Alejandro Donohue-Cornejo

Background: Motor and intellectual disabilities (MIDs) belong to a restricted and vulnerable social group with health restrictions for maintaining and preserving adequate oral health. Silver nanoparticles (AgNPs) have appeared as an encouraging therapy due to their excellent antimicrobial effects; however, scientific information on the antimicrobial effectiveness of AgNPs against bacteria in patients with MIDs remains limited. This study aimed to evaluate the antimicrobial substantivity of AgNPs in oral bacteria from patients with and without MIDs. Methods: Fifty-four oral biofilm samples were obtained from 26 participants with MIDs and 28 participants without MIDs. The microbial inhibition activity and the antimicrobial substantivity of AgNPs were determined. The antibiofilm activity of the AgNPs was explored using scanning electron microscopy (SEM). Results: The AgNPs displayed uniform size distributions (9.8 ± 1.7 nm) and electrical charges in surface particles that limit particle clustering (−39.8 ± 3.3 mV). The AgNPs were more effective than chlorhexidine (CHX) in eliminating bacteria from oral biofilms derived from both MID and non-MID patients (p < 0.05); therefore, the antimicrobial substantivity of the AgNPs was statistically better than deionized water but lower than CHX at specific exposure times (p < 0.05). The antimicrobial effectiveness of AgNPs at even low concentrations was associated with the type of oral biofilm, the type of antimicrobial solution, and, in some cases, gender. SEM images indicate a clear alteration in oral biofilm structure when AgNPs were applied. Conclusions: AgNPs exhibited significant potential to limit oral bacterial proliferation from microbial biofilms while contributing to the maintenance of oral condition in individuals with MIDs.

Background/Objectives. Oral epithelial dysplasia exhibits unpredictable behavior, prompting research to identify biomarkers that may help predict its progression to malignancy. This study aimed to ascertain the prognostic value of biomarkers indicative of the epithelial–mesenchymal transition (EMT) process using immunohistochemistry. Methods. A systematic review was conducted using PubMed data from 1978 to June 2026. Articles that employed immunohistochemistry to identify cells exhibiting epithelial–mesenchymal transition changes in oral epithelial dysplasia were included. Exclusion criteria included in vivo studies, book chapters, reviews, conference abstracts, and studies lacking population descriptions. The risk of bias was assessed using the “JBI Checklist for Critical Appraisal of Case Series”. Results. A total of 21 articles were included, analyzing 57 biomarkers: 34 epithelial, 19 mesenchymal, two cell-proliferation biomarkers, and two tumor-suppressor biomarkers. The sample sizes varied significantly between the studies. Most articles employed semiquantitative assessment, cell percentage, and immunostaining intensity, with 12 demonstrating low risk of bias. Conclusions. Studies with conclusive results and a low risk of bias suggest that E-cadherin and Vimentin are valuable biomarkers for identifying early EMT in OED. However, the lack of statistical support means that this assertion should be viewed with caution.

Background/Objectives: Root canal infections represent a serious challenge to the success of endodontic treatment. The most commonly used antimicrobial irrigants, such as sodium hypochlorite (NaOCl), have certain limitations, while endodontic biofilms pose a significant microbiological complexity in the endodontic field. Silver nanoparticles (AgNPs) have emerged as a promising irrigant option in root canal treatments; however, few studies are focusing on endodontic biofilms. This work aimed to evaluate the antimicrobial and anti-adherence properties of AgNPs against clinically isolated bacteria taken directly from patients with various pulp and periapical diseases. Methods: AgNPs of two sizes were synthesized and characterized. The bactericidal and anti-adherence activities of AgNPs were evaluated through microbiological assays using experimental in vitro and ex vivo tests on oral biofilms taken from patients with symptomatic apical periodontitis (AAP) and pulp necrosis (PN). NaOCl solution was used as the gold standard. Results: The size of AgNPs was uniformly distributed (13.2 ± 0.4 and 62.6 ± 14.9 nm, respectively) with a spherical shape. Both types of nanoparticles exhibited good antimicrobial and anti-adherence activities in all microbiological assays, with a significant difference from NaOCl for in vitro and ex vivo models (p < 0.05). The inhibitory activity of AgNPs is mainly related to the type of microbiological sample and the exposure time. The antibacterial substantivity of both nanoparticle sizes was time-dependent. Conclusions: AgNPs may represent a promising antimicrobial option as an endodontic irrigant during conventional root canal treatments to prevent and control endodontic infections.

The primary objective of this investigation was to synthesize a resin incorporating nanoparticles of hydroxyapatite and silver (HA-NpsAg) to enhance biocompatibility and antimicrobial efficacy, thereby facilitating potential implementation within the dental industry. These enhancements aim to ensure reliable, durable, functional, and aesthetically pleasing restorations while concurrently reducing susceptibility to bacterial colonization within the oral cavity. Hydroxyapatite powders were prepared using the sol–gel method and doped with silver nanoparticles obtained by chemical reduction. The crystalline amorphous calcium phosphate powder had a particle size of 279 nm, and the silver nanoparticles had an average diameter of 26.5 nm. Resin spheres containing HA-NpsAg (RHN) were then synthesized at two concentrations (0.5% and 1%) by dissolving the initial monomer mixture in tetrahydrofuran. Subsequent antimicrobial evaluations were conducted via agar diffusion and turbidimetry, employing three strains of Gram-negative bacteria (E. coli, K. oxytoca, and P. aeruginosa) and three strains of Gram-positive bacteria (S. mutans, S. aureus, and B. subtilis). The findings revealed that P. aeruginosa exhibited maximum susceptibility to RHN powder at a concentration of 0.5%, while RHN powder at 1% concentration demonstrated maximal inhibition against S. aureus and S. mutans. Overall, our study highlights the successful synthesis of a dental resin with hydroxyapatite and silver nanoparticles, exhibiting bactericidal properties at low silver concentrations. These findings hold promise for enhancing dental materials with improved antimicrobial efficacy and clinical performance.

Background: Motor and intellectual disabilities (MIDs) represent a great challenge for maintaining general health due to physical and cognitive limitations, particularly in the maintenance and preservation of oral health. Silver nanoparticles (AgNPs) have emerged as a promising therapeutic tool for bacterial control, including oral biofilms; however, knowledge of the bactericidal effectiveness of oral biofilms from patients with MIDs is insufficient. This study aims to determine the antimicrobial effect of AgNPs on different oral biofilms taken from patients with and without MIDs. Methods: Two sizes of AgNPs were prepared and characterized by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Through consecutive sampling, biofilm samples were collected from 17 subjects with MIDs and 20 subjects without disorders. The antimicrobial effect was determined by obtaining the minimum inhibitory concentration (MIC) of AgNPs, and the identification and distribution of oral bacterial species were determined by polymerase chain reaction (PCR). Finally, correlations between sociodemographic characteristics and the antimicrobial levels of AgNPs were also explored. The values of the MIC results were analyzed with IBM-SPSS software (version25) using non-parametric tests for independent groups and correlations, with statistical significance being considered as p < 0.05. Results: Both sizes of AgNPs exhibited tight particle size distributions (smaller: 10.2 ± 0.7 nm; larger: 29.3 ± 2.3 nm) with zeta potential values (−35.0 ± 3.3 and −52.6 ± 8.5 mV, respectively) confirming the stability that resulted in little to no agglomeration of nanoparticles. Although both sizes of AgNPs had good antimicrobial activity in all oral biofilms, the smallest particles had the best antimicrobial effects on the oral biofilm samples from patients with and without MIDs, even better than chlorhexidine (CHX) (p < 0.05). Likewise, the patients with disabilities showed higher levels of antimicrobial sensitivity to AgNPs compared with CHX (p < 0.05). Although the microorganisms included in the biofilms of females had a statistically higher growth level, the AgNP antimicrobial effect was statistically similar in both genders (p > 0.05). The most frequent bacteria for all oral biofilms were S. mutans (100%), P. intermedia (91.6%), T. forsythia (75.0%), T. denticola (75.0%), P. gingivalis (66.6%), F. nucleatum (66.6%), S. sobrinus (50.0%), and A. actinomycetemcomitans (8.3%). Conclusions: AgNPs exhibited considerable antimicrobial potential to be used as a complementary and alternative tool in maintaining and preserving oral health in patients with MIDs.

Backgroud: Antibiotics are a type of medication routinely prescribed by dental professionals; however, it is very common that the administration is not justified. Around 15% of dentists admit that they have administered antibiotics unnecessarily more than once a week. The objective of this project is to identify the effectiveness of the use of antibiotics as prophylactic therapy in oral surgery, and to carry out an analysis of the alternatives to pharmacological therapy. Methods: The search strategy was carried out in the PubMed, Scopus, and ScienceDirect databases. For study selection, a first filter was carried out by title and abstract, which mentioned the use of prophylactic antibiotics in some type of oral surgery. To establish the risk of bias, the JBI Critical Appraisal Checklist for Randomized Controlled Trials was utilized. Results: The type of antibiotics most prescribed as prophylactic therapy were beta-lactams, which were indicated in 100% of the studies. Penicillins predominated, observing amoxicillin as the most indicated drug in 54.1% of the studies (n = 13) followed by the use of amoxicillin in conjunction with clavulanic acid in 33.3% of the studies (n = 8). Of the 21 studies included, 17 mention that there is insufficient evidence to support the use of antibiotics as prophylactic therapy in patients who will undergo some type of oral surgery. Conclusions: Without a doubt, the biggest challenge is to develop academic update strategies aimed at dentists with active clinical practice and dental students from educational and government institutions to provide updated information about the correct use of prescription drugs.

Background and Objectives: Periodontal disease (PD) is a multifactorial oral disease regularly caused by bacterial biofilms. Silver nanoparticles (AgNP) have offered good antimicrobial activity; moreover, there is no available scientific information related to their antimicrobial effects in biofilms from patients with PD. This study reports the bactericidal activity of AgNP against oral biofilms related to PD. Materials and Methods: AgNP of two average particle sizes were prepared and characterized. Sixty biofilms were collected from patients with (30 subjects) and without PD (30 subjects). Minimal inhibitory concentrations of AgNP were calculated and the distribution of bacterial species was defined by polymerase chain reaction. Results: Well-dispersed sizes of AgNP were obtained (5.4 ± 1.3 and 17.5 ± 3.4 nm) with an adequate electrical stability (−38.2 ± 5.8 and −32.6 ± 5.4 mV, respectively). AgNP showed antimicrobial activities for all oral samples; however, the smaller AgNP had significantly the most increased bactericidal effects (71.7 ± 39.1 µg/mL). The most resistant bacteria were found in biofilms from PD subjects (p < 0.05). P. gingivalis, T. denticola, and T. forsythia were present in all PD biofilms (100%). Conclusions: The AgNP showed efficient bactericidal properties as an alternative therapy for the control or progression of PD.

Background: It is estimated that up to 90% of head and neck infections have an odontogenic origin, which are considered among the most common in the oral cavity and maxillofacial region. Bacterial resistance has been 1 of the main problems related to the treatment of this type of infection in recent years. The frequency of this resistance is increasing, which is mainly due to patient self-medication and the mutations that bacteria present. Therefore, the objective of this study is to analyze the antimicrobial resistance of antibiotics commonly administered for the treatment of odontogenic infections. Method: To carry out the study, PubMed, ScienceDirect, and Scopus databases were reviewed using the keywords “odontogenic infection”, “pharmacological treatment”, and “microbial resistance. Studies whose main objective was the pharmacological treatment of odontogenic infections were selected. Exclusions were review-type studies, systematic reviews, or in vitro or animal model studies. For the analysis of risk of bias, the Checklist for Analytical Cross-Sectional Studies of the Joanna Briggs Institute was used. The search and analysis of the studies was carried out by 2 researchers independently. Results: A total of 13 studies were included in this review. The mean age was 39.6 years; the location of the infection in the study subjects was in the submandibular and vestibular spaces; there were periodontal, periapical, and dentoalveolar lesions; the main microorganisms identified were Streptococcus, Staphylococcus, Prevotella, Peptostreptococcus, Clostridium, and Klebsiella; and finally, the main microorganisms identified for bacterial resistance were penicillin, clindamycin and amoxicillin. Conclusion: The health professional is obliged to update their knowledge to avoid such antibiotic resistance and thus provide better patient care.

Oral squamous cell carcinoma is a neoplasm that originates from the epithelial mucosa. It is usually more frequent between the fifth and sixth decades of life, and more than 90% of carcinomas of the oral cavity are squamous cell carcinoma. It is an invasive neoplasia with a significant recurrence rate; 40% of patients present with metastases in the cervical lymph nodes at the time of diagnosis. The tumor invasion front is a characteristic of tumor growth, which can be infiltrative or noninvasive. The histopathological parameters examined include the number of mitoses, depth of the tumor, invasion pattern, degree of keratinization, and nuclear pleomorphism. For the pathologist, these parameters are routinely evaluated but are not reported to the treating physician in all cases, which we consider to be useful information when determining the therapeutic route.

Background and Objectives: Streptococcus mutans (S. mutans) is the main microorganism associated with the presence of dental caries and specific serotypes of this bacteria have been related to several systemic diseases limiting general health. In orthodontics, white spot lesions (WSL), represent a great challenge for clinicians due to the great fluctuation of their prevalence and incidence during conventional orthodontic treatments. Although silver nanoparticles (AgNP) have been demonstrated to have great antimicrobial properties in several microorganisms, including S. mutans bacteria, there is no available information about anti adherence and antimicrobial properties of AgNP exposed to two of the most relevant serotypes of S. mutans adhered on orthodontic materials used for conventional therapeutics. The objective of this study was to determine anti-adherence and antimicrobial levels of AgNP against serotypes c and k of S. mutans on conventional orthodontic appliances. Materials and Methods: An AgNP solution was prepared and characterized using dispersion light scattering (DLS) and transmission electron microscopy (TEM). Antimicrobial and anti-adherence activities of AgNP were determined using minimal inhibitory concentrations (MIC) and bacterial adherence testing against serotypes c and k of S. mutans clinically isolated and confirmed by PCR assay. Results: The prepared AgNP had spherical shapes with a good size distribution (29.3 ± 0.7 nm) with negative and well-defined electrical charges (−36.5 ± 5.7 mV). AgNP had good bacterial growth (55.7 ± 19.3 µg/mL for serotype c, and 111.4 ± 38.6 µg/mL for serotype k) and adherence inhibitions for all bacterial strains and orthodontic wires (p < 0.05). The serotype k showed statistically the highest microbial adherence (p < 0.05). The SS wires promoted more bacterial adhesion (149.0 ± 253.6 UFC/mL × 10⁴) than CuNiTi (3.3 ± 6.0 UFC/mL × 10⁴) and NiTi (101.1 ± 108.5 UFC/mL × 10⁴) arches. SEM analysis suggests CuNiTi wires demonstrated better topographical conditions for bacterial adherence while AFM evaluation determined cell wall irregularities in bacterial cells exposed to AgNP. Conclusions: This study suggests the widespread use of AgNP as a potential anti-adherent and antimicrobial agent for the prevention of WSL during conventional orthodontic therapies and, collaterally, other systemic diseases.