A dynamic mechanical method to assess bulk viscoelastic behavior of the dentin extracellular matrix

ObjectivesTo develop a protocol for assessment of the bulk viscoelastic behavior of dentin extracellular matrix (ECM), and to assess relationships between induced collagen cross-linking and viscoelasticity of the dentin ECM.MethodsDentin ECM was treated with agents to induce exogenous collagen cross-linking: proanthocyanidins (PACs) from Vitis vinifera – VVe, PACs from Pinus massoniana - PMe, glutaraldehyde – (GA), or kept untreated (control). A dynamic mechanical strain sweep method was carried out in a 3-point bending submersion clamp at treatment; after protein destabilization with 4 M urea and after 7-day, 6-month, and 12-month incubation in simulated body fluid. Tan δ, storage (E’), loss (E”), and complex moduli (E*) were calculated and data were statistically analyzed using two-way ANOVA and post-hoc tests (α = 0.05). Chemical analysis of dentin ECM before and after protein destabilization was assessed with ATR-FTIR spectroscopy.ResultsSignificant interactions between study factors (treatment vs. time points, p < 0.001) were found for all viscoelastic parameters. Despite a significant decrease in all moduli after destabilization, PAC-treated dentin remained statistically higher than control (p < 0.001), indicating permanent mechanical enhancement after biomodification. Covalently crosslinked, GA-treated dentin was unaffected by destabilization (p = 0.873) and showed the lowest damping capacity (tan δ) at all time points (p < 0.001). After 12 months, the damping capacity of PMe and VVe groups decreased significantly. Changes in all amide IR resonances revealed a partial chemical reversal of PAC-mediated biomodification.SignificanceViscoelastic measurements and IR spectroscopy aid in elucidating the role of inter-molecular collagen cross-linking in the mechanical behavior of dentin ECM.     

Risk assessment of malignant transformation of oral leukoplakia in patients with previous oral squamous cell carcinoma

The aim of this study was to identify the risk factors associated with developing oral squamous cell carcinoma (OSCC) from surgically excised oral leukoplakia (OL) in patients with previous oral cavity cancer. Clinicopathological data of 84 patients who were treated for OL between July 2002 and July 2020 and who had previously received treatment for OSCC were reviewed retrospectively. The follow-up time ranged from 0.69 to 17.99 years (mean 6.78 ± 4.25 years). The overall cumulative malignant transformation rate was 25% and the annual transformation rate was 5.73%. Kaplan–Meier survival analysis and the log-rank test showed that Candida infection (P = 0.010) was a risk factor associated with malignant transformation. In the multivariate Cox regression analysis, tongue and floor of the mouth as the location of the leukoplakia (P = 0.039), multifocal lesions of OL (P = 0.047), and Candida infection (P = 0.018) were the three independent prognostic factors related to the development of OSCC from the treated OL. A cautious approach to OL of the tongue with Candida infection or multifocal disease in this group of patients would be appropriate.     

Biofilm on and structural damage of rotary cutting instruments after 5 cycles of clinical use and processing

BackgroundRotary cutting instruments (RCIs) are sterilized routinely. The authors aimed to analyze the structural integrity, presence of dirt, and microbial contamination of RCIs used in clinical practice after processing.MethodsEighty-four RCIs (42 carbide burs, 42 diamond burs) were divided into baseline, control, and test groups. The RCIs were evaluated by means of scanning electron microscopy and microbiological analysis. Evaluation criteria included presence of structural damage, dirt, biofilm, and isolated cells and their phenotypic profile.ResultsThe carbide burs from all groups and diamond burs from the test groups had structural damage. Dirt was observed in the baseline and test groups. Three bacterial species were isolated from 4 RCIs (9.52%). An isolated cell was observed from 1 carbide bur. Biofilm was observed on 3 RCIs (7.14%).ConclusionsRCIs should not be subjected to multiple uses; after the first clinical use they accumulate structural damage and dirt that hampers the cleaning step, causing failure in the sterilization process.Practical ImplicationsThe presence of microorganisms and structural damage on the RCIs confirmed that they are not amenable to processing, a fact that characterizes them as a single-use health care product.     

Effect of concentrated growth factor on lower lip hypoesthesia after osseous genioplasty: a prospective,split-mouth,double-blind randomized controlled trial

Lower lip hypoesthesia is the most common complication following osseous genioplasty. Concentrated growth factor (CGF) has recently been shown to improve neural regeneration. The aim of this study was to evaluate the effect of concentrated growth factor on neurosensory recovery after osseous genioplasty. Patients who underwent osseous genioplasty between June 2017 and February 2020 were enrolled. CGF was applied to the mental nerve on one side. The treatment side was randomized, and the other side was considered as the control. Lower lip hypoesthesia was assessed preoperatively and postoperatively (1 week, 1, 3, 6, and 9 months) using the two-point discrimination test and a 10-point visual analogue scale (self-reported paresthesia). The assessor was blinded. Twenty-six female patients completed the study. At 1 and 3 months, both the mean two-point discrimination value and mean visual analogue scale score were significantly lower in the CGF group than in the control group (P < 0.001). At 3 months, the percentage of patients with lower lip hypoesthesia in the CGF group was significantly lower than that in the control group (P < 0.001). Both groups showed resolution of lower lip hypoesthesia at 6 months. Concentrated growth factor may accelerate the recovery of long-standing sensory nerve impairment following mental osteotomy.     

Effect of full pulpotomy using a calcium silicate–based bioactive ceramic in adult permanent teeth with symptoms indicative of irreversible pulpitis: A retrospective study

BackgroundThe authors studied the treatment effect of full pulpotomy using a calcium silicate–based bioactive ceramic in adult permanent teeth with symptoms indicative of irreversible pulpitis.MethodsEighty-one adult permanent teeth with symptoms indicative of irreversible pulpitis in 78 patients aged 18 through 72 years were evaluated for inclusion in the study. After caries excavation, the pulp was amputated to the level of the canal orifices. After hemostasis was achieved, calcium silicate–based bioactive ceramic was placed as the capping agent. The cavity was sealed temporarily with a glass ionomer cement and then restored with flowable resin and composite resin after 2 weeks if no positive symptoms were reported or detected. Postoperative evaluation was performed by means of clinical and radiographic examination at 2 weeks and 3, 6, and 12 months.ResultsOverall success rates of the procedure were 96.3% (78 of 81), 93.8% (76 of 81), 92.6% (75 of 81), and 92.6% (75 of 81) at the 2-week, 3-month, 6-month, and 12-month recall visits, respectively. Six of the 81 teeth failed and required root canal therapy. In these 6 teeth, 3 exhibited severe cold stimuli pain and spontaneous pain at the 2-week follow-up, 2 had no response to electric pulp testing with apical percussion pain and periapical rarefaction at the 3-month follow-up, and 1 tooth exhibited periapical rarefaction and labial mucosal fistula at the 6-month follow-up.ConclusionsUnder the conditions of this study, full pulpotomy using a calcium silicate–based bioactive ceramic was a successful option for the treatment of adult permanent teeth with carious originated symptoms indicative of irreversible pulpitis.Practical ImplicationsVital pulp therapy is no longer impossible for adult permanent teeth with carious originated symptoms indicative of irreversible pulpitis.     

The influence of periodontal status and serum biomarkers on salivary leptin levels in systemic lupus erythematosus patients

ObjectiveThis study aimed to investigate the influence of periodontal status, clinical data, and serum markers on salivary leptin levels in patients with systemic lupus erythematosus (SLE).MethodsA case–control study was conducted with 38 patients with SLE and 29 healthy controls. Periodontal data included periodontal probing depth (PPD), clinical attachment level (CAL), and gingival bleeding on probing (BOP). Stimulated saliva samples were collected to analyze salivary leptin levels. Clinical and serum data were collected from the SLE group. Statistical analysis included the t-test, Mann–Whitney test, Spearman correlation coefficient, and a structural equation model.ResultsThe SLE group had a lower salivary leptin level than the control group (P = 0.002). The model revealed that SLE had an inverse and independent effect on salivary leptin (standardized estimate =  ? 0.289, P = 0.023). Moreover, salivary leptin level negatively correlated with the serum levels of triglyceride, creatinine, and leukocytes, positively correlated with the serum total cholesterol, but was not significantly correlated with the periodontal status.ConclusionThese findings suggest that patients with SLE have a lower salivary leptin level. In addition, the level of salivary leptin does not appear to be related to periodontal status in patients with SLE.     

The contribution of different permanent tooth types to untreated caries: Implications for public health surveillance and prevention

BackgroundUntreated caries (UC), although highly prevalent, is largely preventable. Information on the contribution of different teeth to UC prevalence and severity could be helpful in evaluating UC surveillance protocols and the relative benefits of caries prevention interventions.MethodsThe authors combined data from 3 cycles (2011-2016) of the National Health and Nutrition Examination Survey for participants aged 6 through 11 years, 12 through 19 years, 20 through 34 years, 35 through 49 years, 50 through 64 years, 65 through 74 years, and 75 years and older. For each age group the authors calculated the contribution of successive permanent tooth types (for example, first molars and second molars) to UC prevalence and severity.ResultsUC prevalence and the percentage of prevalence detected by means of screening molars were, respectively, 5% and 95% among participants aged 6 through 11 years; 16% and 92% among participants aged 12 through 19 years; 29% and 86% among participants aged 20 through 34 years; 26% and 70% among participants aged 35 through 49 years; 21% and 48% among participants aged 50 through 64 years; 16% and 36% among participants aged 65 through 74 years; and 17% and 25% among participants 75 years and older. Among adults aged 50 years and older, no teeth appeared to capture a disproportionate share of UC prevalence. Molars accounted for 87%, 79%, and 56% of severity among participants aged 6 through 11 years, 12 through 19 years, and 20 through 34 years, respectively. After age 34 years, molars accounted for less than 50% of severity.ConclusionsMolars are the tooth type most susceptible to UC well into adulthood.Practical ImplicationsMolars could be used as sentinel teeth for surveillance of UC and adults could benefit from caries prevention that targets molars.     

Impact of antibiotic prophylaxis on the incidence,nature, magnitude,and duration of bacteremia associated with dental procedures: A systematic review

BackgroundAntibiotic prophylaxis (AP) is used routinely in high-risk groups of patients to reduce bacteremia and the risk of developing infective endocarditis (IE). In this systematic review, the authors evaluated the efficacy of AP on the incidence, nature, magnitude, and duration of post-dental procedure bacteremia.MethodsThe authors conducted a systematic search of the literature using MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials up to and including May 2019. They included randomized clinical trials in which researchers compared antibiotics with a placebo or no treatment (as the control). They undertook random-effects meta-analyses to evaluate the incidence of bacteremia after dental procedures.ResultsThe authors included 12 studies in the review. The studies evaluated the incidence of bacteremia after AP with American Heart Association (AHA) protocol antibiotics (amoxicillin, clindamycin, cephalosporin, and azithromycin) or non-AHA protocol antibiotics (moxifloxacin and intravenous [IV] amoxicillin-clavulanic acid). The pooled analysis revealed that antibiotics significantly reduced the bacteremia incidence, but their effectiveness was moderate (risk ratio, 0.50; 95% confidence interval, 0.38 to 0.67). IV amoxicillin-clavulanic acid promoted a considerable reduction in bacteremia. However, in patients with penicillin allergies, antibiotics (that is, clindamycin and cephalosporin) had lower efficacy.Practical ImplicationsOral amoxicillin is still the antibiotic of choice to reduce bacteremia. IV amoxicillin-clavulanic acid could be used for patients at high risk of developing IE who require invasive dental procedures, have high levels of dental infection, and are to be treated under general anesthesia. In patients with penicillin allergies, oral azithromycin showed a higher efficacy for the reduction of bacteremia and the use of clindamycin should be reviewed. Antibiotic premedication should be limited to patients at high risk of developing IE, according to the indications of the AHA guide.     

Association of MMP9, MMP13 and MMP20 genes polymorphism with dental caries: A meta-analysis

ObjectivesGenetic factors can be involved in dental caries as the most common chronic oral diseases. The association between polymorphism of MMP9, MMP13 and MMP20 genes with tooth decay has been studied but contradictory outcomes have been indicated. Thus, a meta-analysis was done to get comprehensive outcomes in this path.Materials and methodsAll articles in English by March 2022 were searched with correlated keywords from known database as PubMed, Scopus, Embase and Web of Science, and the articles were selected in several stages based on exclusion and inclusion criteria. Comprehensive meta-analysis software v.2.0 was used for Meta-analysis.ResultsFinally, 11 related articles were selected for meta-analysis. According to the results, MMP9 and MMP20 polymorphisms were not related with increased susceptibility to caries in the studied models, but in the case of MMP13, a significant association was observed between gene polymorphism and caries risk.ConclusionThe results about MMP13 gene polymorphism showed that guanine G allele and GG genotype have a protective role and decrease the risk of dental caries. It should be noted that, these conclusions could be promoted by studies contain large sample sizes. Finding the genetic factors influencing tooth decay can help increase our current knowledge of caries pathology, predict its occurrence, and target genes at the molecular level to prevent it.     

Saliva diagnostics: Salivaomics,saliva exosomics,and saliva liquid biopsy

BackgroundEach day, humans produce approximately 0.5 through 1.5 liters of saliva, a biofluid that is rich in biological omic constituents. Our lack of understanding how omic biomarkers migrate from diseased tissue to the saliva has impeded the clinical translation of saliva testing. Although such biomarkers must be conveyed via the vascular and lymphatic systems to the salivary glands, the molecular mechanisms that underlie this transport remain unclear. Although COVID-19 highlighted the need for rapid and reliable testing for infectious diseases, it represents only one of the many health conditions that potentially can be diagnosed using a saliva sample.Types of Studies ReviewedThe authors discuss salivaomics, saliva exosomics, and the mechanisms on which saliva diagnostics are based and introduce a novel electrochemical sensing technology that may be exploited for saliva liquid biopsy.ResultsThe utility of saliva for screening for lung cancer is under investigation. Saliva testing may be used to stratify patients, monitor treatment response, and detect disease recurrence. The authors also highlight the landscapes of saliva-based SARS-CoV-2 testing and ultrashort cell-free DNA and outline how these fields are likely to evolve in the near future.Practical ImplicationsBreakthroughs in the study of saliva research, therefore, will facilitate clinical deployment of saliva-based testing.     

Systematic review and meta-analysis on the effect of self-assembling peptide P11-4 on arrest,cavitation, and progression of initial caries lesions

BackgroundSimple noninvasive evidence-based interventions for caries are needed to overcome limitations in the restorative paradigm. The self-assembling peptide P₁₁-4 is a noninvasive intervention that regenerates enamel in initial caries lesions.Studies ReviewedThe authors conducted a systematic review and meta-analysis on the effectiveness of the P₁₁-4 products Curodont Repair (Credentis; now manufactured by vVARDIS) (CR) and Curodont Repair Fluoride Plus (Credentis; now manufactured by vVARDIS) on initial caries lesions. Primary outcomes were lesion progression after 24 months, caries arrest, and cavitation. Secondary outcomes were changes in merged International Caries Detection and Assessment System score categories, quantitative light-induced fluorescence (QLF; Inspektor Research System), esthetic appearance, and lesion size.ResultsSix clinical trials met the inclusion criteria. Results of this review represent 2 primary and 2 secondary outcomes. When compared with parallel groups, use of CR likely results in a large increase in caries arrest (relative risk [RR], 1.82 [95% CI, 1.32 to 2.50]; 45% attributable risk [95% CI, 24% to 60%]; number needed to treat [NNT], 2.8) and likely decreases lesion size by a mean (SD) of 32% (28%). The evidence also suggests that use of CR results in a large reduction in cavitation (RR, 0.32 [95% CI, 0.10 to 1.06]; NNT, 6.9) and is uncertain about lowering merged International Caries Detection and Assessment System score (RR, 3.68 [95% CI, 0.42 to 32.3]; NNT, 19). No studies used Curodont Repair Fluoride Plus. No studies reported adverse esthetic changes.Practical ImplicationsCR likely has clinically important effects on caries arrest and decreased lesion size. Two trials had nonmasked assessors, and all trials had elevated risks of bias. The authors recommend conducting longer trials. CR is a promising treatment for initial caries lesions. The protocol for this systematic review was registered a priori with PROSPERO (304794).     

An immunohistochemical study of matrix components in primary and secondary cartilages of embryonic chick skull

ObjectivesThis study aimed to compare the extracellular matrix of primary cartilage with the secondary cartilage of chicks using immunohistochemical analyses in order to understand the features of chick secondary chondrogenesis.MethodsImmunohistochemical analysis was performed on the extracellular matrix of quadrate (primary), squamosal, surangular, and anterior pterygoid secondary cartilages using various antibodies targeting the extracellular matrix of cartilage and bone.ResultsThe localization of collagen types I, II, and X, versican, aggrecan, hyaluronan, link protein, and tenascin-C was identified in the quadrate cartilage, with variations within and between the regions. Newly formed squamosal and surangular secondary cartilages showed simultaneous immunoreactivity for all molecules investigated. However, collagen type X immunoreactivity was not observed, and there was weak immunoreactivity for versican and aggrecan in the anterior pterygoid secondary cartilage.ConclusionsThe immunohistochemical localization of extracellular matrix in the quadrate (primary) cartilage was comparable to that of long bone (primary) cartilage in mammals. The fibrocartilaginous nature and rapid differentiation into hypertrophic chondrocytes, which are known structural features of secondary cartilage, were confirmed in the extracellular matrix of squamosal and surangular secondary cartilages. Furthermore, these tissues appear to undergo developmental processes similar to those in mammals. However, the anterior pterygoid secondary cartilage exhibited unique features that differed from primary and other secondary cartilages, suggesting it is formed through a distinct developmental process.     

Systematic review and meta-analysis of randomized controlled studies comparing oscillating-rotating and other powered toothbrushes

BackgroundThe aim of this study was to systematically review and analyze the difference in efficacy of oscillating-rotating toothbrushes compared with other powered toothbrushes.MethodsThe authors performed a systematic search of the literature according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The authors used the population, intervention, comparison, and outcome format to develop a search strategy to answer the study question. The authors searched PubMed-MEDLINE databases. Inclusion criteria were randomized controlled clinical trials comparing oscillating-rotating (OR) toothbrushes with other powered toothbrushes published from January 1, 2009 through March 1, 2019.ResultsThe authors’ search resulted in 454 articles; 21 articles were downloaded for review, 15 articles were included in the report, and 12 could be used for meta-analysis. All of the studies were randomized controlled clinical trials that assessed plaque removal and gingival inflammation indexes. Results of the meta-analysis of the randomized controlled clinical trials showed that OR toothbrushes had superior, statistically significant outcomes for whole-mouth plaque reduction, assessed using the Rustogi Modified Navy Plaque Index (P < .01), and gingivitis, assessed by using number of bleeding sites (P < .001), but not for the modified gingival index (P > .05) or gingival bleeding index (P > .05).Practical ImplicationsThere is some evidence to suggest that OR powered toothbrushes might remove more plaque and reduce the number of bleedings sites better than other powered toothbrushes, specifically, sonic action toothbrushes.     

Periodontal tissue regeneration by recombinant human collagen peptide granules applied with β-tricalcium phosphate fine particles

ObjectivesRecombinant human collagen peptide (RCP) is a recombinantly created xeno-free biomaterial enriched in arginine-glycine-aspartic acid sequences with good processability whose use for regenerative medicine applications is under investigation. The biocompatibility and osteogenic ability of RCP granules combined with β-tricalcium phosphate (TCP) submicron particles (β-TCP/RCP) were recently demonstrated. In the present study, β-TCP/RCP was implanted into experimental periodontal tissue defects created in beagles to investigate its regenerative effects.MethodsAn RCP solution was lyophilized, granulated, and thermally cross-linked into particles approximately 1 mm in diameter. β-TCP dispersion (1 wt%; 500 μL) was added to 100 mg of RCP granules to form β-TCP/RCP. A three-walled intrabony defect (5 mm × 3 mm × 4 mm) was created on the mesial side of the mandibular first molar and filled with β-TCP/RCP.ResultsA micro-computed tomography image analysis performed at 8 weeks postoperative showed a significantly greater amount of new bone after β-TCP/RCP grafting (2.2-fold, P < 0.05) than after no grafting. Histological findings showed that the transplanted β-TCP/RCP induced active bone-like tissue formation including tartaric acid-resistant acid phosphatase– and OCN-positive cells as well as bioabsorbability. Ankylosis did not occur, and periostin-positive periodontal ligament-like tissue formation was observed. Histological measurements performed at 8 weeks postoperative revealed that β-TCP/RCP implantation formed 1.7-fold more bone-like tissue and 2.1-fold more periodontal ligament-like tissue than the control condition and significantly suppressed gingival recession and epithelial downgrowth (P < 0.05).Conclusionsβ-TCP/RCP implantation promoted bone-like and periodontal ligament–like tissue formation, suggesting its efficacy as a periodontal tissue regenerative material.