Hub genes and pathways related to caries-free dental biofilm: clinical metatranscriptomic study.

OBJECTIVE: This study aimed to evaluate the microbial functional profile of biofilms related to caries-free (CF, n = 6) and caries-arrested (CI, n = 3) compared to caries-active (CA, n = 5) individuals. MATERIALS AND METHODS: A metatranscriptomic was performed in supragingival biofilm from different clinical conditions related to caries or health. Total RNA was extracted and cDNAs were obtained and sequenced (Illumina HiSeq3000). Trimmed data (SortMeRNA) were submitted to the SqueezeMeta pipeline in the co-assembly mode for functional analysis and further differential gene expression analysis (DESeq2) and weighted gene co-expression network analysis (WCGNA) to explore and identify gene modules related to these clinical conditions. RESULTS: A total of 5303 genes were found in the metatranscriptomic analysis. A co-expression network identified the most relevant modules strongly related to specific caries status. Correlation coefficients were calculated between the eigengene modules and the clinical conditions (CA, CI, and CF) discriminating multiple modules. CA and CI showed weak correlation coefficient strength across the modules, while the CF condition presented a very strong positive correlation coefficient (r = 0.9, p value = 4 × 10-9). Pearson's test was applied to further analyze the module membership and gene significance in CF conditions, and the most relevant were HSPA1s-K03283, Epr- K13277, and SLC1A-K05613. Gene Ontology (GO) shows important bioprocesses, such as two-component system, fructose and mannose metabolism, pentose and glucuronate interconversions, and flagellar assembly (p-adjust < 0.05). The ability to use different carbohydrates, integrate multiple signals, swarm, and bacteriocin production are significant metabolic advantages in the oral environment related to CF. CONCLUSIONS: A distinct functional health profile could be found in CF, where co-occurring genes can act in different pathways at the same time. Genes HSPA1s, Epr, and SLC1A may be appointed as potential biomarkers for caries-free biofilms. CLINICAL RELEVANCE: Potential biomarkers for caries-free biofilms could contribute to the knowledge of caries prevention and control.

A scoping review on hyposalivation associated with systemic conditions: the role of physical stimulation in the treatment approaches.

BACKGROUND: Several systemic conditions can result in distinct degrees of salivary gland damage and consequent hypofunction. The development of successful management schemes is highly challenging due to the complexity of saliva. This study aimed to systematically map the literature on the physical stimulation of salivary glands for hyposalivation management and the response of individuals according to different systemic conditions causing salivary impairment. METHODS: A systematic search in the literature was performed. Two reviewers independently selected clinical trials, randomized or not, that used physical stimulation to treat hyposalivation caused by systemic conditions. Studies evaluating healthy subjects without hyposalivation were included as controls. Single-arm clinical studies or case series were also included for protocol mapping (PRISMA extension for scoping reviews). RESULTS: Out of 24 included studies, 10 evaluated healthy subjects, from which 9 tested transcutaneous electrical nerve stimulation (TENS) and 1 tested acupuncture and electroacupuncture. Fourteen studies evaluated individuals with hyposalivation: 6 applied TENS, 6 applied low-level laser therapy (LLLT), and 2 applied acupuncture, carried out in post-chemotherapy, medication use, postmenopausal women, hemodialysis patients, smokers, diabetics, Sjögren's syndrome (SS). All showed increased salivation after treatment, except for two LLLT studies in individuals with SS. CONCLUSIONS: Among the different patient groups, individuals with Sjögren's syndrome (SS) exhibited the poorest responses, while those with medication-induced hyposalivation demonstrated the most favorable treatment outcomes, independently of the management strategy for saliva stimulation. It means that physical stimulation of salivary glands holds promise as an alternative for managing hyposalivation in cases of reversible gland damage. However, to make informed decisions in current practice, it is necessary to conduct new well-designed randomized clinical trials with appropriate methodologies.

Dental education profile in COVID-19 pandemic: A scoping review.

INTRODUCTION: This scoping review aimed to determine the frequency of different teaching methodologies, tools and platforms applied in dental education during the COVID-19 pandemic. MATERIALS AND METHODS: The search strategy was performed in six databases and grey literature. A total of 28 questionnaire-based studies were included, without language or time restriction, from 20 different countries. RESULTS: Six thousand five hundred sixty-five participants were assessed: 84% undergraduates, 9% of faculty members, 5% of postgraduate students/residents/trainees and 2% of dental schools/residency programs. The pooled eligible data for teaching methodologies were 62% of a combination of different methods (95% CI, 35.5% to 82.3%), 23% a combination of synchronous and asynchronous formats (95% CI, 8.2% to 50.2%) and 15% for only synchronous lectures (95% CI, 4.3% to 42.2%). The reported tools were laptops (40%), smartphones (40%), tablets (40%), desktops (20%), Blackboard (20%), Respondus Lockdown Browser (20%), eProctor (20%) and PowerPoint (20%). The most used platforms were Zoom (70.6%), Microsoft Teams (23.5%) and Cisco Webex (23.5%). A better time management (17.9%; 95% CI, 7.9% to 35.6%) and the possibility of revision with additional notes (14.3%; 95% CI, 5.7% to 31.5%) was the greatest advantages related to dental e-learning, while the increased levels of anxiety/stress/burnout/exhaustion (35.7%; 95% CI, 21% to 54.2%) and internet connection problems (35.7%; 95% CI, 21% to 54.2%) was the most cited disadvantages. CONCLUSION: This scoping review showed promising blended teaching methodologies, tools and platforms in the dental education profile. The evidence suggests that e-learning technologies can widely contribute to dental education during the COVID-19 pandemic. Therefore, this study makes a major contribution to research by assessing the impact of COVID restrictions on dental education and further studies are needed to identify how restrictions in dental practice will affect future professionals.

Streptococcus mutans Gene Expression and Functional Profile in Root Caries: An RNA-Seq Study.

The literature is still scarce on studies describing Streptococcus mutans global gene expression under clinical conditions such as those found on complex biofilms from sound root surfaces (SRS) and carious root surfaces (RC). This study aimed to investigate the S. mutans gene expression and functional profile within the metatranscriptome of biofilms from SRS and from RC in an attempt to identify enriched functional signatures potentially associated with the healthy-to-disease transitioning process. Total RNA was extracted, and prepared libraries (SRS = 10 and RC = 9) were paired-end sequenced using the Illumina HiSeq2500. A read count assigned to each gene of the S. mutans UA159 strain was obtained. Differentially expressed genes (DEG) between SRS and RC were identified using the DESeq2 R package, and weighted gene co-expression network analysis (WGCNA) was performed to explore and identify functional modules related to SRS and RC. We found seventeen DEG between SRS and RC samples, with three overexpressed in RC and related to membrane protein, alanyl-tRNA synthetase, and GTP-binding protein, with the remaining ones overexpressed in SRS samples and related to hypothetical protein, transposon integrase, histidine kinase, putative transporter, bacteriocin immunity protein, response regulator, 6-phospho-beta-galactosidase, purine metabolism, and transcriptional regulator. Key-functional modules were identified for SRS and RC conditions based on WGCNA, being 139 hub genes found on SRS key-module and 17 genes on RC key-module. Functional analysis of S. mutans within the metatranscriptome of biofilms from sound root and from carious root revealed a similar pattern of gene expression, and only a few genes have been differentially expressed between biofilms from SRS and those from root carious lesions. However, S. mutans presented a greater functional abundance in the carious lesion samples. Some functional patterns related to sugar (starch, sucrose, fructose, mannose, and lactose) and heterofermentative metabolisms, to cell-wall biosynthesis, and to acid tolerance stress seem to be enriched on carious root surfaces, conferring ecological advantages to S. mutans. Altogether, the present data suggest that a functional signature may be associated with carious root lesions.

Meta-analyses on the Periodontal Archaeome.

Recently, we have published a scoping review on the oral archaeome, showing that these microorganisms inhabit various oral niches, including periodontal sites. In order to reinforce the importance of the Archaea domain and alert the scientific community about the importance of inter-domain relationships in oral dysbiosis, we have performed meta-analyses evaluating the prevalence of archaea in periodontal diseases (PROSPERO protocol: CRD42020213109). A systematic search in the literature was conducted in several databases and in grey literature, retrieving 30 reports on periodontal archaeome, published from 1980 to 2020. The methodological quality of included studies and the certainty of evidence were evaluated by using validated tools. Most studies focused on the detection of methanogens, revealing that the diversity of the periodontal archaeome is currently underestimated. Two meta-analyses concluded that individuals with periodontitis are prone to have archaeal-positive subgingival biofilms when compared to periodontally healthy individuals (OR 6.68, 95% CI 4.74-9.41 for 16S rRNA gene analysis and OR 9.42, 95% CI 2.54-34.91 for mcrA gene analysis). Despite the archaeal enrichment in sites with periodontitis, less than half of the individuals with periodontitis tested positive for archaeal DNA (general estimative of 46%; 95% CI 36-56%). Conventional treatment for periodontitis reduced the archaeal population, but systemic antibiotics used as adjunctive therapy did not increase its effectiveness. Hence, it could conceivably be hypothesised that archaea are secondary colonizers of areas with dysbiosis, probably flourishing in the inflammatory environment. Due to their lower prevalence, archaeal cells are probably underestimated by the current detection protocols. It may also be speculated that archaea do not have a single central role in the infection, with bacterial cells directly involved in that role. New studies are necessary, with different methodological approaches, to explore the underestimated diversity of the oral archaeome.

Impact of detection criteria on coronal and root caries estimates in adults with and without type 2 diabetes mellitus.

OBJECTIVE: To compare caries prevalence and extent in adults with or without diabetes mellitus (DM) according to different caries detection criteria (WHO, ICDAS, and Nyvad). MATERIALS AND METHODS: A cross-sectional study was carried out including 122 individuals, 44 without DM and 78 with type 2 DM. Trained and calibrated examiners performed a visual-tactile inspection to record coronal and root caries lesions (weighted kappa > 0.7). Caries prevalence and extent were calculated according to the WHO (only cavitated lesions, missing and filled surfaces), ICDAS (all non-cavitated and cavitated lesions, missing and filled surfaces), and Nyvad (only active lesions, non-cavitated and cavitated). For root caries, lesions were classified as active or inactive. RESULTS: A significantly higher overall caries experience (DMF-S) was observed among patients with DM when the WHO (RR = 1.37; 95% CI = 1.09-1.71) and the ICDAS (RR = 1.32; 95% CI = 1.07-1.62) criteria were adopted. No difference between groups was found when the Nyvad criterion was used, although a low study power was observed in this comparison. Estimates for root caries showed a higher prevalence (PR = 2.65; 95% CI = 1.05-6.70) and risk (RR = 6.02, 95% CI = 1.81-20.00) of total D-S among diabetic patients. CONCLUSIONS: DM can predispose individuals to a higher number of root caries lesions, independently of their past caries experience. Missing teeth can overestimate caries extent in individuals with DM. CLINICAL RELEVANCE: Individuals with DM should be monitored for the prevention and control of root caries. It is recommended to splitting missing teeth from the caries estimates in studies involving adults, particularly diabetic ones.

Assessment of the Oral Health Impact Profile (OHIP-14) improvement of different treatments for dentin hypersensitivity in noncarious cervical lesions-a randomized clinical study.

OBJECTIVES: To assess the improvement on oral health-related quality of life (OHRQoL) of individuals with cervical dentin hypersensitivity (CDH) with the noncarious cervical lesion (NCCLs) subjected to different treatments. MATERIAL AND METHODS: A single-blind randomized clinical trial was conducted with patients (n = 74) randomly allocated into three groups according to the treatment performed: PO, potassium oxalate (Oxa-Gel BF); LL, low-power laser irradiation; and POLL, potassium oxalate (Oxa-Gel BF) associated with low-power laser irradiation. The treatments were applied in four steps, weekly. The questionnaire Oral Health Impact Profile (OHIP-14) was applied before initiating and immediately after the fourth session. The greater the sum of the score, the smaller the measurement of OHRQoL. RESULTS: The total mean values of the variables at the final moment were significantly lower than the initial one for all dimensions (p value ranging from < 0.001 to 0.006). Furthermore, the OHIP-14 scores final analysis between the groups indicated that the POLL group compared to LL had a significantly lower final score for the functional limitation (p = 0.009), physical pain (p = 0.049), and psychological discomfort (p = 0.035) dimensions and that group PO compared to group LL had a significantly lower final score for the functional limitation dimension (p = 0.024). CONCLUSIONS: There was a reduction in the OHIP-14 score for all dimensions, indicating an improvement in patients' quality of life after the use of desensitizing therapies. Patients in group LL had a higher functional limitation, physical pain, and psychological discomfort. CLINICAL RELEVANCE: This study indicated improvement of desensitizing therapies for CDH to improve patients' OHRQoL. TRIAL REGISTRATION: This trial was registered in the Brazilian Clinical Trials Registry Platform (REBEC protocol number RBR-4ybjmt).

Functionally Active Microbiome in Supragingival Biofilms in Health and Caries.

The oral microbiome is unique at inter and intra-individual levels at various sites due to physical and biological factors. This study aimed to compare the bacterial composition of supragingival biofilms collected from enamel sites with different caries activity, from active and inactive-caries subjects, and from caries-free (CF) subjects. Twenty-two individuals (aged between 13 and 76 years old; med = 23.5 years old) were allocated into 3 groups: caries-active (CA) (n = 10), caries-inactive (CI) (n = 6), and CF (n = 6). From the CA group, 3 sites were sampled: CA (active non-cavitated lesion), CI (inactive non-cavitated lesion), and sound enamel surface (S). From the subjects of the CI group, biofilm from a CI lesion was collected (INCL), while for the CF subjects, a pool of biofilm from sound enamel surfaces was sampled. The total RNA was extracted, and cDNA libraries were prepared and paired-end sequenced (Illumina HiSeq 3,000). Final dental biofilm samples analysed from CA was 16 (ANCL-CA = 6, INCL-CA = 4, S-CA = 6); from CI, 3 (INCL-CI = 3); and from CF, 6 (S-CF = 6) (some samples were lost by insufficient genetic material). Read sequences were processed and analysed using the Metagenomics RAST server. High-quality sequences (3,542,190) were clustered into operational taxonomic units (97% identity; SILVA SSU), representing 915 genera belonging to 29 phyla (higher abundant: Actinobacteria, Firmicutes, Bacteroidetes, and Fusobacteria). The presence of a core microbiome was observed (123 shared genera). The alpha diversity analysis showed less bacterial diversity in disease (S-CA) compared to health (S-CF). The dominant genera included Actinomyces, Corynebacterium, Capnocytophaga, Leptotrichia, Veillonella, Prevotella, Streptococcus, Eubacterium, and Neisseria. Veillonella and Leptotrichia were related with disease and Prevotella with health. Corynebacterium, Capnocytophaga, and Actinomyces clustered together presenting high abundance in health and disease. The Metric Multidimensional Scaling Ordination analysis shows that sites from active subjects (ANCL-CA, INCL-CA, and S-CA) are closer to each other than either INCL-CI subjects or S-CF subjects. In conclusion, supragingival bacterial communities presented intra-individual similarities, but inter-individual diversity and difference in bacterial composition reveal that the subject's caries activity status matters more than sites.

Sex differences in the association between obesity and gingivitis among 12-year-old South Brazilian schoolchildren.

OBJECTIVE: To assess the association between weight status and gingivitis in a representative sample of 12-year-old schoolchildren from South Brazil. BACKGROUND: An association between obesity and gingivitis in children and adolescents has been observed; however, the present evidence has major limitations. METHODS: A cross-sectional study was conducted in Porto Alegre, South Brazil, from September 2009 to December 2010 and included a representative sample of 1528 12-year-old schoolchildren attending public and private schools. Data collection included the application of a questionnaire, recording of anthropometric measures (weight and height), and clinical examination (gingival bleeding index, recorded in four sites per tooth). The outcome of the study was the prevalence of gingivitis, defined as the proportion of schoolchildren presenting ≥52% of bleeding sites (based on the median). Weight status was categorized according to body mass index into normal, overweight, or obese. The association between predictor variables and gingivitis prevalence was assessed using Poisson regression models. Unadjusted and adjusted prevalence ratios (PR) and their 95% confidence intervals (95% CI) were estimated. RESULTS: Gingivitis prevalence was 48.7% (95% IC = 33.8-63.6) and, on average, schoolchildren presented 51.8% (95% IC = 46.2-57.5) of bleeding sites. Obese individuals had 13% higher prevalence for presenting gingivitis than did normal-weight ones (PR = 1.13, 95% CI = 1.09-1.18, P < .001). The stratified analysis showed that this association was sex-specific: Obese girls presented a greater chance of having gingivitis (adjusted PR = 1.21, 95% CI = 1.09-1.34, P < .001), but such association was not observed among boys (PR = 1.07, 95% CI = 0.95-1.20, P = .29). CONCLUSION: This study showed sex differences in the association between obesity and gingivitis among 12-year-old South Brazilian schoolchildren.

Low-power laser and potassium oxalate gel in the treatment of cervical dentin hypersensitivity-a randomized clinical trial.

OBJECTIVE: To evaluate the effectiveness of different protocols for the treatment of cervical dentin hypersensitivity (CDH) in non-carious cervical lesions (NCCLs). MATERIALS AND METHODS: The CONSORT checklist was used to design this study. The sample with n = 74 participants (389 NCCLs) was randomly allocated into three groups: G1, potassium oxalate (Oxa-Gel BF); G2, GaAlAs (gallium-aluminum-arsenate) low-power laser (100 mW, 808nn, 60 J/cm2); and G3, potassium oxalate (Oxa-Gel BF) associated with the GaAlAs low-power laser. The CDH was triggered by the evaporative stimulus test (EST) and by the tactile stimulus test (TST). The visual analog scale (VAS) was used to quantify the degree of CDH. Changes in sensitivity were assessed from baseline over 3 weeks. Data were analyzed for NCCLs using mixed-effects models with unstructured direct product covariance structure (α = 0.05). RESULTS: After the first application, participants from G1 and G3 had a reduction in CDH (p < 0.05) compared with group G2 for TST. After the second application, G3 participants had a reduction in CDH (p < 0.05) in relation to G2 for both stimuli. Reduction in CDH (p < 0.05) occurred over 3 weeks for EST and TST for all groups; however, there was no difference between groups at the end of the therapies. CONCLUSION: Potassium oxalate was more effective in reducing immediate CDH. After four applications, all groups showed similar results for the reduction of CDH. CLINICAL RELEVANCE: GaAlAS laser irradiation and oxalate potassium gel could reduce the symptoms of CDH; thus, they are viable alternatives for the treatment of this condition. Chemical occlusion of dental tubules showed effective results after a shorter time interval. TRIAL REGISTRATION: Brazilian Clinical Trials Registration Platform under protocol number RBR-4ybjmt. http://www.braziliantrials.com/?keywords=RBR-4ybjmt&order=%7Eensaios.patrocinador_primario.

Diabetes mellitus and poor glycemic control increase the occurrence of coronal and root caries: a systematic review and meta-analysis.

OBJECTIVES: To assess the occurrence of coronal and root caries in adults with diabetes mellitus (DM). MATERIALS AND METHODS: This study was performed accordingly to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. A search strategy was adapted for six databases, as well as gray literature. The risk of bias was assessed using the Joanna Briggs Institute critical appraisal tools for observational studies. Revman 5.3 was used to conduct five meta-analyses. The quality of evidence of meta-analysis was evaluated by GRADE. RESULTS: From 4047 titles retrieved, 29 studies were included in qualitative synthesis and 20 in quantitative synthesis. Findings showed a higher mean of DMFT in DM individuals compared with healthy controls (mean difference = 1.71; 95% CI 1.08-2.33; p < 0.01; I2 = 55%). Individuals with type 2 DM were three times more likely to have root caries in comparison with non-DM individuals (OR = 3.17; 95% CI 1.19-8.49; p = 0.02; I2 = 70%). Individuals with uncontrolled glycemic levels within the population with DM had higher prevalence of caries than individuals with controlled DM (OR = 3.82; 95% CI 1.12-13.07; p < 0.01; I2 = 89%; DMFT index mean difference = 2.61; 95% CI 1.14-4.08; p < 0.01; I2 = 75%). CONCLUSIONS: Diabetes mellitus may increase the occurrence of coronal and root caries in adults. Poor glycemic control turned diabetic individuals more likely to have caries. CLINICAL RELEVANCE: Dental caries can be an oral sign to indicate poor glycemic control in individuals with DM. Strategies to prevent root caries should be adopted in individuals with type 2 DM. Besides, dental and medical treatments should synergistically explore whether dietary habits are healthy for controlling both, DM and caries.

Responsiveness of Oral Health-Related Quality of Life Questionnaires to Dental Caries Interventions: Systematic Review and Meta-Analysis.

This systematic review and meta-analysis were undertaken to assess the responsiveness of validated oral health-related quality of life (OHRQoL) questionnaires to dental caries interventions in children, adolescents, and young adults. Studies eligible were randomized clinical trials (RCTs), controlled clinical trials (CCTs), and prospective case series (PCS), which had OHRQoL questionnaires answered before and after caries intervention(s). The main outcome was improvement in OHRQoL mean scores following caries intervention. Twenty-six studies were selected for the quality assessment and 14 were selected for the meta-analysis. Most of the studies were PCS with a single group pretest and posttest study design (n = 19). Five studies were CCT and only 2 were RCT. The numbers of participants were 3,522 in the control group (baseline = 2,002; final = 1,520) and 5,917 in the test group (baseline = 3,102; final = 2,815). The age of the subjects ranged from 3 to 19 years. All studies showed significant improvement in OHRQoL following caries intervention. Most of nonrandomized studies (n = 15) had low or moderate risk of bias. The meta-analysis showed the effect of caries interventions (standardized weighted mean differences = -1.24; 95% CI: -1.68 to -0.81; p < 0.001). However, high heterogeneity between the studies was found. The Grading of Recommendations Assessment, Development and Evaluation approach classified the quality of evidence as very low and its strength weak. In conclusion, there is evidence that the OHRQoL of children and adolescents improved following caries intervention procedures, but the quality of the evidence was very low. In spite of that, caries interventions are highly recommended as abstaining from treatment is likely to result in a deterioration of OHRQoL.

Dental erosion among 12-year-old schoolchildren: a population-based cross-sectional study in South Brazil.

OBJECTIVE: To assess the epidemiology and risk indicators for dental erosion among 12-year-old schoolchildren in South Brazil. METHODS: A population-based cross-sectional survey was conducted in Porto Alegre, Brazil, using a representative sample of 12-year-old schoolchildren (n = 1,528). Dental erosion was recorded according to the Basic Erosive Wear Examination (BEWE) index. Parents answered questions on socio-economic status, brushing frequency and general health. Schoolchildren answered questions on dietary habits. Anthropometric data were collected. Statistical analysis included logistic and Poisson regression models. RESULTS: The prevalence of dental erosion was 15% [95% confidence interval (95% CI): 13.6-16.5], being mainly mild erosion. Boys [odds ratio (OR) = 1.57, 95% CI: 1.17-2.10], private school attendees (OR = 1.45, 95% CI: 1.01-2.06) and schoolchildren reporting the daily consumption of soft drinks (OR = 5.04, 95% CI: 1.17-21.71) were more likely to have at least one tooth with dental erosion. Gender [boys, rate ratio (RR) = 1.66, 95% CI: 1.28-2.17], type of school (private, RR = 1.89, 95% CI: 1.53-2.35), the consumption of soft drinks (sometimes: RR = 5.27, 95% CI: 1.46-19.05; daily: RR = 6.82, 95% CI: 1.39-33.50) and the daily consumption of lemon (RR = 1.49, 95% CI: 1.11-2.00) were significantly associated with the number of affected surfaces. CONCLUSIONS: The present study found a moderate prevalence of dental erosion among young schoolchildren, with mild erosion being the most prevalent condition. Socio demographic variables and dietary habits were associated with dental erosion in this population.

Genotypic diversity and virulence traits of Streptococcus mutans isolated from carious dentin after partial caries removal and sealing.

The aim of this study was to compare the genotypic diversity and virulence traits of Streptococcus mutans isolated from carious dentin before and after partial dentin caries removal (PDR) and sealing. Carious dentin samples were obtained three months before and after the PDR and cavity sealing. Up to seven isolates of each morphological type of S. mutans were selected and strain identity was confirmed using gtfB primer. Genotyping was performed by arbitrary primer-PCR (AP-PCR). Acidogenesis and acidurance of the genotypes were evaluated as virulence traits. A paired t-test and a Wilcoxon test were used to compare the virulence of genotypes. A total of 48 representative S. mutans isolates were genotyped (31 before and 17 after the sealing). At least one of the genotypes found before the sealing was also found on dentin after the sealing. The number of genotypes found before the sealing ranged from 2 to 3 and after the sealing from 1 to 2 genotypes. No difference was observed in the acidogenesis and acidurance between genotypes isolated before and after the sealing. In conclusion, genotypic diversity of S. mutans decreased after the PDR and sealing, but the virulence traits of S. mutans remained unchangeable.

The antimicrobial activity of theobromine against cariogenic microbes: an in vitro pilot study.

OBJECTIVE: This pilot study aimed to compare the antimicrobial effect of theobromine, sodium fluoride, and a theobromine-sodium fluoride combination against the following caries-associated bacteria: Streptococcus mutans and Actinomyces naeslundii. METHODOLOGY: Antimicrobial susceptibility was tested via the broth microdilution method, with suspensions cultured on each microbe's respective selective media. Shapiro-Wilk's was completed and all the data showed normality (p > 0.05), and One-way ANOVA was applied to infer the significant differences in the viable counts between the groups. RESULTS: All experimental conditions for both S. mutans and A. naeslundii groups resulted in a significantly lower bacterial abundance in comparison to the control medium, without any active antimicrobial agent (p < 0.001). There was no significant difference in viable count between the theobromine, fluoride, or combination groups against either microbe (p > 0.05). CONCLUSION: Theobromine's antimicrobial activity against S. mutans and A. naeslundii was found similar to that of fluoride, whether used independently or in combination. Further testing of theobromine is necessary to assess its role as an alternative anticaries agent.

The action of microbial collagenases in dentinal matrix degradation in root caries and potential strategies for its management: a comprehensive state-of-the-art review.

Conventional views associate microbial biofilm with demineralization in root caries (RC) onset, while research on their collagenases role in the breakdown of collagen matrix has been sporadically developed, primarily in vitro. Recent discoveries, however, reveal proteolytic bacteria enrichment, specially Porphyromonas and other periodontitis-associated bacteria in subgingivally extended lesions, suggesting a potential role in RC by the catabolism of dentin organic matrix. Moreover, genes encoding proteases and bacterial collagenases, including the U32 family collagenases, were found to be overexpressed in both coronal and root dentinal caries. Despite these advancements, to prove microbial collagenolytic proteases' definitive role in RC remains a significant challenge. A more thorough investigation is warranted to explore the potential of anti-collagenolytic agents in modulating biofilm metabolic processes or inhibiting/reducing the size of RC lesions. Prospective treatments targeting collagenases and promoting biomodification through collagen fibril cross-linking show promise for RC prevention and management. However, these studies are currently in the in vitro phase, necessitating additional research to translate findings into clinical applications. This is a comprehensive state-of-the-art review aimed to explore contributing factors to the formation of RC lesions, particularly focusing on collagen degradation in root tissues by microbial collagenases.

The Archaea domain: Exploring historical and contemporary perspectives with in silico primer coverage analysis for future research in Dentistry.

OBJECTIVE: The complete picture of how the human microbiome interacts with its host is still largely unknown, particularly concerning microorganisms beyond bacteria. Although existing in very low abundance and not directly linked to causing diseases, archaea have been detected in various sites of the human body, including the gastrointestinal tract, oral cavity, skin, eyes, respiratory and urinary systems. But what exactly are these microorganisms? In the early 1990 s, archaea were classified as a distinct domain of life, sharing a more recent common ancestor with eukaryotes than with bacteria. While archaea's presence and potential significance in Dentistry remain under-recognized, there are concerns that they may contribute to oral dysbiosis. However, detecting archaea in oral samples presents challenges, including difficulties in culturing, the selection of DNA extraction methods, primer design, bioinformatic analysis, and databases. DESIGN: This is a comprehensive review on the oral archaeome, presenting an in-depth in silico analysis of various primers commonly used for detecting archaea in human body sites. RESULTS: Among several primer pairs used for detecting archaea in human samples across the literature, only one specifically designed for detecting methanogenic archaea in stool samples, exhibited exceptional coverage levels for the domain and various archaea phyla. CONCLUSIONS: Our in silico analysis underscores the need for designing new primers targeting not only methanogenic archaea but also nanoarchaeal and thaumarchaeota groups to gain a comprehensive understanding of the archaeal oral community. By doing so, researchers can pave the way for further advancements in the field of oral archaeome research.

Traumatic dental injury among 12-year-old South Brazilian schoolchildren: prevalence, severity, and risk indicators.

An increasing prevalence of traumatic dental injury (TDI) has been reported in the last few decades. The aim of this study was to assess the prevalence and severity of TDI and its association with socio-demographics and physical characteristics in the anterior permanent teeth of 12-year-old Brazilian schoolchildren. A cross-sectional study was carried out in a population-based sample of 1528 subjects attending 33 public and nine private schools (response rate of 83.17%). A single calibrated examiner performed the clinical examinations at the schools and recorded the TDI index (Children's Dental Health Survey criteria), overjet and lip coverage. Height and weight were measured to calculate the body mass index (BMI). Parents/legal guardians answered a questionnaire containing socio-demographic questions. The relationships among TDI, socio-demographic variables and physical characteristics were assessed by survey Poisson regression models. The prevalence of TDI was 34.79% (mild trauma = 24.37%; severe trauma = 10.43%). Male schoolchildren (RR = 1.41, 95% CI = 1.23-1.61, P = 0.002) and schoolchildren from low socioeconomic status (RR = 1.32, 95% CI = 1.07-1.64, P = 0.021) were more likely to present at least one tooth with TDI, whereas students attending 7th grade (advanced students) were less likely to experience TDI (RR = 0.59, 95% CI = 0.43-0.82, P = 0.012). Regarding the severity analysis, students of mid-high (RR = 1.46, 95% CI = 1.09-1.94, P = 0.022), mid-low (RR = 1.68, 95% CI = 1.01-2.77, P = 0.045) and low (RR = 1.78, 95% CI = 1.11-2.85, P = 0.027) socioeconomic status were more likely to have mild trauma when compared with schoolchildren of high socioeconomic status. No significant association between severe trauma and socioeconomic status was observed. In conclusion, this study showed a high prevalence of TDI in 12-year-old Brazilian schoolchildren. Socio-demographic data and school achievement were associated with TDI.

Traumatic dental injury with treatment needs negatively affects the quality of life of Brazilian schoolchildren.

BACKGROUND: Traumatic dental injury (TDI) has been considered a significant problem in youth, not only because of its consequences to the craniofacial structures but also for its potential impact on the quality of life of affected individuals. AIM: The aim of this study was to investigate the impact of TDI with treatment needs on the oral health-related quality of life (OHRQoL) of South Brazilian schoolchildren. DESIGN: A cross-sectional study was performed in Porto Alegre, Brazil, using a multistage probability sampling strategy. Of 1837 eligible 12-year-old schoolchildren attending public and private schools, 1528 were examined. OHRQoL was assessed by the Brazilian version of the Child Perceptions Questionnaire for 11-to 14-year-old children (CPQ11-14) - 16-item short form. Clinical examination was conducted to assess the presence of TDI in permanent incisors (Children's Dental Health Survey criteria), malocclusion, and dental caries. Parents/legal guardians answered questions on socioeconomic status. Statistical analyses were performed using Poisson regression models. RESULTS: The overall CPQ11-14 score was not associated with TDI. In the functional limitations domain, individuals presenting TDIs with treatment needs experienced significantly higher mean CPQ11-14 than individuals with no TDI or without treatment needs (RR = 1.21; 95% CI = 1.05-1.39), after adjusting for malocclusion, dental caries, gender, and socioeconomic status. No other domains were associated with TDI. CONCLUSIONS: This study revealed that TDI with treatment needs negatively affects the OHRQoL in this population of 12-year-old schoolchildren and that this impact is related to oral functions.