins (42.6%), fluoroquinolone resistance proteins (12.3%), aminoglycoside resistance proteins (9.1%), and β-lactamase (7.2%). Moreover, in vitro experiments showed that some bile bacteria have the capabilities for bile salt deconjugation or biotransformation (of primary bile acids into secondary bile acids). Although the physiological or pathological significance of these bacteria needs further exploration, our works expanded knowledge about the genome, diversity, and function of human bile bacteria.

Cleaning Teeth Reduces the Inflammatory Response of Macrophages to Acid Dentine Lysate

Particulate autogenous tooth roots are used for alveolar bone augmentation surgery; however, dental plaque may provoke an inflammatory response that may counteract the desired graft consolidation process. Traditional mechanical cleaning of extracted teeth may be of support to lower a possible inflammatory response of the autograft. To test this assumption, extracted porcine teeth were left either uncleaned or underwent mechanical cleaning with a toothbrush and toothpaste before being fragmented and subjected to acid lysis, termed as unclean acid dentine lysate (ucADL) and clean acid dentine lysate (cADL), respectively. The inflammatory responses of murine macrophage RAW 264.7 cells being exposed to the respective acid dentine lysates were evaluated at the level of inflammatory gene expression and IL6 immunoassays. We report here that acid lysates obtained from uncleaned teeth provoked a robust increase in IL1β, IL6, and COX2 in RAW 264.7 cells. The mechanical removal of dental plaque significantly reduced the inflammatory response. Consistently, Limulus tests revealed that tooth cleaning lowers the presence of endotoxins in dentine lysates. To further prove the involvement of endotoxins, a toll-like receptor 4 (TLR4) inhibitor TAK242 was introduced. TAK242 abolished the inflammatory response provoked by acid lysates obtained from uncleaned teeth in RAW 264.7 cells. Moreover, nuclear translocation and phosphorylation of the TLR4 downstream NFκB-p65 were attenuated at the presence of cleaned versus uncleaned dentine lysates. Taken together, our data support the importance of dental plaque removal of teeth being extracted for alveolar bone augmentation surgery.

Marginal Bone Loss in Implants with External Connection versus Internal Conical Connection Prior to Prosthetic Loading. A Randomized Clinical Study

Introduction: The prosthetic connection of implants has been related to the loss of marginal bone. The aim of this study was to evaluate bone loss around external connection (EC) and internal conical connection (ICC) implants prior to prosthetic loading. Material and methods: A randomized clinical trial (RCT) was carried out, with a sample size of 93 implants (31 EC and 62 ICC) placed in 27 patients. Radiological controls were performed and stability was measured by resonance frequency analysis (RFA) on the day of placement, at 1 month and at 4 months after the placement. Results: Bone loss in EC implants was not statistically different than in ICC implants between the time of placement (T0) and the subsequent month (T1): (EC = 0.18 mm and ICC = 0.17 mm). Between one month (T1) and four months (T2): (EC = 0.39 mm and ICC = 0.19 mm) this difference was highly significant (p = 0.00). Bone loss between T0 and T2 was significantly lower in the ICC (EC = 0.57 mm and ICC = 0.36 mm), (p = 0.01). The overall success rate of the implants was 97.8%. The stability of the implants increased from 70.69 (T0) to 73.91 (T1) and 75.32 (T2). Conclusions: ICC showed less bone loss up to the time of prosthesis placement. Such bone loss did not have a significant impact on bone stability. Long term RCTs are needed to demonstrate whether this bone loss, which is more pronounced at the beginning in EC, tends to stabilize and equate to ICC.

Ethanol extract of Schinus molle L. (Molle) and Erythroxylum coca Lam (Coca): Antibacterial Properties at Different Concentrations against Streptococcus mutans: An In Vitro Study

OBJECTIVE

The aim of this study was to compare in vitro the antibacterial activity of an ethanol extract of Erythroxylum coca Lam (EEE) and Schinus molle L. (EES) at 50% and 75% versus Streptococcus mutans ATCC 25175.

MATERIALS AND METHODS

This was a prospective, comparative, longitudinal experimental study. The ethanol extract of coca and molle leaves was obtained by the vacuum filtration method at concentrations of 50% and 75% and was compared with a positive control (0.12% chlorhexidine). Streptococcus mutans strains were isolated in a culture medium (Mitis Salivarius Agar) ideal for the growth of bacterial colonies. The antibacterial activity of the ethanol extract was carried out following the Kirby-Bauer disk-diffusion method in Mueller-Hinton agar to measure bacterial sensitivity. A value of P < 0.05 was considered statistically significant.

RESULTS

Evaluation of the antibacterial effect of EEE and EES at 24 and 48 h showed that a concentration of 75% for both groups had the highest antimicrobial activity against S. mutans (11.2 ± 0.7 mm; 11.6 ± 0.5 mm and 11.3 ± 0.7 mm; 11.8 ± 0.5 mm, respectively). So, the results have shown that the concentration of EEE and EES of 75% has a greater efficacy than the concentration of 50%, but both concentrations are not as effective as chlorhexidine.

CONCLUSION

EEE and EES at concentrations of 50% and 75% present antibacterial activity against S. mutans ATCC 25175.

Clinical Performance of Short Expandable Dental Implants for Oral Rehabilitation in Highly Atrophic Alveolar Bone: 3-year Results of a Prospective Single-Center Cohort Study

Background and Objectives: Oral health-related quality of life (OHRQOL) is compromised during the post-implant healing period, especially when vertical augmentation is required. A long-term trial sought to evaluate a short dental implant system with an apically expandable macro-design. Materials and Methods: Over 4.5 years, patients with limited vertical alveolar bone were consecutively recruited into this prospective cohort study. Implant success rate, OHRQOL (Oral Health Impact Profile (OHIP)-14), implant stability, and crestal bone changes were evaluated. Results: Data from 30 patients (mean age: 64.6 years, range 44–83) were analyzed, which related to 104 implants (53 in the maxilla, 51 in the mandible). Over the mean follow-up (42.6 ± 16.4 months), the implant success rate was 94.7% in the mandible (two implants lost) and 83.6% in the maxilla (four implants lost; p = 0.096), and the prosthetic success rate was 100%. The median OHIP-14 scores improved from 23 (interquartile range (IQR) 9–25.5) to 2 (IQR 0–5; p < 0.001). The mean implant stability quotient (ISQ) was 71.2 ± 10.6 for primary stability and 73.7 ± 13.3 (p = 0.213) for secondary stability, without significant maxilla-versus-mandible differences (p ≥ 0.066). Compared to the baseline, median crestal bone changes after loading were 1.0 mm (IQR 0–1.3) and 1.0 mm (IQR 0.2–1.2) in the maxilla and mandible (p = 0.508), respectively, at the end of the first year, 1.1 mm (IQR 0–1.3) and 1.0 mm (IQR 0.1–1.2) (p = 0.382), respectively, at the end of the second year, and 1.2 mm (IQR 0–1.9) and 1.1 mm (IQR 0.1–1.2) (p = 0.304), respectively, at the end of the third year. Conclusions: In patients with limited vertical bone height, short implants with optimized macro-design constitute a reliable method for functional rehabilitation, avoiding extensive alveolar bone augmentation.